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:
) for various radionuclides should be well characterized. Grab samples should be collected at scheduled frequencies (see NUREG-1301 and NUREG-1302 or as approved in Generic Letter 89-01 submittals) to quantify specific radionuclide concentrations and release rates. The frequency of sample collection and radionuclide analyses should be based on the degree of variance in (1) the magnitude of the discharge and (2) the relative radionuclide composition from an established norm. Where the magnitude of the discharge and the relative nuclide composition of a continuous release vary significantly over the course of the discharge period, a combination of grab samples and continuous monitor readings can assist in accurately estimating the discharge. Continuous monitoring data (e.g., chart recorder data), as well as grab sample data, should be reviewed periodically and used to identify this variance from the established norm. Periodic evaluations should be made between gross radioactivity measurements and grab sample analyses of specific radionuclides. These evaluations should be used to verify (or modify) the conversion factors that correlate radiation monitor readings and concentrations of radionuclides in effluents. Rev. 2 of RG 1.21, Page 14 1.7 Monitoring Batch Releases For batch releases, measurements should be performed to identify principal radionuclides before a release. In those cases in which an analysis of specific “hard-to-detect” radionuclides (such as strontium- 89/90 and iron-55 in liquid releases) cannot be done before release (see NUREG-1301 and NUREG- 1302), representative samples should be collected for the purpose of subsequent composite analysis. The composite samples should be analyzed at the scheduled frequencies specified in NUREG-1301 and NUREG-1302 or, for less-significant release points, at the frequencies specified by the licensee. (See Regulatory Position 1.4.) The use of continuously indicating radiation monitoring system results may be