Document: NRC Regulatory Guide
Document ID: 4e88bc9c-73b4-419d-a312-fe7e31653337
Document Type: regulatory_guide
Title: Use of ARCON Methodology For Calculation Of Accident-Related Offsite Atmospheric Dispersion Factors
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2116/ML21165A005.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.249
CFR Part: 
CFR Title: 

Content:
for determining atmospheric relative concentration (χ/Q) values in support of modeling onsite releases to offsite boundaries from a design-basis accident (DBA). This guidance provides procedures for using the ARCON code to estimate χ/Qs at the exclusion area boundary (EAB) and the outer boundary of the low-population zone (LPZ) out to distances of 1,200 meters (m) (3,937 feet (ft)) from the nearest edge of a building within the powerblock area (PBA). Additionally, this guidance implements the methodology in RG 1.194, “Atmospheric Relative Concentrations for Control Room Radiological Habitability Assessments at Nuclear Power Plants” (Ref. 1) for offsite dose locations at boundaries out to distances of 1200 meters (m) (3,937 ft). Also, this RG provides new guidance on plausible alternate meteorological monitoring approaches. Applicability This RG applies to reactor applicants and licensees subject to Title 10 of the Code of Federal Regulations (10 CFR), Part 50, “Domestic Licensing of Production and Utilization Facilities” (Ref. 2); 10 CFR Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants” (Ref. 3); and 10 CFR Part 100, “Reactor Site Criteria” (Ref. 4). The relevance of this guidance will likely be applicable to plants with limited distances associated with the EAB and LPZ boundaries. Applicable Regulations The NRC regulations related to siting and licensing of stationary nuclear power facilities require DG-4030, Page 2 that applicants provide an analysis and evaluation of the facility’s siting and the design and performance of structures, systems, and components (SSCs) of the facility with the objective of assessing the risk to public health and safety resulting from facility operation. These regulations are the following: • 10 CFR Part 50 provides regulations for licensing production and utilization facilities. o 10 CFR 50.34(a)(1)(ii)(D) requires an applicant for a construction permit to include a safety assessment of