12b Oxidative Processes for Treating High Level Waste Sludge

Reid Peterson, Brian Rapko, and Serguei Sinkov. Pacific Northwest National Laboratory, Richland, WA 99352

A significant amount of chrome is present in High Level Waste (HLW) sludge in the tank farms at the Hanford nuclear reservation in Richland Washington. Most of this chrome is present as insoluble Cr3+. A primary focus of the Waste Treatment Plant currently under construction at Hanford is the turn the HLW sludge into a glass waste form. However, inclusion of chrome in the glass waste form can lead to a significant increase in glass volume. Therefore, a number of processes have been evaluated to remove chrome by oxidizing the chrome to more soluble Cr6+. This paper will provide an engineering evaluation of the various options for oxidizing chrome and evaluate the benefits of the potential options for the various types of waste that require processing by the Waste Treatment Plant