Progress in monitoring and optimisation of thermal performance - Tempo

Enhancements of the TEMPO system for monitoring and optimisation of thermal performance of nuclear steam cycles are described. As described previously, TEMPO is based on first-principles models and work in an optimisation mode, a data reconciliation mode, or a simulation mode. For the data reconciliation (and optimisation) mode the most important enhancement is a parameter-sensitivity analysis feature. The results obtained with TEMPO during an extended test period at Swedish NPP Forsmark are included. The calculated values follow the measured ones closely, also during initial phases of coast-down. Feedwater flow is usually predicted to within 2 kg/s. The goodness of fit usually centered around 0.9, and dropped to zero in cases of known faults. The results are also analysed in terms of redundancy and model configuration, among other things. Monte Carlo simulations indicate that the analytically derived value for the goodness of fit is lower than the true value. The report also discusses briefly how to use the various calculational modes of TEMPO in fault detection, isolation and identification. (Author)