To prevent it from collapsing, the Department of Energy wants to start filling a second PUREX plant waste storage tunnel at the Hanford site with concrete-like grout in August — before the end of a scheduled public comment period about the effort.
The Washington State Department of Ecology, lead state regulator at Hanford, plans a 45-day public comment period and two public meetings on the grouting plan, starting next month.
But DOE has asked the state to authorize, by July 23, 180 days of grouting work. The state will review the request and respond, Ecology spokesperson Randy Bradbury said.
Bradbury said there is no timeline for the state to act but that regulations require approval or denial as quickly as practical. He also said the state plans to proceed with its public involvement process. DOE already went through its own public comment period.
A shorter PUREX plant waste storage tunnel partially collapsed in May 2017, and DOE has concluded that the second, longer tunnel is also at high risk of collapse.
DOE said Monday it needs to start work next month to stabilize the tunnel before winter, when grout trucks would have to travel over icy and snowy roads.
The second, longer PUREX tunnel holds 28 rail cars loaded with highly contaminated equipment.
After it partially collapsed, DOE filled the first PUREX tunnel with 521 truckloads of grout in six weeks. Ecology approved the work without a public comment process, given the emergency conditions. The first tunnel holds eight rail cars loaded with highly radioactive, obsolete equipment from the PUREX plant.
Grouting the tunnels is only an interim stabilization method; DOE has yet to decide on a final cleanup method for the tunnels, and the waste inside them.
