Document: NRC Regulatory Guide
Document ID: 6828ed7d-219b-4105-acf2-37d8a69c3f72
Document Type: regulatory_guide
Title: Use of ARCON Methodology For Calculation Of Accident-Related Offsite Atmospheric Dispersion Factors + HISTORY - HISTORY 08/2021 – DG-4030 , Proposed Revision 0
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML2116/ML21165A005.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-4.28
CFR Part: 
CFR Title: 

Content:
..................................................................................................................... A-1 DG-4030, Page 5 B. DISCUSSION Reason for Issuance This RG provides guidance to industry for complying with and implementing the NRC requirements by endorsing the use of the ARCON computer code (as referenced in RG 1.194 and NUREG/CR-6331) to calculate offsite dispersion values at the EAB and LPZ out to distances of 1,200 m (3,937 ft). ARCON refers to both the ARCON96 and ARCON 2.0 versions of the code. For consistency across versions of the code, and because the updated ARCON 2.0 version only updated the user interface and not the underlying dispersion algorithms, this RG will refer to the code simply as ARCON when the discussion is applicable to either version. RG 1.194 also endorses the use of the ARCON96 computer code however, it is intended for calculating accident-related onsite (control room and technical support center (TSC)) atmospheric dispersion values, which are direct inputs to habitability dose assessments. In addition, RG 1.145 describes the present methodology incorporated into the PAVAN computer code (Ref. 8), as reviewed by the staff using NUREG-0800, Section 2.3.4, for calculating accident-related, offsite atmospheric dispersion values. Background NRC RGs provide approaches that the staff considers acceptable for meeting the regulatory requirements addressed by the specific guide. At the same time, an applicant has the flexibility to propose alternate approaches to the guidance so long as it demonstrates that the applicable regulatory requirements are still met. The PAVAN code has been approved for calculating offsite χ/Q values at the EAB and outer boundary of the LPZ. ARCON96 has been previously approved for calculating onsite χ/Q values to support control room and technical support center habitability dose assessments. Some of the regulatory positions in this RG represent procedures acceptable to the staff beyond those