Device for monitoring and conditioning reactor safety

Purpose: To maintain the reactor safety rapidly and surely with a simple structure by providing a plurality of neutron detectors in the reactor core and selecting only a predetermined frequency band by the use of a band path filter circuit to judge the reactor safety. Constitution: The reactor core in the pressure vessel of a nuclear reactor is provided with a plurality of neutron detectors, the output signal of which are inputted into a band path filter circuit adapted to select and amplify only those signals within a predetermined frequency band. The band path filter circuit is constituted such that the passing filter band contains resonance frequency (0.2 - 1 Hz) concerning the thermo-hydrodynamic stability in each of the fuel channels of the reactor. The reactor power can be reduced by the insertion of those control rods only for the regions showing unstable tendency in the reactor core, whereby the reactor safety can be ensured. (Moriyama, K.)