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The liquid–liquid extraction, recovery of Np(VI) and Np(V) from the solution of Na2CO3 by methyltrioctylammonium carbonate in toluene was investigated. By the graphic slope analyses method, as well as by recording of absorption spectra for obtained solutions and method of calculated determination of solution properties taking into account water activity, composition was established for the carbonate complexes of Np(VI) and Np(V) being extracted, which, depending on extraction conditions, can be expressed by the following formulae's: (R4N)2[NpVIO2(CO3)2], (R4N)3[NpVO2(CO3)2], (R4N)6[NpVIO2(CO3)4], (R4N)2[NpVIO2(CO3)2]·2(R4N)2CO3, (R4N)5[NpVO2(CO3)3], (R4N)7[NpVO2(CO3)4], (R4N)3[NpVO2(CO3)2]·(1–2)(R4N)2CO3, where R4N is the quaternary ammonium cation. The results have been obtained in the experiments, has much interest both in the field of alkaline radioactive waste management and with respect to their usage for extraction of transuranium elements during reprocessing of alkaline radioactive waste, as well as for liquid–liquid extraction purification of uranium and plutonium from admixtures of fission products. These techniques are used within the framework of a new alternative method for reprocessing of spent nuclear fuel in carbonate media the CARBEX (CARBonate EXtraction) process. [ABSTRACT FROM AUTHOR]

Production of no-carrier-added (NCA) Pd, which will decay to Rh, was experimented using the Nb(B, 3n)Pd reaction. The 36 MeV boron beam on natural niobium generated 1 MBq/µA.h yield of Pd along with minute contaminants. A chemical separation method based on the liquid-liquid-extraction (LLX) was developed for the separation of trace amount of Pd from the bulk Nb. Stable isotopes of Pd and Nb were used to simulate the reaction with the help of inductively coupled plasma-optical emission spectroscopy (ICP-OES). A high separation factor (~10) was achieved at the optimum separation condition. [ABSTRACT FROM AUTHOR]

Solvent extraction studies on the purification of uranium from zirconium rich sodium diuranate (SDU) feed was carried out using n-tri butyl phosphate (TBP) as extractant and n-decanol as phase modifier. The presence of Zr in SDU leached solution leads to the formation of third phase during liquid-liquid extraction of uranium which was successfully prevented by addition of n-decanol in 30% (v/v) TBP/ n-dodecane mixture. A seven stage counter current extraction of SDU feed solution followed by five stage stripping were carried out using optimum concentration of phase modifier 15% n-decanol-30% TBP in n-dodecane as solvent. Based on the findings a process flow-sheet has been developed for the purification of SDU to nuclear grade ammonium diuranate. [ABSTRACT FROM AUTHOR]