The helium coolant of a high temperature nuclear power reactor (HTR) operating in the temperature region 570 to 1220 K has to be purified from impurities such as H2, N2, CO, CO2, H2O and CH4. Also tritium has to be removed especially in the case of the process heat reactor to minimize contamination of product gases. Cerium misch metal was investigated as getter material at 570 K under near realistic conditions. The results show that this method can become an effective, alternative gas purification system. Carbon monoxide gives some concern if it is present in high concentrations by partially passivating the material. But the getter bed can easily be re-activated by a heating process.

Measurements with tritium injection showed that not all tritium is being gettered. Probably some species (possibly CH3T) are formed which are not as readily absorbed as tritium in form of T2, HT or HTO. Work in this field is going on to clarify this effect.