Document: NUREG-0800
Document ID: b085cd1c-2d74-4547-b757-d8513d0cb353
Document Type: srp
Title: OVERPRESSURE PROTECTION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070419.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.2.2
CFR Part: 
CFR Title: 

Content:
the design and operation of the plant assuming: (1) The reactor is operating at a power level that will produce the most severe overpressurization transient. (2) All system and core parameters are at values within normal operating range, including uncertainties and technical specification limits that produce the highest anticipated pressure. (3) The reactor scram is initiated by the second safety-grade signal from the reactor protection system. (4) The discharge flow is based on the rated capacities specified in the ASME Boiler and Pressure Vessel Code, for each type of valve. 3. Full credit is allowed for spring-loaded safety valves designed in accordance with the 19 requirements of the ASME Boiler and Pressure Vessel Code (Reference. 716) . 20 B. The low temperature, overpressure protection (LTOP) system shall be designed in accordance with the requirements of Branch Technical Position RSB 5-2 attached to this SRP section (Reference. 35) . The LTOP system shall be operable during startup and 21 shutdown conditions below the enable temperature defined in paragraph B.2. of RSB 5-2. Technical Rationale:22 The technical rationale for application of the above acceptance criteria to the overpressure protection system is discussed in the following paragraphs: 1. GDC 15 requires that the reactor coolant pressure boundary be designed, constructed, and tested with sufficient margin to assure that design conditions are not exceeded during normal operation or anticipated operational occurrences. The overpressure protection system is relied upon to maintain reactor coolant system pressure within acceptable design limits during certain analyzed transients. Application of GDC 15 to the overpressure protection system provides assurance that the reactor coolant pressure boundary will have an extremely low probability of failure during transients. 2. GDC 31 requires that the reactor coolant pressure boundary be designed with sufficient margin to preclude brittle fracture during