The casks waste is stored in would take bunker buster yields to breach.

All the waste a plant ever produces in its lifetime can be contained with ease on site. Waste certainly isn’t the main issue, though it’s portrayed to be. Cost of deployment and staffing are more prohibitive issues, and both are surmountable. I don’t think it’s a bandaid for all power issues, but it’s a powerful tool that should be used more often, not phased out.