Considerations in siting long-term radioactive noble as storage facilities

Projections of future fission reactor capacity indicate that the present practice of releasing radioactive noble gases (primarily krypton-85) to the atmosphere cannot safely be allowed to continue indefinitely. Ongoing research programs are developing methods of extracting and concentrating these waste gases so they may be stored for extended periods, thereby allowing them to decay to relatively safe levels. Anticipating the need for facilities specifically designed for long-term storage of noble gases, we have reviewed some factors which might be considered in developing optimum siting criteria. Among these factors are, above- vs. below-ground storage, meteorology, geography, and demography. The objective used in these considerations is minimization of resulting population doses, both long- and short-term, from a major release, either instantaneous or continuous from the various facilities. Those sites considered are remote islands, continental shorelines, mountain tops, deep water, and inland low-population-density areas. Assuming an equal probability of containment failure at each of the site options, we conclude that siting is relatively inconsequential for long-term population doses. Siting, however, is important for short-term exposures to local populations, especially where there might be a possibility of exceeding Radiation Protection Guides. The relative significance of long- vs. short-term doses resulting from exposures to radioactive noble gases is also discussed