Document: NUREG-0800
Document ID: 15a004f9-6c99-4bc0-a858-efeaea553e8e
Document Type: srp
Title: REACTOR COOLANT SYSTEM HIGH POINT VENTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070440.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.12
CFR Part: 
CFR Title: 

Content:
REVIEW RESPONSIBILITIES Primary - Reactor Systems Branch (RSBSRXB)1 Secondary - None I. AREAS OF REVIEW All light-water nuclear power reactors are required to contain reactor coolant system high point vents in accordance with 10 CFR 50.44(c)(3)(iii). Reactor coolant system high point vents are 2 provided to exhaust noncondensible gases from the primary system that could inhibit natural circulation core cooling. The vent system consists of remotely operated valves at high points in the reactor coolant system to vent gases from the primary system into containment. Since the vents form part of the reactor coolant pressure boundary, design of the vent system shall conform to the requirements of Appendix A to 10 CFR Part 50, "General Design Criteria." In addition, the vent system shall be designed with sufficient redundancy to assure a low probability of inadvertent or irreversible actuation. The vent system's safety function may be required to maintain core coolability following an accident, therefore the system is designed as a safety-related system. RSBSRXB review of reactor coolant system high point vents will 3 include the following specific areas: 1. The location, size, discharge capacity, functions, and discharge area(s) of the vent system. 2. Supporting LOCA analyses for breaks in the vent line to demonstrate compliance with 10 CFR Part 50, § 50.46. 4 DRAFT Rev. 1 - April 1996 5.4.12-2 3. Redundancy and failure modes of the valve train. 4. Procedures for using and not using the vent system, and the bases for these procedures. 5. Information available to the operator for initiating and terminating vent system operation. 6. System environmental qualification to demonstrate compliance with 10 CFR 50.49.5 Review Interfaces6 In addition, the RSBSRXB will coordinate other branch evaluations that interface with the 7 overall review of the system as follows: 1. The Structural EngineeringCivil Engineering and Geosciences Branch (SEBECGB)8 determines the acceptability of