Long-term environmental problems of radioactively contaminated land

Abstract

This paper examines the various sources of radiological land contamination; its extent; its impacts on man, agriculture, and the environment; countermeasures for mitigating exposures; radiological standards; alternatives for achieving land decontamination and cleanup; and possible alternatives for utilizing the land. The major potential sources of extensive long-term land contamination with radionuclides, in order of decreasing extent, are nuclear war, detonation of a single nuclear weapon (e.g. terrorist act), serious reactor accidents, and nonfission nuclear weapons accidents that disperse the nuclear fuels (termed) “broken arrows”). Over the long term, external radiation doses are dominated primarily by 137Cs and internal radiation doses primarily by 90Sr. Plutonium and the transuranic elements are also important, primarily because of their long half-lives and relatively high inhalation doses. Costs for cleanup of contaminated land are very high. For example, cleanup of the broken arrow in Palomares, Spain, was approximately $33,600 per hectare. If cleanup of agricultural land is impractical, alternative land uses might include production of fiber crops, seed-stock crops, or plant biomass for alcohol fuels, or diversion of the land from crop production. Conversion of cropland to pasture or rangeland takes benefit from the generally lower accumulation of radionuclides into animals products compared with plant products. Another alternative is to fence off the land and use it for production of timber. This alternative would allow for 25–100 y or more of radiological decay before recovery of the timber.