Nuclear reactors are the heart of nuclear power plants, where the process of nuclear fission is harnessed to generate electricity. There are various types of reactors, but two common designs are pressurized water reactors (PWRs) and boiling water reactors (BWRs).

In a PWR, the nuclear fission process heats the water in the reactor core. This hot pressurized water then flows through a heat exchanger called the steam generator, where it transfers its heat to a separate water loop. The secondary water loop turns into high-pressure steam which drives a turbine, generating electricity. The condensed steam is then returned to the steam generator to be heated again.

BWRs, on the other hand, accomplish both the generation of steam and the production of electricity within the same vessel. The heat generated from the nuclear fission process directly boils the water in the reactor core, producing steam. This steam is then used to drive the turbine, generating electrical power.

When operating at full capacity, nuclear reactors can produce a large amount of electricity consistently over a long period of time. A single nuclear reactor can provide power to thousands of homes and businesses.