What Is Nuclear Reactor, How Does It Work?

What Is Nuclear Reactor?

In this article we will discuss about What Is Nuclear Reactor & How Does It Work? A nuclear reactor, also known as an atomic pile, is a device that is used to start and control a fission nuclear chain reaction or a nuclear fusion reaction. Nuclear reactors are used in nuclear power plants to generate electricity as well as in nuclear marine propulsion.

The heat generated by nuclear fission is transferred to a working fluid (water or gas), which then drives steam turbines. These either move a ship’s propellers or turn the shafts of electricity generators. In theory, nuclear-generated steam can be utilised for industrial process heat or district heating.

Some reactors create isotopes for medicinal and industrial purposes, while others produce weapons-grade plutonium.

How Does A Nuclear Reactor Work?

Nuclear reactors are essentially huge kettles that heat water to generate massive volumes of low-carbon power. They come in a variety of sizes and shapes and are powered by a selection of different fuels.

A nuclear reactor is powered by the fission of atoms, which occurs when a particle (a ‘neutron’) is fired at an atom, which subsequently fissions into two smaller atoms and some extra neutrons. Some of the neutrons released then collide with other atoms, causing them to fission and emit more neutrons. This is thought to as a chain reaction.

The chain reaction’s fissioning of atoms releases a tremendous quantity of energy as heat. The created heat is removed from the reactor by a circulating fluid, usually water. This heat can then be utilised to make steam, which powers turbines and generates energy.

Reactors have systems that accelerate, halt, or shut down the nuclear reaction and the heat it creates to guarantee that it occurs at the correct speed. Control rods, which are typically comprised of neutron-absorbing materials like as silver and boron, are typically used for this.

Nuclear reactors exist in a variety of shapes and sizes, with some using water to cool their cores and others using gas or liquid metal. Water is used in the most popular forms of power reactors, accounting for more than 90% of the world’s reactors.

Further information on the many different types of reactors found around the world may be found in the Information Library’s Nuclear Power Reactors section. Nuclear reactors are extremely reliable in generating power, capable of running continuously for months, if not years, regardless of weather or season.

Furthermore, most nuclear reactors can operate for very long periods of time, often exceeding 60 years. Units 3&4 of the Turkey Point plant in Florida were the world’s first reactors to be licenced for 80 years of operation in 2019.

In this article we will discuss about What Is Nuclear Reactor & How Does It Work?

What Fuels A Reactor?

Uranium is the most widely used material for powering reactors, while other substances can also be used.
The oceans are just one of the many settings where uranium is prevalent. Other fuels, like as plutonium and thorium, are also viable options.

Most modern reactors have several hundred fuel assemblies, each with thousands of tiny uranium pellets. A single pellet contains the same amount of energy as one tonne of coal. Every year, a typical reactor requires approximately 27 tonnes of new fuel. To create the same amount of electricity, a coal power plant of comparable scale would need to burn more than 2.5 million tonnes of coal.

How About The Waste?

The nuclear business, like any other, generates waste. Unlike many sectors, however, nuclear power generates very little of it and thoroughly confines and manages what it does produce. The vast majority of nuclear power plant waste is not radioactive and has been appropriately managed and disposed of for many decades.

If nuclear power was used to meet a person’s electrical needs for an entire year, just about 5 grammes of highly radioactive waste (the same weight as a sheet of paper) would be created. The spent fuel from the reactor can be managed in a variety of ways, including recycling for energy production or direct disposal.

Indeed, many countries have been using recycled fuel to partially feed their reactors for decades.

Types Of Light-Water Reactors In The United States

Light-water reactors are used in all commercial nuclear reactors in the United States. This implies they employ ordinary water as a coolant as well as a neutron moderator.

In the United States, there are two types of light-water reactors in operation.

1. Pressurized Water Reactors

Pressurized-water reactors, often known as PWRs, make up around 65% of commercial reactors in the US. To prevent the water from boiling, these reactors inject high-pressure water into the reactor core.

Nuclear fission heats the water in the core, which is then circulated through tubes within a heat exchanger. To generate steam, the tubes heat a separate water source. The steam then powers an electric generator, which generates electricity.

2. Boiling Water Reactors

Boiling water reactors account for roughly one-third of all reactors in operation in the United States (BWRs).

BWRs generate steam and heat water directly inside the reactor vessel. When water is pumped up through the reactor core, it is heated by fission. Pipes then carry the steam directly to a turbine, which generates power.

New Nuclear Reactor Technology

Innovative entrepreneurs and startups are creating new types of reactors that are more efficient and flexible in operation, can reach rural and developing places, and can even convert seawater into drinking water.

Advanced reactors encompass several different types of reactors, including small modular reactors (SMRs), which are currently in development. Several of these novel designs do not use water to cool; instead, they use materials such as liquid metal, molten salt, or helium to transfer heat to a separate supply of water and produce steam.
SMRs are advanced reactors that produce no more than 300 megawatts of power. They will be less expensive to build and can be constructed in factories and sent to where they are required, allowing them to provide carbon-free electricity to rural places or underdeveloped nations. SMRs can also scale their power output to match peak demand, making them suitable partners for intermittent renewable energy sources.
Some advanced reactors will operate at higher or lower temperatures or pressures than standard nuclear reactors. They will also provide other uses such as water desalination and hydrogen manufacturing. Other reactors will be very fuel efficient since they will generate less waste or have longer fuel cycles and will not need to halt and refill for a decade or more.