Activated Sintering of Uranium Dioxide Fuel, (III)

Roles of niobium pentoxide, vanadium pentoxide and titanium dioxide in the grain growth and sintering of uranium dioxide

Pure uo2 sinters readily at temperatures below 1600°c when non-stoichiometric oxygen introduced during the presintering treatment is available for diffusion and subsequent densification. In the absence of excess oxygen sintering occurs at temperatures above 1600°C by self-diffusion of stoichiometric oxygen in uo2 • Grain growth occurs when open porosity has been eliminated and is controlled by ...

Thermal -Hidraolyc Study of Trr Core in Fuel Conversion Frome Highly Enriched Uranium to Low Enriched Uranium Fuel (RESEARCH NOTES)

Configurational analysis of uranium-doped thorium dioxide

While thorium dioxide is already used industrially in high temperature applications, more insight is needed about the behaviour of the material as part of a mixed-oxide (MOX) nuclear fuel, incorporating uranium. We have developed a new interatomic potential model, commensurate with a prominent existing UO2 potential, to conduct configurational analyses of uranium-doped ThO2 supercells. Using th...

Carbon dioxide reduction and carbon monoxide activation employing a reactive uranium(III) complex.

The highly reactive, six-coordinate tris-aryloxide U(III) species, [((t-BuArO)3tacn)U] (1) reacts with CO2 in a 2e- reduction to produce CO and a dinuclear U(IV/IV) mu-oxygen bridged complex [{((t-BuArO)3tacn)U}2(mu-O)] (2). This reaction proceeds via a dinuclear CO2-bridged intermediate 3. Also, mononuclear 1 was treated with 1 atm of CO to yield dinuclear [{((t-BuArO)3tacn)U}2(mu-CO)] (4) wit...

Molten uranium dioxide structure and dynamics.

Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating,...