Different Types of Nuclear Reactors and Power Plants

Nuclear reactors generate energy using one of two types of nuclear reactions: fission or fusion. Currently, there are no commercial fusion reactors around the globe because scientists have not yet discovered how to maintain the required temperatures long enough to generate net power.

There several different types of nuclear reactors, including:

Pressurized water reactors (PWRs)
Boiling water reactors (BWRs)
Heavy water reactors (HWRs)
Advanced gas-cooled reactors (AGRs)
Magnetic confinement fusion (MCF)
Inertial confinement fusion (ICF)

Fusion vs fission reactions

Fusion occurs when two atoms fuse together. Nuclear fusion releases an enormous amount of energy. Fusion does not create any long-lived radioactive waste.
Fission occurs when one atom is ripped apart. This process creates radioactive waste. Fission and fusion both release a great deal of energy, but fusion releases about four times more.

Types of nuclear reactors: fission vs fusion

Within the two types of nuclear reactors, there are several more subcategories.

Fission reactors

Some of the notable fission reactor designs include:

Pressurized water reactors (PWRs)

In PWRs, water acts as both the coolant and moderator. The water is kept under high pressure to prevent boiling, and it transfers heat from the reactor core to a steam generator to produce electricity.

Boiling water reactors (BWRs)

BWRs also use water as both the coolant and moderator. In this design, the water is allowed to boil directly in the reactor core, producing steam that drives the turbine to generate electricity.

Heavy water reactors (HWRs)

HWRs use heavy water, which contains a higher concentration of deuterium, as both the coolant and moderator. Heavy water reactors can utilize natural uranium as fuel and are known for their efficient use of resources.

Advanced gas-cooled reactors (AGRs)

AGRs use carbon dioxide gas as the coolant and graphite as the moderator. This design is primarily employed in the United Kingdom and is known for its high thermal efficiency.

Fusion reactors

Two main approaches to achieving fusion reactions are:

Magnetic confinement fusion (MCF)

MCF uses strong magnetic fields to confine and control a hot plasma of hydrogen isotopes, such as deuterium and tritium. The goal is to achieve conditions where fusion reactions can occur and sustain a self-sustaining plasma state.

Inertial confinement fusion (ICF)

ICF involves rapidly compressing and heating fuel pellets using powerful lasers or particle beams. The intense pressure and temperature cause the fuel to undergo fusion reactions. ICF is primarily being explored for its potential use in thermonuclear weapons and as a stepping stone toward achieving practical fusion power.

Learn more about nuclear energy

Written by Graham Lumley

Graham Lumley is Growth Product Manager at BKV Energy, a retail electricity provider in Texas' deregulated market, where he has worked since 2023. He analyzes customer usage and billing data, helps develop BKV's fixed-rate plans, and creates tools to simplify Texas electricity shopping. He has written over 200 articles on Texas electricity rates, delivery charges, plan types, energy generation, and more to help Texans understand their bills and pay less. With over 10 years of experience in consumer, marketing, and energy, he explains the Texas electricity market in plain language.