A detailed electron microscopy study was performed on focused ion beam-prepared lamellae from different locations relative to a crack across the inner pyrolytic carbon layer of a neutron-irradiated tristructural isotropic-coated particle. The distribution and composition of fission products across the inner pyrolytic carbon and silicon carbide (SiC) layers were studied. Previously, this crack was identified in the particle that released significant inventory fractions of cesium and silver during irradiation and displayed localized palladium pileup with SiC degradation. In this study, carbon areas were found in the SiC layer close to the crack tip and they had precipitates that consisted mostly of palladium silicides or palladium, with silver and/or cadmium frequently identified. Results confirmed that areas in the SiC layer close to the crack tip with localized accumulation of palladium were corroded by palladium, forming pure carbon areas and palladium silicide that provided pathways for silver, cadmium and cesium migration.

对聚焦离子束制备的薄片进行了详细的电子显微镜研究，该薄片相对于中子辐照的三结构各向同性涂层颗粒的内部热解碳层上的裂缝相对于不同位置。研究了内部热解碳和碳化硅（SiC）层中裂变产物的分布和组成。以前，在裂纹中发现了该裂纹，该粒子在辐照过程中释放出大量的铯和银，并显示出局部钯堆积，且SiC降解。在这项研究中，在靠近裂纹尖端的SiC层中发现了碳区，并且它们的沉淀物主要由硅化钯或钯组成，并且经常发现有银和/或镉。