Document: NUREG-0800
Document ID: f9ea930a-8e7e-4e1f-b7a5-caeeffb721d5
Document Type: srp
Title: STEAM GENERATOR TUBE INSERVICE INSPECTION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070447.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.2.2
CFR Part: 
CFR Title: 

Content:
identified, and reporting requirements should follow the recommendations in the applicable Standard Technical Specifications. 3. Regulatory Guide RG 1.121 provides guidance on minimum acceptable tube wall thickness and describes a method acceptable to the staff for establishing the limiting safe conditions of degraded steam generator tubing, beyond which defective tubes, as established by inservice inspection, should be removed from service. The steam generator tube ISI program should be consistent with this guidance.22 Technical Rationale23 The technical rationale for application of the above stated acceptance criteria as required for steam generator tube inservice inspection programs is discussed in the following paragraphs. 1. General Design Criterion 32 requires, in part, that the design of all components which constitute the RCPB be such that inspection and direct examination of the pressure boundary is feasible, for purposes of assessing structural integrity and/or potential degra- dation. In terms of total surface area, the steam generator tubes in pressurized water reactor plants may comprise well over fifty percent of the area of the total pressure retaining boundary. Meeting General Design Criterion 32 assures that an effective periodic inspection program can be performed, so that steam generator tube degradation can be identified and preventive measures promptly implemented to assure the integrity of the RCPB. 2. 10 CFR 50.55a, "Codes and Standards" incorporates Section XI of the ASME Code by reference and thereby establishes the applicability of Code requirements for ISI programs. The Code defines, for each ASME Code Class, the time interval for the inspection, the scope of the inspection activity, the inspection sample, sample selection DRAFT Rev. 2 - April 1996 5.4.2.2-4 methodology, the method of inspection, the acceptance criteria for various types and sizes of flaws identified during the inspection, and various other related technical details