Development of safety assessment methodology considering the evolution of geological disposal system, 2; Analysis of long-term behavior of engineered barrier system using systematized evaluation models

Mukai, Masayuki ; Kataoka, Masaharu; Iida, Yoshihisa ; Maeda, Toshikatsu; Hirota, Naoki; Yamaguchi, Tetsuji ; Tanaka, Tadao 

Performance evaluation models for engineered barriers and estimation methods for radionuclide migration parameters have been developed to establish a method of long-term safety assessment for geological disposal simulating a variety of environmental conditions of deep underground in Japan. In order to make the safety assessment more systematic and reasonable, the parameters used in radionuclide migration analysis should reflect spatially and temporally changeable conditions of the engineered barriers. Moreover, the changeable conditions should be quantified based on the calculation in which models and parameters for the barrier materials are systematically linked with each other. In this study, a sequence of the systemized procedure was configured and was tested to pick out parameters having significant influence to the safety function of the buffer material from results of long-term performance analysis on engineered barrier system.