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
CFR Part: 
CFR Title: 

Content:
Type 2. The criterion for Type 1 mechanical splices is that a mechanical splice shall develop no less than 125 percent of the specified minimum yield strength of the spliced bar, as stated in Section 12.14.3.2 of the Code Case. Type 1 mechanical splices are not allowed to be used in regions that may experience steel yielding. The criterion for Type 2 mechanical splices is that a mechanical splice shall develop the specified tensile strength of the spliced bar, as stated in Section 21.1.6.1 of the Code Case. The specified or actual tensile strength of the steel reinforcing bars is used to calculate the ultimate capacity of concrete containment structures against the internal pressure as a measure of the safety margin above the design-basis accident pressure. Consequently, Type 2 mechanical splices must be used in concrete containment structures. Therefore, the criterion in Section 2.3 of Code Case N-791 is the equivalent criterion for Type 1 mechanical splices of ACI Standard 318, which is not an adequate criterion for qualifying mechanical splices for use in concrete containment structures. Additionally, the strength criterion in the Code Case does not address the additional conditions for the reinforcing bar specified in ASTM A706 and CC-2231.2, which place an upper limit on the actual yield strength and require the ratio of actual tensile strength to actual yield strength to be not less than 1.25. Therefore, the Code Case should develop a more stringent strength criterion for splice qualification, and the same criterion should also be used for continuing splice performance tests in the field, as stated in Section 5 of the Code Case. N-793 Extruded Steel Sleeves with Parallel Threaded Ends, Section III, Division 2 See comments for Code Case N-791. 9/20/10 N-794 Swaged Splice with Threaded Ends, Section III, Division 2 See comments for Code Case N-791. 9/20/10 N-796 Threaded Sleeves with Parallel Threads Cut on Upsized Bar Ends, Section III, Division 2 See comments