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Independent Panel Recommends Stabilizing Second Hanford Tunnel With Grout

An independent panel of experts recommended DOE stabilize a second waste storage tunnel on the Hanford Site using engineered grout.

Office of Environmental Management

December 12, 2017
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Hanford’s Plutonium Uranium Extraction Plant includes two adjacent waste storage tunnels filled with rail cars containing radiologically contaminated plutonium processing equipment. Tunnel 2 is nearly 1,700 feet long, considerably longer than Tunnel 1.
Hanford’s Plutonium Uranium Extraction Plant includes two adjacent waste storage tunnels filled with rail cars containing radiologically contaminated plutonium processing equipment. Tunnel 2 is nearly 1,700 feet long, considerably longer than Tunnel 1.

RICHLAND, Wash. – An independent panel of experts recommended DOE stabilize a second waste storage tunnel on the Hanford Site using engineered grout.

   The panel assessed several stabilization options for safety, ease, and cost, and whether they would allow for disposition of the equipment in the Plutonium Uranium Extraction Plant (PUREX) Tunnel 2.

   In their report, the panelists noted that grout stabilization provides maximum protection of workers, the public, and the environment while not precluding future options for disposition. They also acknowledged DOE’s use of grout across the complex to successfully immobilize contamination. 

   “DOE is committed to the safety of its workforce, the public, and the environment. Grouting safely and efficiently reduces near-term risk by providing interim stabilization while DOE and the Washington State Department of Ecology evaluate future closure options,” said Doug Shoop, manager of EM’s Richland Operations Office

The partial collapse of Tunnel 1 at the Plutonium Uranium Extraction Plant (PUREX) did not result in worker injuries or release of radioactivity, but a tarp was placed as added precaution until the tunnel could be stabilized with engineered grout.
The partial collapse of Tunnel 1 at the Plutonium Uranium Extraction Plant (PUREX) did not result in worker injuries or release of radioactivity, but a tarp was placed as added precaution until the tunnel could be stabilized with engineered grout.
Tunnel 2 at the Plutonium Uranium Extraction Plant (PUREX) was constructed of steel and concrete and contains 28 rail cars containing radiologically contaminated plutonium processing equipment.
Tunnel 2 at the Plutonium Uranium Extraction Plant (PUREX) was constructed of steel and concrete and contains 28 rail cars containing radiologically contaminated plutonium processing equipment.

   In mid-November, DOE safely and successfully finished placing engineered grout to stabilize PUREX Tunnel 1. Tunnel 2 was under continual surveillance during that project.  

   Tunnel 2 is nearly 1,700 feet in length — considerably larger than Tunnel 1. Tunnel 2 is constructed of steel and concrete, and contains 28 rail cars with radiologically contaminated plutonium processing equipment. It was used between 1964 and 1996.

   Grout placement in Tunnel 2 is expected to begin during this fiscal year ending Sept. 30, 2018, allowing time to incorporate lessons learned from the Tunnel 1 project, development of work controls and design, and consideration of seasonal conditions for grout placement.

   “I want to thank those who provided their input on this important recovery action,” Shoop said. “It is vital to have considered every option.”

   The panel’s report is available on this page, which features information about the PUREX tunnels. Read an EM Update interview in a separate newsletter entry below on EM's Chief Engineer John Marra, who chairs the panel.