The application of HTR coated fuel particle performance models to various problems in materials' science

A number of stress models of varying complexity are developed in a high temperature reactor to predict the irradiation performance of coated fuel particles for the HTR system. These are applied to account for experimental observations in the following three fields of materials' science: (1) the increase in failure fraction with time as a bath of irradiated coated particles is annealed at 1600 C, by way of the simulation of a reactor accident, (2) the coefficient of thermal expansion (cte) of copper, loaded with a high concentration of very small krypton gas bubbles as a means of safely immobilizing Kr(85) during the reprocessing of fuel and (3) the cte of polymer composites containing a random dispersal of second phase near spherical particles. The silicon carbide in an irradiated coated particle exhibits selective corrosion at 1600 C. Solids loaded with gas bubbles exhibit cte values which are greater and less than that of the matrix material. The mathematical basis of a cylindrical fuel pin performance model is developed.