Document: NRC Regulatory Guide
Document ID: 377c2606-4b7c-4c7f-997d-37aed1680452
Document Type: regulatory_guide
Title: Performance, Testing, and Procedural Specifications for Thermoluminescence Dosimetry: Environmental Applications + HISTORY - HISTORY 10/2018 – DG-4019 , Proposed Revision 2 11/2014 – Periodic Review of Revision 1 – Revise (Rev. 2)
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML1808/ML18087A169.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.13
CFR Part: 
CFR Title: 

Content:
t radiation levels and dose to members of the public in the unrestricted area and the controlled area of a licensed facility. In 1991, the NRC revised 10 CFR Part 20 to include a new requirement in 10 CFR 20.1302 stating that licensees shall perform, as appropriate, surveys of radiation levels in the unrestricted area and the controlled area of a licensed facility to demonstrate compliance with the dose limits for individual members of the public. Subsequently, ANSI N545-1975 was withdrawn and replaced with ANSI/Health Physics Society (HPS) N13.37-2014, “Environmental Dosimetry—Criteria for System Design and Implementation.” ANSI/HPS N13.37-2014 provides revised environmental dosimetry performance specifications and data analysis methods to comply with 10 CFR Part 20 that are based on the premise that the background radiation at each location is constant. Appendix A of this RG provides a summary of ANSI N13.37-2014 data-analysis methods. ANSI N13.37-2014 introduced four important terms: (1) The “minimum quantifiable dose” (MQD) is the smallest amount of dose that can be accurately measured with less than or equal to a 7 percent coefficient of variation. The MQD is used to evaluate the adequacy of a dosimeter system design. (2) The “minimum differential dose” (MDD) is the smallest amount of dose that can be detected and attributed to a facility’s operation (e.g., the incremental dose above background). The MDD is a nominal 5 to 6 mrem (0.05 to 0.06 mSv) per quarter or 10 to 12 mrem (0.01 to 0.12 mSv) per year. DG-4019, Page 7 (3) The FRD is the actual amount of dose detected (above natural background) attributed to the facility. If the FRD is less than the MDD, the FRD is “not detected.” (4) The “extraneous dose” is the extra dose accumulated on a dosimeter before and after field deployment. Extraneous dose is due to radiation sources other than those at the field monitoring location, such as natural background (when the dosimeter is not