PNNL

Abstract

Measurements are presented of electrical resistance and elastic moduli (Young’s modulus and shear modulus) of stabilized austenitic fuel pin cladding after irradiation in the BN-600 reactor. Additional data are presented on changes in electrical resistivity of another stabilized austenitic steel irradiated in the BN-350. The elastic moduli are reduced and the electrical resistance is increased as the neutron dose increases. Dependencies of these changes in physical properties on neutron irradiation dose, temperature, and swelling level are plotted and it is shown that to the first order, the property changes are dependent on the swelling level, in agreement with earlier U.S. and Russian data. It is also observed, however, that changes in electrical resistance and elastic moduli frequently differ slightly for specimens with equal swelling, but which were obtained at different combinations of temperature and dose. These second-order differences appear to arise from contributions of other radiation-induced structural changes, especially in precipitation, which depends strongly on irradiation temperature in these stabilized steels.