Nuclear decommissioning
Nuclear decommissioning is the process whereby a nuclear facility is dismantled to the point that it no longer requires measures for radiation protection.
The presence of radioactive material necessitates processes that are potentially occupationally hazardous, expensive, time-intensive, and present environmental risks that must be addressed to ensure radioactive materials are either transported elsewhere for storage or stored on-site in a safe manner.
The challenge in nuclear decommissioning is not just technical, but also economical and social.
Decommissioning is an administrative and technical process.
It includes clean-up of radioactive materials and progressive demolition of the facility.
Once a facility is fully decommissioned, no radiological danger should persist.
The costs of decommissioning are generally spread over the lifetime of a facility and saved in a decommissioning fund.
After a facility has been completely decommissioned, it is released from regulatory control and the plant licensee is no longer responsible for its nuclear safety.
Decommissioning may proceed all the way to "greenfield" status.
Definition
Nuclear decommissioning is the administrative and technical process whereby a nuclear facility such as a nuclear power plant, a research reactor, an isotope production plant, a particle accelerator, or uranium mine is dismantled to the point that it no longer requires measures for radiation protection.The progressive demolition of buildings and removal of radioactive material is potentially occupationally hazardous, expensive, time-intensive, and presents environmental risks that must be addressed to ensure radioactive materials are either transported elsewhere for storage or stored on-site in a safe manner. Decommissioning may proceed all the way to "greenfield status". Once a facility is decommissioned no radioactive danger persists and it can be released from regulatory control.
Options
The International Atomic Energy Agency defines three options for decommissioning:- Immediate Dismantling allows for the facility to be removed from regulatory control relatively soon after shutdown. Final dismantling or decontamination activities begin within a few months or years, and depending on the facility, it could take five years or more. After being removed from regulatory control, the site becomes available for unrestricted use.
- Safe Enclosure postpones the final decommissioning for a longer period, usually 40 to 60 years. The nuclear facility is placed into a safe storage configuration during this time.
- Entombment/Entomb involves placing the facility in a condition that allows the remaining radioactive material to remain on-site indefinitely. The size of the area where the radioactive material is located is generally minimized and the facility is encased in a long-lived material such as concrete, with the aim of preventing a release of radioactive material.
Legal aspects
In the European Union these documents are the basis for the environmental impact assessment according to Council Directive 85/337/EEC. A precondition for granting such a licence is an opinion by the European Commission according to Article 37 of the Euratom Treaty. Article 37 obliges every Member State of the European Union to communicate certain data relating to the release of radioactive substances to the Commission. This information must reveal whether and if so what radiological impacts decommissioning – planned disposal and accidental release – will have on the environment, i.e. water, soil or airspace, of the EU Member States. 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.
Cost
In the United States, the NRC recommends that the costs of decommissioning should be spread over the lifetime of a facility and saved in a decommissioning fund. Repository delay seems to be effective in reducing NPP decommissioning costs.In France, decommissioning of Brennilis Nuclear Power Plant, a fairly small 70 MW power plant, already cost €480 million 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, decommissioning of the Windscale Advanced gas cooled reactor, a 32 MW prototype power plant, cost €117 million.
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.
New methods for decommissioning have been developed in order to minimize the usual high decommissioning costs.
One of these methods is in situ decommissioning, meaning that the reactor is entombed instead of dismantled.
This method was implemented at the U.S. Department of Energy Savannah River Site in South Carolina for the closures of the P and R Reactors.
With this tactic, the cost of decommissioning both reactors was $73 million.
In comparison, the decommissioning of each reactor using traditional methods would have been an estimated $250 million.
This results in a 71% decrease in cost by using ISD.
In 2004, in a meeting in Vienna, the International Atomic Energy Agency estimated the total cost for the decommissioning of all nuclear facilities.
Decommissioning of all nuclear power reactors in the world would require US$187 billion; US$71 billion for fuel cycle facilities; less than US$7 billion for all research reactors; and US$640 billion for dismantling all military reactors for the production of weapons-grade plutonium, research fuel facilities, nuclear reprocessing chemical separation facilities, etc.
The total cost to decommission the nuclear fission industry in the World was estimated at around US$1 trillion.
Decommissioning funds
In Europe there is considerable concern over the funds necessary to finance final decommissioning. In many countries either the funds do not appear sufficient to cover decommissioning and in other countries decommissioning funds are used for other activities, putting decommissioning at risk, and distorting competition with parties who do not have such funds available.In 2016 the European Commission assessed that European Union's nuclear decommissioning liabilities were seriously underfunded by about 118 billion euros, with only 150 billion euros of earmarked assets to cover 268 billion euros of expected decommissioning costs covering both dismantling of nuclear plants and storage of radioactive parts and waste. France had the largest shortfall with only 23 billion euros of earmarked assets to cover 74 billion euros of expected costs.
Similar concerns exist in the United States, where the U.S. Nuclear Regulatory Commission has located apparent decommissioning funding assurance shortfalls and requested 18 power plants to address that issue. The decommissioning cost of Small modular reactors is expected to be twice as much respect to Large Reactors.
International collaboration
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. In addition, an online system called the Deactivation and Decommissioning Knowledge Management Information Tool was developed under the United States Department of Energy and made available to the international community to support the exchange of ideas and information. The goals of international collaboration in nuclear decommissioning are to reduce decommissioning costs and improve worker safety.List of inactive or decommissioned civil nuclear reactors
A wide range of nuclear facilities have been decommissioned so far. The number of decommissioned nuclear reactors out of the List of nuclear reactors is small. As of 2016, 150 nuclear reactors were shut-off, in several early and intermediate stages, but only 17 have been taken to fully "greenfield status". Some of these sites still host spent nuclear fuel in the form of dry casks embedded in concrete filled steel drums.Several nuclear engineering and building demolition companies specialize in nuclear decommissioning, which has become a profitable business. More recently, construction and demolition companies in the UK have also begun to develop nuclear decommissioning services. Due to the radioactivity in the reactor structure, decommissioning takes place in stages. Plans for decommissioning reactors have a time frame of decades. The long time frame makes reliable cost estimates difficult and cost overruns are common even for "quick" projects.
As of 2017, most nuclear plants operating in the United States were designed for a life of about 30–40 years and are licensed to operate for 40 years by the US Nuclear Regulatory Commission. The average age of these reactors is 32 years. Many plants are coming to the end of their licensing period and if their licenses are not renewed, they must go through a decontamination and decommissioning process.
| Country | Location | Reactor type | Operative life | Decommissioning phase | Dismantling costs |
| Austria | Zwentendorf | BWR 723 MWe | Never activated due to referendum in 1978 | Now a technics museum | |
| Belgium | SCK•CEN – BR3, located at Mol, Belgium | PWR | 25 years | Decon completed European pilot project | |
| Bulgaria | Kozloduy Units 1, 2, 3, 4 | PWR VVER-440 | Reactors 1,2 closed in 2003, reactors 3,4 closed in 2006 | De-fuelling | |
| Canada | Gentilly Unit 1 | CANDU-BWR 250 MWe | 180 days | "Static state" since 1986 | stage two: $25 million |
| Canada | Pickering NGS Units A2, A3 | CANDU-PWR 8 x 542 MWe | 30 years | Two units currently in "cold standby" Decommissioning to begin in 2020 | calculated: $270–430/kWe |
| China | Beijing | HWWR 10 MWe | 49 years | SAFSTOR until 2027 | proposed: $6 million for dismantling $5 million for fuel remotion |
| France | Brennilis | :fr:HWGCR|HWGCR 70 MWe | 12 years | Phase 3 | already spent €480 million |
| France | Bugey Unit 1 | UNGG Gas cooled, graphite moderator | 1972–1994 | postponed | |
| France | Chinon Units 1, 2, 3 | Gas-graphite | postponed | ||
| France | Chooz-A | PWR 300 MW | 24 years | Fully decommissioned – Greenfield | |
| France | Saint-Laurent | Gas-graphite | 1969–1992 | Postponed | |
| France | Rapsodie at Cadarache | Experimental Fast breeder nuclear reactor 40 MWe | 15 years | 1983: Defuelling 1987: Remotion of neutron reflectors 1985–1989: Decontamination of sodium coolant Accident when cleaning residual sodium in vessel with ethyl carbitol | The removed activity is estimated to around 4800 TBq. 600 TBq in 1990 still contained in 1ry vessel The dose burden from 1987 to 1994 was 224 mSv. RAPSODIE reached IAEA level 2 of decomm in 2005 STAGE 3 is planned in 2020 |
| France | Phénix at Marcoule | Experimental Fast breeder nuclear reactor 233 MWe | 36 years Defuelled | estimated for the future: $4000/kWe | |
| France | Superphénix at Creys-Malville | Fast breeder nuclear reactor | 11 years Defuelled 2) Extraction of Sodium Pipe cutting with a robot | estimated for the future: $4000/kWe | |
| East Germany | Greifswald Units 1, 2, 3, 4, 5, 6 | VVER-440 5 x 408 MWe | Reactors 1–5 closed in 1989/1990, reactor 6: finished but never operated | Immediate dismantling | ~ $330/kWe |
| East Germany | Rheinsberg Unit 1 | VVER-210 70–80 MWe | 24 years | In dismantling since 1996 Safstor | ~ $330/kWe |
| East Germany | Stendal Units 1, 2, 3, 4 | VVER-1000 | Never activated | Not radioactive | |
| West Germany | Gundremmingen-A | BWR 250 MWe | 11 years | Immediate dismantling pilot project | |
| India | Rajasthan Atomic Power Station Unit 1 | PHWR 100 MWe | 44 years | ||
| Iraq | Osiraq/Tammuz Unit 1 | BWR 40 MWe Nuclear reactor with weapons-grade plutonium production capability | Not radioactive: never supplied with uranium | ||
| Italy | Caorso | BWR 840 MWe | 3 years | SAFSTOR: 30 years | €450 million + €300 million |
| Italy | Garigliano | BWR 150 MWe | Closed on March 1, 1982 | SAFSTOR: 30 years | |
| Italy | Latina | Magnox 210 MWe Gas-graphite | 24 years | SAFSTOR: 30 years | |
| Italy | Trino Vercellese | PWR Westinghouse, 270 MWe | SAFSTOR: 30 years | ||
| Japan | Fukushima Dai-ichi Unit 1 | BWR 439 MWe | November 17, 1970 - March 11, 2011 | Since 2011 Tōhoku earthquake and tsunami of March 11 Hydrogen explosion | Estimated at ¥10 trillion for decontaminating Fukushima and dismantling all reactors in Japan and considering long time damage to environment and economy, including agriculture, cattle breeding, fishery, water potabilization, tourism, loss of reputation in the world . |
| Japan | Fukushima Dai-ichi Unit 2 | BWR 760 MWe | December 24, 1973 - March 11, 2011 | ||
| Japan | Fukushima Dai-ichi Unit 3 | BWR 760 MWe | October 26, 1974 - March 11, 2011 | ||
| Japan | Fukushima Dai-ichi Unit 4 | BWR 760 MWe | February 24, 1978 - March 11, 2011 | Since March 11, 2011 Reactor defueled when tsunami hit Damage to spent fuel cooling-pool | |
| Japan | Fukushima Dai-ichi Unit 5 | BWR 760 MWe | September 22, 1977 - March 11, 2011 | Planned decommissioning Cold shutdown since March 11, 2011 | |
| Japan | Fukushima Dai-ichi Unit 6 | BWR 1067 MWe | May 4, 1979 - March 11, 2011 | Planned decommissioning Cold shutdown since March 11, 2011 | |
| Japan | Fukushima Daini Unit 1 | BWR 1067 MWe | July 31, 1981 - 11 March 2011 | Planned decommissioning Cold shutdown since March 11, 2011 | |
| Japan | Fugen | Advanced thermal reactor 165 MWe | 1979 – 2003 | Cold shutdown | |
| Japan | Tokai Unit 1 | Magnox 160 MWe | 1966 – 1998 | Safstore: 10 years then decon until 2018 | ¥93 billion |
| North Korea | Yongbyon | Magnox-type | 20 years Deactivated after a treaty | SAFSTOR: cooling tower dismantled | |
| Netherlands | Dodewaard | BWR Westinghouse 58 MWe | 28 years | Defuelling completed SAFSTOR: 40 years | |
| Russia | Mayak | PUREX plant for uranium enrichment | Several severe incidents | ||
| Russia | Seversk | Three plutonium reactors Plant for uranium enrichment | Two fast-breeder reactors closed, after disarmaments agreements with USA in 2003. | ||
| Slovakia | Jaslovské Bohunice Units 1, 2 | VVER 440/230 2 X 440 MWe | | ||
| Spain | José Cabrera | PWR 1 x 160 MWe | 38 years | Defueled Dismantling Objective: green field in 2018 | 217.8 million |
| Spain | Santa María de Garoña | BWR/3 1 x 466 MWe | 1966 - 2013 | Defueled . Asked for renewal of license that was denied energy-politically from the government. Is in decommissioning state | |
| Spain | Vandellós Unit 1 | UNGG 480 MWe | 18 years Incident: fire in a turbogenerator | SAFSTOR: 30 years | Phases 1 and 2: €93 million |
| Sweden | Barsebäck Units 1, 2 | BWR 2 x 615 MW | Reactor 1: 24 years 1975 – 1999 Reactor 2: 28 years 1977 – 2005 | SAFSTOR: demolition will begin in 2020 | The Swedish Radiation Safety Authority has assessed that the costs for decommissioning and final disposal for the Swedish nuclear power industry may be underestimated by SKB by at least 11 billion Swedish crowns |
| Switzerland | DIORIT | MWe CO2-Gas-heavy water | Decommissioned | ||
| Switzerland | LUCENS | 8,3 MWe CO22-Gas-heavy water | Incident: fire in 1969 | Decommissioned | |
| Switzerland | SAPHIR | 0,01–0,1 MWe | 39 years | Decommissioned | |
| Ukraine | Chernobyl-4 | RBMK-1000 1000 MWe | hydrogen explosion, then graphite fire | ENTOMBMENT | Past: ? Future: riding sarcophagus in steel |
| United Kingdom | Berkeley | Magnox | 27 years | SAFSTOR: 30 years | around $2600/kWe |
| United Kingdom | Bradwell | Magnox 2 x 121 MWe | 1962–2002 | SAFSTOR: 30 years | around $2600/kWe |
| United Kingdom | Dounreay: DMTR | Fast-neutron reactor | 1958 - 1969 | Demolition conract awarded December 2018 | |
| United Kingdom | Dounreay: DFR | Loop-type fast breeder. 14 MWe. | 1959 - 1977 | Defueling | |
| United Kingdom | Dounreay: PFR | Pool-type fast breeder cooled by liquid sodium, fueled with MOX.250 MWe. | 1974 – 1994 Delays and reliability problems before reaching full power. | Remotely operated robot 'Reactorsaurus' will be sent in to decontaminate equipment as too dangerous a task for a human. Control panel has been earmarked for an exhibition at London Science Museum. | |
| United Kingdom | Sellafield-Calderhall | Magnox 4 x 60 MWe first nuclear power station. | August 27, 1956 – March 31, 2003 The first reactor had been in use for 47 years. | SAFSTOR: 30 years . | around $2600/kWe |
| United Kingdom | Chapelcross | Magnox 4 x 60 MWe | 1959 – 2004 | SAFSTOR: 30 years | around $2600/kWe |
| United Kingdom | Winfrith-Dorset Research area of the UKAEA | SGHWR 100 MWe | Operated from 1958 to 1990. | All nine reactors mostly dismantled | |
| United States | Crystal River 3 | PWR 860 MWe | 33 years Plant scheduled to restart in April 2011, but the project encountered a number of delays. After repairs, additional delamination began to occur in adjacent bays. Duke Energy announced in Feb-2013 that the Crystal River NPP would be permanently shut down. | From 2015 to 2019 in defueling. expected SAFSTOR 2019–2067 Decommissioning Periods ; Duration Period 1: Planning and Preparations 2.08 y. P. 2a: Dormancy w/Wet Fuel Storage 4.12 y. 2b: Dormancy w/Dry Fuel Storage 17.39 y. 2c: Dormancy w/No Fuel Storage 30.39 y. P. 3a: Site Reactivation & D. Prep 1.50 y. P. 4a: Large Component Removal 1.45 y. 4b & 4c: Systems Removal & Building Remediation 2 y. Period 4f: License Termination 0.75y. Period 5b: Site Restoration 1.50 y. | ~$1,2 billion |
| United States | Dresden Unit 1 | BWR 207 MWe | 18 years | Defueled in safety in 1998 now in SAFSTOR Fuel in on-site dry-casks. | |
| United States | Fort St. Vrain GS | HTGR 380 MWe | 12 years | Immediate Decon | $195 million |
| United States | Rancho Seco NGS | PWR 913 MWe | 12 years | SAFSTOR: 5–10 years completed in 2009 Fuel in insite long-term dry-cask storage | $538.1 million |
| United States | Three Mile Island Unit 2 | PWR 913 MWe | 1978-1979 Core fusion incident | Post-Defuelling Phase 2 | $805 million |
| United States | Shippingport | BWR 60 MWe | 25 years | Decon completed dismantled in 5 years | $98.4 million |
| United States | San Onofre NGS Unit 1 | PWR 436 MWe Westinghouse Electric Corporation | 25 years | Reactor dismantled and used as a storage site for spent fuel. | |
| United States | San Onofre NGS Units 2, 3 | 2 x PWR 1,075 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. | Permanent shutdown – DECON soon defueling | 2014 cost forecast: $3.926 billion to $4.4 billion |
| United States | Piqua NGS | OCM reactor 46 MWe | 2 years | ENTOMB | |
| United States | Trojan | PWR 1,180 MWe | 16 years | SAFSTOR | |
| United States | Yankee Rowe | PWR 185 MW | 31 years | Decon completed – Demolished | $608 million with $8 million per year upkeep |
| United States | Maine Yankee | PWR 860 MWe | 24 years | Decon completed – Demolished in 2004 | $635 million |
| United States | Vermont Yankee | BWR 620 MWe | 42 years | Defueling | ~$1.24 billion |
| United States | Exelon – Zion Units 1, 2 | 2 x PWR 1040 MWe | 25 years | SAFSTOR-EnergySolutions | $900–1,100 million |
| United States | Pacific Gas & Electric – Humboldt Bay Unit 3 | BWR 63 MWe | 13 years | On July 2, 1976, Humboldt Bay Power Plant Unit 3 was shut down for annual refueling and to conduct seismic modifications. In 1983, updated economic analyses indicated that restarting Unit 3 would probably not be cost-effective, and in June 1983, PG&E announced its intention to decommission the unit. On July 16, 1985, the U.S. Nuclear Regulatory Commission issued Amendment No. 19 to the HBPP Unit 3 Operating License to change the status to possess-but-not-operate, and the plant was placed into a SAFSTOR status. | Unknown – Closure date: December 31, 2015 |
Decommissioning of ships, mobile reactors, and military reactors
Many warships and a few civil ships have used nuclear reactors for propulsion. Former Soviet and American warships have been taken out of service and their power plants removed or scuttled. Dismantling of Russian submarines and ships and American submarines and ships is ongoing. 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, 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. With all reactors now defueled, some were put in SAFSTOR. Several reactors have been declared National Historic Landmarks.