Modelling explicit fracture of nuclear fuel pellets using peridynamics

JOURNAL OF NUCLEAR MATERIALS

卷:467

Article

Mella, R.¹  Wenman, M. R.^2,3 

[1] Def Acad UK, HMS Sultan, Nucl Dept, London PO12 3BY, England

[2] Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2AZ, England

[3] Univ London Imperial Coll Sci Technol & Med, Ctr Nucl Engn, London SW7 2AZ, England

关键词: Peridynamics modelling;    Nuclear fuel;    Pellet-cladding interactions;    UO2;    Fracture;   

DOI  :  10.1016/j.jnucmat.2015.08.037

来源: Elsevier

【 摘 要 】

Three dimensional models of explicit cracking of nuclear fuel pellets for a variety of power ratings have been explored with peridynamics, a non-local, mesh free, fracture mechanics method. These models were implemented in the explicitly integrated molecular dynamics code LAMMPS, which was modified to include thermal strains in solid bodies. The models of fuel fracture, during initial power transients, are shown to correlate with the mean number of cracks observed on the inner and outer edges of the pellet, by experimental post irradiation examination of fuel, for power ratings of 10 and 15 W g(-1) UO2. The models of the pellet show the ability to predict expected features such as the mid-height pellet crack, the correct number of radial cracks and initiation and coalescence of radial cracks. This work presents a modelling alternative to empirical fracture data found in many fuel performance codes and requires just one parameter of fracture strain. Weibull distributions of crack numbers were fitted to both numerical and experimental data using maximum likelihood estimation so that statistical comparison could be made. The findings show P-values of less than 0.5% suggesting an excellent agreement between model and experimental distributions. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free