FRANCE seems poised to risk further international condemnation over its nuclear policy. This month, leading French scientists will advise the French government to ignore an international recommendation to tighten up radiation safety limits for workers and members of the public.
The French Academy of Sciences is about to publish a report which concludes that there is no scientific basis for more than halving the maximum permitted radiation dose, a move recommended by the International Commission on Radiological Protection in 1990. The ICRP suggests that the maximum dose for nuclear workers should be reduced from 50 to 20 millisieverts a year, and that for the public from 5 to 1 millisieverts a year.
The ICRP鈥檚 new limits have already been adopted by the UN鈥檚 International Atomic Energy Agency and are widely expected to be accepted by the European Union, which is currently drafting a new directive on radiation protection. In Britain, the National Radiological Protection Board is urging the nuclear industry to adopt the new limits pending their endorsement by the EU.
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The NRPB is also proposing a series of tighter advisory limits: a 鈥渄ose constraint鈥� level for the public of 0.3 millisieverts a year and 鈥渋nvestigation levels鈥� of 0.1 millisieverts a year for the public, and 15 millisieverts a year for workers.
But now the 23-strong committee of biologists, physicists and doctors assembled by the French Academy of Sciences at the request of the French government is threatening to wreck the international consensus. The committee鈥檚 report concludes that the ICRP鈥檚 proposed new limit for the public is 鈥渄ifficult to justify鈥� and that there is no 鈥渋ndisputable鈥� scientific reason to lower the limit for workers.
The report鈥檚 conclusions are partly based on recent research in molecular biology conducted by the French atomic energy agency, the CEA, which is represented on the academy鈥檚 committee. Its findings suggest that DNA damaged by very low levels of radiation can be repaired by cell enzymes more easily than previously thought. As a result, the CEA鈥檚 scientists are now arguing that there may be a threshold below which radiation should be regarded as safe.
This is flatly contradicted by Britain鈥檚 NRPB, which has recently completed a report on the issue for the French government鈥檚 Institute for Nuclear Safety and Protection. The NRPB concludes that for radiation protection purposes, it is 鈥渁ppropriate鈥� to assume that there is no threshold. Even the tiniest exposure to radiation, it says, 鈥渉as a finite probability, albeit very low, of generating the specific damage to DNA that results in a tumour-initiating mutation鈥�.
According to a report in the trade magazine Nucleonics Week, one of the CEA鈥檚 radiation biologists; Anne Fleury-Herard, is also discounting international evidence of a high leukaemia rate among nuclear workers. She claims that the high rate is almost entirely due to two British nuclear plants, Sellafield and Dounreay, where the doses received by workers may have been underestimated in official records.
The French academy鈥檚 advice is abruptly dismissed as 鈥渟tupid鈥� by Barry Lambert, a radiation biologist at St Bartholomew鈥檚 Hospital Medical College in London. 鈥淚t is totally unacceptable and ignores all the evidence from the survivors of Hiroshima and Nagasaki,鈥� he says. 鈥淚n France they are prepared to accept a higher risk than anywhere else. The reason is that they depend heavily on nuclear power for their electricity.鈥�
The academy鈥檚 report reveals that its recommendations are disputed by a 鈥渟mall minority鈥� of the committee, said by a spokeswoman for the academy to be no more than two people. The two back the ICRP鈥檚 new limit for workers. And although they believe that there is no scientific basis for lowering the limit for the public, they think that it would 鈥渘ot be desirable for France to dissociate itself from the position of other countries鈥�.