A Critical Study on the IAEA Definition of High Level Radioactive Waste Unsuitable for Dumping at S e a

Abstract

The definition of high level radioactiv e waste and other high level radioactive matter not suitable for dumping at sea has been given by IAEA (1975). Since this definition is based on the report by WEBB and MORLEY (1973), a critical study is made on their report. The result of study shows that owing to the assumption of a very small value of the horizontal eddy diffusion coefficient (10⁴ cm²/s) for the sake of safety for these nuclides, the limiting environmental capacity for such nuclides as ²²⁶Ra and ²³⁹Puwith longer half-lives is extremely overestimated. And due to a very small value of a daily intake of marine foods (6 g/d) and a larger value of the ratio of nuclidic concentrations between the top of the deep layer and the surface layer (100), the environmental capacity is also overestimated for every nuclide. It is proposed that the definition of high level radioactive waste should be reassessed carefully by experts in various countries.