DOE: Increased risk of another tunnel collapse at Hanford PUREX Site
RICHLAND, Wash. – A new federal report shows increased risk of a tunnel collapse at Hanford's PUREX site. That finding increases the urgency for the U.S. Department of Energy to quickly identify and implement a plan to stabilize both PUREX tunnels.
"The risk of a future collapse of Tunnel 2 is high,” said Doug Shoop, DOE Richland Operations Office manager. “That’s based on the stresses of several of the structural components of the facility."
A review of tunnel’s 1960s design showed that it does not meet current codes for structural integrity, and that it may not be able to bear the weight of the soil above the tunnel, according to the report for Tunnel 2. The report finds that Tunnel 2 is identified as presenting a high potential for localized collapse.
This report follows the partial collapse of Tunnel 1 in May, compromising its structural integrity.
Now, leaders at the Department of Energy Richland Operations office and Washington Department of Ecology said Tunnel 2 is structurally deficient by almost every measure.
"Tunnel 2 should be stabilized as soon as possible," Shoop said.
Washington Department of Ecology's recent enforcement order prompted these examinations.
"For Tunnel 2, we were not surprised to find that it was at risk of collapse, but it’s very concerning to us," said Alex Smith, Nuclear Waste Program manager for the Department of Ecology.
Smith said the second tunnel may pose a risk to human health and the environment.
“We took quick action in response to the Tunnel 1 collapse because of the potential for additional structural failures,” she said. “We’re closely monitoring the situation to make sure Energy finds and effective solution.”
She stressed that Ecology will talk to Congress pointing out that these issues highlight why there needs to be adequate funding for the Hanford cleanup.
Sen. Ron Wyden, (D- Ore.) shared his reaction to the reports Friday.
"The reports made public today indicate that another tunnel collapse is just waiting to happen,” Wyden said. "These tunnels are not safe and have literally been out of sight and out of mind. My colleagues and I have asked the Government Accountability Office to take a closer look at the Department of Energy's failure to clean up these tunnels and other radioactive waste sites at Hanford. I'm calling for action now in order to protect Hanford workers, the public and the environment from this ongoing threat."
Tunnel 2 was built of metal and concrete in 1964 and is approximately 1,700 ft. long with 28 rail cars stored inside. The waste on these rail cars is similar to the waste in Tunnel 1, including equipment from Hanford’s plutonium processing facilities and other plutonium processing waste. The waste includes both radioactive elements and chemicals such as lead, cadmium and barium.
"All of these materials, structures that are holding on to waste out there at the site are starting to get older and all getting past their useful life, and we want to make sure we don't have incidents like this or we can do what we can to prevent them," Smith said.
DOE currently believes the risk to employees and the environment from a collapse of Tunnel 2 is minimal given that collapsed soil would prevent or minimize any potential release of radioactive contamination.
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.
Tunnel 1, approximately 350 ft. long, was covered with a plastic tarp following the initial collapse to protect it from further degradation.
“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 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 2.”
Shoop said filling Tunnel 1 could cost anywhere from $4-7 million and it will be completed by the end of the calendar year.