0
The best moderators are those with atomic masses close to the mass of the neutron itself, maximizing the energy transferred from the neutron to the atom in every collision. Deuterium is the best moderator, with heavy water a close second. Oxygen trails well below that in third, with carbon a close fourth. Beryllium is fifth, but is far too expensive to use. Ordinary water is sixth, followed very closely by ordinary hydrogen. Other elements are practically ineffective as moderators as the mass difference is far too large and neutrons either bounce off their nuclei without slowing or get absorbed (boron has a small enough mass to slow neutrons but absorbs neutrons too easily, it is used in control rods not as a moderator).
Many compounds of the above listed elements are also good moderators and typically better than simple mixtures of identical ratios of those elements (for complex physical reasons). For example organic compounds (e.g. hydrocarbons) work good due to the carbon hydrogen present. In fact the body's of living things (e.g. plants, animals, fungi) act as good enough moderators that they have contributed to some criticality event accidents in nuclear research and the nuclear industry.
What else can I help you with?
What are the uses of carbon heavy water and concrete in the nuclear reactor?
Carbon in the form of graphite is used in some types of reactors as the moderator*.Heavy water is used in some types of reactors as the moderator*.Light water is used in some types of reactors as the moderator*.Light water is used in most current types of reactors as coolant and in the form of steam to drive the turbines.Liquid metals (Sodium, NaK, Mercury, etc.) are used in some types of reactors as coolant.Concrete, often borated concrete to absorb neutrons better, is used in reactors as radiation shielding.*Moderator: a material that slows highly energetic fission neutrons rapidly to thermal energies to prevent their capture by Uranium-238 and increase their chance of causing more fissions of Uranium-235 to keep the reactor running.
Annually how much carbon dioxide does nuclear power produce?
Total greenhouse gas emissions (most of it comes from carbon dioxide) from nuclear power is about 5.7 gCeq/kwh (grams of carbon equivalent per kWh of electricity produced). To calculate annual emission form nuclear power, you have to apply it to the electricity generation capacity of a nuclear power plant.
What type of substance is graphite?
Graphite is a crystalline form of the element carbon. It is a non-metal and a good conductor of electricity due to its unique structure of bonded carbon atoms. It is commonly used in pencils, lubricants, and as a component in nuclear reactors.
Is nuclear power a natural resource?
Nuclear power itself is not a natural resource; rather, it is a method of generating energy using nuclear reactions. The primary natural resource used in nuclear power is uranium, which is mined from the earth. Other materials, such as thorium, can also be utilized in nuclear reactors. While nuclear power is a low-carbon energy source, it relies on these natural resources for fuel.
Different kinds of powerplant?
The main types of nuclear power plant in use in the world, and exclusively in the US are PWR (Pressurised Water Reactor) and BWR (Boiling Water Reactor) types. These use normal water as moderator and enriched uranium fuel. In Canada a heavy water moderated type of reactor has been successfully used and exported to several countries. In the UK gas cooled reactors have mainly been used, firstly the magnox type and latterly the AGR. Both use carbon dioxide cooling and graphite moderator. In Russia the RBMK type was developed which combined graphite moderating with water cooling. This type has been largely discontinued after Chernobyl. High temperature helium cooled reactors and fast reactors liquid metal cooled have been tried as prototypes but not commercially.
Is helium or carbon or hydrogen or beryllium the best ideal moderator for use in the core of a nuclear reactor?
Carbon is a very good moderator, for use in gascooled reactors, the others not.
What are graphite's uses?
Graphite is a pure form of coal or carbon. It is a good conductor of heat and electrcity. It is used as a neutron moderator in nuclear reactors of type Gas Cooled reactors.
What are the uses of carbon heavy water and concrete in the nuclear reactor?
Carbon in the form of graphite is used in some types of reactors as the moderator*.Heavy water is used in some types of reactors as the moderator*.Light water is used in some types of reactors as the moderator*.Light water is used in most current types of reactors as coolant and in the form of steam to drive the turbines.Liquid metals (Sodium, NaK, Mercury, etc.) are used in some types of reactors as coolant.Concrete, often borated concrete to absorb neutrons better, is used in reactors as radiation shielding.*Moderator: a material that slows highly energetic fission neutrons rapidly to thermal energies to prevent their capture by Uranium-238 and increase their chance of causing more fissions of Uranium-235 to keep the reactor running.
What types of nuclear reactors are used in the UK?
Mostly at present they are AGR's that is Advanced Gascooled Reactors, using carbon dioxide coolant, graphite moderator, and slightly enriched fuel clad in stainless steel sheaths. There is one PWR running and all new ones built will be PWR.
What is a nuclear reaction coolant?
Presumably you mean nuclear reactor coolant? This is the fluid that transfers the reactor thermal output to the steam raising units in a PWR, or to the turbine in a BWR, in which cases it is natural water. Gas cooled reactors can use carbon dioxide or helium, and CANDU reactors use heavy water.
What other element can thorium be combined with to create a new product?
Thorium can be combined with uranium to create nuclear fuel used in certain types of nuclear reactors, such as thorium-based reactors. This combination can enhance the sustainability and safety of nuclear power generation.
Annually how much carbon dioxide does nuclear power produce?
Total greenhouse gas emissions (most of it comes from carbon dioxide) from nuclear power is about 5.7 gCeq/kwh (grams of carbon equivalent per kWh of electricity produced). To calculate annual emission form nuclear power, you have to apply it to the electricity generation capacity of a nuclear power plant.
Are nuclear reactors a cause of global warming?
No, they emit no carbon dioxide emissions (except during construction). France, for example, has decreased their CO2 emissions by 95% using nuclear. It is one of the true green energies around.
How much of nuclear power do you use in the US?
In the US, nuclear power provides about 20% of the total electricity generation, making it the largest source of low-carbon electricity. There are 93 commercial nuclear reactors operating in 28 states.
Is uranium good for climate change?
Uranium is used as nuclear fuel for nuclear power reactors. Nuclear power plants don't contribute to global warming, greenhouse effect, carbon dioxide releasing. Uranium is now the most important alternative to fossil fuels.
Oxide of which element used as coolant?
Helium is commonly used as a coolant in nuclear reactors because of its low boiling point, high thermal conductivity, and inert properties.
What type of substance is graphite?
Graphite is a crystalline form of the element carbon. It is a non-metal and a good conductor of electricity due to its unique structure of bonded carbon atoms. It is commonly used in pencils, lubricants, and as a component in nuclear reactors.
