摘要
为适应钍基熔盐堆核燃料水法后处理的需求,需将乏燃料中难溶的氟化物转化为相应的氧化物形式,因此提出了高温水解的方法来实现这一目的。研究了UF4、ThF4在不同反应温度和反应时间下的高温水解行为,对其水解产物进行了结构表征和溶解实验的研究。结果表明,UF4、ThF4分别在300℃和350℃即可全部转化为相应的氧化物UO2.25和ThO2。溶解实验结果表明,二者的高温水解产物较易溶解在3mol/L HNO3和Thorex试剂中。
To meet the needs of the aqueous-reprocessing of used fuel from thorium molten salt reactor,the insoluble fluorides need to be converted into their corresponding oxides form.To realize this,apyrohydrolysis method was proposed.The pyrohydrolysis behavior of UF4 and ThF4 under different temperature and time was studied,and the structural characterization of the pyrohydrolysis products and the dissolution tests of the products were performed.The results show that,UF4 and ThF4 are entirely converted into their corresponding oxides UO2.25 and ThO2 at 300℃ and 350℃.The results of the dissolution tests show that the pyrohydrolysis products of both UF4 and ThF4 can easily dissolved in 3mol/L HNO3 and Thorex solution,respectively.
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