I can't think of any fuel source that will satisfy virtually all energy use cases with so little risk as nuclear batterization, even when considering the potent

I can't think of any fuel source that will satisfy virtually all energy use cases with so little risk as nuclear batterization, even when considering the potential ability to lose the knowledge of how to maintain them given a total societal collapse. What other types of fuel are Armageddon proof? Certainly not coal, CNG, whale blubber, solar, etc......Fire maybe? Even then, might as well consider that the end of civilization regardless.......