Dr. ThomasTo ask the Secretary of State for the Environment what has been(a) the average level and (b) the greatest reported level of worker exposure to radioactivity at the B-30 pond at Sellafield; and whether the worker exposure levels have ever exceeded legal limits.
§ Mr. Michael SpicerI have been asked to reply.
I am informed that average annual external doses to the most exposed group of B30 workers have reduced from 28.3 millisieverts in 1984 to 18.5 millisieverts in 1988. Following the introducton of the Ionising Radiation Regulations in 1986, internal doses have also been assessed. The addition of internal doses in 1988 had the effect of adding 2.5 millisieverts, to give a total average whole body dose of 21 millisieverts in that year.
I have asked the chairman of BNFL to write to the hon. Member on the question of average doses prior to 1984.
Since 1971, the annual statutory limit of 50 millisieverts external dose has been exceeded by two B30 personnel in 1978; one in 1980; and two in 1985. The highest dose received was an annual dose of 86.1 millisieverts in 1980.