Researchers uncover hidden pore network within nuclear fuel

[Marlin]

Researchers uncover hidden pore network within nuclear fuel

https://news.mit.edu/2026/researchers-uncover-hidden-pore-network-within-nuclear-fuel-0813

[Core Content]

Researchers from MIT, Idaho National Laboratory, and Brookhaven National Laboratory used high-energy synchrotron X-ray computed tomography to map three-dimensional pore networks in irradiated U-10Zr metallic fuel. The study analyzed samples from the decommissioned Fast Flux Testing Facility to determine how internal fuel structures evolve and interact with protective cladding during fission.

These findings challenge existing two-dimensional models that characterize pores as simple spheres. By revealing complex, interconnected pore channels that facilitate the migration of fission products and lanthanides, the data provides a clearer understanding of fuel swelling and thermal conductivity. This research assists in refining performance simulations for advanced sodium-cooled fast reactors and optimizing fuel system longevity.

Researchers analyzed how the nuclear fuel U-10Zr changes when it undergoes nuclear fission in a reactor and how it interacts with the protective fuel cladding surrounding it. The findings could help keep some nuclear reactors running for longer, while informing the next generation of nuclear reactor fuel systems.

The moment a nuclear reactor begins operation, a complex chain of events is initiated within the fuel: Heavy atoms split into fission products, knocking other atoms out of place and creating defects that can change how the fuel swells, transfers heat, and reacts chemically over time.

Understanding those processes is key to understanding how safe and efficient a nuclear reactor will be. But even for some of the most-studied fuel types, the mechanisms controlling those processes are unclear.

Read the full article at MIT News | Massachusetts Institute of Technology:
https://news.mit.edu/2026/researchers-uncover-hidden-pore-network-within-nuclear-fuel-0813