Document: NRC Regulatory Guide
Document ID: 3c238fa7-baa2-41c1-ac85-868fcda6b038
Document Type: regulatory_guide
Title: Design Limits, Loading Combinations, Materials, Construction, and Testing of Concrete Containments + HISTORY – HISTORY 07/2020 – DG-1372 , Proposed Revision 4 05/2019 – Periodic Review of Revision 3 – Revise 10/2015 – Periodic Review of Revision 3 – Reviewed with issues identified for future consideration 10/2006 – DG-1159, Proposed Revision 3 Prior to the issuance of DG-1159, RG 1.136 was entitled "Materials, Construction, and Testing of Concrete Containments (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2010/ML20105A215.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.136
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CFR Title: 

Content:
ng the demonstration of containment structural integrity for accidents involving hydrogen release and combustible gas release, Regulatory Position 8.b provides loads and load combinations for pressure loads that result from a fuel-clad metal-water reaction, from an uncontrolled hydrogen burn, and from a post-accident condition inerted by carbon dioxide. The above requirements and guidance apply only to currently licensed reactors and future water-cooled reactor designs with characteristics (e.g., type and quantity of cladding materials) such that the potential for production of combustible gases is comparable to that of LWR designs licensed as of October 16, 2003. For nonwater-cooled reactors and water-cooled reactors that have different characteristics for the production of combustible gases from current LWRs (licensed as of October 16, 2003), the general DG-1372, Page 11 performance-based requirement in 10 CFR 50.44(d) needs to be addressed on a design-specific basis considering information on whether accidents involving combustible gases are technically relevant for their design depending on construction materials used. Regulatory Position 8.c indicates the staff position that use of Grade 75 and Grade 80 high-strength reinforcement allowed by the Code is not endorsed for general use for concrete containments. Research and development that integrates implications, including ductility, development length, and crack control, for the generic use of high-strength reinforcement is limited and still progressing. Furthermore, there is a lack of operating experience with high-strength reinforcement in the U.S. nuclear power industry and a lack of a precedent setting review in a licensing action for establishing a firm regulatory position for its generic use. However, the staff will review a proposed specific use of high-strength reinforcement and its supporting justification in a licensing action on a case-by-case basis. Regulatory Position 9 CC-3542: Loss of Prestress