Kinetic Studies of the Reaction of Plutonium Hydride with Oxygen

Kinetics for the reaction of oxygen with plutonium hydride have been measured in oxygen at 1.33 kPa and over a temperature range of 90 to 360°C. The initial reaction takes place with a very low activation energy and is limited by the formation of a protective oxide film. The protective nature of the oxide film product is dependent on the temperature. Once the oxide film is formed, the oxidation reaction is a linear process controlled by oxygen diffusion. Measurements were conducted on hydrides prepared from pure plutonium as well as a plutonium/gallium alloy.