Calculation and assessment of fuel performance parameters at Ukrainian NPPs

Different fuel cycles from different nuclear fuel suppliers are being operated at Ukrainian NPPs. Calculation and assessment of fuel performance is urgent for current and future fuel cycles performance analyzing. The fuel performance assessment at Ukrainian NPPs used to be based on the fuel factor of generating energy. It was calculated as a ratio of the utilized nuclear fuel cost to electricity production during fuel campaign or cycle. That's why the results of the calculations was determined rather by fuel prices than fuel performance. In addition, this parameter includes the fuel price indices, which are confidential. In that case, the Ukrainian nuclear operator decided to develop the fuel performance assessment methodology for common type of the Ukrainian reactors (VVER 1000 MWt). Due to the methodology, the fuel performance is assessed by the fuel utilization performance (FUP). The FUP is the technical-and-economic parameter, which characterizes the efficiency of the fuel utilization for the thermal energy production in the core. It is based on the calculated parameters: the coefficient of the fuel energy potential utilization (FEPU) and the natural uranium rate (NUR). The parameters are calculated for operated fuel cycle and fuel campaign and for planned fuel campaign. The FEPU is a dimensionless coefficient, which is a ratio of produced thermal energy in the core to energetic potential of operated fuel assemblies (FA) during fuel campaign. The energetic potential of the FA is thermal energy, which the FA can produce during operation in achieving the regulate burn up. The NUR is the natural uranium rate for producing thermal energy in the core. The report provides obtained results of the parameters at Ukrainian NPPs. In according to the results the assessment of the FUP was made. (author)