JP2009236710A - Control rod drive controlling device and its drive controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control rod drive controlling device for improving the reliability by simplifying the wiring and assembling work of a control panel by reducing the number of output substrates and reducing the failure rate. <P>SOLUTION: This control rod drive controlling device 10 controls the lifting drive of a nuclear reactor control rod 11. The control rod drive controlling device 10 comprises a control circuit 17 for operating the lifting drive amount of the nuclear reactor control rod 11 according to an operation signal (d) from a control rod operating means 16, a drive signal output circuit 18 for ON/OFF-controlling power supply branch lines 19a-19d based on a control signal (e) from the control circuit 17, a power supply breaking circuit 21 disposed in a power supply line 19 connected to a plurality of power supply branch lines 19a-19d, and control rod drive solenoid valves 13a-13d disposed in the power supply branch lines 19a-19d, respectively. The nuclear reactor control rod 11 is constituted lifting-drivably in a conducting state between the power supply breaking circuit 21 and the drive signal output circuit 18. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a control rod drive control technology for controlling the raising / lowering drive of a control rod of a nuclear power plant, and more particularly, a control rod drive control device including a malfunction prevention means for preventing malfunction of a nuclear reactor control rod and a drive control method thereof. About.

  Generally, the control rod of a boiling water reactor is driven by the water pressure of the control rod drive water, and the reactor control rod is inserted or pulled out depending on the direction in which the water pressure is applied. The direction in which the water pressure of the control rod drive water is applied is performed by applying a drive power source to an electromagnetic valve as a directional control valve forming a pair (see cited reference 1).

  The conventional control rod drive control device 1 is configured as shown in FIG. 6, and one reactor control rod 2 includes a set of four control rod drive solenoid valves 3 (3a, 3b, 3c, 3d). Then, the control rod drive water supply a or the discharge b is performed by opening / closing the control rod drive electromagnetic valves 3a to 3d of each set by the control rod drive control device 1. The insertion or withdrawal position of the nuclear reactor control rod 1 is detected by the position detection probe 4 and monitored as a control rod position signal c.

  On the other hand, the control rod drive control device 1 includes a control rod operation circuit 5, a drive control control circuit 6 for the nuclear reactor control rod 2, and an output board 7 (7a, 7b) between ON / OFF of the power supply 8. Prepare. The control rod drive control device 1 turns on / off the contact of the power branch line to the control rod drive electromagnetic valve 3 based on a control signal e from the control circuit 6 to excite the control rod drive electromagnetic valve 3.

  At this time, the output board 7 (7a, 7b) has a double configuration so that the control rod drive solenoid valve 3 is not excited due to a single failure of the output board 7.

For this reason, two output boards 7 for driving and controlling each set of four control rod drive solenoid valves 3 (3a, 3b, 3c, 3d) are required for one reactor control rod 2. . In the duplex configuration, two output substrates 7 (7a, 7b) are required for each reactor control rod. Since N nuclear reactor control rods 2 are loaded at a standard nuclear power plant, for example, 185 reactors, 2N 370 output boards 7 are required, and the number is very large.
JP-A-63-285491

  In the conventional control rod drive control device 1, the power supply to the control rod drive electromagnetic valve 3 for moving the reactor control rod 2 up and down is ON / OFF controlled by the output board 7 (7 a, 7 b). The output boards 7 (7a, 7b) have a duplex configuration in order to prevent malfunctioning of the reactor control rod 2, and two output boards 7 are required for each reactor control rod 2.

  However, if the output boards 7 (7a, 7b) are of a double configuration, the number of output boards 7 is doubled compared to the normal single configuration of one, and the configuration of the control rod drive control circuit 6 and the control panel Wiring becomes complicated and causes an increase in failure, and the number of parts and cost are excessive, and the assembly work is complicated and takes a long time.

  The present invention has been made in consideration of the above-mentioned circumstances, and has simplified the wiring of the control panel by reducing the number of output boards and the number of parts, and has improved the reliability by reducing the overall failure rate. It is an object of the present invention to provide a rod drive control device and a drive control method thereof.

  Another object of the present invention is to provide a control rod drive control device and a drive control method thereof that can reduce the number of parts, simplify assembly work, reduce assembly work time, and reduce costs. It is in.

  In order to solve the above-described problems, a control rod drive control device according to the present invention is a control rod drive control device that controls the raising / lowering drive of a control rod of a nuclear reactor, in accordance with an operation signal from a control rod operation means. A control circuit for calculating the raising / lowering drive amount of the furnace control rod, a drive signal output circuit for controlling ON / OFF of the power branch line by a control signal from the control circuit, and a power line to which a plurality of power branch lines are connected And a control rod drive solenoid valve provided in each of the power branch lines, and the reactor control rod is driven up and down while the power cutoff circuit and the drive signal output circuit are in a conductive state. It is configured to be possible.

  In addition, the control rod drive control method according to the present invention is the control rod drive control method for controlling the raising / lowering drive of the control rod of the nuclear reactor in order to solve the above-described problem. In this method, an abnormality is determined based on the control rod position signal detected by the rod position detecting means, and when the abnormality is determined, the power line is shut off.

  In the control rod drive control apparatus and drive control method of the present invention, the number of drive signal output circuits (output boards) and the number of parts are greatly reduced to simplify the wiring of the control panel, while reducing the failure rate. Thus, the reliability can be improved, and even if an abnormality occurs in the control circuit or the drive signal output circuit, the malfunction of the reactor control rod can be surely prevented.

  Embodiments of a control rod drive control device and a drive control method thereof according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a configuration diagram showing a first embodiment of a control rod drive control device according to the present invention.

  This control rod drive control device 10 controls the drive of a control rod drive mechanism 12 that drives the control rod 11 of a nuclear power plant to move up and down, and the control rod drive water supplied to the control rod drive mechanism 12 controls the control rod 11. Insertion / extraction is controlled. The insertion and extraction of the reactor control rod 11 is performed by controlling the direction in which the water pressure of the control rod drive water is applied, and the control rod drive solenoid valve 13 (13a, 13b, 13c, 13d) is opened / closed. Operated by control. The insertion or withdrawal position of the reactor control rod 11 is detected by a position detection probe 14 as a position detection means, and is monitored by a control circuit 17 by a control rod position signal c output.

  The control rod drive control device 10 inputs a control rod operation circuit 16 as a control rod operation means, and an operation signal d from the operation circuit 16 and performs various calculations such as a driving amount for raising and lowering the reactor control rod 11. A control circuit 17, an output board 18 for a drive signal output circuit that receives a control signal from the control circuit 17 to turn on / off the contact of the power branch line, and a power branch line 19a by turning on / off the output board 18 To 19a, a set of four control rod drive solenoid valves 13 (13a, 13b, 13c, 13d) and a power shut-off circuit 21 provided on the power line 19 from the power source 20 are provided. A set of four control rod drive solenoid valves 13 is provided corresponding to the reactor control rod 11.

  The power cut-off circuit 21 is provided in a power supply line (main line) 19 that supplies the power supply 20 separately from the output board 18. When the control rods 11 loaded in the reactor core are divided into several divided groups, the power shut-off circuit 21 is used in common for the plurality of grouped control rods 11, so that the plurality of atoms constituting the group One is installed for each furnace control rod 11. Since the contact of the power shutoff circuit 21 is common to a plurality of control rods 11, for example, when 185 nuclear reactor control rods 11 are used in a nuclear power plant and the 185 nuclear reactor control rods 11 are divided into four. 1 uses one power cut-off circuit 22 for about 45 reactor control rods 11. As a whole, only four power cutoff circuits 22 for four circuits need be installed.

  The power shut-off circuit 21 receives a control rod position signal c from the position detection switch 14 which is a control rod position detecting means and an operation signal d from the control rod operation circuit 16 and performs a comparison operation to prevent malfunction. Means 23 are configured.

  The control circuit 17 is configured to perform ON / OFF operation of each output board 18 and also to perform ON / OFF operation of the contacts of the power shut-off circuit 21.

  The reactor control rod 11 is provided with a set of four control rod drive solenoid valves 13 (13a, 13b, 13c, 13d) for each control rod, and the control rod drive solenoid valve 13 is turned ON / OFF. The direction in which the water pressure of the control rod drive water is applied is controlled by an OFF (open / close) operation. Each set of four control rod drive solenoid valves 13 (13a, 13b, 13c, 13d) constitutes a directional solenoid valve, and each set of four control rod drive solenoid valves 13 (13a, 13b, 13c, The reactor control rod 11 is inserted or pulled out by the operation control of 13d).

  Of the four control valves constituting each set of control rod drive solenoid valves 13, two are solenoid valves 13a and 13b for control drive water supply a, and the remaining two are solenoids for control drive water drainage b. They function as valves 13c and 13d, respectively.

  When the reactor control rod 11 is inserted, one electromagnetic valve 13a, 13d is opened and the other electromagnetic valve 13b, 13c is closed, whereby control drive water is supplied to the lower side of the control rod drive mechanism 12 and the upper control The driving water is drained and the reactor control rod 11 is inserted.

  Further, when the nuclear reactor control rod 11 is pulled out, one electromagnetic valve 13a, 13d is closed and the other electromagnetic valve 13b, 13c is opened, thereby supplying control drive water to the upper side of the control rod drive mechanism 12 and lower side. The control drive water is drained and the reactor control rod 11 is pulled out.

  The reactor control rod 11 can be stopped during insertion or withdrawal by performing opening / closing control of a set of four control rod drive solenoid valves 13 (13a, 13b, 13c, 13d).

  In the control rod drive control apparatus 10 of the present embodiment, the output substrate 18 may have a single configuration per reactor control rod 11, so that the total number of output substrates 18 and the duplex configuration are compared. Can be halved. Even if the number of output boards 18 is halved, the power shutoff circuit 21 can be shared by a plurality of control rods 11 constituting a group. For example, when 185 control rods 11 are divided into four groups, However, it is sufficient to use one power cut-off circuit 21 for every about 45 lines, and the number of parts can be greatly reduced. Therefore, the wiring in the control panel can be greatly simplified, and the manufacturing and assembly work of the control panel and the number of man-hours for the test can be reduced, so that the cost can be greatly reduced. Further, since the overall failure rate can be reduced by reducing the number of parts, the reliability can be improved.

[Second Embodiment]
FIG. 2 is a block diagram showing a second embodiment of the control rod drive control device.

  In describing the control rod drive control device 10A of the second embodiment, the same components as those of the control rod drive control device 10 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted or simplified.

  This control rod drive control device 10A provides control circuits 17 and 17 that make a pair of a control rod position signal c from a position detection probe 14 which is a control rod position detection means and an operation signal d from a control rod operation circuit 16. You are typing. The control circuits 17, 17 compare the drive command of the operation signal d from the control rod operation circuit 16 with the drive state of the reactor control rod 11 by the control rod position signal c from the position detection probe 14, and the reactor control rod 11 An abnormality such as a malfunction is detected by the malfunction prevention means 23 constituting the abnormality monitoring means.

  The malfunction prevention means 23 is composed of a pair of control circuits 17 and 17 and a power cutoff circuit 21. The pair of control circuits 17, 17 receives the operation signal d from the control rod operation circuit 16 and the control rod position signal c from the position detection probe 14 and performs a comparison operation. Abnormality such as malfunction is detected. Control signals e and f from the control circuits 17 and 17 are output to the output board 18 and the power shut-off circuit 21. The power shutoff circuit 21 detects the position of the reactor control rod 11 and is turned off by the control circuits 17 and 17 when an abnormality occurs.

  The contact of the power shutoff circuit 21 is normally in an ON (closed) state, and is turned OFF only when the position of the reactor control rod 11 is abnormal. For this reason, the number of ON / OFF operations of the contacts of the power shut-off circuit 21 can be reduced.

  Further, when the control circuits 17 and 17 are abnormal and the control signals e and f are output to both the output board 18 and the power shut-off circuit 21 of the reactor control rod 11, the reactor control of the first embodiment is performed. In many cases, the rod 11 operates, but in this control rod drive control device 10A, the control rod position signal c from the position detection probe 14 can be monitored by the control circuit 17, and the reactor control rod 11 When there is a position abnormality, the contact of the power shutoff circuit 21 is turned off.

  Also in the control rod drive control device 10A of the present embodiment, the number of contact operations of the power shut-off circuit 21 can be reduced, and the number of failure abnormalities such as contact continuity failures can be reduced. When the operation of the reactor control rod 11 is abnormal, the contact of the power shut-off circuit 21 is turned off, so that the malfunctioning position of the reactor control rod 11 can be prevented and the reliability is improved. .

  In this control rod drive control device 10A, the position of the reactor control rod 11 is detected, and when there is an abnormality, the contact of the power shut-off circuit 21 can be turned off, and the malfunction of the reactor control rod 11 is effectively prevented. Can be efficiently prevented.

[Third Embodiment]
FIG. 3 is a block diagram showing a third embodiment of the control rod drive control device.

  In describing the control rod drive control device 10B shown in this embodiment, the same components as those in the control rod drive control device 10 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted or simplified. .

  The control rod drive control device 10B shown in FIG. 3 detects the position signal c of the reactor control rod 11 with the position detection probe 14 of the reactor control rod position detection means, and the position of the control rod from this position detection probe 14 The signal c is input to the monitoring circuit 24 for monitoring, and when there is an abnormality in the position of the nuclear reactor control rod 11, a power cutoff signal (abnormality detection signal) g is output to the power cutoff circuit 21 and the power cutoff circuit 21 Is configured to turn off the contact.

  This control rod drive control device 10B is provided with a pair of monitoring circuits 24, 24 for monitoring the position of the reactor control rod 11 as control rod position monitoring means separately from the control circuits 17, 17, respectively. When the position is abnormal, a configuration is adopted in which the contact of the power shutoff circuit 21 is turned off by the power shutoff signal from the monitoring circuits 24 and 24.

  In the control rod drive control device 10B shown in FIG. 3, the contact of the output substrate 18 is turned ON / OFF by the output signal (control signal) from the control circuit 17 that makes a pair, for driving the reactor control rod 11. At this time, if there is an abnormality in the control circuit 17 or the output board 18, there is a possibility that the contact of the output board 18 is turned ON / OFF in spite of the absence of the operation signal d from the control rod operation circuit 16. There is. In this case, the ON / OFF operation of the contact of the output substrate 18 may cause the nuclear reactor control rod 11 to malfunction.

  For this reason, in this embodiment, the monitoring circuit 24 is provided separately from the control circuit 17, and when there is an abnormality in the position of the reactor control rod 11, the power cutoff circuit 21 is received by the power cutoff signal g from the monitoring circuit 24. ON / OFF operation of the contact. By the contact OFF operation of the power shut-off circuit 21, the monitoring circuit 24 detects an abnormality in the position detection of the reactor control rod 11, and the control circuit 17 does not detect it. For this reason, even if the control circuit 17 itself is abnormal, the driving of the reactor control rod 11 can be stopped.

  In the control rod drive control device 10B of the present embodiment, the monitoring circuit 24 for monitoring the position of the reactor control rod 11 is provided separately from the control circuit 17, so that even when there is an abnormality in the control circuit 17 or the output board 18 Thus, the contact of the power shut-off circuit 21 can be turned off. Therefore, it is possible to reliably prevent malfunction of the nuclear reactor control rod 11 from continuing.

[Fourth Embodiment]
FIG. 4 is a block diagram showing a fourth embodiment of the control rod drive control device.

  In describing the control rod drive control device 10C of the fourth embodiment, the same components as those of the control rod drive control device 10 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted or simplified.

  The control rod drive control device 10C shown in FIG. 4 is provided with a current detection device 26 in the power supply line 19 of the control rod drive electromagnetic valve 13, and a current detection signal h detected by the current detection device 26 is supplied to the current detection circuit 27. A configuration that allows input is adopted. When the current detection signal 27 detects an abnormal current value, the current detection circuit 27 turns off the contact of the power shut-off circuit 21 to control each set of control rod drive solenoid valves 13 (13a, 13b, 13c, 13d). It is the structure which interrupts | blocks the electric current to. The current detection device 26 and the current detection circuit 27 constitute a current monitoring device 28 as current monitoring means. When an abnormal current flows through the power supply line 19 by the current monitoring device 28, the power cutoff circuit 21 is turned off. Has a function to operate.

  In this control rod drive control device 10C, the current detection device 26 constituting the current monitoring device 28 monitors the current in the power supply line 19, and an abnormality in the current supplied to the control rod drive electromagnetic valve 13 is detected by the current detection circuit 27. It is detected by. When the current detection circuit 27 detects an abnormal current value, the contact of the power supply cutoff circuit 21 is turned off to cut off the current.

  In a standard nuclear power plant, there is usually one reactor control rod 11 that is driven at the same time. Therefore, when the control circuit 17 and the output board 18 are normal, the current detected by the current detector 26 is It is below a certain value.

  However, the control rod drive control device 10C has an abnormality in the control circuit 17 and the output board 18, and when a plurality of reactor control rods 11 are driven simultaneously, a current exceeding a certain value in the power supply line 19 is generated. Flowing. The current detection circuit 27 monitors the current of the power supply line 19, and when a current exceeding a certain value flows, the contact of the power shutoff circuit 21 is turned off, and the drive solenoid valve 13 (13a to 13d) of the nuclear reactor control rod 11 is operated. Is interrupted to prevent the reactor control rod 11 from being driven.

  This control rod drive control device 10C detects the position of the reactor control rod 11 with the position detection probe 14, while the power line is used when there is an abnormality in which a plurality of reactor control rods 11 are driven simultaneously. 19 is detected by the current detection device 26, and it is determined by the current detection circuit 27 whether or not the current value exceeds a certain value. When a current exceeding a certain value flows, the current detection circuit 27 operates. Then, the contact of the power cutoff circuit 21 is turned off. By turning off the power shut-off circuit 21, the current to the control rod drive solenoid valve 13 (13a to 13d) is shut off, and the driving of the reactor control rod 11 is blocked.

  In the control rod drive control device 10C of the present embodiment, even when there is an abnormality in the control circuit 17 or the output board 18, the current value of the power supply line 19 is detected by the current detection circuit 27, and a current exceeding a certain value is detected. When the value flows, the power shutoff circuit 21 is turned off by shutting off, so that the current of the control rod drive electromagnetic valve 13 is shut off, and the driving of the reactor control rod 11 is surely prevented.

  Also in this case, the output board 18 may have a single configuration, and it is not necessary to have a duplex configuration. Therefore, the number of output boards 18 can be reduced by half, and the number of parts can be reduced and the cost can be reduced. On the other hand, even if the output board 18 is configured as a single unit, the reactor control rod 11 is prevented from being driven by a malfunction, and when a current of a certain value or more flows through the power supply line 19, the control rod drive solenoid valve 13 (13a-13d) is interrupted, and the driving of the reactor control rod 11 can be reliably prevented.

[Fifth Embodiment]
FIG. 5 is a block diagram showing a fifth embodiment of the control rod drive control device.

  The control rod drive control device 10D of the fifth embodiment is provided with a timer drive device 30 linked to the control rod operation circuit 16 instead of the current monitoring device 28 of the control rod drive control device 10C of the fourth embodiment. Since other configurations and operations are not different from the control rod drive control device 10C of the fourth embodiment, the same components are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  The control rod drive control device 10D shown in FIG. 5 has a timer drive device 30 that is driven by inputting an operation signal i from the control rod operation circuit 16. The timer driving device 30 includes a timer 31 that is excited for a predetermined time by an operation signal i from the control rod operation circuit 16, a relay contact 32 that is turned ON by the excitation of the timer 31, and an ON operation of the relay contact 32. And a relay 33 for energizing the power cutoff circuit 21.

  In this control rod drive control device 10D, the operation signal i from the control rod operation circuit 16 is input to drive the timer drive device 30, and the timer 31 of the timer drive device 30 is excited for a certain time. Due to the excitation of the timer 31, the relay contact 32 is turned ON for a certain time, and the relay 33 is excited. Due to the excitation of the relay 33, the power shut-off circuit 21 is turned on for a certain period of time to be energized, and current is supplied to the control rod drive solenoid valve 13 (13a to 13d).

  After the operation signal i from the control operation circuit 16 disappears, the timer 31 is de-energized after a lapse of a certain time, so that the relay contact 32 is turned off, the relay 33 is demagnetized, and the power cut-off circuit 21 is turned off. Is blocked. For this reason, even when the contact of the output board 18 is erroneously operated due to an abnormality in the control circuit 17 or the output board 18, the control rod drive electromagnetic valve 13 is demagnetized and the driving of the reactor control rod 11 is prevented.

  In the control rod drive control device 10D of the present embodiment, after the control rod operation circuit 16 is operated and a predetermined time elapses, the timer drive device 30 is constant even if the control circuit 17 or the output board 18 has an abnormality. After being driven for a time, the power shut-off circuit 21 is turned off to shut off the current, so that the current to the control rod drive electromagnetic valve 13 is shut off and the driving of the reactor control rod 11 is surely prevented.

  Therefore, even if an abnormality occurs in the control circuit 17 or the output board 18, the malfunction of the reactor control rod 11 is caused by turning on the power shut-off circuit 21 for a certain time after the operation signal i is output from the control rod operation circuit 16. Can be reliably prevented, and the reliability can be improved.

  In this embodiment, not only when there is an abnormality in the control circuit 17 or the output board 18, but also when the reactor control rod 11 performs a normal operation at the time of this abnormality, the malfunction of the reactor control rod 11 is prevented. Thus, the malfunction of the reactor control rod 11 can be prevented.

The block diagram which shows 1st Embodiment of the control-rod drive control apparatus which concerns on this invention. The block diagram which shows 2nd Embodiment of a control-rod drive control apparatus. The block diagram which shows 3rd Embodiment of a control-rod drive control apparatus. The block diagram which shows 4th Embodiment of a control-rod drive control apparatus. The block diagram which shows 5th Embodiment of a control-rod drive control apparatus. The block diagram which shows the conventional control rod drive control apparatus.

Explanation of symbols

10, 10A, 10B, 10C, 10D Control rod drive control device 11 Reactor control rod 12 Control rod drive mechanism 13 (13a-13d) Control rod drive solenoid valve (directional solenoid valve)
14 Position detection probe (control rod position detection means)
16 Control rod operation circuit (control rod operation means)
17 control circuit 18 output means (drive signal output circuit)
19 power line 20 power source 21 power shut-off circuit 23 malfunction prevention means (abnormality monitoring means)
24 Monitoring circuit (control rod position monitoring means)
26 Current detection device 27 Current detection circuit 28 Current monitoring device (current monitoring means)
30 Timer drive unit (timer circuit)
31 Timer 32 Relay contact 33 Relay

Claims (8)

In the control rod drive control device that controls the raising and lowering drive of the control rod of the nuclear reactor,
A control circuit for calculating the lift drive amount of the reactor control rod in response to an operation signal from the control rod operating means;
A drive signal output circuit for ON / OFF control of the power branch line by a control signal from the control circuit;
A power cutoff circuit provided in a power line to which a plurality of power branch lines are connected;
A control rod drive solenoid valve provided in each of the power branch lines,
A control rod drive control device, wherein the power control circuit and the drive signal output circuit are in a conductive state, and the nuclear reactor control rod is configured such that the nuclear reactor control rod can be driven up and down. The control circuit inputs and calculates a control rod position signal from a position detecting means for detecting the raising / lowering position of the reactor control rod,
2. The control rod drive control device according to claim 1, wherein the contact of the power shut-off circuit is ON / OFF controlled. The control rod drive according to claim 2, wherein the power shut-off circuit is normally set in an energized state, and the control rod position signal is set in a shut-off state by a control signal from the control circuit when an abnormality occurs. Control device. 2. The control rod drive control device according to claim 1, further comprising: a monitoring circuit that monitors a raising / lowering position of the reactor control rod, wherein the power cutoff circuit is shut off by an output monitoring signal from the monitoring circuit. Provide a current monitoring device for detecting current in the power line,
2. The control rod drive control device according to claim 1, wherein the current monitoring device detects a flow of an abnormal current in a power line and sets the power cut-off circuit to a cut-off state. 3. A timer driving device is provided that is excited for a predetermined time by an operation signal from the control rod operation circuit,
2. The control rod drive control device according to claim 1, wherein the timer drive device sets the power cut-off circuit to an energized state for a predetermined time after the operation signal is output. In the control rod drive control method for controlling the raising and lowering drive of the control rod of the nuclear reactor,
An abnormality is determined from the operation signal from the control rod operating means and the control rod position signal detected by the control rod position detecting means,
A control rod drive control method characterized by shutting off a power line when an abnormality is determined. In the control rod drive control method for controlling the raising and lowering drive of the control rod of the nuclear reactor,
Detects abnormal current flow in the power line,
A control rod drive control method characterized by shutting off a power supply line when an abnormal current is detected.

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