Radiation stability and radiolysis mechanism of hydroxyurea in HNO3 solution: Alpha, beta, and gamma irradiations
Radiation stability and radiolysis mechanism of hydroxyurea in HNO3 solution: Alpha, beta, and gamma irradiations
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DOI：
10.1016/j.net.2022.07.027
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发表时间：
2022-08
影响因子：
2.7
通讯作者：
Yilin Qin;Wei Liao;T. Lan;Feng-rui Li;Feize Li;Jijun Yang;J. Liao;Yuanyou Yang;Ning Liu
中科院分区：
文献类型：
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作者：
Yilin Qin;Wei Liao;T. Lan;Feng-rui Li;Feize Li;Jijun Yang;J. Liao;Yuanyou Yang;Ning Liu
羟基脲（HU）是一种新型无盐还原剂，可用于先进的PUREX流程中U/Pu的分离。在这项工作中，通过检查射线类型（α，β和γ辐照），吸收剂量（10-50 kGy）和HNO 3浓度（0-3 mol L−1）的影响，系统地研究了HU在溶液中的辐射稳定性。对HU辐解速率的影响程度依次为吸收剂量>射线种类> HNO 3浓度，但后两者对HU辐解产物的影响程度中等，其中NH 4+和NO2−含量最高，表明在研究辐照效应时应考虑α、β和γ射线的差异。利用密度泛函理论（DFT）对HU的辐解机理进行了探讨，提出了HU辐解的主要途径，表明HU的辐解主要是·H、eaq-、H2O、中间体和HU辐解自由基碎片之间的自由基反应。本文的结果为进一步了解HU在α、β和γ辐照下的辐解机理提供了有价值的见解，为HU在乏燃料后处理中的应用提供了可靠的数据支持。
Hydroxyurea (HU) is a novel salt-free reductant used potentially for the separation of U/Pu in the advanced PUREX process. In this work, the radiation stability of HU were systematically investigated in solution by examining the effects of the type of rays (α, β, and γ irradiations), the absorbed dose (10–50 kGy), and the HNO3concentration (0–3 mol L−1). The influence degree on HU radiolysis rates followed the order of the absorbed dose > the ray type > the HNO3concentration, but the latter two had moderate effects on HU radiolysis products where NH4+and NO2−were found to be the most abundant ones, suggesting that the differences of α, β, and γ rays should be considered in the study of irradiation effects. The radiolysis mechanism was explored using density functional theory (DFT) calculations, and it proposed the dominant radiolysis paths of HU, indicating that the radiolysis of HU was mainly a free radical reaction among ·H,eaq–, H2O, intermediates, and the radiolytic free radical fragments of HU. The results reported here provide valuable insights into the mechanistic understanding of HU radiolysis under α, β, and γ irradiations and reliable data support for the application of HU in the reprocessing of spent fuel.