Segregation of Uranium Metal from K Basin Sludge: Results from Vendor Testing

Abstract

Under contract to Fluor Hanford (FH), Pacific Northwest National Laboratory (PNNL) directed laboratory, bench-scale, and pilot-scale vendor testing to evaluate the use of commercial gravity mineral concentration technology to remove and concentrate uranium metal from Hanford K Basin sludge. Uranium metal in the sludge corrodes by reacting with water to generate heat and hydrogen gas, and may constrain shipment and disposal of the sludge to the Waste Isolation Pilot Plant (WIPP) as remotehandled transuranic (RH-TRU) waste. To meet the hydrogen gas concentration criterion specified for shipment to WIPP, the uranium metal in the sludge must be removed, oxidized, or otherwise rendered unreactive. These other options may include removing the water from the sludge or preventing the uranium metal from coming in contact with the water. Separating dense uranium metal from the K Basin sludge is expected to be similar to some physical gold recovery operations. Consequently, the capabilities of commercial gravity mineral concentration technologies were assessed for their applicability to K Basin sludge streams. The testing discussed here was conducted (in air) separately by two vendors (Gekko Systems,