Document: NRC Regulatory Guide
Document ID: 96baa826-d3bb-478b-8f38-e74500f6d433
Document Type: regulatory_guide
Title: 06/2009 (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0911/ML091170109.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.21
CFR Part: 
CFR Title: 

Content:
trolled release—A radioactive release is considered to be “controlled” if (1) the release was conducted in accordance with methods, and without exceeding any of the limits, outlined in the ODCM, or (2) if one or more of the following three items are true: 1. The radioactive release had an associated, pre-planned method of radioactivity monitoring that assured the release was properly accounted and was within the limits set by 10 CFR 20 and 10 CFR 50. 2. The radioactive release has an associated, pre-planned method of termination (and associated termination criteria) that assured the release was properly accounted and was within the limits set by 10 CFR 20 and 10 CFR 50. 3. The radioactive release had an associated, pre-planned method of adjusting, modulating, or altering the flow rate (or the rate of release of radioactive material) that assured the release was properly accounted and was within the limits set by10 CFR 20 and 10 CFR 50. conversion factor—A factor (e.g., microcuries per cubic centimeter per counts per minute (μCi/cc/cpm)) used to estimate a radioactivity concentration in an effluent based on a gross radioactivity measurement (e.g., counts per minute). D/Q—A dispersion parameter for estimating the dose to an individual at a specified (e.g., controlling) location. D/Q may be described as the downwind surface or ground concentration (D) (e.g., in units of microcuries per square meter (μCi/m2)) of radioactive material at a location, divided by the release activity (Q) (e.g., in units of microcuries, μCi). D/Q is thus a normalized downwind surface concentration per unit release and can be used to determine the surface or ground radioactivity concentration during a measured effluent release. The units of D/Q are reciprocal square meters. Rev. 2 of RG 1.21, Page 43 determination—A quantitative evaluation of the release or presence of radioactive material under a specific set of conditions. A determination may be made by direct or indirect