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:
sees should make “maximum” assumptions for food consumption and occupancy factors at actual locations when assessing dose to the maximum exposed individual, unless they have determined and applied site-specific (actual) data. In lieu of assessing dose to real individuals, bounding dose assessments may also be used for compliance with 10 CFR Part 50, Appendix I (see the section titled “Bounding Assessments”). The objective of Appendix I is to provide numerical guides for design objectives and limiting conditions for operation to ensure that radioactive effluent control equipment is effective in reducing emissions to ALARA levels. The numerical guidance pertains to quarterly and annual dose criteria at or beyond the unrestricted area from current-year effluent discharges. The Appendix I related calculations do not include dose from radioactivity in prior-year, accumulated, effluent discharges (e.g., last year’s radioactivity remaining in lake water is excluded). Note: However, the dose calculations for Rev. 2 of RG 1.21, Page 30 demonstrating compliance with the EPA limits do include accumulated radioactivity. (See Section 5.8 below.) The exposure pathways and routes of exposure identified in Regulatory Guide 1.109 and other exposure pathways and routes of exposure that may arise because of unique conditions at a specific site should be considered if they are likely to contribute significantly to the total dose. Other exposure pathways are considered significant if a conservative evaluation yields an additional dose increment equal to or more than 10 percent of the total from all exposure pathways considered in RG 1.109 (see the regulatory position C in Regulatory Guide 1.109). An evaluation of other exposure pathways (not included in dose assessments) should be performed and maintained for purposes of demonstrating compliance with staff position C in Regulatory Guide 1.109. A thoroughly designed and documented evaluation of a less significant release point