# Nuclear Reactors

The tiny nucleus of an atom holds a lot of energy. Just one kilogram of uranium-235 can give two to three million times more power than a kilogram of coal! Nuclear reactors have some benefits over non-renewable sources of energy. Yes, the radioactive waste they produce is dangerous, but it eventually turns into safe stuff like lead. Plus, nuclear fuels like uranium make less waste than fossil fuels. And while or wind power are green, they can't produce as much energy as nuclear power, and they rely on good weather. If we can make nuclear reactors safer and better, we could stop using up our limited fossil fuel supplies. Keywords: Nuclear Reactors, non-renewable energy, renewable energy, radioactive waste, uranium.

## Nuclear Reactor Explanation and Fundamentals

The nuclear reactor is the core of a nuclear power plant. It works in a similar way to a coal power plant, creating electricity by heating and boiling water. The energy from the nuclear reactions inside the reactor produces steam that spins a turbine to make electricity. The steam is cooled and reused in the reactor. There are two ways to heat the water: nuclear fission and nuclear fusion. In fission, a parent nucleus is split into two daughter nuclei, releasing energy. In fusion, two light nuclei are combined, and the leftover mass is released as energy. To calculate how much energy is released, we use Einstein's equation, which shows how mass can be turned into energy. Keywords: Nuclear Reactor, electricity, nuclear fission, nuclear fusion, Einstein's equation.

## Nuclear Fission

In nuclear fission, we split a parent nucleus to make two daughter nuclei. The difference in mass between the two is turned directly into energy. Uranium-235 is the most common fuel for fission reactors, but splitting just one atom releases a tiny amount of energy. A typical UK home needs millions of times more energy per year. Luckily, there are many uranium-235 atoms in just one kilogram of uranium. But how do we split more than one nucleus at a time? The answer is nuclear chain reactions. Keywords: Nuclear fission, Uranium-235, energy, nuclear chain reactions.

When a neutron is absorbed by a Uranium-235 isotope inside a nuclear fission reactor, it briefly becomes Uranium-236. This is highly unstable and quickly decays into two daughter nuclei, Caesium-140 and Rubidium-92, releasing a significant amount of energy. Additionally, two or three neutrons are also emitted during the process. If these neutrons are absorbed by other U-235 isotopes, further nuclear fission reactions occur, releasing even more energy. This is known as a nuclear chain reaction. If uncontrolled, a chain reaction can release an enormous amount of energy in a very short time, as seen in nuclear weapons. However, in a nuclear power plant, the reaction is regulated to control the amount of energy released. Keywords: Nuclear fission, Uranium-235, nuclear chain reaction, energy, regulation.

### Nuclear Fission Reactor Diagram

To understand how to control a nuclear chain reaction for use in our powerplants, we should study the design of a nuclear fission reactor. A fission reactor has mechanisms engineered to moderate a chain reaction so that we can extract the exact amount of energy desired. This is particularly useful as the UK's energy demands on the national grid change based on many different factors, including the time of day, weather, season and so on[1].

The University of California, Berkeley offers a study in fission reactor design which encompasses the synthesis of the basic components of nuclear technology in the engineering and design of nuclear reactors The Department of Energy provides an overview of how nuclear reactors work, including the physical process of fission and how heat is used to create electricity. The International Atomic Energy Agency (IAEA) also provides information on the design of nuclear power plants and the importance of safety assessments. Finally, the U.S. Department of Energy's Advanced Reactor Demonstration Program (ARDP) is designed to help domestic nuclear industry demonstrate their advanced reactor designs on accelerated timelines.

A nuclear fission reactor contains several important parts. The nuclear fuel source, such as uranium, plutonium, or thorium, is held in fuel rods encased with a graphite moderator. The moderator slows down any emitted neutrons, making them more likely to be absorbed by the nuclear fuel in another rod, inducing a higher rate of nuclear fission.

Control rods are the primary mechanism for controlling the rate of the nuclear chain reaction inside the fission reactor. They are typically made of elements like silver or boron, which readily absorb neutrons without splitting themselves. The rate of the nuclear chain reaction can be controlled by raising or lowering the control rods. Lowering the control rods further into the core slows the reaction rate, while removing them increases it. Multiple control rods allow for real-time control of the fission process.

Radiation shielding, usually made of concrete, is used to protect the external environment from the radioactive and harmful daughter products of the fission reactions. The energy generated by nuclear fission in the reactor heats water, producing steam that turns a steam turbine, which generates electricity for use.

## Nuclear Fusion

Nuclear fusion is a process where two atomic nuclei are combined into one nucleus, releasing energy as a result of the difference in mass before and after the reaction. Nuclear fusion powers our Sun, where countless fusion reactions occur every second. This process can generate immense amounts of energy, several times greater than fission, and the fuel used in fusion is abundant and cheap, unlike heavier, radioactive elements used in fission. Additionally, none of the products of fusion are themselves radioactive, making nuclear fusion a green and renewable energy source.

Despite the many benefits of nuclear fusion, there are currently no nuclear fusion reactors in the world. The main challenge in achieving nuclear fusion is overcoming the repelling force between two positively charged atomic nuclei. To do this, an environment with extremely high temperature and pressure is needed, similar to that found inside a star. Scientists and engineers are currently working to develop fusion reactors, but it is a difficult and costly process.

There are two main approaches to achieving nuclear fusion: magnetic confinement and inertial confinement. Magnetic confinement involves using powerful magnetic fields to contain and compress a plasma made of deuterium and tritium, two isotopes of hydrogen. Inertial confinement involves using lasers to rapidly compress and heat a tiny pellet of deuterium and tritium, causing fusion to occur. Both approaches have their own unique challenges and require significant technological advancements to become viable sources of energy.

Despite the challenges, nuclear fusion has the potential to revolutionize the way we generate energy, providing a clean and abundant source of power for generations to come.

One of the main challenges in achieving nuclear fusion is the amount of energy needed to sustain the reaction. Currently, the energy required to create the necessary environment for fusion is greater than the energy we receive from the fusion process itself. However, scientists and engineers have been making steady progress in overcoming this problem over the past few decades.

In any future nuclear fusion reactor, deuterium and tritium are likely to be used as fuel. These two hydrogen isotopes can fuse at lower temperatures than other sources and release more energy than many other fusion reactions. Additionally, deuterium is easily found in seawater and tritium can be artificially produced easily and cheaply.

Deuterium nuclei contain one proton and one neutron each, while tritium contains one proton and two neutrons each. When deuterium and tritium undergo fusion, they merge into an ordinary helium nucleus, releasing a single neutron and a large amount of useful energy. This process is much cleaner and safer than nuclear fission, as there are no radioactive byproducts produced during the fusion reaction.

In order to achieve fusion, the fuel must be heated to millions of degrees Celsius, which causes it to become a plasma. The plasma must then be confined and compressed to create the necessary conditions for fusion to occur. Scientists and engineers are currently exploring different methods of plasma confinement, such as magnetic confinement and inertial confinement, to achieve sustainable nuclear fusion.

Nuclear Reactors - Key takeaways Immense amounts of energy are contained within the nuclei of atoms that we can utilise in power generation. Nuclear Powerplants produce less waste than fossil fuels and the radioactive waste does eventually decay into harmless substances. Plus they can generate far more electricity than renewable energy sources like solar, wind or tidal power. The energy released during a nuclear reaction is used to heat water like other types of power plants. The heated water turns into steam, which uses mechanical work to spin a turbine. The turbine ultimately generates electricity. The steam can then be cooled in a condenser to be reused in the reactor. In nuclear fission, one heavier atomic nuclei is split apart into two daughter nuclei. The total mass of the daughter nuclei is always less than the parent nucleus. The mass difference is converted into energy. In nuclear fusion, two light atomic nuclei are forced together to merge into a single nucleus. The mass of the resultant nucleus is always less than the original two nuclei. The mass difference is converted into energy. Nuclear chain reactions are used to split more than one atom at a time. Uncontrolled chain reactions are used in weapons and controlled chain reactions are used in nuclear power plants. Nuclear fission reactors have many important parts. Fuel rods, control rods, graphite moderator and radiation shielding. Nuclear fusion can produce several times more energy than nuclear fission. Fuel is abundant and cheap and the process produces no radioactive waste. Fusion power plants are also safer than fission power plants. Nuclear fusion requires a high temperature and pressure environment to overcome the repelling force between the two positive nuclei.

## Nuclear Reactors

How does a nuclear reactor work?

A nuclear fission reactor splits heavy atomic nuclei in a process called nuclear fission. Splitting these nuclei causes a nuclear chain reaction which releases a lot of energy.

What is a nuclear reactor?

A nuclear reactor is the part of a nuclear power plant that is used to heat and boil water using nuclear reactions.

What are the two types of nuclear reactors?

Nuclear Fission Reactor, where atomic nuclei are split to release energy.Nuclear Fusion Reactor, where atomic nuclei are forced together to release energy.

What are the fundamentals of a nuclear reactor?

A nuclear reactor uses nuclear reactions to release energy. One of the primary purposes of the reactor is to moderate these reactions using control rods, so that the exact amount of energy is desired.

What is an example of a nuclear reactor?

Fukushima (Japan), Chernobyl (Ukraine), Torness (UK)

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