December 2024

Journal

Ordered Particle Packing in Dense TRISO/SiC Fuel Elements and Preliminary Assessment of Neutronic and Thermomechanical Characteristics

By:
Ade, Brian J; Schappel, Daniel P; Betzler, Benjamin R; Helmreich, Grant W; Talamo, Alberto; Richardson, Michael D; P trammel, Michael; Jolly, Brian; Schumacher, Austin T; Terrani, Kurt
Journal Name:
Nuclear Science and Engineering
Page Number:
1517-1538
Volume:
196
Issue Number:
12
Publication Date:
December 5, 2024
View DOI Listing:
https://doi.org/10.1080/00295639.2022.2049995

Abstract

Detailed analysis of the particle distribution in Transformational Challenge Reactor fuel elements indicates that particle packing is not random; instead, it follows a relatively ordered structure near fuel element surfaces. Discrete particle neutronic simulations indicate that the core reactivity is not impacted when assuming homogenization of particles with the silicon carbide matrix. However, the neutronic power distribution resulting from the ordered packing structure indicates that the highest-power particles reside at the top and bottom of the fuel elements and nearest the YH1.85 moderator rods. The power distribution results were applied to thermo-mechanical simulations using mesh-based power distributions. Previous results indicated high stress at the bottom of the fuel element, where packing is most ordered. To reduce this stress concentration, additively manufactured protrusions were added to the bottom of a test fuel element to disrupt dense particle packing. These protrusions reduced the overall power peaking, but the thermomechanical simulations did not indicate a significant change in the fuel element’s maximum stress or failure probability.