Molecular Hydrogen Yields from the a-Self-Radiolysis of Nitric Acid Solutions Containing Plutonium or Americium.
Molecular Hydrogen Yields from the a-Self-Radiolysis of Nitric Acid Solutions Containing Plutonium or Americium.
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含有钚或镅的硝酸溶液的α-自辐射分解产生分子氢。
DOI：
10.1021/acs.jpcb.7b12267
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Gregson CR
中科院分区：
文献类型：
--
作者：
Gregson CR
本文研究了含钚或镅的硝酸及其与硫酸的混合物的α辐解中分子氢产率与硝酸浓度的关系。实验测量与Monte Carlo辐射轨道化学模型预测的比较表明，除了清除水合电子，其前体，和氢原子，激发态水的淬火是重要的，在控制分子氢的产量。此外，溶液酸度的增加导致径迹反应的显著变化，这可以解释为Haq+清除eaq-形成H·的结果。虽然钚已被证明是低于0.1 mol dm-3硝酸的分子氢前体的有效清除剂，但以前报道的钚对1 - 10 mol dm-3硝酸的G（H2）α的影响没有重现。模拟结果表明，钚是不可能有效地与硝酸根离子在清除分子氢的前体在较高的硝酸浓度，这是证实了从钚溶液的分子氢产量与那些从镅解决方案进行比较。最后，放射性核素，离子加速器实验和模型预测之间的比较导致的结论是，高剂量率的加速器研究并不显着影响测得的分子氢产率。这些反应提供了对在乏核燃料再处理和高放射性液体废物在玻璃化之前的储存中常见的液体的重要过程的深入了解。
The yield of molecular hydrogen, as a function of nitric acid concentration, from the α-radiolysis of aerated nitric acid and its mixtures with sulfuric acid containing plutonium or americium has been investigated. Comparison of experimental measurements with predictions of a Monte Carlo radiation track chemistry model shows that, in addition to scavenging of the hydrated electron, its precursor, and the hydrogen atom, the quenching of excited state water is important in controlling the yield of molecular hydrogen. In addition, increases in solution acidity cause a significant change in the track reactions, which can be explained as resulting from scavenging of eaq–by Haq+to form H•. Although plutonium has been shown to be an effective scavenger of precursors of molecular hydrogen below 0.1 mol dm–3nitrate, previously reported effects of plutonium onG(H2)αbetween 1 and 10 mol dm–3nitric acid were not reproduced. Modeling results suggest that plutonium is unlikely to effectively compete with nitrate ions in scavenging the precursors of molecular hydrogen at higher nitric acid concentrations, and this was confirmed by comparing molecular hydrogen yields from plutonium solutions with those from americium solutions. Finally, comparison between radionuclide, ion accelerator experiments, and model predictions leads to the conclusion that the high dose rate of accelerator studies does not significantly affect the measured molecular hydrogen yield. These reactions provide insight into the important processes for liquors common in the reprocessing of spent nuclear fuel and the storage of highly radioactive liquid waste prior to vitrification.