Session: OAC-04-02 Transportation of Radioactive and other Hazardous Materials II

Paper Number: 61716

Start Time: Thursday, July 15, 2021, 09:00 AM

61716 - Modeling and Sensitivity Analysis of the TN-32 UNF Cask: Comparison With the HBU Project Data 

The High Burnup (HBU) Spent Fuel Data Project is a demonstration and data collection project created to investigate the performance of high-burnup used nuclear fuel (UNF) during storage. A TN-32 UNF cask was selected, instrumented, and loaded with UNF assemblies in order to generate data for analysis and comparison for licensing and model validation. The Extended Storage Collaboration Program (ESCP) International Thermal Modeling Benchmark Project is a modeling project based off the HBU project experimental conditions and data. The ESCP project is a collaboration amongst many international thermal modeling groups with the goal of understanding and quantifying uncertainties and biases in thermal modeling codes with respect to the modeling of UNF casks. Phase 1 of this project evaluates the variability between participants’ models when given a common set of inputs to better understand code-to-code variations. Phase 2 consists of exploring sensitivities of the cask model to better understand the experiment-to-model discrepancies.

The objective of this work is to construct a three-dimensional (3D), one-eighth homogenous fuel region model of the TN-32 UNF cask in the ANSYS simulation package for comparison with the HBU and ESCP projects. Simulations are carried out using ANSYS/FLUENT for geometry, heat transfer, flow, and boundary conditions recommended by the ESCP project. Simulation results, including peak cladding temperature (PCT) and external and internal temperatures, are compared with experimental results from the HBU project. A sensitivity analysis is conducted to determine the effect the different assumptions made by the ESCP project on the results. This sensitivity analysis indicated that internal natural convection have a significant effect on the prediction of internal temperatures, given that the drain holes at the base of the basket are modeled. Additionally, the results indicate that a small variation in the thickness of the peripheral basket-rail gap has a significant effect on the internal temperatures.

Presenting Author: Megan Higley University of Nevada, Reno

Authors:

Megan Higley University of Nevada, Reno
Mustafa Hadj-Nacer University of Nevada, Reno
Miles Greiner University of Nevada, Reno