They were designed with that in mind though. They were built to withstand an plane crash or attack.

You may have seen the famous test of ramming a F4 Phantom into a reinforced concrete walls without much effect: https://www.youtube.com/watch?v=F4CX-9lkRMQ

It's certainly possible to blow them up, but they very unlikely to melt down like Chernobyl did anymore due to all the effort put into preventing that. Easier to just launch radioactive materials at your enemy if that's the result you want.