Uranium nitrides
Uranium nitrides is any of a family of several ceramic materials: uranium mononitride (UN), uranium sesquinitride (U2N3) and uranium dinitride (UN2). The word nitride refers to the −3 oxidation state of the nitrogen bound to the uranium.
| Names | |
|---|---|
| IUPAC name
Uranium nitride | |
| Identifiers | |
| ChemSpider | |
PubChem CID |
|
| |
| Properties | |
| U2N3 | |
| Molar mass | 518.078 g/mol |
| Appearance | crystalline solid |
| Density | 11300 kg·m−3, solid |
| Melting point | 900 to 1,100 °C (1,650 to 2,010 °F; 1,170 to 1,370 K) (decomposes to UN) |
| Boiling point | Decomposes |
| 0.08 g/100 ml (20 °C) | |
| Structure | |
| Hexagonal, hP5 | |
| P-3m1, No. 164 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Uranium nitride has been considered as a potential nuclear fuel and will be used as such in the BREST-300 nuclear reactor currently under construction in Russia. It is said to be safer, stronger, denser, more thermally conductive and having a higher temperature tolerance. Challenges to implementation of the fuel include a complex conversion route from enriched UF6, the need to prevent oxidation during manufacturing and the need to define and license a final disposal route. The necessity to use expensive, highly isotopically enriched 15N is a significant factor to overcome. This is necessary due to the (relatively) high neutron capture cross-section of the far-more-common 14N, which affects the neutron economy of a reactor.