https://doi.org/10.1051/epjconf/202124704003
OPTIMISATION OF CRITICALITY AND BURNUP CALCULATIONS IN MONK®
1 ANSWERS Software Service, Wood. Kings Point House, Queen Mother Square, Poundbury, Dorchester, United Kingdom, DT1 3BW
2 Wood. 305 Bridgewater Place, Birchwood Park, Warrington WA3 6XF
andrew.cox@woodplc.com
albrecht.kyrieleis1@woodplc.com
sam.powell-gill@woodplc.com
simon.richards@woodplc.com
tantillofrancesco87@gmail.com
Published online: 22 February 2021
The primary goal of this paper is to increase the efficiency of criticality and burnup calculations in the ANSWERS MONK® Monte Carlo code [1]. Two ways of achieving this goal are investigated as part of the H2020 McSAFE Project: creating a unified energy grid for all materials in the model, and reducing the spread in variances of fluxes for depletable materials using a generated optimised importance map. The average tracking speedup factor across all cycles of all burnup calculations ran using the unified energy grid, at base temperature, was found to be 1.96. For criticality calculations at 400K with runtime Doppler broadening, the unified grid approach gave a total speedup factor of 7.32. This demonstrates the potential importance of this method to reduce the calculation time with models with runtime Doppler broadening. The use of the generated optimised importance map has been demonstrated to significantly reduce the variance in the standard deviations on the fluxes in the fuel pins across two different test cases. If a solution is required in which the standard deviation in none of the fuel pins exceeds 5% it was found that the number of scoring stages required was more than halved, highlighting the potential for the outlined methodology to speedup burnup credit calculations.
Key words: Optimisation / MONK / Unified Energy / Importance
© The Authors, published by EDP Sciences, 2021
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
