NUCLEAR WASTE Technology to Reduce the Impact of Used Nuclear Fuel
Transmutation technologies can significantly reduce the mass, volume, activity and lifespan of commercial used nuclear fuel (UNF) by converting long-living hazardous isotopes into materials that decay more quickly.
Two projects led by researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have been awarded just over $10 million from the DOE’s Advanced Research Projects Agency-Energy (ARPA-E). The funding is part of the Nuclear Energy Waste Transmutation Optimized Now (NEWTON) program, which aims to make the conversion of U.S. commercial used nuclear fuel (UNF) economically viable within 30 years.
Transmutation technologies can significantly reduce the mass, volume, activity and lifespan of UNF by converting long-living hazardous isotopes into materials that decay more quickly. This reduces the duration needed for long-term storage and improves overall economy and safety of operations.
“We are incredibly proud of this planned transformational work in nuclear waste transmutation, which has earned well-deserved recognition and support from the DOE’s NEWTON program,” said Temitope Taiwo, director of Nuclear Science and Engineering at Argonne. “The innovative approach positions Argonne at the forefront of sustainable nuclear technology solutions.”
The first Argonne project was awarded $7 million and is led by Taek K. Kim, a senior nuclear engineer and manager of Nuclear Systems Analysis. The project, titled “Liquid Lead Suspended Fuel Subcritical Fission Blanket for Nuclear Waste Transmutation,” focuses on a new type of transmutation process. It also uses innovative separation methods — centrifugal force — to remove the waste by-products from the process. Fission is the process of splitting an atomic nucleus into two or more smaller nuclei, releasing a large amount of energy.
The project aims to transmute the entire U.S. stockpile of minor actinides within 30 years, reducing the nuclear fuel mass by 28 times, which is roughly equivalent to shrinking a large swimming pool filled with used fuel down to the size of a small hot tub. It will also decrease radiotoxicity management time 333-fold.
“I am very excited to receive funding from the NEWTON program to advance this brand-new technology,” said Kim. “This method uses physics-based separation instead of conventional chemical separations such as PUREX, making it a separation technology that is more secure and more difficult to use for nefarious purposes.”
The proposed transmutation system uses a proton accelerator to start fission in a liquid lead setup containing tiny minor actinide particles — the heavy, radioactive elements near the bottom of the periodic table. As the minor actinide particles fission, the two new smaller nuclei are ejected from the particle and can be separated from the actinide particles by centrifugal methods in a recycling system.
More technical details about the project are available on the ARPA-E website.
Argonne’s second NEWTON award-winning project is in partnership with DOE’s Fermilab National Accelerator Laboratory. Michael Kelly, an accelerator physicist in Argonne’s Physical Science and Engineering directorate, leads the project, “Nb3Sn Proton Driver Linac for Accelerator Driven Systems.” The project is focused on developing advanced superconducting cavities used in particle accelerators.
Particle accelerators could play a significant role in the management of the 90,000 metric tons of UNF at U.S. nuclear plants. Made from materials that conduct electricity without resistance when cooled to very low temperatures, superconducting cavities are specialized components stacked together in particle accelerators to efficiently propel charged particles, like protons, to high speeds.
An accelerated proton beam can generate an intense flux of neutrons, uncharged subatomic particles that are useful for probing materials at the atomic scale. When directed at radioactive waste inside a nuclear reactor, these neutrons multiply and can transform radioactive waste into less harmful materials. The team is developing advanced superconducting cavities using a thin film of niobium-tin (Nb3Sn) to reduce the size and cost of accelerators while improving their reliability and efficiency.
Between both projects, Argonne scientists are working on the most critical pieces of making transmutation a reality: the accelerator and proton beam, as well as the target and reactor.
Marguerite Huber is Communications Coordinator at Argonne National Laboratory. The article was originally posted to the website of Argonne National Laboratory.
