Improvements on the method of ultra-fine-group slowing-down solution coupled with method of characteristics on irregular geometries. (February 2020)

• Record Type: Journal Article
• Authors: Zhang, Qian; Shuai, Qin; Zhao, Qiang; Liang, Liang; Wu, Hongchun; Cao, Liangzhi
• Is Part Of: Annals of nuclear energy. Volume 136(2020)
• Publication Date: 2020-02
• Subjects: Ultra-fine-group -- Slowing-down equation -- Method of characteristic -- Resonance self-shielding; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2019.107017
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: Improvements are proposed to enhance the UFG slowing-down calculation based on MOC. The lethargy is optimized to save half of the UFG-MOC calculation time. The pre-tabulated CP table can speed up the UFG-MOC calculation by 30 times. Abstract: Ultra-fine-group slowing down solution coupled with method of characteristics is a rigorous resonance calculation method which can handle complicated geometry and spectrum. However, the original approach is time-consuming due to large amount of computational cost of method of characteristics. In this research, investigations are carried out on the computational efficiency with optimized lethargy and the pre-tabulated CP table generated by MOC. Calculations of multiple types of problems are performed, and numerical results show that these techniques can obtain improved efficiency on complicated geometry and complicated neutron spectrum problems, while maintain the accuracy of resonance self-shielding. For universal problems, the optimized lethargy can save half of the calculation time comparing to the original lethargy. For the problem with local heterogeneity tested in this study, the pre-tabulated CP table generated by MOC can speed up the calculation by 30 times.