Irradiation-Induced Deformation of Zircaloy-2 Calandria Tubes in CANDU Reactors

Abstract

Under normal power reactor operating conditions irradiation-induced dimensional changes in the Zircaloy-2 calandria tubes are very difficult and in most cases impossible to measure. Hence, the equations describing the irradiation-induced creep (strain in response to an applied stress) and growth (strain in the absence of any applied stress), used to predict the behaviour with time and design the fuel channels in new, improved reactors have been derived from experiments in research reactors. The current equation provides a good description of the creep behaviour but not the growth behaviour. The development of an updated equation utilizing recent experimental results and improved analytical and theoretical understanding are described.