Uranium carbide
Encyclopedia
Uranium carbide, a carbide
Carbide
In chemistry, a carbide is a compound composed of carbon and a less electronegative element. Carbides can be generally classified by chemical bonding type as follows: salt-like, covalent compounds, interstitial compounds, and "intermediate" transition metal carbides...

 of uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

, is a hard refractory
Refraction (metallurgy)
In metallurgy, refraction is a property of metals that indicates their ability to withstand heat. Metals with a high degree of refraction are referred to as refractory. These metals derive their high melting points from their strong intermolecular forces...

 ceramic
Ceramic
A ceramic is an inorganic, nonmetallic solid prepared by the action of heat and subsequent cooling. Ceramic materials may have a crystalline or partly crystalline structure, or may be amorphous...

 material. It comes in several stoichiometries (x), such as uranium monocarbide (UC, CAS number 12070-09-6), uranium sesquicarbide (U2C3, CAS number 12076-62-9),
and uranium dicarbide (UC2, CAS number 12071-33-9).

Like uranium dioxide
Uranium dioxide
Uranium dioxide or uranium oxide , also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used...

 and some other uranium compounds, uranium carbide can be used as a nuclear fuel
Nuclear fuel
Nuclear fuel is a material that can be 'consumed' by fission or fusion to derive nuclear energy. Nuclear fuels are the most dense sources of energy available...

 for nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...

s, usually in the form of pellets or tablets. Uranium carbide fuel was used in late designs of nuclear thermal rocket
Nuclear thermal rocket
In a nuclear thermal rocket a working fluid, usually liquid hydrogen, is heated to a high temperature in a nuclear reactor, and then expands through a rocket nozzle to create thrust. In this kind of thermal rocket, the nuclear reactor's energy replaces the chemical energy of the propellant's...

s.

Uranium carbide pellets are used as fuel kernels for the US version of pebble bed reactor
Pebble bed reactor
The pebble bed reactor is a graphite-moderated, gas-cooled, nuclear reactor. It is a type of very high temperature reactor , one of the six classes of nuclear reactors in the Generation IV initiative...

s; the German version uses uranium dioxide
Uranium dioxide
Uranium dioxide or uranium oxide , also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used...

 instead.

As nuclear fuel, uranium carbide can be used either on its own, or mixed with plutonium carbide
Plutonium carbide
Plutonium carbide comes in several stoichiometries .It can be used as a nuclear fuel for nuclear reactors in conjunction with uranium carbide. The mixture is also labeled as uranium-plutonium carbide ....

 (PuC and Pu2C3). The mixture is also labeled as uranium-plutonium carbide (PuC U).

Uranium carbide is also a popular target material for particle accelerator
Particle accelerator
A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...

s.

Ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

synthesis from nitrogen and hydrogen is sometimes accomplished in the presence of uranium carbide acting as a catalyst.
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