Document: NUREG-0800
Document ID: 33a67dd5-21e3-4458-9085-803f75466a73
Document Type: srp
Title: OVERPRESSURE PROTECTION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070540076.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.2.2
CFR Part: 
CFR Title: 

Content:
aterial specifications by compliance with the applicable provisions of the ASME Code and by acceptable application of material code cases, as described in Regulatory Guide 1.84. The specifications for permitted materials are identified in Appendix I to Section III of the ASME Code or described in detail in Parts A, B, and C of Section II of the ASME Code. Regulatory Guide 1.84 describes acceptable material code cases and guidelines for application in light-water-cooled nuclear power plants that may be used in conjunction with the above specifications. 2. Design Requirements for BWRs Operating at Power A. For overpressure protection during power operation of the BWR reactor, the designs of the pilot-operated relief valves with auxiliary actuation devices, isolation condensers, or other pressure dissipation systems should have 5.2.2-6 Revision 3 - March 2007 sufficient capacity to preclude actuation of safety valves during normal operational transients when assuming the following conditions at the plant: i. The reactor is operating at the licensed core thermal power level. ii. All system and core parameters have values within normal operating range that produce the highest anticipated pressure. iii. All components, instrumentation, and controls function normally. B. The design of safety valves should have sufficient capacity to limit the pressure to less than 110 percent of the RCPB design pressure during the most severe AOO with reactor scram, as specified by ASME Code Article NB-7000. Sufficient available margin should account for uncertainties in the design and operation of the plant, assuming the following: i. The reactor is operating at a power level that will produce the most severe overpressurization transient. ii. All system and core parameters have values within normal operating range, including uncertainties and technical specification limits that produce the highest anticipated pressure. iii. The second safety-grade signal from the reactor protection system