Document: NRC Regulatory Guide
Document ID: 0b9a3243-ab39-402c-9f4b-215c6e4f79ab
Document Type: regulatory_guide
Title: Inservice Inspection of Ungrouted Tendons in Prestressed Concrete Containments (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740007.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.35
CFR Part: 
CFR Title: 

Content:
quent inspection with a minimum of three tendons for each group. 2.3. The fraction obtained as a percentage of a tendon population should be rounded off to the near est integer. 2.4. The tendons to be inspected should be randomly selected from each group during each in spection. However, to develop a history and to corre late the observed data, one tendon from each group should be kept unchanged after the initial selection, and these unchanged tendons should b.e identified as control tendons. 2.5. If, owing to plant operating conditions, a randomly selected tendon from a group cannot be inspected during a scheduled inspection, another sample from the group should be randomly selected. The tendon that was selected but not inspected should be inspected during the following plant shut down and accepted (or rejected) on an individual tendon basis. 2.6. Tendons, except the control tendons, that had been inspected and found intact during previous inspections should be excluded from the group popu lation during subsequent inspections. 3. VISUAL INSPECTION 3.1. The exterior surface of the containment should be visually examined to detect areas of large spall,3 severe scaling, D-cracking in an area of 25 square feet or more, other surface deterioration or disintegration, or grease leakage. 3.2. Tendon anchorage assembly hardware (such as bearing plates, stressing washers, shims, wedges, and buttonheads) of all tendons selected as described in Regulatory Position 2 should be visually examined. For those containments for which only vis ual inspections need be performed, tendons selected as described in Regulatory Position 2 should be visu ally examined to the extent practical without disman tling load-bearing components of the anchorage or removing grease caps. 3.3. Bottom grease caps of all vertical tendons should be visually inspected to detect grease leakage or grease cap deformations. Removal of grease caps is not necessary for this inspection. 3The terms "large spall,"