But if you think about it, there are a lot of natural nuclear shelters in the US that are absolutely free.
All you need to do is to identify the closest one to your home and maybe include it into your bug out plan in case a nuclear war is looming (or an asteroid impact).
Keep in mind that these bunkers are all naturally EMP hardened. But they will protect you only from the nuclear blast and the initial radiation burst.
Sometimes the shelter is so close that is right below your feet. It’s the case in Detroit, where just 1200 Feet below there is a salt mine that can easily shelter the entire population of Detroit! Actually it can shelter over 5 million people.