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:
, and remediate the affected area (if the licensee deems remediation to be reasonable and necessary). For leaks and spills involving the discharge of radioactive material to the unrestricted area, the dose to members of the public from the leak or spill should be evaluated using realistic or bounding exposure scenarios. (See Attachment 6 to SECY- 03-0069 for more information on use of realistic scenarios.) However, for leaks or spills that occur on site, a realistic dose assessment to an offsite member of the public may become complicated especially if (1) no radioactive material has entered the unrestricted area and (2) there are no members of the public on site. For leaks and spills, licensees should perform surveys that are reasonable to evaluate the potential radiological hazard (as described in 10 CFR 20.1501). As a result, for leaks and spills, licensees may choose to use bounding assessments to estimate the potential hazard. For example, if a leak occurs on site and radioactive material is released at or below the ground surface, the licensee may choose to assess the potential hazard by assuming that a conservatively large (e.g., bounding) volume of water is part of an assumed exposure pathway (e.g., drinking water). Such assumptions would allow the licensee to assess the potential hazard to a hypothetical individual member of the public. A hazard assessment of this sort would be appropriate for inclusion in the supplemental information section of the ARERR. In such cases where there is no real exposure pathway to a member of the public, the licensee should indicate that the hazard assessment is a bounding estimate of the dose to a hypothetical individual member of the public and no actual exposure was received by a real individual member of the public. If licensees choose to notify local authorities of spills or leaks (e.g., because of local ordinances or local and State government agreements), the licensee should review the reporting requirements of 10 CFR