Effects of Secondary Phase Particle Dissolution on the In-Reactor Performance of BWR Cladding
Effects of Secondary Phase Particle Dissolution on the In-Reactor Performance of BWR Cladding
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二次相颗粒溶解对沸水堆堆内堆内性能的影响
DOI：
10.1520/jai103025
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
L. Hallstadius
中科院分区：
文献类型：
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作者：
S. Valizadeh;G. Ledergerber;S. Abolhassani;D. Jädernäs;M. Dahlbaeck;E. Mader;G. Zhou;J. Wright;L. Hallstadius
虽然完整的机制尚未完全理解，它是公认的，第二相粒子（SPP）的尺寸分布和化学成分有一个关键的影响，在反应堆的腐蚀速率和氢的吸收在沸水堆（BWR）包壳。为了进一步研究这些效应，使用透射电子显微镜（TEM）研究了不同选择的具有标准LK 3包壳材料的燃料棒组件，这些燃料棒组件已在KernKraftwerk Leibstadt（KKL）中接受了三个、五个、六个、七个和九个年周期的辐照。样品的TEM分析表明，随着小SPPs在辐照过程中溶解，SPPs的平均尺寸增加。在三个循环后，在整个检查样品范围内，含Fe-Cr的SPP已被鉴定为完全无定形，而含Fe-Ni的SPP保持结晶。对几种含Fe-Ni沉淀物的EDX分析表明，经17.9× 10 ~（21）n/cm ~ 2（>1 MeV）快注量辐照9次后，Fe/Ni比基本保持在1.5 ~ 1.6之间，降到1左右。从这项研究的结果证实，增加的氧化物厚度，较高的氢含量，和加速增长的棒在棒平均燃耗为78 MWd/kgU去沿着变化的外观SPPs通过TEM。
Although the complete mechanisms are not yet fully understood, it is well established that the secondary phase particle (SPP) size distribution and chemical composition have a crucial affects in the reactor corrosion rate and hydrogen uptake in boiling water reactor (BWR) cladding. To further study these effects, different selected fuel rod assemblies with standard LK3 cladding materials that have been irradiated in KernKraftwerk Leibstadt (KKL) for three, five, six, seven, and nine annual cycles were investigated using transmission electron microscopy (TEM). TEM analysis of the samples showed that the average size of SPPs increases as the small SPPs are dissolved during irradiation. After three cycles the Fe–Cr bearing SPPs have been identified as completely amorphous over the whole range of examined samples and the Fe–Ni bearing SPPs remained crystalline. The EDX analyses of several Fe–Ni bearing precipitates show that the Fe/Ni ratio stays more or less constant for the irradiated material at 1.5 to 1.6 and drops to about 1 after fast fluence of 17.9×1021 n/cm2 (>1 MeV) for nine cycles sample. Results from this study confirms that the increased oxide thickness, the higher hydrogen content, and the accelerated growth of the rods at rod average burnup of 78 MWd/kgU goes along with a change in the appearance of SPPs by TEM.