Document: NUREG-0800
Document ID: 85a8d3b1-a30b-4282-8217-8bc68986145a
Document Type: srp
Title: ASME CODE CLASS 1, 2, AND 3 PIPING SYSTEMS, PIPING COMPONENTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1404/ML14042A513.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.12
CFR Part: 
CFR Title: 

Content:
” Section 3.1.1.2. Appendix S to 10 CFR Part 50, “Earthquake Engineering Criteria for Nuclear Power Plants,” first issued in 1996 and revised in 2007, implements Commission policy related to the use of OBE ground motion for applications submitted after January 10, 1997. If the OBE is defined as greater than one-third of the SSE, paragraph IV.(a)(2) requires analysis and design to demonstrate that SSCs remain functional and within applicable stress, strain, and deformation limits. Loads from the OBE, 3.12-11 Revision 1 – April 2014 therefore, would be included in the piping stress analysis. If the OBE is defined as one-third or less of the SSE, explicit response or design analyses are not required. xv. Welded Attachments Support members, connections, or attachments welded to piping should be designed such that their failure under unanticipated loads does not cause failure at the pipe pressure boundary. The applicant may use Code Cases for the design of the welded attachments. Acceptable Code Cases are listed in RG 1.84. xvi. Modal Damping for Composite Structures The acceptance criteria provided in SRP Section 3.7.2, Subsection II.13 are applicable. xvii. Temperature for Thermal Analyses The stress-free reference temperature for a piping system should be defined as 70°F. For piping systems that operate at temperatures above 70°F, a thermal expansion analysis should be performed in accordance with ASME Section III. If thermal expansion analyses are not performed for such systems (i.e., a higher stress-free reference temperature is selected), the applicant should justify the higher temperature. The justification will be reviewed on a case by case basis to confirm that this higher temperature is suitable for the piping configuration, design support loads, piping displacement, etc.. xviii. Intersystem LOCA In SECY-90-016, “Evolutionary Light Water Reactor (LWR) Certification Issues and Their Relationship to Current Regulatory Requirements,” dated January 2,