TheChosen1
Moving Target
13 had a geothermal reactor and a nuclear for backup. All vaults had a nuclear one, some made use of thermal.
Isn't Cheyenne Mountain and The Svalbard Global Seed Vault basically Fallout Vaults in real life anyway?
I believe a vault's primary power source was geothermal? Or was that only vault zero. The food processing system was never really defined very well though. Entertainment was provided at vaults because that was part of the grand social experiment.