Document: NUREG-0800
Document ID: a2f24e8d-bc9b-4cc9-91c8-556b80541349
Document Type: srp
Title: SPECIAL TOPICS FOR MECHANICAL COMPONENTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0704/ML070430402.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.1
CFR Part: 
CFR Title: 

Content:
nd the number of load and stress cycles per event and for events in combination should be included. All transients, such as startup and shutdown operations, power level changes, emergency and recovery conditions (including, for new applications, natural convection cooldown), switching operations (i.e., startup or shutdown of one or more coolant loops), control system or other system malfunctions, component malfunctions, transients from single operator errors, inservice hydrostatic tests, seismic events as determined from the criteria specified in Appendix S to 10 CFR Part 50, and design-basis events contained in the Code-required "Design Specifications" for the components of the reactor coolant pressure boundary, should be specified. The section of the applicant's SAR on transients will be acceptable if the transient conditions selected for equipment fatigue evaluation are based upon a conservative estimate of the magnitude and frequency of the temperature and pressure conditions caused by those transients. To a large extent the selection of these specific transient conditions is based upon engineering judgment and experience. Some guidance on the selection of these transients and combinations can be found in SRP Section 3.9.3. Transients and consequent loads and load combinations with appropriate specified design and service limits should provide a complete basis for design of the reactor coolant pressure boundary for all conditions and events expected over the service lifetime of the plant. The staff should consider the number of transients appropriate for the design life of the plant. Also, environmental conditions to which equipment important to safety will be exposed (e.g., chemistry of the coolant water) should be considered to minimize the degradation of materials due to corrosion. 2. To meet the requirements of 10 CFR Part 50, Appendix B, and GDC 1, a list of computer programs to be used in dynamic and static analyses to determine the structural and