Pore pressure and swelling in the rim region of LWR high burnup UO2 fuel
Pore pressure and swelling in the rim region of LWR high burnup UO2 fuel
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DOI：
10.1016/s0022-3115(01)00535-9
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发表时间：
2001-06
影响因子：
3.1
通讯作者：
Y. Koo;Byung‐Ho Lee;J. Cheon;D. Sohn
中科院分区：
文献类型：
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作者：
Y. Koo;Byung‐Ho Lee;J. Cheon;D. Sohn
根据测得的 LWR 高燃耗 UO2 燃料的边缘特征，对边缘孔的压力和由于边缘形成而导致的额外颗粒膨胀进行了建模。假设保留在边缘孔隙中的 Xe 原子数量与从边缘基质中耗尽的 Xe 原子数量相同，可以得出过量孔隙压力是温度、颗粒平均燃耗和孔隙半径的函数。据计算，具有小半径的边缘孔在高燃耗时处于高度超压状态。与实验数据的比较表明，虽然用最佳估计边缘宽度获得的颗粒膨胀被低估，但用保守边缘宽度计算的颗粒膨胀与边缘燃耗在 50 至 65 GWd/tU 之间的测量数据非常吻合。另一方面，测得的 85 GWd/tU 膨胀大约介于两个计算值之间。
Based on measured rim characteristics of LWR high burnup UO2fuel, the pressure of rim pores and the additional pellet swelling due to rim formation have been modeled. Using the assumption that the number of Xe atoms retained in the rim pores is the same as that which is depleted from the rim matrix, excessive pore pressure is derived as a function of temperature, pellet average burnup and pore radius. The rim pores with small radii are calculated to be highly overpressurized at high burnup. Comparison with experimental data shows that, while the pellet swelling obtained with best-estimate rim width is underpredicted, the one calculated with conservative rim width agrees well with the measured data for rim burnups between 50 and 65 GWd/tU. On the other hand, the measured swelling at 85 GWd/tU is about in-between the two calculations.