Document: NRC Regulatory Guide
Document ID: 4d46a966-d280-43da-9b03-8b0abe7b29ce
Document Type: regulatory_guide
Title: Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2120/ML21204A065.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.183
CFR Part: 
CFR Title: 

Content:
ment free volume. This evaluation should consider the magnitude of the containment volume and exhaust rate, the potential for bypass to the environment, the location of exhaust plenums relative to the surface of the reactor cavity, recirculation ventilation systems, and internal walls and floors that impede streamflow between the surface of the reactor cavity and the exhaust plenums. place during shutdown periods. To be credited in the analysis, the technical specifications should address the appropriate form of isolation. 5 Technical specifications that allow such operations usually include administrative controls to close the airlock, hatch, or open penetrations within 30 minutes. Such administrative controls generally require that a dedicated individual be present, with necessary equipment available, to restore containment closure should a fuel handling accident occur. Radiological analyses should generally not credit this manual isolation. DG-1389, Appendix B, Page B-7 APPENDIX B REFERENCES B-1. U.S. Nuclear Regulatory Commission (NRC), “Re-evaluation of the Fission Product Release and Transport for the Design-Basis Accident Fuel Handling Accident,” Staff Technical Paper, 2019. (ADAMS Accession No. ML19248C647). B-2. US. NRC, Staff Technical Paper, “Internal Memorandum, from Elijah Dickson to Kevin Hsueh, “Example Calculation of Re-Evaluated Fuel Handing Accident Fission Product Transport Model for Draft RG 1.183 Revision 1 (2021).” August 2021. (ADAMS Accession No. ML21190A040). B-3. U.S. NRC, “Iodine Evolution and pH Control,” NUREG/CR-5950, Oak Ridge National Laboratory, December 1992 (ADAMS) Accession No. ML063460464). B-4. U.S. NRC, “Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Post-Accident Engineered-Safety-Feature Atmosphere Cleanup Systems in Light-Water-Cooled Nuclear Power Plants,” Regulatory, Guide 1.52, Revision 4, September 2012. (ADAMS Accession No. ML12159A013). DG-1389, Appendix C, Page