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:
receptors located at the EAB and LPZ. The ARCON code should be obtained and maintained under an appropriate software quality assurance program that complies with the applicable criteria of Appendix B, “Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants,” to 10 CFR Part 50 and applicable industry consensus standards to which the licensee has committed. Certain locations are affected by atmospheric transport and diffusion conditions that may be more restrictive than assumed in the contiguous 48 states, including effects caused by variations in the duration of daylight and darkness (e.g., limited inversion depths, extended persistence of various conditions). If a given design may be deployed in locations characterized by extreme and persistent restrictive dispersion conditions (e.g., in Alaska) the applicability of the dispersion algorithms in ARCON may not apply or may require further modification. 2.1 Meteorological Data Input This section addresses the meteorological data used as input to ARCON for dispersion estimates to the EAB and LPZ. Meteorological data are input into ARCON using meteorological data files. Appendix A to RG 1.194 provides information on the structure and content of the meteorological data set and input parameters used by the ARCON code. If meteorological data are not needed to support dispersion modeling but only to develop summaries (potentially for design certification, standard design approval, and manufacturing license applications), then an applicant may consider it unnecessary to establish an onsite monitoring program. NUREG-0800 affords an applicant some flexibility in the approach used for meteorological monitoring (i.e., alternative approaches may be used if an applicant provides sufficient justification for doing so and the relevant requirements in the applicable regulations are met). DG-4030, Page 8 2.1.1. Onsite Meteorological Data The meteorological data needed for χ/Q calculations using ARCON or