Factors to be considered in selecting a decommissioning strategy

The introduction outlines the scope of the work that will be carried out during three stages (which are defined) of decommissioning a nuclear power station noting that the content of each stage may vary somewhat for reactor system and country in particular whether defuelling forms an integral part of Stage 1. Some important factors to be taken into account are the nature and quantities of contaminated and neutron activated materials and the techniques required to dismantle the plant and manage the waste. Timescales for carrying out each stage are discussed in relation to water and gas cooled reactor systems noting the benefits of delay in terms of radiological protection during decommissioning and limiting effects of the long lived radioactive isotopes. Various courses of action are discussed. It is concluded that following final or definitive shutdown the reactors will be defuelled as soon as reasonably practicable. A decision to proceed to Stages 2 or 3 depends on safety, technical, economic, national policy and public opinion. (author)