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:
s," Bulletin 503, Bureau of Mines (1952). 12. A. 0. Allen, "The Radiation Chemistry of Water and Aqueous Solutions," Van Nostrand Co., New York (1961). 13. Branch Technical Position ASB 9-2, "Residual Decay Energy for Light Water Reactors for Long-Term Cooling," attached to SRP Section 9.2.5. 14. NUREG-0094, "TMI-Related Requirements for New Operation Licensees," June 1980. 15. NUREG-0718, "Licensing Requrements for Pending Applications for Construc- tion Permits and Manufacturing License," March 1981. 16. NUREG-0737, "Classification of TMI Action Plan Requirements." 6.2.5-10 Rev. 2 - July 1981 APPENDIX A SRP SECTION 6.2.5 DESCRIPTION OF GOGAP INTRODUCTION A digital computer program, COGAP (Combustible Gas Analyzer Program), has been developed by the Containment SystemTsBranch to provide in-house capability for determining hydrogen-oxygen concentrations within reactor containments follow- ing loss-of-coolant accidents. The program can also evaluate the performance of a number of combustible control systems. They are the containment atmosphere dilution system (CAD), the recombiner system, and the backup purge system. DISCUSSION In the event of a loss-of-coolant accident (LOCA), hydrogen and oxygen gases will be generated within the reactor containment by several reactions. They are: 1. Metal-water reaction involving the zirconium fuel cladding and the reactor coolant, producing free hydrogen. 2. Radiolytic decomposition of the post-accident emergency cooling solutions, producing both oxygen and hydrogen. 3. Aluminum corrosion by water solutions, producing hydrogen. 4. Zinc corrosion by water solutions, producing hydrogen. If a sufficient amount of hydrogen is generated, it may react with the 0 present in the containment atmosphere or, in the case of inerted containments, with the oxygen generated following a LOCA. The extent of zirconium-water reaction and associated hydrogen production depends strongly upon the course of events assumed for the accident. Analyti-