The development of fuel management code TRACS for HFETR based on Unstructured-mesh variational nodal method. (February 2022)

• Record Type: Journal Article
• Authors: Zhuang, Kun; Zheng, Yong; Xu, Fei; Li, Ting; Lu, Wei; Shang, Wen; Yan, Jiangtao; Wang, Sipeng; Tang, Xiaobin
• Is Part Of: Annals of nuclear energy. Volume 166(2022)
• Publication Date: 2022-02
• Subjects: HFETR -- Unstructured-mesh -- Fuel management -- Criticality searching; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2021.108807
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: A fuel management code named TRACS was developed for HFETR based on unstructured-mesh variational nodal method. 2 types of typical benchmarks with different irradiation channel were employed to verify TRACS code. TRACS can be applicable for modeling HFETR of complex geometry and is in a good accuracy with OpenMC code. Abstract: High Flux Engineering Test Reactor (HFETR) focuses on the irradiation test of reactor fuel elements, thus the accurate determination of power or flux distribution becomes important. Since HFETR contains complex geometry assembly and different types of irradiation channels, the traditional simulation methods such as Monte Carlo method and deterministic method based on rectangle and hexagonal mesh are not applicable in taking into account calculation accuracy and efficiency. In this study, based on "two-step" calculation scheme, a fuel management code named TRACS was developed. Homogenization of few-group cross-sections was performed by KYLIN-II lattice code, and reactor core calculation was performed by unstructured-mesh variational nodal method. Criticality position of control rod searching adopts difference method, and micro-depletion calculation is performed by solving microscopic burnup equation using an open source matrix exponential solver EXPOKIT of Chebyshev rational approximation method. Finally, two benchmarks of HFETR sample model with different irradiation channels were used to verify TRACS code, and the results by Monte Carlo code OpenMC serve as reference. The comparison results show that the keff error is less than 300 pcm for both two cases, and the relative power error of nearly all the fuel assembly and regions in irradiation assembly at both BOL and EOL stay below 5%, and the critical positions of control rods between TRACS and OpenMC during reactor operation are nearly the same. Overall, TRACS agrees well with OpenMC, and it can be used for fuel management calculation of HFETR with complex geometrical irradiation channel.