Formation of (Cr,Al)UO4 from doped UO2 and its influence on partition of soluble fission products
Formation of (Cr,Al)UO4 from doped UO2 and its influence on partition of soluble fission products
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DOI：
10.1016/j.jnucmat.2013.07.038
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发表时间：
2013-11-01
影响因子：
3.1
通讯作者：
Middleburgh, S. C.
中科院分区：
文献类型：
--
作者：
Cooper, M. W. D.;Gregg, D. J.;Middleburgh, S. C.
CrUO 4和（Cr，Al）UO 4已通过溶胶-凝胶法制备，使用衍射技术和经验对势建模研究。通过原子尺度模拟，预测Cr2 O3优先形成CrUO 4而不是进入溶液进入超化学计量的UO 2 +x。此外，据预测，CrUO 4的形成可以通过从UO 2晶格中除去过量的氧来进行。合成AlUO 4的尝试失败了，取而代之的是形成了U3 O 8和Al 2 O 3。X射线衍射证实了CrUO 4的结构，并首次确定了（Cr，Al）UO 4相的存在（最大Al与Cr的摩尔比为1：3）。模拟随后被用来预测从超化学计量的UO 2 +x中去除裂变产物或燃料添加剂以及将其并入次级相的分配能。的分配能是一致的，只有较小的阳离子（如Zr 4+，Mo 4+和Fe 3+）驻留在CrUO 4，而所有的二价阳离子被预测留在UO 2 +x。添加铝的分配行为的影响不大。由于形成CrUO 4而导致的UO 2 +x的还原对其他裂变产物的溶解极限具有重要意义，因为许多物质在UO 2中的溶解度低于UO 2 +x。皇冠版权所有（C）2013由爱思唯尔B. V.出版保留所有权利。
CrUO4 and (Cr,Al)UO4 have been fabricated by a sol-gel method, studied using diffraction techniques and modelled using empirical pair potentials. Cr2O3 was predicted to preferentially form CrUO4 over entering solution into hyper-stoichiometric UO2+x by atomic scale simulation. Further, it was predicted that the formation of CrUO4 can proceed by removing excess oxygen from the UO2 lattice. Attempts to synthesise AlUO4 failed, instead forming U3O8 and Al2O3. X-ray diffraction confirmed the structure of CrUO4 and identifies the existence of a (Cr,Al)UO4 phase for the first time (with a maximum Al to Cr mole ratio of 1:3). Simulation was subsequently used to predict the partition energies for the removal of fission products or fuel additives from hyper-stoichiometric UO2+x and their incorporation into the secondary phase. The partition energies are consistent only with smaller cations (e.g. Zr4+, Mo4+ and Fe3+) residing in CrUO4, while all divalent cations are predicted to remain in UO2+x. Additions of Al had little effect on partition behaviour. The reduction of UO2+x due to the formation of CrUO4 has important implications for the solution limits of other fission products as many species are less soluble in UO2 than UO2+x. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.