Influence of alpha and gamma radiolysis on Pu retention in the solvent TBP/kerosene

Abstract

Abstract. In light of the issue of radiolysis of the solvent system in PUREX process, alpha and gamma radiation stability of tributyl phosphate (TBP)/kerosene (OK) have been studied in this paper, in which 238 Pu dissolved in the organic phase and 60 Co are selected as alpha and gamma irradiation sources, respectively. The amount of the degradation products not easily removed after the washing process has been measured by the plutonium retention. The effects of the absorbed dose, the TBP volume fraction, the cumulative absorbed dose and the presence of UO 2 2+ and Zr 4+ on the radiolysis of the solvents have been investigated. The results have indicated that the Pu retention increases with the increase of the absorbed dose after alpha or gamma irradiation, and is larger for the solvent containing less TBP. There is competition between UO 2 2+ and Pu 4+ to complex with the degradation products, and Zr 4+ accelerates the radiolysis of the system.

Neutronic and fuel cycle comparison of uranium and thorium as matrix for minor actinides bearing-blankets

“…A "hotter" fuel assembly will require extended cooling time before handling is possible or more expensive handling devices. Similarly, an equilibrium between longer cooling time and decreased reprocessing performances will have to be found as more active fuels degrades reprocessing efficiency [25]. Time evolution of decay heat in the spent blanket assemblies can be separated in two steps as seen in Figure 10.…”

The Design and Verification of a TBP/OK Pyrolysis Incineration Stable System

“…Tributyl phosphate (TBP) is a widely used extractant in the nuclear industry and kerosene (OK) is selected as the diluent of TBP for the separation of uranium and plutonium in most cases [1]. After several extraction cycles, the performance of the TBP/OK solvent reduces because of the irradiation of radionuclides, such as 90Sr and 137Cs [2,3]. Thus, the treatment of radioactive waste organic solvent TBP/OK [4,5] is essential in the plutonium uranium reduction extraction process (PUREX) [6][7][8].…”

Characterization of palladium species after γ-irradiation of a TBP–alkane–Pd(NO3)2system

“…3 Since the 1950s, many studies have been focused on the investigation of the stability of TBP and diluent under radioactive stress. 3,4 In particular, the inu-ence of the irradiation source (a-irradiation vs. g-irradiation [5][6][7][8][9][10][11][12] ), diluent, 5,13-16 nitric acid concentration, [17][18][19][20][21][22] and temperature 14 have been studied. It appears that irradiation of TBP in alkane diluents in contact with aqueous nitric acid solution produces dibutyl phosphoric acid (HDBP), monobutylphosphoric acid (H 2 MBP), phosphoric acid (H 3 PO 4 ), higher molecular weight dimers, acidic phosphates, hydroxylated and nitro-substituted phosphates, and low-molecular weight acid phosphates.…”