Abstract:

In aluminum-clad spent nuclear fuel (ASNF) dry storage systems, residual water undergoes radiolysis, generating hydrogen that can compromise storage integrity. This hydrogen production is represented through a chemical reaction network, modeled as a system of coupled ordinary differential equations. To mitigate these risks, Savannah River National Laboratory (SRNL) conducted fuel-drying experiments to assess thermal pretreatment strategies for reducing residual water. Surprisingly, SRNL’s findings differ markedly from similar studies at Idaho National Laboratory (INL), prompting questions about the reliability of current pretreatment procedures.

To explore these discrepancies, we use the open-source MOOSE framework, and we employ the Tritium Migration Analysis Program (TMAP8), built on MOOSE to simulate hydrogen transport within SRNL’s stainless steel mini-canisters. These simulations involve multiphysics transport models requiring careful choices of finite element discretization, integration of and validation against experimental data, nonlinear solvers, and interface conditions. Balancing computational efficiency with the complexity of coupled multiphysics systems is a central challenge.

Accurate modeling of these processes is critical for predicting long-term behavior in spent nuclear fuel storage and for developing robust, safe storage strategies. This work highlights how mathematical modeling—through systems of ordinary and partial differential equations, numerical methods, and multiphysics simulation—plays a pivotal role in addressing real-world engineering and safety problems.

Bio:

Dr. Evan Butterworth is a Postdoctoral Research Associate in the Materials Performance & Modeling group at Idaho National Laboratory (INL). Evan earned his Ph.D. in computational mathematics from Clemson University, where he developed and implemented high-order temporal integration schemes for nonlinear adsorption problems to efficiently model membrane-based virus purification processes.

His research interests include mathematical modeling & simulation, numerical PDEs, finite element analysis, and optimization. At INL, Evan applies his expertise in applied mathematics to address a wide range of interdisciplinary challenges, designing and implementing multiphysics models for additive manufacturing, spent nuclear fuel storage, and nuclear fusion applications.

Beyond research, Evan serves as the social committee chair for the INL Postdoctoral Association, organizing events that strengthen connections among postdocs and foster engagement with the broader Idaho Falls community.