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:
should be periodically verified. h. If a building design includes foundation drains, it should also include the capability for sampling and processing the effluent of those drains. i. To minimize the potential for spreading solid or liquid contamination into the environment, radioactive material handling, staging, storage, and decontamination areas (to support refueling, maintenance and operational activities) should be located inside buildings or in contained areas. j. The radioactive liquid waste treatment system should not include any bypasses or drains that would allow waste to inadvertently circumvent treatment system components or to be released directly to the environment. k. Drain systems for storm water and sanitary sewage should be separate from contaminated waste drain systems. l. The design for any sump or retention pond that has the potential to become contaminated (even if it is not considered a radioactive system) should include a liner and the capability for isolation or collection/routing of overflow to a monitored release path. m. All ingress/egress points for facilities containing radioactive systems should include provisions for preventing leakage/seepage to the outside environment. For example, the use of sills at outside ingress/egress locations or floor grades sloped toward drain channels can help to prevent leakage/seepage to outside grounds/soil. n. Design and construction specifications for major radioactive system barriers such as spent fuel pools and transfer canals should consider measures to minimize the need for seals Appendix A to RG 4.21, Page A-5 (e.g., continuous concrete pours). Alternatively, clear separation between major structures should be considered, with both visual and integrated leak detection. o. The design of excavations 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