A method for calculating the assembly bowing reactivity coefficients in sodium fast reactor. (1st June 2021)

• Record Type: Journal Article
• Authors: Wang, Yongping; Chen, Jianda; Wei, Linfang; Yin, Huabei; Zheng, Youqi; Du, Xianan
• Is Part Of: Annals of nuclear energy. Volume 155(2021)
• Publication Date: 2021-06-01
• Subjects: Assembly bowing reactivity -- Sodium fast reactor -- Perturbation theory -- Neutron transport equation; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2021.108176
• Languages: English
• ISSNs: 0306-4549

Abstract

Highlights: A method for the calculation of assembly bowing reactivity coefficients in sodium fast reactor is introduced. The 2D and 3D problem are evaluated. The numerical results show good accuracy, compared with Monte-Carlo simulations. Abstract: This paper proposed a method for the calculation of assembly bowing reactivity coefficients in sodium fast reactor. Firstly, in the core-analysis nodal method, a fuel assembly and a thin layer of sodium around it are treated as a node in the radial plane. Then the assembly bowing is discretized to radial displacements of the assembly region in each axial segment. Based on perturbation theory, the reactivity change caused by radial displacement can be expressed as the difference of reaction rates and leakage. The difference of total, scattering and fission reaction rates can be calculated by flux reconstruction and the corresponding cross sections. To take the leakage into account, this paper proposed a scheme to approximately evaluate the change of leakage by the gradient change of flux. Finally, the numerical results of the 2D and 3D problem show that this method achieves acceptable accuracy in these problems.