Document: NUREG-0800
Document ID: 936f16a2-5593-4498-8533-ddca55910376
Document Type: srp
Title: COMBUSTIBLE GAS CONTROL IN CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340704.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.5
CFR Part: 
CFR Title: 

Content:
e design of the systems provided for combustible gas control are the relevant requirements of 10 CFR Part 50, §§ 50.44 and 50.46 and General Design Criteria 5, 41, 42 and 43. The requirements are as follows: a. § 50.44 and § 50.46 of 10 CFR Part 50 as it relates to BWR and PWR plants being designed to (a) include means for control of hydrogen that may be generated, following a LOCA, by core metal-water reaction, radiolytic decomposition of water and corrosion of water and corrosion of metals; (b) be provided with the capability for measuring the hydrogen concentra- tion in the containment, insuring a mixed containment atmosphere and con- trolling combustible gas concentrations in the containment; and (c) be provided with an inerted atmosphere or an oxygen deficient condition if certain conditions cannot be met prior to effective operation of the combus- tible gas control system. Postaccident conditions should be such that an uncontrolled hydrogen/oxygen recombination would not take place in the con- tainment, or the plant should withstand the consequences of uncontrolled hydrogen/oxygen recombination without loss of safety function. As a result of the TMI-2 accident a reevaluation of the hydrogen that may be generated following an accident is being undertaken. Item II.B.8 of NUREG-0694 and NUREG-0718 discuss the rulemaking proceedings on degraded core accidents for the different classes of plants. 10 CFR Part 50 will be revised to include the additional requirements for hydrogen control systems and the amounts of hydrogen these control systems will have to accomodate. b. General Design Criterion 5 as it relates to providing assurance that sharing of structures, systems and components important to safety among nuclear 6.2.5-3 Rev. 2 - July 1981 power units will not significantly impair their ability to perform their safety functions. c. General Design Criterion 41 as it relates to systems being provided to control the concentration of hydrogen or oxygen that may