Document: NRC Regulatory Guide
Document ID: 91c1459d-4ae6-4802-8c6d-e805db860e10
Document Type: regulatory_guide
Title: Post-tensioned Prestressing Systems for Concrete Reactor and Containment (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1221/ML12216A010.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.103
CFR Part: 
CFR Title: 

Content:
em being discussed and provide a reference to some plants for which the systems in Table A have been proposed or approved. The examples cited are not intended to indicate any restric- USNRC REGULATORY GUIDES tion or preference in size of the tendon for a given system. Nor is this guide intended to discourage the development of refinements of current systems or the development of new prestressing systems or concepts. The qualifications that a post-tensioned prestressing system should meet in order to be' acceptable to the NRC staff are identified in the regulatory position. Rock anchorage systems are not covered by this guide. Types of Systems The type of tendon selected usually dictates the choice of stressing equipment and also affects the choice oi end anchorages. Basically, post-tensioned prestressing systems can be separated into three general categories according to the types of tendon in use: wire, strand, and bar systems. End anchorages for these tendons are based on either wedge or direct-bearing principles; sometimes a combina- tion of the two is used. Post-tensioned prestressing systems are described below in terms of types of tendons and end anchorages. Wire Systems. Wire systems use a number of parallel wires grouped to form a tendon. Wires manufactured in the United States conform to ASTM Specification A-421, "Uncoated Stress-Relieved Wire for Prestressed Concrete."'l This specification provides for wires of two types (BA or WA), depending on whether they are to be used with buttons or wedge anchorages. The BBRV system, developed in Switzerland by Birkenmaier, Brandestini, Ros, and Vogt, is a wire system used in both concrete reactor vessels and *Copies of this and other ASTM specifications referenced in this guide may be obtained from the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103. Comments should be gent to the Secretary of the Commission. U.S. Nuclear Regulatory Guides awe issued to describe and