Here's the answer, Bethesda. If something doesn't make sense in their Fallout games, it's Bethesda. Remember how in Fallout 3 that the Brotherhood made base in the Pentagon, well where did they get the food and water and other resources? They were fighting the Super mutant threat in Washington and they were magically surviving on air?
Here's a post on Steam that illustrates the lack of common sense Bethesda has with their Fallout games.
https://steamcommunity.com/app/377160/discussions/0/458606877310719380/
And here's Pete Hines admitting they don't care about lore or consistency.
https://twitter.com/DCDeacon/status/668802348140109824