Method of manufacturing sinter-active U3O8 powder and method of producing nuclear fuel pellets utilizing the same
US8449795B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 29, 2007 |
| Grant date | May 28, 2013 |
| Priority date | — |
| Expiry date | Aug 30, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
There is provided a method of producing U3O8 powder having large surface area and small particle size by oxidizing defective UO2 pellets and manufacturing nuclear fuel pellets which are stable in a pore structure and high in density through the use of a mixture comprising UO2 powder and U3O8 powder. The method includes producing an U308 powder having a surface area of at least 1 m2/g by oxidizing defective UO2 pellets at a temperature of 300 to 370° C. in such a way that a maximum weight increase rate per 1 g of the UO2 pellets is up to 0.06 wt %/min; producing a mixed powder by mixing the U3O8 powder with an UO2 powder by 2 to 15 wt %; producing a compact by compression molding the mixed powder; and sintering the compact in a reducing gas atmosphere at a temperature of 1600 to 1800° C. In addition, a small amount of an Al-compound may be added to the oxidized U3O8 powder before the U3O8 powder is mixed with the UO2 powder. The additive such as Al is mixed with the U3O8 powder and then mixed with the UO2 powder to produce the pellets by a conventional production method. This ensures a stable pore structure, high density and a considerable increase in a crystal grain size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.