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:
not, however, preclude the appropriate use of the insights of the AST in establishing emergency response procedures, such as those associated with emergency dose projections, protective measures, and severe accident management guides. 1.1.5 Applicability to Advanced and Passive Light-Water Reactor Applications The NRC originally created RG 1.183 for use by existing nuclear power reactors to satisfy regulations under 10 CFR 50.34 and 10 CFR 50.67. RG 1.183, Revision 1, extends the applicability of the proposed RG for use by advanced and passive LWR designs in satisfying the radiological dose analysis requirements in 10 CFR Part 50 and 10 CFR Part 52 for safety and siting analyses. New reactor applicants and licensees may use the guidance in RG 1.183, Revision 1 that is applicable to their design to meet the accident radiological consequence analysis requirements in 10 CFR Part 50 or 10 CFR Part 52 for permits, licenses, approvals, or certifications. To review these applications, the staff will use the methodology and assumptions stated in RG 1.183, Revision 1, as are applicable to the design. 1.2 Scope of Implementation The AST described in this guide is characterized by the radionuclide composition and magnitude, chemical and physical form of the radionuclides, and timing of the release of these radionuclides. The accident source term is a fundamental assumption and the basis of a large portion of the facility design. For operating reactors to which 10 CFR 50.67 applies, a complete implementation of an AST would upgrade all existing radiological analyses and would consider the impact of all five characteristics of a source term as defined in 10 CFR 50.2, “Definitions.” However, the NRC staff has determined that there could be implementations for which this level of reanalysis may not be necessary. For holders of operating licenses, as defined in the applicability section of 10 CFR 50.67, two categories of AST implementation are defined: full and selective.