Document: NRC Regulatory Guide
Document ID: 4a45938b-46f4-4b26-9191-2914fcf357f1
Document Type: regulatory_guide
Title: Inservice Inspection of Pressurized Water Reactor Steam Generator Tubes (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740256.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.83
CFR Part: 
CFR Title: 

Content:
econdary leaks exceeding technical specifications, a seismic occurrence greater than an operating basis earthquake,2 a loss-of-coolant accident requiring actuation of engineered safeguards, or a major steam line or feedwater line break. 7. Acceptance Limits a. As used in this regulatory guide: (1) Imperfection means an exception to the dimensions, finish, or contour required by drawing or specification. (2) Defect means an imperfection of such seventy that the tube is unacceptable for continued service. (3) Bugging limit means the imperfection depth at or beyond which plugging of the tube must be performed. (Note that the plugging limit is not a depth of penetration within the defect range but rather an imperfection depth with conservative allowances. These allowances include such considerations as general corro sion and measurement error.) (4) Plugging criteria means those calculational and analytical procedures used to arrive at the plugging limit. These currently may be submitted by a licensee for approval by NRC. b. If, in the inspection performed under regula tory position CA, less than 10% of the tubes inspected have detectable wall pentration (>20%) and no tube has imperfections that exceed the plugging limit defect, plant operation may resume. 'Copies may be obtained from the American Society of Mechanical Engineers, United Engineering Center, 345 East 47th Street, New York, New York 10017. 1.834 I c. If, in the inspections performed under regula tory position C.5, less than 10% of the total tubes inspected have detectable wall penetration (>20%) and no more than three tubes exceed the plugging limit, plant operation may resume after required corrective measures have been taken. d. If, in the inspections performed under regula tory position C.5, more than 10% of the total tubes inspected have detectable wall penetration (>20%) or more than three of the tubes inspected exceed the plugging limit, the situation should be immediately reported to the Commission