Field tests on migration of TRU-nuclide, 3; Migration test of radionuclide in aerated soil layer

Mukai, Masayuki ; Tanaka, Tadao ; Maeda, Toshikatsu; Ogawa, Hiromichi; Matsumoto, Junko ; Munakata, Masahiro ; Zhao, Y.*; Guo, Z.*; Ni, S.*; Li, S.*

Evaluation of radionuclide migration in geologic media is of great importance in safety assessment for shallow land disposal specially for TRU nuclides because of inadequate data based on field test. As a cooperative research between JAERI and CIRP, a field test of radionuclide migration was conducted under natural condition using Sr-90, Np-237 and Pu-238 to obtain migration data of the radionuclides in actual aerated layer under natural rainfall condition. Values of input parameters to an existing evaluation equation of nuclide migration were determined on the basis of the results of laboratory experiments of batch and column methods and field investigation. Migration distribution of the radionuclides calculated with the determined values showed reasonable agreement with the measured distribution of the field test. This confirmed an applicability of the evaluation equation for radionuclide migration to actual aerated layer under natural condition.