The South Carolina facility leverages its unique history to tackle new challenges.
A few days after Thanksgiving in 1950, the Atomic Energy Commission (AEC) announced that nearly 400 square miles of South Carolina farmland would become the Savannah River Plant, a new AEC facility. The news release heralding the facility’s creation was brief—only one page—but every turn of phrase was carefully crafted. The authors noted that the new facility would be a “production plant” that would “not involve the manufacture of atomic weapons.”
In nearby towns, however, rumors circulated that a “bomb plant” was coming to the area. No sooner had the AEC made its announcement than South Carolinians and the media began to refer to the Savannah River Plant as “the H-bomb factory.”
The nickname stuck, and today locals and journalists alike still refer colloquially to the Savannah River Site (SRS, as the facility is now named) as a “bomb factory”—even though, true to the AEC’s original news release, no nuclear weapons have ever been manufactured there.
Instead, throughout the Cold War, SRS played a crucial role in ensuring the United States’ nuclear security by producing or processing key materials, such as plutonium and tritium, that were used in weapons manufactured elsewhere.
Today, SRS is working closely with Los Alamos National Laboratory as the two facilities restart the United States’ plutonium pit production capability —an endeavor crucial to ensuring the ongoing safety, security, and effectiveness of the nation’s nuclear deterrent.
Unlike other facilities in the nuclear enterprise that are operated by contractors on behalf of the National Nuclear Security Administration (NNSA), Savannah River is managed by a contractor on behalf of the Department of Energy's Office of Environmental Management. In 2025, NNSA will assume primary authority for the site.
Two key materials
Although Savannah River’s recent missions encompass projects ranging from ecological research and environmental remediation to the recovery of highly enriched uranium for use in the manufacturing of new commercial nuclear reactor fuel, the facility was built primarily to produce two materials: plutonium-239 and tritium.
In 1950, the Hanford Site in Washington state was already producing plutonium (for use in nuclear weapon cores) and tritium (which increases a weapon’s explosive power). But in the aftermath of the Soviet Union’s first successful nuclear weapon test in 1949, President Harry Truman felt that the United States needed to augment its nuclear weapons production capability—and fast. The AEC would need to construct a sister facility to Hanford to meet production targets.
After a nationwide search, the AEC settled on a site along the Savannah River, which forms most of the border between South Carolina and Georgia. This site had several advantages. For one thing, the Savannah River would furnish abundant water, which would be necessary to cool the facility’s five reactors and produce heavy water, a more hydrogen-rich liquid that’s key to effective fission chain reactions. Moreover, the site was far enough inland to mitigate the risk of Soviet air attacks and remote enough to ensure secrecy. (To prevent erosion and further bolster security, the Forest Service planted 40,000 pine seedlings per day between 1952 and 1956 on reclaimed farmland on site. In 1968, the Forest Service planted its hundred millionth tree at SRS.)
Savannah River’s first plutonium production reactor, R Reactor, went critical—achieved a sustained nuclear chain reaction—in December 1953. Four other reactors soon followed suit. For nearly four decades, Savannah River used these reactors to produce plutonium-239, the isotope of plutonium that is considered “weapons-grade,” or adequate for use in nuclear weapons. This plutonium was shipped cross-country to the Rocky Flats Plant in Colorado for fabrication into pits. These pits would then be installed in weapons at the Pantex Plant in Texas.
Between 1953 and 1988, Savannah River produced some 36 tons of weapons-grade plutonium, or approximately one-third of all the United States’ plutonium. Savannah River ceased its plutonium production at the end of the Cold War in 1992, the same year that Rocky Flats closed.
While Hanford produced most of the nation’s plutonium, beginning in the mid-1950s, virtually all the United States’ tritium was produced at Savannah River. During the Cold War, Savannah River produced tritium on site by irradiating lithium-aluminum rods, yielding tritium.
Tritium is a radioactive isotope of hydrogen that is a key component of modern nuclear weapons because it increases a weapon’s yield—the amount of energy released after detonation. However, tritium decays to half its original amount in a little over 12 years, which necessitates periodic replenishment of the tritium inside weapons.
Today, Savannah River remains the only facility in the United States to extract, recycle, and purify tritium for use in nuclear weapons. Because its plutonium production reactors have been closed, Savannah River no longer irradiates lithium rods in reactors on site. Instead, rods irradiated in a commercial power reactor at the Tennessee Valley Authority’s Watts Bar Nuclear Plant, located near Spring City, Tennessee, are sent to Savannah River, where the tritium is extracted.
From recovering and recycling the gases in old reservoirs, to loading, certifying, and shipping new reservoirs, tritium processing involves many steps. “Tritium production is something that sounds simple but is actually very complex,” says Bryan Cox, a public affairs officer at Savannah River.
Because the United States’ nuclear weapons require tritium to work, tritium must be processed to exacting standards and on demanding timeframes that ensure the nation’s nuclear arsenal remains amply supplied. As Cox notes, Savannah River has always risen to the challenge. “In 75 years, SRS has never missed a tritium shipment,” he says.
The pit production mission
Cox says that Savannah River’s track record with its tritium mission reflects its workforce’s “production mindset.” In Cox’s view, this mindset is part of the reason that Savannah River is well-suited for its newest mission: the fabrication of plutonium pits. “For this workforce, pit production is something that just makes sense,” Cox says.
In 2018, the Nuclear Weapons Council endorsed the National Nuclear Security Administration’s (NNSA’s) plan for producing new plutonium pits. According to this plan, by 2030—or as soon as possible thereafter—Los Alamos National Laboratory will produce no fewer than 30 pits per year, while Savannah River will produce no fewer than 50 pits per year. Together the two sites will be able to restart the nation’s pit production capacity, which has been dormant since the Rocky Flats Plant closed in 1992.
Los Alamos and Savannah River each bring unique assets to their pit production endeavors. The world’s first plutonium pits were manufactured at Los Alamos in the 1940s as a part of the Manhattan Project, and in the intervening decades, researchers at Los Alamos have gained a comprehensive understanding of plutonium’s properties. (In 2009, NNSA formally recognized Los Alamos’ contributions to plutonium science by designating the Laboratory as the nation’s Plutonium Center of Excellence.)
Although Savannah River doesn’t have Los Alamos’ familiarity with pit production, SRS’s tritium mission means that its workforce is attuned to the demands of a tight production schedule, while its other endeavors have yielded extensive experience producing and handling plutonium. Moreover, Savannah River’s Building 226-F is well-suited for conversion into a pit production facility. Built to be the Mixed Oxide Fuel Fabrication Facility, which would have converted surplus weapons-grade plutonium into fuel for use in commercial nuclear reactors, Building 226-F meets seismic requirements and has support facilities—including office, assembly, and fabrication spaces—that will allow the structure to be redeveloped into the Savannah River Plutonium Processing Facility (SRPPF).
Savannah River and Los Alamos are working closely together as they ramp up their pit production missions. Employees from each site have begun to visit the other for short- and long-term assignments to better conduct training and exchange knowledge.
Savannah River program manager Leo Thompson recently accepted an assignment at Los Alamos. At the Laboratory, he will help coordinate the two pit production organizations, with the goal of finding opportunities for Savannah River’s workforce to learn from Los Alamos’ workforce. “Savannah River has experience in plutonium production and handling, but we don’t have experience in pit production,” Thompson says. “To help us with our pit production mission at SRS, we’re really counting on the experience that Los Alamos has.”
Thompson says that Savannah River and Los Alamos are collaborating in three key ways. The first is in completing SRPPF’s design, which will be based on the processes and equipment used at Los Alamos.
The second is through the Knowledge Transfer program, in which Savannah River personnel accept two-year assignments to plutonium pit production-related roles at Los Alamos. “After two years, they won’t be experts in pit production,” Thompson says. “But they’ll be able to take knowledge back to Savannah River and increase our collective knowledge of what we need to do.”
Third, the Mutual Support program sends Savannah River personnel to visit Los Alamos either in-person or virtually for short-term assignments to learn about topics including pit production support systems, training, equipment requirements, safety, and waste management. Meanwhile, Los Alamos will benefit from the SRS workforce’s experience with processes such as maintenance engineering and a 24/7 production schedule, which the Laboratory adopted for its pit production in February 2022. Other areas of collaboration include the creation of software to facilitate pit production at both facilities, the completion of Los Alamos’ Site-Wide Environmental Impact Statement, and the development of consistent public engagement practices at both sites.
Although Savannah River will continue to work with Los Alamos to provide materials that ensure the nation’s nuclear security, there are still no plans to turn the site into the “H-bomb factory” that many South Carolinians anticipated seven decades ago. Instead, an ever-closer collaboration between Savannah River and Los Alamos will help the two organizations identify what Thompson calls “enterprise-wide solutions to enterprise-wide challenges.”
Both sites are impacted by issues such as the competitive job market. So what can organizations do together to address these things, to make pit production a more attractive opportunity for young people entering the job market?” Thompson says. “Instead of a one-off collaboration here and there, both organizations are aligned and working together on dealing with these larger challenges. To establish the capacity to produce at least 80 pits per year will require ongoing collaboration between Savannah River and Los Alamos in the long term.” ★