Radioactive Waste (Hansard, 30 July 1997)

§ Mr. Rooker

My Department and others concerned with the disposal of radioactive waste have undertaken detailed searches of archive records relating to dumping at sea at Beaufort's dyke and elsewhere. Details of the searches carried out so far and the findings of each Department have been placed in the Library of the House.

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Information was found of two further instances of radioactive waste being dumped, or possibly being dumped, in Beaufort's dyke in addition to that reported to the House on 1 July, Official Report, columns 1586–60. The first instance was identified by the Scottish Office from a reference on one paper and relates to a disposal being arranged in 1957 at Cairn Ryan, a port used for the disposal of munitions to Beaufort's dyke, of a damaged closed caesium 137 source. There is no indication of the disposal site or any other information on the form of disposal. The level of radioactivity is described as about one quarter curie.

The second instance was identified by my Department concerning the dumping in 1976 of about 10,000 tonnes of building rubble and soil from the demolition of the premises of Thorium Ltd., a company that extracted thorium from minerals and left a waste product containing enhanced levels of naturally radioactive material. The authorisation required that the average radioactivity of this demolition material should be less than 10^-4 microcuries/gm and was not to exceed 5 x 10^-3 microcuries/gm in any part.

In respect of other locations not previously recognised as dump sites for radioactive waste, the Scottish Office has identified the following information: scrap from a Ferranti radioactive valve manufacturing unit was dumped by Ferranti between 1954 and 1957 in the Firth of Forth off North Queensferry. An estimate at the time put this at 7.5 mg of radium bromide at six-monthly intervals; advice to UK Time Ltd. in 1949 to dispose of 35,000 luminised dials likely to have contained in total between 25 and 50mg radium either on land or in sealed drums at least 5 miles off shore. A subsequent paper suggests that such dumping continued in the North sea during the 1950s; the dumping by ICI Ltd. of two anti-static devices—strontium 90—at the explosives disposal site off the Isle of Arran prior to 1958; the dumping in 1963 at Garroch head, on the Clyde, of material from the clear-up of a former radium factory at Balloch.

In checking these historic records, Departments have in addition identified instances when liquid wastes or sludge containing small amounts of radioactivity were dumped at sea through dispersion into the water column from ships. These disposals were from the naval dockyards at Chatham and Rosyth into the North sea beyond the Thames estuary and the Firth of Forth respectively during the mid to late 1960s and early 1970s; sludges from industrial sources containing enhanced natural radioactivity into the Liverpool bay area, and possibly Morecambe bay and the Humber estuary, during the early to mid 1970s; and mildly radioactive solutions from early experiments at MAFF's Lowestoft laboratory in the North sea in the late 1940s.

Where possible, these reports are being following up to see whether further information can be obtained.

On the evidence of the papers that have been examined, I am advised that, even using cautious assumptions, it is estimated that radiation exposures to the public following any dispersal of radioactivity in the sea would give rise to radiation dose levels well within the International Commission on Radiological Protection recommended dose limit and a small fraction of those arising from natural background radioactivity. Nevertheless, I am arranging for the National Radiological Protection Board to make an independent assessment of this information 324W and anything further that can be found. In particular, I shall ask it to advise me of the radiological significance of the disposals and on whether there is any need for monitoring over and above that which is already undertaken. I shall report further to the House when I have received the board's advice.