§ Mr. William Rossasked the Secretary of State for the Environment at the present level of activity, what is the estimated total number of curies of plutonium 241 expected to be discharged to the sea from the Windscale plant by the year 2031; of that total how much would by then have decayed to americium 241.
§ Mr. Buchanan-SmithI have been asked to reply.
In view of the continuing developments in waste treatment technology, it would be unrealistic to give an estimate of how much plutonium 241 might be discharged to sea from the Sellafield—formerly Windscale—works by 2031.
§ Mr. William Rossasked the Secretary of State for the Environment, further to the answer of 26 April 1982, 522W Official Report, c. 1982, how many curies of plutonium 241 have now been discharged into the sea from the Windscale plant; how much decayed into americium 241 by the end of 1982; how much remained as plutonium 241; how much of the plutonium 241 and the americium 241 discharged to the end of 1982 is expected to remain in the sea bottom sediment in 50 years' time; and whether any of those sediments are expected by that time to be either ashore, or above water level at any state of the tide.
§ Mr. Peter WalkerAbout 550,000 curies of plutonium have been discharged into the sea from the Sellafield—formerly Windscale—plant. It is estimated that about one third of this had decayed to give some 5,560 curies of americium 241 by the end of 1982, the rest remaining as plutonium 241. Practically all the plutonium 241 and americium 241 remains indefinitely immobilised below the surface layer of seabed sediments.