Device for monitoring reactor operation

Purpose: To safely operate a reactor by forming an optimum envelope by a simple operation in monitoring the envelope at fuel control operating time. Constitution: A performance computer calculates the reactor core performance upon reception of an input signal from a process input unit. The computer further calculates the tertiary heat output distribution of the reactor core and produces, as a result, a tertiary fuel linear power density distribution data (PLH), a fuel burnup degree data (EXF). These data are transferred and stored in a memory. An envelope computer is started by the controller, and calculates an envelope (PC) from the data (PLH, EXF), the linear power density distribution and burnup degree when completing the fuel control operations at respective steps stored in the controller, and the burnup degree corresponding to the envelope sand feeds them to the memory. A monitor compares the data (PLH) with the data (PC) and produces an alarm or a control signal when the former exceeds the latter. (Yoshihara, H.)