Document: NRC Regulatory Guide
Document ID: a5cfec96-8785-464b-ada8-dc4424b90606
Document Type: regulatory_guide
Title: Quality Assurance for Radiological Monitoring Programs
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML0630/ML063060429.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.15
CFR Part: 
CFR Title: 

Content:
rab sample. DG-4010, Page 14 7.3 Grab Sampling of Effluent Process Streams Whenever practicable, effluent releases should be batch-controlled and released when the volume to be released has been mixed sufficiently to ensure uniform concentration. Sampling and analysis for each batch should be performed, and release conditions set, before release. A certain percentage of all batch releases should have field duplicates taken either before or during the release to assess the reproducibility of sampling and the effectiveness of the mixing process before release. Where possible, samples that are spatially or temporally separated should be collected periodically to verify representativeness. For continuous-effluent discharges, composite samplers should be employed. However, periodic grab samples may be used when composite sampling of a continuous discharge point is not feasible. When grab samples are collected instead of composite samples, the time, location, and frequency should be designed to ensure that the sample is representative of the radioactive materials released. 7.4 General Quality Control Considerations The QC plan should address the following items: C Sampling should be performed using calibrated instruments and equipment when taking a composite sample. C Collection efficiencies based on the physical configuration of the sampling point and the type of collector should be documented. Vendor-supplied data may be used where adequate documentation exists to ensure the reliability and accuracy of data. C Volumes of tanks and containers should be established during initial installation and should be verified again following any physical changes that could alter the system configuration. • The frequency of duplicates and REPLICATES6 should be established based on time (for continuous discharges) or number of batches (for batch discharges). Procedures for continuous sampling should use methods that are designed to ensure that the sample is representative of the