ORNL isotopes: 80 years, infinite possibilities

Historic black-and-white photo of four men gathered around a table in an industrial laboratory, with equipment in the background.

On Aug. 2, 1946, as newspaper reporters crowded the stage, scientists at Clinton Laboratories in Oak Ridge, Tennessee, made a ceremony of the very first official shipment of a reactor-created radioisotope. Carbon-14, a medical isotope, was sent to the Barnard Free Skin and Cancer Hospital in St. Louis, Missouri, from what would become the Department of Energy’s Oak Ridge National Laboratory in 1948.

In the background loomed the X-10 Graphite Reactor. Just three years before, the reactor had made history as part of the Manhattan Project, generating a self-sustaining nuclear reaction and ushering in a new age for nuclear. It would soon begin producing the necessary plutonium needed to develop atomic weapons that brought about the end of World War II.

With wartime at an end, American scientists looked for a way to repurpose the power of atomic energy for peacetime. They found it in the production of radioisotopes, unstable variants of elements that give off radiation as they decay.

Orange and blue particles clustered together, with one orange particle separated to the left.

Radioisotopes’ uses extended to medicine, industry, scientific research — and the unknown. Scientists already knew isotopes were valuable commodities; physicists at various institutes had an informal network to exchange these fission “byproducts” for research purposes. But the Graphite Reactor supplied a multitude of new and exciting radioisotopes to eager civilian institutions.

A few months before that first C-14 shipment, Science magazine had published a “catalog” of radioisotopes available from Oak Ridge. Right after that official August 2 kick-off, the lab began sending out a backlog of isotope orders, even as more orders poured in. Oak Ridge made more than 1,000 shipments of 60 different isotopes during that first year. Over the next four years, shipments swelled to 20,000.

As demand for radioisotopes continued to grow, so did Oak Ridge's capabilities. The Graphite Reactor became the world’s leading source for radioisotopes — including for the lab’s own researchers, who used them to enable discoveries in biology, nuclear energy, radiation safety and other fields.

It also established Oak Ridge’s isotope expertise. In special facilities at the lab, experts innovated processes for producing, separating and packaging the rare and coveted materials. Some prolific customers even located their own facilities in East Tennessee to get closer access to the isotopes they needed.

Nuclear reactor viewed from above, glowing bright blue amid metal walkways and equipment.

The excitement over isotopes led to the construction of dedicated hot-cell facilities such as the Radiochemical Engineering Development Center, where radioisotopes are still processed and produced today.

ORNL's High Flux Isotope Reactor, a powerful research tool that has the world’s most intense neutron flow, doubles as an excellent production plant for exotic, short-lived isotopes such berkelium, californium, einsteinium and fermium — some of which aren’t produced anywhere else in the world.

Meanwhile, the nearby plant in Oak Ridge, where Y-12 National Security Complex currently sits, was equipped with enormous calutrons, magnetic machines used during the war to separate isotopes of uranium. After the war, the calutrons were repurposed to separate other stable isotopes. The calutrons, which required vast electricity and manpower, produced enriched stable and actinide isotopes for medical, research, commercial and national security applications.

Dedicated workers at the calutrons determined the neutron cross-section of all the isotopes of every element, information that propelled the design of new reactors. The Isotope Enrichment Group separated every element that had more than one isotope — and then saved them for not-yet-discovered uses. Though the last calutron shut down in 1998, this group’s foresight built the national stable isotope stockpile ORNL now stewards. Today’s researchers are still finding uses for the rare and diverse isotopes dispensed from the painstakingly preserved stable isotopes in that stockpile.

Today, ORNL can provide more than 250 isotopes — both stable, which do not decay, and radioisotopes, which are radioactive and decay over time. In a typical year, the lab fills orders of about 80 different isotopes through the DOE Office of Isotope R&D and Production. The customers are medical facilities, research institutions and industry partners that use them to help treat cancer, diagnosis disease, discover new elements, find oil and minerals, test the structural integrity of seams and welds, learn the chemical composition of materials, power nuclear batteries and more.

One ORNL-produced isotope, plutonoium-238, has provided energy to spacecraft on Mars and will be on board NASA’s upcoming Dragonfly mission to Saturn’s moon Titan.

Researchers are continuously finding new and better ways to produce isotopes, at the same time they’re finding novel applications for them — and even finding new elements. In 2010, the isotope berkelium-249, produced at ORNL, enabled U.S. and Russian scientists to discover element 117, tennessine — the only missing element on Row 7 of the periodic table. Its name recognizes Tennessee’s contributions to its discovery, including ORNL’s unique production capabilities.

ORNL's isotopes touch nearly every part of modern life:

Californium-252 is used worldwide to start up nuclear reactors, and ORNL is its only producer in the western world.
Actinium-225 has been heralded as the next cancer breakthrough, attacking cancer cells with the precision of a guided missile. Teams at ORNL work around the clock to increase the availability of this crucial medical isotope for patients worldwide.
Nickel-63 is in machines in nearly every airport, detecting explosives. ORNL produces this security-supplying isotope for the entire nation.
Promethium-147, discovered at ORNL in 1945, shows potential for powerful and efficient nuclear batteries. ORNL experts have developed methods for retrieving it from byproducts left over from plutonium-238 production and purifying it for new uses.

Stable Isotope Production and Research Center (SIPRC) at Oak Ridge National Laboratory is a new DOE facility, illustration

The list goes on, and demand for isotopes keeps increasing, with no signs of slowing. To help meet the nation’s needs, DOE is building two new nuclear facilities at ORNL: the U.S. Stable Isotope Production and Research Center, which will employ next-generation technology to enrich multiple stable isotopes for medical, industrial and national security uses, and the Radioisotope Processing Facility, which will transform U.S. capability to provide highly sought radioisotopes for multiple uses — now and in the future.

ORNL’s past pushed the lab to its position as a world leader in isotope R&D and production. Its inventive science has found new uses for isotopes and better ways to make them. Its future promises more. More isotopes. More applications. More world-changing science. In the next 80 years: infinite possibilities.

UT-Battelle manages ORNL for DOE’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science works to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.