NPRE researchers help prepare for future transport of spent nuclear fuel

Currently, while the federal government mulls policies to identify a permanent solution to store spent nuclear fuel, the material is kept in casks at reactor sites. In the meantime, University of Illinois nuclear scientists are preparing for the eventual safe transport of the casks by developing means to monitor them internally.

A multi-disciplinary, multi-university team including Tomasz Kozlowski, Ling-Jian Meng and Rizwan Uddin of Nuclear, Plasma, and Radiological Engineering at Illinois are participating in the $3 million Department of Energy Consolidated Integrated Nuclear Research (CINR) project. Led by the University of Houston, researchers from the University of Southern California, the University of Minnesota, the Pacific Northwest National Laboratory and Anatech Corporation also are taking part.

The project’s main objective is developing a method of determining potential damage or degradation of the casks’ internal components during normal transportation conditions, as well as hypothetical accident conditions.

“You have a cask that has to be transported, and then something happens,” Kozlowski said of the possibilities that will be considered. “We need to know how to judge what happens inside the cask without tearing into it.”

One consideration will be the possibility of human error in misloading fuel into the casks prior to transport. “We have to do risk analysis: Which other loading scenarios are there, and what are the chances of making this mistake?” Uddin said. “The arrangement in which spent fuel is loaded into the cask is important to avoid criticality.”

Uddin’s responsibility in the project will be to consider misloading scenarios, while Kozlowski will calculate burnup, the measurement of how much energy has been extracted from the fuel, and isotopic composition of the used fuel. Together, they will work on criticality evaluations.

The scientists will examine the viability of the casks in case of an accident, particularly after a long duration in storage.

Complementary to these computational efforts, the Meng team will be working with other investigators to develop non-destructive imaging techniques to allow assessment of the physical status of the fuel rods inside the casks. Meng’s team will be specifically looking into the possibility of using time-tagged neutron to probe inside the casks and to obtain information on potential damage and dislocation of the fuel rods after transportation.

His team’s work, using radiological imaging techniques to help determine the extent of potential damage or degradation of internal components, is particularly unique to this study.