Optimisation approach of ALARA in nuclear practice: An early application of the precautionary principle? Scientific uncertainty versus legal uncertainty and its role in tort law

The late health effects of exposure to low doses of ionising radiation are subject to scientific controversy: one view finds threats of high cancer incidence exaggerated, the other view thinks the effects are underestimated. Both views have sound scientific arguments in favour of them. Since the nuclear field, both in industry and medicine, has had to deal with this controversy for many decades, one can argue that the optimisation approach to keep the effective doses as low as reasonably achievable, taking economic and social factors into account (ALARA), is a precautionary approach, because for stochastic effects of low doses, no conclusive scientific proof can be provided. This paper explores how ALARA and the precautionary principle are influential in the legal field and, in particular, in tort law because liability should be a strong incentive for safer behaviour. This so-called "deterrent effect" of liability seems to evaporate in today's technical and highly complex society, in particular when dealing with the late health effects of low doses of ionising radiation. Two ma in issues will be dealt with in the paper: 1. How are the health risks attributable to "low doses" of radiation regulated in nuclear law and what lessons can be learned from the field of radiation protection? 2. How can ALARA inform the discussion of the precautionary principle and vice-versa, in particular so far as legal sanctions and liability are concerned? It will be shown that the precautionary principle has not yet enough been implemented into nuclear law. Another conclusion is that the meaning given to technical and legal terminology, used in general principles, differs fundamentally, giving rise to more legal uncertainty and possibly to a lack of appropriate legal consequences and sanctions.