Neutron-Irradiated Microstructure of Light Water Reactor Materials

The safe, long-term operation of light water reactors for power generation can be limited by irradiation-induced aging of the materials, which is manifested in the microstructure via a number of phenomena.  Analytical scanning transmission electron microscopy is a powerful tool for investigating the manifestation of neutron-irradiation on materials.  This talk will give an overview of irradiation-induced microstructural phenomena present in austenitic stainless steel reactor pressure vessel internals materials, by utilizing examples from various materials at different dose levels from different reactor components.  They include examples from bolts, plates, and thimble tubes, with neutron irradiation levels from 2.9 dpa up to 100 dpa, which have been examined at VTT by analytical transmission electron microscopy.