Вывод из эксплуатации ядерных объектов

Process of dismantling a nuclear facility

Nuclear decommissioning is the process leading to the irreversible complete or partial closure of a nuclear facility, usually a nuclear reactor, with the ultimate aim at termination of the operating licence. The process usually runs according to a decommissioning plan, including the whole or partial dismantling and decontamination of the facility, ideally resulting in restoration of the environment up to greenfield status. The decommissioning plan is fulfilled when the approved end state of the facility has been reached. The process typically takes about 15 to 30 years, or many decades more when an interim safe storage period is applied for radioactive decay. Radioactive waste that remains after the decommissioning is either moved to an on site storage facility where it is still under control of the owner, or moved to a dry cask storage or disposal facility at another location. The final disposal of nuclear waste from past and future decommissioning is a growing still unsolved problem. Decommissioning is an administrative and technical process. The facility is dismantled to the point that it no longer requires measures for radiation protection. It includes clean up of radioactive materials. Once a facility is fully decommissioned, no radiological danger should persist. The license will be terminated and the site released from regulatory control. The plant licensee is then no longer responsible for the nuclear safety. The costs of decommissioning are to be covered by funds that are provided for in a decommissioning plan, which is part of the facility's initial authorization. They may be saved in a decommissioning fund, such as a trust fund. There are worldwide also hundreds of thousands small nuclear devices and facilities, for medical, industrial and research purposes, that will have to be decommissioned at some point.

Nuclear decommissioning is the administrative and technical process leading to the irreversible closure of a nuclear facility such as a nuclear power plant (NPP), a research reactor, an isotope production plant, a particle accelerator, or uranium mine. It refers to the administrative and technical actions taken to remove all or some of the regulatory controls from the facility to bring about that its site can be reused. Decommissioning includes planning, decontamination, dismantling and materials management. Decommissioning is the final step in the lifecycle of a nuclear installation. It involves activities from shutdown and removal of nuclear material to the environmental restoration of the site. The term decommissioning covers all measures carried out after a nuclear installation has been granted a decommissioning licence until nuclear regulatory supervision is no longer necessary. The aim is ideally to restore the natural initial state that existed before the construction of the nuclear power plant, the so called greenfield status. Decommissioning includes all steps as described in the decommissioning plan, leading to the release of a nuclear facility from regulatory control. The decommissioning plan is fulfilled when the approved end state of the facility has been reached. Disposal facilities for radioactive waste are closed rather than decommissioned. The use of the term decommissioning implies that no further use of the facility (or part thereof) for its existing purpose is foreseen. Though decommissioning typically includes dismantling of the facility, it is not necessarily part of it as far as existing structures are reused after decommissioning and decontamination.,p. 49 50

From the owner's perspective, the ultimate aim of decommissioning is termination of the operating license, once he has given certainty that the radiation at the site is below the legal limits, which in the US is an annual exposure of 25 millirem in case of releasing of the site to the public for unrestricted use. up to 50 years are for radioactive decay and 10 years to dismantle the facility.

Under supervision of the IAEA, a member state first developes a decommissioning plan to demonstrate the feasibility of decommissioning and assure that the associated costs are covered. At the final shutdown, a final decommissioning plan describes in detail how the decommissioning will take place, how the facility will be safely dismantled, ensuring radiation protection of the workers and the public, addressing environmental impacts, managing radioactive and non radioactive materials, and termination of the regulatory authorization. The problem of long term disposal of nuclear waste is still unsolved. Pending the availability of geologic repository sites for long term disposal, interim storage is necessary. As the planned Yucca Mountain nuclear waste repository – like elsewhere in the world – is controversial, on or off site storage in the US usually takes place in Independent Spent Fuel Storage Facilities (ISFSI's). In the UK, all eleven Magnox reactors are in decommissioning under responsibility of the NDA. The spent fuel was removed and transferred to the Sellafield site in Cumbria for reprocessing. Facilities for "temporary" storage of nuclear waste – mainly 'Intermediate Level Waste' (ILW) – are in the UK called Interim Storage Facilities (ISF's).

The decommission of a nuclear reactor can only take place after the appropriate licence has been granted pursuant to the relevant legislation. As part of the licensing procedure, various documents, reports and expert opinions have to be written and delivered to the competent authority, e. g. safety report, technical documents and an environmental impact assessment (EIA). In the European Union these documents are a precondition for granting such a licence is an opinion by the European Commission according to Article 37 of the Euratom Treaty. On the basis of these general data, the Commission must be in a position to assess the exposure of reference groups of the population in the nearest neighbouring states.

In France, decommissioning of Brennilis Nuclear Power Plant, a fairly small 70 MW power plant, already cost €480 million (20x the estimate costs) and is still pending after 20 years. Despite the huge investments in securing the dismantlement, radioactive elements such as plutonium, caesium 137 and cobalt 60 leaked out into the surrounding lake. In the UK, the decommissioning of civil nuclear assets were estimated to be £99 to £232 billion (2020), earlier in 2005 under estimated to be £20 40 billion. The Sellafield site (Calder Hall, Windscale and the reprocessing facility) alone accounts for most of the decommissioning cost and increase in cost;
as of 2015, the costs were estimated £53.2 billion. A 2013 estimate by the United Kingdom's Nuclear Decommissioning Authority predicted costs of at least £100 billion to decommission the 19 existing United Kingdom nuclear sites. In Germany, decommissioning of Niederaichbach nuclear power plant, a 100 MW power plant, amounted to more than €143 million. Lithuania has increased the prognosis of decommissioning costs from €2019 million in 2010 to €3376 million in 2015. Because the government has failed to establish a central repository, the federal government pays about half a billion dollars a year to the utilities as penalty, to compensate the cost of storage at more than 80 ISFSI sites in 35 states as of 2021. KPMG estimated the total cost of decommissioning the US nuclear fleet as of 2018 to be greater than US$150 billion. About two thirds can be attributed to costs for termination of the NRC operating licence; 25% to management of spent fuel; and 10% to site restoration.

Organizations that promote the international sharing of information, knowledge, and experiences related to nuclear decommissioning include the International Atomic Energy Agency, the Organization for Economic Co operation and Development's Nuclear Energy Agency and the European Atomic Energy Community. or $330 million. Marine power plants are generally smaller than land based electrical generating stations. The biggest American military nuclear facility for the production of weapons grade plutonium was Hanford site (in the State of Washington), now defueled, but in a slow and problematic process of decontamination, decommissioning, and demolition. There is "the canyon", a large structure for the chemical extraction of plutonium with the PUREX process. There are also many big containers and underground tanks with a solution of water, hydrocarbons and uranium plutonium neptunium cesium strontium (all highly radioactive). With all reactors now defueled, some were put in SAFSTOR (with their cooling towers demolished). Several reactors have been declared National Historic Landmarks.

Location Reactor type Operative life Decommissioning Decommissioning costs Connecticut Yankee Connecticut PWR 619 MWe 1968–1996 (28 years) 1998 2007 DECON; on site ISFSI waste storage 931 mln; Crystal River 3 Florida PWR 825 MWe 1977–2009 (32 years) 2013 2037 (estimated) DECON; on site ISFSI waste storage In 2013 estimated ~$1,2 bln Dresden Unit 1 (Illinois) BWR 207 MWe 1960–1978 (18 years) Defueled in safety in 1998 now in SAFSTOR Fuel in on site dry casks. Still unknown Fort St. Vrain (Colorado) HTGR (helium graphite) 330 MWe 1979–1989 (10 years) 1989 1992 (3 years) dismantled; off site ISFSI waste storage; replaced by conventional station $283 million Pacific Gas & Electric – Humboldt BayUnit 3 BWR 63 MWe 1963–1976(13 years) 1988 2021(33 years)License terminated in Oct 2021;site released for unrestricted use;New license for on site storage facility for the spent fuel. UnknownFund for $53.3 million required for decommissioning of storage alone.</small> $635 million Piqua NGS (Ohio) OCM (Organically Cooled/Moderated) reactor 46 MWe 2 years (closed in 1966) ENTOMB (coolant design inadequate for neutron flux) Still unknown Rancho Seco NGS (California) PWR 913 MWe 12 years (Closed after a referendum in 1989) SAFSTOR: 5–10 years completed in 2009
Fuel in insite long term dry cask storage $538.1 million San Onofre NGS Unit 1 (California) PWR 436 MWe Westinghouse Electric Corporation 1967–1992 (25 years) 1993 2032 (estimated) dismantled; on site ISFSI waste storage for whole plantStill unknown San Onofre NGS Units 2, 3 (California) PWR 1070 MWe 1080 MWe Unit 2: 1983–2013 Unit 3: 1984–2013
In 2011, Edison finished replacing the steam generators in both reactors with improved Mitsubishi ones, but the new design had several problems, cracked, causing leaks and vibrations. in defueling. Permanent shutdown – DECON soon defuelingStill unknown
2014 cost forecast: $3.926 billion to $4.4 billion Shippingport (Pennsylvania) BWR 60 MWe 25 years (closed in 1989) Decon completed dismantled in 5 years (first small experimental reactor) $98.4 million Three Mile Island Nuclear Generating Station Unit 2 (Pennsylvania) PWR 913 MWe 1978–1979 Core meltdown incident Post Defuelling Phase 2 (1979) $805 million (estimated) Trojan (Oregon) PWR 1,180 MWe 16 years (Closed in 1993 because of proximity to seismic fault) SAFSTOR (cooling tower demolished in 2006) Vermont Yankee BWR 620 MWe (General Electric) 1972–2014 (42 years) Ongoing 2015– ~$1.24 billion Yankee Rowe (Massachusetts) PWR 180 MWe 1961–1991 (30 years) Construction cost was $45 million completed in 2007 on site ISFSI waste storage $608 million (See main article) Zion Units 1, 2 (Illinois) 2 x PWR 1040 MWe (Westinghouse) 1973/1974–1998 (25 years) 1998 2020 after SAFSTOR full dismantling; New on site for spent fuel storage Costs for SAFSTOR unknown; for dismantling & decontamination estimated in 2010 $1 billion + demolition city fees millions; for remaining waste unknown