Notch Ductility and Tensile Property Evaluation of the Pm-2A Reactor Pressure Vessel

摘要

Following the pressurization-to-failure testing of the PM-2A reactor pressure vessel, several sections of steel were removed from the vessel wall in a region adjacent to the artificial defect. Charpy V-notch and tension test specimens machined from one of these sections have been evaluated. The irradiated-condition 30 ft-lb transition temperatures for the 1/4-thickness (nearest to the core) and 3/4-thickness locations in the vessel wall were +115F and +55F, respectively, for measured fission-spectrum fluences of 7.3 and 4.0 X 10 to the 18th power n/sq cm (greater than 1 Mev). The 1/4-thickness properties and fluence most nearly represented those at the tip of the artificial defect. The 0.2% yield strength for the 1/4-thickness location was 97,620 psi at -20F (failure temperature) and 92,200 psi at +72F (temperature at time of acid-sharpening treatment of artificial defect). Significant uniform elongation, reduction of area, and elongation per 1 in. were retained by the steel. An assessment of the stress, temperature, and flaw-size conditions for the PM-2A failure, as indexed by the irradiated-condition mechanical properties, indicates that the failure is in agreement with the generalized fracture analysis diagram. (Author)