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. Nuclear decommissioning is the administrative and technical process whereby a nuclear facility such as a nuclear power plant (NPP), 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. The International Atomic Energy Agency defines three options for decommissioning: 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. 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. 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 (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.