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In a nuclear reactor the moderator is usually made of graphite placed between the fuel rods used to slow down neutrons all of the above none of the above?
The moderator in a nuclear reactor is usually made of graphite, which is used to slow down neutrons. So, the correct answer is "all of the above".
Are control rods made of graphite in a nuclear reactor?
Control rods in a nuclear reactor are typically made of materials like boron or cadmium that can absorb neutrons to regulate the nuclear reaction. Graphite is used as a moderator to slow down neutrons in certain types of reactors, but it is not typically used in control rods.
What was the function of graphite in the first atomic reaction?
Graphite was used as a moderator in the first atomic reaction to slow down neutrons released during the fission process. Slowing down the neutrons increases the likelihood of them causing further fission reactions, enabling a self-sustaining chain reaction.
Why is graphite used as a moderator in some nuclear reactors?
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.
Does the cadmium in the control rod slow down a nuclear reaction by absorbing neutrons?
Yes, cadmium in control rods is used to slow down or stop a nuclear reaction by absorbing neutrons. When control rods are inserted into a nuclear reactor core, cadmium atoms capture neutrons, preventing them from causing further fission reactions and helping regulate the reactor's power output.
In a nuclear reactor the moderator is usually made of graphite placed between the fuel rods used to slow down neutrons all of the above none of the above?
The moderator in a nuclear reactor is usually made of graphite, which is used to slow down neutrons. So, the correct answer is "all of the above".
What is the function of graphite in a nuclear reactor?
Graphite is used as a moderator in nuclear reactors to slow down neutrons produced during nuclear fission. Slower neutrons are more likely to cause additional fission reactions, allowing for a sustained nuclear reaction. Graphite is also used as a structural material in some reactor designs.
What is the function of graphite in the first atomic reactor?
The graphite acts as a moderator, to slow neutrons down. Most fission reactors work on the basis of slow or thermalised neutrons, though some have been built using fast neutrons. When the neutrons are ejected from the uranium nucleus as it fissions or splits, they come off at high speed, but in order to be captured by another nucleus of U-235 they need to be slowed down. This is simply a physical fact, U-235 captures slow neutrons much more readily than it does fast neutrons. Graphite was used in the first demonstration reactor in 1942 and in subsequent bigger reactors at Hanford Wa. It had to be made specially with very high purity to avoid absorbing too many neutrons. Other moderators used are heavy water, as in CANDU reactors, and light water as in PWR. Light water absorbs more neutrons so the fuel has to be enriched in U-235.
Slows down neutrons in a nuclear reactor?
In a nuclear reactor, materials such as water or graphite are commonly used as neutron moderators to slow down fast-moving neutrons to speeds where they are more likely to induce fission in uranium or plutonium atoms. Slowed down neutrons are termed thermal neutrons and are key to sustaining a nuclear chain reaction.
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.
Are control rods made of graphite in a nuclear reactor?
Control rods in a nuclear reactor are typically made of materials like boron or cadmium that can absorb neutrons to regulate the nuclear reaction. Graphite is used as a moderator to slow down neutrons in certain types of reactors, but it is not typically used in control rods.
Why is graphite used in nuclear reactors?
Graphite is used in nuclear reactors because it has the ability to slow down neutrons, which helps control the nuclear fission process and maintain a stable reaction. This helps regulate the release of energy and prevent the reactor from overheating.
Why is graphite used in nuclear reactors?
Graphite can be used as a moderator, that is to slow down the fast neutrons produced in fission. Early reactors including Hanford and Windscale used graphite, and in the UK this type of reactor was built extensively for power production. However water reactors such as PWR and BWR have proved cheaper to build and have a longer life, so graphite is now little used, there are a few still running but none being planned or built as far as I know.
Why neutrons are made slow in a reactor?
Neutrons are slowed down in a reactor to increase the likelihood of them causing fission reactions in nuclear fuel. Slower neutrons are more easily absorbed by the fuel, increasing the overall efficiency of the reactor. This process is achieved through a moderator, such as water or graphite, which helps reduce the speed of the neutrons.
Why are graphite rods used in a nuclear pile?
Graphite is a "moderator" that slows down the fast neutrons which are produced during the fission process. Fast neutrons are captured by uranium-238 atoms removing them from the chain reaction process. Slow "thermal" neutrons avoid uranium-238 atoms and easily split uranium-235 atoms, producing 2 to 3 more neutrons that can continue the chain reaction. For a moderator to be effective it must slow neutrons rapidly (before too many can be captured by uranium-238 atoms and thus removed from the chain reaction). The most effective moderators in decreasing order are: heavy water (D2O), graphite (C), light water (H2O).
What was the function of graphite in the first atomic reaction?
Graphite was used as a moderator in the first atomic reaction to slow down neutrons released during the fission process. Slowing down the neutrons increases the likelihood of them causing further fission reactions, enabling a self-sustaining chain reaction.
Are there fast neutrons?
Yes, in fact for a sustainable nuclear chain reaction to work, you have to slow neutrons down.
