A new report from U.S. Department of Energy confirms suspicions that the second tunnel at Hanford’s PUREX plant is at risk of collapse. That finding increases the urgency for Energy to quickly identify and implement a plan to stabilize both PUREX tunnels.

The report, as required by the Washington Department of Ecology’s recent enforcement order, examined the design of PUREX Tunnel No. 2 and found it is structurally deficient by almost every measure. The report also looked at Tunnel No. 1, and found that it, too, is structurally substandard. That became clear on May 9 when a portion of its roof collapsed.

“This makes it clear that the second tunnel may also pose a risk to human health and the environment,” said Alex Smith, Nuclear Waste Program manager for the Department of Ecology. “We took quick action in response to the Tunnel No. 1 collapse because of the potential for additional structural failures. We’re closely monitoring the situation to make sure Energy finds an effective solution.”

The report’s analysis is based on tunnel design specifications and does not include physical inspection or testing of actual tunnel conditions. For the next step, Ecology’s order requires Energy to submit a plan by Aug. 1 to, on an interim basis, stabilize the tunnels and the waste in them. Energy then has until Oct. 1 to submit a permit modification that demonstrates how it will ensure that the tunnels can safely store radioactive and dangerous wastes until the final cleanup and closure of the tunnels.

“We’re overseeing Energy’s response to the situation as it searches for solutions,” Smith said. “We reviewed and approved their proposal to inject grout (a form of cement) into Tunnel No. 1 as a way to stabilize the tunnel and the waste in it, and we’ll work with Energy to ensure that it finds a safe, workable strategy for Tunnel No. 2.”