Scholar: Manuel Retana
Major: Mechanical Engineering
Faculty Mentors: Dr. Miles Greiner & Dr. Mustafa Hadj-Nacer
Research Topic: Evaporation Model Development for Forced Helium Dehydration Process of Used Nuclear Fuel Canister
Abstract: After being used, nuclear fuel assemblies are stored in a water pool for some period of time, then transferred to a canister underwater. The canister is then lifted and drained. Some water may remain at the bottom and in the crevices of the canister. Essentially, all water and moisture should be removed to prevent corrosion and/or formation of a combustible mixture of hydrogen and oxygen in the canister. Forced Helium Dehydration (FHD) is a process used for high burnup fuel in which heated helium is circulated through the canister to evaporate and remove moisture. The objective is to determine the amount of water remaining in the canister after FHD. In this work, a geometrically-accurate, three-dimensional CFD model of a nuclear fuel canister is created to simulate FHD. ANSYS/Fluent CFD code provides a multiphase heat and mass transfer analysis to assess if FHD meets dryness requirements imposed by the U.S. NRC before the canisters are approved for long-term storage. The phase change model needs to consider model boiling, free surface evaporation, diffusion, and condensation to accurately simulate FHD. First, a simple 3D model of a nuclear fuel assembly with a 3×3 array of heated rods is created. This model is used to test the developed evaporation model as it does not require many simulation efforts (500,000 elements). Then, once the evaporation model is validated, it will be applied to a 1/8th full scale model (60 million elements) of a nuclear fuel canister. A User Defined Function (UDF) will be used to apply the evaporation model to the simulations. Currently, both the 3×3 and the 1/8th models have been completed and verified. The evaporation model will be completed and validated against analytical results. Finally, the evaporation model will be applied to the 1/8th model to simulate FHD and estimate the remaining amount of water.
New Scholar: 2016 cohort
Graduating with a Baccalaureate Degree: 2017