High-Temperature Fuel Technology for Nuclear Process Heat:ZrC-Containing Coated Particle Fuels and High-Density Graphite Fuel Matrices

摘要

This is the final report on the high-temperature, gas-cooled reactor fuels project that was pursued at the Los Alamos Scientific Laboratory from early 1973 to mid-1977. This work followed two broad paths:(1) ZrC was utilized in various ways to improve the temperature capability of fission-product-retaining coated nuclear fuel particles and (2) techniques were developed for fabricating fuel rods by extruding the coated particles in high-density graphite matrices.nThe key to the ZrC coating project proved to be the ZrCl4 powder feeder development. The ZrCL4, reacted with H2 and CH4 or C3H6 to produce chemically vapor-deposited (CVD) ZrC. This CVD ZrC was used on nuclear fuel particles for replacing the SiC in the TRISO-II design, for making ZrC-C graded coats, and for making ZrC-alloyed isotropic carbon coats. Fuel particles with all of the described coats have been very successful in high-temperature, full-fluence (8 × 1021 n cm2) irradiation tests. High-temperature diffusion experiments with cesium showed that ZrC is com parable to SiC as a diffusion barrier.