A novel approach for preferential recovery of Sr from (Sr, Th)O2

► A novel approach for preferential leaching of Sr(II) from (Th,Sr)O2. ► Kd of Sr(II), Th(IV), Zr(IV), Y(III), Pd(II), Eu(III) and Cs(I) in DTBCH18C6. ► Purification of Sr(II) from Th(IV), Eu(III) and Cs(I) using DTBCH18C6 in HClO4. ► Possible application of the data in reducing the hazardousness of high level waste. ► Possibility of recovery of 90Y, wealth from nuclear waste. Quantitative leaching of Sr from homogeneous and calcined (Th,Sr) O2 in dilute perchloric acid medium suggests the possibility of reducing the hazardousness of discharged nuclear fuel by separation of 90Sr, 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 90Sr can be employed as a compact heat source and as parent radionuclide for 90Y (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 85Sr(II), Th (IV), Zr(IV), Y(III), Pd(II) as well as 152Eu(III) and 137Cs (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)O2 as well as for uptake of Sr by Sr selective chromatographic resin.