International Collaboration Enhances Wastewater Treatment at Oak Ridge

Source: EM Update | Vol. 13, Issue 49; Contributor: Ben Rivera | December 21, 2021

A collaboration between EM and the United Kingdom is helping operations continue at a key wastewater treatment facility at Oak Ridge National Laboratory (ORNL), ensuring important research and environmental cleanup missions are not disrupted.

Oak Ridge Office of Environmental Management (OREM) cleanup contractor UCOR partnered with the National Nuclear Laboratory (NNL) in the U.K. to study new technologies and methods to remove cesium and strontium from wastewater at the Process Waste Treatment Complex (PWTC) at ORNL.

Working with their U.K. peers, UCOR employees benchmarked PWTC operations against those at the Site Ion-Exchange Plant at the Sellafield facility, a nuclear reprocessing plant that has operated in the U.K. for more than 40 years. The technical information and lessons exchanged have been significant for both parties.

“This is just the latest great example of how important engagement is with our international partners to move the cleanup mission forward,” said Joceline Nahigian, director of EM’s Office of Intergovernmental and Stakeholder Programs. “This most recent collaboration is well timed as we move toward renewing the agreement allowing for continued engagement with the U.K. team to enable cleanup activities.”

After UCOR implemented the recommendations from the collaboration, the PWTC has operated consistently for periods of more than 90 days compared with just a few days at a time before the changes were made.

“Thanks to the input from the U.K. team, we have been able to triple our operating time while achieving more consistent, effluent numbers,” UCOR System Engineer Jason Jeansonne said. “This improvement in performance has eliminated previous day-to-day operating concerns and allowed us to focus attention on permanent improvements in the ion-exchange approach.”

In addition to the operational benefits at Oak Ridge, Sellafield Ltd. and NNL also gained useful insight into the challenges being faced and the information gleaned will be useful in helping to identify ion-exchange resins that could potentially be used to support Sellafield Ltd. cleanup operations in the future. Discussions in this area are ongoing as testing and operations at Oak Ridge continue to progress. Sellafield Ltd. is the company tasked with cleaning up the Sellafield site.

Approximately 90 million gallons of wastewater are generated by research and cleanup operations at ORNL annually. That water is collected and treated in the PWTC system.

Known as Liquid and Gaseous Waste Operations, the overarching infrastructure consists of numerous interconnected facilities that support crucial waste treatment activities for EM and the DOE Office of Science. UCOR recently supported EM’s plan to reduce the cost of treating wastewater by consolidating capabilities into a single facility.

Due to its age and deteriorated condition, Building 3544, the PWTC facility that treated radiological waste, presented one of the largest risks. The building had served as a radiological wastewater treatment facility for more than four decades. It housed an older zeolite treatment system designed to remove cesium and strontium from wastewater. Zeolite is a naturally-occurring mineral formed from volcanic ash which can strip contaminants from wastewater.

OREM installed a new zeolite treatment system in Building 3608 that consolidates treatment of both radiological and non-radiological waste into one facility rather than two. The consolidation allowed EM and UCOR to shut down Building 3544 and prepare it for decommissioning and demolition.