Nitride uranium

In this design, the UN fuel will be located in the drum of the core, clad in a layer of rhenium and niobium 1% zirconium. This rhenium layer is required because of incompatibilities between nitrogen and niobium 1% zirconium. The nitrogen out-gassing 

This table shows that helium has the highest thermal conductivity with the helium/xenon mixture coming in second. 

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Nitrides. Uranium nitrides are weU known and are used in the nuclear fuel cycle. There are three nitrides of exact stoichiometry, uranium nitride [2565843-9], UN U2N3 [12033-85-1/ and U4N2 [12266-20-5]. In addition to these, nonstoichiometric complexes, U2N3, where the N/U ratio ranges... 

Uranium and mixed uranium—plutonium nitrides have a potential use as nuclear fuels for lead cooled fast reactors (136—139). Reactors of this type have been proposed for use ia deep-sea research vehicles (136). However, similar to the oxides, ia order for these materials to be useful as fuels, the nitrides must have an appropriate size and shape, ie, spheres. Microspheres of uranium nitrides have been fabricated by internal gelation and carbothermic reduction (140,141). Another use for uranium nitrides is as a catalyst for the cracking of NH at 550°C, which results ia high yields of H2 (142). 

As previously stated, uranium carbides are used as nuclear fuel (145). Two of the typical reactors fueled by uranium and mixed metal carbides are thermionic, which are continually being developed for space power and propulsion systems, and high temperature gas-cooled reactors (83,146,147). In order to be used as nuclear fuel, carbide microspheres are required. These microspheres have been fabricated by a carbothermic reduction of UO and elemental carbon to form UC (148,149). In addition to these uses, the carbides are also precursors for uranium nitride based fuels. 

Uranium minerals, 25 396-397 Uranium mononitride, 25 427 Uranium nitrides, 25 426-427 Uranium ore concentrates, 25 407... 

In order to be used as nuclear fuel, carbide microspheres are required. These microspheres have been fabricated by a carbothermic reduction of UO3 and elemental carbon to form UC. In addition to these uses, the carbides are also precursors for uranium nitride based fuels. 

Gens, T. A. Helton, D. M. Clinton, S. D. Laboratory Preparation of Uranium Nitride Microspheres by a Sol-Gel Technique ORNL-3879, Oak Ridge National Laboratory Oak Ridge, TN, 1965. 

Uranium nitride UN has a theoretical density of 14.32 g/cm and melts around 2630°C. Made with N, UN has been suggested as an advanced fuel for fast reactors because of its high U atom density, low moderation, and high melting point. UN is made by reacting UH3 with the correct proportions of nitrogen or ammonia. UN reacts rapidly with moist air or water. 

Thorium and uranium are used in cotmnercial catalytic systems. Industrially, thorium is used in the catalytic production of hydrocarbons for motor fuel. The direct conversion of synthetic gas to liquid fuel is accomplished by a Ni-Th02/Al203 catalyst that oxidatively cracks hydrocarbons with steam. The primary benefit to the incorporation of thorium is the increased resistance to coke deactivation. Industrially, UsOs also has been shown to be active in the decomposition of organics, including benzene and butanes and as supports for methane steam reforming catalysts. Uranium nitrides have also been used as a catalyst for the cracking of NH3 at 550 °C, which results in high yields of H2. 

Titanium nitride Uranium nitride Vaiudium nitride Zirconium nitride... 

For purposes of limiting the scope of the thesis, the reactor will use a directly coupled closed Brayton cycle for power conversion and will use highly enriched Uranium Nitride fuel. The sections of the thesis will be ... 

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