Hanford’s PUREX Tunnel 2 no longer poses a threat of collapse
Congratulations to the U.S. Department of Energy (Energy) for quickly and safely completing its mission to stabilize the tunnel by filling it with concrete. We're now starting to work with Energy to determine the ultimate fate of the tunnel’s highly radioactive contents.
It might seem to have been a simple, easy solution: after the roof of a tunnel containing radioactive waste partially collapsed, workers filled that tunnel (Tunnel 1) and its much larger and longer companion (Tunnel 2) with concrete to prevent any possibility of further collapses.
But, like most things Hanford, the decisions we made regarding the PUREX tunnels were neither simple nor easy.
Here’s a recap
- On May 9, 2017, Hanford workers discovered an 8-foot hole in the roof of Tunnel 1, exposing its highly radioactive contents and potentially releasing radioactive contaminants into the air (fortunately, no releases were detected).
- Within 24 hours, we ordered Energy to quickly determine the cause of the collapse and develop a plan to address it. The order covered both tunnels.
- Energy said the best emergency solution was to fill Tunnel 1 with concrete. We approved that plan, and by the end of the year the tunnel was filled.
- After video inspection inside Tunnel 2 and a study by a national panel of experts, Energy concluded that the second tunnel also was at serious risk of collapse, and that, again, concrete was the best solution.
- We eventually approved the plan for Tunnel 2. Work to fill Tunnel 2 began last fall and has just now successfully concluded.
Strong views on both sides
There were passionate arguments both for and against using concrete in Tunnel 2.
We stand by our decision. But we listened to, and understood, those who disagreed.
Critics of using concrete made their objections known almost from the beginning. They had valid concerns — chief among them the fear that, once encased in concrete, the tunnel waste will never be moved.
Another major issue was the public’s ability to influence the decisions.
While we vigorously support the public’s right to comment on major Hanford cleanup decisions, the gaping hole leading to a tunnel filled with radioactive waste — and the very real threat of further collapses — justified an emergency response for Tunnel 1. We held a joint public information meeting with Energy, but it was not a traditional public comment session, and work on the tunnel proceeded on an emergency basis.
Ensuring time for public comment
Still, we insisted on two things (among others): that the concrete be formulated such that it could be cut into blocks and eventually removed; and that we go through the full public comment process to determine the best course for Tunnel 2.
We worked closely with Energy to expedite work on Tunnel 1. After the panel of experts recommended concrete for Tunnel 2, Energy held a public comment period and meeting in early 2018.
For this kind of work on Hanford, the process is clear and has been used countless times. Energy proposes a permit change to allow new work, then holds a comment period. We review the proposal and the public comments, ask for changes and necessary documentation, then we hold a comment period. Then we review the proposal and the new comments received, make any required changes, and issue (or deny) the permit.
For Tunnel 2, several months elapsed after Energy’s public comment period before we received all the documentation we required from Energy before we could move ahead with our comment period.
Meanwhile, Energy awarded contracts to start filling Tunnel 2 with concrete. We made it clear we would not allow concrete to flow until the public had a chance to weigh in.
Public comment or immediate action?
At that point — mid-summer 2018 — we were caught between two opposing forces.
Energy wanted to move forward immediately with concrete – before our comment period had even started. To bolster its position, it released images from Tunnel 2’s interior that showed corrosion in the metal supports at one end of the tunnel.
Opponents wanted public meetings and asked us to deny permission to use concrete.
We insisted on carrying through with a public hearing and a full public comment period. Although, again, we feel strongly that we were looking out for the public’s right to influence Hanford decisions, local Tri-City community leaders sharply criticized us for not allowing the concrete work to begin immediately — a move that would have prevented meaningful public comment.
We prohibited concrete to flow, but we did allow Energy’s contractors to set up equipment so that work could begin as soon as (if and when) we issued our approval.
Priority: prevent another collapse
In the end, we provided two opportunities for public comment — one in the Tri-Cities in late August and one in Seattle in early September — and we allowed the public comment period to run to its full conclusion. Our staff reviewed public comments as they came in, and stayed up into the night after the comment period ended to review the last-minute submissions.
They concluded that, while we agree there were valid concerns about using concrete in the tunnel, those concerns did not outweigh the threat to health and safety should another collapse release radioactive contamination.
The day after the public comment period ended, we allowed work to proceed. And now that work is done.
But the story of the PUREX tunnels hasn’t ended. Next year, we expect to begin the process to determine ultimate disposition of the waste in the tunnels. Potential answers include sawing the concrete into blocks and moving it to the large engineered on-site landfill where most of the rest of Hanford’s contaminated soil and equipment has been placed.