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:
nts of related piping, and in the event of a system failure. d. Exterior tanks should be located on or above bermed concrete pads. The berms should have a capacity sufficiently larger than the maximum tank volume to accommodate the contents of the tank, including the contents of related piping, in the event of a system failure. Each concrete pad should be lined or sealed with an impermeable membrane. Each bermed area should have provisions for the sampling and release of rainwater. e. Monitoring systems and programs to detect the source and extent of leakage of radioactivity from SSCs, particularly those located below grade, should be deployed as close as possible to the SSC and should be designed to expedite early detection so that remedial action can be taken if necessary. f. To the extent practical, systems containing, transporting, or processing radioactive liquids should not use buried or embedded piping and drains. Underground piping containing radioactive liquids should be enclosed within structured pipe chases with provisions for periodic inspection (visual) or surveillance (leak detection system) to verify piping integrity. For those situations in which pipe chases are not feasible, the use of double-walled lines with built-in leak detection capability should be considered. g. To minimize the leakage of radioactive fluids to ground water, and the leakage of ground water into buildings, system and structural designs should avoid the use of below-grade conduit and piping penetrations through walls that form exterior boundaries. This is particularly applicable to penetrations at or through the floor level. Penetrations through outer walls of a building containing radioactive systems should be sealed to prevent leaks to the environment. The integrity of such seals 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