Abstract Extensive study on a variety of symmetric trialkyl phosphates (TalP) has revealed that tris(2-methylbutyl) phosphate (T2MBP) could be considered as a promising alternate extractant to tri-n-butyl phosphate (TBP) for various solvent extraction procedures, especially in the case of fast reactor fuel reprocessing. However, the highly radioactive nature of the dissolver solution generated from spent fuel urges for understanding the radiolytic stability of T2MBP. In this context, a comparative analysis on the alpha and gamma radiation stability of TBP and T2MBP in n-dodecane (n-DD) has been determined by exposing the solvent to different levels of absorbed dose using 239Pu and 60Co sources, respectively. Similar experiments were performed with tri-n-amyl phosphate (TAP) to highlight on the effects of structure of TalP on the extent of radiation induced damage. The effects of the absorbed dose and the concentration of TalP on degree of degradation were investigated by evaluating the deviation in the extraction ability of Zr(IV) and Pu(IV) with various gamma irradiated solvent systems. In addition, the stripping studies were performed for Zr(IV) and Pu(IV) loaded organic phase (1.1 M TalP/n-DD) before and after gamma irradiation. The results have indicated that there is an increase in the metal extraction and decrease in the metal ion stripping tendency with the increment in the absorbed gamma dose. The impact of α-degradation for 1.1 M TalP/n-DD was studied by analyzing their plutonium retention behaviour as a function of time. Overall it has been observed that the stripping behaviour of alpha and gamma irradiated TBP and T2MBP solutions are better compared to TAP system. An attempt has also been made to identify the degradation products upon irradiation for TAP and T2MBP based systems using IR and GC-MS spectroscopic techniques.

中文翻译：

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三正烷基磷酸酯和三（2-甲基丁基）磷酸酯的 α 和 γ 降解行为：一项比较研究

摘要 对多种对称磷酸三烷基酯 (TalP) 的广泛研究表明，磷酸三 (2-甲基丁基) 酯 (T2MBP) 可被认为是磷酸三正丁酯 (TBP) 的有前途的替代萃取剂，适用于各种溶剂萃取程序，特别是在快堆燃料后处理的情况下。然而，由乏燃料产生的溶解器溶液的高放射性性质迫切需要了解 T2MBP 的辐射稳定性。在这种情况下，通过分别使用 239Pu 和 60Co 源将溶剂暴露于不同水平的吸收剂量，确定了 TBP 和 T2MBP 在正十二烷 (n-DD) 中的 α 和 γ 辐射稳定性的比较分析。用磷酸三正戊酯 (TAP) 进行了类似的实验，以突出 TalP 结构对辐射诱导损伤程度的影响。吸收剂量和 TalP 浓度对降解程度的影响通过评估 Zr(IV) 和 Pu(IV) 与各种伽马辐照溶剂系统的提取能力的偏差进行了研究。此外，在伽马辐射之前和之后，对载有 Zr(IV) 和 Pu(IV) 的有机相 (1.1 M TalP/n-DD) 进行了剥离研究。结果表明，随着吸收伽马剂量的增加，金属提取量增加，金属离子剥离趋势降低。通过分析作为时间函数的钚保留行为，研究了 1.1 M TalP/n-DD α-降解的影响。总的来说，已经观察到α和γ辐照的TBP和T2MBP溶液的剥离行为比TAP系统更好。还尝试使用 IR 和 GC-MS 光谱技术鉴定基于 TAP 和 T2MBP 的系统在辐照时的降解产物。