Effects of U-Mo Irradiation Creep Performance on the Thermo-Mechanical Coupling Behavior in U-Mo/Al Monolithic Fuel Assemblies

Frontiers in Energy Research

Haoyu Wang¹  Lin Zhang¹  Yuanming Li¹  Xiaoxiao Mao²  Xiaobin Jian²  Feng Yan²  Yongzhong Huo²  Jingyu Zhang²  Shurong Ding² 

[1] Chengdu, China;Shanghai, China;

关键词: U-Mo/Al monolithic fuel assembly;    irradiation creep;    thermo-mechanical behavior;    irradiation swelling;    fission gas bubbles;    skeleton stress of porous fuel foil;   

DOI  :  10.3389/fenrg.2021.676881

来源: Frontiers

【 摘 要 】

To obtain the optimized fuel performance, the effects of U-Mo irradiation creep rate coefficient on the thermo-mechanical behavior of a fuel assembly are investigated. In this study, three cases of creep rate coefficient are considered. The distribution and evolution results of temperature, displacement, stress/strain and fuel foil micro-structure are analyzed. The simulation results indicate that with the increase of creep rate coefficient 1) the temperature field in the fuel assembly changes slightly; 2) the maximum out-of-plane displacements in the side plates decrease slightly; the maximum out-of-plane displacements in the fuel plates adjacent to the outside Al plates rise distinctly, induced by the enhanced bending deformation contributions; 3) the peak values of the first principal stresses and skeleton normal stresses in the fuel foils are reduced, while the through-thickness creep strains are enlarged; 4) with an increase of fuel creep rate coefficient from 500 × 10−22 mm3/(fission MPa) to 2,000 × 10−22 mm3/(fission·MPa), the maximum Von Mises stress in the fuel cladding decreases by ∼24% on the 308th day. This work is helpful for advanced fabrication and optimization design of U-Mo/Al fuel assemblies.

【 授权许可】

CC BY