Mechanical Property Changes Related to Through-Wall Attenuation of Neutron Irradiation Embrittlement Available to Purchase

The through-wall attenuation of neutron fluence of reactor pressure vessel (RPV) steels is often expressed using an exponential decay function based on some estimate of displacements per atom (dpa). In order to verify this function, an irradiation project was performed in which 18 layers of Charpy specimens and one central temperature control layer were stacked in a block to simulate a 190 mm thick RPV wall. Three western-type RPV steels (medium and low copper plates and a high copper Linde 80 flux weld) were irradiated in this project. Mechanical property tests of these materials have been performed under a consortium of EPRI, CRIEPI, NRI-Rez and ATI Consulting to fully characterize the mechanical properties in terms of Charpy transition temperature and upper-shelf energy, as well as reference fracture toughness using the Master Curve. These results have been published and presented previously. Recent hardness measurements were made on the three materials at various thickness levels and the results are summarized in this paper and compared to the previous mechanical property results. This paper has a related paper on microstructure characterization of these same irradiated materials at different thickness levels.