Two companies are working together to extract rare isotopes for cancer treatment research from nuclear waste at the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL) in Tennessee.
The project was unveiled in late November by Isotek Systems, a DOE contractor that oversees management of uranium-233 stored at ORNL, and TerraPower, a company co-founded by Microsoft’s Bill Gates with the aim of developing a more affordable, secure, and environmentally friendly form of nuclear energy.
The Department of Energy and company executives said the project will help expedite the disposal of uranium-233 now held at ORNL, save taxpayers about $90 million as the highly enriched fissile material is removed from storage, and increase the number of cancer treatment doses that could eventually be available each year.
Isotek is removing thorium-229 from the uranium-233 at the lab and selling it to TerraPower. The thorium will be shipped to a TerraPower laboratory in Everett, Wash., north of Seattle. There, TerraPower plans to extract actinium-225 from the material for use in cancer treatment research.
“It’s an exciting thing for us to clean up legacy material and save a rare isotope for potential cancer treatment,” Isotek President Jim Bolon said at the project rollout.
This is a public-private partnership that also involves DOE and its Oak Ridge Office of Environmental Management. Extraction of the thorium began this fall. Roughly 100 shipments using shielded containers are expected from Oak Ridge to the TerraPower laboratory in Everett.
TerraPower, based in Bellevue, Wash., received its first milligram-sized batch of thorium in November, according to Jeff Latkowski, senior vice president of innovation.
Federal officials and company executives said alpha-emitting isotopes such as actinium-225 could be used to treat prostate, acute myeloid leukemia, colorectal, and other cancers. TerraPower has been studying what it calls targeted alpha therapy since 2013, and last month’s announcement was the culmination of about five years of work, according to President and CEO Chris Levesque.
A small amount of actinium could be attached to a targeting molecule that would find a specific type of cancer. The radiation from the actinium could kill the cancer cells without damaging the surrounding healthy cells.
“This is a much more targeted approach,” Levesque said. Trials of actinium in other countries have shown promising results, he added, but more research is needed in the United States, along with approval by the U.S. Food and Drug Administration.
TerraPower hopes to begin providing actinium for research and development to biotech firms and pharmaceutical companies in the second half of 2020. The company expects to purchase about 40 to 45 grams of the thorium during a five-year period. That would be enough to produce about 100 times more actinium-based cancer treatment doses per year than the 4,000 doses that are currently available worldwide.
The Energy Department, Isotek, and TerraPower celebrated their public-private partnership by announcing the project in Oak Ridge on Friday, Nov. 22.
Levesque said the amount that TerraPower will pay Isotek for the thorium is confidential, but it is in the range of millions of dollars. Energy Department officials and company executives said TerraPower is paying a reasonable price for materials that don’t currently have a market.
TerraPower and Isotek reached an agreement about a year ago, and their partnership could last about five years.
To enable the initiative, DOE agreed in October 2017 to allow Isotek to use and modify current facilities to extract thorium for TerraPower.
Isotek has since 2003 been responsible for overseeing the uranium-233 inventory at ORNL, and preparing for its removal. The company’s uranium disposition contract, which is currently valued at $557 million through December 2024, is managed by the Oak Ridge Office of Environmental Management.
Isotek’s task is to remove the uranium-233 stored in ORNL’s Building 3019, which was built in the 1940s. It’s the top-priority cleanup project at the lab. The Energy Department says Building 3019 is the oldest operating nuclear facility in the world, and storing the uranium at the lab increases security costs and creates nuclear safety issues.
Uranium-233 is a radioactive isotope of uranium that does not exist in nature, but it can be produced by bombarding thorium-232 with neutrons. The material was generated from DOE-related missions at various sites across the country.
About half of the material at ORNL has been transferred and dispositioned. The remaining waste must be processed and downblended ahead of disposal.
More than 500 canisters of uranium-233 remain, mostly as uranium oxide but also in metal and ceramic monoliths. There are also sodium fluoride traps from the Molten Salt Reactor Experiment at ORNL, where uranium-233 fluoride salt and other fuels were tested.
Isotek will use the money from the sale of the thorium-229 to pay for part of the uranium-233 disposal. That allows downblending operations to begin a year ahead of schedule and saves about $90 million through direct private funding and reduced costs as the material is removed from storage, according to DOE.
The private funding of part of the cleanup project means DOE now expects to complete all uranium-233 processing operations in 2025. The downblending operations, which result in a low-level grout waste, will occur at Building 2026, across the street from Building 3019 at ORNL. The solid concrete-like grout will be shipped for disposal to a DOE-designated site.
