X-ray tomography study on the crushing strength and irradiation behaviour of dedicated tristructural isotropic nuclear fuel particles at 1000 °C
X-ray tomography study on the crushing strength and irradiation behaviour of dedicated tristructural isotropic nuclear fuel particles at 1000 °C
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DOI：
10.1016/j.matdes.2019.108382
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发表时间：
2020-02
影响因子：
8.4
通讯作者：
Dong Liu;S. Knol;John R. Ell;H. Barnard;M. Davies;J. Vreeling;R. Ritchie
中科院分区：
文献类型：
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作者：
Dong Liu;S. Knol;John R. Ell;H. Barnard;M. Davies;J. Vreeling;R. Ritchie
研究了PYCASSO中子辐照实验中两种专用的三结构各向异性（TRISO）核燃料粒子PyC-1 （Kernel/Buffer/PyC）和PyC-2 （Kernel/Buffer/SiC/PyC）。对于未辐照的颗粒，在室温（RT）和1000°C下，使用独特的热池结合原位x射线计算机微断层扫描（XCT）成像进行破碎实验。尽管颗粒上的SiC层被认为为TRISO颗粒提供了“机械稳定性”，但结果表明，与高温相比，PyC-2颗粒在1000℃时的抗压强度显著降低（~45%）。在高温和1000℃时，两种颗粒在接触区和随后扩展时的断裂模式都有显著差异。对辐照颗粒（辐照温度1000±20℃，辐照剂量1.08 ~ 1.23 dpa和1.49 ~ 1.51 dpa）进行XCT成像；共研究了250个PyC-1粒子和223个PyC-2粒子，并检测了每种类型的半径/层厚的变化。结果表明，PyC-1颗粒的缓冲致密化程度低于PyC-2颗粒，PyC层在PyC-1颗粒中收缩，而在PyC-2颗粒中膨胀。结果讨论了残余应力如何影响这些颗粒的高温和辐照后行为。
Two types of dedicatedTristructuralisotropic (TRISO) nuclear fuel particles, PyC-1 (Kernel/Buffer/PyC) and PyC-2 (Kernel/Buffer/SiC/PyC) from PYCASSO (Pyrocarbon irradiation forcreepandswelling/shrinkage ofobjects) neutron irradiation experiments, were studied. For unirradiated particles, crushing experiments using a unique hot cell, combined with in situ X-ray computed micro-tomography (XCT) imaging, were conducted at room temperature (RT) and at 1000 °C. Although the SiC layer on the particles is presumed to provide ‘mechanical stability’ to the TRISO particles, results showed a remarkable reduction (~45%) in the crushing strength of the PyC-2 particles at 1000 °C compared to RT. The fracture patterns of the two types of particles, both at the contact zone and on subsequent propagation, differ significantly at RT and 1000 °C. Further, irradiated particles (irradiation temperature: 1000 ± 20 °C; irradiation doses: 1.08–1.23 dpa and 1.49–1.51 dpa) were imaged by XCT; 250 PyC-1 particles and 223 PyC-2 particles were studied in total and the change in radius/layer thickness in each type was examined. It was found that the buffer densification was lower in PyC-1 particles compared to PyC-2 particles, and the PyC layer shrank in the PyC-I particles, whereas it expanded in PyC-2. Results are discussed in terms of how the residual stresses can impact the high-temperature and post-irradiation behavior of these particles.