Document: NUREG-0800
Document ID: 97794ae3-595f-4668-8cfe-f438587bc747
Document Type: srp
Title: COMBUSTIBLE GAS CONTROL IN CONTAINMENT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070620006.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.5
CFR Part: 
CFR Title: 

Content:
tion in a severe core melt sequence with a failed reactor vessel. If a sufficient amount of combustible gas is generated, it may react with the oxygen present in the containment at a rate rapid enough to breach the containment or cause a leakage rate in excess of Technical Specification limits. Additionally, the associated pressure and temperature increase could damage systems and components essential to continued control of the post- accident conditions. The review includes the following general areas: 1. The production and accumulation of combustible gases within the containment following a beyond-design-basis accident. 2. The capability to mix the combustible gases with the containment atmosphere and prevent high concentrations of combustible gases in local areas. 3. The capability to monitor combustible gas concentrations within containment, and, for inerted containments, oxygen concentrations within containment. 4. The capability to reduce combustible gas concentrations within containment by suitable means, such as igniters. The specific areas of review are as follows: 1. Analysis of combustible gas (e.g., hydrogen, carbon monoxide, oxygen) production and accumulation within the containment following a beyond-design-basis accident. 2. Analysis of the functional capability of the systems or passive design features provided to mix the combustible gas within the containment. 3. Analysis of the functional capability of the systems provided to reduce combustible gas concentrations within the containment. 4. Analyses of the capability of systems or system components to withstand dynamic effects, such as transient differential pressures that would occur early in the blowdown phase of an accident. 6.2.5-3 Revision 3 - March 2007 5. Analyses of the consequences of single active component malfunctions, to meet GDC 41. 6. The quality classification of each system. 7. The seismic design classification of each system. 8. The results of qualification tests performed on