Document: NRC Regulatory Guide
Document ID: 687c884d-2807-4ca3-ac21-69b87c59f4ab
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:
clude the EAB and the outer boundary of the LPZ. Large light-water nuclear power plants typically have EAB and LPZ distances that range from 800 to 6,000 m (2,625 to 19,685 ft), whereas expected small modular reactor and advanced reactor designs are postulated to include EAB and LPZ distances in the range of 80 to 400 m (262.5 to 1,312.3 ft). The NRC has determined that the ARCON computer code, which was developed to model shorter distances in the vicinity of buildings typical of control room habitability dose evaluations, is acceptable for modeling EAB and LPZ χ/Q values at relatively short distances. The ARCON dispersion algorithms are based on field measurements taken out to distances of 1,200 m (3,937 ft) (Ramsdell et. al, 1998) (Ref. 10). Therefore, this guidance is applicable to EAB and LPZ distances from the PBA to a distance of 1,200 m (3,937 ft). 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,” published in the Federal Register on July 10, 2014 (Ref. 11), and Management Directive and Handbook 6.6, “Regulatory Guides,” dated May 2, 2016 (Ref. 12). The NRC staff did not identify any IAEA Safety Requirements or Guides with information related to the topic of this RG. DG-4030, Page 7 C. STAFF REGULATORY GUIDANCE 1. General Considerations ARCON96, as described in NUREG/CR-6331, “Atmospheric Relative Concentrations in