The Hanford Nuclear Reservation says a 20-foot section of a tunnel system where it stores contaminated material and equipment collapsed today, sparking an emergency alert and restrictions on workers’ movements. No injuries were reported.
A remotely operated TALON robot surveyed the scene and detected no release of contamination, Hanford said in its online update on the emergency.
Hanford said workers conducting routine surveillance this morning discovered the 20-by-20-foot hole in the roof of one of the two storage tunnels at the Plutonium Uranium Extraction Plant, or PUREX Plant, in the site’s central 200 East Area.
The tunnels were constructed of wood and concrete during the Cold War, and covered with about 8 feet of soil. They’ve been used for decades to store contaminated equipment from plutonium production operations at the site in southeastern Washington state.
The cave-in occurred in the 200 East Area, around a spot where the two tunnels join together, Hanford said.
The workers on the surveillance team were evacuated, and thousands of employees sheltered in place for hours. As of this afternoon, all non-essential employees at the Hanford site have been released, officials said in a tweet.