asked the Secretary of State for the Environment how many curies of plutonium-241 have been discharged into the sea from the Windscale plant; how much of this has to date decayed to Americium 241; and what is the projected rise in Americium 241 in the most affected area over the next 50 years.
About 540,000 curies of plutonium-241 had been discharged from Windscale up to the end of 1981. Its decay has so far led to the formation of about 5,000 curies of Americium 241. By the year 2030 it is estimated that about 15,500 curies of Americium 241 will have been formed by the decay of Plutonium-241 discharged to the end of 1981. Plutonium and Americium remaining in the sea water will be rapidly dispersed, but some will remain in the area incorporated in the sediments.