What is the fuel in nuclear power plants and how is it used to generate electricity?

• A. Water is the fuel and it splits into gas
• B. Uranium-235 is the fuel and it splits into Neon
• C. Uranium-238 is the fuel and it is split into Plutonium when a neutron splits the atom
• D. Plutonium is the fuel and it fuses with neutrons

Answer: (C)

The key idea is that nuclear power uses fission of a fissile fuel to produce heat, which then drives electricity generation. In most plants, the fuel is uranium-235. When a neutron strikes a U-235 nucleus, it splits into smaller fragments and releases a large amount of energy plus more neutrons. Those neutrons keep the reaction going in a controlled way, a chain reaction. The energy released as heat in the reactor core is transferred to water, producing high‑pressure steam that turns turbines connected to generators, making electricity.

Water isn’t the fuel—it's the coolant and moderator that help manage the reaction and carry away the heat. Uranium-238 isn’t the primary fuel in typical reactors; it’s more abundant but not readily fissile with slow neutrons, though it can breed plutonium-239 in some designs. Plutonium can be used in certain fuel mixes, but electricity comes from fission, not fusion.