NUCLEAR REACTOR STOP SYSTEM OPERATION DEVICE

PURPOSE:To check the magnetizing rush current of a solenoid and obtain a device in which the capacity of a stationary power source device is used to a necessary minimum by inserting an oversaturation reactor in an excitation circuit of the solenoid. CONSTITUTION:An oversaturation reactor 2 is inserted in an excitation circuit composed of a stationary uninterruptive constant frequency constant voltage power source 1, contacts 6A1-6A4 of contactors 5A-5D, solenoids 7A1-7A21 of a scram pilot valve and the like. The contacts 3A-3N of an auxiliary relay opened in the abnormal time of a plant correspond to scram signals. When a manual reset switch is operated and contacts 4A, 4B are closed, the contacts 6A1-6A4 of the contactors 5A-5D are closed and at the same time the solenoids 7A1-7A21 are excited. Since at this time the making phase of applied voltage VL is pi/2 by the action of the oversaturation reactor 2, exciting rush current can be suppressed to a minimum.