Further tests to determine whether Hanford double-shell Tank AY-102 is leaking waste into the soil have been inconclusive, the Department of Energy said late last week. DOE has known since at least October that underground Tank AY-102, which holds 857,000 gallons waste, has an apparently slow leak from its interior shell. But until a month ago, DOE was confident that the leaked waste was being contained by the outer shell. On June 20 it began to suspect that the outer shell also might be leaking based on results of routine testing related to the tank’s leak detection pit. Since then, more water collected in the leak detection pit has been tested, a video inspection has been conducted and the pump used to remove water from the pit has be taken apart and analyzed. “Based on this testing, there is no conclusive indication of a leak from the secondary tank at this time,” DOE said in a statement.
But because of radiation readings taken in June, the Washington State Department of Ecology wants liquid waste removed from the tank. “Our position is despite the statement the tests are not conclusive the state has serious concerns about the high radiation reading June 20 and we believe work needs to begin immediately to pump liquids from this tank,” said John Price of the Department of Ecology. The state believes that removing liquid from the tank would reduce hydraulic pressure that may be contributing to the leak. The waste in the tank includes 706,000 gallons of liquid and 151,000 gallons of sludge. Although some of the liquid must remain because the radioactive waste in the tank generates heat, possibly 650,000 gallons or more could be safely removed. DOE has taken actions needed to prepare to immediately begin pumping the liquid from this tank “if warranted,” DOE said.
