Document: NUREG-0800
Document ID: 6cdd237d-c5b3-4a09-8753-54cfe1fea503
Document Type: srp
Title: REACTOR VESSEL MATERIALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190007.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.3.1
CFR Part: 
CFR Title: 

Content:
to contain reactor coolant inventory, reduction in capability to confine fission products, or interference with core cooling. 4. GDC 31 and 10 CFR 50.55a establish fracture toughness requirements and the applicable ASME standards respectively. GDC 31 establishes that the RCPB be designed with sufficient margin to assure that when stressed under operating, maintenance, testing, and postulated accident conditions (1) the boundary behaves in a non-brittle manner and (2) the probability of rapidly propagating fracture is minimized. 10 CFR 50.55a incorporates the applicable editions and addenda of the ASME Boiler and Pressure Vessel Code that are relevant to the fracture toughness requirements of GDC 31 and 10 CFR Part 50, Appendix G. The design is required to reflect consideration of service temperatures and other conditions of the boundary material under operating, maintenance, testing, and postulated accident conditions and the uncertainties in determining (1) material properties, (2) the effects of irradiation on material properties, (3) residual, steady state, and transient stresses, and (4) the size of flaws. The reactor vessel is an integral part of the RCPB and is fabricated of thick section materials subjected to stresses including those from full reactor coolant pressure and thermal gradients. Application of GDC 31 to the reactor vessel materials assures that they are selected to provide sufficient design margin to account for uncertainties associated with flaws and the effects of service and operating conditions, and thereby to provide a minimum probability of material degradation leading to rapid failure of the vessel and loss of reactor coolant. 5. GDC 32 requires that RCPB components shall be designed to allow periodic inspection and testing to assess their structural and leak-tight integrity, and a material surveillance program for the reactor pressure vessel. The reactor vessel material surveillance program monitors the reactor vessel belt-line materials