Nuclear storageStrengthening Nuclear Storage Research

When nuclear engineer Brady Hanson stood before a group of scientists seven years ago, he knew that exploring the behavior of spent nuclear fuel in prolonged storage required a rigorous approach. And he said as much.

“There’s no simple solution here,” he told his fellow researchers, who had convened to settle on a plan to exhaustively probe safety concerns tied to the extended storage and transportation of spent nuclear fuel, with a special focus on fuel cladding: the metal tubing that encases fuel pellets. “We’ll need to explore every way the fuel could degrade under realistic conditions.” 

Now, on the tail end of a decade’s worth of thorough scientific investigation that demonstrates dry fuel storage is indeed safe and secure, he feels differently. “I was wrong! The scientific method showed us what reality is—that long-term storage is safe.”

Intensively focusing on the potential for failure in nuclear fuel cladding revealed that, even under extreme but realistic conditions, each degradation mechanism was less problematic than anticipated, and each point of concern was successfully settled.

Stress from traveling by ship, train, and truck proved to be negligible, for example, and the fuel temperatures were much cooler than expected. The Office of Nuclear Energy’s Spent Fuel and Waste Science and Technology program now looks toward adding to the extensive body of research by applying the same thorough, integrated approach to the canisters that house spent nuclear fuel from the nation’s commercial nuclear reactor plants.  

On Wednesday, April 14, Hanson and a team of researchers at the U.S. Department of Energy’s Pacific Northwest National Laboratory received a boon for ongoing investigations: three completely empty, unused spent fuel canisters, each weighing over 48,000 pounds. These stainless steel containers will deepen ongoing research efforts into the forces—from infinitesimally small cracks to bumps incurred through transport—that could compromise such containers over many decades. 

A Place for Fuel
Today, nuclear power utilities store over 80,000 metric tons of spent nuclear fuel across the nation. Since the fuel will remain in dry storage longer than was expected, PNNL scientists are working to better understand exactly how the fuel behaves under extended storage conditions, how the canisters age, and the forces the two would undergo when shipped and stored for long periods.