Gamma and beta radiolysis of tri-iso-amyl phosphate: Degradation of tri-iso-amyl phosphate and formation of di-iso-amyl phosphoric acid. (October 2022)

• Record Type: Journal Article
• Authors: Li, Fengzhen; Qin, Yilin; Liao, Wei; Li, Feize; Lan, Tu; Ding, Songdong; Liao, Jiali; Yang, Jijun; Yang, Yuanyou; Feng, Wen; Liu, Ning
• Is Part Of: Radiation physics and chemistry. Volume 199(2022)
• Publication Date: 2022-10
• Subjects: Spent fuel reprocessing -- Tri-iso-amyl phosphate -- di-iso-amyl phosphoric acid -- γ radiolysis -- β radiolysis; Radiation chemistry -- Periodicals; Radiometry -- Periodicals; Radiation -- Periodicals; Chimie sous rayonnement -- Périodiques; 539.2
• DOI: 10.1016/j.radphyschem.2022.110354
• Languages: English
• ISSNs: 0969-806X

Abstract

Abstract: Tri-iso-amyl phosphate (TiAP) is considered a potential alternative solvent to tri-butyl phosphate (TBP) for aqueous reprocessing of molten salt reactors and fast reactor fuels. This study explored the γ and β radiolysis of TiAP under various conditions through the analysis of the radiolytic concentration changes of TiAP and the yields of di-iso-amyl phosphoric acid (DiAP) using gas chromatography. The results indicated that the effects of dose, diluent, and nitric acid on the radiolysis of TiAP under γ-and β-irradiations showed a similar regularity. The degradation rate of TiAP followed a first-order reaction, and the paraffinic diluent was able to sensitize TiAP. Although the presence of nitric acid promoted the radiolysis of TiAP and the formation of DiAP in a neat TiAP system, it did not lead to significant changes in the 36%TiAP/n-DD system, implying that nitric acid is involved in an intricate process. Furthermore, based on these results, possible degradation mechanisms of TiAP were described. Highlights: The γ and β radiolysis of TiAP under various conditions were explored. A method for simultaneous determination of TiAP and DiAP was established. The effect of diluent and nitric acid on the degradation of TiAP and formation of DiAP was provided.