Effect of porosity on the manufacturing of U3O8-Al dispersion fuel plates

The pore volume present in the starting fuel meat of dispersion fuel plates influences the behavior of its deformation during the fuel plate fabrication by rolling to a great extent. This study was carried out to investigate the influence of pore content in the starting fuel meat on the manufacturing of aluminum-base dispersion fuel plates. Factors that affect the residual porosity present in the meat of the fuel plate were investigated. Results showed that the residual pore volume of aluminum-base dispersion-type U3O8-Al fuel plates depends on the characteristics of the starting fuel meat, which is fabricated by pressing. The residual pore volume depends on the U3O8 concentration. For a particular U3O8 concentration, the rolling process establishes a constant pore volume, which is called equilibrium porosity. The equilibrium porosity is insensitive to the initial pore volume present in the starting fuel meat. The research showed that fuel meat integrity was greatly influenced by the initial porosity of the fuel meat. U3O8-Al dispersion fuel plates were successfully fabricated with uranium loading above 3.0 gU/cm3. This uranium loading is equivalent to the one used in the U3Si2-Al dispersion fuel, currently operating at the IEA-R1 research reactor of the Nuclear and Energy Research Institute - IPEN/CNEN-SP. The U3O8-Al dispersion fuel can substitute the silicide fuel with advantages such as lower price and simpler manufacturing process.