Implementing a Direct-Feed Low-Activity Waste Capability in the Hanford Waste Treatment Plant - 18332

The original design of the Waste Treatment and Immobilization Plant (WTP) requires that all waste be processed through the Pretreatment (PT) Facility in order to separate the low-activity waste and high-level waste streams. The U.S. Department of Energy (DOE) has developed a sequenced approach to completing the WTP Project, beginning with feeding some liquid waste directly to the Low-Activity Waste (LAW) Facility, bypassing the PT Facility. Sending low-activity waste from the tank farms to the LAW Facility is referred to as direct-feed LAW (DFLAW). Under this plan, low-activity waste will be pretreated in the Hanford tank farms for cesium and solids separation to meet LAW Facility waste acceptance criteria and produce an acceptable low-activity waste product. The waste feed will then be transferred to the LAW Facility where it will be immobilized in glass, poured into stainless steel containers, and then transported by truck to the Integrated Disposal Facility, a mixed low-level waste disposal site located in the Hanford 200 East Area. The DFLAW operation will deliver about 1 million gallons of double-shell tank waste for treatment each year of operation, and nominally produce 21 metric tons of immobilized low-activity waste glass per day. The resultant freed space in the double-shell tanks will support safe tank farm operations and staging of additional waste for treatment. In December 2016 DOE executed a contract modification and approved a change to the project's performance baseline to complete the LAW Facility, Balance of Facilities (BOF), and Analytical Laboratory (LAB) and incorporate modifications needed to allow direct feed of low-activity waste to the LAW Facility. The contract modification and revised performance baseline support completion and hot commissioning of WTP facilities needed for DFLAW operations is as early as January 2022. DOE has made significant progress on design, equipment procurements, and civil construction of modifications required to implement the DFLAW capability in the WTP, including progress on civil construction of a new effluent management facility, which will process secondary liquid waste resulting from LAW Facility vitrification operations. (authors)