Progress in TRU chemistry. TRU chemistry for geologic disposal of radioactive waste

The basic interests in transuranium (TRU) chemistry is to characterize f-block elements. Recently, TRU chemistry has been paid attention from an aspect of geologic disposal. Since TRU is highly harmful and its isotopes have long half-life, these are important elements for evaluation of radio-active wastes and used fuels. This report describes recent progress of studies on TRU in geologic disposal referring the research reports at Migration Conference, an international conference. The diffusion coefficients (Kd) of various elements including TRU for different kinds of rocks, soils and minerals were determined. Sorption Database was constructed by collecting previous data on sorption and sorption models were designed to explain ion behaviors, especially those of heavy metal ions in environmental water. However, these modeling are still unsatisfactory. These results indicate that TRU study and studies on its sorption species are essential to progress the modeling study. (M.N.)