An Evaluation of the Effect of Radiation Environment on Linde 80 Reactor Vessel Welds

The B&W Owners Group (B&WOG) developed the Master Integrated Reactor Vessel Surveillance Program (MIRVP) to encompass all domestic operating pressurized water reactors (PWRs) with reactor vessels that contain Linde 80 submerged-arc welds. These PWRs include the reactor vessels fabricated by Babcock & Wilcox (B&W) that include B&W-designed 177-Fuel Assembly (FA) plants and Westinghouse-designed plants. The B&WOG Reactor Vessel Working Group has sponsored studies over the past several years to develop an understanding of the mechanisms and trends of radiation embrittlement for reactor vessel submerged-arc welds fabricated using Linde 80 weld flux. As part of the MIRVP, a Westinghouse-designed capsule was included to provide a comparison of irradiation data in the Westinghouse neutronic environment with the B&W 177-FA environment. This paper presents the effect of irradiation environment on the embrittlement trends of Linde 80 submerged-arc welds based on mechanical test data available through the B&WOG and the literature, and existing trend curves.