Thermo-mechanical coupling behavior analysis for a U–10Mo/Al monolithic fuel assembly

• Main Authors: Xiaoxiao Mao, Xiaobin Jian, Haoyu Wang, Jingyu Zhang, Jibin Zhang, Feng Yan, Hongyang Wei, Shurong Ding, Yuanming Li
• Format: Article
• Language: English
• Published: Elsevier 2021-09-01
• Series: Nuclear Engineering and Technology
• Subjects: U-10Mo/Al monolithic fuel assembly; Thermo-mechanical coupling; Three-dimensional finite element model; Irradiation swelling; Irradiation creep
• Online Access: http://www.sciencedirect.com/science/article/pii/S1738573321001455

A typical three-dimensional finite element model for a fuel assembly is established, which is composed of 16 monolithic U–10Mo fuel plates and Al alloy frame. The distribution and evolution results of temperature, displacement and stresses/strains in all the parts are numerically obtained and analyzed with a self-developed code of FUELTM. The simulation results indicate that (1) the out-of-plane displacements of Al alloy side plates are mainly attributed to the bending deformations; (2) enhanced out-of-plane displacements appear in fuel plates adjacent to the outside Al plates, which results from the occurred bending deformations due to the applied constraints of outside Al plates; (3) an intense interaction of fuel foil with the cladding occurs near the foil edge, which appears more heavily in the fuel plates adjacent to the outside Al plates. The maximum first principal stresses in the fuel foil are similar for all the fuel plates and appear near the fuel foil edge; while, the through-thickness creep strains of fuel foil in the fuel plate near the central region of fuel assembly are larger, and the induced creep damage might weaken the fuel skeleton strength and raise the fuel failure risk.