Document: NRC Regulatory Guide
Document ID: d812c779-c17b-4eb3-9d66-b532cd68bd03
Document Type: regulatory_guide
Title: Decommissioning Planning During Operations + HISTORY - HISTORY 12/2011 – DG-4014 , Proposed New Guide
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML1115/ML111590642.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.22
CFR Part: 
CFR Title: 

Content:
er that minimizes the introduction of residual radioactivity into the site, including the subsurface, to facilitate remediation of the site for unrestricted use at the time of license termination. The DPR also amends 10 CFR 20.1501(a) to explicitly include a requirement for radiological surveys in the subsurface necessary to evaluate residual radioactivity at licensed sites. This revised regulation retains its existing limit of “reasonable under the circumstances.” The term “residual radioactivity” is defined in 10 CFR 20.1003, “Definitions,” as any radioactivity from licensed and unlicensed sources that has been introduced to the site by activities under the licensee’s control. In the Statements of Consideration for the rule, a “significant amount of residual radioactivity” is defined as an amount that would require remediation during decommissioning to meet the unrestricted use criteria specified in 10 CFR 20.1402. Significant residual radioactivity in subsurface media, such as soil, is an important component of waste because, after operations cease, it must be removed and disposed off site to meet unrestricted use criteria. The new 10 CFR 20.1501(b) requires licensees to keep records of the required surveys describing the locations and amounts of residual radioactivity identified at the site with other records important to decommissioning. It does not require licensees to submit reports of survey results. The NRC’s technical basis for identifying the effect that significant residual radioactivity has on decommissioning costs is a 2005 NRC staff study (Ref. 9). The purpose of the study was to compile and evaluate experience at sites undergoing decommissioning to identify the types of events that have caused DG-4014, Page 5 subsurface contamination. Evaluating these events provided a means for NRC staff to identify the potential for future subsurface contamination at currently operating facilities. The study identified a number of events that