CONTROL ROD POSITION MONITORING DEVICE

PROBLEM TO BE SOLVED: To provide a control rod position monitoring device enabling continuous position monitoring without damaging a function of an input processing unit by multiplexing signal conversion sections even when a failure is generated in the signal conversion section constituting the input processing unit.SOLUTION: A control rod position monitoring device including a plurality of signal conversion sections 21-V1a to 21-Hnb for converting contact signals A-Vn to A-Hn output from a control rod position detector 10 to control rod position signals comprises: an input processing unit 21 for outputting the control rod position signals to a control rod position signal conversion section 22 and outputting an operating/non-operating state of each signal conversion section to a failure diagnosis section 23; the control rod position signal conversion section 22 for converting the control rod position signals to control rod position information; the failure diagnosis section 23 for performing a failure diagnosis of the signal conversion section based on the operating state signal to output failure diagnosis information to an output processing section 24; and the output processing section 24 to which the control rod position information and the failure diagnosis information is input, and from which the information is output to a control rod position display device 50 and a nuclear reactor control panel 5 via a transmission channel 30a. The signal conversion sections 21-V1a to 21-Hnb are in a multiplex configuration.