What is meant by nuclear fission? The fission of one nucleus of U^235 produces 200 MeV of energy. A reactor is generating 4 megawatts of power. How many nuclei are being fissioned per second in the reactor? What is meant by nuclear fission? The fission of one nucleus of U^235 produces 200 mega electron volts of energy. A reactor is generating 4 megawatts of power. How many nuclei are being fissioned per second in the reactor? #studywithyogi #class12th #physicsclass12 #physicsclass12th