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:
oop 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 to the outer cylindrical surface of the vessel by reinforcing bars extending radially inward from the precast channels. The strand is anchored at one end by means of a tapered wedge grip in the rib between adjacent channels and then wound around the vessel at the design tension for a number of turns and anchored in the next adjacent rib. Each band of circumferential prestressing consists of multiple layers of strand wound onto these channels. Each layer consists of one contin- *Lines indicate substantive changes from previous issue. uous length of strand. A maximum hoop prestressing force of about 6600 kips per linear, foot of vessel height was to have been used in the design of the PCRV head region of the Delmarva Summit Power Station.** The VSL strand system, which was developed in Switzerland, uses a wedge anchorage for strands. Each strand is drawn through the openings of both the bearing plate and the anchor head and is held by a two-piece split cone wedged tightly against the inner surface of the anchor head. As an example, the containment of the Rancho Seco Nuclear Generating Station in California uses the VSL system with tendons consisting of 55 strands, each tendon developing 2250 kips capacity. (The Freyssinet, SEEE, and VSL systems were formally presented as alternatives to the previously approved BBRV system. The VSL system was chosen by the applicant. Consequently, the Freyssinet and SEEE sys- tems were not reviewed by the NRC staff with regard to their acceptability for use in nuclear power plant containments.) The Stressteel S/H multistrand system, which was developed in the United States by Stressteel Corporation in cooperation with Howlett Machine Works, is charac- terized by a three-piece slotted wedge cone that grips three strands in its serrated