Reactor monitoring device

Purpose: To improve the accuracy in the power distribution correction method and enable to accurately recognize the power distribution in the axial direction of a reactor core. Constitution: Detection signals from four neutron detectors axially disposed in each of neutron instrumentation tubes are sent to a signal procession circuit. This circuit calculates a solution for a general 7th order equation corresponding to the fundamental power distribution previously set depending on the condition that each of the power with respect to point at a predetermined distance from the uppermost or the lowermost end of the reactor core, as well as that the primary differentiation coefficient thereof is zero, to thereby calculate the power distribution in the axial direction of the reactor core and display the calculated result on a display unit and send the result to a reactor control system. (Kamimura, M.)