He³ Outgassing from Four Working Palladium and Uranium Beds

The He³ output from two palladium and two uranium beds that store T₂ and D-T was studied as a function of time. Three of the beds were started new and watched for 1 yr; the fourth bed was 12 yr old. All four beds were used in routine tritium handling. Initial stoichiometries were PdT_0.3 and UT_0.7 so that both operated at similar pressures from 1 to 130 kPa. The He³ from palladium ranged from the 0.002 mol% lower level of sensitivity to 0.01% for Pd/T₂ at 1 yr of age. The U/T system showed 0.1% He³ at 4 to 62 days and 0.1 to 10% at longer times, with the first cuts being high in He³. The palladium bed with 95 to 97% pure T₂ enriches the output to as high as 97 to 99%.