New Safe Confinement
As a New Safe Confinement (mutatis mutandis New safe enclosure; NSC ), the new protective case over the old sarcophagus of the Chernobyl nuclear power plant called.
The protective cover is one of several construction projects on the site around the former nuclear power plant, all of which aim to remove radioactive fuels under safe conditions, process radioactive waste and transform the entire facility into a technical system that is harmless to the environment.
Old "sarcophagus"
After the Chernobyl nuclear disaster in April 1986, a provisional construction was hastily built over several months around the building of the damaged reactor block, known as the “ sarcophagus ”: it was supposed to prevent radioactive particles from entering the atmosphere in an uncontrolled manner.
Due to the high level of radioactivity and the extreme time pressure under which the work had to be carried out, it was not possible to build a structure that would last for a long time: On the one hand, the destroyed reactor had to be enclosed as quickly as possible, on the other hand, it was important that the Limit workers in the radioactive area. Therefore, a structure was built that consisted as much as possible of prefabricated steel parts that were prepared at a greater distance and then mounted over the reactor; Then the prepared steel walls were partly poured with concrete, and it was also necessary to use materials that could be obtained as quickly as possible, such as pipeline tubes for the roof structure. Inevitably, the construction of the sarcophagus also had to include parts of the reactor building that had remained standing, the stability of which could not be checked. Likewise, concrete foundations for the sarcophagus were poured onto the rubble of the destroyed reactor without it being possible to determine the load-bearing capacity of this underground. To make matters worse, the immediately adjacent, undamaged power plant block should continue to be operated, so the previously connected rooms and plant components had to be separated when the sarcophagus was built.
In November 1986 the sarcophagus was completed, which consisted of 7,000 tons of steel and 410,000 m³ of concrete. Over time, the sarcophagus began to leak and steel girders rusted, which could lead to the collapse of the entire structure if they gave way. In addition, there are holes in the roof through which water can penetrate into the building below. This contaminated water seeps into the ground under the reactor block.
In December 1988, Soviet scientists announced that the sarcophagus had an intended life of only 20 to 30 years. Therefore, in 1992, new solutions began to be developed to prevent another catastrophe. The examinations at the time led to the conclusion that a new sarcophagus had to be built over the old one. This project was regulated in a Ukrainian law and passed in June 1997 at a G7 meeting as part of the Shelter Implementation Plan (SIP) .
New "sarcophagus"
Goal setting
The new protective cover has been designed for a lifetime of 100 years. The five main goals are:
- To limit any radiation effects on the public, staff and the environment during normal operation and in emergencies,
- limit the spread of ionizing radiation and radioactive substances,
- to enable a controlled dismantling of all structures within the protective cover,
- the monitoring of all status parameters as well
- to offer physical protection, for example preventing unauthorized access.
Among other things, about 150 tons of partially melted nuclear fuel are to be recovered from the interior of the old sarcophagus. To reduce the corrosion of the steel structure, the humidity inside the double shell should be controlled and kept at a maximum of 40 percent.
Concept and costs
The overall concept for the new protective cover and the associated projects were discussed in March 2004 in Slavutytsch between Ukrainian scientists. On July 5, 2004, the Cabinet of Ministers of Ukraine adopted the draft as Order No. 443-r . The total cost of implementing the Shelter Implementation Plan is estimated by the European Bank for Reconstruction and Development (EBRD) to be more than € 2 billion, which is spent by more than 40 countries.
On August 10, 2007, following a two-phase international tender, the Novarka consortium, led by the French construction companies VINCI Construction Grands Projets and Bouygues Travaux Publics, was awarded the contract.
The EBRD also set up the Chernobyl Shelter Fund in 1997 to help Ukraine implement the SIP. In addition to the European Union, there are 25 other countries that pay the contributions.
The operating costs of the protective cover should amount to around 8 million euros annually.
Construction phases and dates
Construction of the new protective cover began at the end of 2010, as some preliminary work was necessary beforehand. Above all, the old sarcophagus had to be equipped with a ventilation system. In addition, a steel structure was erected on the west side of the old sarcophagus in 2008, which carries 80 percent of the weight of the roof.
All lifting work was completed in October 2014.
After completion, the protective cover should have a span of 257 m, a length of 162 m and a height of 108 m. It should be able to withstand temperatures from −30 ° C to +50 ° C, a magnitude 6 earthquake and a level 3 tornado . 81,000 m³ of concrete will serve as the foundation, while the construction will weigh 24,860 tons. The total cost of the project is 935 million euros. EUR 325 million is financed by the EBRD alone . The steel structures were manufactured in Italy by Cimolai with steel from Salzgitter and pipes from Mannesmann Fuchs Rohr .
On April 29, 2015, it was announced at the G7 summit that the project would be completed in November 2017. In addition, they agreed to finance a further 530 million euros of the remaining 650 million euros.
In early October 2015, Novarka announced that over 20 million person- hours had been spent on the project. Workers from 27 nations have so far been involved in the construction.
From November 14, 2016, the new protective cover was moved towards the old sarcophagus at an average speed of 10 meters per hour. This made the new protective cover the largest mobile structure in the world. At the beginning of November, the general director of the nuclear power plant, Igor Gramotkin, stated in an open letter to several Ukrainian government members that the new protective cover should take its final position over the old sarcophagus on November 29, 2016.
After reaching the final position on schedule, the new protective cover was inaugurated on November 29, 2016.
Plastic membranes will be installed until commissioning, which will later ensure a tight connection between the new protective cover and the nuclear power plant. In addition, the cranes and all devices inside the protective cover are put into operation and tested. Approval procedures are running in parallel. On December 20, 2017, Spiegel reported online that the commissioning announced for 2017 would be delayed until the end of May 2018 due to the high radiation exposure.
On April 25, 2019, the European Bank for Reconstruction and Development (EBRD) announced the completion of a 72-hour test run of the protective cover. The official commissioning in the presence of the Ukrainian President Volodymyr Selenskyj took place on July 10, 2019.
Further construction projects
In addition to the protective cover, other buildings and facilities were or are being built that will enable the dismantling of the nuclear power plant after the completion of the NSC project.
Interim Spent Fuel Storage Facility
The "ISF2" facility is scheduled to start operations in 2018. In it, the more than 20,000 fuel elements from reactor blocks 1, 2 and 3 are to be processed, dried and crushed, which since October 2013 have completely filled an old wet storage facility. The processed fuel elements are then to be stored in metal drums in concrete modules on the site for at least 100 years. This facility is then to be dismantled.
Liquid Radioactive Waste Treatment Plant
The "LRTP" treatment facility has already been completed. In it, liquid radioactive waste, which was previously stored in tanks on the site, is to be converted into solid form so that it can also be stored in containers for a long time.
Web links
- SSE "Chernobyl NPP" - website of the nuclear power plant (English)
- SSE "Chernobyl NPP" - detailed reports on the progress (English)
- Oda Becker: 26 years after Chernobyl
- Time-lapse shot: NSC shift over the reactor on YouTube
- The sarcophagus - the new protective cover for Chernobyl. (No longer available online.) Formerly in the original ; accessed on May 11, 2019 . ( Page no longer available , search in web archives )
Individual evidence
- ↑ a b c d e Designing and Construction of a New Safe Confinement. Retrieved October 25, 2015 .
- ↑ a b c What happened in Chernobyl? Retrieved October 25, 2015 .
- ^ Society for Reactor Safety (ed.): Chernobyl ten years later. The accident and the safety of the RBMK systems, Cologne 1996, pp. 71–82. Online: https://www.grs.de/sites/default/files/pdf/GRS-121_Deut.pdf
- ↑ a b deutschlandfunk.de , Research News , March 20, 2015, Dagmar Röhrlich : Chernobyl and the new cover for the sarcophagus (accessed on: November 11, 2016)
- ↑ a b c The Chernobyl Shelter Implementation Plan. Retrieved October 25, 2015 .
- ^ A b Project "New Safe Confinement Construction". (No longer available online.) Archived from the original on June 14, 2015 ; accessed on October 25, 2015 . 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.
- ↑ The new sarcophagus - problem solved? Retrieved April 11, 2018 .
- ↑ Chernobyl's New Safe Confinement. Retrieved October 25, 2015 .
- ↑ Chernobyl: a site transformed. Retrieved October 25, 2015 .
- ↑ G7 says Chernobyl shelter to be completed by Nov 2017. Retrieved October 25, 2015 .
- ^ A Landmark Event of the NSC Project. Retrieved October 25, 2015 .
- ↑ Ten meters per hour. Retrieved November 15, 2016 .
- ↑ To Open Letter. Retrieved November 13, 2016 .
- ↑ New protective cover for nuclear ruins inaugurated. (No longer available online.) Archived from the original on November 29, 2016 ; accessed on November 29, 2016 . 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.
- ↑ Chernobyl - "The real challenge is yet to come". Retrieved December 1, 2016 .
- ↑ Christoph Seidler: Radiation too high: completion of the Chernobyl sarcophagus is delayed . In: Spiegel Online . December 20, 2017 ( spiegel.de [accessed December 20, 2017]).
- ↑ Chernobyl's New Safe Confinement project completes final commissioning test. April 25, 2019, accessed June 2, 2019 .
- ↑ mdr.de: Protective cover in Chernobyl officially in operation | MDR.DE. Retrieved August 12, 2019 .
- ↑ Launch of new confinement at Chornobyl NPP postponed until May 2018. Retrieved on March 10, 2018 .
- ↑ Deutschlandfunk , Wissenschaft im Brennpunkt , May 25, 2015, Dagmar Röhrlich : Cleaning up in troubled times (accessed on: November 11, 2016)
- ^ A b Decommissioning the Chernobyl Nuclear Power Plant. Retrieved October 25, 2015 .
