At 8:26 a.m. on May 9, 2017, the U.S. Department of Energy (DOE) Richland Operations Office activated the Hanford Emergency Operations Center after an alert was declared.  In particular, officials responded to reports of a cave-in of a 20-foot section of a tunnel that is hundreds of feet long that is used to store contaminated materials.  The tunnel is located next to the Plutonium Uranium Extraction Facility, also known as PUREX, which is located in the center of the Hanford Site in an area known as the 200 East Area.

Overview  During a routine surveillance of the area in the morning, a 20-foot-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.

Actions taken to protect site employees included the following:

•   As a precaution, workers in the vicinity of the PUREX facility—as well as the Hanford Site north of the Wye Barricade (southern entrance to the site)—were told to shelter in-place.

•   Access to the 200 East Area of the Hanford Site, which is located in the center of the Hanford Site, has been restricted to protect employees.

All personnel in the vicinity of the PUREX facility were accounted for and there were no reports of injuries.

Background  In the 1950s and 1960s, two tunnels were constructed next to the PUREX former chemical processing plant.  The tunnels were constructed of wood and concrete and covered with approximately 8 feet 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.

The approximately 360-foot-long tunnel where the partial collapse occurred contains 8 rail cars loaded with contaminated equipment.  That tunnel feeds into a longer tunnel that extends hundreds more feet and contains 28 rail cars loaded with contaminated equipment.  The hole opened up in the shorter tunnel near where it joins the longer tunnel.  The tunnels were sealed in the mid-1990s and are checked periodically.

DOE hosted a briefing on its Hanford Site Facebook channel.  Interested stakeholders can view the briefing on the Hanford Site Facebook page at https://www.facebook.com/HanfordSite/.