Vapor temperature control device for fast breeder reactor plant

Object: To permit the temperature control system of a fast breeder reactor to efficiently control the fluid temperature at the outlet of the heated side. Structure: A bypass system from the outlet of a secondary system sodium pump to the sodium inlet side of a re-heater is provided, and a flow control valve is provided at an intermediate point in the bypass system. Meanwhile, the control system comprises a system for moving the control rods by means of a subtractor for comparing the output of a vapor temperature detector at the outlet of an over-heater and the output of a temperature setter and a subtractor for producing the set value of the temperature at the outlet of the reactor through a proportional integrator-differentiator from the output of said first-mentioned subtractor and a system for moving a bypass flow control valve by operating said proportional integrator-differentiator controller through a subtractor for comparing the output of the re-heater and the output of the temperature setter. (Yoshino, Y.)