Fukushima Daiichi nuclear power plant

from Wikipedia, the free encyclopedia
Fukushima Daiichi nuclear power plant
Photo-request.svg
Image wanted BW
location
Fukushima Daiichi Nuclear Power Plant (Fukushima Prefecture)
Fukushima Daiichi nuclear power plant
Coordinates 37 ° 25 '17 "  N , 141 ° 1' 57"  E Coordinates: 37 ° 25 '17 "  N , 141 ° 1' 57"  E
Country: JapanJapan Japan
Data
Owner: Tōkyō Denryoku
Operator: Tōkyō Denryoku
Project start: 1966
Commercial operation: March 26, 1971

Decommissioned reactors (gross):

6 (2,812 MW)

Planning set (gross):

2 (2,760 MW)
Energy fed in in 2009: 29,891 GWh
Energy fed in since commissioning: 877,692 GWh
Website: www.tepco.co.jp
Was standing: March 21, 2011
The data source of the respective entries can be found in the documentation .
f1

Fukushima Daiichi , Fukushima Dai-ichi or Fukushima I [ ɸɯ̥ˈkɯɕima ] ( Japanese 福島 第一 原子 力 発 電 所 Fukushima Dai-ichi Genshiryoku Hatsudensho pronunciation ? / I 'Fukushima nuclear power plant No. 1') was with six reactor blocks and up to 4.5 Gigawatts of net electrical output from one of the most powerful nuclear power plants in Japan . It is located directly on the Pacific in Fukushima Prefecture , 250 kilometers northeast of Tokyo . The reactor units 1 to 4 are located in the area of Ortkuma.Audio file / audio sample

Fukushima Daiichi went into operation in 1971 and is therefore the oldest nuclear power plant of the former state-owned Tōkyō Denryoku (Tokyo Electric Power Company - TEPCO), which also operates the Fukushima Daini (Fukushima II) nuclear power plant twelve kilometers to the south .

The extremely strong earthquake in March 2011 followed by a huge tsunami led to failures in safety systems and irreparable damage to reactor units 1 to 4 with core meltdown and the release of radioactive substances. The Japanese government then decided that the power plant with the 4 blocks should be dismantled by 2040 at the latest. In December 2013 it was announced that Tepco is also giving up reactors 5 and 6, which had survived the earthquake and tsunami in 2011. Blocks 5 and 6 belong to the Futaba to the north and were shut down on January 31, 2014.

Construction

Aerial photo from 1975, reactor blocks 4 to 1 (from left to right) on the left in the picture, block 5 on the right, next to it block 6 under construction

Each of the six power plant blocks is based on a boiling water reactor from the BWR / 3 to BWR / 5 series designed by General Electric . Block 4 was built by Hitachi , the rest by General Electric and / or Toshiba . The reactor cores of the blocks 1-5 are in an as Mark I designated containment (containment) of the first generation of General Electric, which in turn, together with other systems in the reactor building; On the sea side, there is a building with the turbines for power generation. In block 6, a further developed safety container of the Mark II type was used. The construction of two additional advanced boiling water reactors did not go beyond the planning.

The reactor building of a block consists largely of a concrete structure that surrounds the reactor core and the containment (see figure in the section “Storage of fuel assemblies” ). The concrete walls serve primarily to shield against gamma radiation ( biological shield ) and to protect the internal installations from external mechanical influences. In the upper area of ​​the concrete structure there is a decay pool for spent fuel elements and a storage pool for new fuel elements. A loading shaft leads down to the ground floor.

The upper part of the building is a steel structure. Here is a working area ( refueling floor ) with a loading crane for filling the reactor core with fuel elements . The concrete structure and steel shell form the second containment ( secondary containment ).

The system draws its cooling water from the sea and has a total area of ​​around 3.5 km². The blocks 1/2, 3/4 and 5/6 each form a structural unit. As of August 21, 2010, in addition to 516 uranium fuel elements, 32 MOX fuel elements with a mixture of uranium oxide and plutonium oxide were in use in Unit 3 .

There are also several storage facilities for radioactive waste, an administration building, various environmental monitoring facilities and a sports field on the site.

Data of the reactor blocks

Reactor block Reactor type,
core (containment) 		Manufacturer net
power 		Gross
performance 		thermal performance start of building Netzsynchro-
Organization 		business
Fukushima I-1 Boiling water reactor
BWR / 3 (Mark I) 		General Electric 439 MW 460 MW 1380 MW July 28, 1967 17th November 1970 March 26, 1971-11. March 2011 (f1)
Fukushima I-2 Boiling water reactor
BWR / 4 (Mark I) 		General Electric / Toshiba 760 MW 784 MW 2381 MW June 9, 1969 December 24th 1973 July 18, 1974-11. March 2011
Fukushima I-3 Boiling water reactor
BWR / 4 (Mark I) 		Toshiba 760 MW 784 MW 2381 MW December 28, 1970 October 26, 1974 March 27, 1976-11. March 2011
Fukushima I-4 Boiling water reactor
BWR / 4 (Mark I) 		Hitachi 760 MW 784 MW 2381 MW February 12, 1973 February 24, 1978 October 12, 1978-30. November 2010
Fukushima I-5 Boiling water reactor
BWR / 4 (Mark I) 		Toshiba 760 MW 784 MW 2381 MW May 22, 1972 September 22, 1977 April 18, 1978-11. March 2011 or January 31, 2014 (f2)
Fukushima I-6 Boiling water reactor
BWR / 5 (Mark II) 		General Electric / Toshiba 1067 MW 1100 MW 3293 MW October 26, 1973 4th May 1979 October 24, 1979-11. March 2011 or January 31, 2014 (f2)
Fukushima I-7 Advanced boiling water reactor Toshiba 1325 MW 1380 MW abandoned (f3)
Fukushima I-8 Advanced boiling water reactor Toshiba 1325 MW 1380 MW abandoned (f3)
(f1)Reactor unit 1 should be shut down in early 2011 . In February 2011, however, the Japanese nuclear regulatory authority NISA extended the term by ten years.
(f2)According to the operator, reactor blocks 5 and 6 are still functional. On March 14, 2011, the plan was held to continue operating them until 2018 and 2019 respectively. On March 20, 2011, the Japanese government announced that it wanted to completely shut down the plant. Government spokesman Yukio Edano said it was extremely unlikely to be restarted.

On December 18, 2013, Tepco applied for the shutdown of units 5 and 6 by January 31, 2014.

(f3)The reactor blocks 7 and 8 should be built by Toshiba from 2012. In May 2011, Tepco abandoned this plan, citing reservations of the local population as the reason.

Storage of fuel assemblies

Structure of a reactor building with Mark I containment, the cooling pool shown in blue
Reactor Buildings 1 and 2 (1999)
The boundary between the concrete and the attached (two-part) steel structure can be seen on the shell of reactor block 1.

There are seven decay basins within the facility for the interim storage of used (spent) fuel elements . One of these basins is located on the second to third floors of the respective reactor building; they are protected neither by the primary containment nor by the concrete shell of the secondary containment. Their total capacity is 8,310 fuel elements. In addition, each reactor building also contains a storage pool for new fuel elements. In addition, since 1997 there has been a separate decay pool for a maximum of 6,840 fuel elements right next to reactor units 3 and 4. In addition, since 1995 up to 900 additional elements can be stored dry in special containers.

According to the operator, 41% of the six decay basins in the reactor blocks were used, the separate basin 92% and the dry storage facility 45%. The amount of fuel stored was given as a total of 10,149 fuel elements or 1,760 tonnes of uranium, the new production of spent elements with around 700 per year. Thus in March 2010 the spent fuel elements from 14 ½ years of operation were stored on the power plant site.

In March 2011, a total of around 14,700 fuel elements with a mass of nuclear fuel of around 2,500 tons were stored on the site of the power plant. The following number of fuel elements was in the reactor cores and the individual basins:

Storage location Fuel elements
in the reactor core 		Fuel elements
in the spent fuel		 unused
fuel assemblies 		Volume of the
fountain
Block 1 400 292 100 1,020 m³
Block 2 548 587 28 1,425 m³
Block 3 548 514 52 1,425 m³
Block 4 0 1,331 202 1,425 m³
Block 5 548 946 48 1,425 m³
Block 6 764 876 64 1,497 m³
separate basin 6,375 3,828 m³
total 2,808 10,921 494 12,045 m³

A single fuel assembly consists of 63 fuel rods, each 3685 mm long and weighs around 170 to 173 kg, depending on the reactor.

Power plant type risks

The containment Mark I of General Electric, which was used in Fukushima I has, according to various experts insufficient capacity to reduce pressure inside the containment. A security expert from the Atomic Energy Commission (AEC) in the USA therefore called in 1971 to end and ban the installation of this system. The AEC leadership rejected a ban in 1972 because it could end the US nuclear industry. In 1976, three senior engineers at General Electric quit Mark I over safety concerns . One of them, Dale Bridenbaugh, considered the Mark I's design inadequate in major accidents, suggested a construction freeze during fault analysis, and resigned after General Electric rejected it. To the best of his knowledge, however, the concept flaws he pointed out in Fukushima I were taken into account. The containment was not a direct cause of the accident, but in the event of an earthquake and tsunami it was less “forgiving” than other reactor types.

In 1985, the Nuclear Regulatory Commission (NRC) responsible for nuclear safety in the United States determined that the Mark I would fail in the first hours after a core meltdown; an NRC representative thought that failure was 90% likely in 1986. As a result, a valve system was developed and built into all Mark I containers, which allows radioactive water vapor to be released into the atmosphere unfiltered.

In a 1992 BBC documentary series, filmmaker Adam Curtis pointed out risks in the cooling system of boiling water reactors such as those in Fukushima I that had been known since 1971.

The construction of the power plant concept adopted in Fukushima I, in which there is a cooling basin next to the containment, has been increasingly criticized since the accidents in March 2011, as it increases the risk of damage and radioactive emissions considerably. In Fukushima these basins were used excessively for the storage of old fuel assemblies. Japanese nuclear supervisors thought this was a wrong decision; Investments in safer accommodation options have been neglected.

According to investigations by the Japanese nuclear regulatory authority and the International Atomic Energy Agency , these risks played no role in the accidents in March 2011 :

  • The emergency cooling systems and the pressure reduction in the containment functioned perfectly in all reactors as long as the power supply existed, with the exception of a reserve system (HPCI) in block 3 that was probably damaged by the earthquake . Without a power supply to control valves, a more powerful pressure reduction system or a more reliable emergency cooling system would be useless been.
  • The additional valves for unfiltered ventilation of the containment had been retrofitted in Fukushima and were used in units 1 to 3 during the accidents. It turned out to be a hindrance that even with this improved system, a complete power failure was not considered.
  • Contrary to initial assumptions, the situation in the decay basin was not critical: the basins remained intact despite earthquakes, explosions and reactor damage; the fuel elements stored in it were most likely not or hardly damaged.

Construction defects of the power plant

After the disaster in March 2011, various design flaws of this power plant became known, which engineers, seismologists and regulatory authorities had pointed out for a long time.

According to the engineer Shiro Ogura, who was involved in the construction of five of the six units, the construction plans designed for US locations were uncritically adopted by General Electric for the construction of reactor unit 1 from 1967 onwards. Only with the other reactor blocks was this construction adapted to the Japanese conditions. The risk of tsunamis at this coastal location was also not taken into account. It was not until 2007 that this was taken into account and the design specifications revised. However, according to the operating company's specifications, the cooling systems were only designed for earthquakes with a maximum strength of 8 . Nobody thought a stronger earthquake was possible. He never criticized the lack of security precautions.

The cliff, which was originally around 35 meters high on the construction site, was removed down to only 10 meters (blocks 1 to 4) or 13 meters (blocks 5 and 6) for the construction of the power plants. According to publications by Tepco engineers from the late 1960s, one of the main reasons for this was the cost savings for the seawater pumps due to the lower delivery head. After the accident in March 2011, Masatoshi Toyota, Tepco's former vice-president and in this role mainly responsible for the construction of Unit 1, said another reason for the removal was greater earthquake resistance, as the remaining bedrock was more stable than the removed surface layer. In fact, it is common practice to place nuclear power plants directly on the natural rock to increase earthquake security. As a third reason, Toyota named the planned delivery of the 500-ton pressure vessels by ship. The tsunami of March 11, 2011 reached a height of about 14 to 15 meters above sea level.

The engineer Mitsuhiko Tanaka played a leading role in the construction of a steel pressure boiler for Hitachi in 1974, which is now located in reactor block 4. In March 2011, he stated that the boiler had warped during manufacture. He had helped cover up this in order to avoid the legally required scrapping of the $ 250 million boiler. For this he received a high annual bonus and a medal of merit from the company. In 1988, two years after the Chernobyl disaster , he reported the boiler's construction error to the government of Japan. Hitachi denied his report and the government refused to investigate. Since meeting Tanaka in 1988, Hitachi insisted that the boiler was not a safety issue.

During the construction of Fukushima I, the emergency generators were installed in the basement of the turbine building on the sea side of the reactor building. These turbine buildings were not adequately protected from water, so that the tsunami inundated the emergency power generators in them and they failed, as did the seawater cooling pumps. Unlike in power plants built later, both the emergency power generators and the seawater cooling pumps remained in the unprotected place, although an internal Tepco investigation assessed this as a safety risk. According to statements by former Tepco employees, their placement was not taken into account in the 1970s and 1980s, when the earthquake protection of the reactor buildings was improved, as they did not have space to accommodate the emergency power generators. The cooling pumps could only have been laid underneath together with various pipes. Nobody considered the necessary renovation measures at the time; for reasons of cost and in order not to have to admit wrong decisions. Fukushima I was a "practice course for Toshiba and Hitachi to learn about General Electric's power plant design on the basis of trial and error ".

The installation of a system to prevent fatal oxyhydrogen explosions was worked out and offered by the Swiss engineering company Elektrowatt in 1992-96, but was never carried out. (See also the so-called potter's candle .)

Insufficient protection against earthquakes and tsunamis

In 1990, the NRC also warned of the failure of emergency generators and thus of the cooling systems of power plants located in areas prone to earthquakes. She identified this failure as one of the most likely risks. NISA cited this report in 2004. According to Jun Tateno, a former scientist with the Japan Atomic Energy Agency, Tepco did not respond to these warnings or take appropriate action. After the earthquake on March 11, 2011, all twelve available emergency power generators in Fukushima I worked perfectly.

In 2005 and 2007 there were accidents in three Japanese nuclear power plants due to earthquakes, the strength of which was not taken into account in the design of the reactors. The seismologist Katsuhiko Ishibashi analyzed these cases and warned in 2007 of the "fundamental vulnerability" of Japanese nuclear power plants to earthquakes, the increasing strength and frequency of which had been seriously underestimated in the construction of many power plants in the 1970s. At that time, Ishibashi called for fundamental improvements to the safety standards for Japanese nuclear power plants. After the 2011 accidents, he criticized that nuclear policy had not learned anything since 2007. The Japanese energy industry and the academic elite also ignored the warnings. However, according to General Electric, all six reactors are said to have met the Nuclear Regulatory Commission's safety requirements for earthquakes.

After the earthquake of July 16, 2007 with a magnitude of 6.6, Tepco had the locations of its power plants geologically checked to determine their resilience in the event of earthquakes and tsunamis. As a result of this test, a protective wall 5.7 m high against tsunamis was built at Fukushima I. However, some emergency power generators were located directly on the sea shore at ground level and were insufficiently protected against flooding.

Engineer Masashi Goto, who was involved in the construction of the Fukushima I reactors, said the government's safety guidelines did not require a replacement for the failure of emergency generators. They only asked the companies to make a voluntary effort to build the containment boilers earthquake-proof. You would never have expected a worst-case scenario. In 2009, the Atomic Safety Commission of Japan called for a stationary fire brigade to be available at every nuclear power plant in order to be able to fight fires immediately after earthquakes. Such a fire brigade was available in Fukushima I and provided valuable help with the rescue measures.

Tatsuya Ito, a former Fukushima Prefectural MP in the national parliament, said he had warned Tepco's board of directors at least 20 times in direct meetings about the danger of the tsunami since 2003. In 2002, a report by the Japan Society of Civil Engineers requested by the company itself described the scenario of a tsunami following a 9.5 magnitude earthquake. In 2005 he wrote a letter to the President of Tepco about this. However, the company disregarded all warnings.

The seismologist Yukinobu Okamura , head of the Active Fault and Earthquake Research Center at AIST , had warned a government body in 2009 about a devastating tsunami like the one from 869 , but Tepco rejected the warning "as insufficiently founded".

In a parliamentary question on May 26, 2010, NISA representative Nobuaki Terasaka admitted that a complete power failure could partially melt the reactor cores and thus make it impossible to cool their nuclear fuel rods. Therefore, the operators would have secured the power plants with many backup power sources that should compensate for a power failure within a few hours. Jun Tateno explained that with better protection of these replacement generators against exceptionally strong earthquakes and high tsunamis, the accidents of March 2011 would have been avoidable.

In its investigation report on the accidents of March 2011, the IAEA clearly criticized the safety requirements of the Japanese authorities. The guidelines published by the Nuclear Safety Commission of Japan in 2006 after years of work are non-binding and contain no useful methods for re-testing the power plants. There were no effective regulations for the tsunami safety of nuclear power plants.

Incidents and a lack of controls

In 2002 it became known that company representatives had falsified repair reports on Tepco's nuclear power plants for over 16 years and had concealed security-related incidents from the supervisory authorities in hundreds of cases. Thereupon the board of directors of Tepco admitted the fakes, resigned and was replaced by the government. All Tepco nuclear power plants were shut down and checked for three weeks. Fukushima I was approached again on May 16, 2003.

Since the change of management in 2002, there have been at least six emergency shutdowns in Fukushima I and a seven-hour critical reaction in reactor block 3. These incidents were also kept silent.

On May 25, 2008, several emergency cooling systems failed during a test in reactor block 6. NISA classified the incident as a “disruption” (level 1) on the international nuclear incident rating scale .

As it became known on March 21, 2011, on March 1, the NISA had detected significant deficiencies in Tepco's inspection and maintenance: 33 devices and machines in Fukushima I, including the cooling pumps, diesel generators and temperature control valves of the reactor blocks, had not been carefully controlled for eleven years been. NISA had set Tepco until June 2, 2011 to develop a corrective plan.

Accidents from March 11, 2011

Status of reactor blocks 1 to 4 (from right to left) on March 16, 2011 after several explosions and fires

As a result of the Tōhoku earthquake on March 11, 2011 and the subsequent tsunami , the electrical energy supply to the power plant failed, so that the reactor cores and stored fuel rods were insufficiently cooled. This led to a series of accidents with several core meltdowns , in which reactor blocks 1 to 4 were destroyed and considerable amounts of radioactive substances were released. Two workers in the power plant died in the earthquake; at least a hundred received radiation exposures over 100 millisieverts .

First of all, an area within a twenty-kilometer radius with 70,000 to 80,000 residents was evacuated , later a few more distant places with particularly high levels of radioactive contamination were temporarily evacuated . Agricultural products, soil, tap water, sea water and marine animals in a wide area have been contaminated with radioactive substances; in some cases the legal limit values ​​were exceeded many times over.

In the course of the series of accidents, the Japanese nuclear supervisory authority classified the incidents in reactor blocks 1 to 3 on the international rating scale for nuclear incidents, initially provisionally as level 4 ("accident") and then as level 5 ("serious accident"). Later, on the basis of the estimated amount of released radioactive substances, it came to a - still provisional - classification in the maximum level 7 ("catastrophic accident").

photos

  • Reactor Buildings 5 ​​and 6 (1999)

  • Control center (1999)

  • Cooling pool with mirror image of the loading crane (1999)

  • Main entrance (April 2011)

See also

Web links

Commons : Fukushima I Nuclear Power Plant  - Collection of pictures, videos and audio files
 Wikinews: Fukushima I Nuclear Power Plant  - in the news

Individual evidence

  1. ^ Fukushima nuclear plant to be decommissioned: Gov't. Kyodo News, March 20, 2011, archived from the original April 10, 2011 ; accessed on March 21, 2011 (English).
  2. ↑ Earthquake Report - JAIF, No. 291 ( Memento from December 15, 2011 on WebCite ) (English, pdf). JAIF / NHK, December 15, 2011, archived from the original (PDF; 97 kB), retrieved on December 15, 2011.
  3. ↑ Nicola Kuhrt: Fukushima nuclear ruin: Operator Tepco wants to shut down all reactors permanently. In: Spiegel Online . December 18, 2013, accessed December 19, 2013.
  4. ↑ GRS overview table ( Memento of the original from April 6, 2011 on WebCite ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 50 kB), accessed on April 7, 2011 @1@ 2Template: Webachiv / IABot / fukushima.grs.de
  5. ↑ Analysis of safety containers by M. Ragheb, NUCLEAR, PLASMA AND RADIOLOGICAL ENGINEERING, University of Illinois at Urbana-Champaign ( Memento of the original from May 15, 2011 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed April 19, 2011 @1@ 2Template: Webachiv / IABot / netfiles.uiuc.edu
  6. ↑ MOX fuel loaded into Tokyo Electric's old Fukushima reactor. Japan Today, August 22, 2010; Archived from the original on May 2, 2011 ; accessed on March 13, 2011 (English).
  7. ↑ Proof of plutonium on the site of the Fukushima Daiichi nuclear power plant . GRS. Archived from the original on April 9, 2011. Retrieved April 4, 2011.
  8. ↑ April 7th, 2011 Fukushima Dai-ichi Monitoring Data. (PDF) April 7, 2011, archived from the original on April 10, 2011 ; accessed on April 10, 2011 (English, site plan on page 6).
  9. ↑ Japan: Nuclear Power Reactors - Alphabetic. In: Power Reactor Information System . IAEA , accessed March 12, 2011 .
  10. ↑ a b Nuclear Power in Japan. World Nuclear Association, February 24, 2011, accessed March 18, 2011 .
  11. ↑ Mari Yamaguchi, Jeff Donn: Japan quake causes emergencies at 5 nuke reactors. In: Forbes Magazine . Associated Press , March 11, 2011, accessed March 13, 2011 .
  12. ↑ Crisis management remains chaotic. ( Memento from May 22, 2011 on WebCite ) ORF, March 30, 2011, archived from the original , accessed on May 22, 2011: "The two other reactors are still operational."
  13. ↑ Nuke Database System: Fukushima Daiichi-5. (No longer available online.) Izobraževalni center za jedrsko tehnologijo, archived from the original on March 17, 2011 ; accessed on March 14, 2011 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.icjt.org
  14. ↑ Nuke Database System: Fukushima Daiichi-6. (No longer available online.) Izobraževalni center za jedrsko tehnologijo, archived from the original on March 17, 2011 ; accessed on March 14, 2011 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.icjt.org
  15. ↑ a b Fukushima nuclear plant to be decommissioned: Gov't. Kyodo News, March 20, 2011, accessed March 21, 2011 .
  16. ↑ Japan: Fukushima-Daiichi-5 and -6 are shut down. nuklearforum.ch, accessed on January 9, 2014 .
  17. ↑ Toshiba's Nuclear Energy Activities (PDF; 1.5 MB) Toshiba. December 11, 2010. Retrieved April 5, 2011.
  18. ↑ Decommissioning of Fukushima Daiichi Nuclear Power Station Units 1 to 4 and Abolishment of Construction Plans for Units 7 and 8. Tepco, May 20, 2011, archived from the original on May 20, 2011 ; accessed on May 21, 2011 .
  19. ↑ Reactor Concepts Manual - Boiling Water Reactor (BWR) Systems. (PDF; 3.5 MB) Accessed March 19, 2011 (English).
  20. ^ A b Integrity Inspection of Dry Storage Casks and Spent Fuel at Fukushima Daiichi Nuclear Power Station. (PDF; 1.9 MB) November 16, 2010, accessed on March 16, 2011 (English): “Approx. 700 spent fuel assemblies are generated every year. " Information on dry storage from page 12
  21. ↑ Brief overview of the current security situation. (PDF; 24 kB) March 19, 2011, accessed on March 19, 2011 .
  22. ↑ More on Spent Fuel Pools at Fukushima ( English ) All Things Nuclear. March 21, 2011. Archived from the original on April 9, 2011. Retrieved March 22, 2011.
  23. ↑ a b Technical data Fukushima No. 1 in normal operation (pdf; 50 kB) GRS. Archived from the original on April 6, 2011. Retrieved April 7, 2011.
  24. ↑ Brief overview of the current security situation (pdf; 24 kB) Society for Plant and Reactor Safety . March 19, 2011. Archived from the original on April 9, 2011. Retrieved on March 19, 2011.
  25. ^ Fukushima Nuclear Accident Update Log ( English ) IAEA. March 22, 2011. Archived from the original on April 9, 2011. Retrieved on April 4, 2011.
  26. ↑ Fukushima Accident 2011 ( English ) April 2, 2011. Archived from the original on April 4, 2011. Retrieved on April 4, 2011.
  27. ↑ http://www.oecd-nea.org/sfcompo/Ver.2/Eng/Fukushima-Daiichi-3/index.html
  28. ↑ Paul Gunter, March 1996, Michael Mariotte, March 2011 (Nuclear Information and Resource Service): Hazards of Boiling Water Reactors in the Unites States
  29. ↑ Newsdaily / Reuters, March 15, 2011: Japan reactor design caused GE engineer to quit
  30. ↑ Paul Gunter, March 1996, Michael Mariotte, March 2011 (Nuclear Information and Resource Service): Hazards of Boiling Water Reactors in the Unites States
  31. ^ Adam Curtis: A Is For Atom. In: bbc.co.uk. British Broadcasting Corporation, March 16, 2011, accessed April 2, 2011 ( Pandora's Box , part 6 ).
  32. ↑ Ralf Streck: Emergency cooling problems of Fukushima reactors known since 1971 . In: Telepolis . Heise Zeitschriften Verlag. March 22, 2011. Archived from the original on April 1, 2011. Retrieved on April 1, 2011.
  33. ↑ Christoph Seidler (Der Spiegel, March 16, 2011): Decay basin of German kilns: danger in cobalt blue
  34. ↑ Kevin Krolicki, Ross Kerber (Reuters / The West, March 22, 2011): Special Report: Fuel storage, safety issues vexed Japan plant  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / au.news.yahoo.com  
  35. ↑ a b c d e Additional Report of the Japanese Government to the IAEA ( Memento from December 11, 2011 on WebCite ) (English, pdf, 31 MB). Kantei , September 15, 2011, archived from the original , accessed December 17, 2011.
  36. ↑ a b c Mission Report: The Great East Japan Earthquake Expert Mission ( Memento from June 26, 2011 on WebCite ) (English, pdf). IAEA, June 16, 2011, archived from the original (PDF; 2.8 MB), accessed June 25, 2011.
  37. ↑ Earthquake Report - JAIF, No. 93 ( Memento from May 26, 2011 on WebCite ) (English, pdf). JAIF / NHK, May 26, 2011, archived from the original (PDF; 130 kB), accessed on May 26, 2011.
  38. ↑ Tepco's own security account doesn't mention tsunamis at all.
  39. ↑ Disaster analysis you may not hear elsewhere . Eriko Arita, Japan Times , March 20, 2011.
  40. ^ 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, archived from the original (PDF; 395 kB) on April 11, 2011, accessed on March 30, 2012.
  41. ↑ TEPCO details tsunami damage / Waves that hit Fukushima plant exceeded firm's worst-case projections ( memento of the original from April 10, 2011) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , Report on Daily Yomiuri Online dated April 11, 2011. @1@ 2Template: Webachiv / IABot / www.yomiuri.co.jp
  42. ↑ Fukushima plans site originally was a hill safe from tsunami , Report by Reiji Yoshida and Takahiro Fukada on The Japan Times Online , July 13, 2011.
  43. ↑ Jason Clenfield (Bloomberg, March 18, 2011): Japan Disaster Caps Decades of Faked Reports, Accidents
  44. ↑ Japan Times, March 24, 2011: Defect concealed in Fukushima No. 4 reactor
  45. ^ The 2011 off the Pacific coast of Tohoku Pacific Earthquake and the seismic damage to the NPPs. (PDF) (No longer available online.) NISA, April 4, 2011, archived from the original on May 1, 2011 ; Retrieved on April 13, 2011 (English, location and flooding of the generators under 3-2. Major root cause of the damage , pdf p. 12). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.nisa.meti.go.jp
  46. ↑ Fukushima No. 1 plant designed on 'trial-and-error' basis ( English ) Asahi Shimbun . April 7, 2011. Archived from the original on April 13, 2011. Retrieved on May 19, 2011.
  47. ↑ Swiss engineers had long since warned Fukushima operators
  48. ↑ Makiko Kitamura, Maki Shiraki (Bloomberg, March 16, 2011): Japan's Reactor Risk Foretold 20 Years Ago in US Agency Report
  49. ^ The Guardian, March 12, 2011: Japan ministers ignored safety warnings over nuclear reactors
  50. ↑ Jason Clenfield (Bloomberg, March 18, 2011): Japan Disaster Caps Decades of Faked Reports, Accidents
  51. ^ Richard Gray, Michael Fitzpatrick (Telegraph, March 19, 2011): Japan nuclear crisis: tsunami study showed Fukushima plant was at risk
  52. ↑ Makiko Kitamura, Maki Shiraki (Jakarta Globe, March 18, 2011): Tepco Ignored Warnings About Tsunami Risk, Ex-Lawmaker Says ( Memento of the original from March 20, 2011 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.thejakartaglobe.com
  53. ↑ Earthquake - tsunami - catastrophe at the Fukushima nuclear power plant . In: vdi-nachrichten.com . VDI publishing house. April 1, 2011. Archived from the original on April 1, 2011. Retrieved on April 1, 2011.
  54. ↑ Researcher warned 2 years ago of massive tsunami striking nuclear plant ( English ) Japan Today . March 27, 2011. Archived from the original on April 1, 2011. Retrieved on April 1, 2011.
  55. ↑ Kyodonews, April 3, 2011: Gov't aware of the possibility of reactor core's meltdown before quake
  56. ↑ Japan: Operator starts up reactor again after scandal. (No longer available online.) May 7, 2003, archived from the original on July 15, 2011 ; Retrieved March 12, 2011 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.rp-online.de
  57. ↑ Jason Clenfield (Bloomberg, March 18, 2011): Japan Disaster Caps Decades of Faked Reports, Accidents
  58. ↑ Deviation from the Limiting Conditions for Operation of Unit-5 ( English ) NISA / METI. May 27, 2008. Archived from the original on January 18, 2012. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved May 12, 2011. @1@ 2Template: Webachiv / IABot / www2.jnes.go.jp
  59. ↑ Christoph Neidhart: Fukushima-1: Inadequate maintenance - operator Tepco forged repair logs . Southgerman newspaper. March 21, 2011. Retrieved April 2, 2011.
  60. ↑ Reactor disaster: Fukushima operator sloppy during controls . Spiegel Online . March 21, 2011. Retrieved April 2, 2011.
  61. ↑ Accident at the nuclear power plant: Fukushima operator botched controls. Zeit Online, March 21, 2011, archived from the original on April 1, 2011 ; Retrieved April 2, 2011 .
  62. ↑ Two dead found in the Fukushima nuclear power plant . Focus. April 3, 2011. Archived from the original on April 11, 2011. Retrieved on April 11, 2011.
  63. ↑ Enhancing controls of internal exposures at Fukushima Daiichi Nuclear Power Station ( Memento from December 11, 2011 on WebCite ), Tepco, September 30, 2011, archived from the original (PDF; 87 kB), accessed on December 11, 2011. Table on page 5.
  64. ^ 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 ( English , pdf) NISA / METI. April 12, 2011. Archived from the original on April 12, 2011. Retrieved on April 12, 2011.