Fabrication and properties of SiC-based accident-tolerant fuel with precisely-regulated TRISO particles dispersion

Abstract The ceramic-based coated particle dispersed fuel (CDF) has arrested worldwide attention as a kind of promising accident-tolerant fuel since the Fukushima-Daiichi accident in 2011. To improve safety and in-pile performance, regularly-distributed CDF was formulated. A novel fabrication method was developed to accurately target TRistructural-ISOtropic (TRISO) particles to preset positions in the SiC matrix via a self-developed precise TRISO-controlled moulding equipment. After sintering, the samples were observed by SEM and X-μCT, which showed that the TRISO particles were uniformly and regularly arranged in the SiC matrix, and were almost intact with little extrusion and breakage. The density, thermal conductivity, and thermal shock performance of the prepared samples were examined and proved to be consistent with those of the pellets with randomly-distributed TRISO particles, which could satisfy the safety requirements. Small batch manufacturing was realized and production efficiency was enhanced. This new technology offers a promising pathway to produce high-reliability ceramic-based CDF with precisely-located TRISO particles, which promote the development of advanced accident-tolerant fuels.