Present status and problems in countermeasures utilizing RIs to environmental pollution

The situation in Japan of the countermeasures using radioisotopes to environmental pollution is described: namely utilization of direct irradiation on contaminants. Those involved in the usage of RIs are the environmental elements containing contaminants, which are air, water, food, soil and refuse. The effect of radiation is essentially the degeneration of contaminants in order to facilitate their further treatment and disposal. Since the dose of radiation and the quantity of objectives are both large, the aspects of safety, economy, toxicity and resource must be examined sufficiently beforehand. With increase of nuclear power generation in the future, the usage of the resultant RIs is also significant. (Mori, K.)