Document: NUREG-0800
Document ID: 4a46b35d-2e81-4517-9716-154b19f57049
Document Type: srp
Title: REACTOR COOLANT PRESSURE BOUNDARY MATERIALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190006.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.2.3
CFR Part: 
CFR Title: 

Content:
RP Sections 5.4.8 and 9.3.4. The organization responsible for chemical engineering issues also reviews the compatibility of the materials of construction employed in the RCPB with the reactor coolant, contaminants, or radiolytic products to which the system is exposed. The extent of the corrosion of ferritic low alloy steels and carbon steels in contact with the reactor coolant is reviewed. Similarly, the primary review organization reviews possible uses of austenitic stainless steels in the sensitized condition and nickel-chromium-iron alloys. The use of austenitic stainless steels in any condition in boiling water reactors (BWRs) requires special attention because of the oxygen content of BWR coolant. The use of nickel-chromium-iron alloys in the RCPB of pressurized water reactors (PWRs) requires attention due to primary water stress corrosion cracking of certain nickel-chromium-iron alloys. 3. Fabrication and Processing of Ferritic Materials 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, RTNDT. This temperature is the higher of the nil ductility temperature (NDT) from the dropweight test or the temperature that is 33EC (60EF) below the temperature at which Charpy V-notch impact test data are 68 J (50 ft-lbs) and 0.89 mm (35 mils) lateral expansion. 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