Distribution and Solubility of Radionuclides and Neutron Absorbers in Waste forms for Disposition of Plutonium Ash and Scraps, Excess Plutonium, and Miscellaneous Spent Nuclear Fuels

[摘要] Successful immobilization of actinides (Am, Cm, Th, Pu, Np, etc.) in crystalline and amorphous host matrixes with appropriate neutron absorbers (B, Hf, Gd, etc.) requires sound scientific knowledge of the local chemical environments of both the actinides (An) and the neutron absorbers and their interaction with the host matrixes. This understanding leads to a more systematic and efficient approach to predicting solubilities than the strictly empirical approach now used. The goals of this ongoing research are to determine solubility limits of representative actinides (Pu and U) and neutron absorbers (Hf and Gd) in crystalline and amorphous matrixes and to determine solution mechanisms of these species in the two types of systems. Actinides and neutron absorbers in amorphous systems have been studied at PNNL in collaboration with LBNL and University of Michigan and in crystalline systems at ANSTO. We believe that we are in a position to understand the chemical systematics of silicate melts so that the solubility of actinides, neutron absorbers, and, we would suggest, other metal species in glass no longer must be determined empirically but can be calculated from a set of equilibrium constants in a fashion similar to aqueous systems.

[发布日期] 2000-06-01 [发布机构] Pacific Northwest National Laboratory (U.S.)

[关键词] Solubility;Spent Fuels;Ansto;Actinides;37 Inorganic, Organic, Physical And Analytical Chemistry