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:
frequency may be adjusted to that interval that allows adequate measurement and reporting of effluents. If estimating C-14 based on scaling factors and fission rates, a precise and detailed evaluation of C-14 is not necessary. It is not necessary to calculate uncertainties for C-14 or to include C-14 uncertainty in any subsequent calculation of overall uncertainty. 1.10 Abnormal Releases and Abnormal Discharges In the previous revision of the Regulatory Guide 1.21, the terms “release” and “discharge” were synonymous. This regulatory guide uses the term “release” to describe an effluent from the plant (regardless of where the effluent is deposited), whereas the term “discharge” is used only to describe an effluent that enters the unrestricted area. Although the term “release” includes effluents to either (1) the on-site environs or (2) the unrestricted area, for purposes of this regulatory guide, the use of the term “release” will generally be reserved for those instances when an effluent is released from the power plant into the on-site environs. The on-site environs in this context encompass locations outside of nuclear power plant systems, structures, and components as described in the final safety analysis report or ODCM. This is a change in terminology with respect to the definition of “abnormal release” in Regulatory Guide 1.21, Revision 1, which defined abnormal releases to be “from the site boundary.” An “abnormal release” (see glossary) is an unplanned or uncontrolled release of licensed radioactive material from the plant. Abnormal releases may be categorized as either batch or continuous depending on the circumstances. By contrast, an “abnormal discharge” (see glossary) is an unplanned or uncontrolled release of licensed radioactive material to the unrestricted area. Abnormal discharges may also be categorized as either batch or continuous depending on the circumstances. The distinction between the terms “abnormal