Argonne National Laboratory’s groundbreaking experiment sheds light on the behavior of liquid plutonium oxide at extreme temperatures, paving the way for safer nuclear energy systems.
Boundary Pushing Nuclear Science
The 2011 Fukushima-Daiichi disaster served notice to the nuclear industry and sparked a great deal of research, study and introspection as it examined opportunities to improve safety standards.
A group of scientists and engineers at the Argonne National Laboratory have been investigating how nuclear fuel materials behave after being heated up to very high temperatures. We’ll focus their attention on molten plutonium oxide (PuO2), a vitally important component of next-generation nuclear reactors, the better to learn its structure and properties.
However, the study of PuO2 is not trivial due to Its radioactiveand hazardous nature. But they were on a quest to extract the core data necessary for developing new, safer and cleaner nuclear energy systems.
Major advance in the processing of molten plutonium oxide
The Argonne researchers used the high-powered X-ray beams at the Advanced Photon Source, a U.S. Department of Energy user facility, for their experiments. The technique makes the experiment “container-less,” allowing them to measure the structure of the molten material without fear of contamination from interacting with a container. By levitating small samples of PuO2 and heating them up to as high as 3,000 K, it was possible for researchers to image liquid plutonium at temperatures comparable to its natural environment in nuclear reactors.
This pioneering work built on their previous success in studying molten UO2 to tackle the considerable challenges of working with PuO2. The work, published in the prestigious journal Nature Materials, showed that PuO2 retains a small covalent fraction in its liquid structure like that found for the nonradioactive analog cerium oxide.
In a recent Physical Review B paper, the team reports valuable insights on the low temperature behavior of actinide oxides that are essential to guide theoretical predictions for designing next-generation nuclear reactors with higher safety margins and thermodynamic efficiencies. This work spurred the creation of new state-of-the-art machine learning methods, able to accurately predict the intricate electronic structure of these materials and therefore also their safety properties.
Conclusion
Research on molten plutonuim oxide supports nuclear safety. By untangling the intricate dancing between atoms in this key reactor fuel material at high temperatures, they have now laid a path for new designs of safer and more efficient nuclear energy systems to build on their stellar safety reputation. The expertise that had been gathered to form the ATRI contributed in evidence that advancements in science and innovation were more than capable of being able to tackle the problems sooner or later posed with Nuclear Energy.
