Irradiation growth of zirconium alloy nuclear reactor structural components

Irradiation growth, which is defined as irradiationinduced changes in dimensions in the absence of an applied stress, is of concern both for fuel cladding and nuclear reactor structural components such as pressure tubes and calandria tubes. A critical review is presented of irradiation growth data for zirconium alloys together with a discussion of the various operating and material factors affecting growth. Empirical and mechanistic models used to explain and predict irradiation growth are reviewed and the most applicable are identified. On the basis of the data presented, implications are drawn with respect to the optimum fabrication procedures and material characteristics of zirconium alloys used for structural components in nuclear reactors.