One more tank down, 140 to go - NBC Right Now/KNDO/KNDU Tri-Cities, Yakima, WA |

One more tank down, 140 to go

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RICHLAND, Wash. - The cleanup of Hanford will go on for years but Thursday workers completed another step forward. Washington River Protection Solutions said crews removed all the radioactive and chemical waste in a ninth single shell tank in the C-Farm.

This tank held 259,000 gallons of waste. It once had the second highest waste volume of all the single shell tanks in Hanford's C-Farm, including both plutonium and uranium. It took nearly two years to remove 99.5% of the waste from Tank C-104. One of 149 of the single shell tanks on the Hanford site.

"Retrieving the waste from this tank reduces the risk posed by having the waste stored in these underground tanks," said Lori Gamache, a spokesperson for the Department of Energy. "So we're one step closer to meeting our regulatory requirements of completing the retrieval by September of 2014 of all the tanks in the C-Farm."

Operators used modified sluicing to remove much of the waste and crews used a chemical soaking process by adding sodium hydroxide to the tank. That broke down and softened the stubborn material at the bottom. Once that reaction was complete, crews rinsed the tank with water.

"We always run across a number of challenges and C-104 was very challenging," said Rob Roxburgh of WRPS. "The exciting thing was that we were able to work together with the Department and with our very talented and able workforce to get this job done eight months ahead of schedule and more than three million dollars under budget."

Cleaning up this ninth single shell tank is yet another milestone in the Hanford cleanup. But it comes amid rumors of a new leak in the double shell tanks.

"We did discover material within the annulus of the double shell tank, which is the area between the primary and the outer liner of the tank," said Gamache. "The material is contained within the outer liner and poses no risk to the environment or the public."

Officials are not necessarily calling the material found in the double shell tank a leak. Crews are investigating and sampling the material and should have some answers by the end of this month.