Cleanup workers have taken a big step in cleaning up a plant on the Hanford nuclear reservation that processed plutonium for nuclear weapons.

They have removed a section of gloveboxes that weighed 10 tons. Gloveboxes protected workers handling radioactive material.

The Tri-City Herald reports more than 200 gloveboxes are being dismantled and buried as the Plutonium Finishing Plant is demolished.

The plant operated for 40 years, starting in 1949. Cleanup plans call for workers to finish demolition in 2016.

The 10-ton piece was so big, workers started practicing for the job in January on a mock-up.