The containment capability of mined subterranean caverns for siting nuclear power plants depends on the flow of groundwater through porous media surrounding the cavern. For a simple cylindrical containment cavern, design correlations were developed relating depth of burial to cavern overpressure. Considering 50 psig as the maximum containment overpressure following a postulated loss-of-coolant accident (LOCA), the minimum depth of burial below the groundwater table for a cavern of 50-ft radius is ∼200 ft. These conditions assure no cavern water flow through the rock to the atmosphere and no cavern contaminant seepage into the groundwater following a postulated LOCA.