The liberated thermal energy is used to heat water at high pressure and high temperature until it becomes steam. This steam spins a turbine connected to a generator which transforms the mechanic energy of the turbine spins into electric energy. It is important to keep in mind that in nuclear fission the nuclei of heavy atoms are bombarded with neutrons and then decompose into smaller and lighter nuclei. When this happens they release the energy that binds the neutrons and protons that compose them, and then they emit two or three neutrons.
These can produce more fissions as they interact with new heavy nuclei, which will then emit new neutrons and so on, so that the reaction sustains itself. This multiplying effect is known as nuclear fission chain reaction.
The water is then transported to the new steam generator to become steam again inside a closed circuit. It was previously indicated that a nuclear reactor is a site that can initiate, sustain and stop nuclear fission chain reactions in a controlled way, with the adequate means to extract the generated heat.
The central component of a nuclear power plant is the reactor, the site that houses the nuclear fuel. With more than commercial reactors worldwide , including 94 in the United States, nuclear power continues to be one of the largest sources of reliable carbon-free electricity available. The main job of a reactor is to house and control nuclear fission —a process where atoms split and release energy.
Reactors use uranium for nuclear fuel. The uranium is processed into small ceramic pellets and stacked together into sealed metal tubes called fuel rods. Typically more than of these rods are bundled together to form a fuel assembly. A reactor core is typically made up of a couple hundred assemblies, depending on power level.
Inside the reactor vessel, the fuel rods are immersed in water which acts as both a coolant and moderator. The moderator helps slow down the neutrons produced by fission to sustain the chain reaction. Like any industry, the nuclear industry generates waste. However, unlike many industries, nuclear power generates very little of it — and fully contains and manages what it does produce.
The vast majority of the waste from nuclear power plants is not very radioactive and for many decades has been responsibly managed and disposed of. The used fuel which comes out of the reactor can be managed in different ways, including recycling for energy production or direct disposal. As a matter of fact, many countries have been using recycled fuel for decades to partially fuel their reactors. How does a nuclear reactor work?
A reactor being refuelled Image: Vattenfall What fuels a reactor? 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. As of December 31, , 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.
Learn more about the U. The United States had the largest nuclear electricity generation capacity and generated more nuclear electricity than any other country. Nuclear explained Nuclear power plants. What is energy? Units and calculators.
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