Document: NRC Regulatory Guide
Document ID: 47283fef-08ff-4021-afa3-0c8370080b94
Document Type: regulatory_guide
Title: Inservice Inspection of ASME Code Class 2 and 3 Nuclear Power Plants components
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1335/ML13350A361.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.51
CFR Part: 
CFR Title: 

Content:
onents classified as AEC Quality Group A. B, and C should conform to the requirements of the ASSlI' Boiler and Pressure Vessel Code for Class I. 2. and 3 components, resp ctively. TER PLANT COMPONENTS componen ts. In the Winter 1972 Addenda to Section XI, 3 acceptable inservice inspection requirements are specified for Code Class 22 components. Code Class 32 components are not presently included in Section X1 requirements, but they should also be part of the scheduled inservice inspection program. The inspection requirements need not be as extensive as those required for Code Class 2 components but should, as a minimum. include visual inspection of Code Class 3 componentb and their supports. For such inspections to be effective. they should be performed at periods when the components are under pressure of sutficienti nagnitude to properly represent the intended service condition. This may require that the inspections of Code Class ' components be scheduled to coincide with system performance tests, component functional tests, and system pressure tests in order to benefit from the pressure levels established for these tests. Section XI defines an inspection interval for Code Class I and 2 components as 10 years, and the inservice inspection program for Code Class 3 components should be based on the same time interval. Code Class 3 components required to function during normal reactor operation would generally he accessible during reactor downtime, and they should be inspected at least once toward the end ot each inspection interval. Components in systems or portiovri of systems which are not required to futiction during reactor operation can be inspected independently of reactor downtime. The visual inspection of Code Class 3 components should be conducted for signs or evidence of leak.:'c caused by structural distress or corrosion effects on the, components. In addition, supports and hangers lilt piping and Code Class 3 componenls over 4 inches ill dianicter should