Document: NUREG-0800
Document ID: d8b522d4-dee5-4122-89d4-b2b45d0ca729
Document Type: srp
Title: REACTOR COOLANT PRESSURE BOUNDARY MATERIALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070420.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.2.3
CFR Part: 
CFR Title: 

Content:
nitic stainless steels in any condition in boiling water reactors (BWR's) requires special attention because of the oxygen content of BWR 8 coolant. 3. Fabrication and Processing of Ferritic Materials Items 3.a, 3.b, and 3.c are reviewed by MTEB.9 a. The fracture toughness properties of ferritic materials used for pressure-retaining components of the reactor coolant pressure boundary are reviewed. The fracture toughness tests performed on all ferritic materials used for pressure-retaining RCPB components (i.e., vessels, pumps, valves, and piping) are reviewed. The test procedures used for Charpy V-notch impact and dropweight testing are reviewed. Fracture toughness of the material is characterized by its reference temperature, RT . This temperature is the higher of the nil ductility temperature (NDT) NDT from the dropweight test or the temperature that is 33.5 C (60 F) below the 10 temperature at which Charpy V-notch impact test data are 68 J (50 ft-lbs) and 11 0.89 mm (35 mils) lateral expansion. 12 13 b. The control of welding in ferritic steels is reviewed. (1) The quality of welds in low alloy steels can be increased significantly by proper controls. In particular, the propensity for cold cracks or reheat cracks to form in areas under the bead and in heat-affected zones (HAZ) can be minimized by maintaining proper preheat temperatures of the base metal concurrent with controls on other welding variables. The minimum preheat temperature and the maximum interpass temperatures are reviewed. (2) The quality of electroslag welds in low alloy steel components can be increased by maintaining a weld solidification pattern that possesses a strong intergranular bond in the center of the weld. The welding 5.2.3-3 DRAFT Rev. 3 - April 1996 variables, which have a significant effect on the weld solidification pattern, must be controlled. The welding variables, solidification patterns, macro etch tests, and Charpy V-notch impact tests of electroslag welds are reviewed. It