The cement and concrete used in low level radioactive waste disposal facility

Radioactive wastes forming with research and development of nuclear energy can be roughly divided to 'low level radioactive waste' with low level radioactivity formed from nuclear power plants and other nuclear facilities and 'high level radioactive waste' formed with reprocessing of used nuclear fuels. In Japan, the Japan Nuclear Fuel Ltd. has already begun to conduct processing of the 'low level radioactive waste' formed from nuclear power plants. And, on technical problem on safe processing of 'high level radioactive waste', national institutes and laboratories promoted earnestly its investigations. In this paper, cement and concrete used in low level radioactive waste disposal facilities were introduced. At last, it is described that it is necessary in future to fulfil research and development of evaluation technique on physical and chemical degradation of cement materials and to make upgrading of safety evaluation of land disposal facility to intend upgrading of its safety and economics. (G.K.)