Preferential leaching of Sr from mixed (Th/Sr) oxide

摘要

Preferential leaching of Sr from irradiated thorium may play an important role to facilitate the management of high level waste as well as provide a new route to recover valuable fission product ~(90)Sr which has potential applications as (a) compact heat source and (b) as parent radionuclide for ~(90)Y, used in therapeutic radiopharmaceuticals. In the present work, leaching of Sr from (Th,Sr)O_2 in nitric acid and perchloric acid medium has been investigated as a function of acidity as well as refluxation time. It was interesting to observe that quantitative leaching of Sr(Ⅱ) is possible even at 0.01 M HClO_4 where leaching of Th is negligible (～0.01%). Leaching behavior of other metal ions, like Pd(Ⅱ), Y(Ⅲ), and Zr(Ⅳ), representing few major fission products was also investigated.