The Solubility of Pu(Ⅳ) Hydroxide and Pu Dioxide in Simulated Groundwater Solutions (SGW) under Various Conditions

摘要

As a result of weapons plutonium production and functioning of spent nuclear fuel reprocessing plants, there were accumulated great volumes of radioactive waste in some countries. The most dangerous long-lived radionuclides―transuranium elements (TRU)―were released into geologic formations, ground- and seawater. The prediction of an aquatic behavior of TRU required a fundamental database consisting of solubility values of actinide hydroxides and oxides, especially of Pu ones. However, the reported values are often scattered, especially for tetravalent actinide hydroxides and oxides; there are very large differences of several orders of the magnitude between the lowest and highest values. Therefore, it is of great interest to obtain additional information, particularly regarding the solubility of Pu(OH)_4 and PuO_2 in near-neutral groundwater solutions simulating those expected in the sites of HLW deep geological disposals.