Radiological characterisation of LLW arising from JAERI Tokai Research Establishment

Okoshi, Minoru; Sakai, Akihiro ; Abe, Masayoshi; Tanaka, Mitsugu

As the result of research activities for nuclear energy utilization over 45 years, large amounts of low-level radioactive waste (LLW) are stored at Tokai Research Establishment of JAERI. In order to plan the disposal program, JAERI carried out the radiological characterization of the waste. The results show that about 34,400 tons of LLW will arise from the operation and dismantling of the facilities by the end of 2045. The total activities of beta- and gamma-radionuclides and alpha-radionuclides are about 44 PBq and 56 TBq, respectively. By using the estimated total weight and radioactivities of the waste, important radionuclides were selected from the viewpoint of safety according to the performance assessment of near surface disposal facilities. As the results, twenty-seven radionuclides including twelve alpha-ray emitting actinides were selected as the candidate important radionuclides. Those are slightly different from important radionuclides selected for commercial nuclear power plants because of materials used for facilities and so on.