Cleaning up the Legacy of Nuclear Weapons Production: Progress and Challenges at the Hanford Site

The Hanford Site in southeast Washington State developed out of the Manhattan Project in the early 1940’s and ultimately produced two-thirds of the United States plutonium for nuclear weapons. The nuclear materials derived from Hanford’s nuclear reactors and chemical processing plants also generated large volumes of chemical and radioactive wastes. Planned and unplanned releases of waste to the environment resulted in contamination of soil and groundwater.  Clean-up of the Hanford Site began in earnest in 1989 after the US Department of Energy, US Environmental Protection Agency, and the Washington State Department of Ecology entered into a Federal Facility Compliance Agreement (FFCA), also known as the Tri-Party Agreement to clean up the Hanford Site

Today, more than thirty years into the cleanup, significant progress is visible across major portions of the Hanford Site. Lands straddling the Columbia River that were home to nine production reactors are largely cleaned up, most major facilities removed or stabilized for future disposition, contaminated soils have been removed and disposed in a permitted facility distant from the river, and groundwater remediation is ongoing to remove and contain contaminants that had threatened the river. Inland from the Columbia River on the “Central Plateau” highly radioactive waste from reprocessing plants is stored in large, aging underground waste tanks, awaiting start-up of the worlds largest nuclear waste processing facility – the Waste Treatment and Immobilization Plant (WTP). WTP design and construction has been plagued by numerous challenges that have delayed the mission.  A phased startup of the liquid waste treatment portion of the plant will enable tank waste processing to begin over the next few years.  The diversity and magnitude of stored tank wastes requiring treatment as well as the extent and nature of subsurface contamination contribute to the complexity of the cleanup challenge at Hanford.