Nuclear reactor pressure control device

Purpose: To perform surveillance test in BWR type reactors without switching the pressure control mode, by synthesizing both of the signals for the reactor pressure and the turbine inlet pressure. Constitution: The device comprises a reactor pressure detector, a turbine inlet pressure detector a signal synthesizing circuit for sunthesizing signals from both of the detectors, and a valve control circuit for controlling the adjusting valve and bypass valve of the turbine on the basis of the synthesized pressure signal. By synthesizing both of the reactor and turbine pressure signal, undesired characteristics such as of promoting the external disturbance and of time delay can be offset to perform the surveillance test without switching the pressure control mode, with no reduction in the reactor pressure and with no unrequired reactor scram, whereby the operation performance of the nuclear power plant can be improved. (Moriyama, K.)