RICHLAND, Wash. - Washington River Protection Solutions (WRPS), the tank operations contractor for EM’s Office of River Protection, is wrapping up waste retrieval activities at the last tank to be retrieved at Hanford ’s C Tank Farm.
WRPS has completed retrieval operations in waste storage tank C-105 to the limits of three technologies.
It’s the 16th and final tank in C Farm to be retrieved under legal agreements governing cleanup activities at Hanford between DOE and the Washington Department of Ecology. C Farm was among four Hanford tank farms constructed during the Manhattan Project.
Workers safely removed approximately 120,000 gallons of radioactive and chemical waste from the 530,000-gallon-capacity tank and transferred it to one of Hanford’s double-shell tanks. An estimated residual waste volume of 4,800 gallons remains in Tank C-105.
The next steps are to finish video measurements and sampling of the residual tank waste.
“The teamwork between the Office of River Protection, the Department of Ecology, and WRPS has been key to the success of this complex and hazardous project," said Mark Lindholm, WRPS president and project manager. “The lessons learned will be used in future tank retrievals."
WRPS began retrieving waste from C-105 in June 2014 using the Mobile Arm Retrieval System (MARS) with a vacuum nozzle. MARS retrieved more than 92,000 gallons of waste by September 2015 before reaching the end of its service life. ORP replaced MARS with two remotely controlled, extended-reach sluicers to retrieve remaining tank waste.
WRPS finished retrieving an estimated 30,375 gallons of hardened sludge material this year. The process involved sluicing with liquid waste and high-pressure water, water rinsing, and caustic dissolution. The water and highly caustic solutions softened and dissolved the waste, allowing hard-to-retrieve material to be mobilized and pumped to a double-shell tank farm.
“I can’t say enough great things about our employees and subcontractors," Lindholm said. “They demonstrated a strong commitment to safety, creative thinking, and hard work while working in challenging conditions on a daily basis."
Tank C-105 operated from 1947 through 1980, serving as a receiver tank for Plutonium Uranium Extraction Plant (PUREX) supernate wash waste and PUREX sludge supernate from A and AX tank farms in the late 1960s to 1970s. During this time, C-105 was used as the feed lag storage tank for the ion exchange system in B-Plant.
Source: U.S. Dept. of Energy, Office of Environmental Management
