Document: NRC Regulatory Guide
Document ID: de79d411-4fc9-456e-a5a0-f4a910ca4c9a
Document Type: regulatory_guide
Title: Assumptions Used for Evaluating a Control Rod Ejection Accident for Pressurized Water Reactors (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2111/ML21119A157.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.77
CFR Part: 
CFR Title: 

Content:
egulatory requirements for evaluating the habitability of a nuclear power plant (NPP) control room (CR) during a postulated hazardous chemical release. Releases of hazardous chemicals,1 on site or off site, can result in the nearby CR becoming uninhabitable. The driver of this RG is Title 10 of the Code of Federal Regulations (10 CFR) Part 50, “Domestic Licensing of Production and Utilization Facilities,” Appendix A, “General Design Criteria for Nuclear Power Plants,” General Design Criterion (GDC) 19, “Control Room,” (Ref. 1). GDC 19 requires operating reactor licensees to provide a CR from which actions can be taken to maintain the nuclear power unit in a safe condition under accident conditions, including loss-of-coolant accidents. This RG contains technical bases and guidelines that are acceptable to the NRC staff for use in assessing the habitability of a CR during and after a postulated external release of hazardous chemicals (e.g., vapor and gaseous) from a stationary source on-site and multiple mobile sources off-site, based on the immediately dangerous to life or health (IDLH) values (Ref. 2). Applicability This guidance applies to applicants and reactor licensees under 10 CFR Part 50 and 10 CFR Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants” (Ref. 3). Although this RG is meant for NPP applications, the technical basis and analytical methods described for chemical safety 1. As defined by the Occupational Safety and Health Administration’s (OSHA’s) Hazard Communication Standard, https://www.osha.gov/hazcom, a hazardous chemical is any chemical that can cause a physical or health hazard. DG-1387, Page 2 could also be implemented for nonreactor and advanced non-light-water reactor facilities to address habitability concerns involving use or storage of hazardous or toxic chemicals. Applicable Regulations • The GDC in Appendix A to 10 CFR Part 50 establish minimum requirements for the principal design criteria