An overview of postirradiation examination results for uranium nitride kernels and uranium nitride coated particles irradiated in the High Flux Isotope Reactor are presented. This is the first postirradiation examination of the MiniFuel irradiation vehicle that was recently developed to rapidly accumulate burnup during separate effects irradiation testing. In general, the burnup and fuel temperatures measured postirradiation were consistent with the design calculations. The burnup measured by mass spectrometry ranged from 5.9 to 10 MWd/kgU and was achieved after only 68 effective full-power days of irradiation. The dilatometric evaluation of passive silicon carbide thermometry indicated that the fuel was irradiated at temperatures ranging from 410 to 460 °C. Because the irradiation temperatures and burnup were low, the UN kernels showed minimal fission gas release that was within the range of the expected recoil (athermal) release. While it is possible to measure fuel swelling using x-ray computed tomography, the observed swelling was too small to quantify in this case. Extensive microstructural characterization of the irradiated fuel was performed, and no significant irradiation induced changes were observed.

介绍了在高通量同位素反应堆中辐照的氮化铀核和氮化铀涂层颗粒的辐照后检查结果的概述。这是MiniFuel辐照工具的第一次辐照后检查，最近进行了开发，可以在单独的效果辐照测试期间快速累积燃尽。通常，辐照后测得的燃耗和燃料温度与设计计算一致。通过质谱法测量的燃耗范围为5.9至10 MWd / kgU，仅在有效的全功率辐照68天后即可达到。被动碳化硅测温的膨胀计评估表明，该燃料是在410至460°C的温度范围内辐照的。因为照射温度和燃尽低，联合国内核显示的裂变气体释放量最小，处于预期的后坐力（无热）释放范围内。尽管可以使用X射线计算机体层摄影术测量燃料溶胀，但在这种情况下观察到的溶胀太小而无法量化。进行了辐照燃料的广泛的微观结构表征，并且没有观察到显着的辐照引起的变化。