Calculation study of the CANDU type fuel performance at extended burnup

In the case of CANDU type fuel there is a necessity to improve the fuel bundle design in order to increase its ability to meet high burnup. Further bundle sub-division and slightly enriched uranium is one possibility. Furthermore, grading the element sizes also minimizes the linear power output of the individual fuel elements, while maximizing the power output of the bundle. Also, there are design changes of the pellet that can improve performance at higher burnups. The purpose of this study was to make a comparison between new fuel concept performance and standard CANDU type fuel performance. The results of the thermo-mechanical behaviour included in this study demonstrate the influence of geometrical and microstructural parameters on the fuel performance. The calculations were performed by means of a probabilistic analysis system developed in INPR. The results of the analysis point out the performances of the new concept and constitute a guideline for future research. (author). 7 refs, 5 figs