Hanford workers resumed emptying Tank C-101 of radioactive and hazardous chemical waste Friday.
Next week pumping also should resume on the second tank where work has been under way at Hanford, Tank C-110. Work to pump waste from single-shell tanks into newer double-shell tanks stopped Aug. 21 when an emergency alert was declared.
Hanford officials feared that a gasket had failed in a system being used to retrieve waste from Tank C-101, allowing waste to leak. But the cause of an unusual radiation reading was discovered to be a small amount of previous contamination that inadvertently had become uncovered.
The Department of Energy faces a court-enforced consent decree to have seven more single-shell tanks emptied before October 2014.