Document: NRC Regulatory Guide
Document ID: 67130ae3-9621-4967-b1dc-79f9cbef13e1
Document Type: regulatory_guide
Title: Pressurized-Water Reactor Control Rod Ejection and Boiling-Water Reactor Control Rod Drop Accidents + HISTORY - HISTORY 11/2016 – DG-1327 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1612/ML16124A200.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.236
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Content:
Regulatory Commission (NRC) considers acceptable when analyzing a postulated control rod ejection (CRE) accident for pressurized-water reactors (PWRs) and a postulated control rod drop (CRD) accident for boiling-water reactors (BWRs). It defines fuel cladding failure thresholds for ductile failure, brittle failure, and pellet-clad mechanical interaction (PCMI) and provides radionuclide release fractions for use in assessing radiological consequences. It also describes analytical limits and guidance for demonstrating compliance with applicable regulations governing reactivity limits. Applicability This guide applies to applicants and reactor licensees subject to Title 10 of the Code of Federal Regulations (10 CFR), Part 50, “Domestic Licensing of Production and Utilization Facilities” (Ref. 1) and 10 CFR Part 52 “Licenses, Certifications, and Approvals for Nuclear Power Plants” (Ref. 2). Applicable Regulations • 10 CFR Part 50, “Domestic Licensing of Production and Utilization Facilities,” provides for the licensing of production and utilization facilities. o Appendix A to 10 CFR Part 50, “General Design Criteria for Nuclear Power Plants,” contains general design criteria (GDC) for nuclear power plants. Criterion 28 (GDC 28), “Reactivity Limits,” requires that the reactivity control systems be designed with appropriate limits on the potential amount and rate of reactivity increase to assure that the effects of postulated DG 1327, Page 2 reactivity accidents can neither: (1) result in damage to the reactor coolant pressure boundary greater than limited local yielding, nor (2) sufficiently disturb the core, its support structures or other reactor pressure vessel internals to impair significantly the capability to cool the core. GDC 28 also requires that these postulated reactivity accidents include consideration of rod ejection (unless prevented by positive means), rod dropout, steam line rupture, changes in reactor coolant temperature and