The Washington State Department of Ecology has extended the deadline for the Department of Energy to provide a plan to empty Hanford Tank AY-102.
The nuclear reservation's oldest double-shell tank is leaking radioactive waste between its shells.
The state demanded in January that DOE produce a plan by Feb. 15 to pump waste from the tank. But at a request from DOE, the state has extended the due date to March 7.
Tank AY-102 was discovered to have an interior leak more than a year ago and DOE's delay in taking action has been "unacceptable," according to the state.
State regulations require DOE to inspect the tank to determine the cause of the leak, including removing as much of the waste as necessary to allow for the inspection, within 24 hours or as early as possible.