A convoy of trucks has begun this week to fill a Hanford radioactive waste storage tunnel that is at risk of collapse, but a Seattle watchdog group is attempting to halt the work.
On Sept. 28, the Washington state Department of Ecology, a Hanford regulator, gave the Department of Energy approval to start filling the second PUREX plant waste storage tunnel with concrete-like grout.
Seattle-based Heart of America Northwest expects to appeal.
It has 30 days from Ecology’s decision to file an appeal with the Washington state Pollution Control Board. Other legal action also is a possibility, said Gerald Pollet, executive director of Heart of America.
About 5,000 truckloads of grout will be needed to fill the tunnel, with an inch or two of grout added at a time and allowed to harden before more is added.
The Department of Ecology was pressured by DOE and Tri-City-area mayors to skip public meetings and a public comment period to let the grouting begin in early September to finish before the worst of the winter weather.
They were concerned that a video inspection of the interior of the tunnel showed deterioration in one end of the tunnel that increased its risk of collapse, potentially allowing radioactive particles to become airborne.
But Alex Smith, manager for Ecology’s Nuclear Waste Program, refused.
“Communities in Washington state have a right to review and weigh in on important Hanford decisions,” including the irreversible act of filling the tunnel with grout, she said.
Ecology finished its 45-day public comment period the night of Sept. 27 and the next day gave its approval for the project.
Ecology said it carefully reviewed more than 70 comments as they came in, including Heart of America’s comment, before authorizing the work. Heart of America submitted a 10-page document outlining its objections to grouting the day the comment period closed.
Pollet said that not taking even one day for a full review “is the most outrageous and insulting disregard of public comment in the sad history of Hanford cleanup.”
The mayors of the three Tri-Cities and West Richland said grouting should be done as soon as possible to reduce the risk to the region of a potentially catastrophic tunnel collapse.
But Pollet said the risk of failure could be reduced short of filling the tunnel with grout.
In May 2017, the shorter and older of the two PUREX processing plant waste storage tunnel partially collapsed, but released no airborne radiation as dirt topping the tunnel fell in to cover its contents. It holds eight rail cars loaded with failed and obsolete contaminated equipment.
The tunnel, which was built in the ‘50s from timbers, was filled with grout under emergency conditions with no public comment within six months of the partial collapse.
A wet and snowy winter may have been a factor in the collapse, saturating the eight feet of soil above the tunnel and adding to the weight on its flat roof.
Pollet said the risk of collapse this winter for the second tunnel, built in the ‘60s in an arch shape with concrete and steel reinforcement, could be reduced by measures such as tenting it to keep precipitation off its top.
Another option could addressing the end of the tunnel where corroded steel was spotted during a video inspection, possibly by filling it with sand that could be more easily removed than grout, he said.
Filling the second tunnel with grout could make legal disposal of the waste it holds impossible, he said. The tunnel likely includes high level radioactive waste or waste with plutonium contamination, both of which should go off site to deep national geological repositories, he said.
DOE has said it is possible to eventually make strategic cuts around railroad cars to saw the grout into large blocks and then lift them out of the tunnel for disposal.
Pollet started this week by appealing to Gov. Jay Inslee, asking him to immediately withdraw approval for grouting.
The governor’s office released a statement Wednesday saying it supports the Department of Ecology’s decision “to ensure that the tunnel is stabilized, workers and communities are protected, and we don’t have another collapse.”
Ecology said that it approved grouting after agreeing with DOE that the second tunnel is structurally unsound and does not meet engineering standards to support the eight feet of dirt on its top designed to shield radiation.
A collapse could result in the release of radioactive contaminants, potentially endangering workers and the environment, it said.
A final cleanup decision is yet to be made on the tunnel. But if the decision is to remove the waste, DOE would have to first fill the tunnel with concrete to shield workers from radiation, the Department of Ecology said.
Heart of America said in its comments submitted in September that Ecology should require an enforceable timeline for removal of the waste from the tunnel in three to five years.
The Department of Ecology said that a process to determine the final cleanup plan for the tunnel is planned to start in 2020.