Differential probabilistic space-temporal model for real-time power prognosis in failures in a nuclear reactor

The aim of this paper is the neutronic flux prognosis in a nuclear reactor for faults in the measurement of local power range monitors (LPRMs) in real time using differential probabilistic space-temporal model (DPSTM). The LPRMs provide inputs to the average power range monitor (APRM). The LPRM houses a fission chamber and their associated signal cables. The failure of one or more chains of LPRMs is common during the operational cycle. The circuit averages only LPRM signals that are operational and the output from the averaging circuit for each APRM channel is the route to the process computer. The DPSTM allows a reliable reconstruction in real time signal of those LPRMs that are out of order. The DPSTM is evaluated in terms of predictive accuracy for different time horizons and compared to a time series. The DPSTM based prognosis methodology was developed and validated with real signals of Ringhals stability benchmarks.