Reactor power control apparatus

Abstract

A control apparatus for a boiling water reactor includes a monitoring section for monitoring power distribution in the reactor, a core flow control section for controlling the core flow and an arithmetic operational section for calculating change rate of the linear heat generation rate from the output of the monitoring section to thereby cause the core flow to be increased or decreased through the core flow control section when the calculated change rate exceeds a predetermined limit, whereby the increasing rate of the linear heat generation rate of fuel rods is maintained at a value not greater than the limit value. The power distribution monitoring section serves to generalize the current power distribution in the whole core in trms of typical monitoring quantities at selected locations of in-core neutron detectors. A model of change in the monitoring quantities is prepared from the instant values of the typical monitoring quantities on the basis of calculated sensitivity of the reactor with respect to the load change. With the aid of the model, the monitoring quantities are arithmetically determined with a short period during the power changing operation and are then converted to the power distribution in the whole reactor core.