Abnormal state detecting apparatus utilizing control rod for use in nuclear reactor

An abnormal state detecting apparatus utilizing control rods for a nuclear reactor having a nuclear reactor core incorporated therein with a plurality of the control rods and a control rod driving device for driving said control rods in response to operation commands for control rods, comprising;

• control rod position detectors for detecting an inserted position of each control rod;
• a plurality of local output detectors disposed three-dimensionally in the nuclear reactor core for detecting a local output of the nuclear reactor;
• a first comparator for comparing an output of said control rod position detector obtained immediately after the application of said operation command with another output of said control rod position detector obtained at the termination of a predetermined waiting time interval from said application;
• a second comparator for comparing an output of said local output detector obtained immediately after said application with another output of said local output detector obtained at the termination of a predetermined waiting time interval from said application;
• and
• abnormal judging means for determining an abnormal state of the nuclear reactor and location of a fault position in accordance with the magnitude of each of outputs from said first and second comparators.

An abnormal state detecting apparatus utilizing control rods for a nuclear reactor having a nuclear reactor core incorporated therein with a plurality of the control rods and a control rod driving device for driving at least control rods selectively determined in response to a command signal for selecting the control rods, comprising;

• control rod position detectors for detecting an inserted position of each control rod;
• a plurality of local output detectors disposed three-dimensionally in the nuclear reactor core for detecting a local output of the nuclear reactor;
• a first comparator for comparing an output of said control rod position detector obtained immediately after the application of said selecting command with another output of said control rod position detector obtained at the termination of a predetermined waiting time interval from said application;
• a second comparator for comparing an output of said local output detector obtained immediately after said application with an output responsive to outputs of said local output detectors obtained at the termination of a predetermined waiting time interval from said application;
• and
• abnormal judging means for determining an abnormal state of the nuclear reactor and location of a fault position in accordance with the magnitude of each of outputs from said first and second comparators, said output responsive to outputs of said local output detectors being a mean value of outputs of a plurality of local output detectors around the control rod selectively determined by said selecting signal.

An abnormal state detecting apparatus utilizing control rods for a nuclear reactor having a nuclear reactor core incorporated therein with a plurality of the control rods and a control rod driving device for moving selected control rods in an indicated direction by receiving a signal for selecting control rods to be operated and another signal for indicating a direction in which the control rod is moved, comprising;

• a control rod position detector having a magnet provided on a member movable together with the control rod and reed switches provided on fixed positions arranged in an equally spaced manner in the direction of movement of the control rod for producing an output when said magnet approaches to said reed switch;
• a plurality of local output detectors disposed three-dimensionally in the nuclear reactor core for detecting a local output of the nuclear reactor;
• circuit means for averaging outputs of a plurality of local output detectors around a selected control rod in response to the control rod selecting signal;
• first and second memories for respectively memorizing the output of the control rod position detector and that of the averaging circuit means obtained at the time when both the control rod selecting signal and operating direction signal are applied;
• a timer for setting a waiting time interval in response to the operating direction signal and for producing an output at the termination of said waiting time interval;
• estimating means for estimating an output of the position detector at the termination of said waiting time interval by receiving an output of the first memory and the operating direction signal;
• third and fourth memories for respectively memorizing the output of the position detector and that of the averaging circuit means in response to the output of said timer;
• a first comparator means for comparing the output of said estimating means with the output of said third memory;
• a second comparator means for comparing the output of said second memory with the output of said fourth memory;
• and
• abnormal judging means for determining an abnormal state of the nuclear reactor and location of a fault position in accordance with results of comparison by said first and second comparator means.

An apparatus for detecting an abnormal state in a control system for a nuclear reactor having a nuclear reactor core incorporated therein with a plurality of control rods, a control rod driving device for driving a control rod selected in response to an operation command signal including a control rod selection signal, control rod position detectors for detecting respective inserted positions of said control rods, and a plurality of local output detectors arranged three-dimensionally in said nuclear reactor core for detecting local outputs of said nuclear reactor, comprising:

• a first comparator receiving an output of a control rod position detector for a selected control rod obtained immediately after the application of said operation command signal, and receiving another output of said control rod position detector obtained at a time when a predetermined time has elapsed after said application;
• a second comparator receiving an output of a local output detector obtained immediately after said application of said operation command signal, and receiving another output of said local output detector obtained at a time when said predetermined time has elapsed after said application, said local output detector being arranged in the vicinity of said selected control rod;
• and
• fault position detecting means receiving outputs of said first and second comparators for determining the location of a fault position in instruments provided in said nuclear reactor in accordance with the magnitude of each of said outputs of said first and second comparators.