(247b) The Hanford River Protection Project Reference Integrated Flowsheet

Approximately 56 million gallons of radioactive and hazardous waste is stored in underground tank farms at Hanford in southeastern Washington State.  This waste arose from the production of plutonium during the Second World War and Cold War for use in nuclear weapons.  The waste is currently in the form of slurries, precipitated salts and concentrated salt solutions but needs to be treated and immobilized into a form suitable for disposal.  The River Protection Project (RPP) is the plan agreed to by the State of Washington, the Federal Government and the Environmental Protection Agency.  The RPP intends to retrieve the waste, separate it into high and low radioactive portions and vitrify both for disposal.  The low radioactive portion will be dispositioned at Hanford in a near-surface, engineered repository while the highly radioactive portion will be dispositioned in a federal geologic repository.  Key to this strategy is the Waste Treatment and Immobilization Plant (WTP), currently under construction at Hanford.  As the Hanford Tank Farms and the WTP transition to an operational phase, there is a need to develop process flowsheets to support their operation.  These flowsheets are multi-level in that they become progressively more detailed as the perspective moves from the RPP mission to individual facility and then unit process operation levels.  The Tank Waste Disposition Integrated Flowsheet (TWDIF) activity was initiated to define these flowsheets and the means by which they can be optimized through identifying and closing gaps, mitigating risks and realizing opportunities.