Nuclear Reactors

how the nuclear reactor can work?

A nuclear reactor is a system which generates a nuclear fission reaction. A nuclear reaction is a self-sustaining reaction where the output of one stage is the input of the next stage. Therefore, if there is enough fuel, the reaction will continue indefinitely.

The most common type of fission reaction is a Uranium 236 reaction. Nuclear fission involves splitting an atom into smaller atom(s). In a U236 reaction, Uranium 235 is the fuel. A neutron is propelled, which strikes the nucleus of a Uranium 235 atom, creating a U236 atom. U236 is highly unstable, and undergoes radioactive decay. This means the U235 atom turns into a Krypton atom, and a Barium atom, plus 2 extra neutrons and some energy. This energy is generally heat, and is absorbed by nearby water, which boils and turns a turbine.

The two neutrons continue the reaction by hitting another U235 atom (each).

There are other types of nuclear reactions as well, but the principle is the same. The output is generally atoms of different atomic mass, energy, and some other byproduct which will continue the reaction (e.g. an alpha particle - a Helium nucleus, or a neutron). In nuclear fission, the atom byproducts have a lower atomic mass.

In nuclear fusion, the atom byproducts have a higher atomic mass (since multiple atoms are fused together). Nuclear fusion is the basic power plant in the core of the sun (combining Hydrogen atoms into Helium, or Helium into Carbon, etc.). The byproduct here is the energy that we see as light.

Slow neutron fission chain reaction.

Most reactors use uranium fuel enriched slightly to about 3-4 percent U-235, in the form of uranium dioxide UO2. Some older reactors used metallic natural uranium, while some other reactors use plutonium or a plutonium-uranium mix as fuel.

Plasma is highly ionized atoms. This results in extremely energetic ions, and these ions carry an electrostatic charge. The tokamak is a container with magnetic fields for boundaries. The plasma is a moving group of electrostatic charges, and moving charges create magnetic fields. The magnetic field thus created interacts with the magnetic field set up in the tokamak to deflect and thus confine the charged plasma.

Nuclear power plants can generate electricity by using nuclear reactions to heat water and produce steam, which then drives turbines to generate electricity. This source of energy is generally considered low-carbon and can help reduce greenhouse gas emissions compared to fossil fuel sources. Additionally, nuclear power can provide a reliable and steady source of electricity, contributing to energy security and grid stability.

The development of nuclear weapons was a collaborative effort by several scientists working on the Manhattan Project during World War II. The key figures involved in this project were J. Robert Oppenheimer, Enrico Fermi, and the physicist Albert Einstein who wrote to President Roosevelt urging the research on nuclear weapons.

As of 2021, India has 22 operational nuclear reactors across seven nuclear power plants. India has plans to increase its nuclear energy capacity through the construction of additional reactors in the coming years.

Nuclear centrifuges are machines used to enrich uranium by separating isotopes. The centrifugal force causes the heavier U-238 isotopes to collect on the outer rim, while the lighter U-235 isotopes concentrate towards the center, allowing for enrichment. This technology is a critical step in the production of nuclear power and nuclear weapons.

Nuclear power creates jobs across various sectors, including engineering, construction, maintenance, operations, research, and support services. Specific job titles may include nuclear engineer, reactor operator, radiation protection technician, and waste management specialist. Additionally, nuclear power plants create indirect jobs in industries such as manufacturing, transportation, and supply chain.

No, the neutrons produced in nuclear reactors don't travel anywhere near the speed of light. Let's look at this a bit. In the "standard" fission reactor, fissile nuclear fuel is "started up" and the neutron chain reaction begins. Neutrons are produced during atomic fission events, and these neutrons are sometimes called "fission energy" or "prompt" or "fast" neutrons. They are the free neutrons that appear as the result of the fission event. And they're moving pretty darn quick when they're "blown out" of the fissioning nucleus. But they're not moving anywhere near the speed of light. The Boltzman distribution (a fancy way of speaking about the range of energies at which the fast neutrons appear), has a strong peak at close to 2 MeV (20 TJ/kg). That translates into a speed of 28,000 km/s. The speed of light is some 299,792 km/s as we've defined it, and that puts the speed of those fast neutrons at roughly 10% the speed of light.

I make it 104 on the NRC website (operating units, that is)

For water reactors the danger would be mainly from the high temperature, escaping water would flash to steam and scald anyone nearby.

CO2 cooled reactors would also present high temperature and risk of asphyxiation.

There might be some radioactivity, but not a huge amount as failed fuel would have been removed before it became high enough to be dangerous.

Of course if a Loss of Coolant (LOCA) occurred resulting in fuel failure, there might be more activity released, but design is aimed at preventing a LOCA, even in extreme cases such as an earthquake.

Uranium is the primary element used in nuclear reactors for energy generation. When uranium atoms undergo nuclear fission, they release a significant amount of energy that can be harnessed for various applications, including electricity generation.

It is used as a moderator. Natural uranium will not undergo nuclear fission by itself because neutrons emitted by fissioning U-235 tend to be absorbed by U-238. However, if the neutrons can be slowed down, it turns out that U-238 is less likely to eat them, and enough are available to fission U-235 and keep the reaction going. Graphite has the useful property that it can slow neutrons down without eating them, so if you embed uranium lumps in a graphite matrix with appropriate spacing, the neutrons which get into the graphite will be slowed down, and when they finally hit a lump of uranium they are likely to be taken up by U-235 and cause fission.

Any light element with a sufficient distaste for neutrons can be used as a moderator. Heavy water (deuterium oxide) works nicely. Natural water has slightly too high an appetite for neutrons to work well, but if the concentration of U-235 is raised a bit, you can make a reactor with natural water moderator. That is how power reactors work in the USA and most other countries.

The cost to run a nuclear reactor can vary depending on factors like the size of the reactor, maintenance requirements, and operating expenses. Generally, it can cost millions to tens of millions of dollars annually to operate a nuclear reactor.

It's all about the nuclear fission byproducts. When fission occurs, a couple of neutrons are produced. But what happened to the rest of the uranium atom? The bulk of its mass remains as fission fragments. The fission fragments are radioactive byproducts of the event, and they in turn have to decay (radioactively) into something that is stable. This can take several transitions, and the decay rates vary from fractions of a second to millions of years. Spent fuel is highly radioactive ("hot"), and it has a variety of long-lived radionuclides in it. Nuclear fuel is seal up (welded inside) cladding to "keep it in one place" when fuel plates or fuel rods are produced. The spent fuel has all this highly radioactive and nasty-as-heck stuff inside the fuel plates or fuel rods. The radioactive byproducts are radioactive (and highly so!) for a long, long, long time. Aside from the possibility of radioactive contamination that might occur in a nuclear accident, the long-term storage of spent fuel is a major headache. The length of time it will take for the stuff to "cool off" radioactively, once the (fairly simple) physics of radioactive decay is comprehended, will leave the understanding person ill. Use the link to the Wikipedia article on long-lived fission products and skim it. Note what is produced and the half-lives of the stuff. It's disconcerting.

The United States was the first country to use nuclear power for electricity generation, with the first nuclear power plant going online in 1957 in Shippingport, Pennsylvania.

Similar to other thermal powerplants like coal, oil and gas, nuclear reaction creates heat which is used to turn water into steam. This turns the turbines attached to the generators which produce electricity.

I don't believe that the design is fixed at this time. General Atomics and others have been working on designs and one has been built in South Africa, but the companies are still working out the final design. A link is provided to an interesting read on the latest evelopments.

The advanced gas-cooled reactors, at least the ones I know, have been built in the UK but not elsewhere. The last ones built were at Heysham Stage 2 and Torness, in Scotland. As far as I can remember the number of channels was 332. I think the first answer may have been on the pebble bed reactor, which is gas cooled and advanced, but not the same as the AGR in UK.

If you are talking about the material inside which the nuclear fuel is sealed, zircaloy is about the most common. This alloy, which is available in several "flavors" including Zirc-1, Zirc-2 and Zirc-4 are each almost all zirconium (over 95%). Nuclear fuel in the form of pellets or plates is welded inside zircaloy cladding to contain all the fission fragments that will appear as the fuel is burned. This material doesn't absorb thermal neutrons very well, so it won't "dilute" the chain reaction by taking some of these neutrons out of circulation. As one might expect, the heat generated within the fuel elements is transferred out through the zircaloy and into the primary coolant of the reactor. Wikipedia has some more information on zircaloy, and a link is provided.

Nuclear fission is currently used to generate electrical energy in nuclear power plants. This process involves the splitting of uranium or plutonium atoms, which releases a large amount of energy that is used to heat water and produce steam to drive turbines and generate electricity.

• It was first used in Obninsk in former Soviet Union.
• The world's first nuclear power plant was commissioned on June 27, 1954 in Obninsk.
• The Obninsk nuclear power plant featured one 5 mWt AM-1 (Atom Mirny or Peaceful Atom) reactor to generate electricity and facilitate experimental nuclear research.

In a nuclear power plant, the nuclear reactors are (generally) fission reactors that split atoms (of nuclear fuel) through a continuous, controlled neutron chain reaction. The primary useful product of a nuclear reactor is heat. The heat is used to generate steam that will drive steam turbines to generate electric power. Reactors are also used to produce nuclear material that is then applied to medicine or to make sources for radiography (x-ray pictures of welds and stuff) and other applications. There are other applications, like the generation of plutonium which is used for weapons or fuel for other reactors. Most reactors are designed, constructed and used to generate electric power. These reactors are set up to deliver large quantities of heat that is used to produce steam. This steam is used to drive steam-driven turbines, which generate electricity. There is a ton of information about the types of reactors and the applications to which they are put available from our friends at Wikipedia. A link is provided.

The countries known to have nuclear weapons are:

United States

Russia

United Kingdom

France

China

India

Pakistan

North Korea

Israel

Germany, Italy, Japan and South Africa have the capability of building nuclear weapons but have not done so.

Canada once had nuclear weapons, but has dismantled its weapons and permanetly deacitvated its nuclear weapons program. So far it is the only country to do so.

Nuclear reactors can not explode like a nuclear bomb. A lot of bad things can happen, but that is not one of them.

Nonnuclear Explosion:

First, it is useful to distinguish "normal" explosion from nuclear bomb. (We'll get to the bomb part shortly.)

Explosions of many kinds can occur and they can occur at nuclear power plants and reactors just as anywhere else. It is not odd to have a steam powered explosion at a power plant whether it is nuclear or coal or gas because all of these types of power plants are converting heat into mechnical energy through a trubine or similar machine and the turbine generates electricity. The heat creates steam at high pressure and a mechanical failure can result in an explosion.

An explosion of the sort caused by excess heat or mechanical failure counts as one resulting from mismanagement.

Explosions can be caused by humans too. A human can place a regular bomb at a nuclear power plant or a human can fire a missile at a power plant and then the power plant, nuclear or not, explodes.

Nuclear Bomb Explosions:

The principle behind a nuclear bomb is the idea of the chain reaction. Nuclear fission is the process of a large nucleus, like uranium, breaking apart into smaller pieces and releasing energy in the process. When one nucleus decays, it causes other nuclei to decay and they in turn cause more. Such is a chain reaction, it feeds itself and the process grows and results in an explosion as long as there is enough fuel. That last part is the key because you can't make a nuclear bomb explode (or any bomb) if you run out of fuel.

Now, we get to the part about "weapons grade" nuclear material. A nuclear weapon requires a high concentration of fissionable material of the proper type and enough of it and a way to keep it in place long enough for the chain reaction to produce enough energy to be a bomb.

Nuclear reactors are not built with weapons grade material. That is essential. Further, the elaborate process of containment to hold the bomb material in place requires special engineering and that is not in a nuclear reactor. The quantity of material required for a bomb is very very large unless it is highly purified and it is not so purified in nuclear reactors.

No mismanaged nuclear plant, no nuclear plant accident of any kind, can cause a massive nuclear explosion like the blast of a nuclear weapon.

Nuclear Powered (non-bomb) Explosions:

Though a reactor can't explode like a nuclear bomb, the explosions that can occur are extremely dangerous and can spew radioactive materials widely, they are just not nuclear bomb explosions. Usually the explosions allow the radioactive core of reacting material to overheat and the radioactive material from several separate areas may combine and further heat, enhancing the ongoing nuclear chain reactions. It is not possible to go through explanations of the various scenarios, but under the worst conditions, the heated material explodes like a regular bomb and spreads itself over a large area destroying everything nearby. It is not nearly as large as a true nuclear bomb which can level a city. What is does do is spead a lot of radioactive material around. The process does not even have to explode to do that, it can just heat up enough to vaporize radioactive materials that are then released.

All of the examples of nuclear reactor disasters fall into the category on non-bomb disasters. All were and will be the type that creates and disperses harmful radioactive material and that is the core of the problem.

Final Note:

Though no sane design of a nuclear reactor could explode like a nuclear bomb, the process of making the materials the reactor uses is a process that could potentially make weapons grade material. Further, the used fuel can serve as a starting material for bomb making. In that case, it is not the reactor but the treatment of material before or after that can be directed towards a weapon.

The subject gets very complicated and this little description could not provide a person with enough information to say they understand it. More reading is recommended.