Search

Quantitative leaching of Sr from homogeneous and calcined (Th,Sr) O(2) in dilute perchloric acid medium suggests the possibility of reducing the hazardousness of discharged nuclear fuel by separation of (90)Sr, a prominent fission product at dissolution stage itself rather than the conventional approach of its recovery from high level nuclear waste. Apart from mitigating the radiotoxicity of the nuclear waste, recovered (90)Sr can be employed as a compact heat source and as parent radionuclide for (90)Y (used in therapy radiopharmaceuticals), provided it can be made available at desired high purity. Leaching behavior of few other fission products was also investigated to quantify their contamination in leached Sr. Feasibility of employing extraction chromatography using Sr selective resin was explored in perchloric acid medium. In this context, the distribution coefficients of (85)Sr(II), Th (IV), Zr(IV), Y(III), Pd(II) as well as (152)Eu(III) and (137)Cs (I) were determined under varying nitric acid/perchloric acid concentration and under varying loading conditions of metal ions. Perchloric acid medium appears better than nitric acid medium for preferential leaching of Sr from (Th,Sr)O(2) as well as for uptake of Sr by Sr selective chromatographic resin., (Copyright © 2012 Elsevier B.V. All rights reserved.)

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 90Sr which has potential applications as (a) compact heat source and (b) as parent radionuclide for 90Y, used in therapeutic radiopharmaceuticals. In the present work, leaching of Sr from (Th,Sr)O2 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 0.01M HClO4 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. [ABSTRACT FROM AUTHOR]