Depends on if it can short its charge to ground I guess, and how fast. An uncharged concrete capacitor is of course pretty harmless even if it cracks, so perhap

Depends on if it can short its charge to ground I guess, and how fast. An uncharged concrete capacitor is of course pretty harmless even if it cracks, so perhaps you could pour some strain gauges into it so you get advance warning of impending problems.