Tunnel cave in at contamination site

11 May 2017

US - The U.S. Department of Energy (DOE) Richland Operations Office declared an emergency at the Hanford Site at approximately 8:30 a.m. May 9 after a cave-in of a 20ft (6m) section of a tunnel used to store contaminated materials.

The tunnel is located next to the Plutonium Uranium Extraction Plant, also known as PUREX, which is located in the center of the Hanford Site, in an area known as the 200 East Area.

DOE reported no contamination has been detected following the cave-in. “Crews are continuing to survey the area for contamination. Crews worked through the night to construct a gravel road to provide a stable and clear path for workers to access the hole in the tunnel. Workers are currently filling the hole with approximately 50 truckloads of soil, which will be used to fill the hole.”

In the 1950s and 1960s two tunnels were constructed next to a former chemical processing plant, PUREX. The tunnels were constructed of wood and concrete and covered with approximately 8ft of soil. The tunnels were constructed to hold rail cars that were loaded with contaminated equipment and moved into the tunnels during the Cold War.

During a routine surveillance of the area the morning of May 9, a 20ft-wide hole in the roof of one of the tunnels was observed, leading to the precautionary sheltering of employees and notifications to area counties and states. After no contamination was detected, the shelter in place order was lifted and employees were sent home from work early as a precaution. Workers continue to monitor the area for contamination as a crew prepares to fill the hole with clean soil.