Initial Selection of Supplemental Treatment Technologies for Hanford's Low-Activity Tank Waste

In 2002, the U.S. Department of Energy (DOE) documented a plan for accelerating cleanup of the Hanford Site, located in southeastern Washington State, by at least 35 years. A key element of the plan was acceleration of the tank waste program and completion of ''tank waste treatment by 2028 by increasing the capacity of the planned Waste Treatment Plant (WTP) and using supplemental technologies for waste treatment and immobilization.'' The plan identified specific technologies to be evaluated for supplemental treatment of as much as 70% of the low-activity waste (LAW). In concert with this acceleration plan, DOE, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology proposed to accelerate--from 2014 to 2006--the Hanford Federal Facility Agreement and Consent Order milestone (M-62-11) associated with a final decision on the balance of tank waste that is beyond the capacity of the WTP. The DOE Office of River Protection tank farm contractor, CH2M HILL Hanford Group, Inc. (CH2M HILL), was tasked with testing and evaluating selected supplemental technologies to support final decisions on tank waste treatment. Three technologies and corresponding vendors were selected to support an initial technology selection in 2003. The three technologies were containerized grout called cast stonemore » (Fluor Federal Services); bulk vitrification (AMEC Earth and Environmental, Inc.); and steam reforming (THOR Treatment Technologies, LLC.). The cast stone process applies an effective grout waste formulation to the LAW and places the cement-based product in a large container for solidification and disposal. Unlike the WTP LAW treatment, which applies vitrification within continuous-fed joule-heated ceramic melters, bulk vitrification produces a glass waste form using batch melting within the disposal container. Steam reforming produces a granular denitrified mineral waste form using a high-temperature fluidized bed process. An initial supplemental technology selection was completed in December 2003, enabling DOE and CH2M HILL to focus investments in 2004 on the testing and production-scale demonstrations needed to support the 2006 milestone.« less