Year: 2026
Type: article
Abstract: Reliable simulation of graphite-moderated pebble bed reactors requires validation against integral experiments. This work validates the latest SCALE development version against the HTR-PROTEUS benchmark suite from the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhE). Eleven critical configurations were analyzed, including hexagonal close-packed (HCP), columnar hexagonal point-on-point (CHPOP), andnominally random pebble-bed arrangements, with variations in moderator to-fuel ratio and simulated water-ingress conditions. Criticality calculations were performed with the SCALE’s Shift Monte Carlo code using multiple nuclear data libraries in both continuous-energy and multigroup modes, and explicit modeling of pebbles. Recent Shift enhancements in the mesh acceleration for such stochastic geometries made the simulations efficient. In addition to criticality, the effective delayed neutron fraction and selected control rod worths were evaluated. Nuclear data sensitivity and uncertainty analyses were also performed. The calculations reproduced the main benchmark trends, with both ENDF/B-VIII.0 and ENDF/B-VIII.1 libraries yielding smaller keff bias, while the propagated nuclear-data induced uncertainty in keff remained near 0.7% for ENDF/B-VII.1, ENDF/B-VIII.0, and ENDF/B-VIII.1. These results support the use of SCALE for high-fidelity analysis of graphite-moderated pebble bed reactors systems.
Source: Progress in Nuclear Energy
Authors: Donny Hartanto, Rabab R. Elzohery, Yves E. Robert, Friederike Bostelmann, William Wieselquist
Institution: Oak Ridge National Laboratory
Language: English
Subfield: Nuclear Energy and Engineering
Field: Energy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,930
OpenAlex ID: W7214038202