The Effect of Grain-level Creep Accommodation on Cavity Nucleation under Creep-fatigue Interaction

Nuclear power plants (NPPs) are used extensively as base load sources of electricity as this is the technically simplest mode of operation. However, for countries including the UK with a desire to increase renewable energy sources to create energy mix, the question arises as to whether the NPPs can be operated in a load-following mode. One can indeed assume that because of frequent load-following cycles, the capability to accurately predict the lifetime under creep-fatigue interaction is required. Our theoretical analysis showed that accelerated cavity nucleation occurred during creep dwells and this causes the life reduction. Neutron diffraction measurement will be used to validate the theoretical model prediction. The experiment-validated model will provide important data to support the life prediction of NPPs operating in a load-following mode on a regular basis.