For decades, some of the material stored at Oak Ridge National Laboratory represented a nuclear cleanup problem. Today, part of that same legacy is becoming increasingly valuable to nuclear medicine.
The U.S. Department of Energy's Oak Ridge Office of Environmental Management and contractor Isotek Systems have officially opened a new analytical laboratory at ORNL designed to accelerate processing of the site's uranium-233 inventory. The facility, located in Building 2026, has two closely connected purposes: move the government's U-233 cleanup program forward and accelerate the delivery of material that ultimately supports production of actinium-225 for cancer research and potential treatments.
The Ac-225 connection isn't new. Oak Ridge has been involved in supplying the isotope for decades, and the government's U-233 inventory has already become an important source of thorium-229 used in the production chain. What is new is the infrastructure being added to move that material through the system more efficiently.
That makes the new laboratory more than another Ac-225 capacity story. It illustrates something bigger happening at the intersection of America's nuclear legacy and its rapidly expanding nuclear medicine industry: materials once viewed primarily as liabilities can sometimes become strategic medical assets.
The story begins with uranium-233, a fissile material produced decades ago as part of U.S. nuclear research and development programs. DOE has been working to disposition the inventory at Oak Ridge, making it fundamentally an environmental-management and nuclear-cleanup responsibility. But radioactive decay created something unusually valuable inside that inventory.
U-233 contains thorium-229, which can ultimately provide material used in the production of Ac-225. Oak Ridge has been recovering Th-229 from the inventory through the Thorium Express Project, and in 2025 Isotek reported that it had extracted more than 15 grams of the rare isotope for shipment to TerraPower Isotopes.
That creates an unusual economic and scientific loop. The federal government needs to process and disposition legacy nuclear material, while the nuclear medicine industry needs an isotope embedded within that material's decay chain. And instead of those being entirely separate problems, the same infrastructure can help address both.
The new analytical laboratory matters because processing radioactive material isn't simply a matter of removing it from storage and shipping it elsewhere. Characterization, analysis and quality verification are essential parts of the process.
By bringing additional analytical capability into Building 2026, DOE and Isotek can accelerate work on the U-233 inventory and support faster movement of valuable isotope material through the program. The August 21 announcement specifically connects the new laboratory with both high-priority U-233 cleanup and faster delivery of Ac-225 to facilities involved in cancer research and potential treatment.
That makes the facility an interesting piece of nuclear medicine infrastructure even though it was created within an environmental-management program. The United States didn't originally produce its U-233 inventory because it expected targeted alpha therapy to emerge decades later. Yet material generated during an earlier era of nuclear development is now feeding an entirely different industry.
That is difficult infrastructure to recreate.
The nuclear medicine industry is pursuing numerous ways to increase isotope production. New accelerators can be built. Radium-226 targets can be manufactured and recycled. Cyclotron and reactor routes can be expanded. Entire new production facilities are under construction.
But legacy U-233 is different because the starting material already exists. And the supply is finite.
That gives the Oak Ridge inventory characteristics that differ from a conventional manufacturing asset. The opportunity isn't simply to build another machine and produce more feedstock. It is to extract as much useful medical value as possible from material that the federal government already possesses and ultimately intends to disposition.
The importance of that resource has become increasingly apparent. Isotek's Thorium Express Project has already dramatically increased the amount of Th-229 available, with more than 15 grams recovered by May 2025 for use by TerraPower Isotopes. The new laboratory should help that process move faster.
It is important not to portray the project as though Oak Ridge suddenly discovered Ac-225. ORNL's history with the isotope stretches back decades. The laboratory sent its first shipment of Ac-225 to the National Institutes of Health in 1997 and has long operated specialized radiochemical processing capabilities supporting medical isotope production.
ORNL also established important regulatory infrastructure years before the current wave of commercial investment. In 2021, the FDA acknowledged receipt of ORNL's Drug Master File for Ac-225 nitrate, allowing pharmaceutical developers to reference the file in regulatory applications involving the isotope.
What has changed is the scale of interest surrounding targeted alpha therapy. The pharmaceutical industry is now investing heavily in alpha-emitting radiopharmaceuticals, and the infrastructure needed to support those programs is expanding with it. That has transformed resources that were once largely the domain of national laboratories and specialized researchers into strategically important inputs for a potential commercial drug industry.
Oak Ridge suddenly finds itself sitting at the intersection of both eras.
There is a broader lesson in the project. The nuclear industry frequently discusses legacy materials in terms of cleanup, disposal and long-term stewardship. Those responsibilities are real, and much of America's historical nuclear inventory ultimately does need to be stabilized or disposed of.
But nuclear materials can behave differently from conventional industrial waste. What is unwanted for one application can contain isotopes that are extraordinarily difficult to obtain for another.
Oak Ridge has demonstrated that principle elsewhere as well. ORNL continues to operate a broad isotope program spanning nuclear medicine, industry, research and national-security applications, including isotopes for which domestic or Western supply is extremely limited. And the U-233 program may be one of the clearest examples because the contrast is so striking: the same inventory can simultaneously represent a federal cleanup obligation and a source of material supporting advanced cancer therapeutics.
The new Building 2026 laboratory is not, by itself, going to solve the isotope supply challenge. Nor is the underlying U-233-to-Th-229 pathway new.
Its significance is what it says about the infrastructure developing around nuclear medicine. The radiopharmaceutical industry's future won't be built exclusively through new factories, accelerators and reactors. Some of its most valuable resources are emerging from infrastructure and materials created for entirely different purposes decades ago.
Oak Ridge is particularly well positioned for that convergence. The laboratory's history stretches across nuclear reactors, isotope science, radiochemistry, national security and environmental cleanup. Increasingly, those capabilities are also becoming relevant to commercial medicine.
The United States spent much of the twentieth century building an enormous nuclear research and production complex. The twenty-first century is beginning to find new uses for pieces of that inheritance.
In Oak Ridge, one of those uses is particularly compelling: turning a nuclear cleanup problem into part of the supply chain for cancer-fighting medicine.
