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How Is Nuclear Energy Powered?

Nuclear power comes from nuclear fission Nuclear power plants heat water to produce steam. The steam is used to spin large turbines that generate electricity. Nuclear power plants use heat produced during nuclear fission to heat water. In nuclear fission, atoms are split apart to form smaller atoms, releasing energy.6 Apr 2021
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Nuclear power comes from nuclear fission

Nuclear power plants heat water to produce steam. The steam is used to spin large turbines that generate electricity. Nuclear power plants use heat produced during nuclear fission to heat water.

In nuclear fission, atoms are split apart to form smaller atoms, releasing energy. fission takes place inside the reactor of a nuclear power plant. At the center of the reactor is the core, which contains uranium fuel.

The uranium fuel is formed into ceramic pellets. Each ceramic pellet produces about the same amount of energy as 150 gallons of oil. These energy-rich pellets are stacked end-to-end in 12-foot metal fuel rods. A bundle of fuel rods, some with hundreds of rods, is called a fuel assembly. A reactor core contains many fuel assemblies.

The heat produced during nuclear fission in the reactor core is used to boil water into steam, which turns the blades of a steam turbine. As the turbine blades turn, they drive generators that make electricity. Nuclear plants cool the steam back into water in a separate structure at the power plant called a cooling tower, or they use water from ponds, rivers, or the ocean. The cooled water is then reused to produce steam.

Nuclear reactors in the United States may have large concrete domes covering the reactors, which are required to contain accidental releases of radiation. Not all nuclear power plants have cooling towers. Some nuclear power plants use water from lakes, rivers, or the ocean for cooling.

Containment dome of a nuclear reactor

Source: Stock photography (copyrighted)

Nuclear power plants have generated about 20% of U.S. electricity since 1990

As of December 31, 2020, 94 nuclear reactors were operating at 56 nuclear power plants in 28 states. Thirty-two of the plants have two reactors, and three plants have three reactors. Nuclear power plants have supplied about 20% of total annual U.S. electricity since 1990. Learn more about the U.S. nuclear energy industry.

The United States generates more nuclear power than any other country

In 2019, 31 countries had commercial nuclear power plants, and in 14 of the countries, nuclear energy supplied at least 20% of their total annual electricity generation. The United States had the largest nuclear electricity generation capacity and generated more nuclear electricity than any other country. France, with the second-largest nuclear electricity generation capacity and second-highest nuclear electricity generation, had the largest share—about 70%—of total annual electricity generation from nuclear energy.

Top five nuclear electricity generation countries, 2019

CountryNuclear electricity generation capacity (million kilowatts)Nuclear electricity generation (billion kilowatthours)Nuclear share of country's total electricity generation United States 98.12 809.41 19% France 63.13 382.40 70% China 45.52 330.12 5% Russia 28.37 195.54 18% South Korea 23.09 138.81 25%Source: U.S. Energy Information Administration, International Energy Statistics, as of March 24, 2021

Last updated: April 6, 2021

14 Related questions Answers found

Does nuclear energy need electricity?

Nuclear is a zero-emission clean energy source. It generates power through fission, which is the process of splitting uranium atoms to produce energy. The heat released by fission is used to create steam that spins a turbine to generate electricity without the harmful byproducts emitted by fossil fuels.

Why is nuclear energy not green?

The mining, milling and enrichment of uranium into nuclear fuel are extremely energy-intensive and result in the emission of carbon dioxide into the atmosphere from the burning of fossil fuels.

Is nuclear the cleanest energy?

Based on safety and carbon emissions, fossil fuels are the dirtiest and most dangerous, while nuclear and modern renewable energy sources are vastly safer and cleaner.

Can solar replace nuclear?

Today, variable sources like wind and solar are not a one-to-one replacement for firm capacity like nuclear. They might be someday soon, with help from batteries, but in the short term, the time horizon of these nuclear retirements, they are not. That means more natural gas.

How does nuclear power affect the environment?

Nuclear energy produces radioactive waste A major environmental concern related to nuclear power is the creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes. These materials can remain radioactive and dangerous to human health for thousands of years.

Is nuclear energy expensive?

Nuclear power plants are expensive to build but relatively cheap to run. In many places, nuclear energy is competitive with fossil fuels as a means of electricity generation. Waste disposal and decommissioning costs are usually fully included in the operating costs.

Why don't we run on nuclear energy?

Barriers to and risks associated with an increasing use of nuclear energy include operational risks and the associated safety concerns, uranium mining risks, financial and regulatory risks, unresolved waste management issues, nuclear weapons proliferation concerns, and adverse public opinion.

What do you need for nuclear energy?

Uranium is the fuel most widely used to produce nuclear energy. That's because uranium atoms split apart relatively easily. Uranium is also a very common element, found in rocks all over the world. However, the specific type of uranium used to produce nuclear energy, called U-235, is rare.

How efficient is nuclear energy?

Nuclear plants are the most efficient source of electricity, operating 24/7 at a 93 percent average capacity factor. (Capacity factor is the ratio of the actual amount of electricity generated by a plant compared to the maximum amount that it could potentially generate.)

Why is nuclear energy so powerful?

Unlike other traditional energy sources such as solar or wind power, nuclear energy can be produced in any condition because it is created in a nuclear power plant that seldom needs to be shut down for maintenance. This provides a steady and efficient supply of powerful energy.

Is nuclear energy green?

By many definitions, nuclear energy is not renewable. But in terms of climate change, nuclear energy production does not release greenhouse gases, so it is a low-carbon fuel.

Why is nuclear energy better than renewable?

Nuclear power releases less radiation into the environment than any other major energy source. Second, nuclear power plants operate at much higher capacity factors than renewable energy sources or fossil fuels. Capacity factor is a measure of what percentage of the time a power plant actually produces energy.

Is nuclear energy increasing or decreasing?

The amount of energy consumption that is in the form of electricity increases from about 20% today to about 50% by 2050. Whilst absolute supply from nuclear increases, its relative contribution to the electricity mix decreases from about 10.5% in 2020 to about 8% in 2050.

What is the cleanest energy source?

Out of all energy resources, we consider green power (solar, wind, biomass and geothermal) as the cleanest form of energy. So, if we were looking at clean energy on a spectrum, these would be farthest from “dirty” or emissions-heavy energy.