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:
restricted area and the controlled area (per 10 CFR Part 20 definitions), c. boundary of the unrestricted area for liquid effluents (e.g., at the end of the pipe or entrance to a public waterway), and d. boundary of the unrestricted area for gaseous effluents (e.g., the site boundary). Rev. 2 of RG 1.21, Page 10 4. Dose calculation methodologies should be described for exposure pathways and routes of exposure that are identified in Regulatory Guide 1.109, if applicable. 5. Dose calculation methodologies for direct radiation should be described if necessary (e.g., when assessing direct radiation from the facility). The methodology should include background subtraction, or if appropriate, extrapolation of radiation measurements to points of interest (e.g., to the individual members of the public likely to receive the highest dose). The unrestricted area may be defined separately for each of the following: (1) liquid effluents, (2) gaseous effluents, and (3) if appropriate, for other radiological controls such as direct radiation. 1.3 Monitoring a Significant Release Point A significant release point is any location, from which radioactive material is released, that contributes greater than 1 percent of the activity discharged from all the release points for a particular type of effluent considered. Regulatory Guide 1.109 lists the three types of effluent as (1) liquid effluents, (2) noble gases discharged to the atmosphere, and (3) all other radionuclides discharged to the atmosphere. The ODCM should list significant release points. Significant release points should be monitored in accordance with the ODCM. If a new significant release point is identified and is not listed in the ODCM, licensees should (1) establish an appropriate sampling interval (e.g., in site-specific procedures) and (2) update the ODCM within a reasonable timeframe (e.g., yearly). Releases from a significant release point should be assessed based on an appropriate combination of actual sample