부산대학교 도서관

This study aims to provide microstructural characterization for the matrix graphite which molten saltreactors (MSRs) use, and improve resistance to molten salt infiltration of the matrix graphite for fuelelements. Mesocarbon microbeads (MCMB) densified matrix graphite A3-3 (MDG) was prepared by aquasi-isostatic pressure process. After densification by MCMBs with average particle sizes of 2, 10, and16 mm, the pore diameter of A3-3 decreased from 924 nm to 484 nm, 532 nm, and 778 nm, respectively. Through scanning electron microscopy, the cross-section energy spectrum and time-of-flight secondaryion mass spectrometry, resistance levels of the matrix graphite to molten salt infiltration were analyzed. The results demonstrate that adding a certain proportion of MCMB powders can improve the antiinfiltrationability of A3-3. Meanwhile, the closer the particle size of MCMB is to the pore diameter ofA3-3, the smaller the average pore diameter of MDG and the greater the densification. As a matrixgraphite of fuel elements in MSR was involved, the thermal and mechanical properties of matrix graphiteMDG were also studied. When densified by the MCMB matrix graphite, MDGs can meet the molten saltanti-infiltration requirements for MSR operation.