THE ROLE OF CORRODED IRON OVERPACK MATERIALS ON THE RADIONUCLIDE RELEASE FROM ENGINEERED BARRIER SYSTEMS FOR HIGH-LEVEL WASTE DISPOSAL

摘要

Sorption effects of some actinides onto corroded iron overpack on the performance of the engineered barrier system for high level wastes disposal were analyzed using a one-dimensional mass transport code, RAPRAN. Magnetite and goethite were assumed as iron minerals formed in the corroded overpack layer under reducing and oxidizing conditions, respectively. The distribution coefficients of Pu, Np, and Am taken from a recent experimental study were referred to and the extent of the overpack corrosion was parametrically treated in the performance analysis. Results of the analysis indicated that the corroded iron overpack possibly produced effective reduction of the radioactive hazard of the above actinides at the outer boundary of the engineered barrier system, especially in cases of the conservative oxidizing condition, due to the high sorption ability of goethite.