By George Lobsenz
Saying it would save more than $1 billion compared to “traditional” decommissioning methods, the Energy Department said Tuesday it was moving ahead with a $297.5 million project to close in place “for centuries” two contaminated weapons production reactors at its Savannah River Site in South Carolina–a first for DoE’s nuclear weapons complex.
While DoE typically removes contaminated piping and vessels from nuclear facilities during decommissioning to prevent long-term seepage of radioactive materials into the environment, the department said a significant amount of equipment will be entombed in Savannah River’s P and R reactors.
In a press release, the department said below-ground equipment and the reactor vessel will remain in the reactor buildings, which then will be partially filled up with a cement-like grout that is specially formulated to lock contaminants in place.
“The grout will be pumped into each structure up to ground level, filling vessels, voids and spaces in an effort to fully entomb the facility and its components for centuries,” DoE said in the press release.
The department indicated that some aspects of the closure project had not been resolved and might differ among the reactors, depending on circumstances.
“Final closure details are determined at the time each individual reactor complex is closed,” DoE said, adding: “The closure method is being modeled at the…P Reactor, the first of the five Savannah River Site reactors to be closed via this process of in-situ decommissioning.”
DoE already has awarded some contracts for work on the P Reactor, with officials saying efforts there began last year.
The department also plans to close in place the C, K and L reactors at Savannah River after current operations at some parts of those facilities–such as interim waste storage- -are completed.
The reactors, built during the Cold War and operated for decades to produce plutonium, tritium and other special materials for the nation’s nuclear weapons, were closed in the late 1980s and early 1990s due to serious safety issues.
As with many other DoE weapons facilities, the reactors are massive, hardened structures with thick walls, making them hard to demolish, especially with the high levels of radioactivity inside.
However, leaving such buildings in place is politically sensitive in many states hosting DoE sites. State officials in Washington are still discussing with DoE what to do with shuttered weapons facilities at the department’s Hanford site.
The Savannah River reactor closure project, which is being carried out under the Superfund cleanup program, was approved by the U.S. Environmental Protection Agency’s Region 4 office and the South Carolina Department of Health and Environmental Control (SCDHEC), which oversee nuclear and environmental safety at Savannah River.
“The collaboration of DoE, SCDHEC, and EPA to work with multiple stakeholders and the public has resulted in this precedent-setting decision,” Robert Pope, federal facilities agreement manager for EPA Region 4. “All three agencies have worked hard to engage the community and make this the first final cleanup of a Cold War-era reactor under [Superfund]. EPA appreciates all the effort put forth by the community, SCDHEC and DoE to lead the nation in cleanup.”
While DoE is considering closing in place contaminated facilities at other department sites, the Savannah River reactors are the first buildings with significant levels of radioactivity to be approved for such on-site disposal. The department is burying large amounts of low-level waste at several sites, including Savannah River.
However, in an interview with sister publication The Energy Daily, Pope acknowledged that some of the equipment to be left in Savannah River’s reactors–such as the steel vessels that held the reactor cores–have relatively high radioactivity levels and will remain dangerous for thousands of years. He indicated that some contaminated equipment was more radioactive than low-level waste, but declined to say whether it would be classified as high-level waste.
Overall, though, Pope said safety analyses conducted under EPA’s Superfund authority showed that fully dismantling the underground reactors would pose unacceptable health risks to workers due to high radioactive levels. He also said the analyses showed that contamination would not seep out of the reactors for thousands of years, and even then would not dangerously pollute groundwater.
However, Pope said neither DoE nor EPA set a formal “performance standard” for the project–meaning a guarantee that groundwater contamination would not exceed certain levels over a defined period of time. Such standards are typical for most nuclear waste disposal projects.
The threat of groundwater contamination is particularly clear at the Savannah River reactors because they are built mostly underground, and the water table at the site is relatively close to the surface. Pope said the water table at Savannah River was at the base of the R reactor, meaning contaminated seepage would not have to travel far underground to get to groundwater.
In a somewhat unusual procedure for a sensitive nuclear cleanup project, neither DoE nor EPA was able to make available Tuesday the formal safety analyses done on the reactor closure project.
But Pope said the Superfund record of decision on the reactor project was available at DoE libraries in South Carolina, and he said key data from safety analyses was shared with communities in South Carolina at three public hearings over the past year or so. Pope also said Savannah River’s community advisory board had been briefed numerous times on the project.
Pope said the analyses were not reviewed by the Nuclear Regulatory Commission, though that agency is often consulted by DoE on high-profile nuclear cleanup projects.
The reactor closure project is being accelerated due to additional money provided for Savannah River cleanup by the American Recovery and Reinvestment Act.
In addition to extra money, DoE officials said its cleanup contractor, Savannah River Nuclear Solutions, had produced “a solid performance baseline” for the project, resolving questions that had been raised last year about its planning.