Concept for fast-response actuation facility for passive emergency protection

A new method of acting on the mechanism of spontaneous actuation of an absorbing rod in emergency protection is proposed and described. The method is based on the different temperature expansion of the sensitive element and isolated base during rapid accidental growth of sodium temperature at the exit from the core. The temperature difference appearing gives rise to rapid change of the size of the sensitive element and an increase of its pressure on the holding device – right up to actuation, causing spontaneous insertion of the emergency protection rod into the core. The delay between the temperature of the sodium laving the sensitive element and the temperature of the sensitive element is 1–3 sec depending on its thickness, which indicates the fast response of the method.