§ Dr. Roger Thomasasked the Secretary of State for Energy (1) if he will describe what plans there are for the decommissioning of Magnox power stations;
(2) if he will estimate the total radioactivity of the structural materials when the Magnox nuclear power stations reach the end of their useful life; and how this compares with the radioactivity released by the Hiroshima bomb.
§ Mr. Norman LamontI am advised by the CEGB that there are no immediate plans for shutting down and dismantling any of the reactors at the CEGB's Magnox stations. The board's current policy is to operate these stations for as long as possible consistent with their safety and economic viability.
It is expected that the first stage of decommissioning, the removal of fuel which contains most of the radioactivity, will be completed in the first few years following shutdown. The second stage, reduction to minimum size outside the 141W biological shield, might then be completed within a decade of shutdown. Dismantling and disposal of the reactor structures may be delayed for a further period to allow their activity to decay to a low level. Decisions on these matters will be taken in the light of the circumstances prevailing at each station, bearing in mind safety costs, environmental aspects and the possible need to reuse the site.
Information on the radioactivity of the structural materials at the end of the Magnox stations' useful-lives is not readily available but it is estimated by the CEGB that after completion of the first two stages of decommissioning referred to above, i.e. about 10 years after reactor shutdown, the structure of a typical single core Magnox reactor would contain approximately 100,000 curies of radioactivity. A direct comparison with the Hiroshima bomb is inappropriate since the radioactivity is contained in power station structural materials which could not explode.
Power stations in Scotland are the responsibility of my right hon. Friend the Secretary of State for Scotland.