Effects of waste solvent contained in asphalt waste on the nuclide solubility and speciation

Shibata, Masahiro ; Mihara, Morihiro  ; Sasaki, Ryoichi; Honda, Akira

In the performance assessment for the geological disposal of the TRU waste, effect of organic material (i.e. organic wastes, cement additives, and natural organism) should be considered. The waste solvent (including TBP and its deterioration products) is contained in the asphalt waste generated from the reprocessing facility of JNC. These solvent and deterioration products have the possibility of forming the complexes with actinide elements if a chemical condition is satisfactory. It influences solubility and the sorption behavior of the radionuclide when the complexes are soluble in aqueous solution. In that case, there is a possibility to influence the behavior of the radionuclide migration. In this report, to evaluate the influence of TBP and its deterioration products (DBP and MBP) on the solubility and the sorption behavior of the actinide, (1) literature survey for the experimental research, (2) survey for the thermodynamics data concerning the interaction with the radionuclide and calculation for solubility and speciation in the expected environments, were conducted. As a result, it was thought that the influences of TBP and its degradation products on the solubility and speciation of radionuclides were small (Times of several in solubility at most).