A Transistorized A.C. Carrier Type Shut-Down Amplifier as a Protective Device in Nuclear Power Stations

It is necessary to protect a nuclear reactor against excess flux. The shut-down amplifier or excess flux trip amplifier supplies information to the safety circuit, so as to produce a reactor shut-down when the power exceeds a reference level. The operation is reviewed and the design requirements applicable to shut-down amplifiers are discussed. The three most essential design features of the shut-down amplifier are to give an indication of the difference between the reactor power level and a reference level, to cause a trip when the reactor power equals or exceeds the reference level, and to give a trip on failure of any component or combination of components in the system and absolute reliability of trip action in response to reactor power.