RICHLAND, Wash.—Washington River Protection Solutions (WRPS), the Hanford tank operations contractor for the U.S. Department of Energy Office of River Protection, is using a portable exhauster to remove excess liquid from Tank T-111.
WRPS recently completed a 30-day test run of the exhauster, and initial results show liquid is being evaporated at a rate of about 25 to 30 gallons per day.
The exhauster has removed nearly 1,000 gallons of water from T-111 during the test run, and another 1,000 gallons have been removed through Sept. 28. In-tank images show visible changes in the waste surface and liquid-level data confirm the decrease.
“The exhauster is performing as we hoped it would,” said Mark Lindholm, WRPS president and project manager. “This is an important step in the right direction as we try to minimize liquid inside T-111.”
The volume of surface liquid in the tank is estimated to be between 2,500 and 4,000 gallons. The exhauster will also remove liquid in the top few inches of the sludge waste remaining in the tank.
The liquid in the tank is a combination of intrusion water and residual liquid remaining from interim tank stabilization in the mid-1990s.
Although exhausters have been used in the past to evaporate excess liquid from single-shell tanks, this is the first exhauster system WRPS has used for single-shell tank intrusion mitigation. This approach removes liquid from single-shell tanks that are known or suspected leakers.
T-111 is considered a leaking tank and contains about 436,000 gallons of sludge waste. The tank was first declared of questionable integrity in 1974 and most of the supernatant liquid was removed.
If deemed successful, a similar approach might be used in more than two dozen other single-shell tanks with visible liquid.