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Title: Automatic Mesh Adaptivity for Hybrid Monte Carlo/Deterministic Neutronics Modeling of Fusion Energy Systems

Conference ·
OSTI ID:1096307

Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); ITER Organization, St. Paul Lez Durance (France)
Sponsoring Organization:
USDOE Laboratory Directed Research and Development (LDRD) Program
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
1096307
Resource Relation:
Conference: 11th International Symposium on Fusion Nuclear Technology, Barcelona, Spain, 20130916, 20130920
Country of Publication:
United States
Language:
English