Workers have begun stabilizing a partially collapsed waste storage tunnel on the Hanford Site.
Office of Environmental Management
August 31, 2017
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Workers insert probes through existing risers on top of PUREX Tunnel 1 to check conditions inside of the collapsed tunnel. Visual and radiological conditions inside the tunnel will support grout placement.
RICHLAND, Wash. – Workers have begun stabilizing a partially collapsed waste storage tunnel on the Hanford Site.
EM’s Richland Operations Office (RL) and contractor CH2M HILL Plateau Remediation Company (CH2M) intend to add grout to Tunnel 1 adjacent to the Plutonium Uranium Extraction (PUREX) Plant in coming weeks. The tunnel partially collapsed in May 2017.
The grout will improve tunnel stability, provide additional radiological protection, and increase durability while not precluding future remedial actions or final closure decisions. RL has used grout to fill parts of other buildings and facilities successfully in the past. It can be effectively implemented at a reasonable cost.
Trials are underway to ensure the grout formulation selected for placement in Tunnel 1 is engineered appropriately for flowability, strength, and cure time.
Workers are using existing ports to check conditions inside the tunnel. Their analysis will support safe and compliant grout placement.
Trials of engineered grout with different properties are underway. CH2M recently awarded a subcontract to Richland-based Intermech, Inc., to place the grout. CH2M and Intermech will conduct mockups to train workers to lay the material safely.
Approximately 6,000 cubic yards of grout are needed to fill the 358-foot-long tunnel currently holding eight railcars containing legacy radioactive plutonium processing equipment. Workers are set to finish placing grout by the end of December.