§ Mr. Michael McNair-Wilson
asked the Secretary of State for Defence how recently sites within 10 to 15 miles radius of the Atomic Weapons Research Establishment Aldermaston and Royal ordnance factory Burghfield have been monitored for radioactivity; what environmental discharges have been collected and checked; and what was the most recent recommendation of the International Commission on Radiological Protection about a radioactivity level.
§ Mr. Lee
Environmental surveys are carried out on a continuing and routine basis around the Atomic Weapons Research Establishmnt, Aldermaston, and the Royal ordnance factory, Burghfield, in the area up to some 10 to 15 miles from the sites. These include monitoring at fortnightly, monthly and quarterly intervals, depending on the type of monitoring. The last fortnightly cycle was completed during the week commencing 9 December; the last monthly cycle at the end of November; and the last quarterly cycle at the end of September. All three cycles will have been completed again by the end of the year. Monitoring covers both airborne and liquid discharges, the former on a continuous basis, the latter prior to each batch being released.
The International Commission on Radiological Protection made its last major recommendations in 1977 and has made minor changes as necessary at roughly annual intervals since then. The commission makes recommendations on radiological doses to people, including both classified radiation workers and members of the general public, rather than on levels of radioactivity in waste discharges.
The principal recommendation for members of the public is that it would be prudent to limit exposure on the basis of a lifetime average annual dose of 1 millisievert. Our aim is that the levels of radioactivity in waste discharges from AWRE and ROF Burghfield are such that they could lead to a radiological dose no greater than one thousandth of this figure. In practice, this aim is usually achieved by a substantial margin.