PROCESS FOR SEPARATING URANIUM AND THORIUM FROM SPENT NUCLEAR FUELS

摘要

1362410 Processing spent nuclear fuel FARBWERKE HOECHST AG 23 Nov 1971 [24 Nov 1970] 54370/71 Heading G6R In the recovery of uranium and thorium from an aqueous nitrate solution of spent nuclear fuel by means of an organic extractant, the separation from fission products is improved by complexing the fission products with ethylene diamine tetraacetic acid (EDTA) or a salt thereof. Preferably the aqueous feed contains excess nitric acid. In examples, mixed thorium and uranium carbides are burned to oxides, which are dissolved in nitric acid and extracted with a solution of tributyl phosphate (TBP) in dodecane; the organic extract is scrubbed with an aqueous solution of di-sodium ethylene diamine tetra-acetate, and is then contacted with nitric acid in two further stages to separate uranium and thorium. Other organic extractants referred to are methylisobutyl-ketone, dibutoxy-diethyl ether, a solution of di-sec-butyl phenyl phosphonate in diethylbenzene, and a solution of TBP in kerosine. Reference is also made to adding the EDTA or salt to the feed solution.