Nuclear reactor control system

Claim 1

In a nuclear reactor including a pressure vessel having a coolant inlet and outlet zone, a core disposed therebetween and from which useful heat is extracted by a coolant fluid, the improvement comprising means for controlling the reactivity level of the core including neutron absorber members moveable in respective guide passages extending with the core, a plurality of flow controllers each disposed within the pressure vessel for communication with a corresponding guide passage, each flow controller being communicated with a source of pressurized fluid and operable in response to reception of a fluidic form trigger signal to communicate the guide passage with the fluid source and thereby establish in the passage a pressurized fluid flow driving the neutron absorber member therein to a given position, and decoder means disposed within the pressure vessel to receive a binary coded command signal presented in fluidic form and identifying a specific neutron absorber member to be moved to such given position, said decoder means being operable in response to the command signal to apply a fluidic form trigger signal to the flow controller associated with the identified neutron absorber member and thereby drive same to said position.