Author(s)

S.K. Wong, J. Caldwell & C.C. Chan

Abstract

Oxidation of nuclear reactor fuel cladding by steam: a moving boundary diffusion problem S.K. Wong/ J. Caldwell," C.C. Chan" "Department of Physics and Material Science, * Department of Mathematics,City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong ABSTRACT The oxidation of the zircaloy cladding of fuel rods in nuclear reactors, important during a severe accident, is governed by the diffusion of oxygen in solid zirconium. The latter exists in many phases which depend on the content of oxygen and have different diffusion coefficients. Discontinuous changes in oxygen concentrations occur at the phase boundaries, which also move in the course of diffusion, obeying an equation similar to the Stefan condition in heat transfer problems with phase change. We have devised and implemented a novel scheme for 1-D problems using the finite-difference approach, which involves setting the diffusion coefficient to zero in "forbidden" concentration ranges. The method i

Keywords