Estimates of the Flow Rate of Pure Condensate when Reactor Plant WWER-1200 is Brought to the Minimum Controlled Power Level after the Emergency Protection Triggering

Activation of the emergency protection entails the injection of a boric acid solution into the reactor core to the standstill value, after which the control rods are raised, and then it is possible to obtain permission to start the reactor. The first stage of reaching the minimum controlled power level (MCL) is associated with feeding the pure condensate to the start-up interval at a high injection rate; the second stage is the mixing of the first circuit and then the injection of the pure condensate, but at a low rate. At the same time, the technical guidelines for safe operation indicate that the flow rate of pure condensate in the start-up interval should not exceed the flow rate of pure condensate to compensate for xenon poisoning by more than 10 t/h, and the rate of introducing the positive reactivity should not exceed 0.02 β eff /min. At the same time, it is not entirely clear how to estimate the flow rate of pure condensate in the start-up interval, since there is no equipment on the power unit for measuring the magnitude of xenon poisoning and the rate of reactivity input. This study answer the question of what is the permissible flow rate of pure condensate the operator can use in the start-up interval in the presence of xenon processes.