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Nuclear energy

Nuclear power plants: what they are, how they work, parts and types

Nuclear power plants: what they are, how they work, parts and types

A nuclear power plant is a thermal power plant whose energy source is nuclear energy.

Its operation is similar to that of any other thermal power plant: thermal energy is generated from an energy source to drive a steam turbine connected to an electrical generator.

Nuclear power plants are key facilities in the world of energy, playing an essential role in the production of electricity. In this article, we will explain what nuclear power plants are, their purpose, how they work, and the most common types of nuclear power plants.

What's a nuclear center?

A nuclear power plant, also known as a nuclear power plant, is a facility designed to generate electricity from the energy released during the process of nuclear fission.

Nuclear fission involves splitting heavy atomic nuclei, such as uranium-235, into smaller fragments by colliding with neutrons. This process releases a large amount of energy in the form of heat, which is then converted into electricity.

What is a nuclear power plant used for?

Nuclear power plants: what they are, how they work, parts and typesThe main purpose of a nuclear power plant is to produce electricity efficiently and continuously. Through the process of nuclear fission, these facilities generate heat that is used to produce steam, which then drives turbines connected to electrical generators to generate electricity.

Other purposes of nuclear plants is the reduction of greenhouse gas emissions. Nuclear power plants emit very low amounts of carbon dioxide (CO 2 ) during the generation of electricity compared to power plants that burn fossil fuels such as coal and natural gas.

In addition to electricity generation, some nuclear power plants are used for scientific and medical research. For example, they produce radioactive isotopes used in medicine for the diagnosis and treatment of diseases, as well as for research in nuclear physics.

Parts of a nuclear power plant

Nuclear power plants consist of multiple essential components, including:

  1. Nuclear Reactor: Where nuclear fission takes place, including fuel rods, moderator, and coolant.

  2. Steam generator: With pipes, valves and a turbine to convert heat into steam and electricity.

  3. Electric generator: With a generator and often a transformer to convert mechanical energy into electricity.

  4. Control and safety system: Monitors and regulates the nuclear reaction and guarantees the safety of the facility.

  5. Radioactive waste storage: Including temporary storage pools and plans for the long-term management of radioactive waste.

  6. Containment structures: To guarantee safety and prevent the release of radioactive materials in the event of an accident.

How does a nuclear plant work?

The operation of a nuclear power plant is a highly specialized process that involves the conversion of nuclear energy into electricity in an efficient and controlled manner. This is achieved through a series of interconnected steps that we explain below:

What is a nuclear power plant? Utility and operation

Fission of the uranium atom

The process begins in the core of the nuclear reactor, where the heart of the plant is located. In this core are fuel rods, usually made of enriched uranium or plutonium.

This is where nuclear fission takes place, a process in which the nuclei of heavy atoms split into smaller fragments when bombarded with neutrons. This fission releases a massive amount of heat and more neutrons.

Steam generation

The heat generated by nuclear fission is the key component for the generation of electricity. This heat is transferred to a cooling system, usually using water, to prevent the reactor from overheating. The water turns to steam due to the intense heat, and this high-pressure steam is directed towards a steam generator.

The steam generator is a crucial component in the process. Inside, the hot water steam passes through pipes and valves that take it to a turbine. 

Turbines and electric generator

The turbine, which is connected to an electric generator, harnesses the kinetic energy of the moving steam and converts it into mechanical energy. The turbine rotates at high speed, which causes the electric generator to produce electricity.

Steam condensation

The cycle does not end here. The exhausted steam, after passing through the turbine, is cooled and condensed back into water.

This condensation process is completed in a cooling system, and the resulting water is returned to the reactor core to start the cycle all over again.

Repeat cycle

This cycle of heating, steam generation, turbine drive, and electricity production is constantly repeated to maintain a constant supply of electrical power.

In addition, control and security systems are implemented to monitor and regulate the nuclear reaction, guaranteeing the safe operation of the plant.

Types of nuclear reactors

There are different types of nuclear reactors, all fission. The UN classifies them as follows:

  • The pressurized water reactor (PWR and VVER). They use high pressure water to produce steam for steam generators. They have three circuits.

  • The Boiling Water Reactor (BWR): The second most common in the world. The water boils, generating steam directly in the reactor core. They have only two circuits.

  • Pressurized Heavy Water Reactor (PHWR): Uses high-pressure heavy water as a neutron moderator and coolant.

  • The gas-cooled reactor (GCR: AGR and Magnox): They use graphite as a neutron moderator and gaseous carbon dioxide as a coolant.

  • The light water-cooled, graphite-moderated reactor (LGR and RBMK): Models of Russian origin. "Light water" is normal water.

  • The fast reactor (LBR, or LMFBR): It does not slow down the neutrons of the chain reaction and cools with liquid sodium. They are in the prototype and research phase.

  • Molten salt reactors: They are a developing technology that uses a mixture of molten salt as coolant and fuel.

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Publication Date: December 10, 2009
Last Revision: September 15, 2020