Oxygen Uptake Using a Nickel Catalyst

A Zirconium-iron alloy is used to absorb tritium that has escaped from process systems at LLE. Oxygen deactivates the alloy and decreases its ability to remove tritium from effluent streams. A nickel catalyst is used to crack tritiated hydrocarbons and to capture elemental oxygen. The capacity of nickel beds is finite and they require periodic reactivation using hydrogen in a helium carrier stream. Experiments have been conducted to study the efficiency of oxygen uptake and the efficiency of reactivation. Increasing the temperature of the catalyst from room temperature to 400 O C increases the amount of oxygen that can be absorbed by the catalyst. Catalyst reactivation is more efficient as the flow rate of hydrogen increases. Water vapor in the vicinity of the nickel inhibits reactivation; increasing the carrier flow rate decreases the water vapor pressure and improves the reactivation efficiency. 1