Analysis of taps fuel performance data to examine the feasibility of extended discharge burnup

Under a programme to assess the performance of fuel elements of Tarapur Atomic Power Station (TAPS) the available data on fuel failure collected during in-core sipping, non-destructive testing at the pool site and post-irradiation examination in hot cells at Trombay have been analysed. The following aspects of fuel performance have been studied: (i) Fuel failure pattern in the core using the cumulative distribution of leakers in the core till the end of sixth cycle. (ii) Fuel failure pattern in the assembly by assessing fuel failure data generated during non-destructive testing of more than 3,000 fuel elements of initial load design. (iii) Burnup dependence of fuel failure by correlating the assembly average burnup with the number of leakers. (iv) Fuel failure mode and other aspects of fuel performance have been studied by detailed hot cell examination of 18 fuel elements of varying burnup in the range 6,000 to 29,000 MWD/MTU. The present paper briefly reviews the current understanding of TAPS fuel performance and the feasibility of extending the fuel discharge burnup. (author)