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:
rticle NB-7000. Also, sufficient available margin should account for uncertainties in the design and operation of the plant assuming: 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 initiates the reactor scram. iv. The discharge flow is based on the rated capacities specified in ASME Code Article NB-7000 for each type of valve. In addition, the designs of the safety valves should have sufficient capacity to limit the pressure to less than 110 percent of the RCPB design pressure during the most severe infrequent event, as specified by ASME Code Article NB-7000. C. A single malfunction or failure of an active component should not preclude safety-related portions of the system from functioning as required during normal operations, adverse environmental occurrences, and accident conditions, including loss of offsite power. Full credit is allowed for spring-loaded safety valves designed in accordance with the requirements of ASME Code Article NB-7511.1. 4. Design Requirements for PWRs Operating at Low Temperature (Startup, Shutdown). The design of the low-temperature overpressure protection (LTOP) system or the cold overpressure mitigation system (COMS) should be in accordance with the requirements of Branch Technical Position (BTP) 5-2. The LTOP system or COMS should be operable during startup and shutdown conditions below the enable temperature defined in paragraph II.2 of BTP 5-2. 5. Testing and Inspections. The performance of tests and inspections should occur before operation and during startup to functionally demonstrate that the overpressure protection system, as installed, meets all design requirements. 6. Technical Specifications. The technical