Study of subsurface disposal concepts for uranium waste, 5

Nakatani, Takayoshi ; Ishitoya, Kimihide; Funabashi, Hideyuki ; Sasaki, Ryoichi*; Kurosawa, Mitsuru*

This study was carried out the evaluation of exposure dose on "Less-likely Scenarios" according to "Basic Policy for Safety Regulation Concerning Land Disposal of Low-Level Radioactive Waste (Interim Report)" (In July 2007, the Nuclear Safety Commission of Japan). When the evaluation modeling was constructed, "Evaluation scenario" and "Fluctuating parameter" were simplified "Physical, chemical change of the disposal system according to the climatic variation and the tectonic movement" that was the event foreseen happening in the future to "Release coefficient from the disposal facilities of the nuclide", "Distribution coefficient of the natural barrier", "Velocity of the underground water", and "Distance of the transfer path". As the result, exposure doses in all cases for "Less-likely scenarios" were less than 300 Sv/y (standard exposure dose of "Less-likely Scenarios").