BEST ESTIMATE ANALYSIS OF PROCESSES IN RBMK FUEL RODS DURING OPERATION CYCLE
In this article the processes in fuel rods ofRBMK-type reactors during operation cycle were analyzedemploying the best estimate methodology. The FEMAXI-6 code was selected for such analysis. At first, the evaluationof the specifics of RBMK fuel rods and the adaptationof the code was provided. Later, the single fuel rod modelof RBMK-1500 was developed and the processes, whichoccur during whole life of fuel assembly inside the core,were analyzed, using adopted FEMAXI-6 code. For thisanalysis the fuel rod from fuel assembly with average initialpower (2.5 MW) was selected.
The uncertainty and sensitivity analysis of the behaviorof cladding stress and gap between fuel pellet andthe cladding were performed using GRS best estimatemethodology by employing SUSA program code. The resultsof the analysis show, that the fuel cladding remainsintact during whole life in normal operation, evaluatingpossible uncertainties of the calculation. The performedanalysis demonstrates a possibility to identify the state offuel rods after the normal operation that is necessary beforethe long-term fuel storage in the spent fuel pools.