Imaging innovation advances nuclear materials qualification

To better understand how nuclear fuel cladding behaves in accident conditions, it helps to get the full picture.

Researchers at Oak Ridge National Laboratory have captured first-of-a-kind optical measurements during accident testing of commercially irradiated nuclear fuel cladding.

The measurements represent a significant innovation in a complex testing environment. Gathering optical data of irradiated materials requires electronics that can withstand the heat and operate remotely in a high radiation environment. To solve that problem, an ORNL team representing the lab's expertise across materials and nuclear science modified a camera system to remotely capture continuous, high-quality photos of samples from outside a heavily shielded area called a hot cell.

Using a technique called digital image correlation (DIC), the test captured detailed measurements of the cladding's behavior during a simulated loss-of-coolant accident, an uncommon event but an important test in qualifying nuclear materials and fuel.

"DIC gives us a clearer, more complete picture of what happens during these rare events," said ORNL's Mackenzie Ridley. "These measurements feed models that can refine and expand safety qualification parameters for high burnup and accident-tolerant fuel."