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:
lemented by 39 Regulatory Guide 1.100, and Regulatory Guide 1.92and SEP 3.92, 3.43, and 3.10. 40 41 Environmental qualifications are in accordance with the May 23, 1980 Commission Order and Memorandum (CLI-80-21)10 CFR 50.49.42 1211. Procedures to effectively operate the vent system must consider when venting is needed and when it is not needed. A variety of initial conditions from which venting may be required shall be considered. Operator actions and the necessary instrumentation shall be identified. Technical Rationale43 The technical rationale for application of the above acceptance criteria to the RCS vent system is discussed in the following paragraphs: 1. 10 CFR 50.44(c)(3)(iii) requires that light-water nuclear power reactors be designed with RCS high point vents to maintain adequate core cooling if the accumulation of noncondensible gases would cause the loss of function of the core cooling systems. This regulation further requires that the use of these vents during and following an accident must not aggravate the challenge to containment or the course of the accident. During the TMI-2 accident a substantial volume of hydrogen was generated in the primary DRAFT Rev. 1 - April 1996 5.4.12-6 system. To resolve concerns that such a gas volume could interfere with post-accident natural circulation or pump operation, the foregoing regulation was promulgated. This rule establishes specific design requirement that must be met by all license applicants. Compliance with 10 CFR 50.44(c)(3)(iii) assures that there is a means to exhaust gases from the reactor coolant system that might otherwise inhibit long term cooling following an accident, thereby ensuring that adequate reactor core cooling is established and maintained, and additional challenges to containment integrity are not created. 2. 10 CFR 50.46(b) establishes specific reactor core temperature, cladding oxidation, hydrogen generation, and cooling requirements that are designed to protect the fuel and fuel