Nuclear reactor shutdown system

摘要

The nuclear reactor shutdown system comprises a temperature sensitive device connected to a magnetic latch of a neutron absorbing mechanism. The temperature sensitive device is disposed in the neutron absorbing mechanism in such a manner that it is exposed to the reactor coolant so that when the reactor coolant temperature rises above a specific level, the temperature sensitive device will cause the magnetic latch to open and allow neutron absorbing material to enter the reactor core. The temperature sensitive device comprises temperature sensitive material which may be a temperature sensitive resistor sometimes referred to as a thermistor. The thermistor is a device wherein its resistivity significantly increases with increase in its temperature such that when its temperature has significantly increased, the current passing through this system substantially decreases. Therefore, when the nuclear reactor coolant temperature rises significantly, the resistivity in the temperature sensitive material significantly increases to the point where little electricity flows through the circuit thereby causing the magnetic field in the magnetic latch to fall to a level at which the magnetic latch opens thereby inserting neutron absorbing material in the reactor core.