Document: NUREG-0800
Document ID: 112961d5-bbf7-4ebc-8a51-ee8e2292ddbc
Document Type: srp
Title: LONG-TERM DIFFUSION ESTIMATES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340585.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.3.5
CFR Part: 
CFR Title: 

Content:
relfect con- sideration of unusual site and/or meteorological conditions. Annual average X/Q and D/Q values at the specified receptor locations and at standard distances in the 16 radial sectors from the site boundary to a distance of 50 miles from the plant are provided to the RAB for the cal- culation of appropriate doses. IV. EVALUATION FINDINGS The reviewer verifies that appropriate atmospheric dispersion models, with adequate onsite meteorological data as input to the models, have been used to calculate relative concentration and relative deposition at appropriate dis- tances and directions from postulated release points during routine airborne releases of radioactive gases. The input to the Safety Evaluation Report will also include a summary of the relative concentration (X/Q) and relative deposition (D/Q) calculated by the staff, reference to diffusion models used, and a comparison between the values computed by the staff and the applicant. The reviewer's evaluation must support the following type of concluding state- ment, to be included in the staff's Safety Evaluation Report: Based on the meteorological data provided by the applicant and an atmos- pheric dispersion model that is appropriate for the characteristics of the site and release points, the staff concludes that representative atmospheric transport and diffusion conditions have been calculated for the locations of potential receptors. The characterization of atmospheric transport and diffusion conditions-satisfies the criteria described in Regulatory Guide 1.111 and are appropriate for the evaluation to demon- strate compliance with the numerical guides for doses contained in 10 CFR Part 50, Appendix I. Any deviation from the acceptance criteria should be explained by a statement that the applicant has provided an alternative approach that the staff has reviewed and found to be acceptable. 2; 3. 5-4 Rev. 2 - July 1981 V. IMPLEMENTATION The following is intended to provide guidance to applicants