Unirradiated material properties of Midland weld WF-70

Abstract

Weld metal, designated WF-70, taken from the nozzle course and beltline welds of the Midland Reactor, Unit 1, has been given a preliminary evaluation using the conventional Charpy V-notch (CVN), drop-weight (DWT), and chemical analyses. These tests indicated essentially identical fracture toughness at both locations, but there was a significant deference in copper content, nominally 0.25% versus 0.40%. Because the objective of this study was to evaluate the before-and-after irradiation properties, these are regarded as different materials. This report summarizes material characterization results and presents the results of fracture mechanics tests on the unirradiated material to establish baseline transition temperature and J-R curves. Tensile properties were also determined. Five experimental objectives to be accomplished from the testing of irradiated materials were identified. One of the more important objectives is to improve the precision of transition temperature shift and to identify any curve shape changes after irradiation, concentrating on utilizing data from small surveillance capsule size specimens.