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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 Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...
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.Benjamin K. Sovacool. "A Critical Evaluation of Nuclear Power and Renewable Electricity in Asia", ''
Journal of Contemporary Asia The ''Journal of Contemporary Asia'' is a peer-reviewed academic journal covering Asian studies. It was established in 1970 and is published 5 times a year by Routledge. The editor-in-chief is Kevin Hewison (University of North Carolina at Chapel H ...
'', Vol. 40, No. 3, August 2010, p. 373.
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 Greenfield or Greenfields may refer to: Engineering and Business * Greenfield agreement, an employment agreement for a new organisation * Greenfield investment, the investment in a structure in an area where no previous facilities exist * Greenf ...
" status.


Definition

Nuclear decommissioning is the administrative and technical process whereby a nuclear facility such as a
nuclear power plant A nuclear power plant (NPP) is a thermal power station in which the heat source is a nuclear reactor. As is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a generator that produces ...
(NPP), a research reactor, an
isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( mass num ...
production plant, a particle accelerator, or
uranium mine Uranium mining is the process of extraction of uranium ore from the ground. Over 50 thousand tons of uranium were produced in 2019. Kazakhstan, Canada, and Australia were the top three uranium producers, respectively, and together account ...
is dismantled to the point that it no longer requires measures for
radiation protection Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Expos ...
. The progressive demolition of buildings and removal of
radioactive Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consi ...
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 Greenfield status (also known as "unrestricted re-use") is an end point wherein a parcel of land that had been in industrial use is, in principle, restored to the conditions existing before the construction of the plant. All power plants, coal, ga ...
". 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'' (Early Site Release/
Decon Decon'' is a New York-based creative studio that houses production, creative, strategy, and music divisions. The company creates campaigns on behalf of brands and advertising agencies. History Originally named Deconstruction Company, the comp ...
in the United States) allows for the facility to be removed from regulatory control relatively soon after shutdown. Final dismantling or
decontamination Decontamination (sometimes abbreviated as decon, dcon, or decontam) is the process of removing contaminants on an object or area, including chemicals, micro-organisms or radioactive substances. This may be achieved by chemical reaction, disinfecti ...
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'' (or Safestor(e)
Safstor SAFSTOR is a nuclear decommissioning method in which a nuclear power plant or facility governed by the United States Nuclear Regulatory Commission, is ''"placed and maintained in a condition that allows the facility to be safely stored and subsequ ...
) 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

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 study (EIS). In the European Union these documents are the basis for the environmental impact assessment (EIA) 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 The Euratom Treaty, officially the Treaty establishing the European Atomic Energy Community, established the European Atomic Energy Community. It was signed on 25 March 1957 at the same time as the Treaty establishing the European Economic Com ...
. 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 The Brennilis Nuclear Power Plant (EL-4) is a decommissioned site located in the Monts d'Arrée in the commune of Brennilis in Finistère, France. History The Commissariat à l'énergie atomique began construction of this experimental react ...
, 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 Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exh ...
, caesium-137 and
cobalt-60 Cobalt-60 (60Co) is a synthetic radioactive isotope of cobalt with a half-life of 5.2713 years. It is produced artificially in nuclear reactors. Deliberate industrial production depends on neutron activation of bulk samples of the monoisot ...
leaked out into the surrounding lake. In the UK, decommissioning of the Windscale Advanced gas cooled reactor (WAGR), 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 Niederaichbach is a municipality in the district of Landshut Landshut (; bar, Landshuad) is a town in Bavaria in the south-east of Germany. Situated on the banks of the River Isar, Landshut is the capital of Lower Bavaria, one of the seve ...
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 (ISD), 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 en, Viennese , iso_code = AT-9 , registration_plate = W , postal_code_type = Postal code , postal_code = , timezone = CET , utc_offset = +1 , timezone_DST ...
, 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 Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exh ...
, research fuel facilities, nuclear reprocessing chemical separation facilities, etc. The total cost to decommission the nuclear fission industry in the
World In its most general sense, the term "world" refers to the totality of entities, to the whole of reality or to everything that is. The nature of the world has been conceptualized differently in different fields. Some conceptions see the worl ...
(from 2001 to 2050) was estimated at around US$1
trillion ''Trillion'' is a number with two distinct definitions: *1,000,000,000,000, i.e. one million million, or (ten to the twelfth power), as defined on the short scale. This is now the meaning in both American and British English. * 1,000,000,000,00 ...
.


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 The European Commission (EC) is the executive of the European Union (EU). It operates as a cabinet government, with 27 members of the Commission (informally known as "Commissioners") headed by a President. It includes an administrative body ...
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 France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
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 The Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operat ...
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 The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United States ...
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 (cold shut-down, defueling, SAFSTOR, internal demolition), but only 17 have been taken to fully "
greenfield status Greenfield status (also known as "unrestricted re-use") is an end point wherein a parcel of land that had been in industrial use is, in principle, restored to the conditions existing before the construction of the plant. All power plants, coal, ga ...
". 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 In the controlled demolition industry, building implosion is the strategic placing of explosive material and timing of its detonation so that a structure collapses on itself in a matter of seconds, minimizing the physical damage to its immedia ...
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 (specially with high
neutron The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the atomic nucleus, nuclei of atoms. Since protons and ...
-flux), 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. As of 2020, the average age of these reactors was about 39 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.


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 (in the
State of Washington Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the 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 Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exh ...
with the
PUREX PUREX (plutonium uranium reduction extraction) is a chemical method used to purify fuel for nuclear reactors or nuclear weapons. PUREX is the '' de facto'' standard aqueous nuclear reprocessing method for the recovery of uranium and pluto ...
process. There are also many big containers and underground tanks with a solution of water, hydrocarbons and
uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
-
plutonium Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exh ...
- neptunium- cesium- strontium (all highly radioactive). With all reactors now defueled, some were put in
SAFSTOR SAFSTOR is a nuclear decommissioning method in which a nuclear power plant or facility governed by the United States Nuclear Regulatory Commission, is ''"placed and maintained in a condition that allows the facility to be safely stored and subsequ ...
(with their cooling towers demolished). Several reactors have been declared
National Historic Landmark A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places liste ...
s.


See also

* Lists of nuclear disasters and radioactive incidents * Marcoule Nuclear Site in France * Nuclear Decommissioning Authority *
Nuclear entombment Nuclear entombment (also referred to as "safe enclosure") is a method of nuclear decommissioning in which radioactive contaminants are encased in a structurally long-lived material, such as concrete. This prevents radioactive material and other c ...
* Ship-Submarine Recycling Program


References


External links

*
NUCLEAR ENERGY AGENCY of the Organisation for Economic Co-operation & DevelopmentCost of Decommissioning Nuclear Energy Plants
(2016)
UNITED STATES NUCLEAR REGULATORY COMMISSION

Business Insider – UKGetting Rid Of Old Nuclear Reactors Worldwide Is Going To Cost Way More Than People Think

Germany's economy minister Sigmar Gabriel says state won't pay for nuclear decommissioning
(May 18, 2014)
Nuclear Decommissioning Report (www.ndreport.com) is the multi-media platform for the nuclear decommissioning industry.

decommissioning.info is a portal with information on nuclear decommissioning



European website on decommissioning of nuclear installations


rapport by the German Wuppertal Institute, commissioned by the
European Commission The European Commission (EC) is the executive of the European Union (EU). It operates as a cabinet government, with 27 members of the Commission (informally known as "Commissioners") headed by a President. It includes an administrative body ...
. May 2007.
Master 'Nuclear Energy' – Decommissioning and Waste management
{{DEFAULTSORT:Nuclear Decommissioning Nuclear technology Nuclear power stations Radioactive waste Nuclear liability Radioactive contamination