State approves federal plan to stabilize second Hanford tunnel containing radioactive equipment

State regulators have approved a request by the U.S. Department of Energy to begin work stabilizing a tunnel at Hanford Nuclear Reservation that contains rail cars loaded with radioactive equipment and is similar to the tunnel that collapsed in May 2017.

The Washington Department of Ecology approved the request after a 45-day public comment period, according to a news release. The approval clears the way for federal contractors to immediately begin filling the second tunnel with grout, which is a type of concrete.

“We’ve received many thoughtful, well-founded criticisms of grouting,” Alex Smith, manager for Ecology’s Nuclear Waste Program, said in the release. “But in the end, we must protect Hanford workers and the surrounding communities and environment.”

The work will be done on the second of two Plutonium-Uranium Extraction Plant tunnels that both contain rail cars with radioactive equipment that was used decades ago to extract plutonium from nuclear fuel rods. A portion of Tunnel 1’s roof collapsed in May 2017 and prompted an evacuation.

That tunnel was filled with grout to prevent further collapse. The new work will do the same to Tunnel 2. However, decisions on how to do a final cleanup of Tunnel 2 won’t be made until 2020 and could take several years to complete.