Evaluation of nuclides migration for trench-type disposal by a calculation method taking leaching into consideration

Totsuka, Masayoshi; Kurosawa, Ryohei*; Sakai, Akihiro ; Nakata, Hisakazu ; Hayashi, Hirokazu ; Amazawa, Hiroya

Japan Atomic Energy Agency is planning for the near surface disposal of low level radioactive wastes generated from research, industrial and medical facilities industry in Japan. This document provides the values of radioactivity concentrations equivalent to dose criterion for trench-type disposal. These values are derived based on the safety assessment for ground water scenarios by using a model which describes the release of radionuclides from wastes to a cover soil caused by elution. These concentrations are compared with the one calculated by a model that describes the nuclide release mechanisms as solid-liquid partitioning equilibrium. Additionally, the change in the concentrations is evaluated when the amount of water percolating into a disposal facility varies.