0
Neutron absorption, or neutron capture, converts fertile materials, which cannot be used directly for fuel in a nuclear reactor, into fissile or fissionable fuels, which can.
Current nuclear reactors use fission to provide heat. Fission requires one of three kinds of fuel, fissile, fissionable, or fertile. Fissile fuel undergoes fission spontaneously and provides sufficient neutrons in the process to produce a chain reaction, if there is a enough such fuel around, or a critical mass. Fissionable fuel will undergo fission if it is hit hard by a neutron with the proper energy. Fertile material can be converted into fissile or fissionable fuel through neutron capture.
Neutron capture happens when a neutron collides with the nucleus of an atom. becoming part of it. This changes the isotope of the atom, increasing the number by one. Thus n + 232Th -> 233Th. The half life of 232Th is 14 billion years, but he half life of 233Th is a little less than 22 minutes. So the 233Th quickly decays, producing 233Pa. 233Pa has a half life of a little less than 27 days, so it also quickly decays, and it produces 233U. 233U is fissile, so it undergoes fission spontaneously and is a useful fuel for the nuclear reactor. Thus, the neutron capture has converted material that cannot be used directly for fission into something that can.
In a conventional reactor, the neutrons needed are produced by the decay of fissile fuel. There are other kinds of reactors, however, such as an accelerator driven system, in which the neutrons are produced from outside the reactor. This means that a critical mass is not really necessary to produce the reaction. The accelerator driven system, also called an energy amplifier or subcritical reactor, is now in the development stage.
Please bear in mind that this description of things is quite simplistic. Things usually happen this way in a neutron flux, but there are a lot of other outcomes. An atom of 233U is likely to capture another neutron and become 234U, for example. Also, collisions with neutrons cause atoms to decay or divide, and so the half lives do not represent what is actually going on in the reactor; an atom with a 27 day half life is very unlikely to last that long in a neutron flux.
What else can I help you with?
How can nuclear fission be slowed?
Nuclear fission can be slowed by inserting control rods, such as boron or cadmium, into the reactor core. These control rods absorb neutrons, reducing the number available to initiate fission reactions and thus slowing down the rate of fission in the reactor.
In nuclear reactor how will you say control rods absorbs only one neutron?
Control rods are made of materials that readily absorb neutrons, such as boron or cadmium. These materials have a high neutron absorption cross section, which means they are very likely to absorb a neutron when it comes in contact with them. The design and placement of control rods in a nuclear reactor are carefully engineered to ensure that they absorb just enough neutrons to control the rate of the nuclear reaction without completely stopping it.
What is fission cross section in nuclear reactor?
The fission cross section in a nuclear reactor is a measure of the probability that a neutron will induce fission in a particular nucleus. It is a crucial parameter for determining the neutron flux and reaction rates within the reactor core. Different isotopes have different fission cross sections depending on their ability to undergo fission when struck by a neutron.
Does neutron absorption speed up the nuclear reactor?
It is the moderator in a nuclear reactor that is used to slow neutrons down in a thermonuclear reactor. The moderator, which is often water, slows the neutrons by providing a "target" for the neutron to slam into. The resulting collision (called a scattering event) will allow the moderator to absorb some of the kinetic energy from the neutron, and that neutron will come away at a lower velocity than it did coming in. The hydrogen in water (it's H2O) has, in most cases, a single proton in its nucleus. As the proton in a hydrogen nucleus has approximately the same mass as a neutron, there will be, in general, a larger amount of energy stripped from the neutron in a given scattering event. (If you consider, say, a scattering even between a golf ball and a bowling ball, the golf ball won't lose much energy to the bowling ball. But if the golf ball undergoes scattering with another golf ball, there is a "better" result and more slowing of the neutron.) In addition to the use of water (both light and heavy water) as a moderator, we also find that graphite (an allotrope of carbon -- pencil lead) and liquid metals are also used as moderators. The same idea applies, and the moderator, whatever one it is, provides a target for higher energy neutrons to slam into. The result of the scattering events is that the neutrons are slowed in the process.
What is the function of light water in nuclear reactor?
Light water is used:as nuclear fuel reactor coolantto produce steam that turns the turbines and hence turning the electric generation systemas a neutron moderatoras coolant in safety systems
What does nuetron absorption accomplish in a nuclear reactor?
Neutron absorption is the key to the operation of a nuclear reactor as this is what perpetuates the chain reaction. Neutrons can be absorbed by a number of things within the core of an operating reactor, but when a fuel atom absorbs a neutron, it becomes unstable and fissions. The fission event releases fission fragments, energy, and more neutrons, which will, when absorbed, continue the chain reaction.
What does neutron absorbtion accomplish in a nuclear reactor?
Neutron absorption in a nuclear reactor can help control the rate of fission reactions by absorbing excess neutrons to prevent them from causing further reactions. This process helps regulate the reactor's power output and overall stability. Additionally, some materials used for neutron absorption, like control rods, can also be used to shut down the reactor in emergency situations.
What is the purpose of the reactor chamber in a nuclear reactor?
neutron absorber
What is neutron absorption?
Neutron absorption is the process wherein an atomic nucleus will absorb a neutron. Many different atomic nuclei will do this, and different nuclei will present a larger of smaller target for the neutron, as you might have guessed. This is the neutron absorption cross section for the material, and it varies as the material does and as the kinetic energy of the neutron does, as well. You may have figured out that there are many different resulting products or outcomes that can be seen from neutron absorption. It is neutron absorption that powers up a chain reaction, so let's look at that aspect of this phenomenon. In a nuclear reactor, some spontaneous fissions will release neutrons, and these neutrons will, if the control rods are pulled out sufficiently, begin a chain reaction. The nuclear fuel, usually either uranium or plutonium, will absorb a neutron (after some slowing down of that neutron), and they'll fission as a result. These fissions will release more neutrons, which will be absorbed and will create more fissions, which will release more neutrons, etc. A neutron released from a fission event will have a high kinetic energy; it will be moving very quickly. It might be absorbed, but will have a higher probability of being absorbed if it is slowed down, or thermalized. The moderator in a reactor, usually water, does this slowing down of the neutrons. The slower neutrons have a much higher probability of being absorbed and continuing the chain. Fission by neutron absorption is the mechanism by which a nuclear chain reaction is maintained in a nuclear reactor.
Why normal water is not used as moderator in nuclear reactor?
Normal water, or light water, absorbs too many neutrons to be an effective moderator in a nuclear reactor. This absorption can make it difficult to sustain a nuclear chain reaction. Instead, reactors often use heavy water or graphite as a moderator, which have lower neutron absorption rates.
How does the use of a neutron reflector enhance the efficiency of a nuclear reactor?
A neutron reflector enhances the efficiency of a nuclear reactor by reflecting neutrons back into the reactor core, increasing the likelihood of nuclear reactions and the production of energy. This helps sustain the chain reaction and improve the overall performance of the reactor.
How can nuclear fission be slowed?
Nuclear fission can be slowed by inserting control rods, such as boron or cadmium, into the reactor core. These control rods absorb neutrons, reducing the number available to initiate fission reactions and thus slowing down the rate of fission in the reactor.
What accomplishes the release of the nuclear energy in a reactor?
neutron chain reaction
In nuclear reactor how will you say control rods absorbs only one neutron?
Control rods are made of materials that readily absorb neutrons, such as boron or cadmium. These materials have a high neutron absorption cross section, which means they are very likely to absorb a neutron when it comes in contact with them. The design and placement of control rods in a nuclear reactor are carefully engineered to ensure that they absorb just enough neutrons to control the rate of the nuclear reaction without completely stopping it.
Which component within a nuclear reactor directs neutron bombardment?
The control rods within a nuclear reactor help direct neutron bombardment. By adjusting the position of the control rods, operators can regulate the rate of nuclear fission reactions and control the release of energy.
What does the neutronic reactor do?
A neutronic reactor is a type of nuclear reactor that uses a high-energy neutron chain reaction to generate power through the fission of atomic nuclei. This type of reactor is designed to maximize neutron interactions for efficient energy production.
In a nuclear reactor lowering control rods will result?
In a nuclear reactor, lowering control rods will result in the absorption of more neutrons, which slows down the nuclear chain reaction. This leads to a decrease in the reactor's power output or can even shut down the reactor completely.
