Document: NRC Regulatory Guide
Document ID: 42f2dcf0-38ba-4f75-84d4-e60f4bbf9162
Document Type: regulatory_guide
Title: Assessment of Abnormal Radionuclide Discharges in Ground Water to the Unrestricted Area at Nuclear Power Plant Sites Appendix-Simple Ground Water Model for Estimating Offsite Tritium Activity Flux + HISTORY - HISTORY 12/2015 – DG-4025-Proposed New Guide
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML1523/ML15237A388.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.25
CFR Part: 
CFR Title: 

Content:
reference has itself been incorporated by reference into NRC regulations as a requirement, then licensees and applicants must comply with that standard as set forth in the regulation. If the secondary reference has been endorsed in an RG as an acceptable approach for meeting an NRC requirement, then the standard constitutes a method acceptable to the NRC staff for meeting that regulatory requirement as described in the specific RG. If the secondary reference has neither been incorporated by reference into NRC regulations nor endorsed in an RG, then the secondary reference is neither a legally binding requirement nor a “generic” NRC-approved acceptable approach for meeting an NRC requirement. However, licensees and applicants may consider and use the information in the secondary reference, if appropriately justified, consistent with current regulatory practice, and consistent with applicable NRC requirements. DG-4025, Page 7 C. STAFF REGULATORY GUIDANCE ANSI/ANS 2.17-2010 provides an acceptable method for assessing radioactive discharges in ground water to the unrestricted area at nuclear power plant sites. While the standard does not provide a specific model, it provides a graded, risk-informed approach for evaluating the effects of subsurface radionuclide transport. The approach is based on the complexity of geologic and hydrologic conditions, the types of radioactive materials and facility design, the types and effectiveness of engineered and natural barriers, and the proximity to surface water and ground water receptors. A facility that has less significant radionuclide source term, minor subsurface contamination, simple or well-understood hydrogeology, or limited effects on ground water resources generally requires less extensive site characterization, mathematical modeling, and performance-confirmation measures than a facility with significant subsurface contamination that has the potential to exceed national radiation protection standards. The appendix to