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:
, RG 1.78, Revision 1, covered both toxic and asphyxiating chemicals and recognized that the asphyxiating chemicals should only be DG-1387, Page 5 considered in CR habitability determinations if their release could result in displacement of a significant fraction of the CR air and result in an oxygen-deficient atmosphere. Consistent with risk-informed regulatory decision-making, this RG revision encourages licensees to make greater use of risk insights in submitting applications for plant-specific changes to the licensing basis, using the guidance provided in RG 1.174. Further, this RG revision continues to provide flexibility for licensees to use traditional engineering approaches. Also, consistent with the intent of SECY-00-0191, “High-Level Guidelines for Performance-Based Activities,” dated September 1, 2000 (Ref. 12), on performance-based initiatives, this RG revision provides performance-based guidance rather than traditional, prescriptive guidance. Consideration of International Standards The International Atomic Energy Agency (IAEA) works with member states and other partners to promote the safe, secure, and peaceful use of nuclear technologies. The IAEA develops Safety Requirements and Safety Guides for protecting people and the environment from harmful effects of ionizing radiation. This system of safety fundamentals, safety requirements, safety guides, and other relevant reports, reflects an international perspective on what constitutes a high level of safety. To inform its development of this RG, the NRC considered IAEA Safety Requirements and Safety Guides pursuant to the Commission’s International Policy Statement (Ref. 13) and Management Directive and Handbook 6.6, “Regulatory Guides” (Ref. 14). The following IAEA Specific Safety Guide (SSG) documents were considered in the development/update of this RG: • IAEA SSG-3, “Development and Application of Level 1 Probabilistic Safety Assessment for Nuclear Power Plants,” issued 2010 (Ref.