METHOD FOR SEPARATING PLUTONIUM BY USING CROWN COMPOUND OUT OF FISSION PRODUCT IN INITIAL STAGE OF REPROCESSING OF URANIUM AND IRRADIATED NUCLEAR FUEL

摘要

PURPOSE: To enhance the extraction efficiency of Pu by bringing an aq. soln. containing U, Pu and a fission product into contact with a org. soln. containing a crown compd. and subsequently bringing the same into contact with water or an aq. soln. composed of an aq. nitric acid soln. before bringing the same into contact with an aq. soln. of a hydrophilic acid. CONSTITUTION: One vol. of aq. soln. A0 containing U, Pu and a fission product(PF) is brought into contact with two vol. of an org. extraction solvent O0 (a cis-syn-cis isomer of DCH18C6 in C2 H4 Cl2 ) to obtain a soln. A1 containing PF and an org. solvent O1 containing Pu and U but not almost containing PF. Next, the solvent O1 is washed twice with a 3N nitric acid soln. A2 to recover an aq. soln. A3 containing U but not almost containing Pu and PF and an org. solvent O2 containing Pu and U but not almost containing PF. Thereafter, the solvent O2 is brought into contact with two vol. of water and U is re-extracted with water to further obtain an org. solvent O3 containing a large amt. of Pu and this solvent O3 is brought into contact with a hydrophilic acid A6 such as H2 SO4 to recover Pu.