Document: NRC Regulatory Guide
Document ID: 7bdfde6b-2c09-49db-8a3f-863eab24747e
Document Type: regulatory_guide
Title: Control of Combustible Gas Concentrations in Containment + HISTORY - HISTORY 08/2002 – DG-1117 , Proposed Revision 3 Prior to the issuance of DG-1117, RG 1.7 was entitled "Control of Combustible Gas Concentrations in Containment Following a Loss-of-Coolant Accident," to reflect its narrower original scope
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0222/ML022210067.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.7
CFR Part: 
CFR Title: 

Content:
nd inspected, and remain operable with a loss of onsite or offsite power. The NRC staff considers atmosphere mixing systems installed and approved by the NRC as of the effective date of the rule to be acceptable without modification. 4. HYDROGEN GAS PRODUCTION Materials within the containment that would yield hydrogen gas by corrosion from the emergency cooling or containment spray solutions should be identified, and their use should be limited as much as practicable. 5. CONTAINMENT STRUCTURAL INTEGRITY The Proposed Section 50.44 would require that containment structural integrity be demonstrated by use of an analytical technique that is accepted by the NRC staff. This demonstration must include sufficient supporting justification to show that the technique describes the containment response to the structural loads involved. The analysis must address an accident that releases hydrogen generated from 100 percent fuel clad-coolant reaction accompanied by hydrogen burning. Systems necessary to ensure containment integrity must also be demonstrated to perform their function under these conditions. The following criteria of the ASME Boiler and Pressure Vessel Code provide an acceptable method for demonstrating that the requirements are met. i. That steel containments meet the requirements of the ASME Boiler and Pressure Vessel Code (Edition and Addenda as incorporated by reference in 10 CFR 50.55a(b)(1)), Section III, Division 1, Subsubarticle NE - 3220, Service Level C Limits, considering pressure and dead load alone (evaluation of instability is not required); and 7 ii. That concrete containments meet the requirements of the ASME Boiler and Pressure Vessel Code, Section III, Division 2, Subsubarticle CC - 3720, Factored Load Category, considering pressure and dead load alone. These criteria, while being removed from the existing regulations, are acceptable to the NRC staff for meeting the proposed regulations. The acceptability of licensee analyses using the ASME Code