A leaking waste tank at the nation's most contaminated nuclear site is raising new concerns about delays in cleaning up the Washington site.
The U.S. Department of Energy says liquid levels are decreasing in one of 177 underground tanks at the Hanford nuclear reservation, though it's not clear by how much.
The tanks hold millions of gallons of a highly radioactive stew left from decades of plutonium production for nuclear weapons.
The agency says monitoring wells near the tank have not detected higher radiation levels.
Gov. Jay Inslee said Energy Secretary Steven Chu say the federal government must not waiver in its commitment to clean up the highly contaminated site.
A plant under construction to treat the waste is billions of dollars over budget and years behind schedule.