Irradiation Behaviors of Nuclear Grade Graphite in Commercial Reactor, (II) Thermal and Physical Properties

Abstract

Thermal conductivity, electrical resistivity and stored energy were measured for Pechiney nuclear grade graphite irradiated in the temperature range 220--400°C up to the maximum neutron fluence 2 . 2~ 1O2O n/cm2(E>0.85 MeV) in the environment of a carbon dioxide in a commercial reactor. Thermal conductivity decreased, electrical resistivity and stored energy increased owing to neutron irradiation and their changes were larger for the samples irradiated a t lower temperatures.A linear relation between stored energy and fractional change in thermal resistivity was obtained for the irradiated samples and it was found that its proportional constant is about two times of that reported previously. The relation between thermal conductivity and electrical resistivity is discussed for irradiated samples as well.

Influence of H+ ion irradiation on the surface and microstructural changes of a nuclear graphite

“…In a fusion environment, rigorous conditions such as fast neutron irradiation and thermal shock give rise to diverse changes in micro-/surface structures and physical/mechanical properties including bulk density, coefficient of thermal expansion, thermal conductivity, Young's modulus, and Poisson's ratio [5][6][7][8]. Indeed, Theodosiou et al showed a reduction of crystalline size by ion irradiation [9], and Chi et al observed an increased porosity of graphite after 3 MeV C + ion irradiation [10].…”