Document: NUREG-0800
Document ID: e708512f-f35c-453e-9fc1-354ab0bf12ad
Document Type: srp
Title: STEEL CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550050.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.8.2
CFR Part: 
CFR Title: 

Content:
d Materials Code Case Acceptability, ASME Section III” and RG 1.193, “ Code cases not approved for Use,” provide additional guidance for code case acceptability which should be considered in the design of steel containments. Any Code cases not currently approved by NRC requires review on a case by case basis. C. Computer Programs The computer programs used in the design and analysis should be described and validated by procedures or criteria described in Subsection II.4.e of SRP Section 3.8.1. D. Ultimate Capacity of Steel Containment For new reactors, regulatory criteria require a determination of the internal pressure capacity for containment structures, as a measure of the safety margin above the design-basis accident pressure. One methodology acceptable to the staff for cylindrical steel containments is to estimate the capacity based on attaining a maximum global membrane strain away from discontinuities (i.e., the hoop membrane strain in a cylinder) of 1.5 percent. To conduct the necessary analysis, both nonlinear material behavior and nonlinear geometric behavior must be considered. The stress-strain curve for the steel containment material should be based on the code-specified minimum yield strength and a stress-strain relationship above yield that is representative of that specific grade of steel. The stress-strain curve must be developed for the design-basis accident temperature. Analyses of noncylindrical containments and analyses of cylindrical containments that use alternate failure criteria will be subject to detailed staff review, on a case-by-case basis. 3.8.2-18 Revision 2 - March 2007 The NRC has published guidance on computer modeling of steel containments for internal pressure capacity calculations in NUREG/CR-6906. Note: In applying the analysis methodology to existing containment structures, it is permissible to use as-built material properties for the steel containment material. Sufficient material certification data must be available to