A former 310-square-mile-site of plutonium and tritium production in Aiken, South Carolina, that focuses on environmental cleanup has won the U.S. Department of Energy’s Sustainability Award in the “Innovative Approach to Sustainability” category.
The Savannah River Site, which produced plutonium (radioactive chemical element) and tritium (radioactive material) for nuclear weapons from the early 1950s through the end of the Cold War, was honored for using plants to clean up a contaminated environment, a news release said.
Since 2001, 62 acres of pine trees at the site were used “like a forest of tall hydraulic pumps,” in that they drew up “irrigated water containing tritium pumped from a nearby holding pond and harmlessly release it into the atmosphere through photosynthesis,” the release said.
“Your efforts and commitment to sustainability have been essential in ensuring DOE's continued success as a federal leader in sustainability,” said Scott Whiteford, director of the DOE Office of Asset Management, in the release.
At the Savannah River Site, approximately 190 million gallons of water that had nearly 7,000 curies of tritium were irrigated, preventing “contaminated groundwater from discharging into a nearby stream.”
“Simply put, we reroute the contaminated water from moving toward the site boundary and, instead, use the forces of nature to safely transform and eliminate it from the site,” said Jeff Thibault, an engineer with environmental management contractor Savannah River Nuclear Solutions, in the release.
The project’s cost has been approximately $12 million.
“Traditional remediation costs associated with this level of tritium removal using ‘pump, treat and reinject’ equipment would have cost close to $180 million over the last 20 years,” Philip Prater, DOE-Savannah River senior physical scientist, said in the release.
The project doesn’t need “round-the-clock operations” because the contaminated groundwater flows naturally to the surface and collects in a small holding pond.
“Only limited pumping is needed in support of the irrigation system, as the trees naturally provide for water uptake and evapotranspiration to the atmosphere,” Kevin Boerstler, Savannah River Nuclear Solutions Area Completion Projects subject matter expert, said in the release.
The Savannah River Site’s sustainable cleanup approach doesn’t create “large volumes of waste,” Prater said in the release. “Further, it’s environmentally friendly, as phytoremediation provides for an astounding carbon sequestration of 192 tons annually, an estimated offset equivalent to the use of 37 cars each year.”
Prater said in the release that mechanical evaporator systems are about 25% effective compared to trees.
“Public concerns about managing contaminated water at SRS are understandable,” Thibault said in the release. “However, test results validate that the level of tritium found within the irrigation area produces a radiation dose so low as to be insignificant. The fact is optimal water levels are being maintained in the pond. The evaporated tritium becomes virtually immeasurable beyond the irrigated section of forest, much less at the site boundary.”
The Oak Ridge Office of Environmental Management received a Sustainability Award honorable mention in the “Strategic Partnerships for Sustainability” category, the release said.
One of three original sites in the Manhattan Project (nuclear weapons research and development during World War II), the Oak Ridge site is in eastern Tennessee.
“Our community is extremely proud of the ongoing public and private partnerships by OREM and UCOR [United Cleanup Oak Ridge] that are transforming the Oak Ridge Reservation and our region while advancing sustainability and natural resource management in our area,” said Community Reuse Organization of East Tennessee President and CEO Teresa Frady in the release. “Together we’ve proven that with planning and collaboration, cleanup can enable both economic revitalization and conservation goals.”
