RICHLAND, Wash. – EM Richland Operations Office (RL) and contractor CH2M HILL Plateau Remediation Company (CHPRC) have begun filling the first of three aging underground structures on the Hanford Site with engineered grout in accordance with engineering recommendations.
The interim measure will mitigate the risk of collapse and the potential for contamination spread until a remedy to remove, treat, and dispose of the material in the structures is implemented.
The three structures, located near the former Plutonium Finishing Plant on Hanford’s Central Plateau, received liquid waste during Hanford’s plutonium production operations and contain residual radioactive and chemical contamination. Recent evaluations determined the structures are at risk of age-related failure.
“This is a major step forward in reducing risk at the Hanford Site,” said Al Farabee, Hanford’s senior technical advisor for the project. “Filling these structures with engineered grout will further protect workers and the environment, while not precluding future remedial actions or final closure decisions.”
Grout has been used to safely stabilize other structures at Hanford, including the Plutonium Uranium Extraction (PUREX) Plant waste storage tunnel that partially collapsed in 2017 and an adjacent waste storage tunnel in 2019.
This animation shows the grout delivery system being used to stabilize the three structures. The system pumps the engineered grout from trucks through more than 1,500 feet of pipe to the underground structures. The system was successfully tested using a full-scale mock-up last summer.
“I’m proud of the safe and steady progress our team has made on the stabilization project during obviously challenging circumstances last spring and summer,” said Delise Savior, CHPRC project manager. “We look forward to continuing to work collaboratively with the Department of Energy and regulators to safely complete the project as part of ongoing risk-reduction activities on Hanford’s Central Plateau.”
Stabilization of all three structures is expected to be completed by the end of the year.