Power control device for nuclear reactor

Purpose: To avoid damage of a fuel can by facilitating the operation of a nuclear reactor and preventing an abrupt increase of the coolant flow rate due to an erroneous operation by the operator or devices. Constitution: When controlling so as to increase the coolant flow rate, a flow rate mode designation signal is applied prior to a flow rate control signal to a mode selector, the output from the selector will operate a control rod blocking device, and will lock the control element. A set request signal is produced with the output, and a heat power limit signal is produced from a heat power limit signal setting unit with a signal produced from a heat power limiting function signal setting unit and the flow rate signal. A setting completion signal is output substantially simultaneously with the signal output from the heat power limit function signal setting unit, and the flow rate increase stopping unit is stopped. On the other hand, when the heat power signal becomes equal to the heat power limit signal, the flow rate increase stopping unit is driven, and the flow rate increase is stopped. (Aizawa, K.)