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:
the injection pressure was very high (twice the pressure used during installation of grease), the amount of grease replaced was 10 to 15% higher than that removed. The staff discourages this practice, as there is a likelihood of tearing the sheathing joints at such pressures, opening a way for grease to seep into the concrete. Hence, Regulatory Position 7.4 has been revised to reflect this consid eration. The NRC staff encourages operating plant licen sees to review their existing tendon inservice inspec tion programs and evaluate them from the standpoint of operating convenience, safety improvements, and cost reduction potential. The NRC staff recognizes that in some older plants (plants operating before the initial issuance of Regulatory Guide 1.35 in 1974), adopting all provi sions of this revised guide may not be feasible without extensive retrofitting. In such cases, licensees are ad vised to present their revised inservice inspection pro grams with any necessary exemptions from the 1.35-2 specific provisions of this guide. If licensees adopt this Revision 3 to Regulatory Guide 1.35, it should be adopted in its entirety, not just segments of the guide. C. REGULATORY POSITION 1. GENERAL 1.1. The inservice inspection program de scribed in this guide should be used with the following types of prestressed concrete containment structures: a. Prestressed concrete containments having a shallow-dome roof on cylindrical walls with the cylinder prestressed in hoop and vertical direc tions and the dome prestressed by three families of tendons at 600. b. Prestressed concrete containments having a hemispherical-dome roof on cylindrical walls with two families of inverted U tendons placed at 900 to each other and hoop tendons located in the cylin der and dome. 1.2. For containments that differ from these two types, the program described should serve as the basis for the development of a comparable inservice inspection program. 1.3. The inservice inspection should be per