Document: NUREG-0800
Document ID: 1385efd4-bcc7-4d91-9a98-cb58d888fb24
Document Type: srp
Title: -6
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1233/ML12334A360.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.9.3
CFR Part: 
CFR Title: 

Content:
Draft Revision 3 – June 2013 2. Design and Installation of Pressure Relief Devices. The applicant should use design criteria for pressure relief installations specified in Appendix O, ASME Code, Section III, Division 1, "Rules for the Design of Safety Valve Installations.” In addition, the following criteria are applicable: A. Where more than one valve is installed on the same pipe run, the sequence of valve openings to be assumed in analyzing for the stress at any piping location should be that sequence which is estimated to induce the maximum instantaneous value of stress at that location. B. Stresses should be evaluated, and applicable stress limits should be satisfied for all components of the pipe run and connecting systems and the pressure relief valve station, including supports and all connecting welds between these components. C. In meeting the stress limit requirements, the contribution from the reaction force and the moments resulting from that force should include the effects of a Dynamic Load Factor (DLF) or should use the maximum instantaneous values of forces and moments for that location as determined by the dynamic hydraulic/structural system analysis. This requirement should be satisfied in demonstrating satisfaction of all design limits at all locations of the pipe run and the pressure relief valve for Class 1, 2, and 3 piping. A DLF of 2.0 may be used in lieu of a dynamic analysis to determine the DLF. The SAR should also include a description of the calculational procedures, computer programs, and other methods to be used in the analysis. The analysis should include the time history or equivalent effects of changes of momentum due to fluid flow changes of direction. The fluid states considered should include postulated water slugs where water seals are used and subcooled or saturated liquid if such fluid can be discharged under postulated transient or accident conditions. Applicants for plants utilizing suppression pools should also consider