Significance and Assessment of Low Temperature Creep and Irradiation Creep in Nuclear Reactor Applications

Abstract

The mechanisms and characteristics of low temperature creep and irradiation creep of structural alloys in light water reactor service are briefly reviewed. The significance of creep is made clear in relation to the environmentally-assisted cracking (EAC). It is shown that while total creep itself may not be significant the attendant slow strain rates are likely contributors critical to the manifestation of EAC. This interrelation of the creep and EAC is further assessed with validation of a continuum damage mechanics approach to quantify the EAC kinetics. Limitations of the formulation and other approaches are discussed, with a note that the influence of irradiation creep on EAC appears not to have been taken into account at present. These aspects are discussed identifying possible useful refinements in assessing the role of creep in EAC.