Fukushima nuclear disaster
As Fukushima nuclear disaster a number of catastrophic accidents and severe accidents in Japan are Fukushima Daiichi Nuclear Power Plant ( Fukushima I ) and their effects referred.
The series of accidents began on March 11, 2011 at 2:47 pm (local time) with the Tōhoku earthquake and ran simultaneously in four of six reactor blocks . Core meltdowns occurred in Units 1 to 3 . Large amounts of radioactive material - about 10 to 20 percent of the radioactive emissions of the Chernobyl nuclear disaster - were released and contaminated air, soil, water and food in the agricultural and sea side environment. Around 100,000 to 150,000 residents had to leave the area temporarily or permanently. Hundreds of thousands of animals left on farms starved to death. However, no human deaths from exposure to radiation were known.
On the basis of an estimate of the total radioactivity of the released substances , the Japanese nuclear regulatory authority classified the events on the international rating scale for nuclear events with the highest level 7 ("catastrophic accident").
Four out of six reactor blocks in the power plant were destroyed by the accidents. According to a statement by the Japanese government on March 20, 2011, the power plant is to be completely abandoned. Since December 2013, the IAEA has listed all six reactors of the power plant as "permanently shut down". The disposal work is expected to take 30 to 40 years.
Reporting on the disaster led in many countries to greater skepticism or a change in sentiment at the expense of civilian use of nuclear energy . Several countries gave up their nuclear energy programs.
Sources of information
Most of the information available about what is happening on the power plant site comes directly or indirectly from the operating company Tokyo Electric Power Company (Tepco). They were published partly directly by Tepco on the Internet and at press conferences, partly via regular reports or press conferences of the Japanese nuclear supervisory authority (NISA), the higher-level Ministry of Economic Affairs ( METI ) and the government spokesman . The Japanese government was involved in the crisis management team at the Tepco company headquarters. The NISA was on site with its own experts who, however, did not take any measurements, only checked the information provided by the operator for plausibility.
The Japanese Nuclear Industry Forum (JAIF) published status reports on its website several times a day on the situation in the power plant and on other events in connection with the accidents.
The few publicly available information from the power plant site that is independent of Tepco includes recordings and measurements made from outside, for example aerial photographs and satellite images, other photo and video recordings and radiation measurement data from unmanned US reconnaissance aircraft. There are also reports from employees at the power plant.
Measured values from various sources are available from the wider area in Japan, for example from government agencies such as the Japanese Ministry of Culture and Technology (MEXT), the Ministry of Health (MHLW) and the disaster control command established after the nuclear emergency was declared, from regional authorities and organizations, by private individuals and by international observers.
The German Society for Plant and Reactor Safety (GRS) collects and evaluates information on the accidents on behalf of the Federal Environment Ministry and relies on the sources mentioned above. The International Atomic Energy Agency (IAEA) and many other specialist organizations and publications also evaluate the data from Japan and report on them regularly.
Organizations around the world such as the IAEA, the Organization of the Comprehensive Nuclear-Test-Ban Treaty (CTBTO) and the Environmental Protection Agency published data from their sensitive measuring points on the spread of radioactive particles from Fukushima .
Tepco, the Japanese government, the IAEA and a commission of experts set up by the Kan government published the first detailed investigative reports.
Construction of the power plant
The Fukushima I nuclear power plant consists of six reactor blocks, each with a boiling water reactor . In addition to the nuclear reactor , each reactor building also has a cooling pool for the interim storage of spent fuel elements . There is also a larger, central cooling pool and a dry fuel storage facility with special containers on the power plant site. A further building is attached to each reactor building, in which the turbines and generators for generating electricity as well as the inlets and outlets for cooling water from the sea are located.
Reactors and cooling pools must be continuously cooled, even when they are switched off. In used or "burned off" elements, atoms with a short half-life that were created during nuclear fission ( fission products ) continue to decay . This releases heat ( decay heat ) that would destroy the fuel elements without adequate cooling. In each reactor block there are therefore several cooling circuits that are also designed redundantly .
Sequence of accidents in the power plant
Starting position
Before the accidents, there were indications of the risks of the reactor types used and construction defects of the plant in Fukushima Daiichi , inadequate protection against earthquakes and tsunamis, and inadequate control and maintenance . Tepco and the Japanese nuclear regulators ignored most of this advice.
At the time of the quake, reactor units 1, 2 and 3 were in operation. Reactor unit 4 has been out of operation since November 30, 2010 due to a major overhaul; the fuel elements in this unit were therefore completely stored in the associated decay pool at the time of the accident. Units 5 and 6 were shut down on January 3, 2011 and August 14, 2010, respectively, and were re-equipped with fuel assemblies as part of maintenance. In contrast to units 1 and 2, reactor 3 has also had mixed oxide fuel elements since August 2010 , which contain a mixture of uranium dioxide and plutonium dioxide . Each of the fuel assemblies consisted of 72 (reactor 3 differently 74) fuel rods and contained 170 to 173 kilograms of nuclear fuel .
The following number of fuel elements and the mass of nuclear fuel were located in the reactor cores, decay pool and storage pool:
| Storage location | Fuel assemblies | Cooling pool | ||||||
|---|---|---|---|---|---|---|---|---|
| in the reactor core | in the cooling pool | of which unused | Estimated heat output ( kW ) |
Volume (m³) |
||||
| number | Mass (t) |
number | Mass (t) |
number | Mass (t) |
|||
| Block 1 | 400 | 68 | 392 | 67 | 100 | 17th | 180 | 1,020 |
| Block 2 | 548 | 94 | 615 | 105 | 28 | 5 | 620 | 1,425 |
| Block 3 | 548 | 94 | 566 | 97 | 52 | 9 | 540 | 1,425 |
| Block 4 | 0 | 0 | 1,535 | 263 | 204 | 35 | 2,260 | 1,425 |
| Block 5 | 548 | 94 | 994 | 171 | 48 | 8th | 1,000 | 1,425 |
| Block 6 | 764 | 132 | 940 | 162 | 64 | 11 | 870 | 1,497 |
| Central cooling pool | 6,375 | 1,093 | 1,130 | 3,828 | ||||
| total | 2,808 | 480 | 11,417 | 1,958 | 496 | 85 | 6,600 | 12,045 |
- ↑ The table shows estimates as of November 9, 2012 from a report by the Japanese authorities to the IAEA. There are various different estimates, some of them lower and some of them higher. The heat output in the cooling basins from Blocks 1 to 6 was reduced by 10–30 percent within three months.
- ↑ including 32 mixed oxide fuel elements
- ↑ estimated on the basis of an average fuel mass of 0.1715 t per fuel element
Tepco estimated the total amount of radioactive 131 I contained in the fuel rods to be 81 · 10 18 Becquerel or 81 million Terabecquerel.
In addition, there were at least 10,000 tons of contaminated water in the power plant's waste storage facility.
Accident series from March 11th to 16th
On March 11, 2011 at 14:46:23 (local time), the Tōhoku earthquake began under the seabed off the east coast of the Japanese main island of Honshū . Its epicenter was 163 kilometers northeast of the Fukushima I power plant, meaning that the primary waves (P waves) of the quake had reached the power plant site after 23 seconds. There they stimulated seismometers , which triggered a rapid shutdown of reactors 1 to 3. At the same time, the power plant's external power supply failed due to earthquake damage to its switchgear , and twelve of thirteen emergency diesel generators started (one at Block 4 was being serviced).
The quake lasted about two minutes and reached a magnitude of 9.0 M w . It shook reactor blocks 2, 3 and 5 with horizontal accelerations of 0.52 to 0.56 g , 15 to 26 percent more than assumed when the blocks were designed. The planned load limits of the other reactors were not reached; nevertheless there are indications of earthquake damage in block 1 . In Block 3, a reserve emergency cooling system was probably damaged.
All six blocks switched to emergency cooling.
From 3:35 p.m., tsunami waves with a height of approximately 13 to 15 meters hit the power plant. According to the IAEA, Fukushima I was not connected to the existing tsunami warning system, so that the operating personnel did not receive an early warning, while NISA speaks of an alarm immediately after the earthquake. There was only a 5.70 meter high protective wall for the sea-side part of the site; only 3.12 meters were required. The reactor blocks 1 to 4, which are 10 meters above sea level, were flooded up to 5 meters deep; the three meters higher built blocks 5 and 6 up to one meter. The seawater pumps positioned on the coast were destroyed; Waste heat could no longer be released into the sea water, which ran into various buildings and flooded five of the twelve running emergency power generators and most of the power distribution cabinets. The power plant operator Tepco reported that the generators failed at 3:41 p.m. A generator in Block 6 survived the tsunami because it was housed in a separate, higher building.
400 Tepco employees were mobilized for emergency operations - according to the IAEA far too few for a catastrophe of this magnitude. External companies such as power plant manufacturers Toshiba and Hitachi withdrew their employees. Simultaneous accidents in several blocks were not included in the emergency plan. Alluvial debris, puddles of water, road damage and inoperable door and gate openers hindered further work. Most of the communication facilities were down. There was a constant risk of aftershocks and further tsunamis.
Due to the failure of the power supply ( blackfall or station blackout ), sufficient cooling was no longer guaranteed to dissipate the decay heat from the reactor cores and cooling basins. With the existing emergency batteries, the emergency cooling systems could only be operated briefly (see section Problems in reactors 1 to 3 ). Additional generator vehicles that were brought in became active too late to stop the series of accidents due to traffic jams, blocked access routes, flooded connection points and cables that were too short. Only in blocks 5 and 6 could the power supply be restored in good time by the still functional generator. In Blocks 1 through 3, workers tried, with varying degrees of success, to connect car batteries and portable power generators to individual systems.
A lack of cooling, partly due to other technical and organizational problems, resulted in overheating of the reactors and cooling pool, the release of hydrogen into the reactor buildings and core meltdowns in reactors 1 to 3 (see sections Problems in Reactors 1 to 3 and Problems in the cooling pool ). Through targeted pressure relief of the reactors radioactive substances got into the environment and were distributed further in different directions by changing winds.
From March 12 to 15, there were explosions - probably hydrogen explosions - in units 1, 3 and 4, some of which severely damaged the reactor buildings and set the rescue work back. Highly radioactive rubble was hurled onto the power plant site. In Block 2 the containment of the reactor was damaged, so that extremely highly contaminated water escaped (see also section sea water channels ); Several fires broke out in Block 4. From March 13th to 15th, neutron radiation was measured several times on the power plant site , which indicated an uncontrolled restart of nuclear fission ( criticality ) in one of the reactors or decay basins.
The plant fire brigade pumped water into reactors 1 to 3 in order to cool them down, first from existing fresh water reserves and then from pits in which seawater had accumulated. Prime Minister Naoto Kan gave permission to discharge seawater - this will damage the reactors - on March 12, 2011 at 7:55 pm.
During the depressurization, explosions and fires, the radiation exposure on the site rose sharply (see graphic). On March 14th, Tepco considered giving up the power plant and withdrawing all employees because of the excessive radiation risks, but did not receive permission from the Prime Minister. As a result, on March 15, all but around 50 Tepco employees - also referred to in the media as " Fukushima 50 " - as well as 130 other workers and helpers from external companies, the fire service and the armed forces were temporarily evacuated. A few days later, 140 helpers from the Tokyo fire department joined them, who, according to Governor Shintarō Ishihara , were forced to do this by Minister of Economic Affairs Banri Kaieda . Work in the control rooms of the power plant has only been possible to a limited extent since the explosions because the employees were constantly exposed to high levels of radiation and there was only inadequate emergency lighting since the power failure.
Stabilization measures
The decay basins of reactor blocks 3 and 4 as well as the central decay basin were provisionally cooled with water cannons of the Japanese armed forces and the fire department from March 17, 20 and 21 respectively ; Later truck- mounted concrete pumps were used for cooling in units 1, 3 and 4. The fire service pumps for cooling the reactor were also replaced by more powerful devices. Starting from a neighboring high-voltage line, new power lines were laid to the power plant in order to be able to reconnect the electrical systems - if they were still functional - to the power grid. Above all, they hoped to be able to put the cooling systems back into operation. Reactor units 5 and 6 returned to a stable operating condition on March 20 after their emergency power supply had been restored. On the same day, blocks 1 and 2 were reconnected to the power grid, and all other blocks were also connected by March 22nd. The lighting in the control rooms was then restored, but most of the other systems were found to be inoperable or flooded.
The state of reactors 1 and 3 was still unstable at this point in time. In block 3 there was an increase in pressure and unexpected smoke development; the site was once again briefly evacuated. In reactor 1, the cooling caused problems (see here for details ), which continued in April; the activity of the reactor core increased several times. From blocks 2 to 4 steam or smoke rose again and again, from March 25th from all three (as of April 15th). Overpressure, core meltdown and sea water had damaged the pressure and containment vessels of reactors 1 to 3, so that contaminated steam and cooling water were constantly escaping.
From March 25th, the cooling of all reactors and cooling basins was gradually switched from sea to fresh water, above all to avoid further damage from salt deposits. Reactor 1 now held an estimated 26 tons of sea salt, and larger reactors 2 and 3 45 tons each. The freshwater was initially supplied by United States Navy barges, which were pulled or pushed by ships of the Japanese armed forces; It was later taken from a reservoir ten kilometers away via a pipeline .
At the end of March, the Institut de Radioprotection et de Sûreté Nucléaire estimated the heat output of the fuel elements in reactor 1 to be 2.5 megawatts and in reactors 2 and 3 to 4.2 megawatts. This output would be sufficient to allow 95 or 160 tons of water to evaporate per day, and would require continuous cooling with around 150 to 200 tons of water per reactor and day (see the section on quantities of cooling water fed in ). Because of the severely damaged fuel elements in the reactor cores, this water was and is highly radioactive contaminated. Parts of it evaporate and, depending on the weather, can be seen as white vapor clouds over the reactor blocks. The rest will initially remain on the power plant site.
By April 4, 2011, around 60,000 tons of radioactive water had accumulated in this way in the basement of the turbine building, in adjoining shafts and maintenance tunnels running towards the sea, and on other areas. The ground of the site was soaked with radioactive water that it penetrated into the buildings of reactor units 5 and 6, one kilometer away. These masses of radioactive wastewater became an increasing problem. They prevented work on electrical systems that were under water, endangered the workers and ended up in the sea in various ways (→ see Contamination of seawater by the nuclear accidents in Fukushima ).
First safety measures
Various measures to curb radioactive emissions and dispose of waste were discussed early on . This included building a “sarcophagus” like in Chernobyl , covering the reactor blocks with a special fabric , spraying the site with synthetic resin and treating radioactive wastewater with the Russian special ship Landisch ( Suzuran in Japanese ).
The first actually implemented measure was to bind radioactive dusts with synthetic resin. It began on April 6th on small trial areas and was later expanded to an area of half a square kilometer, one seventh of the power plant site. The buildings were also sprayed.
In order to create space for the storage of the contaminated wastewater, Tepco pumped around 10,000 tons of contaminated water from the waste storage facility (approx. 30,000 tons total capacity) with a radioactivity of 150 billion Becquerel (0.15 TBq) from April 4th to 10th Sea. There were protests by Japanese fishermen and the neighboring countries of South Korea, Russia and China. Then they began to pump water from the cellars and tunnels of the turbine buildings into the waste storage and later also into separate tanks, although progress was slow. Tepco commissioned the French nuclear technology group Areva to build a plant that can decontaminate 1,200 tons of wastewater per day on site.
The company Toshiba , the more of the reactors at Fukushima Daiichi had built and also at the disposal work after the accident at Three Mile Iceland was involved, Tepco submitted a bid for safety works at the power plant. Within 10 years Toshiba wants to remove all fuel rods from the power plant site, demolish various plants and reduce the contamination of the soil.
From April 10th, Tepco cleared away the radioactive waste that had been distributed on the power plant site by the explosions of units 1 and 3 with unmanned special vehicles - several dozen cubic meters of rubble per day. This work should continue until summer 2012.
In November 2011, the HAL (robot suit) was selected to carry out clean-up operations on the terrain of the Fukushima nuclear disaster. During the "Japan Robot Week exhibition" (German: "Messe Japanische Roboterwoche") in Tokyo in October 2012, a revised version of HAL was presented, which had been specially developed for the clean-up work in Fukushima.
Further measures served to contain the discharge of sewage into the sea. In addition to sealing manholes and pipes with water glass (see section wastewater discharge into the sea ), Tepco had a steel wall built at the water inlet of reactor block 2 and silt curtains put up at various points. In addition, floating barriers were used to hold back radioactive suspended matter and sandbags were piled up on the south pier of the power plant. Sacks with zeolites deposited at the exit points were supposed to bind radionuclides in the water. The measures were successful: emissions into the sea had fallen to a fraction by the end of April. The measured values on the northern and southern edge of the power plant site (see also the section on radiation exposure at the power plant ) now only showed that the limit values were exceeded slightly.
For temporary protection of the power plant from possible further tsunamis a twelve-meter-high dam was gabions built.
Situation determination
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May brought clarifications to the sequence of the series of accidents and the condition of the power plant. First, the inside of the reactor building was explored. Because of the high levels of radiation in the buildings, this task was performed by PackBot robots that Idaho National Laboratory had converted for this purpose. The approximately one meter high devices could only be used to a limited extent due to the explosive debris in the way, but they provided valuable information about the radiation exposure in various parts of the building. The measured values in block 1 ranged from around 10 to 1000 millisieverts per hour. Various other robot models and remote-controlled special devices were later used, also on the other power plant premises.
Next, the air in the buildings was decontaminated so that workers with appropriate protective equipment could also work there (in some areas). The newly acquired information, together with data records from the control rooms and additional computer-aided analyzes, provided a picture of the condition of reactors 1 to 3. In all three the nuclear fuel rods were largely melted ("melt-down") and the melt had damaged the pressure vessel. The containment was also leaky, which the NISA - which had already confirmed a core meltdown in all three reactors on April 18 - explained that parts of the melt had leaked into the containment ("melt-through"). The cooling water leaked out of the reactors through the leaky container. At the beginning of 2017, a one-square-meter hole was found in the maintenance grille under the pressure vessel of reactor 2, presumably melted by hot material from the fuel elements. It has not yet been possible to determine whether the security container is also damaged.
The entire data material with records of the reactor parameters and activity logs of the employees was published on the Internet on May 16 at the instigation of NISA. Later, NISA also published all reports from the power plant operator to the authorities.
Original plans to quickly stabilize the cooling of the reactors with closed water cycles and to get the release of radioactive substances under control were no longer necessary due to the reactor damage. This also exacerbated the wastewater problem. With provisional measures such as the concreting of manholes and tunnels and the temporary storage of contaminated water in various buildings, which were actually not intended for this and sometimes leaked, Tepco saved itself over time - with the approval of NISA.
In the meantime there were technical problems and incidents, for example a critical temperature rise in reactor 3, a failure of the cooling in block 5 and a power failure in blocks 1 and 2.
The number of people on the power plant site increased steadily. After exceeding 1000 in early May, it was already 2500 in mid-June.
Medium-term stabilization
As a more permanent solution to the wastewater problem, the new decontamination system went into operation in June with four treatment stages:
- Oil separator
- multi-stage cesium filter with zeolites
- Replica of a chemical-physical decontamination system at the La Hague reprocessing plant
- osmotic desalination
The system reduces the radioactivity of the water to a 100,000th and produces highly radioactive sludge, which remains on the power plant site until a decision is made about final disposal . The decontaminated water is partly stored in newly built tanks and partly reused as cooling water for the reactors.
| Week from | metric tons | Plant utilization |
|---|---|---|
| June 29th | 6380 | 76% |
| July 6th | 6130 | 73% |
| July 13th | 4510 | 54% |
| 20th of July | 4870 | 58% |
| July 27th | 6190 | 74% |
| 3rd August | 6720 | 80% |
| August 10 | 7420 | 88% |
At the beginning of June, Tepco estimated the total amount of wastewater that had already accumulated at around 100,000 tons, with a radioactivity of 720,000 terabecquerels - about as much as was released into the air during the "hot phase" of the accidents. The inflow of new wastewater at that time was several hundred tons per day. The decontamination costs were estimated at the equivalent of 1,800 euros per ton.
Instead of the planned 50 tons of flow per hour, the system initially only achieved around 25 to 35 tons. There were regular breakdowns and business interruptions.
A second, more reliable zeolite filter system took over the decontamination of the water that had collected in the sealed off area in front of the power station.
The containment of reactors 1 to 3 was filled with nitrogen in order to prevent possible oxyhydrogen explosions. The cooling basins received new, closed cooling circuits. This allowed the water temperatures to be reduced and corrosive sea salt residues to be filtered out. The concrete pumps went out of service.
The wastewater level in the various buildings remained almost unchanged for months: inflow from cooling water and rain and outflow from treatment and storage in new tanks were balanced. Overflow could be prevented.
In order to increase the processing capacity, the (first) decontamination facility was expanded in August by an additional zeolite filter system built by Toshiba . This made it possible to gradually lower the water levels in the following months. A total of around 130,000 tons of water had been processed by mid-October. Further breakdowns, leaks and downtimes occurred during operation, up to and including the leakage of “at least 45” tons of highly radioactive strontium-contaminated water (175 million Becquerel per liter) in December. Up to 150 liters of it ran into the sea.
Since October 2011, the temperature of all reactors has been below 100 ° C. This state is stable as long as the cooling water supply is not interrupted for more than 18 hours. Japan's new Prime Minister Yoshihiko Noda said on December 16th 2011, the power plant is - as planned - stable shut down ( cold shutdown, cold shutdown ). The NISA had previously confirmed that the cooling was ensured by redundant systems, although Tepco sees a ten times higher risk of failure with the provisional cooling systems than in the normal state. Critics doubt that one can speak of a cold shutdown if the state of the reactor core is unclear.
Long-term coverage
By mid-2013, Tepco had put in an additional steel wall directly in front of the power plant. It was driven deep into the sea floor in order to contain the leakage of contaminated “underground water” for the next 30 years. However, the steel wall does not seem to prevent contamination of the groundwater.
According to the Japanese government, the plan was to remove the fuel assemblies from the spent fuel pools in reactor units 1 to 4 and store them in the remaining spent fuel pools. In 2013, the recovery of around 1,500 fuel rods began. The salvage work in reactor block 4 was completed in 2014. In the other reactor blocks, however, the situation is much more complicated, as rubble first had to be cleared out of the way. The containment of reactors 1 to 3 is to be repaired and filled with water by 2021 and the remains of the reactor cores are to be removed by 2025 . The four blocks are then to be completely torn down. The work should be completed within 30 to 40 years. The evacuation of the fuel from the reactors should be completed by around 2031.
Process in the individual systems
Problems in reactors 1 to 3
After the rapid shutdown of the reactors, the steam and water circuits to the turbines were also interrupted (see lines no. 6 and 7 in the graphic on the right); thus the main heat sink of the reactors was lost as planned. The decay heat absorbed by the evaporating water in the reactors was then dissipated into water-filled condensation chambers, which served as a substitute heat sink. In blocks 2 and 3, this was the large condensation chamber under the reactor (No. 24 in the second graphic), which was cooled indirectly with seawater (RHR system). Various emergency cooling systems were used in the differently structured Block 1.
Less than an hour later, the emergency power generators failed, and with it the electrically operated pumps for the cooling systems of reactor blocks 2 and 3. It was no longer possible to dissipate heat from the reactor condensation chambers and the cooling basins into the sea. The direct cooling of the reactor cores was now carried out with steam-driven pumps (RCIC), whose use is only intended for a limited period of time. A power supply is only required to control the pumps and to control valves. This was possible for a short time in blocks 2 and 3 with emergency batteries until they failed or the cooling system failed for other reasons. In Block 1, the emergency cooling probably already failed due to the tsunami flooding. The diesel-powered pumps of the fire extinguishing system, which could be used as a last emergency measure, could not be used for various reasons or were operated incorrectly. No more fresh cooling water was injected into the reactors and the water still present evaporated. As a result, the water level sank and the reactor fuel rods were initially partially surrounded by water, later not at all, which caused them to heat up further due to the decay heat.
The shells of the fuel rods are made of a zirconium alloy called Zirkalloy . At temperatures above around 800 ° C, the zirconium reacts with the surrounding water vapor to form zirconium oxide and hydrogen . The considerable heat development associated with the oxidation process drives it further ( exothermic reaction ). From around 1200 ° C, the oxidation of the zirconium increases dramatically.
At temperatures above around 900 ° C, the cladding tubes of the fuel rods begin to burst due to the internal gas pressure . This releases radioactive gases and particles of the fuel, including the isotopes 131 I and 129 I, the other fission products 137 Cs , 134 Cs and 90 Sr as well as the brood product 239 Pu . The zircalloy melts above around 1750 ° C, flows together with dissolved uranium oxide from the fuel rods to the bottom of the pressure vessel and is deposited there as so-called corium - a core meltdown has begun. From 2850 ° C, the uranium oxide in the fuel rods also melts and, together with the melted control rods, forms further “corium”. In all three affected reactors, the fuel rods were without cooling for so long that these processes took place and most of the reactor core melted.
Since the reactor pressure vessels were locked after the emergency power failure, the pressure rose to the intended maximum values due to water evaporation and hydrogen production. Safety valves opened automatically and released parts of the steam-hydrogen- radionuclide mixture into the safety containers. Later, the pressure vessels were also manually relieved in order to be able to pump in water.
There was also no longer any possibility of cooling in the security containers, and the pressure there also rose. However, it stabilized at around 750 (reactor 1 and 2) and 500 (reactor 3) kilopascal (see graphic). Presumably at this pressure the seals of the containment failed, so that no higher pressure could build up, but the steam-hydrogen mixture escaped into the reactor building. In order to reduce the pressure and to prevent rupture of the containment portions of remaining in the containment vessels contaminated with radionuclides gases were eventually discharged into the environment ( venting ). It was later suggested that the venting had not worked properly because of undersized pipes or pipes that were broken by the earthquake or because of a lack of power supply, and that this was how the gas got into the building envelope. After most of the pressure relief operations, however, significant radioactive emissions were measured outside the reactor buildings.
After a sufficient amount of hydrogen had accumulated, a hydrogen explosion occurred in each case, which destroyed parts of the building and parts of the technology contained therein. Meanwhile, the meltdowns continued. According to an analysis by NISA, parts of the melted reactor cores ran out of the pressure vessels, accumulated on the bottom of the containment and damaged them.
In order to cool the reactor cores and at the same time prevent an uncontrolled chain reaction , seawater mixed with boric acid was introduced into the pressure vessel. The in natural boron present to 20% isotope 10 B may consist of a nuclear fission produced neutrons absorb very efficient ( neutron absorber ) which is to lithium and helium decays. Since Japan's boron reserves were insufficient, South Korea shipped 52 tons of its boron reserves to Japan. France delivered another 95 tons.
The water was fed in via existing lines, initially with fire fighting equipment and later with more powerful electric pumps. A little more water was introduced than would have been necessary to completely dissipate the decay heat by evaporation, but due to the damage to the containers more than half of it was lost, while the rest evaporated and escaped into the environment. The leakage water partly collected in the containment; the remainder exited from there into the reactor buildings. This emergency cooling process - under more favorable circumstances it would take place without the escape of liquid water - is known as “feed and bleed” . It has the serious disadvantage that radioactive substances from the reactor core get into the environment together with the steam.
Because of the loss of water through the leaks, the remains of the reactor cores could only be partially covered with water, according to NISA; they would be cooled partly with water and partly with steam.
Problems in the cooling pool
An additional risk arose from the fact that the used fuel elements were initially stored in the reactor building and later in a central spent fuel pool for many years and are still being stored. Due to the decay heat, the stored fuel elements continue to give off energy to the pool water, which is dependent on a cooling circuit. Due to the complete power failure, this cooling circuit failed in all cooling pools, so that the water there gradually heated up and partially evaporated.
If the elements are no longer completely covered by water, there is a risk of overheating and chemical reactions similar to those in the reactor, up to and including the bursting of the fuel rods. Without cooling water and without a building roof, which was missing from three of the reactors after the explosions, the radionuclides, which are even in higher concentrations than the reactors, would be released into the environment.
Water readings from the decay basins initially indicated that such processes were taking place in Units 2 and 3, and to a lesser extent also in Unit 4. Later, Tepco and official investigative reports concluded that both the basins themselves and the fuel elements stored in them were highly likely remained intact. During normal operation, the water level in the basin is almost three times as high as the height of the stored fuel elements. This means there is enough reserve to bridge cooling failures lasting several weeks. However, a study published by the National Academy of Sciences in 2016 came to the conclusion that only an accidental leak flooded the cooling pool in Unit 4 and prevented the fuel rods from spontaneously igniting.
Reactor block 1
Unit 1 of Fukushima I was built from 1967 to 1970 and was the first nuclear power plant in Japan. It is based on an older and smaller reactor model than the other units in the plant (→ see technical data for the reactor units ) and had weaker emergency systems. The lifetime of this reactor was supposed to end in early 2011, but was extended by ten years by NISA in February 2011.
Only a relatively small number of old fuel assemblies were stored in the decay basin of Unit 1, which, in contrast to the reactor, required little cooling.
Power and cooling failure
The earthquake triggered a large number of actions in Block 1 on March 11 at 14:46:46 (local time). The reactor was automatically shut down as planned and at the same time switched to emergency power operation due to the failure of the external power supply. Workers later reported broken pipes in the reactor building, from which water gushed out. One of the emergency cooling systems (isolation condenser) switched itself on briefly and then went out of operation again. Another (Containment Cooling System) then initially cooled the containment that surrounds the reactor pressure vessel. Tepco later denied that the earthquake caused significant damage or safety problems, but had to withdraw a similar denial for Unit 3 shortly afterwards.
After the tsunami hit, the emergency generators failed at 3:37 p.m. due to flooding. All running cooling systems went out of service. The reactor data recording also no longer worked, so that only notes and memory logs of the power plant employees as well as theoretical considerations exist for the further process. The backup batteries were only available to a limited extent - if at all - due to the flooding of the electrical system, and the emergency cooling no longer worked, or only worked temporarily, despite several redundant systems. Tepco reported a cooling failure to the supervisory authority at 4:36 p.m. and then again at 5:07 p.m.
The power plant operator ordered emergency generators from other power plants to Fukushima I, but they got stuck in traffic. Then Tepco asked the energy supplier Tōhoku Denryoku for help and had generators come from its power stations; likewise from the armed forces. Replacement batteries were also requested by helicopter from a Tepco power plant in nearby Hirono that was destroyed by the earthquake . In some places they made do with car batteries and mobile generators in order to be able to read at least individual measured values.
Since the cooling failure around 5 p.m., alternative methods of introducing cooling water have also been looked for. Employees went into the dark reactor building, opened valves by hand and started the diesel-powered fire pump . It is unclear to what extent water was actually injected into the reactor. In the control room, the employees tried to use manuals and manufacturer information to find out whether and how the reactor could be depressurized in the event of a power failure.
Due to the events in Unit 1 and other problems at the neighboring Fukushima II nuclear power plant , the Japanese government declared a “nuclear emergency” at 7:03 pm and the local authorities began evacuating the surrounding area. The first mobile power generators arrived at the power plant two hours later, but could not be connected because of blocked access routes and cables that were too short.
Pressure rise, core meltdown and cooling attempt
The water in the reactor continued to evaporate and the water level fell, but due to the lack of data recording it is unclear when and how the steam escaped from the pressure vessel into the containment. Individual measurement data from the following night indicate that sooner or later this happened due to a leak in the pressure vessel or the pipelines connected to it.
The partially dry fuel elements overheated and the above-described decomposition processes began. According to later investigations, a core meltdown began around 7 p.m. to 8 p.m. The water level meter was decalibrated due to overheating . During a check at 9:19 p.m. it indicated that the reactor core was still fully covered with water. The cooling by fire pump seemed to work.
From 21 pm, the authorities allowed a computer simulation to estimate that radioactive releases at a pressure relief ( venting ) of the containment, ie when releasing steam into the environment would result. The time of venting was assumed to be 3:30 a.m. on March 12th. The system predicted that the onshore contamination would be confined to the power plant site and that the northwest wind would carry the "radioactive cloud" out to sea.
At around 1 a.m. on March 12, the pressure in the containment exceeded the maximum permissible pressure of 528 kPa by 600 kilopascals (kPa) (in each case absolute; the relative pressures to the external atmosphere are around 100 kPa lower). A few hours later it reached 840 kilopascals (kPa), but then dropped back to 750 kPa on its own. Presumably the steam escaped past the overloaded seals of the containment into the reactor building, together with the hydrogen produced in the overheated reactor core. A slight increase in radiation ( local dose rate ) was detected for the first time at a measuring station on the western edge of the site . Radiation also increased in the turbine building in Unit 1. None of those responsible was aware that hydrogen was accumulating outside the containment.
The fire pump had run out of fuel. It was not possible to put it back into operation; it was ineffective anyway at high reactor pressure.
An emergency meeting was held in the Prime Minister's office. According to government circles, Tepco was urged to relieve the pressure on the containment of reactor 1, while the power plant operator himself said it asked for permission to relieve the pressure. Either way, venting was not easily possible because the electrically and pneumatically operated valves were out of order.
The radiation at the boundary rose rapidly and was at 4:35 a.m. with 0.00038 to 0.00059 millisieverts per hour (mSv / h) at 10 to 15 times the normal value. Meanwhile 40 TEPCO workers began to manually lay a 200 meter long and one tonne power cable from the generator car to a connection point at Block 1/2.
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From 5:46 am, pumps from the fire engine stationed at Block 1/2 were used to inject fresh water from existing extinguishing water cisterns into the pressure vessel in order to cool the reactor as necessary; Hydrants and the much larger pure water tanks were unusable due to tsunami damage. The high reactor pressure limited the water flow. An hour later, the Ministry of Economic Affairs instructed Tepco to manually open the pressure relief valves. The radiation measured at the boundary had meanwhile increased tenfold.
At around 7 a.m., Prime Minister Naoto Kan arrived at the power plant by helicopter - according to official statements to signal support from the population in the region, but according to newspaper information, however, to influence crisis management. Kan asked Tepco to form a "suicide squad" of workers who were supposed to undertake the manual pressure relief. There was radiation of around 300 mSv / h in the building, a level that is dangerous to the health of people even if they stay for a short time.
Critics later suspected that the depressurization of reactor 1 had been delayed by Kan's presence. At around 8 a.m. - immediately before Kan's departure - the power plant manager gave the instruction to prepare manual venting for 9 a.m.
Depressurization and explosion
At 9:03 a.m., the authorities reported that the evacuation of the city of Ōkuma , on whose territory reactor units 1 to 4 are located, had been completed. Immediately afterwards, workers equipped with protective suits, compressed air bottles and flashlights went into the reactor building. Using a portable power generator, they managed to open the first (electromotive) pressure relief valve a quarter. They gave up trying to open the second pneumatic valve on the containment because of excessive radiation.
From 10:17 a.m. onwards, attempts were made several times to operate the pneumatic valve from the control room. The sensors in the containment did not show any significant pressure drop (see graphic), but the radiation at the edge of the site temporarily increased from 0.007 to 0.39 mSv / h. At the same time, Tepco tried to find a portable compressor in order to open a more easily accessible, larger pneumatic valve elsewhere.
Around noon, the defective water level gauges indicated that the fuel rods in the reactor core were half dry, and NISA warned that a core meltdown might have started.
At around 2 p.m., the workers managed to open the second pneumatic valve using a compressor. Tepco reported at 2:30 p.m. that the pressure relief had been successful. At 2:49 p.m., radioactive cesium was detected in the vicinity of Block 1. At 3:01 p.m. the hourly updated Tepco webcam showed steam escaping from the chimney at Block 1/2 for the first time, and at 3:29 p.m. the radiation at the site boundary exceeded the permitted limit of 0.5 at 1.0 mSv / h mSv / h.
By 2:50 p.m. the fresh water supplies were exhausted. According to its own information, Tepco had made preparations to quickly switch from fresh to seawater discharge; it could have started at 3:18 p.m. However, this was delayed by several hours due to communication problems between the power plant operator, supervisory authority, government agencies and the Prime Minister and / or due to technical concerns of the Prime Minister. (A NISA report later stated that there was “no hesitation” in using seawater.) The heavy power cable was now connected to the distributor in Block 1/2.
At around 3:30 p.m., workers tried to power a pump to feed borated water into the reactor (SLC pump). At this moment, an oxyhydrogen explosion (hydrogen explosion) occurred between the containment and the outer shell of the reactor building , during which the upper part of the outer lining of the reactor block was blown away. Video recordings show a fast, barely visible explosion burst upwards and then a cloud of smoke that spreads more horizontally than vertically around the reactor building. The explosion injured four workers on site, cut the power line, which was only completed half an hour ago, and damaged prepared hoses for discharging seawater. The backup work was interrupted for two hours.
At the time of the explosion, there was a southeast wind at the power plant. A mobile radiation measuring station on the northwestern, landside boundary showed a sudden, short increase from 140 to 1015 millisieverts per hour at 3:29 p.m.
The government announced that the reactor's containment had not been damaged. Later she was surprised: no one would have informed her beforehand that the venting could result in an explosion of the reactor building. Tepco pointed out that the hydrogen is normally broken down in the containment; Nobody expected an explosion.
The Japanese authorities suspected a core meltdown from around 5 p.m. due to the increased cesium values . The authorities prepared the distribution of iodine tablets and extended the evacuation radius around the power plant to 20 kilometers.
In the meantime, all measuring instruments for the reactor condition (pressure, temperature, water level) in Block 1 had failed. Apparently the emergency batteries were now completely exhausted.
Cooling tests and power connection
At 7:04 p.m., Tepco began introducing seawater into the reactor and informed NISA. However, since no confirmation was received from the Prime Minister, Tepco decided to stop pumping water around 7:30 p.m. The manager of the power plant ignored the instruction and continued the makeshift reactor cooling. An official clearance by the Prime Minister and NISA did not take place until around 8 p.m. It was later said that the Ministry of Economic Affairs had given the permit around 6 p.m.
From 8:45 p.m., the neutron-absorbing boric acid was added to the cooling water to reduce the risk of criticality. At 10:15 p.m. the sea water cooling had to be interrupted for a few hours due to an aftershock . The amount of water fed in fluctuated between 2 and 20 cubic meters per hour in the following days.
On March 13th the mobile generators finally succeeded in establishing an emergency power supply. The gauges again provided information on the status of the reactor, but the cooling systems remained out of order.
Over the next few days and weeks, the defective water level gauges continued to show that half of the fuel elements (or their remains) were covered with water. Apparently it had been possible to stabilize the water level via the fire extinguishing pipe. Every now and then the water supply had to be interrupted again for a few hours because the area was evacuated due to critical situations at reactor block 3 , due to further earthquakes or to repair minor defects in the pumping system.
It was now largely agreed that a core meltdown was taking place in Unit 1; Government spokesman Yukio Edano also officially confirmed this. Based on the radiation readings in the reactor of Unit 1 on March 15 (see section Radiation in the reactors ), Tepco estimated that 70 percent of the fuel rods were already damaged. Six weeks later, this figure was then corrected down to 55 percent - still based on the measurements from March 15 - because it was initially miscalculated. Another two and a half weeks later it was assumed that 100 percent of the fuel rods were damaged.
The makeshift cooling did not succeed in stabilizing the reactor core. On the morning of March 16, large amounts of steam escaped from the reactor building, while the radiation on the premises (see graphic ) rose sharply. In the following days the activity in reactor 1 (see also section Radiation in the reactors ) increased again. The temperature at the pressure vessel temporarily reached a maximum of 383 ° C on March 22nd, above the maximum planned operating temperature of 300 ° C.
On March 20, Block 1 was reconnected to the external power supply via a new power distributor (the old one was under water in the basement of the turbine house), and the lighting in the control room was restored on March 24. The majority of the electrical systems remained without function.
Only on March 23, Tepco switched the water feed into the pressure vessel to a different access line ( feed water - instead of fire extinguishing / core spray line) and more powerful pumps, so that the amount of water could be increased from 50 to 170 cubic meters per day . This, too, was apparently not enough to get the reactor under control: the radiation readings from the pressure vessel rose again to a new high by April 1st. Salt deposits may have restricted the flow of cooling water.
On March 31, for the first time since the power failure, the cooling pool in Block 1 was also cooled: A truck- mounted concrete pump sprayed 90 tons of water on it. It is unclear how much of the water was in the pool, but later research has shown that the water level never fell into a critical range.
Another unstable reactor
- April 2011
In April, reactor 1 seemed to be the only one that remained unstable: the measuring devices showed a steady and uncontrolled increase in pressure in the pressure vessel throughout April (see graphic; it was only two months later that it was discovered that the pressure sensors were also defective and displayed too much) . The reactor core presumably continued to produce hydrogen. After consultation with the Ministry of Economic Affairs, Tepco filled the containment with nitrogen to prevent a possible oxyhydrogen explosion.
On April 8, the radiation sensor in the pressure vessel of block 1 showed an extreme increase; the following day he fell out . Two weeks later, the ratio of 131 I and 137 Cs concentrations in the seawater channel of the adjacent and structurally connected Block 2 rose sharply.
On April 21, the Kyodo News reported that, according to a Tepco official, reactor 1 could (again or still) be undergoing a meltdown.
The power plant operator was concerned that the situation could get out of control if the makeshift cooling were to be unplanned and wanted to increase the amount of water fed in in order to fill the safety and pressure vessels with the excess water and thereby cool the reactor more reliably. In addition, a new, more stable and closed cooling circuit should be installed.
- May 2011
In preparation for the planned work - Tepco published a roadmap for this - the air in the building was decontaminated with special air filter devices . The water level gauges for the pressure vessel were then recalibrated and it was found that the area of the reactor core in which the fuel elements had been located before the melt was not about half under water, but not at all. Apparently, both the pressure vessel and the containment vessel were damaged and significant amounts of cooling water leaked from the reactor. The planned new cooling measures became obsolete due to the leaky safety container. The basement of the reactor building, in which the condensation chamber is located, was half filled with an estimated 5,000 tons of radioactive waste water.
The meltdown report on April 21 was not confirmed. It was now assumed that the remains of the reactor core were partly in the pressure vessel and partly in the containment and were cooled there.
Protection of block 1
- from June 2011
The cooling of the cooling pool was switched from a concrete pump to a direct line at the end of May and to a closed circuit in August. From the end of June, recovered wastewater was used to cool the reactor, so that an indirect cooling circuit was created to replace the closed cooling system that was no longer feasible.
As a hedge against radioactive emissions and rainwater entering a protective cover was built around the reactor building, consisting of a steel frame, PVC -coated polyester fabric - Plan and an elaborate ventilation system (completed in October 2011). The roof of the envelope can be opened if necessary.
On August 19, 2011, the reactor temperature in Unit 1 fell below 100 ° C for the first time on all sensors.
High hydrogen concentrations of 61 to 63 percent were discovered in pipes on the reactor. Presumably they were leftovers from the initial phase of the accidents. The hydrogen was driven off by pumping in nitrogen.
New Tepco simulation calculations in November showed that the majority of the molten fuel in reactor 1 had left the pressure vessel and had accumulated on the bottom of the containment (No. 13 in the picture above ). The concrete floor could be eroded up to 65 centimeters deep. A concrete layer of at least 37 centimeters would remain between the fuel and the steel casing of the containment (No. 19). Underneath there is another layer of concrete several meters thick (No. 20). It is assumed that the cooling measures carried out stopped further corrosion of the concrete.
Reactor block 2
Power failure and cooling problems
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Block 2 was also automatically shut down on March 11 at 2:46 p.m. (local time) and initially supplied with emergency power from its two diesel generators. In order to refill water that evaporates in the reactor, the workers in the control room switched on one of two steam-operated emergency cooling systems (the RCIC system, Reactor Core Isolation Cooling; for example: "Cooling the reactor in isolated operation").
At 3:37 p.m. and 3:41 p.m., the generators failed due to flooding, and so did the electrical cooling water pumps for the cooling pool and the reactor condensation chamber. Parts of the battery emergency power supply also failed due to tsunami damage.
At 16:36, Tepco reported to the supervisory authority that the water injection into the reactor - i.e. the emergency cooling - was no longer ensured. The steam-driven cooling system was independent of the generators, but because of the power failure, the RCIC status display and the measuring device for the cooling water level had failed. On March 12th they were put back into operation with a temporary power supply. The water level was a little lower, but stable. The pressures in the reactor were in the normal range. Nevertheless, several pressure relievers were attempted around noon, which were unsuccessful due to the lack of overpressure. Meanwhile, the roof of the neighboring reactor building 1 to the north exploded.
This was followed by changing messages on the Tepco website about the state of the cooling. At 8 p.m. it supposedly stopped working; on the morning of March 13th at 9 a.m. it was said that the RCIC system was in operation. The later published records of the employees are also contradictory. There were still problems with measuring the water level. To be on the safe side, Tepco prepared the feed of seawater.
At 11 a.m., the containment was again relieved of pressure. Between 2 p.m. and 5 p.m. the pressure in the containment dropped a little. Around 2 p.m., mobile power generators were also connected, so that, according to NISA, the continued operation of the emergency cooling system was ensured.
On March 14, at 11 a.m., the neighboring reactor building 3 to the south also exploded and damaged the equipment for pumping seawater into reactor 2. Immediately after the explosion, the blow out panel of reactor building 2 was opened to prevent hydrogen accumulation as in the Blocks 1 and 3 to prevent. Around this time, the cooling system actually failed in Block 2. The extraordinarily violent explosion in Block 3 may have caused further damage in Block 2. At 1:18 p.m. - the water level in the reactor pressure vessel had already fallen by about one meter, but was still above the fuel elements - Tepco reported the cooling failure to the supervisory authority. The second steam-powered emergency cooling system, which is normally activated in such cases, remained switched off.
The introduction of seawater was prepared again, but had to be interrupted from 3 p.m. to 4 p.m. due to an aftershock. The fire service pump was ready for use at around 4:30 p.m., but the pressure in the pressure vessel first had to be reduced. The workers brought car batteries from their vehicles to the control room and tried to use them to operate the pressure relief valves. However, they could not be opened because an airflow meter was accidentally switched off. Tepco tried unsuccessfully for several hours to let off steam from the pressure vessel in order to then vent the safety vessel as well.
The water level kept falling. Around 5 p.m. the fuel elements were partially exposed and from 6 p.m. completely. At this point the pressure relief valves finally opened. It took an hour to release the pressure enough. In the meantime, the fire pump, which was not constantly monitored due to the high level of radiation on the premises, ran out of fuel. Almost another hour passed before the water injection could begin - too late: the meltdown was already underway at this point. Despite further attempts to relieve pressure - the pneumatic venting valve kept closing on its own - the pressure in the containment rose sharply and reached around 750 kilopascals around midnight .
The water level measuring device indicated now and in the coming days and weeks that half of the fuel elements were covered with water. Only two months later - after calibrating the measuring device in block 1 - it became clear that the device in block 2 (and 3) could have displayed too much the whole time. Similar to March 12 in Block 1 , the containment seals presumably failed and hydrogen got into the reactor building.
Damage to the containment
According to reports published later by NISA and JAIF , around midnight (March 15), steam was released from the containment into the area. However, the sensor showed no pressure drop. It remained at 750 kPa until around 6:10 am a loud bang could be heard from the direction of the condensation chamber under the reactor (" an abnormal noise began emanating from the nearby Pressure Suppression Chamber " according to Tepco). The NISA spoke of an "explosion sound" and a hydrogen explosion in the space below the reactor in which the condensation chamber is located; later also of a “big, impulsive sound” and a “ big impact sound”. The pressure in the chamber suddenly dropped; apparently it was damaged. Damage was also found in the roof area of the reactor building and in the adjacent waste processing building. Tepco has so far denied that an explosion took place and suspects that it was confused with the approximately simultaneous explosion in Block 4 (as of November 2011).
The radiation exposure on the site rose sharply, which may also be related to the explosion in Block 4. Dose rates of up to 12 millisieverts per hour (mSv / h) were temporarily measured at the site boundary. At the reactor building 4 the measured values were 100 mSv / h and at the neighboring block 3 they were 400 mSv / h. Because of the radiation risks, Tepco reduced the number of employees on the site from around 800 to 50.
At 10:30 am, Minister of Economics Banri Kaieda Tepco instructed to immediately inject water into the pressure vessel of reactor 2 and to release the pressure from the containment. After the containment 2 vented by itself in the meantime and the water had been fed in for 14 hours, this instruction came too late.
In the evening, the overpressure in the pressure vessel fell to zero, which indicates greater damage.
Satellite photos from March 16 show steam escaping from the exhaust flap on the east side of the reactor building. This could also be observed in the following days.
Based on the radiation readings in the containment, Tepco estimated that one third of the fuel rods from Unit 2 were damaged. That estimate later turned out to be way too low.
By March 17, the damage to the condensation chamber also spread; the overpressure in the chamber also fell to zero.
Three weeks later, information from the US Atomic Energy Agency emerged that pieces of the molten core of Reactor 2 had flowed out of the pressure vessel and had accumulated in the bottom of the containment. Radiation data from the condensation chambers in units 1 to 3 (in the lower area of the containment) confirmed this: the measured value for unit 2 was extremely high at 121 sieverts per hour.
Power connection and cooling measures
In the meantime, a new high-voltage line was in the works, which was to be connected to Block 2 first. It was hoped that the regular cooling systems could be put back into operation.
Meanwhile, on March 19, seawater began to be fed into the cooling pool. In contrast to Unit 1, the decay basin also had to be continuously cooled in Unit 2 because it contained twice as many and “fresher” fuel elements. At intervals of several days, the basin was refilled with cold water via an existing pipe. It was thus possible to stabilize the water temperature at around 50 ° C. The water level never fell into a critical range.
Also on March 19, the new power line was connected to a makeshift transformer in Block 2, and the next day to a temporary, new power distributor. From March 26th there was again a real lighting in the control center. A photo released on the same day shows three men in protective suits looking at individual instruments - in a room full of dead screens and warning lights. The power supply was restored, but as in Block 1, most of the systems remained inoperative.
From March 26, freshwater was injected into reactor 2 instead of seawater. In the basement of the turbine building of Block 2, Tepco measured a very high radiation of more than 1000 mSv / h on the surface of water that had collected there (1000 mSv / h was the upper limit of the existing measuring devices). The following day, similar radiation values were also discovered in the water in an attached maintenance tunnel. As a result, the Japanese government announced on March 28 that it was assuming a temporary partial core meltdown in reactor 2.
On March 29, the cooling of the cooling basin was switched from sea to fresh water.
Sewage discharge into the sea
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- April 2011
Since March 21st, strongly increased iodine and cesium concentrations in the seawater at the power plant were measured and the cause was sought.
On April 2, Tepco discovered a 20 centimeter long crack in a concrete cable duct near the water inlet of Block 2, from which highly radioactively contaminated water flowed into the Pacific. An attempt to close the leak with concrete failed, as did the introduction of a mixture of superabsorbent , sawdust and shredded newspaper into connecting pipes to the turbine building. On April 6, Tepco was able to close the leak with a water-glass- based sealant .
According to NISA, most of the contaminated water had been released in the two days after the condensation chamber was damaged on March 15, but smaller amounts of water continued to flow out of the reactor, from where it entered the sea through various channels and shafts ( see grafic). Only later did it become clear that the pressure vessel was possibly also damaged and that large amounts of wastewater were continuously leaking from there.
On April 9, Tepco began building a steel wall and building a silt fence in front of the water inlet of Unit 2 to protect the sea from further contamination.
A week later, the first measured values for the water in the cooling pool were available. They showed a high level of radioactive contamination (see table of measured water values in the cooling basin ), which was most likely caused by emissions from the reactor.
Extremely highly contaminated water had also collected in the basement of the turbine building of Unit 2, a total of 25,000 cubic meters. Tepco began to pump 10 cubic meters per hour into the waste storage facility, while the ongoing cooling measures of the reactor and the cooling basin were constantly generating new wastewater. The water level in the turbine building remained almost unchanged. The further leakage of the extremely contaminated water from Unit 2 into the sea could, however, be largely stopped by the sealing and containment measures .
- May 2011
After the radiation in the condensation chamber below the reactor had decreased by the beginning of May, it temporarily increased fourfold from May 3rd . The molten core was still moving.
Protection from block 2
Further work in the reactor building was hardly possible due to excessive radiation exposure, and a humidity of almost 100 percent prevented the use of decontamination devices. The cooling pool was therefore given a new, closed cooling circuit that lowered the water temperature from 70 to 40 ° C and helped to reduce the humidity. The building was then ventilated and the air further decontaminated. Measuring devices on the reactor were calibrated . An investigation revealed that the highly radioactive wastewater was six meters high in the basement.
- from June 2011
At the end of June, the introduction of nitrogen into the containment began in Block 2 in order to prevent possible oxyhydrogen explosions.
In order to improve the reactor cooling, the cooling water was also introduced via the core spray system from mid-September . The water is sprayed from above into the pressure vessel and over the reactor core instead of pumping it in from the side, as is the case with all other cooling systems.
In early November, cesium was filtered in the cooling pool in order to reduce the extremely high level of water contamination.
On March 27, 2012, endoscopic examinations of the containment revealed that the water level was only 60 cm instead of the expected three meters due to leaks. However, the water temperature is 48.5–50 ° C. The radiation in the partially destroyed containment is between 30 and 73 Sv per hour.
In February 2017, a camera could be brought directly under the pressure vessel for the first time. Here it was confirmed that the reactor has melted completely and may have eaten its way through the containment. In addition, extreme radiation doses of 530 Sv / h were measured.
Reactor block 3
At the time of the accident, in contrast to Units 1 and 2, reactor block 3 was also equipped with 32 mixed oxide fuel elements (out of a total of 548 fuel elements), which contain a mixture of uranium dioxide and plutonium dioxide . Plutonium is poisonous and, due to its radiation effect, is highly carcinogenic even in small quantities. There were only conventional uranium fuel elements in the spent fuel.
Power and cooling failure in block 3
Block 3 was also shut down quickly on March 11 at 14:46 due to the earthquake, and the RCIC emergency cooling system (Reactor Core Isolation Cooling System) took over the water injection into the reactor as scheduled. After the arrival of the tsunami, the two emergency generators and the electric cooling water pumps for the cooling pool and the reactor condensation chamber failed at 15:38 and 15:39. The steam-powered RCIC system continued to run independently of this, in contrast to Block 2, however, only at half power. The backup batteries remained intact.
Around midnight the emergency cooling no longer worked properly; the water level fell below the intended range. On March 12th around 11:30 am the RCIC system failed, and an hour later the HPCI system ( High Pressure Coolant Injection ) switched on automatically . This is a much more powerful, steam-powered emergency cooling system that is used when the RCIC system is insufficient or fails. There was a sharp drop in pressure in the pressure vessel, which indicated earthquake damage to the HPCI pipes.
The supervisory authority (NISA) announced at a press conference around 6 p.m. that the water level in the reactor had fallen and that something urgently needed to be done about it. Around 9 p.m., preparations began to let off steam from the containment. (Initial NISA reports erroneously stated that the pressure was relieved at 8:41 p.m.)
On March 13 at 2:44 a.m., the HPCI emergency cooling failed because the batteries were exhausted or the reactor pressure was too low. Tepco tried unsuccessfully to get the RCIC system back into operation. At 5:10 a.m., the complete failure of the cooling was reported to the supervisory authority. At this point the pressure in both containers had risen sharply again. An attempt to inject water with the stationary diesel fire extinguishing pump of the reactor therefore failed.
After all the car batteries available in the power plant had already been used to rescue units 1 and 2, Tepco took batteries from vehicles at the government operations center and operated the safety valves on the pressure vessel of reactor 3 from the control center. The safety container valves - similar to block 1 - opened manually. Around 8:50 a.m., the pressure in the pressure vessel fell from approximately 7350 to 500 kilopascals (kPa), while in the containment it rose from 470 to 640 kPa and then fell again.
The hourly updated Tepco webcam showed steam escaping from the chimney of block 3/4 at 10:00.
Makeshift cooling of the reactor
At 9:08 a.m., makeshift cooling also began for reactor 3 by injecting water through the fire extinguishing pipe. The fire engine normally stationed at Block 5/6 was used for this. First, fresh water was fed in from the cistern of the fire extinguishing system and then switched to sea water mixed with boric acid. The measuring devices nevertheless indicated that the water level was still falling. NISA suspected that the measurement display was incorrect, as other readings indicated a functioning water supply, while government spokesman Edano mentioned technical problems with pumping in. The 3.70 meter long fuel rods were now probably dry for a good 3 meters and were very hot. Edano announced that a core meltdown in Block 3 is expected and that a hydrogen explosion is also possible here. Later research confirmed that a core meltdown began around this time.
After the pneumatic pressure relief valve closed by itself, it was opened again manually with a compressor around noon. At 1 p.m. and 2 p.m. the webcam showed steam escaping from the pressure relief chimney of block 3/4. This venting operation was repeated several times later.
On the night of March 14th, the water injection into the reactor had to be interrupted due to a lack of seawater in the sump. According to NISA, the interruption took place between 1:10 and 3:20 a.m. However, the water level displayed for the pressure vessel only began to drop shortly after 3 a.m., while the pressure in the pressure and safety vessel rose at the same time. The fuel assemblies were probably three meters long again at around 6 a.m., so that the meltdown could proceed.
At 5:20 am, according to later NISA reports, steam was released again; Radiation readings from the site tend to indicate venting between 2 and 5 a.m. However, the pressure in the containment increased steadily and reached around 500 kilopascals (kPa) around 7 a.m. From this point on, a rising water level in the pressure vessel was displayed again. The water level indicator then stabilized to such an extent that the fuel elements were probably 40 percent covered. The pressure remained at about 500 kPa for the next few hours.
Armed Forces tank trucks delivered 35 tons of fresh water that morning and began pouring it into the water sump for reactor cooling.
explosion
At 11:01 a.m., a violent explosion occurred in the reactor building. Video recordings show a ball of fire in the upper area and a dark mushroom of smoke rising quickly and vertically upwards. According to Tepco, seven people were injured in the explosion. The Daily Telegraph reported that six Japanese Central Nuclear Biological Chemical Weapon Defense Unit employees were killed , but the report remained unconfirmed, even after the debris was later cleared.
In contrast to Block 1, the explosion not only destroyed the roof area, but also parts of the floor below. Radioactive debris was hurled onto the site at distances of up to one and a half kilometers. Hot spots with local dose rates of up to 1000 millisieverts per hour arose around block 3 . In the neighboring block 2, the cooling system or its power supply was presumably damaged , which led to a core meltdown there with far-reaching consequences, including contamination of the sea. There was an oil fire in Unit 3, which caused further serious damage to the reactor building.
The American nuclear engineer Arnold Gundersen pointed out the much greater force and the stronger vertical direction of the Block 3 explosion compared to the hydrogen explosion in Block 1. Gundersen suspected that the explosion in Unit 3 was based on a criticality incident, i.e. a nuclear explosion in the decay basin, which was triggered by a smaller hydrogen explosion in the reactor building.
The makeshift cooling of reactor 3 had to be interrupted until the evening because the explosion had damaged the fire fighting equipment. The water pit with the freshly delivered fresh water was also unusable due to debris that had fallen in.
On March 15 at 10:22 a.m., radiation of 400 millisieverts per hour (mSv / h) was measured at Block 3. Based on radiation readings in the reactor, Tepco estimated that the fuel rods in reactor 3 were damaged by a quarter. That number was later revised up to 30 percent.
Large amounts of steam have been observed rising from the building since the morning of March 16 and on the days that followed. A local dose rate of 400 mSv / h was still measured at reactor block 3. After 10 a.m., the radiation value at the boundary of the site rose to up to 10 mSv / h (at the same time, large amounts of steam also escaped from Block 1). It was feared that the containment would be damaged and the joint control center of Blocks 3 and 4 was cleared between 10:45 and 11:30. The water injection into the pressure vessel was interrupted for this time.
Further manual depressurization took place from March 15 to March 20.
Makeshift cooling of the cooling pool
In addition to the reactor core, the fuel elements also had to be cooled in the cooling pool in the upper area of the reactor building. There was a risk that the explosion had caused leaks and that the fuel assemblies overheated and caught fire due to a lack of cooling water. The existing pumps could not be used, however, due to a lack of power supply or due to explosion damage. Instead, they resorted to seemingly desperate means: Chinook helicopters of the armed forces were supposed to throw water from the air. The first attempt on the evening of March 16, however, was canceled due to the high risk of radiation for the pilots.
The next morning they made a second attempt. This time, the helicopters were shielded from below with lead plates and dropped four water charges of 7.5 tons each from extinguishing water tanks onto the reactor building as they flew past. Video recordings show that the drop was not very accurate and that a large part of the water fell next to the reactor block or was already evaporating in the air. Instead of the planned dropping of several dozen water charges, the attempt was canceled.
The New York Times was of the opinion that the helicopter drops were primarily a demonstration of the ability to act for the Japanese people and the United States. Prime Minister Naoto Kan then phoned US President Barack Obama personally and told him about the alleged success of the campaign.
After the failure from the air, the next attempt was made from the ground: A water cannon from the riot police and five special fire engines from the Japanese armed forces sprayed a total of around 30 tons of water on or into the reactor building. Tepco rated the attempt as a success: Steam had risen, so you hit the cooling pool. Therefore, the cooling with fire trucks of the armed forces continued in the following days.
From March 20, fourteen fire engines from the Hyper Rescue Unit of the Tokyo Fire Department also took part in the operation. The amount of water sprayed increased to several hundred tons a day in the following days.
Hazardous situations and cooling measures
On March 20, the pressure in reactor 3 rose again. Temporarily, almost 500 kilopascals were reached in the containment - allegedly so “little” that it was not necessary to let off contaminated steam again. In later reports, however, the (last) opening of the pneumatic pressure relief valve is mentioned at around 11:25 a.m.
From the following day at 4 p.m. gray smoke was observed rising from the remains of the reactor building. Tepco temporarily withdrew its employees from the power plant site. The cooling operation with fire trucks and the work on the power supply at Block 3 were interrupted. The radiation at the western boundary of the area increased tenfold to 2 millisieverts per hour. From 6 p.m. the intensity of the smoke subsided, but some of it was still visible in the following days.
On March 22nd, Block 3 was the first to have its power restored; The control room now had proper lighting again. Two days later, Tepco posted a photo showing working overhead lights, but dark monitors and dead warning lights. In between there is a piece of paper with the inscription "SBO 3/11 15 ° 39 '", which could stand for " station blackout (power failure) on March 11th at 3:39 pm".
On March 23rd and 24th, seawater was discharged into the cooling pool via the regular cooling system.
On March 24th, two workers who had laid power lines in the basement of the turbine building of Block 3 were exposed to high levels of radiation exposure to their feet, with suspected radiation burns. Investigations revealed that highly radioactive water had accumulated in the building. According to information from NISA, this was apparently water from the reactor core. NISA spokesman Hidehiko Nishiyama said the containment was believed to be damaged, but withdrew the statement the same day. The cause of the water leak is unclear. Part of the water was then pumped into a tank further up.
From March 25th, the cooling of the reactor pressure vessel was switched to fresh water. The water spraying of the cooling pool was carried out on that day by the Kawasaki fire brigade , with the support of colleagues from Tokyo. Two days later the water cannons had had their day; Instead, a truck-mounted concrete pump was used, which the Tepco employees christened "Elephant" because of its long metal trunk, and later "Giraffe". From March 29th, fresh water was sprayed instead of sea water.
At the end of March, the supervisory authority assumed that the reactor's pressure vessel was leaking. Presumably, gases would escape from the container through tired valves, pipe connections or seals.
On April 12th, the spray arm of the concrete pump was fitted with a camera. After observing the water level, Tepco ruled out significant leaks in the pool. Further calculations showed that the water level never threatened to fall into a critical range. The risky helicopter and water cannon operations would therefore not have been necessary, and the theory of a nuclear explosion in the fountain would no longer be tenable.
On April 26th, Tepco switched the water feed into the cooling pool again. Now a regular injection line was used again (the fuel pool coolant clean-up system ).
Unstable reactor and contaminated water
The activity of reactor 3 had steadily decreased since mid-March. At the end of April , Tepco reduced the amount of water fed into the reactor a little. As a result, the temperature at the pressure vessel began to rise sharply (see graphic). Tepco reacted with a 30 percent higher amount of cooling water, which stopped the temperature rise in some places on the pressure vessel, while other places continued to heat up. The power plant operator suspected that some of the cooling water did not reach the reactor at all, but rather disappeared through a branching pipe, and doubled the amount of water with the help of another access pipe. That got the situation under control; the reactor temperature fell back into uncritical ranges.
In Unit 3, too, very high radionuclide concentrations were found in the water of the cooling basin . The 131 iodine concentration was too high for stored fuel elements. Tepco explained this with the fact that substances leaked from the reactor during the explosion on March 14th were hurled into the fountain. Since the basin is completely covered with rubble, the condition of the fuel assemblies cannot yet be checked (status: end of 2011).
On May 11th, Tepco found that in Block 3 - as before in Block 2 - highly contaminated water was flowing from a cable duct into the sea, apparently only for a few days. The leak was closed with textile material and concrete, but readings indicated further sewage leakage into the sea. An attempt was made to remove the inflow from the leaks by pumping water out of the turbine building, but after a week there was not enough space left in the waste storage facility. Until the wastewater decontamination system was put into operation in the second half of June, other temporary measures such as pumping into a condensation water tank in the turbine house were managed.
On the night of June 13-14, the Tepco webcam showed a violent burst of steam from Block 3.
Protection of block 3
From the end of May, Tepco, together with the cooling water, also introduced hydrazine into the fouling basin as a corrosion protection agent. In June a new, closed cooling system was installed and boric acid mixed water was introduced. The pH of the water in the cooling pool had risen to 11.2, presumably due to the dissolution of concrete rubble, and the alkaline water threatened to destroy the aluminum fuel element storage racks.
At the beginning of July the reactor building was decontaminated in order to subsequently (from mid-July 2011) introduce nitrogen into the containment. A robot cleared away radioactive debris.
In order to further improve the reactor cooling, Tepco began introducing water via the core spray system at the beginning of September 2011 .
Damage to block 3
In July 2017, a swimming reconnaissance robot managed to penetrate the reactor for the first time and deliver usable images. At a depth of six meters there is a cold layer of slag up to one meter thick, which experts believe is probably corium , a mixture made up of molten metal parts, the crumbling shells of fuel rods and the nuclear fuel itself.
Reactor block 4
Reactor block 4 has been out of operation since November 29, 2010 due to repair work on the shell of the reactor pressure vessel. Therefore, at the time of the quake, there were no fuel elements inside the reactor . Instead, these were stored in the cooling pool inside the reactor building, 97 percent of which was used. Since the fuel assemblies were only in use relatively recently, they produced a particularly large amount of decay heat .
One of the two emergency power generators and parts of the reactor data recording were also out of order due to maintenance work.
Cooling failure, explosion and fires
One of the remaining emergency power generators failed due to flooding, and with it the cooling of the cooling pool; the water temperature rose. By March 14th it reached 84 ° C; then the temperature measurement system failed. As the basin continued to heat up, the cooling water probably began to boil and evaporate; In addition, there was fear of water loss due to building damage and leaks after the explosion in Unit 3. There was a risk that the fuel elements were partially exposed and heated up to the point where hydrogen could be released.
On March 15, around 6 a.m., an explosion occurred in the reactor building of Block 4, which destroyed most of the upper two floors and other outer walls. Observers like the IAEA explained this with the fact that hydrogen was produced in the decay basin and exploded as oxyhydrogen. Later, Tepco and NISA came to the conclusion that hydrogen probably got from Block 3 through connected ventilation pipes to Block 4 and exploded there. This was supported by video recordings that showed intact fuel elements in the spent fuel, water analyzes and particularly large damage in the area of the ventilation pipes.
After the explosion, black clouds of smoke drifted west from Block 4 for several hours. At 9:38 a.m., a fire was reported on the third floor of the reactor building. According to the IAEA, there was a fire in the cooling pool; however, an oil fire is more likely. The radiation on the site temporarily rose sharply and reached a record value of 12 mSv / h at the site boundary, which may also be related to the presumed explosion in Block 2 , which was approximately at the same time .
When a team from the United States Army and the plant fire department approached at around 11 a.m., the fire had already gone out by itself.
The American nuclear regulatory authority NRC described the situation of block 4 as the most critical of all blocks. There was speculation in the media about a possible criticality accident in the decay basin, which contained over 200 tons of fuel elements. If the nuclear chain reaction starts again, this can lead to an extensive release of radioactive material. The NRC estimated that in the worst case scenario, radiation could have killed 200,000 people. Nuclear energy expert Arnold Gundersen said Japan had been split in half. There would have been a 50-kilometer-wide strip across Japan, so that people would no longer have come from north to south. Tepco denies major damage to the cooling pool and points to the functioning cooling.
On the evening of March 15, the Minister of Economic Affairs instructed the power plant operator to discharge water into the sink. He announced that it was not yet possible to discharge water into the cooling pool. According to press reports, the access roads to Block 4 were blocked, and a new access was still in progress.
In the late evening, the radiation on the site rose sharply again. On the following day at 5:45 a.m., a fire was observed again in Block 4, but it was no longer detectable at 6:15 a.m. In a satellite photo taken shortly afterwards, large parts of the shell of the reactor building are missing. High-resolution photos published later show different degrees of damage depending on the side of the building and the floor.
Temporary and random cooling of the cooling pool
Since the spent fuel pools could not be cooled from the ground and the water-bombing helicopter was unsuccessful, the further attempts concentrated water cannons on the smoking block 3. Therefore, there was a dispute between the chairman of the US Nuclear Regulatory NRC , Gregory Jaczko , and Tepco. Jaczko said there was no more water in the cooling pool of Block 4, while Tepco claimed that water was turned off during the helicopter flyby. US experts discussed possible leaks. Three months later, the NRC admitted that Jaczko was wrong. In March 2013, however, the engineer Atsufumi Yoshizawa from Tepco, who had been a member of the emergency services on site, stated in a newspaper interview that the fission pool with the fuel rods had dried up at the time and that there was a risk of a possible nuclear fission reaction. A study published by the National Academy of Sciences in May 2016 confirmed that only an accidental leak to the adjacent flood chamber had caused a renewed influx of water and prevented a catastrophic fire in the fuel rods.
On March 20, at 8:21 a.m., water began to be injected into the cooling pool at Block 4 with the help of fire engines from the armed forces. From March 22nd, a truck- mounted concrete pump built in Germany was used instead of fire trucks to spray around 150 tons of water onto the basin every day.
From March 27th, the cooling pool was no longer cooled daily, but with water from the concrete pump every several days. On March 30th there was a change from sea to fresh water.
- April 2011
First water analyzes from the decaying basin published on April 13th showed unusual concentrations of 131 I, 134 Cs and 137 Cs (see table of measured water values of the decaying basins ), which can be explained by slight damage to the stored fuel elements. However, the entry of radioactive emissions from units 1 to 3 is more likely. In addition to taking samples, the water temperature was also measured. It was 90 ° C, well above the normal high of 40 ° C. By this time, a total of 1,800 tons of water had been sprayed onto reactor block 4.
In order to lower the temperature, more water was introduced and thus the water level (above the fuel elements) increased. Tepco then became concerned about the stability of the basin because the concrete structure of the reactor building had been weakened by one of the explosions in March, and reduced the water level again. Again, this was insufficient for cooling; therefore it was switched to an automatic, temperature-dependent control.
Observations of the water level and further investigations showed that there was probably no significant leak and that the fuel elements were completely covered with water at all times.
- from May 2011
From mid-May, Tepco also injected hydrazine into the cooling pool as a corrosion protection agent together with the cooling water . Concrete- coated sprouts were inserted under the basin for stabilization.
At the end of July, the commissioning of a new cooling circuit for the cooling pool began.
Reactor blocks 5 and 6
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Units 5 and 6 were out of service during the earthquake due to maintenance work, but were again equipped with nuclear fuel rods. In block 5, pressure tests were just taking place on the reactor pressure vessel .
Continuous cooling was and is required for both the reactor cores and the cooling pools in the reactor buildings. Block 6 is based on a newer, differently structured reactor model than the other Fukushima I blocks (see also: data on the reactor blocks ).
Of a total of five emergency generators in blocks 5 and 6, one in block 6 survived the tsunami. Nevertheless, the cooling of the reactors and cooling tanks failed in both blocks because the tsunami - as in blocks 1 to 4 - had destroyed the seawater pumps. The pressure vessels were depressurized in both reactors; In block 5, the valves had to be opened manually due to the lack of power. The nitrogen feed into the containment of reactor 5 failed and was restored manually.
Initially, nothing was publicly known about these problems. It was not until March 15 that government spokesman Edano informed him that the cooling system was not working properly in Block 5 and 6 either. At this point in time, the emergency cooling systems for both reactors had already begun using the generator from Unit 6. The reactor cooling was thus ensured. The water levels were in a safe area, two to two and a half meters above the reactor core.
In contrast, the cooling basins initially remained uncooled. By March 15, the water temperatures there had already risen from the normal range from below 40 ° C to around 60 ° C. On March 19, they reached maximum values of around 67 ° C (see also: table of temperatures in the cooling basins of units 5 and 6 ).
On March 18, workers climbed onto the roofs of the two reactor buildings and, as a precaution, drilled three 3.5 to 7 centimeter ventilation holes in each of the concrete ceilings in order to reduce the risk of oxyhydrogen explosions.
On March 19, provisional replacement seawater pumps went into operation at both blocks, which were also supplied with power from the remaining diesel generator from block 6. This enabled the regular cooling for the reactors and cooling pools to be restored. The water temperature in both cooling pools fell below 40 ° C the next day and then leveled off between 20 and 40 ° C. On March 20, both units returned to the stable, shutdown "cold, subcritical" operating state (cold shutdown) for the first time since the start of the incidents , after the water temperatures in the reactors had also returned to normal.
On March 21, the power supply of Block 5 was switched from emergency to mains power, and Block 6 followed on March 22nd.
From April 4, Tepco pumped radioactively contaminated seepage water that had accumulated in the drainage shafts of units 5 and 6 into the sea . Water had already run into the buildings through the overfilled drainage. Following protests from neighboring countries, the discharge of contaminated water into the sea was stopped on April 10th, and from May onwards, water was regularly pumped out of the basement of the turbine house of Block 6 into temporary tanks. From there, in July, the water was moved further into a 10,000 cubic meter floating tank on the sea. Parts of it were later decontaminated, desalinated and, from October 2011, sprayed on the power plant site.
Central cooling pool
The central cooling pool is located in a separate building next to the reactor building 4 and also requires a power supply for cooling. Here, too, there were problems after the complete power failure: Despite temporary attempts by Tepco to cool the pool with water cannons, the temperature rose from around 30 ° C on March 11 to 55 ° C on March 18, 2011 to 73 ° C on March 24th. After the power supply was restored on March 24th, the temperature sank below 40 ° C by March 27, continued to fall in the following days and leveled off again around 30 ° C.
An analysis of the water in the basin on May 14, 2011 revealed increased cesium concentrations .
Assessment of health risks
A review published in 2015 brought together estimates of morbidity and mortality from six publications. The estimates are all based on the LNT model . Stanford University researchers (Ten Hoeve & Jacobson, 2012) estimated the global health impacts to be 130 (15-1100 as lower and upper uncertainty values) cancer-related deaths and 180 (24-1800) cancer-related diseases, 90% of them in Japan. In addition, up to 600 deaths occurred as a result of the evacuation. Evangeliou et al. (2014) estimated the number of cancer cases to be 230-850 and the number of cancer-related deaths to be 120-650. Together with 610 cases caused by exposure to workers and forced evacuations, this would result in a total of 730-1260 deaths. Aliyu et al. (2015) summarize existing studies without arriving at a defined result.
According to the UNSCEAR report from 2013, no radiation-related deaths or acute illnesses have been observed up to this point. The radiation doses received by the population were generally low to very low, and an increase in radiation-related diseases was not expected. For twelve workers who were exposed to very high levels of radiation (thyroid doses of 2 to 12 Gy), an increased risk of thyroid cancer and disorders can be expected. For 160 other workers who received doses above 100 mSv, an increased risk of cancer can be expected, although a determination is very difficult due to statistical fluctuations. In 2011, a large-scale survey of the local population (Fukushima Health Management Survey) began, covering over 30 years the more than 2 million people who were living in Fukushima Prefecture at the time of the accident. This includes thyroid examinations of 360,000 children (up to 18 years of age). The first round of investigations found an increased rate of nodules, cysts and cancer cases, but this was expected based on the measurement method used. The use of the measurement method in other areas not affected by the accident also resulted in a larger number of findings, indicating that a possible increase in Fukushima Prefecture is not related to radiation. In 2015, UNSCEAR published a white paper in which they evaluated the 80 studies that have appeared since the 2013 report. Accordingly, none of these studies change the key conclusions of the 2013 report.
In 2013, the World Health Organization (WHO) published a study assessing the health risks posed by the accident. According to the study, no increased cancer rates are to be expected outside of the most affected areas. Deterministic radiation damage is not to be expected, since the radiation doses in the Fukushima prefecture were well below critical values. The radiation doses are also too low to negatively affect pregnancies. In the two most affected places in the prefecture - assuming that the affected people ate exclusively on locally produced food (including food that exceeded the limit values) and that they were only relocated after 4 months - doses of 12 to 25 mSv were estimated . In the hardest hit location, pessimistic estimates using the LNT model show an increase in the relative risk of developing cancer as follows:
- + 7% leukemia: men exposed to stress in the first year of life
- + 6% breast cancer: women exposed to stress in the first year of life
- + 4% Solid tumors: women exposed to stress in the first year of life
- + 70% thyroid cancer: women exposed in the first year of life (since the basic risk of developing thyroid cancer is 0.75%, the absolute risk increase for this population is half a percentage point)
In the second most affected location, these risks are halved. There are also lower risks for people who are stressed in childhood or adulthood. In less affected areas in the prefecture, the risks decrease to a quarter or a third of the risks in the most affected area. In addition to cancer, other thyroid disorders could also arise for emergency workers who have inhaled large amounts of radioactive iodine.
In addition, the number of mental disorders among the evacuees increased significantly. Studies have shown that the number of mental illnesses among the evacuees rose to 15%, and 70% of the evacuees reported sleep disorders. Compared to the Japanese average (3% mental illness, 15% sleep disorders), these values were increased by a factor of 5. In addition, obesity and diabetes rates also increased significantly among the evacuees . Among evacuated seniors, death rates increased threefold in the first three months after evacuation compared to before the disaster; later they fell 1.5 times.
Employees in the power plant
A total of around 25,000 workers were deployed to deal with the disaster by October 2013. The radiation exposure of these workers was corrected upwards by around 20% in a UN report in October 2013. The reason for this was that many of the approximately 25,000 workers were examined with a time delay, so that in particular the radiation exposure of the short-lived iodine isotopes could no longer be recorded. The reports issued by Tepco and the Japanese authorities did not take this into account.
Radiation exposure
According to information from the Tagesschau , at least 20 workers were "irradiated" by March 16. As later became known, a woman also received a radiation dose of around 18 millisieverts (mSv), with a limit value for women of 5 mSv per three-month period. The limit for male power plant workers in emergency situations was raised on March 15 from 100 to 250 mSv per year.
On March 24, three workers laying power lines in the basement of the turbine building of reactor block 3 ignored the alarm from their dosimeters and received radiation levels of 170 to 180 millisieverts. Although Tepco knew that there was highly radioactive water at a similar location in Block 1, the workers were not warned. Two of them did not wear protective boots - the work regulations of the responsible external company did not provide for this - and received local radiation doses of 2 to 3 Sieverts on their feet. An investigation found that no medical treatment was necessary; a follow-up examination on April 11 by the Japanese National Institute of Radiological Sciences was inconclusive.
According to Tepco, 80 of its own employees and 19 employees of external companies were exposed to radiation and contamination with an equivalent of over 100 mSv from March 11 to 31, 14 of them between 150 and 200 mSv, 4 between 200 and 250 mSv and 6 over 250 mSv. These numbers are incomplete because the dosimeter reading did not work in the first three days after the power failure and because there was a temporary lack of dosimeters. Tepco stated the average external exposure of several thousand tested workers to be 13.7 mSv; an average of 8.9 mSv is calculated for the internal exposure. This internal exposure is understood as the long-term radiation dose from the radionuclides absorbed by the body. A significant part of this was due to the high 131 I load in March at short notice.
In two of the highly exposed workers, 131 I-activities in the thyroid gland of 7690 and 9760 Becquerel, respectively, were found. The resulting internal radiation exposure was 540 and 590 mSv, respectively, and the total doses were 643 and 678 mSv, respectively. During the first three days of the accident, both had been working in the joint control center of units 3 and 4 and had not taken any iodine tablets .
According to Tepco, there have been no more exposure over 100 mSv since April and no exposure over 50 mSv since August (as of October 2011).
Non-nuclear accidents
According to NISA, five employees were slightly injured in the earthquake. Another broke both legs and one suffered a heart attack. Two people were missing after the quake and found dead three weeks later in the basement of a turbine house.
The explosion of reactor building 1 on March 12th and the smoke that resulted slightly injured four people, according to NISA. Another employee suffered a stroke that day.
According to NISA, eleven people, including four members of the armed forces, were slightly injured by the explosion in reactor block 3 on the day after next. A report by the Daily Telegraph that six employees of the Japanese Central Nuclear Biological Chemical Weapon Defense Unit were buried under the rubble in the explosion remained unconfirmed.
In the following period, the NISA reported various, mostly minor injuries and illnesses associated with visits to the doctor or hospital: Several workers became uncomfortable under the respirators, one stumbled and injured his knee, and one suffered an eye injury from leaking cooling water on one Concrete pump and another injured when falling from a ladder.
On May 14, a 60-year-old worker passed out while carrying materials in the waste disposal building. There was no radioactive contamination; the doctors suspected a heart attack.
People outside the power plant
According to a report in the Mainichi Daily News , 90 bedridden, comatose or otherwise dependent patients were left behind at Futaba Hospital in Ōkuma during the March 12 evacuation . Half of them - mostly older people - died before, during or after the delayed evacuation from March 15. According to a documentation by the Japanese broadcaster NHK, a total of 50 bedridden patients in the hospital died.
The media reported on suicides believed to be related to the evacuation or the economic consequences of the disaster.
- Long-term effects from radiation
If additional doses of radiation are consumed, the statistical risk of developing cancer increases . In initial estimates, scientists assumed there would be around 100 to 1000 additional cancer cases as a result of the nuclear accidents in the long term. This corresponds to a 0.01 to 0.1 percent increased risk of cancer in the contaminated areas. These numbers may be too small to be statistically proven.
On the USS Ronald Reagan , which had been assigned to an aid mission in the region and later decontaminated as a result of radiation exposure, crew members had been diagnosed with 71 serious illnesses by the end of 2013, including 51 cancer cases. Since the Fukushima nuclear disaster is believed to be the cause of the illnesses, the crew members filed a lawsuit against Tepco. In 2020, the lawsuit was dismissed by the 9th US Circuit Court of Appeals.
In Fukushima prefecture total 103 cases were from since the accident until March 2015 Schilddrüsenkrebsen registered in children. This type of cancer is specific to nuclear power accidents because the radioactive iodine-131 released in the acute phase accumulates mainly in the thyroid gland, which is still small in children, and thus damages them. However, a connection between individual radiation exposure and an increased risk of developing thyroid cancer could not be established. The increase in the number of cases is therefore attributed to improved examination methods (screening effect).
Contaminations
Due to the pressure relief and makeshift cooling of the reactors and the overheating of the cooling basins, there was a massive release of radioactive material into the atmosphere in the first days of the series of accidents (→ see also: Overall estimates of the release into the atmosphere ). The exposure to radioactive particles and gases had an impact on the wider area and on the rescue work after the earthquake. Areas with particularly high levels of radioactivity were evacuated .
The radioactive fallout contaminated agricultural products in Fukushima and Ibaraki prefectures up to a multiple of the legal limit, which is why the Japanese Ministry of Health imposed sales and consumption bans on a number of foods.
Warnings were also given against drinking highly contaminated tap water. In Tokyo, 250 kilometers away, tap water pollution temporarily exceeded the 131 I limit values for small children.
While the radiation exposure in the Japanese prefecture of Fukushima decreased again in the second half of March, the European Union declared a "radiological emergency". This replaced the normal limit values for radioactively contaminated food with higher values that were set for such situations after the Chernobyl nuclear disaster . Two weeks later, the EU is lowering the limit values for Japanese imports again.
In April, the sea was heavily polluted by radioactive substances, partly by particles from the air, but above all by radioactive waste water that was created by the ongoing cooling of the reactors and decay basins and that flowed into the sea through drains and shafts (→ see also: Overall estimates of pollutant release into the sea ).
Near the power plant, the legal limit values for radioactive iodine and cesium in seawater were temporarily exceeded by 50,000 to 200,000 times . Slightly exceeding the limit values for 131 I were detected at distances of up to 30 kilometers from the power plant, and for radioactive cesium in up to 15 kilometers. The fishing had to be partially stopped. With various measures , the emission of pollutants was then reduced to a fraction in the second half of April. The 131 I concentration in the water near the power plant was below the legal limit from the end of April, the 134 Cs and 137 Cs concentrations from the beginning of June. The pollutants that had already leaked, however, accumulated to an alarming extent in algae and on the sea floor .
The radioactive substances released mainly during the first few weeks of the accident caused further contamination in the Fukushima prefecture and the surrounding area. In the period from May to July 2011, limit values were exceeded in tea leaves and bamboo shoots , in cattle feed and beef. Parts of it had already been put on the market and sold. Experts assume that agriculture will be impossible for decades in the particularly badly affected areas in the east and northeast. Increased radioactivity was also measured in tens of thousands of tons of sewage sludge and several hundred tons of ash from waste incineration plants ; disposal posed logistical problems for Japan.
The emissions of 134 Cs and 137 Cs, in particular, continue, in several million times less than during the first week of the accident (as of August 2011; see total emissions from the nuclear accidents in Fukushima ). Plutonium was also found within a radius of 45 kilometers. The radiation exposure within the 100 km zone is roughly 1000 times the amount measured in the 1963 atomic bomb tests . Since August 2011, Tepco has not been able to detect any significant radioactivity in the sea in front of the power plant.
On June 19, 2013, Tepco admitted that the groundwater near the turbine building of reactor 2 had high levels of the radioactive substances strontium 90 and tritium . The values for strontium 90 would be more than thirty times the maximum permissible value; Tritium was found in eight times higher concentration than permissible.
According to Tepco announcement of July 9, 2013, the cesium-134 load rose to 9000 Becquerel per liter. The permissible limit is 60 Becquerel.
In August 2013 it became known that radioactively contaminated water had been flowing into the sea for two years, at that time around 300 tons per day. Tepco first admitted this in July 2013, after the nuclear supervisory authority had previously expressed the suspicion that highly radioactively contaminated water was flowing into the ground and sea. The reason for this are leaks in the system, through which approx. 400 tons of groundwater seep into the system every day, plus the deliberately introduced cooling water. In order to prevent the contaminated water from flowing out in the future, a barrier is to be built, which should be completed in October 2015 [obsolete] . The costs for this are borne by the Japanese state.
Also in August 2013, the leakage of at least 300 tons of highly contaminated reactor cooling water from a leaky collecting container was reported. This resulted in a "large amount of radioactive material escaping within the facility". This leak was rated independently of the rating of the destruction of the facility (“catastrophic accident” (level 7)) as level 3 (“serious incident”) on the seven-point INES scale . While the radiation exposure was originally given as 100 millisieverts per hour, Tepco announced on August 31, 2013 that the values on the tank reached around 1.8 Sieverts per hour, a dose that is fatal after 4 hours. The reason for the late discovery of the high level of exposure was that radiation measuring devices had previously been used with a scale only reaching 100 millisievert. Therefore, the high radiation was only noticed when new measuring devices were used that can record values of up to 10,000 millisieverts. In addition, significantly increased radiation levels and another leak from which contaminated water drips were found in other tanks.
In May 2017 it became known that the radiation exposure within the destroyed power plant blocks is sometimes so high that there are also problems with radiation-hardened robots. These fail very quickly because they are built for a radiation exposure of approx. 70 Sievert, but 530 Sieverts per hour were measured in the reactor building.
Classifications on the INES scale
The seven-level international assessment scale for nuclear incidents (INES) is used to inform the public about the safety-related significance of nuclear incidents.
The Japanese nuclear regulatory authority (NISA) initially classified the incidents in reactor block 1 on March 12 at level 4 ("accident"). On March 18, it increased the classification for block 1 to level 5 ("serious accident"), selected level 5 for blocks 2 and 3 and classified the incidents in block 4 provisionally as level 3 ("serious incident").
The US Institute for Science and International Security (ISIS) assigned the accident sequence to level 6 (“serious accident”) on March 15. The physicist Helmut Hirsch commissioned by the environmental protection organization Greenpeace came a week later, based on the first, rough estimates of the radioactive emissions by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) and the Central Institute for Meteorology and Geodynamics (ZAMG) to a classification in the maximum level 7 ("Catastrophic Accident"), as high as the Chernobyl nuclear disaster .
On April 12, 2011, NISA published its own estimate of the total amount of radioactive material released, which was approximately one tenth of the amount released by Chernobyl. Based on this estimate, it now classified the accidents in reactor units 1 to 3 as “temporarily” level 7. It later corrected its estimate of emissions several times without affecting the INES classification (→ overview of emissions estimates ).
NISA assessed the processes in the individual reactor blocks according to the criteria of the INES user manual from 2008 as follows:
| criteria | Maximum possible level |
Classification block 1, 2 and 3 |
Classification block 4 |
Classification block 5 and 6 |
|---|---|---|---|---|
| 1. People and the environment | 7th | Level 7 | not yet determined | - |
| 2. Radiation barriers and facility control | 5 | Level 5 | not yet determined | - |
| 3. Tiered security levels | 3 | level 3 | level 3 | - |
| Overall rating (provisional) | 7th | Level 7 | level 3 | - |
She has not yet set the second criterion for Block 4 (as of April 12, 2011), as the incident has not yet been concluded. It did not assign an INES rating to blocks 5 and 6. The overall rating results from the highest individual rating in each case.
The accidents in Fukushima were beyond design basis incidents , that is to say “super-GAUs”.
Protective measures for the population
Alerting
The Japanese Atomic Energy Agency ( Nuclear and Industrial Safety Agency, NISA) was immediately after the outbreak of the earthquake on 11 March 2011 at 14:46 (local time) by the operator informed about the situation. After arrival of the tsunami and failure of emergency generators Tepco announced at 15:42 for the first time a nuclear emergency (Nuclear Emergency) in the nuclear power plant Fukushima I. After further reports arrived about emergency situations from other nuclear power plants, the Japanese government declared on March 11 at 19:03 Watch the State of Nuclear Emergency .
On March 12 at 5:00 p.m. - one and a half hours after the first explosion - Tepco reported an unusual increase in radiation at the site boundary. In the next few days, numerous other reports of reportable incidents followed.
evacuation
Local population
- March 2011
At 8:50 p.m. on March 11, the Fukushima Prefecture Emergency Operations Center ordered the evacuation of the population within a two-kilometer radius of reactor block 1 after the cooling system failed there. The Prime Minister later had this radius gradually increased to three (March 11 at 9:23 pm), ten (March 12 at 5:44) and 20 (March 12 at 6:25 pm) kilometers. By March 13, around 62,000 of the 78,000 affected people had been evacuated.
Another 62,000 residents in areas 20 to 30 kilometers from the power plant should initially stay in their homes at 11:00 a.m. on March 15, according to the Prime Minister's instructions. On March 25, the government advised them to voluntarily leave the area; the reason she gave was supply bottlenecks.
In the emergency shelters, which were also used to accommodate those affected by the tsunami, people were turned away from the contamination zone, partly for fear of radiation. Doctors had to issue clearance certificates.
From March 19, the city council and the entire population of Futaba , in whose urban area the reactor units 5 and 6 are located, were relocated to Saitama , where they were housed in the Saitama Super Arena , and on 30/31. March finally around 1300 including the city administration to Kazo . Hirono moved to Ono by early April . The relocation of other places was ordered: Katsurao to Aizubange , Kawauchi and Tomioka to Kōriyama and Namie to Nihonmatsu , Naraha to Aizumisato , and Ōkuma , to which the power plant units 1 to 4 belong, to Aizu-Wakamatsu . With the exception of Saitama, all destinations are in the west or north of Fukushima Prefecture.
On March 28, government spokesman Edano confirmed that the 20-kilometer evacuation zone should be maintained. Local authorities have been instructed to prohibit entry to the area.
Various sides considered the evacuation radius to be insufficient. Gregory Jaczko, chairman of the US regulatory agency Nuclear Regulatory Commission , recommended an extension to 80 kilometers; 1.9 million people would be affected. On March 27th, Greenpeace called on the Japanese government to immediately evacuate children and pregnant women in particular from a radius of up to 60 kilometers. In the 7,000-inhabitant village of Iitate , around 40 kilometers northwest of the power plant, observers from IAEA and Greenpeace measured particularly high levels of contamination and radiation exposure. Greenpeace then asked the Japanese authorities to extend the evacuation to Iitate, while the IAEA advised that the situation be examined. Authorities indicated they were already considering evacuating Iitate.
When the evacuation zone was set on March 12, the Japanese government assumed a maximum radiation exposure of 50 millisieverts per year (mSv / a); this corresponds to an average of 0.0057 millisieverts per hour (mSv / h). With expected values between 10 and 50 mSv / a, residents should not leave their houses.
- April 2011
At the beginning of April, the NISA advised the government to evacuate from a possible exposure of 20 mSv / a. For comparison: The world average natural radiation values are 2.4 mSv / a.
On April 12, the government decided to evacuate Katsurao, Namie and Iitate, as well as parts of Kawamata and Minamisōma outside the 20-kilometer zone , because the annual dose there was estimated to be 20 mSv or more. The estimate for Namie was 300 mSv. The residents had to leave the towns by the end of May.
In mid-April, Prime Minister Naoto Kan was quoted as saying that the evacuation zone around the power plant could remain uninhabitable for ten to twenty years. Kan denied this. Shortly afterwards, Tepco published a plan to begin decontamination work in the evacuation zone during the second half of 2011 to allow residents to return. The government later announced that it would not decide on a possible return of residents until 2012.
After residents repeatedly returned to the 20-kilometer zone despite the dangers of radiation, the government declared this a restricted area from April 22nd . One person per household was allowed to return briefly if their home was more than 3 kilometers away from the power station; in addition, entry into the area was prohibited. 27,000 households in nine municipalities are affected by this regulation. Violators were threatened with fines of up to 100,000 yen (around 840 euros at the time) or short prison sentences. 75 checkpoints were set up along the access roads.
For the zone 20 to 30 kilometers away from the power station, a flexible regulation was introduced on April 22, in which, depending on the location, it is decided whether the residents should stay in their apartments or be evacuated.
- June – August 2011
Further observations and measurements revealed hot spots with radiation exposure over 20 mSv / a in various not yet evacuated places and districts of the Fukushima prefecture. Date's city council recommended 113 households move to less polluted locations; 72 households in Minamisōma were affected and 60 in Kawauchi. Households with an evacuation recommendation receive financial support from the state; the recommendations are based on radiation measurements in the garden and at the entrance to the houses. As a result, residents who have tried to decontaminate their property have less chance of financial help.
- September 2011
After reactors 1 to 3 had reached a relatively stable state with temperatures below 100 ° C, the Japanese government lifted the conditional evacuation zone at a distance of 20 to 30 kilometers from the power plant at the end of September. At the same time, Fukushima Prefecture withdrew the evacuation order for Minamisōma, Tamura, Kawauchi, Hirono and parts of Naraha.
The police reported a sharp increase in the number of burglaries in the exclusion zone. 720 cases have been reported since the series of accidents began; in the same period last year there were only 27.
- since 2012
Prime Minister Shinzō Abe announced [obsolete] to lift evacuation orders by March 2017 . After two smaller areas, Naraha finally followed on September 4, 2015 as the first community in Fukushima prefecture.
Nationals of other states
- March 2011
On March 12, the German Foreign Office and the Austrian Federal Ministry for European and International Affairs issued partial travel warnings for northeast Japan, Germany also for the Tokyo area . The Austrian embassy relocated its operational area to Osaka on March 16, the German embassy on March 17.
In mid-March, various states such as Russia, Belgium, the Philippines and the United States provided planes to evacuate government employees and other citizens.
The USA, Australia and South Korea recommended their citizens to keep a distance of at least 80 km from the damaged power plant. The United States and Thailand also recommended that their citizens leave the country.
On March 17, France asked its citizens in Tokyo to leave Japan or to go to the south of the country.
- April 2011
The US doctor Robert Peter Gale , who coordinated medical aid in Chernobyl on behalf of the Soviet government in 1986, criticized individual evacuation recommendations and - literally - "panic reactions" by individual states. Fear of it is more harmful than the radiation itself. According to Gale, the consequences of the exodus of foreigners from Japan would be devastating. Therefore, the German reaction to Fukushima should not only be determined by emotions and a panic reaction, but should be as considerate and thoughtful as possible.
On April 12, the Philippine government ordered the repatriation of all of its citizens from within 50 kilometers of Fukushima I. Only Filipinos married to Japanese were allowed to stay in Japan if they wished.
On April 15, the USA once again confirmed their 80-kilometer ban zone around the power plant, but withdrew their general travel recommendation. Russia withdrew its travel warning on April 19.
At the end of April, the German embassy returned to Tokyo.
air traffic
On March 12, 2011, the Japanese government imposed an air exclusion zone for a radius of 20 kilometers around the power plant, which was expanded to 30 kilometers on March 13.
The German Lufthansa had all aircraft returning from Japan tested for radioactivity from March 14th. From March 15 to 23, 2011, it redirected its flights destined for Tokyo-Narita to Nagoya and Osaka .
The Austrian Lufthansa subsidiary Austrian Airlines continued to fly to Tokyo accompanied by military radiation protection experts. In contrast to the normal regular service, however, the stays were only kept briefly and the crew changes were carried out in Seoul . The Swiss moved its crew move to Hong Kong .
Food bans and warnings in Japan
Import and export bans for food
On March 24, 2011, the European Union ordered compulsory controls for food produced after March 11 from twelve prefectures in Japan. Since March 27th, they can only be imported into the EU countries if they have been tested for radioactivity in Japan and the test results have been certified in writing. The Japanese information should be checked randomly.
Russia, China, Taiwan, Australia and the USA imposed import bans on certain foods from four or five Japanese prefectures affected by excessive radiation levels and tested imports for radioactivity. South Korea also initially adopted such a ban, but lifted it on March 24th after the Japanese government for its part banned the export of certain foods from Fukushima Prefecture . On April 14, South Korea imposed another import ban on all food from 13 of the 47 Japanese prefectures .
On April 6, Russia banned the import of Japanese fish.
decontamination
For the decontamination of the power plant site, see first safety measures .
The city of Kōriyama , with a population of 340,000 , 60 kilometers west of the power station, began removing the contaminated surface of the soil in schools and kindergartens at the end of April, and the city of Fukushima at the end of May. The government advised the cities that simply digging up the soil could be enough.
In Minamisōma, decontamination began in August.
In December, task forces of the Japanese armed forces decontaminated administration buildings and their vicinity in the evacuated locations of Naraha, Tomioka, Namia and Iitate with high-pressure cleaners .
Long-term prospects
In November 2013, representatives of the Japanese government stated that a full resettlement of the population evacuated from the Fukushima region (approx. 150,000 people) would probably not be possible. The government would have to designate areas in which human settlement would be impossible in the long term due to the high radiation exposure. The evacuated affected persons would have to be compensated.
Criticism of the crisis management
See also: Criticism of risky technology and lack of maintenance of the power plant in the article Fukushima Daiichi nuclear power plant
Press reports on the initial phase of the nuclear crisis paint a picture of employees, decision-makers and scientific advisors who were overwhelmed by the situation. Several “worst-case scenarios” happened at the same time and had to be handled. The decisions taken or not taken and the information policy of the responsible bodies have been criticized many times. Various sides thought the Japanese crisis management was too indecisive. The IAEA criticized the structure of the responsible government agencies as being too complicated and slow to react.
All measures that could affect the population had to be approved by the government in accordance with legal requirements.
A report submitted by a parliamentary commission of inquiry at the beginning of July 2012 speaks of the mess and sloppiness of the operating company, the government and the nuclear regulatory authority. The “human disaster” was predictable and avoidable. Katsutaka Idogawa, the mayor of Futaba , complained in an interview with the Russian television station RT in April 2014 that he had been left alone with the situation.
Conflicts
The press also reported conflicts between those responsible. According to reports from the Yomiuri Shimbun , Prime Minister Naoto Kan, government spokesman Yukio Edano, Defense Minister Toshimi Kitazawa and other members of the government were frustrated and increasingly suspicious of Tepco's lack of or constantly changing explanations about what was going on at the power plant. Kan in particular is said to have developed a great deal of distrust both towards Tepco and towards the nuclear supervisory authority (NISA) and the higher-level Ministry of Economics (METI). According to press reports, civil rights activist Kan fundamentally distrusted the Japanese bureaucracy , which was intertwined with industry, and thereby cut himself off from important sources of information. Instead, he relied on personal advisors who were also poorly informed.
On March 15, Kan appeared furious at the Tepco company headquarters and reprimanded the Tepco managers present because of their information policy and Tepco's plans to “withdraw all personnel from the Fukushima Daiichi nuclear facility and stop the rescue work.” He had a joint crisis team there Set up government and power plant operators to have more influence on crisis management. An expert from the US nuclear regulatory agency visited the Tepco headquarters three days later and was irritated by the chaos of expertise. The management of the crisis team and gradually also the entire nuclear crisis management took over Kan's close confidante Goshi Hosono .
Conversely, Tepco representatives were frustrated with the Prime Minister because he listened more to his personal advisers than to the responsible authorities. An employee of the Tepco crisis team in Fukushima was quoted as saying that he felt more pressure from the prime minister than from his own superiors. According to Tetsunari Iida , chairman of an institute for sustainable energies and energy policy advisor to the Japanese government, the qualified physicist Kan overestimated his own competence in nuclear technology . He wanted to have a say in too many technical details and intimidated the Tepco managers with his presence. At the same time, Iida criticized the company's decision-making structures. For every decision, the experts on site would have to obtain permission from the company headquarters, in which both the government (via the crisis team) and managers who are not used to making independent decisions have a say. The " time " attributed the latter to a consensus orientation typical of Japan, which prevents quick decisions.
A number of contradictions between the information published by Tepco and NISA on the course of the accident make it clear that there were also communication problems between the power plant operator and the supervisory authority (see documentation of processes and publications in the article Chronicle of the Fukushima Nuclear Disaster ). The IAEA indicated that technical competence in NISA could be improved.
Coping with the technical problems
Various sides were of the opinion that Tepco had hesitated too long before releasing the pressure in the reactors and discharging seawater. By bringing these measures forward, the accidents could have been prevented or at least their effects reduced.
The Yomiuri Shimbun related the delay in these important decisions to the absence of Tepco President Tsunehisa Katsumata and Chairman Masataka Shimizu . The two company managers did not arrive until March 12 to 16 and 10 am in the company and were only accessible by until then mobile phone involved. Technical problems with the company's internal communication system were also mentioned. Tepco later pointed out frequent phone line and corporate network failures in the days after the earthquake; Some information had to be delivered personally.
- Pressure relief
Japanese nuclear engineer Kenzo Miya , a professor emeritus at the University of Tokyo , saw Naoto Kan's helicopter visit to the power plant in the early morning of March 12 as one of the reasons for the pressure relief delay. There was a risk of exposing the prime minister's helicopter to radioactive material. According to a report in the New York Times, government officials indicated that Tepco had generally shied away from radioactive emissions when the pressure was relieved. The newspaper also reported a heated discussion on the subject, in which Tepco's nuclear power chief Sakae Muto and Fukushima-I power plant manager Masao Yoshida yelled at each other.
Later published records of the employees in the power plant indicate mainly technical difficulties. While the Prime Minister and the regulator tried to use political pressure and official orders to force Tepco to open the valves on Block 1, employees struggled with systems that no longer worked after the flood and power failure. It took a while to find out (sometimes in the dark) how to open the valves by hand. The evacuation of the immediately adjacent places also played a role. The New York Times also explained the problems with the fact that the reactors developed in the USA were designed according to the specifications of the American nuclear regulatory authority , which had enforced major safety hurdles before a possible actuation of the pressure relief.
- Sea water cooling
The Wall Street Journal quoted former Tepco manager Akira Omoto, a member of the Japan Atomic Energy Commission , on March 21, 2011 as saying that Tepco had hesitated to discharge seawater in order not to damage the valuable reactors with the saltwater; the reactors can be destroyed in the process. This criticism was then reflected in various press articles. According to its own information and records, however, Tepco initially introduced fresh water into reactors 1 and 2 and - after the supplies were exhausted - switched to seawater. The delay up to the discharge of seawater was therefore a maximum of four hours and not - as assumed by the Wall Street Journal - about 12 or 30 hours (see the chronicle of the Fukushima nuclear catastrophe article ).
At the end of May 2011 there was a public discussion and dispute between Prime Minister Kan and the parliamentary opposition over a possible responsibility for the delayed seawater cooling. Tepco records indicated communication problems within the company and between power plant operators, authorities and the prime minister, possibly also a hesitant release of the salt water discharge by Kan.
- Cooling of the cooling pool
Too late cooling of the cooling pool was also criticized. Both Tepco and the government would have focused only on the reactors and disregarded the cooling tanks for the first two days. The Wall Street Journal quoted Tetsuya Kono, spokesman for the Japanese armed forces, as saying that they had not participated in the water cannon earlier because Tepco had not requested it. The military could not take action of its own accord. American experts criticized the cooling of the cooling basin in Unit 4 (see section “ Reactor Unit 4 ”) too late .
Tepco defended itself by stating that after the explosion in Block 1, they had been fully occupied with stabilizing Block 2, so they had no further resources available.
Third party support
In addition to the armed forces, other organizations believed that Tepco had used their support too late.
According to an unnamed US government employee, it initially seemed unthinkable for the Japanese to resort to American aid. The Japanese government has rejected various requests and offers from the USA to involve its experts in crisis management. In the United States there are many nuclear power plants of the same model as in Fukushima; therefore the US has both experience and its own interest in investigating the series of accidents. In the end, the US government was so annoyed by the Japanese stance that, according to the New York Times, it threatened the withdrawal of key military personnel and, according to Yomiuri Shimbun, even threatened the evacuation of all US citizens from Japan.
Various offers of help, for example from the German Federal Government to deploy equipment and experts from the nuclear technical assistance service , were not accepted or only accepted with a considerable delay. Experts and equipment from the French atomic energy company Areva were only brought in from France on March 17 ; an offer of help from the Sarkozy government was received the day after the disaster. At the time of the accident, over 100 Areva employees from Germany, the USA and France were in the country, 18 of whom were doing maintenance work in the immediate vicinity of reactor 4. Only two weeks after the accident, Areva chairwoman Anne Lauvergeon arrived on site with experts from the Marcoule nuclear facility .
The Japanese government's Nuclear Safety Commission , which has forty experts on nuclear accidents, has been criticized for failing to send one of them to Fukushima I.
Information policy
The information policy of both the power plant operator and the authorities was widely criticized.
Government spokesman Edano indicated in a press conference on March 12th that Tepco was insufficiently informing the government. Prime Minister Kan was very angry two days later at first hearing about the block 3 explosion from the media. In the following weeks, Tepco had to correct incorrectly (too high) reported radiation readings several times and thus received public reprimands from the government and NISA. A Tepco spokeswoman said there was a conflict between the pressure to publish the data (quickly) and the requirement for accuracy. Tepco explained the specific errors with a misconfiguration of the software used .
It happened that Tepco initially denied or ignored damage to the power plant - for example earthquake and core meltdown damage - and only admitted it when it could no longer be overlooked.
China repeatedly complained about insufficient information from the Japanese authorities. The USA, other member states of the IAEA , the chairman of the United Nations Environment Program and the World Meteorological Organization (also United Nations) felt that they were insufficiently informed.
In a representative poll by the TV station JNN three weeks after the start of the nuclear accidents, 83 percent of the Japanese surveyed found the information provided by the government to be insufficient. Mayors of affected communities also complained about a lack of information.
Working conditions in the power plant
The handling of the auxiliary workers, some of whom come from temporary employment agencies and who were subject to very harsh working conditions there before the crisis, was also criticized.
Due to the explosions and fires in the power plant, the radiation exposure on the site rose sharply at times. The Japanese Ministry of Health then increased the total allowable dose equivalent for male workers in nuclear power plants in emergency situations from 100 to 250 millisieverts per year. Critics pointed out that values above the limit set by the International Commission on Radiological Protection (ICRP) of 100 millisieverts per use or per year, experience has shown, directly damage body cells and the risk of cancer increases in percentage even for much lower exposure. Third-party companies working on behalf of Tepco in the power plant rejected the higher limit value. By April 15, 2011, 28 employees had received radiation doses above 100, but none had received a dose above 250 millisievert.
The workers were also inadequate; at times there was a lack of dosimeters and suitable and approved safety boots . One employee reported that workers instead tied plastic bags around their shoes with tape. When significant amounts of radioactive water appeared in a turbine hall and some employees stepped into the water with half-height work shoes, they sustained considerable injuries and radiation.
After the explosion in Unit 3, the facility was temporarily evacuated. After that, only around 180 workers remained on site at times - including 50 employees from Tepco - what was discussed in the media under the name " Fukushima 50 " (with echoes of the 47 Rōnin ).
From the beginning of May, Tepco provided the workers twice a day with meals that were prepared in the neighboring Fukushima Daini nuclear power plant . Until then, they had mainly fed on canned food.
Outside of working hours, the employees and helpers are accommodated in the J-Village sports center , 20 kilometers south of the power station; at the beginning there were sometimes spartan conditions.
Coping with the consequences of an accident
At the end of March 2011, the Yomiuri Shimbun reported on criticism from local authorities of the food safety measures. Each prefecture and municipality can determine for itself the criteria by which it tests agricultural products for radiation. The honest are the stupid, because their region receives stricter requirements. In addition, the blanket limit values for all types of products are inappropriate.
On the other hand, it was criticized that some highly contaminated foods were not banned because they only affected a small region. At that time, the authorities only set restrictions for entire prefectures and in some cases waived them in order not to burden the entire prefecture economically because of a “problem region”. Shortly afterwards, food bans began to be laid down for smaller regions and individual cities.
On April 29, 2011, Toshiso Kosako , a professor in the Department of Nuclear Technology at the University of Tokyo , resigned from his position as scientific advisor to the Japanese government on nuclear issues, to which Prime Minister Naoto Kan had appointed him on March 16, on serious allegations. According to Kosako, the government can only save itself from the nuclear crisis with emergency solutions and provisional solutions over time. Due to unclear decision-making processes, many measures are also not in compliance with the law . There is a lack of transparency when measuring radiation around the Fukushima Daiichi nuclear power plant. The government has not published the so-called SPEEDI analysis for a long time. The System for Prediction of Environmental Emergency Dose Information is a computer program for estimating and forecasting radioactive contamination and had predicted local dose rates of over 100 millisieverts per year for some areas outside the 30-kilometer zone around the power plant . The government had withheld the first results of this analysis from March 16-23 to avoid panic. The responsible Nuclear Safety Commission of Japan published the complete data only after Kosako's resignation.
Kosako was particularly outraged and concerned about the preliminary declaration by the Japanese Ministry of Culture and Technology on April 19 that no lower radiation limit should be set for kindergartens and primary schools in the Fukushima prefecture than the 20 millisieverts per year that apply to the entire disaster area. The ministry relied on the recommendations of the International Commission on Radiological Protection , which allow an annual radiation dose of up to 20 millisievert for both adults and children in the event of a nuclear accident .
Kosako justified his resignation by saying that the government ignored his advice. Prime Minister Kan, on the other hand, attributed it to differences of opinion between Kosako and other scientists. According to a May 1 report in the New York Times, Japanese experts found it difficult to agree on radiation limits. You are in a new situation for which there are no guidelines and the choices you have to make could have far-reaching consequences.
On May 2, representatives of the International Forum on Globalization handed over an Internet petition "signed" by around 50 Japanese and around 4,000 US, European and other citizens and groups to the Japanese government, which called for the “withdrawal of the inhuman decision of the Japanese government To force children to have radiation exposure of 20 millisieverts per year ”. As a justification, they referred to the statements of German experts in an article in Spiegel from April 21. In contrast to the guidelines of the Japanese Ministry of Culture, the petition did not take into account the fact that the surroundings of the schools and kindergartens in which the children spend the rest of the time probably have similar levels of radiation as the school grounds.
The follow-up costs of the tsunami and nuclear disaster are a major burden on the Japanese economy, which is already heavily indebted . In April 2011 they were estimated at up to 200 or 300 billion euros in the long term and put a strain on the country's creditworthiness. Lower radiation limits could result in significant additional costs for the decontamination of floors. The government played for time and pointed out that radioactive pollution would decrease significantly by July, as half of the emissions consisted of short-lived radioactive 131 I (eight days half-life). Most of the radiation exposure on the soil surfaces in Fukushima Prefecture at that time still came from the decay of 131 I.
In a survey by the newspaper Yomiuri Shimbun from May 13-15, 2011, 73 percent of the Japanese surveyed said they were dissatisfied with their government's management of the nuclear crisis.
At the end of May 2011, 15,000 Japanese parents submitted another petition to the Ministry of Education, calling for a limit of 1 millisievert per year for children. The ministry promised to have the soil surface removed in schools with a load higher than 0.001 millisievert per hour, equivalent to 9 millisievert per year.
In March 2015, 4 years after the tsunami, around 230,000 people were still living in emergency shelters such as container settlements and provisionally occupied apartments, as large parts of the safety zone evacuated in 2011 are still not decontaminated. After the completion of the decontamination of less heavily polluted areas, the total cost of which is estimated to be at least US $ 20.5 billion, approximately 55,000 people will be allowed to return to their original settlements. However, according to studies by the Japanese reconstruction agency, only around 10-20% of the population want to return, with families in particular often speaking out against a return.
In August 2015, cooling of the disaster reactors in Fukushima with seawater continued. More than 100,000 people are still evacuated. From 2017 [obsolete] , evacuees from areas that are no longer considered to be “heavily contaminated” will no longer receive any support from the state authorities and will thus be moved to return to the restricted areas. The recovery work for the radioactive material from the meltdowns will not begin before 2022 .
Effects on economy and society
The effects of the nuclear disaster - in particular the political effects in Germany such as the state elections in Baden-Württemberg in 2011 - were also referred to as the “Fukushima effect” in the public debate.
Japanese economy
The evacuations affected the production of several companies and suppliers near the power plant, including Toto , Alpine Electronics , Daio , Fujitsu , IHI , Fuji Xerox and Canon .
On March 17, the fund company Union Investment Real Estate closed its open-ended real estate fund Uni-Immo Global because the fund's properties in Japan were no longer valued and consequently no share prices could be determined.
The region around Fukushima plays a significant role in Japanese agriculture, fishing and food supply. The neighboring prefecture of Ibaraki produces in particular premium rice varieties and is the home of Japanese pig breeding. The radioactive pollution resulted in sales bans on various foods. The government promised compensation for affected farmers. Agricultural and fishing associations later made high claims for damages against the power plant operator.
As of March 26, several major shipping companies stopped calling at the ports of Tokyo and Yokohama due to concerns about radioactive contamination of the ships. This put a strain on world trade as goods had to be brought by land from southern Japan to the north.
There was a massive drop in demand in Japanese aviation. The number of foreign visitors fell in the second half of March 2011 by 75% compared to the previous year.
Since the other nuclear power plants in Japan were checked for their safety and almost all of them were switched off as a result of the disaster, the national electricity demand had to be met with fossil fuels. Due to the import of the raw materials required for this, as well as a decline in exports, Japan recorded its first trade deficit since 1980 in calendar year 2011.
Electricity shortage
After the failure of several nuclear and thermal power plants, there were bottlenecks in Tepco's supply network. Citizens were asked several times to save electricity. In addition, with the permission of the Prime Minister, Tepco carried out so-called "rolling blackouts" from March 14, 2011 until April, that is, alternating power cuts in various parts of the Tepco supply area. In addition, the power shortage has been exacerbated by the fact that Japan has two incompatible power grids of 50 Hz and 60 Hz .
Under the slogan Setsuden (saving electricity), Japan endeavored in the further course of the year to avoid renewed cuts in electricity by saving all consumers. With this program, the Japanese government aims to reduce electricity consumption by up to a fifth. 51 of 54 Japanese nuclear reactors were shut down in January 2012 - partly because of the consequences of the disaster, partly because of routine maintenance and partly as a safety measure due to insufficient tsunami protection.
On August 30, the government lifted electricity restriction orders that had been in effect since July 1.
At the beginning of May 2012, the last active Japanese nuclear power plant, Reactor 3 of the Tomari nuclear power plant, was temporarily shut down. For the first time in 42 years, Japan had to do without nuclear energy entirely. The country then obtained its electricity from thermal power stations, among other things .
Due to the complete shutdown of all nuclear power plants, electricity prices rose dramatically, in some regions by up to 38%. The resulting reduction in electricity consumption led to an increased mortality rate during very cold periods, which, according to a study by the Institute for Labor Economics of the Deutsche Post Foundation, resulted in the death of 1,280 people in the period 2011–2014. The study found that 19% of cold-related deaths in Japan during the observation period were due to increased electricity prices.
In view of warnings from the nuclear industry and the central government of power outages in the summer, the government issued instructions in mid-June 2012 to start up reactors 3 and 4 of the Ōi nuclear power plant . The power plant belongs to the KEPCO company . At the beginning of July 2012, reactor 3 went into operation despite protests from the population. It was the first commissioning after the nuclear disaster and after a period of only about two months without a nuclear reactor operating in Japan.
Japanese society
In the evacuation zone around the power plant, the rescue of tsunami victims was delayed due to the high radiation exposure. Because of the possible contamination, handover to relatives or cremation would also involve further dangers.
In Japan the expression Flyjin (from Gaijin , "foreigner" and Fly, English "flight" or "flight") made the rounds. This was used to refer to foreigners in the expat community who set off for their home country without saying goodbye after the first travel warnings. The exodus of foreigners also threatened the self-image of the Japanese during the crisis and made the economic difficulties even worse. There is also a considerable loss of confidence in people who have left temporarily.
People from Fukushima Prefecture were discriminated against , partly for fear of "radiation" . Kōichirō Gemba , Minister of Social Policy, reported rejections from hotels and victimized children.
On September 2, 2011, Yoshihiko Noda (until then finance minister) replaced Naoto Kan, who had been criticized for his crisis management, and became the new prime minister. Kan announced his resignation under certain conditions in June 2011.
Nuclear energy policy
The Gallup International Association , a worldwide network of polling institutes, carried out surveys in 47 countries on the use of nuclear energy between March 21 and April 10, 2011 . Accordingly, the proportion of nuclear power supporters fell from 57 to 49 percent compared to the last survey series before the Fukushima disaster, while the proportion of nuclear power opponents rose from 32 to 43 percent. 81 percent of those questioned would have known about the nuclear accidents in Fukushima. In the previous ten years, the global share of nuclear power supporters had risen steadily. The study was published on April 19, 2011 by WIN-Gallup International in Islamabad .
At the end of April, UN Secretary-General Ban Ki-moon pointed out that the safety of nuclear power plants urgently needed to be reviewed worldwide.
Japan
Prime Minister Naoto Kan initiated a review of the ongoing plans for the construction of 14 more nuclear power plants. Various power plant operators therefore froze their plans to build new reactors. Kan also pleaded for a spin-off of the Japanese nuclear regulatory authority NISA from the Ministry of Economic Affairs, which had actively promoted the use of nuclear energy in Japan.
The nuclear disaster brought about a fundamental change in the attitude of the Japanese people towards nuclear energy. From March 27 to March 31, there were first notable demonstrations; about 100 to 1000 opponents of nuclear power gathered in front of the Tepco headquarters in Tokyo. On April 10, 17,500 people demonstrated against nuclear power plants in Tokyo; more rallies followed. According to a survey by the Gallup International Organization, approval of the civil use of nuclear energy fell from 62 to 39 percent of the Japanese in the first few weeks of the accident, while the proportion of those who opposed nuclear power increased from 28 to 47 percent. This change of opinion was greater than in any other country surveyed by Gallup.
In May, the government shut down the Hamaoka nuclear power plant because it was not adequately protected against the effects of the earthquake, and discussed the need for greater use of renewable energies instead of the previously planned further expansion of nuclear energy.
The restart of the power plants that were shut down after the earthquake was delayed due to reservations by the population, represented by the local authorities. Although the decision on this ultimately rests with the Ministry of Economic Affairs, the prefectures and municipalities are traditionally given a say. An attempt by 400 Tepco shareholders to shut down the company's three power plants (Fukushima Daiichi, Fukushima Daini and Kashiwazaki-Kariwa ) by resolution of the general meeting failed.
In June / July there was a scandal surrounding the Genkai nuclear power plant , which should be the first to go back into operation. Public debates on this topic were manipulated on a large scale by the operating company Kyūshū Denryoku . This and other power plants were then shut down. The nuclear power plant operators Chūbu Denryoku and Shikoku Denryoku were also suspected of being tampered with, as was the nuclear regulatory authority NISA, whose director was dismissed at short notice.
The government decided to spin off NISA from the Ministry of Economic Affairs in April 2012 and, together with the staff of the Nuclear Safety Commission of Japan, to join the Ministry of the Environment . Critics questioned the competence of the Ministry of the Environment in matters of nuclear energy and pointed out that the independence of the nuclear supervision from the government, which the IAEA has called for for years, is still not guaranteed. On September 19, 2012, this project was implemented and both organizations were replaced by the Nuclear Regulation Authority .
On September 14, 2012, the Japanese government decided at a ministerial meeting in Tokyo to gradually phase out nuclear energy by the 2030s, but at the latest by 2040. The government announced that it wanted to take “all possible measures” to achieve this goal . A few days later, the government restricted the planned nuclear phase-out again after the industry urged it to reconsider the plans. The arguments given were that a nuclear phase-out would burden the economy and that the import of oil, coal and gas would lead to high additional costs. The government thereupon approved the energy transition, but left the time for the decommissioning of the nuclear power plants open.
In December 2012 there was a change of government after the 2012 Shūgiin election : the former Prime Minister Shinzō Abe was again Prime Minister. He is considered an advocate of nuclear power.
In 2015, two reactors were connected to the grid again for the first time; they are located in southwestern Japan. By mid-June 2017, a total of five reactors were back on the grid nationwide, the last of which was only restarted at the beginning of the month at the Takahama nuclear power plant . In addition, a court approved the recommissioning of two reactors in the Genkai nuclear power plant in mid-June 2017 , contrary to the resistance of the residents and their accusation against the power plant operator of insufficient protection of the plant against natural disasters.
European Union
On March 25, 2011, the European Union decided to propose voluntary tests to all nuclear power plant operators in its 27 member states based on uniform criteria that have yet to be agreed. Independent experts should review risks such as natural disasters, man-made accidents such as plane crashes and terrorist attacks by the end of 2011. After weeks of dispute, the nuclear supervisory authorities of the member states agreed on criteria for a binding, "stress test", which began on June 1, 2011 and should be completed by the end of April 2012. Risks from terrorist attacks were not included.
The final report was delayed because of the vortex behind the scenes and additional audits. On October 4, 2012, the EU published a 20-page paper.
The final report shows safety deficiencies and defects in almost all European nuclear power plants; the repair costs of the 134 power plants examined were estimated at up to 25 billion euros. According to a report by Le Figaro , quoted in the newspaper Die Presse , none of the 58 nuclear power plants in France meets the safety standards of the International Atomic Energy Agency (IAEA).
Germany
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In Germany , the accidents intensified the ongoing debate about the use of nuclear energy and the extension of the service life of German nuclear power plants, which had only been decided a few months earlier . On March 14, 2011, Chancellor Angela Merkel announced that all 17 German nuclear power plants should be subjected to a safety check for three months ( nuclear moratorium ). Shortly thereafter, the decision was made to shut down the seven oldest nuclear power plants in Germany and the Krümmel nuclear power plant for the time being, or to leave them shut down. The implementation was left to the federal states in which these power plants are located.
As has been foreseeable for months by forecasts, the Greens achieved well over 20% in the state elections in Baden-Württemberg in 2011 on March 27, 2011 and appointed Winfried Kretschmann for the first time as a Prime Minister. According to a survey by Gallup International on March 29, 2011, the proportion of nuclear power supporters in Germany fell from 34 to 26 percent, while the proportion of nuclear power opponents rose from 64 to 72 percent.
On June 30, 2011, the Bundestag and Bundesrat decided with a clear majority that the seven oldest German nuclear power plants and the Krümmel nuclear power plant should be shut down immediately, and that all other German nuclear power plants should be shut down by 2022 (→ see nuclear phase-out ).
Other states
Some states such as India , Pakistan , Russia and Spain announced an inspection of their operating nuclear power plants. Venezuela's President Hugo Chavez and Israel's Prime Minister Benjamin Netanyahu said they wanted to stop plans for the first nuclear power plant in their countries. The People's Republic of China froze permits for all new nuclear power plants.
The Switzerland prompted an immediate review of all nuclear power plants and then planned a time limitation of 50 years and a complete phase-out by the 2034th
France ( President Sarkozy's Fillon III Cabinet ), Indonesia , the Netherlands ( Rutte I Cabinet ), Turkey ( Erdoğan II Cabinet ), Vietnam and Belarus announced that they would stick to their plans for new nuclear power plants.
US President Barack Obama ordered a safety review of all US nuclear power plants . The review showed that the safety precautions against serious accidents at some power plants are inadequate.
Italy's government ( Berlusconi IV cabinet , May 2008 to November 2011) suspended a planned re-entry into nuclear energy for one year. A referendum in June 2011 confirmed the exit with a large majority.
The political discussions continued. In France, approval of nuclear energy slowly declined and by June 2011 turned into a long-term wish for a majority of the population to opt out.
Tepco's analysis, liability and financing
Tepco's analysis
In a report published on October 12, 2012, Tepco's internal commission of inquiry, headed by company president Naomi Hirose, admitted that the company had failed to take more decisive measures to avoid disasters like that of Fukushima, as it was feared that this would indirectly lead to (1 ) Lead protests or legal actions, (2) encourage anti-nuclear attitudes in the population and (3) could have a negative impact on power plant operations. In the commission report, Tepco confirms that the consequences of the accident could have been reduced if the energy supply and cooling systems of the plant had been designed more redundantly in accordance with international standards.
In addition, the report admits that Tepco should not have allowed the emergency drills to be completed as a mandatory formality rather than as practical crisis management exercises.
Tepco continues: "There were fears that if further measures had been taken against serious accidents - there would be concerns in the host communities (the reactors) about safety problems of the current power plants." It is reported that as early as 2002 measures against serious accidents Accidents were taken that affected the pressure relief in an emergency as well as the connection of the energy supply systems with each other, but that further measures were never implemented, as these “could lead to public uncertainty and strengthen the anti-nuclear movement”.
Cost and liability
Depending on the source, the costs of the reactor catastrophe are estimated at between 150 and approx. 187 billion euros (as of October 2013). According to the Japanese Nuclear Liability Act, the operators of nuclear power plants are strictly liable for nuclear damage regardless of fault , provided this was not caused by an exceptionally serious natural disaster or a riot. Government spokesman Edano said the application of the natural disaster exception was impossible under the given social circumstances.
Operation of the reactor is only permitted if the operator concludes both a private liability insurance contract and an indemnity agreement with the state for damage not covered by the insurance. A coverage of 120 billion yen (at that time the equivalent of around one billion euros) per installation is required. The private insurance of the Japanese nuclear pools (Japan Atomic Energy Insurance Pool) does not cover damage caused by earthquakes. If the damage exceeds the sum insured, the state can support the operator by resolution of the Japanese parliament in meeting the claims for damages.
Damage from radioactive contamination is not covered by insurance for the injured party. The major reinsurers Swiss Re and Munich Re did not expect any significant burden on the insurance industry from the nuclear accidents (as of May 2011).
In mid-April 2011, Tepco was obliged by law to provisionally provide financial compensation to both the people evacuated from the vicinity of the power plant and those who should not leave their homes. Tepco paid one million yen for each multi-person household - at that time this was equivalent to around € 8,300 - and 750,000 yen for each single household, corresponding to € 6,250. 50,000 households received a total of around 50 billion yen (€ 415 million). In the meantime, the amount of compensation for private households has risen to around 7.7 trillion yen (~ 60 billion €). (As of January 2018) A little later, a government commission confirmed that Tepco had to bear the economic losses from bans and voluntary restrictions on the sale of agricultural and fishery products. Tepco could not invoke the disclaimer clause in the event of natural disasters because the company was aware of the inadequate protection of the plant against tsunamis. The total compensation for agriculture in December 2011 was estimated at around 1 billion euros. The majority of this had already been paid out by this point.
financing
Due to the accident costs and the failure of further power plants after the earthquake, Tepco got into financial difficulties and on March 23, asked seven major Japanese banks for loans equivalent to 17 billion euros, with which the damage from the reactor disaster should be paid. The rating agencies Moody’s and Standard & Poor’s had previously downgraded Tepco 's creditworthiness. The banks made the requested loans available within three weeks.
The Japanese government was considering splitting the company. The Fukushima I power plant would therefore be separated from the group and nationalized. This would mean that the Japanese state would also be responsible for the compensation payments as a result of the disaster. Independently of this, the government promised to support the company if it could not bear the costs of the nuclear disaster on its own. On May 10, Tepco responded to this offer and officially asked the state for financial support.
In September the government set up its own law, a " Lex Tepco", a support fund called the Nuclear Damage Compensation Facilitation Corporation , which is financed mainly through government-guaranteed bonds , initially with one Volume of the equivalent of up to 18 billion euros. Nine of the ten regional Japanese electricity suppliers and other companies in the nuclear industry are also making contributions. If necessary, the fund provides the power plant operator with money to finance compensation payments, which must be repaid in installments.
In the financial statements of the fiscal year 2010/11 (31 March 2011) registered Tepco expenses and provisions of 884 billion yen (equivalent to 7.5 billion euros) for previously accrued and other expected costs of nuclear accidents. Of this, 426 billion yen was accounted for by the stabilization and security measures in the power plant, 207 billion yen for the planned demolition of reactor units 1 to 4, 212 billion yen for the ongoing operating costs of the shutdown units 5 and 6 and 39 billion yen for the The planned blocks 7 and 8 are abandoned . Tepco put the repair costs for other systems damaged by the earthquake and tsunami at 133 billion yen. After the figures were announced, President Shimizu Masataka and three other directors announced their resignation at the Annual General Meeting on June 28, 2011. Another 1076 billion yen (around € 10 billion) was added in the first half of the 2011/12 financial year, the majority of which was for compensation expenses.
Processes
The public prosecutor's office ruled twice against charges against Tepco managers. Citizens and protest groups vigorously urged Tepco managers to be tried. Only after two citizen juries voted for the indictment in a very seldom used procedure, three Tepco managers were indicted in 2016: Tsunehisa Katsumata (77), the former CEO of Tepco, as well as the two former vice-presidents Sakae Muto (66) and Ichiro Takekuro (71 years).
This process began in June 2017. It is the first criminal case in Japan to come to terms with the nuclear disaster. The defendants are accused of neglecting their official duties. They are charged with the deaths of 44 people, including patients who were evacuated from near the nuclear power plant and died in the process.
In March 2018, a court in Kyoto found the Japanese government and the operating company Tepco to be responsible for the Fukushima disaster. The state and companies were sentenced to pay the equivalent of 835,000 euros. The government was to some extent able to foresee the risk of a tsunami. The state failed to ask Tepco to take protective measures.
In September 2019, all three Tepco managers were acquitted because the tsunami could not have been foreseen.
reception
One of the workers on the site of the destroyed nuclear power plant was the Japanese mangaka Kazuto Tatsuta . In order to protect himself from his employer, he describes his experiences in the three-volume manga Reaktor 1F - A report from Fukushima under this pseudonym . Information from the interior of the largely inaccessible site and the destroyed buildings was also presented, which was largely unknown until publication. The German editions of the manga were published by Carlsen Verlag .
In the 2015 album Werwolf-Attacke - Monsterball ist everywhere by the music group EAV , the song Burli , released in 1987 in response to the Chernobyl nuclear disaster , is continued with the piece Mrs. Fuckushima .
The German feature film Greetings from Fukushima , released in 2016, deals with how those affected deal with their loss of home and property.
Quarks & Co , the science television magazine of the WDR , reported several times and from the beginning on the triple disaster, in particular on the events in Fukushima. One year later, on March 6, 2012, the incident and its consequences were reported under the title The Fukushima Disaster . The program entitled Fukushima - the end not in sight four years later was informed about the status of the clean-up work on the reactor and in the region .
See also
- Chronology of the 2011 disaster in Japan , Chronicle of the Fukushima nuclear disaster
- Nuclear energy in japan
- Reactor safety
- List of accidents in nuclear facilities
literature
- Federal Office for Radiation Protection [Ed.]: The disaster in the Fukushima nuclear power plant after the seaquake of March 11, 2011: Description and assessment of the process and causes , also online download page (PDF; 23 MB), accessed on March 15, 2015.
- Helen Caldicott [Ed.]: Crisis Without End: The Medical and Ecological Consequences of the Fukushima Nuclear Catastrophe. [The contributions of a symposium at the New York Academy of Medicine, held March 11-12, 2013]. The New Press, New York 2014. ISBN 978-1-59558-970-5 (eBook)
- Tomohiko Suzuki: Inside Fukushima. A report from inside the catastrophe , Association A, Hamburg 2017, ISBN 978-3-86241-458-1 .
Web links
Wikinews: Fukushima I Nuclear Power Plant - in the news- Inside Japan's Nuclear Meltdown - PBS Frontline Documentation (Video, 55 min., English)
- Press releases (English) from the power plant operator Tepco
- Webcam Fukushima I nuclear power plant, recorded since March 11 ( memento from March 19, 2011 in the Internet Archive )
- Reports from the Japanese Nuclear Regulatory Authority (NRA) ( Memento from August 6, 2014 in the Internet Archive )
- The 2011 off the Pacific coast of Tohoku Pacific Earthquake and the seismic damage to the NPPs ( Memento from April 13, 2011 on WebCite ), compilation of the course of the accident by NISA (archive)
- The Tohoku-Taiheiyou-Oki Earthquake and Subsequent Tsunami on March 11, 2011 and Consequences for Nuclear Power Plants in Northeast Honshu (English; PDF; 5.2 MB), collection of materials on the course of the accident, Ludger Mohrbach and Thomas Linnemann, VGB PowerTech ( archive from April 13, 2011 ( Memento from April 13, 2011 on WebCite )
- Document collection of the Japanese authorities on protective measures for the population (PDF, English)
- Fukushima in Germany too? Background article in the spectrum of science from July 25, 2011
- Interactive map of the radiation distribution ( memento from October 20, 2011 in the Internet Archive ) of the Ministry of Education and Science in Japan (Japanese; click on the button at the bottom left)
- Fukushima Daiichi Nuclear Power Station Photos 20, 28 February 2012 at Cryptome
- 365 days of Fukushima - information brochure of the Society for Plant and Reactor Safety GRS (mbH) from March 7, 2012
- Overview map of radiation exposure in Japan, constantly updated
- Melanie Arndt: Fukushima is not Chernobyl? In: Contemporary History Online. Center for Contemporary History, March 2011, accessed on January 17, 2015 .
- Susanne Pötzsch: Pictures of Destruction. Fukushima in the film , on Zeitgeschichte-online , March 2012
- Deutschlandfunk.de , Dossier , March 4, 2016, Judith Brandner : Japanese nuclear power plants. Day laborers at the reactor.
- Fukushima - Five years after the reactor accident. Society for Plant and Reactor Safety (GRS), March 7, 2016, accessed on March 27, 2016 . Radiological situation and current work on the Fukushima nuclear power plant: an overview- a summary of the changes in the new edition of the GRS Fukushima report, specifically Fukushima Daiichi March 11, 2011 (5th revised edition, March 2016, PDF).
- Inside Fukushima's Time Bomb . Al Jazeera English, August 2016 (video, English, 25 min.)
Individual evidence
- ↑ dlr.de : DLR published satellite images of Japanese disaster area (23 December 2016)
- ↑ a b c Earthquake Report - No. 61: 18:00, April 23 (English, pdf). JAIF / NHK, April 23, 2011, archived from the original on April 23, 2011.
- ↑ Ulli Kulke: Roth in the vortex of the "atomic victims" of Fukushima , WeltN24, March 12, 2013.
- ↑ a b c d INES (the International Nuclear and Radiological Event Scale) Rating on the Events in Fukushima Dai-ichi Nuclear Power Station by the Tohoku District - off the Pacific Ocean Earthquake ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA / METI, April 12, 2011.
- ↑ Tokyo Electric to scrap 4 reactors at crippled nuclear plant (English). Kyodo News, archived from the original on April 9, 2011, retrieved on April 9, 2011.
- ↑ Fukushima nuclear plant to be decommissioned: Gov't (English). Kyodo News, March 20, 2011, archived from the original on April 10, 2011, retrieved on March 21, 2011.
- ↑ Nuclear Power Reactors in the World, 2018 Edition, Table 16, page 49 , accessed on August 29, 2019. IAEA, Vienna, 2018, ISBN 978-92-0-101418-4 .
- ↑ a b c d e Global Snap Poll on Earthquake in Japan and Its Impact on Views About Nuclear Energy ( Memento from April 21, 2011 on WebCite ) (English, pdf). WIN-Gallup International, April 19, 2011 (PDF; 509 kB).
- ↑ Tepco defends itself against nationalization . Retrieved March 22, 2018 . . Deutschlandfunk, December 27, 1011.
- ↑ a b Fukushima Daiichi Nuclear Plant Hi-Res Photos . Retrieved March 22, 2018 . (English). Cryptome, March 31, 2011. With red truck-mounted concrete pump for water cooling of Block 4; Image 3 reversed.
- ^ Detection of radioactive materials in tap water in Fukushima Prefecture and Tokyo . (PDF) Retrieved March 22, 2018 . (English, pdf). Japanese Ministry of Health, March 23, 2011 (PDF; 195 kB).
- ↑ Official probe begins into nuclear disaster ( Memento from December 19, 2011 on WebCite ). The Japan Times, June 8, 2011.
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq Report of Japanese Government to the IAEA Ministerial Conference on Nuclear Safety - The Accident at TEPCO's Fukushima Nuclear Power Stations - IV. Occurrence and Development of the Accident at the Fukushima Nuclear Power Stations ( Memento June 13, 2011 on WebCite ). Kantei / NISA, June 7, 2011, (PDF; 4.3 MB), accessed June 14, 2011.
- ↑ a b Impact to TEPCO's Facilities due to Miyagiken-Oki Earthquake (as of 3PM) ( Memento from April 3, 2011 on WebCite ) (English). Tepco, March 12, 2011.
- ↑ a b c Fukushima Nuclear Accident Update Log (March 15, 2011, 18:00 UTC) ( Memento from April 9, 2011 on WebCite ) (English). IAEA, March 15, 2011.
- ↑ MOX fuel loaded into Tokyo Electric's old Fukushima reactor ( Memento from May 2, 2011 on WebCite ). Japan Today, August 28, 2010.
- ↑ IAEA - Annual Report on Nuclear Power Plants in Member States ( Memento from September 22, 2011 on WebCite ) (pdf). IAEA, accessed September 22, 2011.
- ↑ More on Spent Fuel Pools at Fukushima ( Memento April 9, 2011 on WebCite ). All Things Nuclear, March 21, 2011.
- ↑ a b Technical data Fukushima No. 1 in normal operation ( Memento from April 6, 2011 on WebCite ) (pdf). GRS (PDF; 50 kB).
- ↑ 東京 電力 福島 第一 原 発 、 電源 引 き 込 み 工事 始 ま る (Japanese). In: asahi.com . Asahi Shimbun, March 19, 2011, accessed May 23, 2011.
- ^ A b Ludger Mohrbach and Thomas Linnemann: The Tohoku-Taiheiyou-Oki Earthquake and Subsequent Tsunami on March 11, 2011 and Consequences for Nuclear Power Plants in Northeast Honshu ( Memento from April 13, 2011 on WebCite ) (English, pdf). VGB PowerTech , April 3, 2011, accessed on June 5, 2011. Damaged condensation chamber on p. 55, heat output in the cooling pool on p. 60.
- ↑ Brief overview of the current security situation ( memento of April 9, 2011 on WebCite ) (pdf). Society for Plant and Reactor Safety , March 19, 2011 (PDF; 24 kB).
- ↑ Proof of plutonium on the site of the Fukushima Daiichi nuclear power plant . ( Memento from April 9, 2011 on WebCite ) GRS.
- ↑ Fukushima Accident 2011 ( Memento from April 4, 2011 on WebCite ) (English). World Nuclear Association, April 2, 2011.
- ↑ a b c Earthquake Report - JAIF No. 51: 20:00, April 13 . ( Memento from April 13, 2011 on WebCite ) JAIF / NHK, April 13, 2011 (PDF; 124 kB)
- ↑ a b c d e Discharge of low level radioactive accumulated water in the Fukushima Daiichi Nuclear Power Station to the sea (2nd Release) ( Memento from April 9, 2011 on WebCite ) (English). Tepco, April 4, 2011.
- ↑ The 2011 off the Pacific coast of Tohoku Earthquake ~ first report ~ ( Memento from April 1, 2011 on WebCite ) (English). Japan Meteorological Agency, March 13, 2011.
- ↑ Magnitude 9.0 - Near the East Coast of Honshu, Japan ( Memento April 11, 2011 on WebCite ) (English). United States Geological Survey , March 14, 2011.
- ↑ a b c 警報 発 生 記録 等 デ ー タ 1 号 機 (Alarms and data recording block 1) ( Memento from May 19, 2011 on WebCite ) (Japanese). Tepco, May 16, 2011, (PDF; 6.2 MB), accessed on May 19, 2011.
- ↑ a b Dave Lochbaum: Fukushima Dai-Ichi Unit 1: The First 30 Minutes ( Memento from May 27, 2011 on WebCite ) (English). Union of Concerned Scientists, May 25, 2011 (PDF; 1.4 MB), accessed on May 27, 2011.
- ↑ a b c 過渡 現象 記録 装置 デ ー タ 1 号 機 (Short-term data recording block 1) ( Memento from May 19, 2011 on WebCite ) (Japanese). Tepco, May 16, 2011, accessed on May 19, 2011. HPCI on page 14f, Isolation Condenser on page 16ff, emergency power generators on page 29ff.
- ↑ a b c Damages to Electric Facilities at Fukushima Daiichi Nuclear Power Station (after Tsunami) ( Memento from May 17, 2011 on WebCite ) (English). Tepco, May 16, 2011 (PDF; 47 kB).
- ↑ a b c Occurrence of a Specific Incident Stipulated in Article 10, Clause 1 of the Act on Special Measures Concerning Nuclear Emergency Preparedness (Fukushima Daiichi) ( Memento from April 3, 2011 on WebCite ) (English). Tepco, March 11, 2011.
- ↑ a b Damage to inhouse power supply facilities at Fukushima Daiichi Nuclear Power Station (after Tsunami) ( Memento from May 25, 2011 on WebCite ) (English). Tepco, May 16, 2011, (PDF; 44 kB), accessed on May 25, 2011.
- ↑ Summary of the Report on the Analysis of Observed Seismic Data Collected at Fukushima Daiichi Nuclear Power Station and Fukushima Daini Nuclear Power Station pertaining to the Tohoku-Taiheiyou-Oki Earthquake ( Memento from May 20, 2011 on WebCite ) (English, pdf). Tepco, May 16, 2011 (PDF; 544 kB).
- ↑ a b c d e f Earthquake Report - JAIF, No. 93 ( Memento from May 26, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 26, 2011 (PDF; 130 kB).
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw Additional Report of the Japanese Government to the IAEA ( Memento from December 11, 2011 on WebCite ) (English, pdf, 31 MB). Kantei , September 15, 2011.
- ^ A b Result of the investigation on Tsunami at the Fukushima Daiichi Nuclear Power Station ( Memento from April 24, 2011 on WebCite ) (English). Tepco, April 9, 2011 (PDF; 395 kB).
- ↑ Results of the investigation regarding tsunami arrived in Fukushima Daiichi Nuclear Power Station and Fukushima Daini Nuclear Power Station ( Memento from April 11, 2011 on WebCite ) (English). Tepco, April 9, 2011.
- ↑ a b c d e f g h i j k Mission Report: The Great East Japan Earthquake Expert Mission ( Memento from June 26, 2011 on WebCite ) (English, pdf). IAEA, June 16, 2011, accessed June 25, 2011: “Interactions between NISA and TEPCO could benefit from the development of technical depth rather than formal regulatory relations. This may need an enhancement of NISA's technical capability. "
- ↑ a b c d e The Results of a Safety Investigation into the Accident at Tokyo Electric Power Co.'s Fukushima Dai-ichi Nuclear Power Station ( Memento of December 11, 2011 on WebCite ) (English, pdf). NISA, September 16, 2011.
- ↑ Massive earthquake hits Japan ( Memento from April 11, 2011 on WebCite ) (English). World Nuclear News, March 11, 2011.
- ↑ a b c TEPCO documents reveal chaos at Fukushima nuke plant after quake, tsunami ( Memento from May 19, 2011 on WebCite ) (English). The Mainichi Daily News, May 17, 2011, accessed May 19, 2011.
- ↑ a b c d e f g TEPCO tardy on N-plant emergency ( Memento from May 14, 2011 on WebCite ) (English). Yomiuri Shimbun , April 12, 2011.
- ↑ a b Earthquake Report - JAIF, No. 84 ( Memento of May 17, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 17, 2011 (PDF; 113 kB).
- ↑ a b c Хронология вебкамеры на японскую АЭС "Фукусима-1" (webcam) (Russian). libres, March 13, 2011, accessed May 16, 2011. Archived as a copy ( Memento of May 17, 2011 on WebCite ) on May 17, 2011.
- ↑ a b c U.S. See's Array of New Threats at Japan's Nuclear Plant , New York Times (April 5, 2011), accessed April 7, 2011; archived on April 7, 2011: p. 1 ( memento of April 7, 2011 on WebCite ), p. 2 ( memento of April 8, 2011 on WebCite )
- ↑ a b Earthquake Report - JAIF . ( Memento from April 11, 2011 on WebCite ) JAIF, April 11, 2011 (PDF; 109 kB)
- ↑ a b c d Earthquake Report - JAIF, No. 50 . ( Memento from April 12, 2011 on WebCite ) JAIF / NHK, April 12, 2011 (PDF; 146 kB).
- ↑ Neutron beam observed 13 times at crippled Fukushima nuke plant ( Memento from May 23, 2011 on WebCite ). Kyodo News, March 23, 2011, accessed May 23, 2011.
- ↑ a b Outline of Warter Injection to RPVs ( Memento from March 21, 2011 on WebCite ) (English, pdf). NISA, March 14, 2011
- ↑ a b c d e f g Seismic Damage Information (the 54th Release) ( Memento from April 10, 2011 on WebCite ) (English, pdf). NISA, March 26, 2011.
- ↑ a b c d e f Norimitsu Onishi and Martin Fackler: In Nuclear Crisis, Crippling Mistrust ( Memento from June 24, 2011 on WebCite ) (English). New York Times, June 12, 2011 of the original , accessed June 18, 2011.
- ↑ Earthquake Report - JAIF, No. 7 . ( Memento from April 28, 2011 on WebCite ) JAIF, March 15, 2011 (PDF; 47 kB)
- ↑ Progress by on-site workers ( Memento April 11, 2011 on WebCite ). world nuclear news, March 17, 2011.
- ↑ Christoph Neidhart: Workers in the Fukushima 1 reactors - The saviors of Japan . Süddeutsche Zeitung , March 21, 2011, accessed on March 24, 2011. Archived print version. ( Memento from April 12, 2011 on WebCite )
- ↑ Live ticker . ( Memento from May 2, 2011 on WebCite ) Hannoversche Allgemeine, March 18, 2011: “Almost 140 firefighters from Tokyo on duty in Fukushima”.
- ↑ Minister Kaieda sorry for reportedly 'forcing' water-spraying mission ( Memento from March 22, 2011 on WebCite ). Kyodo News, March 22, 2011
- ↑ Disrupted work resumes to restore power at Fukushima reactors ( Memento from April 11, 2011 on WebCite ). Kyodo News, March 22, 2011.
- ↑ a b c d e Joseph Shepherd: The Crisis at Fukushima Dai-ichi Nuclear Power Plant ( Memento from April 27, 2011 on WebCite ) (English, pdf). California Institute of Technology , April 24, 2011.
- ↑ Putzmeister pump for Japan ( Memento from July 13, 2012 in the Internet Archive ) (see also Putzmeister )
- ↑ Information on the situation in Japan: As of March 25, 2011, 1:00 p.m. (CET) . ( Memento from April 11, 2011 on WebCite ) GRS, March 25, 2011.
- ↑ a b Minutes: This is how Friday went in Japan . ( Memento from May 3, 2011 on WebCite ) Spiegel Online: "The operator Tepco hopes to be able to put the cooling system in reactor 2 back into operation on Friday night (local time)."
- ↑ The Great East Japan Earthquake and Current Status of Nuclear Power Stations ( Memento from April 25, 2011 on WebCite ) (English, pdf). Tepco, April 18, 2011. Earthquake load on p. 28.
- ↑ a b c Status of nuclear power plants in Fukushima as of 10:00 March 26 (Estimated by JAIF) ( Memento from May 3, 2011 on WebCite ) (English, pdf). March 26, 2011 (PDF; 855 kB): "Main Control Room Habitability & Operability: Poor due to loss of AC power (Lighting has been recovered.)".
- ↑ Earthquake Report - JAIF, No. 36 ( Memento of April 27, 2011 on WebCite ) (English, pdf). March 29, 2011 (PDF; 91 kB): "Machines and equipment to restore automatic cooling systems for the reactors are installed inside the turbine buildings. But the delay in draining contaminated water is blocking restoration. "
- ↑ Seismic Damage Information (the 50th Release, As of 08:00 March 25th, 2011) ( Memento from April 11, 2011 on WebCite ) (English, pdf). NISA, March 25, 2011.
- ↑ a b Fukushima Nuclear Accident Update Log ( Memento from April 15, 2011 on WebCite ) (English). IAEA, April 15, 2011.
- ↑ a b Air may be leaking from reactors No. 2 and 3 ( Memento from May 15, 2011 on WebCite ) (English). NHK, March 30, 2011, accessed May 15, 2011.
- ↑ a b c Cores Damaged at Three Reactors ( Memento from May 17, 2011 on WebCite ) (English). Wallstreet Journal, May 16, 2011.
- ↑ a b Earthquake Report - JAIF, No. 92 ( Memento from May 25, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 25, 2011 (PDF; 112 kB)
- ^ New Problems at Japanese Plant Subdue Optimism ( Memento from May 14, 2011 on WebCite ). New York Times, March 23, 2011.
- ↑ Fresh coolant injected, high-radiation water leaks in nuke crisis ( Memento from April 1, 2011 on WebCite ). Kyodo News, March 25, 2011, accessed April 1, 2011.
- ↑ US Naval Barges Bring Fresh Water to Assist with Cooling at Japan Nuclear Plant ( Memento April 11, 2011 on WebCite ). Huffington Post, March 26, 2011.
- ^ Fukushima Accident 2011 ( Memento from April 5, 2011 on WebCite ) (English, pdf). World Nuclear Association , April 4, 2011.
- ↑ Woes deepen over radioactive water at nuke plant, sea contamination ( Memento from April 15, 2011 on WebCite ) (English). Kyodo News, March 28, 2011, accessed April 15, 2011.
- ^ Removal of 60,000 tons of radioactive water eyed at Fukushima plant ( Memento from April 12, 2011 on WebCite ) (English). Kyodo News, April 5, 2011. Retrieved April 5, 2011.
- ^ Fears of radioactive seawater grow near nuke plant despite efforts ( Memento April 12, 2011 on WebCite ). Kyodo News, March 26, 2011, accessed April 12, 2011, accessed March 26, 2011.
- ↑ a b Seismic Damage Information (the 60th Release) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 29, 2011.
- ↑ a b Out flow of fluid containing radioactive materials to the ocean from areas near intake channel of Fukushima Daiichi Nuclear Power Station Unit 2 ( Memento from April 12, 2011 on WebCite ) (English). Tepco, April 2, 2011
- ↑ a b c d e Earthquake Report - JAIF, No. 68 ( Memento from May 1, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 1, 2011 (PDF; 338 kB).
- ↑ Radioactive water keeps workers out ( Memento from May 17, 2011 on WebCite ) (English). The Japan Times, March 29, 2011.
- ^ Fukushima Nuclear Accident Update Log ( Memento April 2, 2011 on WebCite ). IAEA, March 28, 2011.
- ↑ Nuclear disaster in Japan: operator checks sarcophagus construction like in Chernobyl . ( Memento from April 9, 2011 on WebCite ) Spiegel Online, March 18, 2011.
- ↑ Atomic Agency: Another place is to be evacuated; Disaster in Fukushima . ( Memento from April 2, 2011 on WebCite ) In: abendblatt.de . Axel Springer, March 30, 2011
- ^ Japan seeks Russian help to end nuclear crisis. Retrieved March 22, 2018 . Reuters, by Chizu Nomiyama and Shinichi Saoshiro TOKYO April 4, 2011
- ↑ Information on the situation in Japan: As of April 7, 2011, 1:00 p.m. (CEST) . ( Memento from April 10, 2011 on WebCite ) GRS, April 7, 2011.
- ↑ Seismic Damage Information (the 107th Release) ( Memento from April 22, 2011 on WebCite ) (English, pdf). NISA, April 22, 2011.
- ↑ a b c d e Earthquake Report - JAIF, No. 65 ( Memento of April 27, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 27, 2011 (PDF; 103 kB)
- ↑ Start of Spray of Dust Inhibitor to the Radioactive Materials around the Turbine Buildings and Reactor Buildings of Unit 1-4 of Fukushima Daiichi Nuclear Power Station ( Memento from May 26, 2011 on WebCite ). Tepco, May 26, 2011.
- ↑ a b TEPCO aims for cold shutdown in 6-9 months, but no guarantees ( Memento from May 17, 2011 on WebCite ) (English). In: asahi.com . April 19, 2011, accessed May 15, 2011.
- ↑ Radioactivity in water dumped from Fukushima plant lower than thought ( Memento from April 15, 2011 on WebCite ) (English). Kyodo News, April 16, 2011, accessed April 15, 2011.
- ^ Regarding a letter of protest from the National Federation of Fisheries Cooperative Associations ( Memento of April 9, 2011 on WebCite ). Tepco, April 6, 2011.
- ↑ a b China accuses Japan of deliberate deception . ( Memento from April 13, 2011 on WebCite ) Spiegel Online, April 13, 2011.
- ↑ US sends water storage tanks, trailer to Fukushima nuclear plant ( Memento from April 15, 2011 on WebCite ) (English). Kyodo News, April 14, 2011, accessed April 15, 2011.
- ↑ a b Seismic Damage Information (the 128th Release), Extract ( Memento from May 11, 2011 on WebCite ) (English). NISA, May 7, 2011.
- ↑ Removing highly toxic water remains difficult task at nuke plant ( Memento from April 15, 2011 on WebCite ) (English). Kyodo News, April 14, 2011, accessed April 15, 2011.
- ↑ a b Earthquake Report - JAIF, No. 58: 20:00, April 20 ( Memento from April 20, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 20, 2011 (PDF; 90 kB)
- ↑ Toshiba proposes decommissioning 4 reactors in 10 years ( Memento from April 9, 2011 on WebCite ) (English). Kyodo News, April 8, 2011, accessed April 8, 2011.
- ↑ a b c Seismic Damage Information (the 95th Release) ( Memento from April 20, 2011 on WebCite ) (English, pdf). NISA, April 15, 2011: "removal of rubble".
- ↑ Earthquake Report - JAIF, No. 249 ( Memento of December 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, October 29, 2011 (PDF; 171 kB)
- ↑ Robotic Exoskeletons from Cyberdyne Could Help Workers Clean Up Fukushima Nuclear Mess (German: Robotic Exoskeletons from Dyberdyne Could Help Workers Eliminate the Fukushima Nuclear Mess) . In: Scientific American . November 9, 2011. Retrieved November 27, 2011.
- ↑ New HAL Exoskeleton: Brain-Controlled Full Body Suit to Be Used In Fukushima Cleanup (German: New HAL Exoskeleton: brain-controlled full body suit for use when cleaning up in Fukushima) . Neurogadget.com. October 18, 2012. Retrieved October 22, 2012.
- ↑ TEPCO tries to enclose high radiation in sea in nuke crisis ( Memento from April 9, 2011 on WebCite ) (English). Kyodo News, April 10, 2011, accessed April 9, 2011.
- ↑ Measures to prevent the spread of liquid including radiactive materials ( Memento from May 12, 2011 on WebCite ) (English, pdf). NISA, April 16, 2011.
- ↑ Information on the situation in Japan . ( Memento from April 15, 2011 on WebCite ) GRS, April 14, 2011.
- ↑ Fukushima Daiichi Nuclear Power Station Unit 2: Countermeasures to stop the outflow of contaminated water and the water amount flowed out into the sea ( Memento from April 21, 2011 on WebCite ) (English). Tepco, April 21, 2011.
- ↑ Earthquake Report - JAIF, No. 54: 18:00, April 16 ( Memento from April 16, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 16, 2011 (PDF; 280 kB)
- ↑ Seismic Damage Information (the 98th Release) ( Memento of April 17, 2011 on WebCite ) (English, pdf). NISA, April 17, 2011.
- ↑ Fukushima: Arge failures in decontamination . ( Memento from April 16, 2011 on WebCite ) pressetext.com, April 7, 2011.
- ↑ Up to 57 millisieverts measured at Nos. 1, 3 reactor buildings (first photo shows INL robots) ( memento from April 18, 2011 on WebCite ). Kyodo News, April 18, 2011, accessed April 18, 2011.
- ↑ INL To Send Robot To Japan ( Memento from April 18, 2011 on WebCite ) (English). Local8 News, Idaho , USA, March 30, 2011.
- ↑ Earthquake Report - JAIF, No. 56: 20:00, April 18 ( Memento from April 18, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 18, 2011 (PDF; 69 kB)
- ↑ Earthquake Report - JAIF, No. 62: 18:00, April 24 ( memento of April 24, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 24, 2011 (PDF; 210 kB)
- ↑ Current Status of Fukushima Daiichi and Fukushima Daini Nuclear Power Station ( Memento June 11, 2011 on WebCite ). Tepco, June 6, 2011: “Introduction of Remote Controlling Machine such as Robots” (p. 12).
- ↑ a b c d e f g h Reactor Core Status of Fukushima Daiichi Nuclear Power Station Unit 1 ( Memento from May 17, 2011 on WebCite ) (PDF). Tepco, May 15, 2011 (PDF; 95 kB).
- ↑ a b c d e Status of cores at Units 2 and 3 in Fukushima Daiichi Nuclear Power Station ( Memento from May 25, 2011 on WebCite ) (English). Tepco, May 24, 2011, accessed May 25, 2011.
- ↑ Agency admits 'melting' of N-fuel ( Memento from May 17, 2011 on WebCite ). Yomiuri Shimbun, April 20, 2011.
- ↑ a b c d e f Earthquake Report - JAIF, No. 79 ( Memento from May 12, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 12, 2011 (PDF; 101 kB)
- ↑ Fukushima: Record radioactivity in reactor 2 measured at 530 Sieverts per hour , Telepolis, February 3, 2017
- ↑ Submission of a report regarding the plant data of Fukushima Daiichi Nuclear Power Station at the time of the earthquake to Nuclear and Industrial Safety Agency, Ministry of Economy, Trade and Industry ( Memento from May 29, 2011 on WebCite ) (English). Tepco, May 16, 2011.
- ↑ 東京 電力 株式会社 か ら 送 付 さ れ た 原子 力 災害 対 策 特別 措置 法 第 10 条 に 基 づ く 通報 資料 等 の 公 表 に つ い て ( Memento from July 22, 2011 in the Internet Archive ) (Article 10 messages from Tepco; Japanese). June 24, 2011, accessed July 5, 2011.
- ↑ a b Roadmap towards Restoration from the Accident at Fukushima Daiichi Nuclear Power Station ( Memento from April 17, 2011 on WebCite ) (English, pdf). Tepco, April 17, 2011 (PDF; 115 kB).
- ↑ a b c Earthquake Report - JAIF, No. 78 ( Memento of May 10, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 11, 2011 (PDF; 120 kB)
- ↑ Stabilizing reactors by year's end may be impossible: Tepco ( Memento from May 29, 2011 on WebCite ) (English). The Japan Times, May 30, 2011.
- ↑ a b Earthquake Report - JAIF, No. 82 ( Memento of May 17, 2011 on WebCite ) (English). May 15, 2011 (PDF; 249 kB)
- ↑ Seismic Damage Information (the 123rd Release), Extract ( Memento from May 2, 2011 on WebCite ) (English, pdf). NISA, May 2, 2011.
- ↑ a b Earthquake Report - JAIF, No. 99 ( Memento from June 1, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 1, 2011 (PDF; 124 kB).
- ↑ a b c d Seismic Damage Information (the 164th Release) ( Memento from June 10, 2011 on WebCite ) (English). NISA, June 9, 2011.
- ↑ Pump failure nearly brings No. 5 to a boil ( Memento from June 10, 2011 on WebCite ) (English). The Japan Times, May 30, 2011.
- ↑ Earthquake Report - JAIF, No. 111 ( Memento from June 13, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 13, 2011 (PDF; 89 kB)
- ↑ a b Summary of radioactive accumulated water treatment system ( Memento from June 10, 2011 on WebCite ) (English, pdf). Tepco, June 9, 2011, accessed June 10, 2011.
- ↑ a b Earthquake Report - No. 123 ( Memento from June 25, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 25, 2011 (PDF; 276 kB)
- ↑ High stakes for cleaning system / New technology could provide big boost to end Fukushima N-plant crisis ( Memento from August 21, 2011 on WebCite ). Yomiuri Shimbun, August 19, 2011. For the week from August 3, the occupancy rate is 77%, but the figure 6,720 results in 80%.
- ↑ a b Earthquake Report - JAIF, No. 101 ( Memento from June 3, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 3, 2011 (PDF; 68 kB).
- ↑ No. 1 reactor vessel damaged 5 hours after quake ( Memento June 6, 2011 on WebCite ). NHK, June 6, 2011, accessed June 6, 2011.
- ↑ 53.1 billion yen needed to clean water ( Memento from May 30, 2011 on WebCite ) (English). Yomiuri Shimbun, May 29, 2011.
- ↑ Earthquake Report - JAIF, No. 149 ( Memento from July 22, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 21, 2011 (PDF; 100 kB)
- ↑ Earthquake Report - JAIF, No. 158 ( Memento from July 30, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 30, 2011 (PDF; 190 kB)
- ↑ Earthquake Report - JAIF, No. 112 ( Memento from June 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 14, 2011, (PDF; 139 kB)
- ↑ Water levels of accumulated water ( Memento from July 2, 2011 on WebCite ) (English, pdf). NISA, June 28, 2011.
- ↑ Water levels of accumulated water ( Memento from July 2, 2011 on WebCite ) (English, pdf). NISA, August 12, 2011.
- ↑ Overview of Radioactive Accumulated Water Treatment System (Additional Installment of 2nd Cesium Adsorption Instrument) ( Memento from August 14, 2011 on WebCite ) (English, pdf). Tepco, August 3, 2011, accessed August 14, 2011.
- ↑ Water levels of accumulated water ( Memento from December 11, 2011 on WebCite ) (English, pdf). NISA, December 5, 2011.
- ↑ Almost 130,000 Cubic Meters of Water Already Treated at Fukushima Daiichi NPS, Making Cold Shutdown of Units 1 to 3 Likely by Year-end ( Memento from December 20, 2011 on WebCite ) (English, pdf). In: Atoms In Japan . JAIF, October 24, 2011 (PDF; 96 kB)
- ↑ Regarding the steps to be taken regarding the leakage of water containing radioactive materials at the water desalination of Fukushima Daiichi Nuclear Power Station ( Memento from December 14, 2011 on WebCite ) (English, pdf). Tepco, December 8, 2011, (PDF; 1.2 MB), accessed December 14, 2011.
- ↑ Temperature diagrams from, and (pdf). Tepco, December 13, 2011, archived by Original 1 ( Memento from January 30, 2012 in the Internet Archive ), Original 2 ( Memento from January 30, 2012 in the Internet Archive ) and Original 3 ( Memento from January 30, 2012 in the Internet Archive ) , accessed December 13, 2011.
- ↑ a b Earthquake Report - JAIF, No. 239 ( Memento of December 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, October 19, 2011 (PDF; 78 kB).
- ↑ Japan gov't declares 'cold shutdown' of crippled Fukushima plant ( Memento from December 16, 2011 on WebCite ) (English). Mainichi Daily News, December 16, 2011, accessed December 16, 2011.
- ^ N-fuel conditions unclear ( Memento of December 16, 2011 on WebCite ). Yomiuri Shimbun, November 19, 2011.
- ↑ Ralf Nestler: Fukushima - island of isotopes. Der Tagesspiegel , June 8, 2013, accessed on October 6, 2016 .
- ↑ a b Fukushima - Radioactive fish caught near nuclear ruins. Welt.de, July 12, 2013, accessed October 6, 2016 .
- ↑ Basic Design of Water Shield Wall at the Seaside ( Memento from December 14, 2011 on WebCite ) (English, pdf). Tepco, August 31, 2011, accessed December 14, 2011.
- ↑ DER SPIEGEL: Fukushima: Recovery of fuel rods from reactor 4 has begun - DER SPIEGEL - science. Retrieved May 19, 2020 .
- ↑ DER SPIEGEL: Fukushima: Tepco pulls fuel rods from the nuclear power plant - DER SPIEGEL - Wissenschaft. Retrieved May 19, 2020 .
- ↑ Earthquake Report - JAIF, No. 291 ( Memento from December 15, 2011 on WebCite ) (English, pdf). JAIF / NHK, December 15, 2011 (PDF; 97 kB)
- ↑ Fukushima: shutdown lasts up to 40 years ( memento of December 23, 2011 on WebCite ). In: heute magazine . ZDF, December 21, 2011, accessed on December 23, 2011.
- ↑ Four years later - the clearance of the Fukushima power plant is delayed. In: srf.ch . December 27, 2019, accessed December 27, 2019 .
- ↑ a b c d e f g h i j k l m n o p q r s t u v The 2011 off the Pacific coast of Tohoku Pacific Earthquake and the seismic damage to the NPPs ( Memento from April 13, 2011 on WebCite ) (English, pdf). NISA, April 4, 2011. Graphic on the location and flooding of the diesel generators (“D / G”) on p. 12 (document numbering, different from the PDF time numbers); Emergency cooling system block 1 including flooding of the batteries on page 17f; Course in reactor 1 on p. 15 f., In reactor 2 on p. 24 f., In reactor 3 on p. 28 f .; Pressures are given relative to the external pressure; 100 kPa must be added for the absolute pressure
- ↑ Inga Maren Tragsdorf: Development and investigation of catalyst elements for innovative hydrogen recombiners . In: Forschungszentrum Jülich (Ed.): Energietechnik / Energy Technology series . Volume 36, 2004, ISBN 3-89336-384-X , ISSN 1433-5522 , pp. 1 ( p. 10 PDF, 6 MB ).
- ↑ a b c What is a meltdown? . ( Memento from April 11, 2011 on WebCite ) Society for Plant and Reactor Safety , March 18, 2011.
- ↑ a b Arjun Makhijani: Possible consequences of the accident in the Fukushima nuclear plant ( Memento from April 1, 2011 on WebCite ) (pdf). In: ippnw.de . (PDF; 129 kB), accessed on April 2, 2011. Summary of the paper “Post ‐ Tsunami Situation at the Fukushima Daiichi Nuclear Power Plant in Japan”.
- ↑ P. Kuan, DJ Hanson and F. Odar: Managing water addition to a degraded core , 1992, pp. 3–5.
- ↑ a b c d e f g h チ ャ ー ト 3 号 機 (analog data recording from block 3) ( Memento from May 21, 2011 on WebCite ) (Japanese). Tepco, May 16, 2011, accessed on May 20, 2011. Water level and pressure curve on page 11ff, further pressure measurements on page 17ff; automatic pressure relief from the pressure vessel into the safety container can be recognized as peaks in the green line. Reactor temperatures on p. 53 f.
- ↑ a b Outline regarding management of Fukushima Daiichi Unit 3 ( Memento from May 27, 2011 on WebCite ). Kantei, March 13, 2011.
- ↑ a b Dave Lochbaum: Possible Cause of Reactor Building Explosions ( Memento from May 8, 2011 on WebCite ) (English). In: All Things Nuclear . Union of Concerned Scientists, March 18, 2011.
- ↑ Roark Wolfe: Energy Industry Mechanical Engineer on Fukushima ( Memento of May 8, 2011 on WebCite ) (English). March 18, 2011.
- ↑ One crisis after another harried TEPCO's response ( Memento from May 14, 2011 on WebCite ) (English). Yomiuri Shimbun, April 14, 2011.
- ^ US Experts Blame Fukushima 1 Explosions and Radiation on Failed Venting System , New York Times (March 25, 2011), accessed April 8, archived April 8: p. 1 ( memento of April 8, 2011 on WebCite ), P. 2 ( memento of April 8, 2011 on WebCite )
- ↑ TEPCO says venting failure caused hydrogen explosion at No. 1 reactor ( memento from June 5, 2011 on WebCite ). The Mainichi Daily News, June 4, 2011, accessed June 6, 2011.
- ↑ JAIF Reactor Status and Major Events Update 12 - NPPs in Fukushima as of 16:00 March 18 ( Memento from April 12, 2011 on WebCite ) (English, pdf). Japan Atomic Industrial Forum, March 18, 2011 (PDF; 252 kB)
- ↑ Turn the winds and let Tokyo breathe easy . ( Memento from April 12, 2011 on WebCite ) NZZ, March 17, 2011.
- ↑ The catastrophe of the century in Japan - live ticker . ( Memento from May 2, 2011 on WebCite ) stern.de, March 17, 2011: "On board there are 95 tons of the chemical boron, which is supposed to slow down the reaction on the fuel rods."
- ↑ a b c Report regarding the implementation of a measure to flood primary containment vessel to the upper area of fuel reange in Unit 1 of Fukushima Daiichi Nuclear Power Station (summary) ( Memento from May 5, 2011 on WebCite ) (English, pdf) . Tepco, May 5, 2011 (PDF; 119 kB).
- ↑ a b Earthquake Report - JAIF, No. 81 ( Memento from May 17, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 14, 2011 (PDF; 227 kB).
- ↑ Flooding and ventilating the reactor . ( Memento from May 17, 2011 on WebCite ) Neue Zürcher Zeitung, March 15, 2011.
- ^ A b Christoph Behrens: Coincidence prevented fuel rods from exploding in Fukushima , Süddeutsche Zeitung of May 24, 2016, accessed on May 24, 2016.
- ↑ Mari Yamaguchi, Jeff Donn: Japan quake causes emergencies at 5 nuke reactors ( Memento from April 7, 2014 in the Internet Archive ) (English). In: thejakartapost.com . Associated Press, March 11, 2011, accessed March 13, 2011.
- ↑ Terror at N-plant during quake ( Memento from May 14, 2011 on WebCite ) (English). Yomiuri Shimbun, March 17, 2011.
- ↑ a b c d e f Analysis and evaluation of the operation record and accident record of Fukushima Daiichi Nuclear Power Station at the time of Tohoku-Chihou-Taiheiyou-Oki-Earthquake (summary) ( Memento from May 25, 2011 on WebCite ) ( English). Tepco, May 24, 2011, (PDF; 47 kB), accessed on May 25, 2011.
- ↑ Earthquake Report - No. 90 ( Memento from May 23, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 23, 2011 (PDF; 100 kB)
- ↑ a b Plant Data of Fukushima Daiichi Nuclear Power Station ( Memento from May 21, 2011 on WebCite ) (English). Tepco, May 17, 2011, accessed May 20, 2011.
- ↑ チ ャ ー ト 1 号 機 (analog data recording from block 1) ( Memento from May 20, 2011 on WebCite ) (Japanese). Tepco, May 16, 2011, accessed on May 20, 2011. Water level indicator on page 5f, pressure fluctuations on page 7f.
- ↑ a b Occurrence of a Specific Incident Stipulated in Article 15, Clause 1 of the Act on Special Measures Concerning Nuclear Emergency Preparedness (Fukushima Daiichi) ( Memento from April 25, 2011 on WebCite ) (English). Tepco, March 11, 2011.
- ↑ Nuclear Crisis at Fukushima ( Memento from April 28, 2011 on WebCite ) (English). In: All Things Nuclear . Union of Concerned Scientists , March 11, 2011.
- ↑ a b c d e f g Kohta Juraku: Chronological outline of the nuclear accidents in Japan ( Memento of April 28, 2011 on WebCite ) (English). University of Tokyo / Berkeley Nuclear Research Center.
- ↑ a b c d e f g h i Seismic Damage Information (the 57th Release) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 27, 2011.
- ↑ a b c d e f g h i プ ラ ン ト 関 連 パ ラ メ ー タ 数 表 デ ー タ (table of system parameters) ( Memento from May 19, 2011 on WebCite ) (Japanese). Tepco, May 16, 2011, accessed May 19, 2011.
- ↑ a b Fukushima Insider: Not a tsunami, but an earthquake is said to have ruined nuclear power plants. ( Memento from May 19, 2011 on WebCite ) Spiegel Online, May 16, 2011.
- ↑ Results of Calculations by the System for Prediction of Environmental Emergency Dose Information (SPEEDI) ( Memento from May 12, 2011 on WebCite ) (English, pdf). NISA, May 3, 2011.
- ↑ Venting simulation ( Memento from May 12, 2011 on WebCite ) (Japanese, pdf). NSC / NISA, March 11, 2011.
- ↑ a b c Seismic Damage Information (the 11th Release) . ( Memento from April 27, 2011 on WebCite ) NISA, March 12, 2011.
- ^ Radiation Level Rising In Fukushima Nuclear Plant Turbine Building ( Memento from May 14, 2011 on WebCite ), Nikkei.com, March 12, 2011, accessed May 14, 2011.
- ↑ Nuclear Crisis: How It Happened / Hydrogen blasts at plant surprised experts ( Memento June 11, 2011 on WebCite ) (English). Yomiuri Shimbun, June 10, 2011.
- ↑ a b c TEPCO workers 'frantic' over vents ( Memento from June 23, 2011 on WebCite ) (English). Yomiuru Shimbun, June 20, 2011.
- ↑ Dose rate values of Fukushima Daiichi before the accident ( memento of March 24, 2011 on WebCite ) (Japanese). Tepco, accessed March 24, 2011.
- ↑ Reiji Yoshida: Tepco report reveals lack of preparedness ( Memento from June 20, 2011 on WebCite ) (English). The Japan Times, June 20, 2011.
- ↑ Damage from mega quake increasing, death toll feared to top 1,800 ( Memento from April 1, 2011 on WebCite ) (English). Kyodo News, March 13, 2011, accessed April 2, 2011.
- ↑ a b Nuclear Crisis: How It Happened / Kan's visit 'wasted time' ( Memento from June 11, 2011 on WebCite ) (English). Yomiuri Shimbun, June 9, 2011.
- ↑ a b c d e TEPCO failures multiply / Compounding of missteps exacerbated nuclear crisis ( Memento from May 17, 2011 on WebCite ) (English). Yomiuri Shimbun, April 2, 2011.
- ↑ a b Results of Monitoring at Fukushima Daiichi Nuclear Power Station ( Memento from May 29, 2011 on WebCite ) (English). Tepco, May 28, 2011, accessed June 10, 2011.
- ↑ a b c Sequence of Developments at Nuclear Power Stations Affected by the Earthquake ( Memento from March 20, 2011 on WebCite ) (English, pdf). JAIF, March 18, 2011, accessed March 20, 2011.
- ↑ Хронология вебкамеры на японскую АЭС "Фукусима-1" (webcam chronology of the Japanese nuclear power plant "Fukuschima-1") (Russian). libres, March 12, 2011, accessed on May 16, 2011. Archived as a copy ( Memento from May 17, 2011 on WebCite ) on May 17, 2011. From this perspective, the block 1/2 chimney is behind the middle one (block -3 / 4-) chimney and appears a little lower.
- ↑ Occurrence of a Specific Incident Stipulated in Article 15, Clause 1 of the Act on Special Measures Concerning Nuclear Emergency Preparedness (Extraordinary increase of radiation dose at site boundary) ( Memento from April 23, 2011 on WebCite ). Tepco, April 12, 2011.
- ^ Nuclear Power Stations' Response to the Off the Pacific Coast of Tohoku Earthquake ( Memento of May 4, 2011 on WebCite ) (English, pdf). Japan Nuclear Technology Institute, May 1, 2011 (PDF; 698 kB): "Due to the radiation dose at the site's boundary exceeding the criteria (500μSv / h)".
- ↑ a b c The Time-line Regarding Seawater Injection to Unit 1 at Fukushima Daiichi Nuclear Power Station ( Memento from May 26, 2011 on WebCite ) (English). Tepco, May 26, 2011.
- ↑ a b c Gov't briefly stopped TEPCO's seawater injection a day after quake ( Memento from May 21, 2011 on WebCite ) (English). InvestorPoint / Kyodo News, May 20, 2011.
- ↑ a b TEPCO fax about seawater not passed to Kan for hours ( Memento from May 26, 2011 on WebCite ) (English). Yomiuri Shimbun, May 26, 2011.
- ↑ a b c d e f g The Status of Alternative Water Injection into Units 1 Through 3, Using the Fire Extinguishing System ( Memento from December 11, 2011 on WebCite ) (English, pdf). NISA, September 16, 2011.
- ↑ Various NISA studies speak of 3:36 pm, but the radiation measurements indicate an explosion before 3:30 pm. NISA sometimes confuses the reporting times with the event times.
- ↑ Chico Harlan and Steven Mufson: Japanese nuclear plants' operator scrambles to avert meltdowns ( Memento from April 12, 2011 on WebCite ) (English). The Washington Post, March 13, 2011.
- ↑ Video of the explosion of Block 1 of Fukushima I on Youtube ( Memento from February 24, 2013 in the Internet Archive )
- ↑ Fukushima Nuclear Accident Update Log: Fukushima Nuclear Accident Update (13 March 2011, 02:35 CET) - Corrected ( Memento from April 12, 2011 on WebCite ). IAEA, March 13, 2011.
- ↑ Explosion did not occur at Fukushima reactor: Japan spokesman ( Memento from April 12, 2011 on WebCite ) (English). Kyodo News, March 12, 2011, accessed March 12, 2011.
- ↑ Earthquake Report - JAIF, No. 64: 20:00, April 26 ( Memento from April 27, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 26, 2011 (PDF; 91 kB)
- ↑ Earthquake Report - JAIF, No. 177 ( Memento of August 21, 2011 on WebCite ) (English, pdf). JAIF / NHK, August 18, 2011 (PDF; 80 kB): "TEPCO never expected hydrogen explosions: report"
- ↑ Minutes - Japan under the sign of catastrophe . ( Memento from May 4, 2011 on WebCite ) spiegel.de, March 12, 2011.
- ↑ Battle to stabilize earthquake reactors ( Memento from May 20, 2011 on WebCite ) (English). World Nuclear News, March 12, 2011.
- ↑ Japan struggles with nuclear reactors in wake of quake ( Memento from April 12, 2011 on WebCite ) (English). CNN, March 13, 2011.
- ↑ a b c Seismic Damage Information (the 26th Release) ( Memento from April 11, 2011 on WebCite ) (English, pdf). NISA, March 16, 2011.
- ^ Fukushima Nuclear Accident Update Log ( Memento April 30, 2011 on WebCite ). IAEA, March 14, 2011: “powered by mobile power generators”.
- ↑ a b Japanese nuclear plants' operator scrambles to avert meltdowns ( Memento from April 11, 2011 on WebCite ) (English). The Washington Post, March 13, 2011: " ... a meltdown could be underway at that reactor, Fukushima Daiichi's unit 3, and ... it was" highly possible "that a meltdown was underway at Fukushima Daiichi's unit 1 reactor ".
- ↑ Live ticker Japan . ( Memento from April 26, 2011 on WebCite ) Welt Online, March 15 to 16, 2011.
- ↑ a b The data of Unit 1 to 3 of Fukushima Daiichi Nuclear Power Station measured by CAMS and erratum sheet of core damage ratio ( Memento from April 27, 2011 on WebCite ) (English, pdf). Tepco, April 27, 2011 (PDF; 51 kB).
- ↑ a b c Хронология вебкамеры на японскую АЭС "Фукусима-1" (webcam chronology of the Japanese nuclear power plant "Fukuschima-1") (Russian). libres, March 15, 2011, accessed May 16, 2011. Archived as a copy ( Memento May 17, 2011 on WebCite ) on May 17, 2011.
- ↑ Stabilization at Fukushima Daiichi ( Memento from April 12, 2011 on WebCite ) (English). World Nuclear News, March 20, 2011.
- ↑ a b c d e Seismic Damage Information (the 73rd Release) ( Memento from April 11, 2011 on WebCite ) (English, pdf). NISA, April 4, 2011.
- ↑ Earthquake Report - JAIF, No. 103 ( Memento from June 6, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 5, 2011, (PDF; 231 kB).
- ↑ Injection of nitrogen to reactor containment vessel of Fukushima Daiichi Nuclear Power Station Unit 1 ( Memento from April 12, 2011 on WebCite ). Tepco, April 6, 2011.
- ↑ Nitrogen injected into Fukushima reactor to reduce risk of explosion ( Memento from April 12, 2011 on WebCite ). Kyodo News, accessed April 6, 2011.
- ↑ Tokyo Electric admits fuel could be melting at Fukushima nuke plant ( Memento from April 21, 2011 on WebCite ). Kyodo News, April 21, 2011, accessed April 21, 2011.
- ↑ Earthquake Report - JAIF, No. 66 ( Memento of April 29, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 28, 2011 (PDF; 117 kB), accessed on April 29, 2011.
- ↑ a b Improvement of the environment within the Reactor Building of Unit 1 ( Memento from May 5, 2011 on WebCite ) (English, pdf). Tepco, May 4, 2011 (PDF; 350 kB).
- ↑ a b c Earthquake Report - JAIF, No. 80 ( Memento of May 13, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 13, 2011 (PDF; 130 kB).
- ↑ Observed result of leakage in the Reactor Building (Unit 1) ( Memento from May 17, 2011 on WebCite ) (English, pdf). NISA, May 15, 2011.
- ↑ a b Earthquake Report - JAIF, No. 95 ( Memento from May 28, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 28, 2011 (PDF; 276 kB).
- ↑ Earthquake Report - JAIF, No. 96 ( Memento from May 29, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 29, 2011 (PDF; 188 kB).
- ↑ Earthquake Report - JAIF, No. 170 ( Memento from August 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, August 8, 2011 (PDF; 68 kB).
- ↑ Earthquake Report - JAIF, No. 125 ( Memento from June 27, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 27, 2011 (PDF; 109 kB).
- ↑ Regarding Installment of the Reactor Building Cover and Accessory Equipment at Fukushima Daiichi Nuclear Power Station Unit 1 ( Memento from June 26, 2011 on WebCite ) (English, pdf). Tepco, June 23, 2011, (PDF; 328 kB), accessed on June 26, 2011.
- ↑ Earthquake Report - JAIF, No. 237 ( Memento of October 28, 2011 on WebCite ) (English, pdf). JAIF / NHK, October 17, 2011 (PDF; 91 kB).
- ↑ Earthquake Report - JAIF, No. 180 ( Memento of August 21, 2011 on WebCite ) (English, pdf). JAIF / NHK, August 21, 2011 (PDF; 170 kB).
- ↑ Earthquake Report - JAIF, No. 219 ( Memento of October 28, 2011 on WebCite ) (English, pdf). JAIF / NHK, September 28, 2011 (PDF; 66 kB).
- ↑ Earthquake Report - JAIF, No. 229 ( Memento of December 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, October 9, 2011 (PDF; 167 kB).
- ↑ Melted nuclear fuel eroded reactor container by up to 65 cm: TEPCO ( Memento from November 30, 2011 on WebCite ) (English). The Mainichi Daily News, November 30, 2011, accessed November 30, 2011.
- ↑ a b 過渡 現象 記録 装置 デ ー タ 2 号 機 (Short-term data recording block 2) ( Memento from May 21, 2011 on WebCite ) (Japanese). Tepco, May 16, 2011, accessed on May 21, 2011. Failure of diesel generators on p. 30; RCICS on p. 28 (previously also briefly in operation until the required level is reached).
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station (as of 0AM March 12th) . ( Memento from May 10, 2011 on WebCite ) Tepco, March 12, 2011.
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station (as of 11AM March 12th) ( Memento of May 10, 2011 on WebCite ) (English). Tepco, March 12, 2011.
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station (as of 8PM March 12th) ( Memento of May 10, 2011 on WebCite ) (English). Tepco, March 12, 2011.
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station (as of 9am March 13th) ( Memento from May 14, 2011 on WebCite ) (English). Tepco, March 13, 2011.
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station (as of 0pm March 13th) ( Memento of May 10, 2011 on WebCite ) (English). Tepco, March 13, 2011.
- ^ Seismic Damage Information (the 20th Release) . ( Memento of May 5, 2011 on WebCite ) NISA, March 13, 2011: "For Unit 2: Electric Power Source secured, Water Injection Function has been maintained."
- ↑ New fire reported at nuclear plant as Japan races to avert catastrophe ( Memento from May 27, 2011 on WebCite ) (English). The Washington Post, March 15, 2011.
- ↑ Occurrence of a Specific Incident (Failure of reactor cooling function) Stipulated in Article 15, Clause 1 of the Act on Special Measures Concerning Nuclear Emergency Preparedness ( Memento from April 23, 2011 on WebCite ). Tepco, April 14, 2011.
- ↑ The crucial valve in the Fukushima reactor is stuck . ( Memento April 30, 2011 on WebCite ) Welt Online, March 14, 2011.
- ↑ Fuel rods fully exposed again at Fukushima nuclear power plant ( Memento from May 15, 2011 on WebCite ). Xinhua News Agency, March 14, 2011.
- ↑ Earthquake Report - JAIF, No. 6 ( Memento of April 28, 2011 on WebCite ) (English, pdf). JAIF, March 15, 2011 (PDF; 27 kB).
- ↑ Risk of meltdown increases at Japan nuclear reactor ( Memento from May 14, 2011 on WebCite ). Los Angeles Times, March 14, 2011.
- ↑ Seismic Damage Information (the 47th Release) (As of 08:00 March 24th, 2011) ( Memento from May 6, 2011 on WebCite ) (English, pdf). NISA, March 24, 2011.
- ↑ Status of nuclear power plants in Fukushima as of 22:00 March 18 (Estimated by JAIF) ( Memento from May 6, 2011 on WebCite ) (English, pdf). March 18, 2011 (PDF; 226 kB).
- ↑ a b Plant Status of Fukushima Daiichi Nuclear Power Station (as of 3:00 pm, April 28) ( Memento from April 29, 2011 on WebCite ) (English). Tepco, April 28, 2011.
- ↑ Earthquake Report - JAIF, No. 276 ( Memento of December 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, November 29, 2011 (PDF; 77 kB).
- ↑ Seismic Damage Information (the 29th Release) (As of 06:30 March 18th, 2011) ( Memento of May 8, 2011 on WebCite ) (English, pdf). NISA, March 18, 2011: "White smoke continues to be generated from the Blow-out Panel of reactor building."
- ↑ Japan: Status report from March 16, 2011, 6:00 a.m. (CET) . ( Memento from April 1, 2011 on WebCite ) Society for Plant and Reactor Safety, March 16, 2011.
- ↑ Core of Stricken Reactor Probably Leaked, US Says ( April 21, 2011 memento on WebCite ). New York Times, April 6, 2011.
- ↑ Seismic Damage Information (the 28th Release) ( Memento of April 11, 2011 on WebCite ) (English, pdf). NISA, March 18, 2011.
- ^ Fukushima Nuclear Accident Update Log . IAEA, March 24, 2011, accessed May 7, 2011.
- ↑ a b c d e Seismic Damage Information (the 36th Release) (As of 16:30 March 20th, 2011) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 20, 2011.
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station (as of 0:00 PM Mar 19th) ( Memento from May 14, 2011 on WebCite ) (English). Tepco, March 19, 2011.
- ↑ Control room for Unit 2 of Fukushima Daiichi Nuclear Power Station (pictured on March 26, 2011) . ( Memento from April 29, 2011 on WebCite ) Tepco, March 26, 2011.
- ↑ a b Photos For Press ( Memento from April 29, 2011 on WebCite ) (English). Tepco.
- ↑ Earthquake Report No. 32 (JAIF) ( Memento from April 12, 2011 on WebCite ) (English, pdf). JAIF / NHK, March 27, 2011 (PDF; 32 kB).
- ↑ At Plant, a Choice Between Bad, Worse ( Memento from May 11, 2011 on WebCite ) (English). Wall Street Journal, March 30, 2011: “Authorities say 1,000 millisieverts is the upper limit of their measuring devices”.
- ↑ Radioactive water at No. 2 reactor due to partial meltdown: Edano ( Memento from April 12, 2011 on WebCite ). Kyodo News, March 28, 2011, accessed March 28, 2011.
- ↑ Horizontal map of the cable duct (orange) at Block 2 ( Memento from April 4, 2011 on WebCite ) (English, pdf). Tepco / NISA.
- ↑ a b Vertical map of the cable duct (orange) at Block 2 ( Memento from April 4, 2011 on WebCite ) (English, pdf). Tepco / NISA.
- ↑ Out flow of fluid containing radioactive materials to the ocean from areas near intake channel of Fukushima Daiichi Nuclear Power Station Unit 2 ( Memento from April 12, 2011 on WebCite ) (English). Tepco, April 2, 2011.
- ↑ Workers struggle to plug leak at Japan nuclear plant ( Memento from April 12, 2011 on WebCite ). CNN, April 2, 2011.
- ↑ Absorbent yet to soak up radioactive water at Fukushima plant ( Memento from April 12, 2011 on WebCite ) (English). Kyodo News, April 3, 2011, accessed April 4, 2011.
- ^ Highly radioactive water leaking into sea stops: TEPCO . ( Memento from April 12, 2011 on WebCite ) Kyodo News, April 6, 2011, accessed April 6, 2011.
- ↑ TEPCO begins building steel wall, fence to prevent sea contamination ( Memento from April 12, 2011 on WebCite ) (English). Kyodo News, April 9, 2011, accessed April 9, 2011.
- ^ Result of Water Analysis in the Skimmer Surge Tank of Fukushima Daiichi Nuclear Power Station Unit 2 ( Memento from April 18, 2011 on WebCite ) (English, pdf). Tepco, April 17, 2011 (PDF; 8 kB).
- ↑ a b c d Earthquake Report - JAIF, No. 57: 20:00, April 19 ( Memento from April 22, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 19, 2011 (PDF; 162 kB).
- ↑ a b Earthquake Report - JAIF, No. 59: 20:00, April 21 ( Memento from April 21, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 21, 2011 (PDF; 79 kB).
- ↑ Water levels of stagnant water ( Memento from May 7, 2011 on WebCite ) (English, pdf). NISA, May 5, 2011.
- ↑ Earthquake Report - JAIF, No. 119 ( Memento from June 22, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 21, 2011 (PDF; 101 kB).
- ↑ a b c Earthquake Report - JAIF, No. 121 ( Memento from June 24, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 23, 2011 (PDF; 99 kB).
- ↑ Seismic Damage Information (the 184th Release), Extract ( Memento from June 30, 2011 on WebCite ) (English, pdf). NISA, June 29, 2011
- ↑ Seismic Damage Information (the 257th Release), Extract ( Memento from November 2, 2011 in the Internet Archive ) (English, pdf). NISA, September 15, 2011.
- ↑ Earthquake Report - JAIF, No. 205 ( Memento of December 11, 2011 on WebCite ) (English, pdf). JAIF / NHK, September 15, 2011 (PDF; 67 kB).
- ↑ Earthquake Report - JAIF, No. 258 ( Memento of December 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, November 7, 2011 (PDF; 67 kB).
- ↑ Jaif Report 385 of March 27, 2012 ( Memento of June 16, 2013 in the Internet Archive ) (PDF; 136 kB). Retrieved March 27, 2012.
- ↑ Only two inches of water in reactor two. In: Frankfurter Allgemeine Zeitung , March 27, 2012. Retrieved March 27, 2012.
- ↑ Little water in Fukushima-1 reactor. In: Süddeutsche Zeitung , March 28, 2012. Accessed March 28, 2012.
- ↑ Record radioactivity in reactor 2. Accessed February 3, 2017 .
- ↑ a b 過渡 現象 記録 装置 デ ー タ 3 号 機 (Short-term data recording block 3) ( Memento from May 21, 2011 on WebCite ) (Japanese). Tepco, May 16, 2011. RCIC on p. 6, diesel generators on p. 11 f.
- ↑ Japan's Fukushima nuclear plant faces new reactor problem ( Memento from April 12, 2011 on WebCite ) (English). Reuters, March 12, 2011.
- ↑ Occurrence of a Specific Incident Stipulated in Article 15, Clause 1 of the Act on Special Measures Concerning Nuclear Emergency Preparedness ( Memento of April 23, 2011 on WebCite ). Tepco, April 13, 2011.
- ↑ Efforts to manage Fukushima Daiichi 3 ( Memento from May 14, 2011 on WebCite ) (English). World Nuclear News, March 14, 2011.
- ^ Yukio Edano: Press Conference by the Chief Cabinet Secretary ( Memento of May 27, 2011 on WebCite ) (English). Kantei, March 13, 2011: "... the water injection situation grew unstable, and the water level dropped."
- ↑ The Status of Units 1 Through 3 Venting ( Memento December 11, 2011 on WebCite ) (English, pdf). NISA, September 16, 2011, accessed December 12, 2011.
- ↑ a b c d e f NISA Seismic Damage Information (the 30th Release) (As of 15:00 March 18th, 2011) ( Memento from May 2, 2011 on WebCite ) (English, pdf). Nuclear and Industrial Safety Agency (NISA), March 18, 2011.
- ↑ Japan Fukushima explosion of reactor 3 (video) . ( Memento of February 24, 2013 in the Internet Archive ) YouTube, March 14, 2011, accessed on March 19, 2011.
- ↑ White smoke around the Fukushima Daiichi Nuclear Power Station Unit 3 (3rd release) ( Memento from April 12, 2011 on WebCite ) (English). Tepco, March 14, 2011.
- ↑ a b Andrew Gilligan and Robert Mendick: Japan tsunami: Fukushima Fifty, the first interview ( Memento from April 8, 2011 on WebCite ) (English). The Telegraph, March 27, 2011: "The six of them are now dead, buried under flying concrete."
- ↑ a b Aerial photo of blocks 1 to 4 . ( Memento from May 8, 2011 on WebCite ) Air Photo Service Co. Ltd., Japan, March 20, 2011. Block 3 in the middle of the picture, Block 1 on the left edge of the picture.
- ↑ Earthquake Report - No. 89 ( Memento from May 23, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 22, 2011 (PDF; 203 kB).
- ^ Gundersen Postulates Unit 3 Explosion May Have Been Prompt Criticality in Fuel Pool. Archived from the original on April 30, 2011 ; Retrieved November 18, 2012 . (English, video). Fairewinds Associates, April 26, 2011, accessed May 11, 2011.
- ↑ a b Status of nuclear power plants in Fukushima as of 22:00 March 20 ( Memento from April 12, 2011 on WebCite ) (English). JAIF, March 20, 2011 (PDF; 279 kB.
- ↑ US drone to examine Fukushima nuclear power plant . ( Memento from April 25, 2011 on WebCite ) NZZ, March 16, 2011.
- ↑ Fukushima: Helicopters and water cannons are supposed to cool reactors . ( Memento from April 12, 2011 on WebCite ) In: Zeit Online . March 17, 2011.
- ↑ Military water cannons end their use in Fukushim . ( Memento from April 25, 2011 on WebCite ) In: stern.de . March 17, 2011.
- ↑ a b Helicopters end their mission over the Fukushima nuclear power plant . ( Memento from May 2, 2011 on WebCite ) Neue Zürcher Zeitung, March 17, 2011.
- ↑ Tepco calls the delete operation successful . ( Memento from May 2, 2011 on WebCite ) Zeit Online, March 17, 2011.
- ^ Seismic Damage Information (the 45th Release) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 23, 2011.
- ↑ Seismic Damage Information (the 38th Release) ( Memento April 12, 2011 on WebCite ) (English, pdf). NISA, March 21, 2011.
- ↑ Status of nuclear power plants in Fukushima as of 16:00 March 21 ( Memento from April 12, 2011 on WebCite ) (English, pdf). JAIF, March 21, 2011 (PDF; 229 kB).
- ↑ Grayish smoke seen billowing from Fukushima No. 3 reactor building ( Memento from April 12, 2011 on WebCite ). Kyodo News, March 21, 2011, accessed March 21, 2011.
- ↑ White smoke at Fukushima No. 2 reactor, smoke at No. 3 reactor stops ( Memento from April 12, 2011 on WebCite ). Kyodo News, March 21, 2011, accessed March 21, 2011.
- ↑ Seismic Damage Information (the 40th Release (corrected)) (As of 21:00 March 21st, 2011) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 21, 2011.
- ↑ Dose rates measured at selected measuring points Fukushima Daiichi ( Memento from May 10, 2011 on WebCite ) (pdf). GRS, March 23, 2011 (PDF; 211 kB).
- ↑ a b Seismic Damage Information (the 46th Release) (As of 19:00 March 23rd, 2011) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 23, 2011.
- ↑ Control room for Unit 3 of Fukushima Daiichi Nuclear Power Station (pictured on March 22, 2011) . ( Memento from April 29, 2011 on WebCite ) Tepco, March 24, 2011.
- ↑ a b Earthquake Report No. 27 (JAIF) ( Memento of April 11, 2011 on WebCite ) (English, pdf). JAIF / NHK, March 24, 2011 (PDF; 31 kB).
- ↑ Measured values of the contaminated water in the basement of Block 3 ( Memento from March 25, 2011 on WebCite ) (English, pdf). NISA, March 26, 2011, accessed March 25, 2011.
- ↑ Japan reactor core may be leaking radioactive material, official says ( Memento from May 15, 2011 on WebCite ). CNN, March 25, 2011.
- ↑ High-level radiation suspected to be leaking from No. 3 reactor's core ( memento from April 12, 2011 on WebCite ). Kyodo Nows, March 25, 2011; accessed March 26, 2011.
- ↑ Seismic Damage Information (the 65th Release) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 31, 2011.
- ↑ Survey map of Fukushima Daiichi Nuclear Power Station as of 17:20 on April 23, 2011 ( Memento from April 30, 2011 on WebCite ) (English, pdf). March 23, 2011 (PDF; 620 kB): "concrete pumping vehicle called" Elephant "".
- ↑ Progress Status of “Roadmap towards Restoration from the Accident at Fukushima Daiichi Nuclear Power Station” ( Memento from May 22, 2011 on WebCite ) (English). Tepco, May 17, 2011, (PDF; 109 kB), accessed on May 22, 2011.
- ↑ Seismic Damage Information (the 115th Release), Extract ( Memento from April 27, 2011 on WebCite ) (English, pdf). NISA, April 26, 2011.
- ↑ Fukushima Dai-ichi Nuclear Power Station - Unit 3 Parameters Related to Temperature ( Memento from May 11, 2011 on WebCite ) (English, pdf). NISA, May 11, 2011
- ↑ a b Earthquake Report - JAIF, No. 77 ( Memento of May 10, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 10, 2011 (PDF; 134 kB).
- ↑ 福島 第一 原子 力 発 電 所 温度 に 関 す る パ ラ メ ー タ (temperature data from the Fukushima Daiichi nuclear power plant) ( Memento from May 23, 2011 on WebCite ) (Japanese). METI , May 22, 2011.
- ↑ Status of the Spent Fuel Pool of Unit 3 of Fukushima Daiichi Nuclear Power Station (30MByte) ( Memento from June 2, 2011 in the Internet Archive ) (ZIP / M1V video). Tepco, May 8, 2011, accessed May 17, 2011.
- ↑ Possibility of leakage of radioactive water off the site near the water intake canal of Unit 3 of Fukushima Daiichi Nuclear Power Station (continued report) ( Memento from May 11, 2011 on WebCite ). Tepco, May 11, 2011.
- ↑ Seismic Damage Information (the 165th Release) ( Memento from July 5, 2011 on WebCite ) (English, pdf). NISA, June 10, 2011.
- ↑ 2011.06.14 00: 00-01: 00 / 福島 原 発 ラ イ ブ カ メ ラ (Live Fukushima Nuclear Plant Cam) (Video). In: Youtube . Tepco, June 14, 2011, accessed July 1, 2011.
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station ( Memento from May 28, 2011 on WebCite ) (English). Tepco, May 28, 2011.
- ↑ a b Earthquake Report - JAIF, No. 114 ( Memento from June 16, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 16, 2011 (PDF; 90 kB).
- ↑ Earthquake Report - JAIF, No. 124 ( Memento of July 5, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 26, 2011 (PDF; 193 kB).
- ↑ a b Earthquake Report - JAIF, No. 143 ( Memento from July 15, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 15, 2011 (PDF; 130 kB).
- ↑ Earthquake Report - JAIF, No. 132 ( Memento of July 5, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 4, 2011 (PDF; 89 kB).
- ^ Seismic Damage Information (the 244th Release), Extract ( Memento from December 11, 2011 on WebCite ) (English, pdf). NISA, August 31, 2011.
- ^ Mari Yamaguchi: Fukushima: Underwater robot discovers suspected melted nuclear fuel at reactor. In: Independent.co.uk. 23rd July 2017.
- ↑ a b JAIF Reactor Status and Major Events Update 16 - NPPs in Fukushima as of 22:00 March 19 ( Memento from April 12, 2011 on WebCite ) (English, pdf). Japan Atomic Industrial Forum, March 19, 2011 (PDF; 253 kB)
- ↑ Spent nuke fuel pool may be boiling, further radiation leak feared ( Memento of March 31, 2011 on WebCite ). Kyodo News, March 15, 2011, accessed March 31, 2011.
- ↑ Status of nuclear power plants in Fukushima as of 16:00 March 27 (Estimated by JAIF) ( Memento from April 22, 2011 on WebCite ) (English, pdf). March 27, 2011 (PDF; 276 kB). P. 4
- ↑ Damage to the Unit 4 Nuclear Reactor Building at Fukushima Dai-ichi Nuclear Power Station ( Memento from March 31, 2011 on WebCite ) (English). Tepco, March 15, 2011, accessed March 31, 2011.
- ↑ Status of the Spent Fuel Pool of Unit 4 of Fukushima Daiichi Nuclear Power Station ( Memento from June 2, 2011 in the Internet Archive ) (ZIP / M1V video). Tepco, May 8, 2011, accessed May 17, 2011.
- ↑ a b The result of the analysis of the water in the spent fuel pool of Unit 4 of Fukushima Daiichi Nuclear Power Station ( Memento from April 14, 2011 on WebCite ) (English, pdf). Tepco, April 14, 2011 (PDF; 9 kB).
- ↑ Earthquake Report - JAIF, No. 262 ( Memento from December 19, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 16, 2011 (PDF; 57 kB).
- ↑ Conditions of Fukushima Dai-ichi Nuclear Power Station (As of 6:00 May 8, 2011) ( Memento of May 8, 2011 on WebCite ) (English, pdf). NISA, May 8, 2011.
- ↑ Earthquake Report - JAIF, No. 83 ( Memento from May 17, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 16, 2011 (PDF; 98 kB).
- ↑ a b c d e f g ARTE documentation: Fukushima - The truth behind the super-GAU The statements of the NRC are mostly reproduced, commented and dubbed in German by Arnold Gundersen.
- ↑ Earthquake: Japan continues to worry: reactor ruin shines, earth shakes . ( Memento of 31 March 2011 Webcite ) In: zeit.de . Zeit Online, March 19, 2011, accessed March 31, 2011.
- ↑ Michael Winter: New Fukushima fear: Spent fuel at No. 4 might restart chain reaction ( Memento from March 31, 2011 on WebCite ). In: content.usatoday.com . USA TODAY, March 15, 2011, accessed March 31, 2011.
- ↑ Fire in reactor 4 apparently extinguished - two workers missing . ( Memento from April 2, 2011 on WebCite ) derStandard.at, March 16, 2011.
- ↑ Live ticker on the catastrophe in Japan . ( Memento from May 2, 2011 on WebCite ) stern.de: “New access to the reactor is being built”.
- ↑ Press Release (Mar 16,2011) Fire occurrence at Fukushima Daiichi Nuclear Power Station Unit 4 (2nd Release) ( Memento from April 12, 2011 on WebCite ) (English). Tepco, March 16, 2011.
- ↑ SDF trucks join choppers in dousing crisis hit Fukushima reactor ( Memento from April 12, 2011 on WebCite ). Kyodo News, March 17, 2011, accessed March 17, 2011.
- ↑ a b USA doubts Japan's rescue strategy . ( Memento from May 2, 2011 on WebCite ) Spiegel Online, March 17, 2011.
- ↑ Japan quake live blog ( Memento from May 17, 2011 on WebCite ) (English). CNN, March 16, 2011.
- ↑ JU.S. nuclear officials suspect Japanese plant has a dire breach ( Memento from May 15, 2011 on WebCite ). Los Angeles Times, March 18, 2011.
- ↑ Japan Races to Restart Reactors' Cooling System ( Memento from May 15, 2011 on WebCite ) (English). New York Times, March 18, 2011.
- ↑ Spent fuel pool never dried up at Fukushima plant: US regulator ( Memento June 16, 2011 on WebCite ). Kyodo News, June 15, 2011, accessed June 16, 2011.
- ^ David McNeill: 'I am one of the Fukushima fifty': One of the men who risked their lives to prevent a catastrophe shares his story. In: The Independent . March 2, 2013, accessed March 7, 2013 .
- ↑ National Academy of Sciences report: Fukushima Daiichi nuclear accident - Lessons learned for spent fuel storage Chapter 5, page 45
- ↑ Fukushima nuclear power plant: control room in reactor 3 has light again . ( Memento from April 12, 2011 on WebCite ) Hamburger Abendblatt, March 22, 2011.
- ↑ TEPCO confirms damage to part of No. 4 units spent nuke fuel . ( Memento of April 13, 2011 on WebCite ) Kyodo News, April 13, 2011, accessed April 13, 2011.
- ↑ Earthquake Report - JAIF, No. 52: 20:00, April 14 ( Memento from April 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 14, 2011 (PDF; 119 kB).
- ↑ Earthquake Report - JAIF, No. 63: 20:00, April 25 ( Memento from April 25, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 25, 2011 (PDF; 81 kB).
- ↑ Plant Status of Fukushima Daiichi Nuclear Power Station (as of 10:00 am, May 18) ( Memento from May 18, 2011 on WebCite ) (English). Tepco, May 17, 2011.
- ↑ Seismic Damage Information (the 140th Release) ( Memento from May 18, 2011 on WebCite ) (English, pdf). NISA, May 16, 2011.
- ↑ Earthquake Report - JAIF, No. 160 ( Memento from August 1, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 31, 2011 (PDF; 88 kB).
- ↑ Liveticker: Nuclear power plant operators want to prevent new explosions . ( Memento from May 8, 2011 on WebCite ) In: stern.de . March 15, 2011
- ↑ プ ラ ン ト 関 連 パ ラ メ ー タ (2011-03-16: 14: 00) ( Memento from April 16, 2011 on WebCite ) (Japanese, pdf). Ministry of Economy, Trade and Industry, March 16, 2011, accessed April 16, 2011.
- ↑ プ ラ ン ト 関 連 パ ラ メ ー タ (2011-03-18: 14: 00) ( Memento from April 16, 2011 on WebCite ) (Japanese, pdf). Ministry of Economy, Trade and Industry, March 18, 2011, accessed March 25, 2011.
- ^ Fukushima Nuclear Accident Update Log ( April 12, 2011 memento on WebCite ). IAEA, March 16, 2011.
- ↑ Seismic Damage Information (the 33rd Release) (As of 13:30 March 19th, 2011) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 19, 2011.
- ↑ Seismic Damage Information (the 37th Release) (As of 22:30 March 20th, 2011) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 20, 2011.
- ↑ a b Seismic Damage Information (the 63rd Release) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 30, 2011.
- ↑ Status of nuclear power plants in Fukushima as of 16:00 March 22 ( Memento from April 12, 2011 on WebCite ) (English, pdf). JAIF, March 22, 2011 (PDF; 131 kB).
- ↑ プ ラ ン ト 関 連 パ ラ メ ー タ (2011-03-22: 17: 00) ( Memento from April 16, 2011 on WebCite ) (Japanese, pdf). Ministry of Economy, Trade and Industry, March 22, 2011, accessed April 16, 2011.
- ↑ Plan of blocks 5 and 6 ( Memento of April 4, 2011 on WebCite ) (English, pdf). Tepco (PDF; 33 kB).
- ↑ Earthquake Report - JAIF, No. 228 ( Memento of December 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, October 8, 2011 (PDF; 165 kB).
- ↑ Usage of the accumulated water in Unit 5 and 6 after the treatment ( Memento from December 14, 2011 on WebCite ) (English). Tepco, October 7, 2011.
- ↑ Seismic Damage Information (the 41th Release (corrected)) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 22, 2011.
- ↑ Seismic Damage Information (the 34th Release) (As of 20:30 March 19th, 2011) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 19, 2011.
- ↑ Seismic Damage Information (the 53rd Release) (As of 08:00 March 26th, 2011) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 26, 2011.
- ^ Seismic Damage Information (the 49th Release) ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 24, 2011.
- ↑ Seismic Damage Information (the 76th Release) ( Memento from April 16, 2011 on WebCite ) (English, pdf). NISA, April 6, 2011.
- ^ Seismic Damage Information (the 84th Release) ( Memento of April 16, 2011 on WebCite ) (English, pdf). NISA, April 10, 2011.
- ^ John E. Ten Hoeve, Mark Z. Jacobson: Worldwide health effects of the Fukushima Daiichi nuclear accident . In: Energy & Environmental Science . tape 5 , 2012, p. 8743-8757 , doi : 10.1039 / C2EE22019A .
- ↑ Nikolaos Evangeliou, Yves Balkanski, Anne Cozic, Anders Pape Møller: How “lucky” we are that the Fukushima disaster occurred in early spring: Predictions on the contamination levels from various fission products released from the accident and updates on the risk assessment for solid and thyroid cancers . In: Science of The Total Environment . tape 500-501 , 2014, pp. 155–172 , doi : 10.1016 / j.scitotenv.2014.08.102 .
- ↑ UNSCEAR: UNSCEAR 2013 Report. Volume I REPORT TO THE GENERAL ASSEMBLY SCIENTIFIC ANNEX A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami
- ↑ UNSCEAR: Developments since the 2013 UNSCEAR Report on the levels and effects of radiation exposure due to the nuclear accident following the great east-Japan earthquake and tsunami . White Paper, 2015.
- ^ A b WHO: Health Risk Assessment from the nuclear accident after the 2011 Great East Japan Earthquake and Tsunami based on a preliminary dose estimation
- ↑ Hasegawa et al .: From Hiroshima and Nagasaki to Fukushima 2. Health effects of radiation and other health problems in the aftermath of nuclear accidents, with an emphasis on Fukushima . In: The Lancet . tape 386 , no. 9992 , 2015, p. 479-488 , doi : 10.1016 / S0140-6736 (15) 61106-0 .
- ↑ Aftermath of nuclear disaster - Fukushima workers irradiated much worse. In: Focus , October 12, 2013. Retrieved October 13, 2013.
- ↑ At least 20 Tepco employees exposed to radiation; Injured at the Fukushima I nuclear power plant . ( Memento from April 2, 2011 on WebCite ) In: tagesschau.de . ARD, March 16, 2011, accessed April 2, 2011.
- ↑ a b Radiation exposure levels near limit for 2 Fukushima nuke workers ( Memento from May 1, 2011 on WebCite ) (English). The Mainichi Daily News, May 1, 2011, accessed May 1, 2011.
- ↑ TEPCO workers not warned of radiation risk ( Memento of May 14, 2011 on WebCite ) (English). Yomiuri Shimbun, March 27, 2011.
- ↑ 2 of 3 radiation-exposed workers suffer internal exposure ( Memento of May 17, 2011 on WebCite ) (English). Kyodo News, March 25, 2011, accessed May 15, 2011.
- ↑ a b c d e f Seismic Damage Information (the 127th Release) ( Memento from May 14, 2011 on WebCite ) (English, pdf). NISA, May 6, 2011. Injured employees on pp. 52–55
- ↑ a b Enhancing controls of internal exposures at Fukushima Daiichi Nuclear Power Station ( Memento of December 11, 2011 on WebCite ) (English). Tepco, September 30, 2011, accessed December 11, 2011.
- ↑ a b Radiation monitors not given to each worker ( Memento from April 11, 2011 on WebCite ) (English). In: nhk.or.jp . NKH World, March 31, 2011, accessed May 7, 2011.
- ↑ Exposure of Tepco pair exceeds limit ( Memento from May 30, 2011 on WebCite ) (English). The Japan Times, May 30, 2011.
- ↑ Status of Evaluation work of TEPCO employees' Exposure Dose at Fukushima Daiichi Nuclear Power Station (Continued Releases) ( Memento June 10, 2011 on WebCite ). Tepco, June 10, 2011.
- ↑ N-worker's mask left no room for glasses ( Memento from June 20, 2011 on WebCite ) (English). Yomiuri Shimbun, June 19, 2011.
- ↑ Enhancing controls of internal exposures at Fukushima Daiichi Nuclear Power Station ( Memento from December 15, 2011 on WebCite ) (English). Tepco, November 30, 2011, accessed December 15, 2011.
- ↑ Bad Health of a Worker of a Sub-Contractor in Fukushima Daiichi Nuclear Power Station (Continued report) ( Memento from May 17, 2011 on WebCite ) (English, pdf). Tepco, May 15, 2011.
- ↑ Heart attack likely killed N-worker ( Memento from May 17, 2011 on WebCite ) (English). Yomiuri Shimbun, May 16, 2011.
- ↑ Families want answers after 45 people die following evacuation from Fukushima hospital ( Memento from December 20, 2011 on WebCite ) (English). The Mainichi Daily News, April 26, 2011, accessed December 20, 2011.
- ^ TV documentary "Lives Slipped Away" ( Memento from April 10, 2014 in the Internet Archive ), NHK.
- ↑ 西 堀 岳 路: 福島 の 野菜 農家 が 自殺 摂 取 制 限 指示 に 「も う だ め だ」 ( Memento from April 19, 2011 on WebCite ) (Japanese). asahi.com, March 29, 2011, accessed April 19, 2011.
- ^ Man, 102, 'kills self over nuclear evacuation plan' ( Memento December 20, 2011 on WebCite ). The Straits Times, April 14, 2011, accessed December 20, 2011.
- ↑ Peter Caracappa: Fukushima Accident: Radioactive Releases and Potential Dose Consequences ( Memento from December 20, 2011 on WebCite ) (English, pdf). June 28, 2011, accessed December 20, 2011.
- ^ Frank von Hippel: The radiological and psychological consequences of the Fukushima Daiichi accident ( Memento from December 20, 2011 on WebCite ) (English). In: Bulletin of the Atomic Scientists . October 2011, accessed December 20, 2011.
- ↑ Dennis Normille: Fukushima Revives The Low-Dose Debate ( Memento of 20 December 2011 Webcite ) (English). In: Science . May 20, 2011.
- ↑ 51 US soldiers fall ill with cancer after their Fukushima mission. In: Focus , January 7, 2014. Retrieved January 7, 2014.
- ↑ US soldiers seriously ill after the Fukushima mission. In: Die Welt , January 7, 2014. Retrieved January 7, 2014.
- ^ Navy sailors have radiation sickness after Japan rescue. In: New York Post , December 22, 2013. Retrieved January 7, 2014.
- ↑ James Conca: Court Rejects US Sailors' Lawsuit Over Fukushima Radiation Exposure. Retrieved on August 16, 2020 .
- ↑ Asahi Shimbun: Fukushima finds new thyroid cancers ( Memento from February 27, 2016 in the Internet Archive )
- ↑ Federal Office of Public Health (Switzerland): Radioactivity and Radiation Protection , 1999
- ^ S. Yamashita, S. Suzuki, S. Suzuki, H. Shimura, V. Saenko: Lessons from Fukushima: Latest Findings of Thyroid Cancer After the Fukushima Nuclear Power Plant Accident. In: Thyroid: official journal of the American Thyroid Association. Volume 28, number 1, 01 2018, pp. 11-22, doi: 10.1089 / thy.2017.0283 , PMID 28954584 , PMC 5770131 (free full text).
- ↑ Fukushima Nuclear Accident Update (March 19, 2011 12:00 UTC) - Corrected ( Memento from April 12, 2011 on WebCite ). IAEA, March 19, 2011.
- ↑ Japan's government warns against contaminated drinking water . ( Memento from April 12, 2011 on WebCite ) Spiegel Online, March 20, 2011.
- ^ Fukushima Nuclear Accident Update Log; Updates of 25 March 2011 ( Memento from April 12, 2011 on WebCite ). IAEA, March 25, 2011.
- ↑ Implementing Regulation (EU) No. 297/2011 of the Commission , accessed on April 5, 2011 .
- ↑ Regulation (EEC) No. 944/89 of the Commission of April 12, 1989 laying down maximum levels of radioactivity in foods of minor importance in the event of a nuclear accident or other radiological emergency .
- ↑ Regulation (EEC) No. 2218/89 of the Council of July 18, 1989 amending Regulation (Euratom) No. 3954/87 laying down maximum levels of radioactivity in food and feed in the event of a nuclear accident or other radiological emergency .
- ↑ EU adopts stricter limits for Japanese food . ( Memento of April 8, 2011 on WebCite ) Financial Times Deutschland, April 8, 2011, accessed May 7, 2011.
- ^ A correction of "The status of water analysis in the trench of Fukushima Daiichi Nuclear Power Station" ( Memento of April 12, 2011 on WebCite ) (English). Tepco, March 31, 2011.
- ↑ The result of the nuclide analysis of seawater around 15 km off shore of Fukushima Daiichi Nuclear Power Station ( Memento from April 12, 2011 on WebCite ) (English, pdf). Tepco, April 7, 2011 (PDF; 12 kB).
- ↑ Earthquake Report - JAIF, No. 44: 20:00, April 6 . ( Memento from April 9, 2011 on WebCite ) JAIF / NHK, April 6, 2011 (PDF; 140 kB): “Ibaraki fishermen suspend fishing activities”.
- ↑ Seismic Damage Information (the 131st Release) ( Memento from May 29, 2011 on WebCite ) (English). NISA, May 9, 2011.
- ↑ Earthquake Report - JAIF, No. 148: 20:00, July 20 . ( Memento from August 15, 2011 on WebCite ) JAIF / NHK, July 20, 2011 (PDF; 88 kB).
- ↑ Earthquake Report - JAIF, No. 150 ( Memento from July 30, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 22, 2011 (PDF; 90 kB).
- ↑ Earthquake Report - JAIF, No. 157 ( Memento of July 30, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 29, 2011 (PDF; 141 kB).
- ↑ Local gov'ts worried by N-ash ( Memento from August 14, 2011 on WebCite ) (English). Yomiuri Shimbun, August 12, 2011.
- ↑ Radioactively contaminated groundwater in Fukushima faz.net, June 19, 2013
- ↑ spiegel.de July 9, 2013: Radioactive pollution of the groundwater increases dramatically
- ↑ Fukushima. Abe is troubled by Tepco's lies. In: Frankfurter Allgemeine Zeitung , August 7, 2013. Accessed August 7, 2013.
- ↑ Concern for contaminated water. ( Memento from August 9, 2013 in the Internet Archive ) In: Tagesschau.de , August 7, 2013. Retrieved on August 7, 2013.
- ↑ 300 tons of radioactive water leaked. In: Süddeutsche Zeitung , August 20, 2013. Accessed August 20, 2013.
- ↑ Japan declares radioactive leak a "serious incident". In: Frankfurter Allgemeine Zeitung , August 21, 2013. Accessed August 21, 2013.
- ↑ Japan raises warning level in Fukushima. In: Süddeutsche Zeitung , August 21, 2013. Accessed August 21, 2013.
- ↑ Radioactivity: Extreme radiation measured at Fukushima water tank. In: Spiegel Online , September 1, 2013. Accessed September 1, 2013.
- ↑ Experts baffled as robots sent to clean up Fukushima nuclear site keep dying
- ^ INES - The International Nuclear and Radiological Event Scale. (PDF; 193 kB) International Atomic Energy Agency , August 1, 2008, accessed on February 12, 2020 (English).
- ↑ Explosion in Fukushima 1 classified as an "accident" . ( Memento from April 12, 2011 on WebCite ) NZZ Online, March 12, 2011.
- ↑ Japan: Status report from March 19, 2011, 11:00 a.m. (CET) . ( Memento from April 12, 2011 on WebCite ) Society for Reactor Safety , March 19, 2011.
- ↑ INES Ratings on the Events in Fukushima Dai-ichi NPS and Fukushima Dai-ni NPS by the Tohoku Regional Pacific Ocean Offshore Earthquake ( Memento from April 12, 2011 on WebCite ) (English, pdf). NISA, March 19, 2011.
- ↑ ISIS Statement on Events at Fukushima Daiichi Nuclear Site in Japan ( Memento from April 12, 2011 on WebCite ) (English). Institute for Science and International Security, March 15, 2011, accessed March 15, 2011.
- ↑ IRSN publishes assessment of radioactivity released by the Fukushima Daiichi Nuclear Power Plant (Fukushima I) through March 22, 2011 ( Memento from April 2, 2011 on WebCite ) (English, pdf). Institut de Radioprotection et de sûreté nucléaire, March 22, 2011 (PDF; 33 kB).
- ^ Accident in the Japanese nuclear power plant in Fukushima (Update: March 23, 2011 11:00 am) . ( Memento from April 12, 2011 on WebCite ) Central Institute for Meteorology and Geodynamics (ZAMG), March 23, 2011.
- ↑ Fukushima - classification on the INES scale ( memento of April 2, 2011 on WebCite ) (pdf). Greenpeace, March 23, 2011 (PDF; 116 kB).
- ↑ a b Fukushima Nuclear Accident Update Log ( Memento from April 15, 2011 on WebCite ) (English). IAEA, April 12, 2011.
- ↑ a b INES - The International Nuclear and Radiological Event Scale: User's Manual 2008 Edition ( Memento from April 12, 2011 on WebCite ) (English - PDF; 2.5 MB). IAEA, May 2009, accessed March 23, 2011.
- ↑ Seismic Damage Information (24th Release) as of 11:00 March 15th, 2011 ( Memento from April 12th 2011 on WebCite ) (English, pdf). NISA, March 15, 2011.
- ↑ Evacuation advised for 80,000 near nuclear plants ( memento April 9, 2011 on WebCite ). In: NHK World News . NHK, March 13, 2011
- ↑ a b Life in Limbo for Japanese Near Nuclear Plant ( Memento from May 2, 2011 on WebCite ) (English). New York Times, May 1, 2011.
- ↑ Original ( Memento from April 11, 2011 on WebCite ) (English). Kyodo News, March 25, 2011 to April 11, 2011.
- ↑ a b Japanese complain about a lack of information. ( Memento from May 23, 2011 on WebCite ) Der Standard, March 26, 2011.
- ↑ Original ( Memento from April 11, 2011 on WebCite ) (English). In: NHK World . NHK, March 26, 2011 to April 11, 2011.
- ↑ 福島 ・ 双 葉 町 、 避難 先 を 埼 玉 ・ 加 須 市 に 移動 . In: 日 テ レ NEWS24. Nippon Terebi Hōsōmō , March 31, 2011, archived from the original on August 2, 2011 ; Retrieved August 2, 2011 (Japanese).
- ↑ Original ( Memento from May 1, 2011 on WebCite ) (Japanese). In: mainichi.jp . Mainichi Shimbun- sha, April 10, 2011 on May 1, 2011, accessed on May 2, 2011. Overview of reported dead, missing and evacuated persons.
- ↑ Seismic Damage Information (the 61st Release) ( Memento April 11, 2011 on WebCite ) (English, pdf). In: nisa.meti.go.jp . NISA, March 29, 2011.
- ↑ Atomic experts consider the exclusion zone too small . sueddeutsche.de, March 17, 2011, accessed on April 12, 2011.
- ↑ Greenpeace radiation experts present findings, announce further Fukushima contamination work ( Memento from April 11, 2011 on WebCite ). Greenpeace, March 29, 2011.
- ^ Greenpeace calls for the evacuation of Iitate . ( Memento from April 11, 2011 on WebCite ) Der Tagesspiegel, March 30, 2011.
- ^ Fukushima Nuclear Accident Update Log ( Memento of May 29, 2011 on WebCite ). IAEA, March 30, 2011.
- ↑ a b Gov't reviewing radiation exposure level for evacuation ( Memento from April 11, 2011 on WebCite ) (de). Kyodo News, April 6, 2011, accessed April 6, 2011.
- ^ Radiation Exposure in Daily Life (Japan) ( Memento April 6, 2011 on WebCite ). MEXT, March 15, 2011.
- ↑ Japan expands evacuation areas around crippled nuclear plant ( Memento from April 12, 2011 on WebCite ) (English). Kyodo News, April 11, 2011, accessed April 12, 2011.
- ↑ a b Earthquake Report - JAIF, No. 60: 20:00, April 22 ( Memento from April 22, 2011 on WebCite ) (English). JAIF / NHK, April 22, 2011 (PDF; 81 kB).
- ↑ Haphazardly in the crisis . ( Memento from April 17, 2011 on WebCite ) Der Tagesspiegel, April 17, 2011.
- ↑ Earthquake Report - JAIF, No. 72 ( Memento from May 5, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 5, 2011 (PDF; 255 kB).
- ↑ Japan slaps entry ban around plant ( Memento from April 22, 2011 on WebCite ) (English, pdf). Global Times, China, April 22, 2011.
- ↑ Seismic Damage Information (the 108th Release), Extract ( Memento from April 23, 2011 on WebCite ) (English, pdf). NISA, April 22, 2011.
- ↑ Evacuation urged for radioactive hot spots ( Memento from June 16, 2011 on WebCite ) (English). Japan Times, June 16, 2011.
- ↑ Earthquake Report - JAIF, No. 129 ( Memento of July 3, 2011 on WebCite ) (English). JAIF / NHK, July 1, 2011 (PDF; 122 kB).
- ↑ Seismic Damage Information (the 219th Release), Extract ( Memento from August 14, 2011 on WebCite ) (English, pdf). NISA, August 3, 2011.
- ^ Residents frustrated by 'hot spot' designation ( Memento from August 17, 2011 on WebCite ). Yomiuri Shimbun, August 17, 2011, accessed August 17, 2011.
- ↑ Earthquake Report - JAIF, No. 220 ( Memento of December 11, 2011 on WebCite ) (English). JAIF / NHK, September 30, 2011 (PDF; 56 kB).
- ↑ Earthquake Report - JAIF, No. 203 ( Memento of December 11, 2011 on WebCite ) (English). JAIF / NHK, September 27, 2011 (PDF; 78 kB).
- ↑ Earthquake Report - JAIF, No. 203 ( Memento of December 11, 2011 on WebCite ) (English). JAIF / NHK, September 13, 2011 (PDF; 67 kB).
- ↑ Residents of a city near Fukushima are allowed to return. In: Deutsche Welle. September 5, 2015, accessed September 8, 2015 .
- ↑ 2011-03-12 . ( Memento from April 29, 2011 on WebCite ) In: tagesschau.de
- ↑ Partial travel warning for Northeast Japan . ( Memento from April 12, 2011 on WebCite ) Wiener Zeitung, March 12, 2011.
- ^ Directory of the Austrian representation authorities ( Memento from April 12, 2011 on WebCite ) (pdf). Federal Ministry for European and International Affairs (PDF; 523 kB): “As of March 16, 2011, the embassy will temporarily transfer its operational activities to the Honorary Consulate General Osaka. (P. 81) ".
- ↑ German embassy relocated to Osaka . ( Memento from April 30, 2011 on WebCite ) In: reiseinfoweb.de . March 17, 2011.
- ↑ a b US citizens should leave Japan . ( Memento from April 11, 2011 on WebCite ) In: stern.de . March 17, 2011.
- ↑ Travel Advice, Japan ( Memento from May 17, 2011 on WebCite ) (English). Australian Government, Department of Foreign Affairs and Trade, May 15, 2011.
- ↑ S. Koreans in Japan urged to stay 80 km outside crippled reactors ( Memento from May 17, 2011 on WebCite ) (English). Kyodo News, March 17, 2011 on May 17, 2011, accessed May 15, 2011.
- ↑ No nuclear panic in Asia and the Pacific region . ( Memento from April 11, 2011 on WebCite ) In: focus.de . March 16, 2011.
- ↑ New power line to Fukushima almost finished . ( Memento from April 11, 2011 on WebCite ) Spiegel Online, March 16, 2011.
- ↑ a b Debate The Real Danger , by Robert Peter Gale, April 4, 2011, Der Spiegel ( Archive ( Memento from April 11, 2011 on WebCite ))
- ↑ Live ticker on the disaster in Japan . ( Memento from April 12, 2011 on WebCite ) Financial Times Deutschland, April 12, 2011, accessed April 12, 2011.
- ↑ US lets embassy staff families to return to Japan after evacuation ( Memento from April 15, 2011 on WebCite ). Kyodo News, April 15, 2011, accessed April 15, 2011.
- ↑ German Embassy in Japan is again working from Tokyo . ( Memento from April 30, 2011 on WebCite ) Stern, April 29, 2011.
- ↑ Robert Sham: Re: RJSS / SDJ (Sendai Airport - Japan - 11 / Mar / 2011) ( Memento from April 15, 2011 on WebCite ) (English). IVAO Community Forum - France, March 12, 2011: "B1048 / 11… All ACFT Are Requested to Avoid Flying the FLW Airspace Within a Radius of 20 km FM 372529N1410158E The Tokyo Electric Power Co., Inc. Fukushima No. 1 ”.
- ↑ Japan Crisis including NOTAM (Update) ( Memento from April 10, 2011 on WebCite ) (English). National Business Aviation Association, March 25, 2011.
- ↑ Lufthansa checks machines for radiation when they return from Japan . ( Memento from April 10, 2011 on WebCite ) stern.de, March 14, 2011.
- ↑ Lufthansa no longer flies to Tokyo . ( Memento from April 10, 2011 on WebCite ) Spiegel Online , March 15, 2011.
- ↑ Current travel information ( Memento from March 26, 2011 on WebCite ) (English). Lufthansa , March 23, 2011, accessed on March 26, 2011.
- ↑ AUA is currently flying on to Tokyo . ( Memento from April 3, 2011 on WebCite ) Österreichischer Rundfunk Vienna, March 17, 2011.
- ↑ Martin Metzenbauer: Euro Airlines fly on to Tokyo . ( Memento from April 10, 2011 on WebCite ) Austrian Aviation Net, March 16, 2011.
- ↑ EU orders compulsory controls for food from Japan. Today.de, March 24, 2011. Archived print version. ( Memento from April 12, 2011 on WebCite )
- ↑ 10,000-fold increase in radiation in another reactor . ( Memento from April 11, 2011 on WebCite ) Die Welt, March 25, 2011.
- ↑ South Korea does not consider it necessary to stop imports of products from Fukushima . ( Memento from April 11, 2011 on WebCite ) KBS World, March 24, 2011.
- ^ Chronicle of the catastrophe . ( Memento from April 14, 2011 on WebCite ) Financial Times Deutschland, April 14, 2011, accessed April 14, 2011.
- ↑ a b Chronicle of the catastrophe in Japan . ( Memento from April 12, 2011 on WebCite ) Financial Times Deutschland, April 6, 2011, accessed April 7, 2011.
- ↑ City starts decontamination work ( Memento of August 14, 2011 on WebCite ) (English). Yomiuri Shimbun, August 12, 2011.
- ↑ a b Earthquake Report - JAIF, No. 281 ( Memento of December 14, 2011 on WebCite ) (English, pdf). JAIF / NHK, December 4, 2011 (PDF; 211 kB).
- ^ Representatives of the ruling party: Return to Fukushima impossible. tagesschau.de, November 3, 2013, archived from the original on November 4, 2013 ; Retrieved November 3, 2013 .
- ↑ a b c d e f g h i Fukushima operators: a squad of failures . ( Memento from April 9, 2011 on WebCite ) In: Die Zeit No. 14/2011 . Zeitverlag Gerd Bucerius, March 31, 2011.
- ↑ a b c d e U.S. 'frustrated' over Japan's lack of N-info ( Memento from May 22, 2011 on WebCite ). Yomiuri Shimbun, April 12, 2011.
- ↑ Earthquake Report - JAIF, No. 116 ( Memento from June 18, 2011 on WebCite ) (English, pdf). JAIF / NHK, June 18, 2011 (PDF; 334 kB): "IAEA report on Fukushima nuclear accident"
- ↑ Executive summary ( Memento of July 6, 2012 in the Internet Archive )
- ↑ Angela Köhler: The Fukushima disaster could have been prevented: badische-zeitung.de, Nachrichten, Ausland, July 6, 2012 (July 13, 2012)
- ↑ Fukushima disaster: Tokyo hides truth as children die, become ill from radiation - ex-mayor Russia Today video from April 21, 2014
- ↑ a b One crisis after another harried TEPCO's response ( Memento from May 22, 2011 on WebCite ) (English). Yomiuri Shimbun, April 14, 2011: "They were becoming frustrated by what they saw as constant changes to explanations about what was happening at the power station."
- ↑ a b c d e f Distrust grows among N-crisis players ( Memento from May 22, 2011 on WebCite ) (English). Yomiuri Shimbun, April 2, 2011.
- ↑ Nuclear Crisis: How It Happened / 'Nuclear power village' a cozy, closed community ( Memento from June 18, 2011 on WebCite ) (English). Yomiuri Shimbun, June 16, 2011.
- ↑ a b Incompetence and deception . ( Memento from April 9, 2011 on WebCite ) Spiegel Online, March 15, 2011.
- ↑ Welt online, March 9, 2012: A fit of anger prevented an atomic horror scenario , inserted March 27, 2012
- ↑ Tepco or two decades full of breakdowns . ( Memento from April 9, 2011 on WebCite ) Der Standard, March 16, 2011.
- ↑ a b c d Absent TEPCO execs slowed crucial action ( Memento from May 22, 2011 on WebCite ) (English). Yomiuri Shimbun, April 13, 2011.
- ↑ Additional monitoring data at Fukushima Daiichi Nuclear Power Station ( Memento from May 29, 2011 on WebCite ) (English). Tepco, May 28, 2011.
- ↑ a b c d In Japan Reactor Failings, Danger Signs for the US ( Memento from May 22, 2011 on WebCite ), p. 2 ( Memento from May 21, 2011 on WebCite ) (English). New York Times, May 17, 2011.
- ↑ a b Bid to 'Protect Assets' Slowed Reactor Fight ( Memento from May 22, 2011 on WebCite ) (English). Wall Street Journal, March 21, 2011.
- ↑ Kan denies ordering TEPCO to stop seawater injection at reactor ( Memento from May 23, 2011 on WebCite ) (English). Japan Today, May 23, 2011; accessed May 23, 2011.
- ↑ No order to halt seawater, Kan says ( Memento from May 26, 2011 on WebCite ) (English). Yomiuri Shimbun, May 24, 2011.
- ↑ a b Earthquake and tsunami in Japan, Areva aid according to company website ( Memento from April 10, 2011 on WebCite ) (English)
- ↑ Reuters Anne Lauvergeon et des experts d'Areva se rendent au Japon ( Memento of April 10, 2011 on WebCite ) (French). Reuters, March 29, 2011.
- ↑ Japan nuclear commission fails to send experts to Fukushima ( Memento of April 16, 2011 on WebCite ) (English). Kyodo News, April 16, 2011, accessed April 16, 2011.
- ↑ Tokyo Electric comes under fire for releasing wrong nuclear data ( Memento from April 9, 2011 on WebCite ) (English). Kyodo News, March 28, 2011, accessed March 28, 2011.
- ^ Fears of radioactive seawater grow near nuke plant despite efforts ( Memento from April 9, 2011 on WebCite ) (English, pdf). Kyodo News, March 27, 2011, accessed March 26, 2011: "chief Cabinet secretary also urged TEPCO to disclose information in a more appropriate and timely manner".
- ↑ a b Improvement plan for the exact nuclide analysis at the site of Fukushima Daiichi Nuclear Power Station under instruction of NISA ( Memento from April 21, 2011 on WebCite ) (English). Tepco, April 4, 2011.
- ↑ a b Radiation Errors Erode Confidence in Power Company ( Memento from May 23, 2011 on WebCite ) (English). New York Times, April 5, 2011.
- ↑ UN criticizes nuclear chaos of the Japanese government. ( Memento from May 23, 2011 on WebCite ) stern.de, March 31, 2011.
- ↑ Werner Eckert: Who sets the limit values for radiation? . ( Memento from April 1, 2011 on WebCite ) In: blog.tagesschau.de . ARD, March 24, 2011, accessed April 1, 2011.
- ↑ TEPCO contractors reject higher radiation dose limit for workers ( Memento of April 11, 2011 on WebCite ). Kyodo News, April 9, 2011, accessed April 9, 2011.
- ↑ Crack in the floor of reactor 2 - The events of Saturday . ( Memento from April 11, 2011 on WebCite ) Financial Times Deutschland, April 2, 2011, accessed April 2, 2011.
- ↑ Improvement of the living environment of the workers at Fukushima Daiichi and Daini Nuclear Power Stations ( Memento from May 5, 2011 on WebCite ) (English). Tepco, May 4, 2011.
- ^ J-Village: Base Camp For The Fukushima Daiichi Clean-up ( Memento from May 15, 2011 in the Internet Archive ) (English). Japan Probe, April 17, 2011, accessed May 2, 2011.
- ↑ a b Food safety inspections flawed / Critics say system inconsistent, inequitably applied, lacks oversight ( Memento from May 23, 2011 on WebCite ) (English). Yomiuri Shimbun, March 29, 2011.
- ↑ Japan changes scope of restrictions on farm products ( Memento of April 20, 2011 on WebCite ) (English). Kyodo News, April 4, 2011, accessed April 4, 2011.
- ^ Nuclear Education and Research Initiative, Program Members . ( Memento April 29, 2011 on WebCite ) The University of Tokyo.
- ↑ a b c Japan's nuclear adviser resigns in tears . ( Memento from May 1, 2011 on WebCite ) Zeit Online, April 30, 2011.
- ↑ More robots soon to be deployed in Fukushima / Japan's head of government's nuclear advisor resigns . ( Memento from May 3, 2011 on WebCite ) Hamburger Abendblatt, April 29, 2011.
- ^ Cabinet nuclear advisor resigns in protest over government response to plant crisis . ( Memento of May 3, 2011 on WebCite ) The Mainichi Daily News, April 30, 2011, accessed May 2, 2011.
- ↑ a b Earthquake Report - JAIF, No. 42: 20:00, April 4 ( memento of April 23, 2011 on WebCite ) (English, pdf). JAIF / NHK, April 4, 2011 (PDF; 145 kB).
- ↑ a b Earthquake Report - JAIF, No. 70 ( Memento from May 3, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 3, 2011 (PDF; 193 kB).
- ^ A b Government Adviser Quits Post to Protest Japan's Policy on Radiation Exposure for Fukushima Schools . ( Memento dated May 1, 2011 on WebCite ) Science, April 29, 2011.
- ↑ 福島 県 内 の 学校 等 の 校 舎 ・ 校 庭 等 の 利用 判断 に お け る 暫定 的 考 え 方 に つ い て (for example: First considerations on regulations for the use of school land in Fukushima Prefecture) ( Memento from May 3, 2011 in WebCite ) (Japanese). MEXT , April 19, 2011.
- ↑ a b c Life in Limbo for Japanese Near Nuclear Plant ( Memento from May 3, 2011 on WebCite ) (english). New York Times, May 1, 2011: "The Education Ministry's guidelines take into account the child's exposure to radiation during the entire day, both at home and school".
- ↑ a b petition . ( Memento of May 3, 2011 on WebCite ) International forum on globalization.
- ↑ Japan sets high radiation limits for children . ( Memento from May 3, 2011 on WebCite ) Spiegel Online, April 21, 2011.
- ↑ a b Japan’s Prime Minister Defends Handling of Crisis ( Memento from May 3, 2011 on WebCite ) (English). New York Times, May 1, 2011.
- ↑ Government gives 33 billion euros for reconstruction . ( Memento from May 3, 2011 on WebCite ) Spiegel Online, April 22, 2011.
- ↑ a b Rating agency doubts Japan's creditworthiness . ( Memento from May 3, 2011 on WebCite ) Spiegel Online, April 27, 2011.
- ↑ Readings of dust sampling (1/2) ( Memento from May 23, 2011 in the Internet Archive ) (English, pdf). MEXT, May 1, 2011] on May 3, 2011, accessed May 3, 2011.
- ↑ 56% want gov't to hike crisis funds / 59% unhappy with efforts since quake ( Memento from May 20, 2011 on WebCite ). Yomiuri Shimbun, May 17, 2011.
- ↑ Earthquake Report - JAIF, No. 91 ( Memento of May 27, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 24, 2011 (PDF; 101 kB).
- ↑ Earthquake Report - JAIF, No. 93 ( Memento of May 27, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 27, 2011 (PDF; 165 kB).
- ↑ Forgotten on the edge of the contaminated no man's land . In: Die Zeit , March 11, 2015. Retrieved March 13, 2015.
- ^ The Associated Press: Fukushima Update. The New York Times, August 12, 2015, accessed August 22, 2015 .
- ↑ The Fukushima Effect , NZZ online, March 27, 2011
- ↑ Fukushima effect also from Swiss , Basler Zeitung of April 14, 2011, accessed on May 29, 2011.
- ↑ Nuclear crisis forces firms to shift production from quake-hit region - English ( Memento from April 12, 2011 on WebCite ) (English). In: asahi.com . Asahi Shimbun , March 20, 2011.
- ↑ Real estate fund closes due to the Japanese crisis . ( Memento from April 12, 2011 on WebCite ) Handelsblatt, March 17, 2011.
- ↑ Earthquake Report - JAIF, No. 48: 18:00, April 10 ( Memento from April 10, 2011 on WebCite ) (English). JAIF / NHK, April 10, 2011 (PDF; 80 kB).
- ↑ Earthquake Report - JAIF, No. 85 ( Memento from May 20, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 18, 2011 (PDF; 90 kB).
- ↑ Fear of radiation slows shipping traffic . ( Memento from April 12, 2011 on WebCite ) Spiegel, March 26, 2011.
- ↑ Ticker on the disaster in Japan . ( Memento from April 12, 2011 on WebCite ) Financial Times Deutschland, April 7, 2011, accessed on April 7, 2011: “Due to a massive slump in demand, Japan Airlines (JAL) asked its employees to take unpaid leave in May and June to take."
- ↑ a b Japan reports first trade deficit in 32 years after tsunami. Trade figures reveal collapse in sales to Europe, as cost of oil gas and yen rise. In: The Guardian . January 25, 2012, accessed March 12, 2012 .
- ↑ Status of TEPCO's Facilities and its services after the Tohoku-Chihou-Taiheiyou-Oki Earthquake (as of 4:00 PM) ( Memento from April 24, 2011 on WebCite ) (English). Tepco, April 14, 2011.
- ↑ Naoto Kan: Message from the Prime Minister ( Memento from May 27, 2011 on WebCite ) (English). Kantei, March 13, 2011.
- ↑ Implementation of rolling blackout and request for further energy saving ( Memento of May 10, 2011 on WebCite ). Tepco, March 13, 2011.
- ↑ zeit.de: A people save electricity
- ↑ huffingtonpost.com Setsuden Poised to Replace Nuclear Power in Japan
- ↑ (Comment) Lift of Electricity Consumption Restriction per Article 27 of Electricity Business Act ( Memento of December 11, 2011 on WebCite ), Tepco, September 9, 2011.
- ↑ welt.de: Japan: Last nuclear reactor still in operation shut down (accessed on May 5, 2012).
- ↑ a b Atom: Japan drives atomic reactors up again at focus.de, June 16, 2012 (accessed on June 16, 2012).
- ↑ Matthew Neidell, Shinsuke Uchida, Marcella Veronesi: Be Cautious with the Precautionary Principle: Evidence from Fukushima Daiichi Nuclear Accident. Institute for Labor Economics, October 2019, accessed December 9, 2019 .
- ↑ After shutdown of all nuclear power plants because of Fukushima: Japan puts two nuclear reactors back into operation ( memento from June 19, 2012 in the Internet Archive ) at tagesschau.de, June 16, 2012 (accessed June 16, 2012)
- ↑ Energy policy: Japan powers up the nuclear reactor for the first time since Fukushima at zeit.de, July 1, 2012 (accessed on July 2, 2012).
- ↑ Nuclear catastrophe in Japan: Nuclear power plant operator slouches again with radiation measurements . ( Memento from April 12, 2011 on WebCite ) In: spiegel.de . Spiegel Online , April 1, 2011.
- ↑ Japan: The Runaways . ( Memento from April 12, 2011 on WebCite ) In: faz.net . Frankfurter Allgemeine Zeitung , April 2, 2011: “Flyjin” is the nickname given to the foreigners who have fled, not least the Germans, based on the Japanese word for foreigners, gaijin. It is not the Japanese media that make fun of the "flyjin" or are outraged. It is the foreigners who remained in Tokyo who coined the term. "
- ↑ UN chief stress urgency of reviewing global nuclear safety regime ( Memento of 27 April 2011 Webcite ) (English). Kyodo News, April 26, 2011, accessed April 27, 2011.
- ↑ Kan to review plan to build more nuclear plants from scratch ( Memento from April 10, 2011 on WebCite ). Kyodo News, March 31, 2011
- ↑ Nuke crisis in Fukushima forces utilities to delay restart of reactors ( Memento from April 10, 2011 on WebCite ) (English). Kyodo News, April 3, 2011, accessed April 13, 2011.
- ↑ Kyushu Electric shelves plan to build 3rd nuke reactor in Kagoshima ( Memento from April 12, 2011 on WebCite ) (English). Kyodo News, April 12, 2011, accessed April 12, 2011.
- ↑ Kan looks at separating nuclear safety agency from industry ministry ( Memento of April 10, 2011 on WebCite ). Kyodo News, March 30, 2011, accessed May 7, 2011.
- ↑ As a lone warrior against nuclear power . ( Memento from April 8, 2011 on WebCite ) Spiegel Online, March 31, 2011.
- ↑ A delicate choice between rays and school . ( Memento from April 10, 2011 on WebCite ) Der Standard, April 1, 2011.
- ↑ 17,500 gather for Tokyo rallies against nuclear plants ( Memento April 10, 2011 on WebCite ) (English). Kyodo News, April 10, 2011, accessed April 10, 2011.
- ↑ Japan refrains from expanding nuclear power . ( Memento from May 17, 2011 on WebCite ) Zeit.de, May 10, 2011.
- ↑ Earthquake Report - JAIF, No. 135 ( Memento of July 7, 2011 on WebCite ) (English, pdf). JAIF / NHK, July 7, 2011 (PDF; 132 kB).
- ↑ Earthquake Report - JAIF, No. 165 ( Memento from August 6, 2011 on WebCite ) (English, pdf). JAIF / NHK, August 6, 2011 (PDF; 208 kB).
- ↑ Earthquake Report - JAIF, No. 164 ( Memento from August 6, 2011 on WebCite ) (English, pdf). JAIF / NHK, August 5, 2011 (PDF; 118 kB).
- ^ New N-agency to be free from industry ministry ( Memento of December 13, 2011 on WebCite ) (English). Yomiuri Shimbun, August 14, 2011.
- ↑ New N-safety agency faces difficulties ( Memento from December 13, 2011 on WebCite ) (English). Yomiuri Shimbun, August 18, 2011.
- ↑ 原子 力 規 制 委 、 人事 は 横 滑 り 保安 院 と 安全 委 19 日 廃 止 . In: Asahi Shimbun . September 18, 2012, Retrieved September 22, 2012 (Japanese).
- ↑ Because of the reactor accident in Fukushima: Japan announces nuclear phase-out by 2040 at focus.de, September 14, 2012 (accessed on September 14, 2012).
- ↑ Energy transition: Japan restricts nuclear phase-out again at zeit.de, September 19, 2012 (accessed on September 20, 2012).
- ↑ spiegel.de December 27, 2012: Japan announces construction of new nuclear reactors
-
↑ Two nuclear reactors are allowed to go back online in Japan. In: news.ORF.at. ORF , June 13, 2017, accessed on July 17, 2017 : " In connection with relevant quotes from this ORF News article:
*" In 2015, the first two reactors were reconnected to the grid in southwest Japan. Five are now back in operation across the country. Only a week
ago a reactor at the Takahama nuclear power plant was restarted. ” *“ […] A Japanese court today approved the restart of two nuclear reactors. Reactors 3 and 4 of the Genkai nuclear power plant in southwestern Japan should go back online after the court ruling [...] " " - ↑ Nuclear power plants are being scrutinized in the EU ( Memento from June 16, 2011 on WebCite ). Reuters, May 25, 2011.
- ↑ Energy in Europe Newsletter ( Memento of June 16, 2011 on WebCite ), European Commission, General Directorate for Energy, May 26, 2011.
- ↑ Communication on the comprehensive risk and safety assessments ("stress tests") of nuclear power plants in the European Union and related activities ( Memento of October 21, 2012 in the Internet Archive ) (PDF; 116 kB) [COM / 2012/571]
- ↑ Anna Gabriel: Stress test: Almost all nuclear power plants have defects, October 4, 2012 at diepresse.com.
- ^ After a nuclear accident in Japan: Germany argues over nuclear energy . ( Memento from April 12, 2011 on WebCite ) stern.de , March 12, 2011.
- ↑ Press statements from Chancellor Angela Merkel and Federal Foreign Minister Guido Westerwelle on the consequences of the natural disasters in Japan and the effects on German nuclear power plants . ( Memento from March 25, 2011 on WebCite ) Press and Information Office of the Federal Government, March 14, 2011, accessed on March 25, 2011.
- ↑ Gov't to review safety at nuclear plants: Ramesh ( Memento from April 12, 2011 on WebCite ) (English). The Times of India , March 15, 2011.
- ↑ Karachi, Chashma N-plants safe: PAEC ( Memento from April 12, 2011 on WebCite ) (English). Pakistan Today, March 16, 2011
- ↑ Putin orders review of Russian nuclear plans ( Memento April 12, 2011 on WebCite ). Reuters , March 15, 2011.
- ↑ a b Spain orders review of nuclear power plants - CNN.com ( Memento April 12, 2011 on WebCite ). CNN , March 16, 2011.
- ↑ Israel's Netanyahu says rethinking nuclear power ( Memento April 12, 2011 on WebCite ). Reuters , March 17, 2011.
- ↑ Construction freeze: China puts ambitious nuclear plans on hold . ( Memento from April 12, 2011 on WebCite ) Spiegel Online, March 16, 2011.
- ↑ Swiss nuclear power plants must check their systems immediately . ( Memento from April 12, 2011 on WebCite ) In: NZZ Online . Neue Zürcher Zeitung, March 19, 2011.
- ↑ Switzerland: Phase out nuclear power by 2034. Focus Online, May 25, 2011, accessed on June 23, 2011.
- ↑ France sees lessons from Japan nuclear crisis ( Memento from April 12, 2011 on WebCite ). In: reuters.com . Reuters , March 16, 2011.
- ^ Aubrey Belford: Indonesia Still Intent on Building Nuclear Power Plants - NYTimes.com ( Memento April 12, 2011 on WebCite ). In: Print edition of March 18, 2011 . The New York Times , March 17, 2011.
- ↑ Japan: Netherlands react calmly . ( Memento from April 12, 2011 on WebCite ) In: NiederlandeNet . Westfälische Wilhelms-Universität Münster , March 15, 2011.
- ↑ Turkey's Erdogan Pays Visit To Tatarstan ( Memento April 12, 2011 on WebCite ) (English). Radio Free Europe / Radio Liberty, March 17, 2011.
- ↑ Vietnam to go ahead with nuclear plans ( Memento from April 12, 2011 on WebCite ) (English). GlobalPost , March 20, 2011.
- ↑ Marieluise Beck : The madness continues: Belarus and Russia sign nuclear deal . ( Memento from April 19, 2011 on WebCite ) April 4, 2011.
- ↑ Obama delivers a statement on Japan: Speech Transcript ( Memento April 12, 2011 on WebCite ). In: projects.washingtonpost.com . The Washington Post , March 17, 2011.
- ↑ Italy Approves Nuclear Pause (English). In: online.wsj.com . The Wall Street Journal , March 23, 2011, accessed May 7, 2011.
- ↑ When the desire to leave grows. In: Frankfurter Allgemeine Zeitung , June 6, 2010. Retrieved June 7, 2011.
- ↑ Fundamental Policy for the Reform of TEPCO Nuclear Power Organization (PDF), October 12, 2012, accessed April 9, 2014.
- ^ Martin Fackler: Japan Power Company Admits Failings on Plant Precautions . In: The New York Times , October 12, 2012. Retrieved October 13, 2012.
- ^ Aaron Sheldrick: Fukushima operator must learn from mistakes, new adviser says , Reuters. October 12, 2012. Retrieved October 13, 2012.
- ^ A b Mari Yamaguchi: Japan utility agrees nuclear crisis was avoidable . In: Associated Press , Boston.com, October 12, 2012. Archived from the original on October 5, 2013. Retrieved October 13, 2012.
- ^ Japanese nuclear plant operator admits playing down risk . In: CNN Wire Staff , CNN, October 12, 2012. Retrieved October 13, 2012.
- ↑ Energy Commissioner Oettinger. One billion euros in liability for nuclear accidents. In: Frankfurter Allgemeine Zeitung , October 31, 2013. Accessed November 1, 2013.
- ↑ Uniform insurance. Oettinger demands liability for nuclear power plants . In: Focus , October 31, 2013. Accessed November 3, 2013.
- ↑ EU Commissioner calls for compulsory insurance across Europe. Oettinger seals the end of nuclear power. In: n-tv , October 31, 2013. Accessed November 3, 2013.
- ↑ 147/1961: 原子 力 損害 の 賠償 に 関 す る 法律 , English: Act on Compensation for Nuclear Damage ( Memento of April 9, 2011 in the Internet Archive ); PDF; 76 kB, Section 3
- ↑ Natural disaster exemption not to apply to Tokyo Electric: Edano ( Memento from April 12, 2011 on WebCite ) (English). Kyodo News, March 25, 2011, accessed March 25, 2011.
- ↑ Law 147/1961, Section 7
- ↑ Natalie Obiko Pearson and Carolyn Bandel: Atomic Cleanup Cost Goes to Japan's Taxpayers, May Spur Liability Shift ( Memento April 12, 2011 on WebCite ) (English). In: bloomberg.com . March 23, 2011.
- ↑ Law 147/1961, Section 16
- ↑ Swiss Re provides estimate of its claims costs from Japan earthquake and tsunami ( Memento from May 15, 2011 on WebCite ) (English, pdf). Swiss Re, March 21, 2011 (PDF; 115 kB).
- ↑ Munich Re estimates claim burden from earthquake in Japan at around € 1.5bn ( Memento from May 15, 2011 on WebCite ) Munich Re, March 22, 2011.
- ^ Payment of Temporary Compensation for damages caused by evacuation ( Memento from April 15, 2011 on WebCite ). Tepco, April 15, 2011.
- ↑ Live ticker on the nuclear disaster in Japan . ( Memento from April 15, 2011 on WebCite ) Financial Times Deutschland, April 15, 2011, accessed April 15, 2011.
- ↑ Fukumoto Masao: How difficult it is to renovate a house . In: Strahlentelex with ElectrosmogReport . No. 746 -747 / Volume 32, February 1, 2018, ISSN 0931-4288 , p. 5 ( online [PDF; 469 kB ; accessed on December 12, 2019]).
- ↑ TEPCO urged to compensate farm and fishery producers, evacuees ( Memento of April 29, 2011 on WebCite ). Kyodo News, April 28, 2011, accessed April 29, 2011.
- ^ Status of TEPCO's Facilities and its services after Tohoku-Taiheiyou-Oki Earthquake (as of 9:00 AM) . ( Memento from April 27, 2011 on WebCite ) Tepco, March 25, 2011.
- ↑ Tokyo Electric to scrap 4 reactors at crippled nuclear plant ( Memento April 9, 2011 on WebCite ). Kyodo News
- ↑ Tepco needs money for repairs . ( Memento from April 12, 2011 on WebCite ) FAZ, March 23, 2011.
- ↑ Live ticker on the disaster in Japan . ( Memento from April 12, 2011 on WebCite ) Financial Times Deutschland, April 12, 2011, accessed April 12, 2011.
- ↑ Gov't to help TEPCO pay for nuke crisis damages if survival at risk ( Memento from April 23, 2011 on WebCite ) (English). Kyodo News, April 23, 2011, accessed April 23, 2011.
- ↑ TEPCO chief asks gov't to help in paying damages ( Memento from November 6, 2013 in the Internet Archive ) Reproduction of the Kyodo News from May 10, 2011 at www.istockanalyst.com, accessed on October 1, 2012.
- ^ Outline of the Act to Establish the Nuclear Damage Compensation Facilitation Corporation ( Memento from December 20, 2011 on WebCite ) (English, pdf). METI , August 2011, accessed December 21, 2011.
- ↑ Japan approves compensation fund for Fukushima ( Memento from December 20, 2011 on WebCite ). Zeit Online, August 3, 2011.
- ↑ Nuclear operators to pay 7 billion yen to compensation body ( Memento of December 21, 2011 on WebCite ). Asahi Shimbun, September 8, 2011.
- ↑ Shimizu Masataka: FY2010 Year-end Earnings Results, Presentation Material ( Memento from May 21, 2011 on WebCite ) (English, pdf). Tepco, May 20, 2011. p. 9.
- ^ Announcement of Changes of Directors ( Memento of May 25, 2011 on WebCite ). Tepco, May 20, 2011.
- ↑ Toshio Nishizawa: FY2011 2nd Quarter Earnings Results (April 1 - September 30, 2011) Presentation Material ( Memento from December 20, 2011 on WebCite ) (English, pdf). Tepco, November 4, 2011, accessed December 21, 2011.
- ↑ FAZ.net June 30, 2017 / Patrick Welter: Tepco managers declare themselves innocent
- ↑ Court convicts government of Fukushima disaster
- ^ Acquittal for ex-manager of the Fukushima nuclear power plant. In: bernerzeitung.ch . September 19, 2019. Retrieved September 19, 2019 .
- ↑ Felix Lill: Manga from the restricted area. Badische Zeitung , March 7, 2015, accessed on March 4, 2017 .
- ^ Fifth anniversary of the disaster in Fukushima: Interview with "Reactor 1F" author Kazuto Tatsuta. Carlsen Verlag , March 9, 2016, accessed March 4, 2017 .
- ↑ Fukushima - Living with Disaster. Bayerischer Rundfunk on YouTube , March 12, 2016, accessed on January 10, 2018 .
- ↑ Klaus Eberhartinger: The world today is a monster ball. Focus online , January 30, 2015, accessed February 5, 2017 .
- ↑ Mrs. Fuckushima. www.verunsicherung.de, January 30, 2015, accessed on February 5, 2017 .
- ↑ Greetings from Fukushima - A film by Doris Dörrie. www.gruesseausfukushima.de, 2016, accessed on February 7, 2019 .
- ↑ u. a. Human Against Radiation , Quarks & Co from March 22, 2011 on YouTube , accessed on February 14, 2017.
- ↑ The Fukushima Disaster , Quarks & Co of March 6, 2012 on YouTube , accessed on February 14, 2017.
- ↑ Fukushima - End Not in Sight , Quarks & Co, March 10, 2015 on YouTube , accessed on February 14, 2017.
- ↑ Reinhart Brüning: What happened during the reactor disaster and in the four years that followed , Quarks & Co , WDR , March 3, 2015.
| INES 7 |
Chernobyl (1986) | Fukushima Daiichi (2011) |
 |
| INES 6 |
Kyschtym (1957) |
|
| INES 5 |
Chalk River (1952) | Sellafield (1957) | Santa Susana (1959) | Beloyarsk (1977) | Harrisburg (1979) | Chernobyl (1982) | Vladivostok (1985) | Goiânia (1987) |
Coordinates: 37 ° 25 '17 " N , 141 ° 1' 57" E