RICHLAND, Wash. -

Some workers at a Hanford Nuclear Reservation tank farm have had their skin contaminated with low levels of radioactive waste.

The incident occurred Tuesday morning.

The Tri-City Herald reports the workers were in a pit at the AX Tank Farm when contamination was detected in the pit.

They backed out of the area, but a survey found low levels of radioactive contamination on their skin.

Equipment is being installed in the AX Tank Farm to allow waste to be emptied from leak-prone, underground nuclear waste storage tanks.

Hanford for decades made plutonium for nuclear weapons and now is cleaning up a vast quantity of radioactive waste from that work.