? A nuclear power plant was built before the bombs. It's main purpose was to generate bomb material, but they definitely showed the principle worked and powered a lightbulb with it.
I was making a rhetorical point, but it works if you switch out 'theoretically' with 'actually', and 'two weeks before' with 'while the first nuclear reactor was supercritical in Chicago'.
I'm pretty certain that the practicality of a nuclear chain reaction wasn't widely accepted in December of 1942, even though fission was first demonstrated by Meitner and Hahn three years before.
