Nuclear reactors generate energy through the process of nuclear fission, utilizing the heat produced to create steam that drives turbines, ultimately generating electricity.

In a nuclear reactor, nuclear fission is meticulously controlled to sustain a chain reaction. The primary fuels used in most reactors are uranium-235 and plutonium-239—both heavy and unstable isotopes. When a neutron collides with the nucleus of one of these atoms, it induces the nucleus to split, releasing a substantial amount of energy in the form of heat. This phenomenon is known as fission.

The fission of a single atom not only releases energy but also emits additional neutrons. These newly released neutrons can trigger the fission of surrounding atoms, thereby perpetuating a chain reaction. To ensure that this chain reaction remains stable—neither accelerating too quickly nor decelerating too much—reactors employ control rods made from materials that absorb neutrons, such as boron or cadmium. By adjusting the positioning of these control rods, operators can effectively manage the rate of the fission reaction, and consequently, the amount of heat generated.

The heat produced from the fission process is utilized to heat water, resulting in steam production. This steam then drives turbines connected to electrical generators. As the turbines rotate, they spin the generators, thereby producing electricity. This method is fundamentally similar to that employed in other power plants, such as coal or gas-fired facilities, although the source of heat differs.

It is important to note that the nuclear fission process generates radioactive waste, which requires careful management and disposal. This presents a significant challenge associated with nuclear energy. Nonetheless, nuclear power is recognized as a low-carbon energy source, as the fission process does not emit greenhouse gases, unlike the combustion of fossil fuels.

In summary, nuclear reactors convert energy from fission into heat through the controlled management of a nuclear chain reaction. This heat is then transformed into steam, which drives turbines to generate electricity.