NuFuel & MMSNF 2015

First Workshop on Research into Nuclear Fuel in Europe
and Materials Modeling and Simulation for Nuclear Fuels Workshop
Karlsruhe, Germany, November 16th to 18th, 2015

Updated: Tue 08 Dec 2015, 14:27

Talk 6.4: Modelling Pellet Relocation in PELICAN, a Finite Element Model for Pellet-Clad Interaction in AGR & PWR Fuel

Thomas Haynes, M.R. Wenman.
  • Department of Materials and Centre for Nuclear Engineering, Imperial College London, London. SW7 2AZ.


Pellet fragment relocation is of importance in fuel as it affects the effective gap between the clad and fuel, impairs heat transfer, enhances fission gas release and leads to increased pellet-clad interaction (PCI). When fuel has been operating at low power for extended periods, return to power is limited by PCI restrictions. These reduce the ability of nuclear power to load-follow grid demands. We present a r-Ө finite element model for pellet relocation and PCI. It is able to model the opening and closing of cracks between fuel fragments at the pellet waist as well as pellet-bore closure in the case of an annular fuel pellet. The model is able to predict stress concentration ahead of a radial fuel pellet crack as well as the additional radial displacement caused by pellet relocation during periods of reduced power operation.

  1. T.A. Haynes, J.A. Ball, J.H. Shea and M.R. Wenman, Modelling pellet-clad mechanical interaction during extended reduced power operation in bonded nuclear fuel, J. Nuc. Mat., vol. 465, 2015, pp. 280–292
  2. T.A. Haynes, M.R. Wenman, J.A. Ball and J.H. Shea, Finite Modelling of Pellet-Clad Interaction During Operational Transients, Top Fuel Conference Proceedings, Zurich, September 2015