Outline of the disposal of very low level concrete waste in JAEA

Tsuji, Tomoyuki 

Japan Atomic Energy Agency (JAEA), who conducted the demonstration test on a safe dismantling of Japan Power Demonstration Reactor (JPDR) in Nuclear Science Research Institute, has been performing the safe demonstration test of near-surface disposal of very low level (VLL) concrete waste arising from JPDR dismantling. Approximately 1,700 tons of VLL concrete wastes were placed in a simple disposal facility, of which dimensions are 45 m16 m and 3.5 m in depth without any engineered barrier, and covered with soil of 2.5 m thickness. The safe demonstration test of near-surface disposal of VLL concrete waste consists of a operation stage (FY 1995-1996) and a management stage (FY 1996-2024). In the operation stage, radiation dose around the disposal facility was measured, and radioactivity concentrations in groundwater and soil were analyzed. After we proceeded the management stage of disposal, radiation monitoring was continued additionally for 3 years in the management stage. An inspection such as no outflow, crack and subsidence of the covered soil is conducted at once a week. The radiation monitoring data is planned to storage properly by management department until the finishing of management stage, and an inspection data is stored in accordance with the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors.