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:
ent and Radiation Monitors Calibrations (e.g., of laboratory equipment and continuous radiation monitoring systems used to quantify radioactive effluents) should be performed using reference standards certified by NIST or standards that have been calibrated against NIST-certified standards. Calibration standards should have the necessary accuracy, stability, and range required for their intended use. Continuous radioactivity monitoring systems should be calibrated against appropriate NIST standards. The relationship between concentrations and monitor readings should be determined over the full range of the readout device. Adequacy of the system should be judged on the basis of reproducibility, time stability, and sensitivity. Periodic inservice correlations that relate monitor readings to the concentrations and/or release rates of radioactive material in the monitored release path should be performed to validate the adequacy of the system. These correlations should be based on the results of analyses for specific radionuclides in grab samples from the release path. The use of NIST-traceable sources combined with mathematical efficiency calibrations may be applied to instrumentation used for radiochemical analysis (e.g., gamma spectroscopy systems) if employing a method provided by the instrument manufacturer. Rev. 2 of RG 1.21, Page 25 4.6 Calibration of Measuring and Test Equipment Measuring and test equipment should be calibrated using reference standards certified by NIST or standards that have been calibrated against standards certified by NIST. The calibration standards should be representative of the sample types analyzed and have the necessary accuracy, stability, and range required for their intended use. 4.7 Calibration Frequency Calibrations should generally be performed at regular intervals in accordance with the frequencies established in NUREG-1301 and NUREG-1302. A change in calibration frequency (an increase or decrease) should be based on the