22 Aug New computational tools enable better understanding of TRISO nuclear fuel ‘health’
As advanced nuclear reactor designs move forward in commercial development, many of them will use TRISO particle fuel, a highly robust uranium fuel that can withstand extreme temperatures without melting. TRISO fuel includes pyrolytic carbon, which is a graphene-based material with a disordered atomic structure.
When subjected to harsh mechanical stresses and irradiation in an advanced reactor, the fuel material’s microstructure will change or evolve, often causing undesirable changes in the overall properties and degrading the fuel’s performance.
“It’s important to understand the extent of those changes in the material because that will determine how long the fuel can be used,” says Raphaëlle David, a PhD student in nuclear engineering and engineering physics at UW-Madison. “For instance, if the material’s properties change dramatically within two months, that fuel won’t work well for a nuclear reactor.”
However, it has been challenging to sufficiently characterize how pyrolytic carbon evolves over time in extreme conditions. “There has been a huge gap in the tools that we need to describe the material’s evolution,” David says.
To address this problem, David and NEEP Associate Professor Yongfeng Zhang have developed new computational tools that provide a much better description of the complicated microstructure of pyrolytic carbon materials across multiple length scales. These tools will allow researchers to understand how the material changes over time.