A novel approach for preferential recovery of Sr from (Sr, Th)O<SUB>2</SUB>

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

A 2D DNA Lattice as an Ultrasensitive Detector for Beta Radiations

There is growing demand for the development of efficient ultrasensitive radiation detectors to monitor the doses administered to individuals during therapeutic nuclear medicine which is often based on radiopharmaceuticals, especially those involving beta emitters. Recently biological materials are used in sensors in the nanobio disciplines due to their abilities to detect specific target materials or sites. Artificially designed two-dimensional (2D) DNA lattices grown on a substrate were analyzed after exposure to pure beta emitters, ⁹⁰Sr-⁹⁰Y. We studied the Raman spectra and reflected intensities of DNA lattices at various distances from the source with different exposure times. Although beta particles have very low linear energy transfer values, the significant physical and chemical changes observed throughout the extremely thin, ∼0.6 nm, DNA lattices suggested the feasibility of using them to develop ultrasensitive detectors of beta radiations