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:
the appropriate combination of loadings resulting from (1) sustained loads, (2) specified plant/system operating transients (SOT), and (3) the OBE. Exemptions that have been permitted from regulatory requirements to use OBE and the acceptable alternative to use of OBE in the design of components, component supports, and core support structures are described in Subsection III.1 of this SRP section. (iii) Service Limit C. (1) Code Class 1, 2, and 3 components, component supports, and core support structures shall meet a service limit not greater than Level C when subjected to the appropriate combination of loadings resulting from (1) sustained loads, and (2) the DBPB. 3.9.3-21 Revision 2 - March 2007 (2) The DBPB includes loads from the postulated pipe break, itself, and also any associated system transients or dynamic effects resulting from the postulated pipe break. (iv) Service Limit D. (1) Code Class 1, 2, and 3 components, component supports, and core support structures shall meet a service stress limit not greater than Level D when subjected to the appropriate combination of loadings resulting from (1) sustained loads, (2) either the DBPB, MS/FWPB, or LOCA, and (3) and SSE. (2) The DBPB, MS/FWPB, and LOCA include loads from the postulated pipe breaks, themselves, and also any associated system transients or dynamic effects resulting from the postulated pipe breaks. Asymmetric blowdown loads on PWR primary systems should be incorporated per NUREG-0609. 5. OPERABILITY AND FUNCTIONAL CAPABILITY A. Active Pumps and Valves. SRP Section 3.10 provides guidance to reviewers to ensure that applicants demonstrate that pumps or valves, as supported, can adequately sustain the designated combined service loadings at a stress level bounded by the specified service limit. Stresses in valve bodies and pump casings should be limited to the particular material’s elastic limit when the pump or valve is subjected to the combination of normal operating loads, SSE and other