Patent Number: 
Section: abstract

A safety valve drive system is operated such that a safety valve of a nuclear power plant is opened by supplying a driving gas by using a pilot valve at an occurrence of an accident or a transient state to thereby protect a reactor against pressure application. The safety valve drive system is provided with a safety valve drive unit, as a function of actuating the safety valve, and cables. The safety valve drive unit actuates in a manner that the safety valve is opened in response to respective auto-depressurization system actuating signals for two or more segments among respective auto-depressurization system actuating signals for four segments, and is closed if an auto-depressurization system actuating signal for one or less segment among the auto-depressurization system actuating signals for the four segments is received. The cables are connected to the safety valve drive unit and used to transfer the auto-depressurization system actuating signals for the four segments.