Document: NUREG-0800
Document ID: 3d8f7691-e488-4083-af2f-eef689c0ec98
Document Type: srp
Title: ASME CODE CLASS 1, 2, AND 3 COMPONENTS AND COMPONENT SUPPORTS,
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0704/ML070430397.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.3
CFR Part: 
CFR Title: 

Content:
stress limits. B. The combination of design and service loadings, including procedures for combination, proposed by the applicant for each Code-constructed item, are reviewed to determine if they are adequate. This aspect of the review is made by comparison with the loading combinations and procedures for combination set forth in Appendix A. Deviations from the position are evaluated on a case-by-case basis by questions addressed to the applicant to determine the rationale and justification for exceptions. A final determination is based on engineering judgment and agency experience with prior applications. C. The design and service stress limits selected by the applicant for each set of design and service loading combinations are reviewed to determine if they meet those specified in Appendix A. The criteria to ensure piping component functional capability are reviewed to determine their adequacy in meeting the objectives set forth in Appendix A. Deviations from the position may be permitted provided justification is presented by the applicant. The acceptability determination is based on considerations of adequate margins of safety. In the ABWR and System 80+ design certification Final Safety Evaluation Reports the staff accepted an exemption to 10 CFR Part 100, Appendix A requiring that all safety- related SSCs be designed to remain functional and within applicable stress and deformation limits when subjected to an operating basis earthquake(OBE). Acceptance of the exemption was predicated on the use of an alternative seismic analysis based entirely on the Safe Shutdown Earthquake (SSE) and implementation of additional procedural requirements relating to a seismic event, in accordance with 10 CFR Part 50, Appendix S. The staff's evaluation of Code Class 1, 2, and 3 components and core support structures ensured that appropriate measures and adequate safety margins were maintained when the OBE was eliminated from design. 2. Design and Installation of Pressure Relief