The Department of Energy has confirmed that its oldest double-shell tank is actively leaking radioactive and hazardous chemical waste from its inner shell.
DOE made the announcement Monday after a video inspection of the area between the shells Sunday showed more waste in one place than a video taken Thursday showed.
"It's a very, very small volume," said Tom Fletcher, DOE assistant manager for the tank farms. Although there's no good way to measure the amount, it could be a couple of tablespoons of additional waste between the video inspections.
Tank AY-102 is the first of Hanford's double-shell tanks known to have leaked waste from its inner shell.
The Hanford nuclear reservation has 28 double-shell tanks that are being used to hold waste from older single-shell tanks, many of which have leaked in the past. Together, the two types of underground tanks hold 56 million gallons of radioactive waste left from the past production of plutonium for the nation's nuclear weapons program.