Document: NRC Regulatory Guide
Document ID: 05969442-49ea-4f4a-a9e2-de3a14628b5e
Document Type: regulatory_guide
Title: Minimization of Contamination and Radioactive Waste Generation:  Life-Cycle Planning - HISTORY 07/2013 – Periodic Review of Revision 0 – No issues identified
Source: NRC Regulatory Guide Division 4
Source URL: https://www.nrc.gov/docs/ML0805/ML080500187.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-4.21
CFR Part: 
CFR Title: 

Content:
ns and backfill, and the selection of backfill material for SSCs containing radioactive materials should: (1) prevent or minimize the ability of leaking contaminants from the facility to reach natural permeable layers or fractured rock; and (2) in the event of leakage to the environment, facilitate the migration of leakage contaminants to designated locations and systems of the facility (e.g., radioactive external waste drains or sumps) for eventual extraction and treatment. p. Backfill material should not contain concentrations of radioactive material above natural background levels at the site. q Proposed operating procedures should include the monitoring of backfill or structural fill designed to transport leakage from radioactive systems for evidence of clogging (e.g., blockage by migrating fines from surrounding soil). r. Potential leakage from any existing adjoining nuclear facility should be prevented from migrating into the excavation and backfill of a new nuclear facility. s. The design ground-water level should be located below the foundation of SSCs containing radioactive liquids so that any leakage is not directly introduced into saturated soils below the foundation. t. Plans for the extraction of ground water or leaked liquid radioactive effluent should consider the potential impact of extraction on the SSC foundation support. u. Monitoring programs should allow for the reevaluation of the location of monitoring sensors and sampling frequency if contaminants are detected. This analysis should provide the technical basis for determining the need for further action. v. Procedures for mitigation if contamination is detected should include use of the conceptual site model and monitoring information to develop event-specific models of contaminant migration before the selection of a remediation strategy. w. When deemed appropriate, ground-water capture zones surrounding SSCs should be designed and operated to provide effective means to isolate and collect