Optimum Control over the Power of a Load-Following Nuclear Reactor during a Period of Threatened Extreme External Effects

The authors consider a situation where a nuclear power plant operating with a variable daily load schedule receives a signal about the likely start of extreme external influences in the immediate future, forcing the shutdown of the reactor. The plant’s personnel are authorized to establish a regime in which the reactors operate during the period of the threat until it materializes or is canceled. A two-level daily graph is presented of the change in the power of the nuclear reactor. It is assumed a threat warning is received at the beginning of the period, and the reactor power is held constant at a level between day and night regimes for the period of the threat. The problem of finding the optimum level of power is noted and solved. The loss function is calculated as the total economic damage, weighted by the probabilities of the materialization and cancellation of the threat, caused by deviating from the consumption schedule in the event of a false alarm and the downtime in the iodine pit in the event of a real threat. Results show that the effect of optimization grows along with the probability of a threat, so the power regime must be changed to appropriate level a. The effect of optimization is estimated.