Reactor operation monitoring device

Purpose: To rapidly and easily monitor a BWR type reactor core with high accuracy. Constitution: This device consists of a comparator for comparing the reading of a local neutron detecting system (LPRM) with a reading corresponding to a PC envelope (a threshold value determined in fuel power density), a process computer, and a control rod drive. The comparator discriminates the reading corresponding the PC envelope stored in a memory with the reading of the LPRM. If the difference therebetween is higher than a predetermined reference, the comparator produces an output to an output device and feeds a signal to the control rod driver, which thereupon pulls out the control rod. Meanwhile, if the difference falls within the reference, the process computer executes the reactor core power distribution repetition calculation and compares the calculated result of the power density over the total fuel assemble with the PC envelope. (Kamimura, M.)