Modeling, Performance Assessment, and Nodal Data Analysis of TRISO-Fueled Systems with Shift

Modeling Enhancements and Demonstration of Shift Capabilities for PBRs and MSRs

“…Shift was applied through the Omnibus frontend using an ORANGE model. Using the ORANGE geometry enabled the use of recent enhancements for PBR modeling, as reported in previous work by the authors [13]. The following sections cover additions to the ORANGE geometry implemented for the GPBR modeling effort, the developed Shift GPBR model, the application of INL's capabilities for equilibrium core search, and ideas for future work supporting PBR modeling with Shift.…”

“…Applying the capability for automatic random placement of TRISO particles within a fuel zone led to a unique TRISO particle distribution in each of the 354 unique pebbles. To improve runtime and make use of latest enhancements in ORANGE, the pebbles were placed at specific coordinates in the fuel region using ORANGE's replica capability [13], with the coordinates determined by INL using a Discrete Element Method (DEM) solver [14].…”

“…The Serpent calculation shows a significantly shorter run time, but a slightly larger memory footprint than Shift due to the use of Delta tracking. With a 5x increase in runtime compared to Serpent and a slightly smaller memory footprint, the Shift result is still considered excellent given that the modeling and simulation of this complex model with both randomly distributed TRISO particles and randomly distributed pebbles was only recently made possible with the uniform grid accelerations [13].…”