Document: NUREG-0800
Document ID: 0b3174a2-1530-473d-8cf7-024c17b62e52
Document Type: srp
Title: LONG-TERM ATMOSPHERIC DISPERSION ESTIMATES FOR ROUTINE RELEASES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070730713.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.3.5
CFR Part: 
CFR Title: 

Content:
classification schemes are reviewed for appropriateness to site, plant, and release characteristics. Standard curves of σz with distance are presented in Regulatory Guide 1.111. Modified plume spread parameters may also be considered for unique terrain features such as deserts (Ref. 16) and large bodies of water (Ref. 17). 3. Meteorological Data Meteorological data are reviewed for compatibility with the models utilized, representativeness of conditions within the area of interest, and representativeness of annual average meteorological characteristics in the vicinity of the plant. General criteria for collection and presentation of onsite meteorological data are stated in Regulatory Guide 1.23 and in SRP section 2.3.3. If adequate onsite meteorological data are not available, the reviewer must ensure that adequate conservatism is applied to prevent significant underestimates of airborne concentrations and amount of material deposited. 4. Atmospheric Dispersion and Deposition Factors Used for Routine Releases The atmospheric dispersion factors (χ/Q values) and deposition factors (D/Q values) used for assessment of the consequences of routine radioactive releases are reviewed for appropriateness to site conditions, plant configuration, and release characteristics. Annual average χ/Q and D/Q values are calculated for 16 radial sectors from the site boundary to a distance of 50 miles (80 kilometers) from the plant, as well as for specific locations of potential receptors of interest (e.g., site boundary, residence, garden, cow) 2.3.5-7 Revision 3 - March 2007 as identified by the applicant and as reviewed by the staff in SRP section 11.3. Adjustments of the χ/Q and D/Q values may be necessary to reflect consideration of unusual site and/or meteorological conditions. The resulting χ/Q and D/Q values are provided to the organization responsible for the review of the calculated concentrations and dose consequences of routine airborne radioactive releases as discussed