A New Technology Could Shrink the Timeline for Storing Nuclear Waste From Centuries to Decades

Over 200 million liters of radioactive liquid waste, a mixture of sludge, sediment, and chemical byproducts from decades of weapons production, are waiting in old underground tanks at the Hanford Site somewhere in southeastern Washington State. A portion of it dates back to the 1940s. The tanks were never intended to hold their contents indefinitely. Since the issue essentially calls for eternity, neither was any other nuclear waste storage solution that the world has developed. For about 100,000 years, the most hazardous isotopes in spent nuclear fuel continue to pose a threat. To put that in perspective, humans that are anatomically modern have only been around for roughly 300,000 years. Depending on your perspective, asking future civilizations to oversee something we invented is either a sign of extreme irresponsibility or just the inevitable expense of nuclear energy.
The answer to the question might change in the future, according to a project being carried out at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Researchers there are working on a particle accelerator system that can change long-lived radioactive isotopes into shorter-lived ones, cutting the amount of time needed for storage from about 100,000 years to about 300 years. The work has been funded by a $8.17 million grant from the U.S. Department of Energy under the NEWTON program, which stands for Nuclear Energy Waste Transmutation Optimized Now—a name that rather boldly puts its goals right in the title.

Even though explaining it sounds like something from a science fiction movie, the physics behind it is genuinely amazing. A target of liquid mercury is hit by high-energy proton beams from the Jefferson Lab particle accelerator. The collision sets off a process known as spallation, which releases neutrons that bombard the nuclear waste material contained within the apparatus. These neutrons form bonds with the spent fuel, particularly with the long-lived fission products and minor actinides that give the waste its prolonged radioactive life. This effectively breaks them down into isotopes that decay much more quickly. Heat produced by the reaction can also be transformed into electricity. Although the term “real-life alchemy” is overused, the researchers own the comparison because they included the word “transmutation” in the project name.

In about 30 years, if NEWTON is successful, engineers could start utilizing the technology to detoxify nuclear waste using accelerator systems that are either already in place or within the realm of current engineering capabilities. If the underlying technology advances at a reasonable rate, which is a reasonable assumption given recent developments in superconducting materials, the timeline gets even shorter. In order to produce a niobium-tin compound that achieves superconducting performance at 18 Kelvin, which is much warmer than what conventional systems require, Jefferson Lab is currently working on a specific innovation that entails coating niobium accelerator cavities with a thin layer of tin. Because of this temperature differential, expensive cryogenic refrigeration equipment is no longer required, making the system as a whole much less expensive and easier to implement on a large scale.
In contrast, Finland finished building Onkalo, the world’s first permanent deep geological repository for high-level nuclear waste, in 2024. It is located on Olkiluoto Island more than 400 meters into stable bedrock and is intended to isolate spent fuel for 100,000 years using copper canisters encased in bentonite clay. It cost billions and took 25 years to construct. A similar facility is being built in Sweden. A dozen or so European nations are preparing their own. Through several presidential administrations, the United States has been debating Yucca Mountain in Nevada, a proposed repository 300 meters below the surface, without coming to a consensus. In the meantime, nuclear waste merely builds up in temporary storage that was never meant to be permanent at the power plants and processing facilities where it was produced.
The NEWTON project is important in this context, and it’s important to distinguish between what the project promises and what it has so far actually delivered. Research and optimization are still ongoing at Jefferson Lab. Instead of constructing a functional transmutation system, the $8.17 million in grant funds will be used to increase the effectiveness of the accelerator components that would eventually be needed. Researchers have not yet tested the magnetron they think could power the particle beams. Although promising, the niobium-tin cavity approach has not been tested on an operational scale. These are the real warnings, and they are important because the history of nuclear energy is replete with technologies that showed promise in the lab but proved difficult to implement.
However, there is a sense that the timing of this study is important. By 2050, the world’s nuclear capacity is expected to more than double due to decarbonization pledges, the increased demand for electricity from AI data centers, and worries about energy security heightened by disruptions in the oil market. More than thirty new reactors are being built in China. New nuclear programs are being investigated by fifty nations. Every new reactor that comes online is a source of spent fuel that needs to be disposed of. The entire ethical and practical calculation of nuclear power is altered by a technology that could reduce the issue from a 100,000-year commitment to a 300-year one. It doesn’t solve the problem, but it does make it something that human institutions, such as governments, businesses, and international organizations, can truly prepare for and handle in a reasonable amount of time. That is truly worth considering in the context of an issue that has seemed unsolvable for eight decades.