{"abstract":"The U.S. Nuclear Regulatory Commission (NRC) is issuing a new Regulatory Guide (RG) 1.249 (Revision 0), \"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors.\" This new RG describes an approach for reactor applicants and licensees for determining atmospheric relative concentration ([chi]/Q) values in support of modeling onsite releases to offsite boundaries from a design-basis accident. Also, this RG implements the methodology in RG 1.194, \"Atmospheric Relative Concentrations for Control Room Radiological Habitability Assessments at Nuclear Power Plants,\" for offsite dose locations at boundaries.","action":"Final guide; issuance.","agencies":[{"raw_name":"NUCLEAR REGULATORY COMMISSION","name":"Nuclear Regulatory Commission","id":383,"url":"https://www.federalregister.gov/agencies/nuclear-regulatory-commission","json_url":"https://www.federalregister.gov/api/v1/agencies/383","parent_id":null,"slug":"nuclear-regulatory-commission"}],"body_html_url":"https://www.federalregister.gov/documents/full_text/html/2023/08/21/2023-17908.html","cfr_references":[{"chapter":null,"citation_url":null,"part":50,"title":10},{"chapter":null,"citation_url":null,"part":52,"title":10},{"chapter":null,"citation_url":null,"part":100,"title":10}],"citation":"88 FR 56750","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"Revision 0 to RG 1.249 is available on August 21, 2023.","disposition_notes":null,"docket_ids":["NRC-2021-0133"],"dockets":[{"supporting_documents":[{"title":"Regulatory Guide 1.249, Revision 0 \"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors\"","document_id":"NRC-2021-0133-0013"},{"title":"Regulatory Analysis - Draft Regulatory Guide DG-4030 \"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors\"","document_id":"NRC-2021-0133-0003"},{"title":"Draft Regulatory Guide DG-4030 \"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors\"","document_id":"NRC-2021-0133-0002"}],"agency_name":"NRC","documents":[{"comment_count":null,"comment_start_date":null,"updated_at":"2023-08-21T10:56:04.851-04:00","comment_url":"https://www.regulations.gov/commenton/NRC-2021-0133-0012","allow_late_comments":null,"id":"NRC-2021-0133-0012","comment_end_date":null,"regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":3,"id":"NRC-2021-0133","title":"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors"}],"document_number":"2023-17908","effective_on":null,"end_page":56752,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2023/08/21/2023-17908.xml","html_url":"https://www.federalregister.gov/documents/2023/08/21/2023-17908/regulatory-guide-use-of-arcon-methodology-for-calculation-of-accident-related-offsite-atmospheric","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2023-17908?publication_date=2023-08-21","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2023-08-21/2023-17908/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":265,"last_updated":"2026-04-04 16:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2023-08-21/pdf/2023-17908.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2023-17908.pdf?1692362731","publication_date":"2023-08-21","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2023/08/21/2023-17908.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"Regulatory Guide 1.249, Revision 0 \"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors\"","document_id":"NRC-2021-0133-0013"},{"title":"Regulatory Analysis - Draft Regulatory Guide DG-4030 \"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors\"","document_id":"NRC-2021-0133-0003"},{"title":"Draft Regulatory Guide DG-4030 \"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors\"","document_id":"NRC-2021-0133-0002"}],"comments_count":0,"agency_id":"NRC","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=NRC-2021-0133","supporting_documents_count":3,"docket_id":"NRC-2021-0133","document_id":"NRC-2021-0133-0012","regulation_id_number":null,"title":"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors","checked_regulationsdotgov_at":"2023-08-22T14:00:09Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":56750,"subtype":null,"title":"Regulatory Guide: Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors","toc_doc":"Use of ARCON Methodology for Calculation of Accident-Related Offsite Atmospheric Dispersion Factors","toc_subject":"Guidance:\n","topics":[],"type":"Rule","volume":88}