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. (C) 2014 Elsevier B.V. All rights reserved.
Detailed profiles of nuclear heating and radiation damage parameters were determined in ITER blanket modules at different poloidal locations. The results indicate that the nuclear parameters are sensitive to the configuration and material composition with enhanced steel heating and helium production in regions with large water content.
Data for 40 of the 71 isotopes/elements in FENDL-2.1 were taken from ENDF/B-VI.8. Following the release of ENDF/B-VII.0 we performed a preliminary assessment for changes made in data of these 40 isotopes/elements. We compared the relevant cross sections in the two libraries. In addition, we carried out MCNP calculations for a calculational benchmark representative of an early ITER design that was utilized during the FENDL development process. In addition, we performed 3-D calculations for an inertial fusion power plant conceptual design. It is concluded that modifying FENDL-2.1 to include the most recent ENDF/B-VII.0 is not urgently needed for ITER analysis. On the other hand, the larger changes in calculated ICF target neutronics parameters and tritium breeding ratio confirm the need for updating FENDL-2.1 for use in analysis of fusion systems beyond ITER. Additional calculations are in progress for integral experimental benchmarks to fully understand the impact of data changes introduced in ENDF/B-VII.0.