INL gains nuclear fuel insight with new examination approach

Idaho National Laboratory
Oct 4, 2011

Any materials scientists will tell you they can get a better understanding of how a substance behaves if they know what’s happening at the microscopic scale. For example, we know that sunlight damages rubber and plastics because UV rays cause molecules to cross-link to each other, which ultimately reduces elasticity.

Detailed microscopic insights are harder to come by for those studying how nuclear fuels and structural materials behave inside reactors. It’s important for engineers to understand how new fuel types stand up to prolonged irradiation before these materials are used in commercial power reactors. But such understanding can be a challenge when it comes to handling and studying extremely radioactive materials.

Substances irradiated inside a test reactor are too radioactive to safely work with using the same techniques that other materials scientists employ. Irradiated fuel must be handled at a distance using remote manipulators, which can hinder the precision required to prepare samples for state-of-the-art microscopic analysis.

Idaho National Laboratory researchers have now cleared that hurdle. They recently demonstrated a new sample preparation technique that makes it easier for researchers to examine irradiated fuel at the nanoscale. This accomplishment revealed material behavior that suggests increased stability of a new type of reactor fuel. Further study and improvement in nuclear fuel performance are now much more attainable, said Dennis Keiser, a researcher in INL’s Nuclear Fuels and Materials Division.

“If you look at the literature, microstructure information on irradiated fuel is very limited,” he said. “This new preparation technique will allow people with interest in different fuel types to potentially have access to new information about nuclear fuel behaviors at a very fine scale. It will also provide key information for computer models, which need data on a fine scale to make models that accurately represent fuels and materials behavior.”
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