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Nuclear Reactors
Nuclear reactors are devices that maintain nuclear reactions. They are used in creating power and elements.
890 Questions
Which metals are used in nuclear reactors except thorium?
for example:
- uranium as nuclear fuel
- zirconium for nuclear fuel cladding
- stainless steel for different structures
- cadmium for neutron capture
How many joules does a high grade nuclear reactor give off?
Commercial nuclear reactors operating in the US and around the world come in many different sizes
and generation capacities. As an example, I found the "Quad Cities" power plant in western Illinois,
a couple hundred miles from my home.
The Quad Cities power plant is named for the nearby cities of Davenport, Rock Island, Moline, and
East Moline. It serves all four cities in addition to the western part of Exelon's service area in Illinois.
Quad Cities operates two boiling water reactors, each with a rated maximum capacity of 867 megawatts of
electricity. That's 867 million joules of energy per second out of each one, when it's running wide open
at max capacity.
It's a bit sloppy to speak of energy being "given off" by a nuclear reactor. Any energy "given off" by a
commercial power plant is energy that they can't ship out and sell. And in the case of a nuclear plant,
there are probably a lot of folks living in the neighborhood who would become a mite irritated if any of
that nuclear energy were to come drifting out between the cracks.
The energy generated by the nuclear reactions is kept tightly sealed inside the reactor, and the reactor
is enclosed inside many feet of concrete. The intense heat in the reactor is carried away by another sealed
system of water. The water boils, and runs steam turbine generators, just as if it had been boiled by a coal
or oil fire, instead of by nuclear fission converting mass to energy.
Why lithium use as heat transfer agent in nuclear reactors?
Its not used in any reactor designs. Most use ordinary water. A few designs use molten metals like sodium, NaK (sodium-potassium alloy), mercury, etc. because they do not slow the neutrons as water would and they want fast neutrons in these designs. These metals also transfer heat more efficiently than water does.
Does nuclear energy take place at high temperatures?
Your question expresses a significant bit of conceptual confusion. Perhaps I can clear up some of this confusion and at the same time answer your question.
What we call temperature is simply the manifestation of kinetic energy at the level of the atom (i.e. slow moving atoms = low temperature, fast moving atoms = high temperature). What we call nuclear energy is simply an excess in the nuclear binding energy, which is the energy binding the protons and neutrons together inside the nucleus and is a manifestation of the strong nuclear force and to a lesser extent the weak nuclear force. This movement of atoms has no affect at all on whether there is or is not excess nuclear energy inside atomic nuclei or if that excess nuclear energy is being released or even can be released. Those nuclei having the least nuclear binding energy are the nuclei of the elements from iron through lead, both the elements lighter than iron and the elements heavier than lead have more nuclear binding energy (which can be considered to be excess nuclear binding energy that could potentially be released).
There are three processes that can release excess nuclear energy: radioactive decay, nuclear fission, and nuclear fusion. All of these processes transform nuclear energy to kinetic energy at the level of the atom (i.e. temperature aka heat), and thereby convert a small amount of the mass of the atom into energy. Of these three both radioactive decay and nuclear fission can take place at any temperature, even those so cold as to approach absolute zero. Neither radioactive decay nor nuclear fission takes place any faster or slower with a change in temperature. Nuclear fusion though can only take place at very high temperatures (and pressures) as the nuclei must be very close together and moving fast enough to be able to collide and fuse, despite the strong electrostatic repulsion due to both nuclei involved being positively charged. But this is a threshold temperature, even at high temperatures just below the threshold no nuclear fusion can take place at all and once above the threshold and nuclear fusion begins, raising the temperature further has very little affect on the rate at which that nuclear fusion takes place.
Nuclear reactors operate using the process of nuclear fission and generate heat by both nuclear fission and radioactive decay. We are not yet able to extract nuclear energy in a controlled manner using the process of nuclear fusion (only explosive release of nuclear energy has ever been successfully done using the process of nuclear fusion).
Are control rods of nuclear reactors used to stop a leak?
No, control rods in nuclear reactors are not used to stop leaks. Control rods are used to regulate the power output of the reactor by absorbing neutrons and controlling the rate of nuclear fission. To stop a leak in a nuclear reactor, different containment and safety systems are employed to isolate and contain the leak.
- sun, fusion of hydrogen nuclei making helium nuclei (not radioactive)
- nuclear reactor, fission of uranium nuclei making a wide variety of different fission product isotopes having mass numbers from 72 to 161 (all very radioactive)
What type of energy is a nuclear power plant?
Nuclear power plants generate electrical energy through nuclear fission, which is the splitting of atoms to produce heat that is used to create steam and drive turbines. This process converts nuclear energy into electrical energy.
Are control rods in nuclear reactors made of graphite?
No, control rods in nuclear reactors are not made of graphite. The control rods have to be able to gather up the neutrons to shut the reactor down, so boron is often selected. Graphite is used in some reactors as a moderator, and a moderator slows down neutrons. The slower neutrons have a greater ability to undergo neutron capture to continue the chain.
How do you control nuclear reactors inside a nuclear reactor?
Nuclear reactors are controlled using control rods that absorb neutrons and regulate the rate of fission in the reactor core. By adjusting the position of these control rods, operators can manage the nuclear reaction and control the power output of the reactor. Additionally, coolant flow and reactor temperature are also monitored and adjusted to ensure safe and stable operation.
What are the 3 main sections of a nuclear power plant?
The three main sections of a nuclear power plant are the reactor, where nuclear reactions occur to produce heat; the turbine, which converts the heat energy into mechanical energy; and the generator, which converts the mechanical energy into electricity.
What does a moderator do in nuclear power plants?
The moderator slows (moderates their speed/energy) neutrons from the 1 MeV that they have when emitted in fission to less than 1 eV.
The reason a moderator is needed in most reactors is that their fuel is still mostly Uranium-238, which easily captures 1 MeV neutrons and potentially stopping the neutron chain reaction but is unable to capture neutrons less than 1 eV which still easily fission the small percentage of Uranium-235 in the fuel.
Hydrogenic materials are used as moderators in nuclear reactors to slow down the neutrons Why?
Hydrogenic materials, like water or heavy water, are used as moderators in nuclear reactors because they are effective at slowing down neutrons through elastic scattering. Slowing down neutrons is important to make them more likely to interact with other nuclei, initiating a chain reaction in the reactor. Hydrogen atoms in these materials have a similar mass to neutrons, making them efficient at transferring kinetic energy and slowing down the neutrons.
What is the major disadvantage of using nuclear fusion reactors?
We don't have nuclear fusion reactors. We have not been able to sustain a controlled fusion reaction for more than a brief moment in time, and of more than a small amount of power.
Only the Sun and stars have controlled fusion reactions, and Hydrogen bombs have uncontrolled fusion reactions.
The problem is in maintaining the extremely high temperature and pressure required to sustain a fusion reaction, while at the same time containing the plasma that results from it. It is so hot that no container will hold it. We can build magnetic "bottles" so to speak, but the enormous flux required to do that requires super magnets, and that requires super-conductors and super-cold temperatures. Placing a super-hot plasma flow within the boundaries of a super-cold magnet is just not something we have accomplished yet.
We are working on it, but, barring any stupendous discovery, I think controlled fusion reactors are at least 50 or a 100 years away.
What is the source of energy in nuclear power plants?
The source of energy in almost all nuclear power plants is fission or the splitting of the atom. There are a few experimental fusion power plants, (or the joining of the atoms), but, there are few of them, since the energy needed to produce fusion is extremly high, and only last a few seconds.
Around 99.99% of nuclear power plants are fission power plants.
What is true about nuclear power?
Nuclear power is a low-carbon energy source that can generate significant amounts of electricity. It produces a large amount of energy from a small amount of fuel, but also comes with challenges such as radioactive waste disposal and the potential for accidents. Overall, it is a controversial energy source with both benefits and risks.
How many watts electricity is produced by a nuclear reactor?
The electricity produced by a nuclear reactor can vary depending on its size and design, but a typical nuclear reactor can generate anywhere from 500 megawatts to 1,500 megawatts of electricity.
Why is uranium 238 not used in nuclear reactors?
The ionization-type smoke detectors use a tiny Americium source to generate alpha particles. Cobalt-60 does not generate alpha particles. Alpha radiation is actually a helium-4 nucleus - two protons and two neutrons. It has very limited penetrating power because it is a big, heavy particle and it tends to collide (scatter) when it tries to go through anything, even just air. The detector makes use of the fact that alpha particles ionize the heck out of air, and are scattered by anything in the air. The cobalt-60 decays by beta and gamma emission, and that kind of radiation has "too much" penetrating power to make the detector usable the way it is set up.
How is radioisotopes used in nuclear reactors?
Radioisotopes are used in nuclear reactors as fuel to generate heat through nuclear fission. The heat produced is used to generate steam, which drives turbines to generate electricity. Radioisotopes such as uranium-235 and plutonium-239 are commonly used in nuclear reactors.
What is the payback time of nuclear power stations?
The payback time for nuclear power stations varies depending on factors such as construction costs, operating expenses, and maintenance costs. Generally, it can range from 10 to 20 years. However, nuclear power stations have a long operational lifespan, so they can generate electricity for many years once the initial investment is recouped.
Why is a coolant important in a nuclear reactor?
Coolant is important in a nuclear reactor to transfer heat away from the reactor core, preventing it from overheating. It helps regulate the temperature within safe limits by absorbing and removing the heat generated during the nuclear fission process. Additionally, coolant also serves to slow down neutrons to facilitate efficient fission reactions.
Where is nuclear fuel generated?
Nuclear fuel is generated in nuclear reactors, where a process called nuclear fission converts uranium isotopes into energy. This energy is harnessed to generate electricity in power plants. The fuel is typically produced in specialized facilities where uranium is enriched and fabricated into fuel rods before being loaded into reactors.
The nuclear reactions in the Sun primarily involve fusion of hydrogen nuclei to form helium, releasing energy in the process. In a nuclear reactor, the reactions typically involve fission of heavy nuclei like uranium or plutonium, releasing energy through splitting these nuclei. The conditions and mechanisms governing the reactions in the Sun and in a nuclear reactor are different due to the vastly varying scales and environments of the two systems.
What kinds of people use plutonium?
Plutonium is primarily used by nations for nuclear weapons and nuclear reactors. It is a highly regulated material due to its potential for use in weapons. Scientists also use plutonium for research and testing purposes.
What are control rods in a reactor core used for?
Control the reaction rate by absorbing neutrons that are generated but not needed. They are typically made of cadmium or boron, elements that have very large neutron capture crosssections (a measurement of the statistical probability of a given nuclear interaction).
What is the process of refining uranium to the form used in the reactor?
Its called enrichment and it can be done many different ways. Most ways of enriching uranium require the use of what is probably the most corrosive, toxic, and violently reactive with water chemicals there is: uranium hexafluoride UF6. uranium hexafluoride will corrode almost all metals except pure nickle. uranium hexafluoride attacks all organic compounds. uranium hexafluoride on contact with water ignites and can explode.
Enrichment methods using uranium hexafluoride include:
- gaseous diffusion
- thermal diffusion
- centrifuge
- LASER separation
- electromagnetic separation, aka calutron, aka mass spectrometer
- plasma separation
