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:
CRV) of the Fort St. Vrain station in Colorado uses the BBRV system with 169-wire tendons developing approximately 2000 kips capacity each. A number of containments using the BBRV system with 90, 163, 169, 170, and 186 wires per tendon have been built in the United States. The wire diameter is 1/4 inch (6.35 mm) in all cases except for the 163-wire tendon, which uses 7-mm (0.28 inch) wire. A wire-winding system was used to provide hoop prestress for the Hartlepool PCRVs in England. This method of providing hoop prestress is similar to that for conventional prestressed concrete tanks. Strand Systems. Strand systems use a number of "strands" that are bundled into a tendon. A strand is made up of a number of factory-twisted wires. Stress- relieved strand is made in two forms. The first is the seven-wire strand, which conforms to ASTM Specifica- tion A-416, "Uncoated Seven-Wire Stress-Relieved Strand for Prestressed Concrete." The second form consists of larger strands that are made of larger individual wires and may consist of more than seven wires per strand. The larger strands are not covered by ASTM specifications and have not been used for the construction of nuclear power plants in the United States. Strand systems have been introduced in the construc- tion of nuclear power plants by Strand-Wrap, VSL, (Vorspann System Losinger), Stressteel, Freyssinet, and SEEE (Societe d'Etudes et d'Equipements d'Enter- prises). The last two systems were considered but have not yet been used in the United States in nuclear power plants. Both the Freyssinet and SEEE systems have been used in Europe on concrete reactor vessels. The Strand-Wrap system has been reviewed and approved only for applying hoop prestressing to some PCRVs in the United States. The basic principles of applying hoop prestressing to the PCRV by the Strand- Wrap system are the same as those of a wire-winding system. In one of the design methods, steel-lined circumferential precast concrete channels are anchored