Around the world, scientists are rethinking how to manage used nuclear fuel - turning a challenge often viewed as waste into an opportunity for innovation, efficiency and energy security.
At the Department of Energy's Oak Ridge National Laboratory, radiochemical engineer Katie Johnson is at the forefront of nuclear fuel cycle research. Her research in the Fuel Cycle Chemical Technology Group centers on separating and recovering valuable materials from used fuel, work that could reduce waste, extend resources and strengthen the nation's energy future. In this Q&A, Johnson shares what it means to close the nuclear fuel cycle, why recycling matters and how her research is advancing the field.
Q: What does it mean to "close" the nuclear fuel cycle?
A: Right now, the nuclear industry operates in an open fuel cycle, meaning there are no mechanisms for recycling used nuclear fuel or "waste" after it has left a nuclear reactor. A closed fuel cycle would mean that our nuclear fuel management strategy would incorporate recycling processes to reduce the amount of waste, to reuse unburned fuel material, and to recover other valuable fission products for other applications. A closed fuel cycle would reduce the space needed to dispose of and store nuclear fuel.
Q: Why is reusing fuel important for the future of nuclear energy?
A: Bringing new nuclear energy to the grid will require us to adapt fuel recycling methods that reduces our reliance on uranium imports. Recycling and reusing fuel extend the life of nuclear resources by maximizing the energy extracted from uranium ore. In turn, we lessen our reliance on uranium mining while also meeting the growing energy demand necessary to secure our nation's energy independence.
Q: What technologies make fuel recycling possible?
A: There are two main recycling technologies for used fuel recycling, which aim to remove the fission products. One approach, called aqueous dissolution or PUREX, dissolves used nuclear fuel in acid so scientists can separate reusable materials. Another approach, pyrochemical processing, uses high-temperature molten salts and leverages electrochemistry for fuel purification. ORNL and other national labs are leading significant research into the development of robust materials and sensor technologies that support safe, automated handling that may be required.
Q: How does your research support a closed fuel cycle?
A: My research focuses on the development of separations technologies for capturing radionuclides - radioactive isotopes produced during fuel recycling operations. Recovering and disposing radionuclides is essential to maintaining regulatory compliance and ensuring environmental protection.
One of the ways we're doing this is through developing solid sorbents for radioiodine capture at ORNL's Iodine Off-gas Testing and Abatement (IOTA) Laboratory. Sorbents are materials that remove unwanted contaminants, typically as a liquid or gas, through either adsorption or absorption. By studying the chemistry and materials science of sorbents, we identify how to effectively remove these contaminants ensure they are managed safely and efficiently.
Q: What challenges still need to be solved to make this happen?
A: There are a few hurdles to closing the nuclear fuel cycle, with radionuclide management and workforce development as key priorities.
While used fuel management has long been handled by the public sector, private companies are increasingly interested in fuel recycling, and they're seeking to be disruptive and innovative. Both private and public entities need to be able to choose from a range of options when it comes to radionuclide management because at its core, the public and private recycling goals are different. At ORNL, we have specialized facilities, like IOTA, that help private and public stakeholders identify solutions.
Scientists developed most nuclear recycling technologies decades ago. A new generation can expand upon that legacy with more intentional training and professional development for nuclear scientists. Through greater workforce development in used nuclear fuel recycling, researchers like myself can proactively address the new science questions that may lie ahead.
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 is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science .
