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:
, and slag conductivity, have been shown to influence the weld solidification pattern. If the combination of process variables produces a deep pool of molten weld metal, the crystal (dendritic) growth direction from the pool sides will join at an obtuse angle at the center of the weld, and cracks may develop because of the weaker centerline bond between dendrites. A proper combination of process variables promotes a dendritic growth pattern with an acute joining angle, which results in a strong centerline bond. The welding variables, solidification patterns, and macro etch tests used in the electroslag welding of austenitic stainless steel are reviewed. Experience has shown that a welder qualified to weld stainless steel components under normal fabricating conditions may not produce acceptable welds if the accessibility to the weld area is restricted. Limited accessibility can occur when component parts are joined in the final assembly or at the plant site, where other adjacent components or structures prevent the welder from assuming an advantageous position during the welding operation. The adequacy of accessibility of field erected structures, for welding austenitic stainless steel components, is reviewed. E. The requirements for nondestructive examination of wrought seamless tubular products used for components of nuclear power plants are specified in Paragraphs NB-2550 through NB-2570 of the Code, Section III. Nondestructive examination techniques applied to tubular products used for components of the RCPB, or other safety-related ASME Class 1 systems that are designed for pressure in excess of 1.896 MPa (275 psig) or temperatures in excess of 93EC (200EF), must be capable of detecting unacceptable defects regardless of defect shape, orientation, or location in the product. The nondestructive examination procedures used for inspection of tubular products are reviewed. F. Where cast austenitic stainless steel components are proposed for use in the RCPB, the