RICHLAND, Wash. (AP) - New test results show that monitoring for airborne radioactive contamination has not protected some Hanford Nuclear Reservation workers demolishing the Plutonium Finishing Plant.

The U.S. Department of Energy says two more Hanford workers have inhaled or ingested small amounts of airborne radioactive material, with tests for 180 workers still pending.

The Tri-City Herald reports the most recent results were for the first 91 workers who requested testing after a spread of radioactive material in mid-December.

In addition, air samples collected at sites outside the demolition zone show that airborne radioactive contamination was not found in 2017 by other monitoring methods meant to more quickly warn of a potential danger to workers.

Hanford for decades made plutonium for nuclear weapons and workers are now cleaning up the site.