[en] Under a programme to assess the performance of fuel elements of Tarapur Atomic Power Station, post-irradiation examination has been carried out on some elements. The examination has revealed two modes of fuel element failure - stress corrosion cracking and internal hydriding. Nodular corrosion was observed to be severe in the initial load fuel elements, while it was not significant in the reload fuel elements. Fretting corrosion was observed at spacer grid locations in the initial load fuel elements. Available data collected by non-destructive testing of more than 3,800 initial load fuel elements from 109 defective fuel assemblies have been analysed. The regions of fuel assembly having high failure rates have been identified. (author)