In a nuclear power plant, the heat input is generated by what?

• A. Nuclear fuel in the reactor
• B. Coal combustion
• C. Natural gas combustion
• D. Solar collectors

Answer: (A)

Heat input in a nuclear power plant comes from nuclear fission of fuel inside the reactor core. When fissile nuclei (like U-235 or Pu-239) split, they release a large amount of energy as heat, which is absorbed by the reactor coolant to transfer this energy into the steam cycle. The rate of this heat production is controlled by the reactor’s fuel, moderator, and control rods to keep the plant operating safely and steadily. The other options describe fuels used in fossil-fueled or solar plants, not the source of heat for a nuclear reactor.