Application of global variance reduction methods for the calculation of γ radiation field in a large space

被引：0

作者：

Liu L. ^{[1
]}

Zuo Y. ^{[1
]}

Niu S. ^{[1
]}

Zhu J. ^{[1
]}

Shang P. ^{[1
]}

Wang X. ^{[1
]}

机构：

[1] Northwest Institute of Nuclear Technology, xi'an

来源：

He Jishu/Nuclear Techniques | 2024年 / 47卷 / 02期

关键词：

Global Variance reduction; Global weight window; Large space γ radiation field; Monte Carlo simulation; Volume modifying factor;

D O I：

10.11889/j.0253-3219.2024.hjs.47.020602

中图分类号：

学科分类号：

摘要：

[Background] The direct simulation of the γ radiation field in a large space has a very low calculation efficiency. [Purpose] This study aims to apply the global variance reduction (GVR) method to the calculation of the γ radiation field in a large space. [Methods] Firstly, the volume correction factor was introduced for modifying the lower limit of the weight window wth to address the over-splitting problem caused by the volume difference between the counting cells/grids. The global quality factor (FOMG factor) calculated by the flux-based GVR method using the volume correction was 39 times higher than that obtained by direct simulation. Then, a non-counting area correction method was proposed to address the time-consuming problem encountered in non-counting area calculation while the FOMG factor was further improved by 40%. Finally, based on both the volume correction and non-counting area correction, the calculation of the γ radiation field were compared with that of seven GVR methods based on the particle error, weight, track, number, energy, collision and flux, respectively. The smoothing factor SI was introduced into the flux-based GVR method for results further analysis. [Results and Conclusions] The results show that the FOMG factor calculated by the seven GVR methods is about 2~3 orders of magnitude higher than that obtained by direct simulation, and the standard deviation σ is reduced by 2~3 orders of magnitude. The FOMG factor calculated by the weight-based GVR method is 2 304 times higher than that obtained by direct simulation; this value yields the best variance reduction effect among all GVR methods. As SI increases, the lower limit of the weight window wth of the simulation decreases, and the FOMG factor first increases and then decreases. When SI=0.8, the calculated FOMG factor has the largest value, which is 3 246 times higher than that obtained by direct simulation. © 2024 Science Press. All rights reserved.

引用

共 23 条

[1] ZUO Yinghong, NIU Shengli, SHANG Peng, Et al., Weight window variance reduction method for simulating long distance γ-ray transport, Modern Applied Physics, 11, 1, (2020)
[2] Booth T E., MCNP variance reduction examples, (2012)
[3] LI Changkai, TANG Xiaobin, YUE Aizhong, Pulse-height tally variance reduction in deep penetration problem, Nuclear Techniques, 38, 3, (2015)
[4] WANG Song, YANG Yongxin, LU Changbing, Et al., Research of variance reduction techniques for large space dose calculation[J], Nuclear Power Engineering, 39, 6, pp. 116-121, (2018)
[5] WANG Jianguo, NIU Shengli, ZHANG Dianhui, Et al., Manual of parameters of high altitude nuclear explosion effect, (2010)
[6] Davis A, Turner A., Comparison of global variance reduction techniques for Monte Carlo radiation transport simulations of ITER[J], Fusion Engineering and Design, 86, 9–11, pp. 2698-2700, (2011)
[7] van Wijk A J, Van den Eynde G, Hoogenboom J E., An easy to implement global variance reduction procedure for MCNP[J], Annals of Nuclear Energy, 38, 11, pp. 2496-2503, (2011)
[8] Zheng Y, Qiu Y F, Lu P, Et al., Improvements of the on-the-fly MC variance reduction technique with dynamic WW upper bounds[J], Nuclear Fusion, 62, 8, (2022)
[9] Zheng Y, Qiu Y F, Lu P, Et al., Verification of the on-the-fly global variance reduction technique on Monte Carlo global coupled neutron photon shielding calculations[J], Fusion Engineering and Design, 171, (2021)
[10] WANG Mengqi, ZHENG Zheng, MEI Qiliang, Et al., Application of global variance reduction method to spent fuel dry storage cask shielding calculation[J], Atomic Energy Science and Technology, 53, 5, pp. 884-892, (2019)

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