JP3050928B2 - Control rod position monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for monitoring the position of a control rod of a power reactor, and more particularly to reducing the burden on an operator for a control rod with a failed reed switch. The present invention relates to a control rod position monitoring device that can easily estimate the position of a control rod in which a reed switch has failed.

[0002]

2. Description of the Related Art Generally, a power generating reactor is provided with nearly 200 control rods, which are pulled out or inserted from the reactor core to control the power of the reactor and adjust the power distribution. Are doing. This control rod is driven by a hydraulic pressure or a magnetic jack or the like to control the position.

The actual insertion or withdrawal of control rods is confirmed by detecting the position of a reed switch that operates when each control rod passes. The reed switches are provided for each control rod, and are provided for about 30 control rods per control rod from the entire withdrawal position to the full insertion position. Usually, any one control rod is selected by an operator to perform a pull-out or insertion operation. This operation is driven by the control rod driving device such that the position of the reed switch is moved backward or forward by one operation. Therefore, if the position of the reed switch does not change during operation, it is expected that the contact failure of the reed switch, the failure of the drive circuit, or the failure of the control rod drive system due to the hydraulic pressure or the magnetic jack. Generally, the drive circuit is provided with a self-diagnosis circuit, and the control rod drive system is provided with a failure detection circuit such as a pressure switch.If no failure is detected by the self-diagnosis circuit or the failure detection circuit, the reed switch itself is used. Is considered to be a failure.

In particular, in the case of a contact failure of the reed switch contact, the control rod position signal becomes non-signal and the current position cannot be determined. Therefore, such a failure must be immediately notified. In this case, the control rod position monitoring device detects which of the control rod reed switches has failed, outputs an alarm, and displays an individual display on the display panel. Conventionally, in this control rod position monitoring device, the alarm output and the individual display on the display panel are continued until the faulty part is recovered, so that the fault recovery work is notified.

Hereinafter, a conventional control rod position monitoring device of this type will be described. FIG. 3 is a block diagram showing an example of the overall configuration of the control rod position monitoring device. In FIG. 3, a number of control rods 2 installed in a nuclear reactor 1 are driven by respective control rod drive systems 3. After the lead switch signals (ON or OFF signals) a of the plurality of reed switches 4A to 4D operating according to the position of one control rod 2 are guided to the reed switch matrix 5A and converted into 11-bit binary signals b Is input to the terminal device 6 and sent to the central monitoring device 7 via the transmission line as a control rod position signal c having an address. Such an operation is sequentially repeated at a constant period for each control rod, and the control rod position signals c for all the control rods are transmitted to the central monitoring device 7.

On the other hand, the central monitoring device 7 displays on all the control rod status indicators 8 and monitors the positions of the control rods. If there is a failure, the individual display lamp 9A on the failure display panel 9 is turned on. Let it. When the operator selects an arbitrary control rod from the control rod selection panel 10 and then selects the insertion or withdrawal function, the control rod selection signal d is set to the central drive unit 1.
The solenoid valve drive signal e having an address is transmitted to the local drive unit 12 via the transmission line. Accordingly, the on-site driving device 12 outputs the solenoid valve driving signal f to drive the corresponding control rod, and the pull-out supply valve 13, the insertion discharge valve 14, the insertion supply valve 1
5. The pull-out / discharge valve 16 is appropriately excited to guide the water supplied from the water pressure unit 17 to the control rod drive system 3 or to discharge the discharge water from the control rod drive system 3 to drive the control rod 2.

FIG. 4 is a block diagram showing a detailed configuration example of the control rod position failure detecting section inside the central monitoring device 7. As shown in FIG. In FIG. 4, the control rod position signal c having the address transmitted from the terminal device 6 is received by the transmission receiving circuit 7A, and is transmitted via the transmission transmitting circuit 7B to the state display signal k.
Is sent to the all control rod status indicator 8 as
It is guided to a position fault detection circuit 7c ₁ ~7c _n. This position failure detection circuit 7c ₁ ~7c _n is provided for each of the control rod 2, and how the reed switch 4A~4D also not operate position to detect such cases unknown position failure detection signal i _1,
i ₂ ,... are output. The position failure detection signals i ₁ , i ₂ ,... Of the control rods 2 are output by OR (logical sum) output.
It is output to the failure display panel 9 as a failure display signal.
Further, the position failure detection signals i ₁ , i ₂ ,... Are transmitted to position failure transfer circuits 7D _{1 to} 7D provided for each control rod 2.
_Entered in _n . This position failure transfer circuit 7D ₁ ~7D _n
Means that when the position failure detection signals i ₁ , i ₂ ,.
The control rod position signal c is converted into position failure display signals j ₁ , j ₂ ,
... is output to the failure display output circuit 7E. And
The position failure display signals j ₁ , j ₂ ,... Of the control rods 2 input to the failure display output circuit 7E are output to the failure display panel 9 as position failure display signals m.

As described above, in the control rod position monitoring device described above, the reed switches 4A to 4D for detecting the control rod position are provided.
If 4D fails for any reason, reed switch 4
The failure display panel 9 can grasp the failure occurrence position or the current state of the position failure signal of the control rod 2 in which A to 4D has failed.

However, such a control rod position monitoring device has the following problems. That is, since the operation of the reactor is performed by comprehensively monitoring various parameters including the position of the control rod 2, even if one reed switch 4 of one control rod 2 fails, usually, Control rod 2
Can be operated to check the current position based on the information of the front and rear reed switches 4. However, when it is very important to confirm that all the control rods 2 are in the full insertion positions, as in the case of a scrum, in particular, the reed switch 4 in the full insertion position for confirming the full insertion of one control rod 2 is used. In the event of a failure, it is not possible to confirm that all the control rods have been fully inserted, and furthermore, it is not possible to perform the insertion / removal operation of the control rods 2 as in the case of a scrum. In a situation where the position cannot be confirmed, there has been no means for confirming the current position.

[0010] Therefore, in the above situation,
In the control rod position monitoring device described above, the operator is obliged to perform the operation of inserting the relevant control rod, such as re-scramming, selecting the relevant control rod to perform single rod scram, and urgently inserting the relevant control rod. Has been
There was a problem that the burden on the operator was large. In addition, even if the above operation is performed, there is no guarantee that the corresponding control rod is at the entire insertion position, and the current position cannot be estimated. Therefore, when the relevant control rod is actually stopped at the intermediate withdrawal position. However, there is a problem that the necessary measures cannot be performed appropriately and promptly.

[0011]

As described above, in the conventional control rod position monitoring device, not only is the operator burden on the control rod in which the reed switch fails, but also the control in which the reed switch fails. There was a problem that the position of the rod could not be estimated.

An object of the present invention is to reduce the burden on the operator for a control rod having a failed reed switch, and to easily estimate the position of the control rod having a failed reed switch. An object of the present invention is to provide a highly reliable control rod position monitoring device.

[0013]

In order to achieve the above object, according to the present invention, a plurality of control rods are provided corresponding to a plurality of control rods disposed in a nuclear reactor, respectively, for detecting a position of the control rod. A reed switch, a terminal device that inputs signals from each reed switch, and transmits a position signal of each control rod at regular intervals, and a position signal of each control rod from the terminal device, and inputs the position signal of each control rod. In a control rod position monitoring device comprising a central monitoring device that monitors a position state, detects a failure, and displays the failure on a display means, inputs a position signal of each control rod transmitted from the terminal device at regular intervals, A control rod position failure detection circuit that detects each control rod position failure and outputs a position failure detection signal, and a memory that continuously updates and stores a plurality of control rod position signals sent from the terminal device at regular intervals. Circuit and control rod position When a position failure detection signal is detected from the failure detection circuit, multiple consecutive position data including the time of the failure of the failed control rod are retrieved from the memory circuit and displayed as the position history of the failed control rod. And a failure display circuit for displaying the means in the central monitoring device.

[0014]

Therefore, in the control rod position monitoring device of the present invention, the position signal of each control rod transmitted from the terminal device at regular intervals is updated and stored in the memory circuit continuously plural times, and the position failure detection signal is output. When it is detected, a plurality of consecutive position data including the time of occurrence of the failure of the control rod in which the failure has occurred is taken out from the memory circuit and displayed as the position history of the control rod in which the position failure has occurred. As a result, it is possible to estimate the current position from the position information of the control rods before and after the occurrence of the abnormality, thereby reducing the burden on the control rods in which the reed switch has failed and the operator's burden. The position of the control rod can be easily estimated.

[0015]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of a central monitoring device in a control rod position monitoring device according to the present invention. The same parts as those in FIG. Only the different parts will be described. In addition,
Since the entire configuration of the control rod position monitoring device is the same as that of the conventional device shown in FIG. 3, the description thereof is also omitted.

That is, as shown in FIG. 1, the central monitoring device 7 of the present embodiment uses the position fault transfer circuit 7D shown in FIG.
_{1 to} 7D _n are omitted, and each control rod position signal c ₁ , c ₂ ,... Transmitted from the terminal device 6 at regular intervals and received by the transmission receiving circuit 7A is repeated a plurality of times. It has a configuration in which a memory circuit 7F ₁ ~7F _n to update stored. FIG. 2 shows the memory circuits 7F _{1 to} 7F _n (in the figure,
Is a circuit diagram showing a detailed configuration example of showing only a memory circuit 7F _1).

As shown in FIG. 2, the present memory circuit 7F
_1, when the position failure detection signal i ₁ is ON, the control rod position fault point and k, a counter circuit 7F ₁₁ for outputting a position storage permission signal p after k + 2 times the input, the output signal p of the counter circuit 7F ₁₁ Is OFF, the control rod position signal c ₁
The b Con switcher 7F be transferred to the stack memory 7F _13
12, when the position failure detection signal i ₁ is ON, n times stored in the stack memory 7F ₁₃ (k-2, k-
1, k, k + 1, k + 2 several consecutive position data)
Controlling the rod position signal, and a con of switcher 7F ₁₄ to be transferred to the fault display circuit 7E as a position fault indication signal j _1, it is configured by providing for each control rod 2.

[0019] With this configuration, the storage control rod position signal c ₁ always several times, taking out the position data of the control rod failure of the reed switch is generated from the stack memory 7F _13, displays the n times of position history can do. Next, the operation of the control rod position monitoring device of the present embodiment configured as described above will be described.

[0020] Now, for example, when a failure to read the switch 4A of the reactor 1 has occurred, the control rod position signal c ₁ having an address is inputted to the central monitoring unit 7 without position data, the position fault corresponding to the address the detection circuit 7c _1, are detected failure of the position signal, the position fault detection signal i
₁ turns ON. This position failure detection signal i ₁ is turned ON, and the clock counter circuit 7F ₁₁ of the memory circuit 7F ₁ is positioned storage permission signal p after input cycle n ₁ times of the control rod position signal c ₁ is turned ON. Thereby, the switch 7 of the b-con
F ₁₂ is transferred to the stack memory 7F ₁₃ of the control rod position signal c ₁ at this time becomes a stop, stack memory 7F ₁₃
, The signal n ₁ before the occurrence of the failure, the position signal at the time of the occurrence of the failure, and the position signal for the n ₁ times after the occurrence of the failure are all stored.

Further, the position signals stored in the stack memory 7F ₁₃ is located storage permission when a failure occurrence signal p
There By turns ON, the switching unit 7F ₁₄ of a con is transferred to the fault indication circuit 7E operates. Further, the data stored in the stack memory 7F ₁₃ is displayed as a position history for all fault display panel 9, it is notified to the operator. Accordingly, the operator can estimate the position of the control rod 2 based on the position history of the control rod 2 in which the failure of the reed switch 4A has occurred. This is necessary because conventional position estimation is impossible. Scrum by operator,
There is no need to perform an operation such as selecting the corresponding control rod to perform a single rod scram or performing an emergency insertion operation of the corresponding control rod, so that the burden on the operator can be greatly reduced.

As described above, the control rod position monitoring device of this embodiment continuously transmits the control rod position signals c sent from the terminal device 6 at regular intervals a plurality of times to the memory circuits 7F ₁ and 7F.
F ₂ to update stored, when the position failure detection signal i _1, i ₂ are detected, the position data multiple consecutive times including the failure occurrence of failure to the control rod 2, the memory circuit 7F _1, 7F
₂ is displayed on the failure display panel 9 as the position history of the control rod in which the position failure has occurred.

Therefore, since the position history of the control rod 2 in which the failure of the reed switch 4 has occurred can be known, the position of the control rod 2 in which the failure of the reed switch 4 has occurred can be estimated, and the failure of the control rod 2 can be estimated. The operator does not need to perform various operations after the occurrence, so that the burden on the operator can be remarkably reduced as compared with the related art. Further, since the position of the control rod 2 in which the reed switch 4 has failed can be quickly estimated, it is possible to quickly take measures for safety.

In the above-described embodiment, the case where the memory circuit is provided in the central monitoring device has been described. However, the present invention is not limited to this. For example, the present memory circuit may be provided in the on-site terminal device. An effect can be obtained.

[0025]

As described above, according to the present invention, the position signal of each control rod transmitted from the terminal device at regular intervals is updated and stored in the memory circuit a plurality of times in succession, and the position failure detection signal is obtained. When detected, multiple consecutive position data including the time of failure of the failed control rod is retrieved from the memory circuit and displayed as the position history of the failed control rod. It is possible to provide an extremely reliable control rod position monitoring device capable of reducing the burden on an operator for the control rod and reducing the position of the control rod whose reed switch has failed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a control rod position monitoring device according to the present invention.

FIG. 2 is an exemplary block diagram showing an example of the internal configuration of a central monitoring device in the embodiment.

FIG. 3 is a block diagram showing an example of the overall configuration of a control rod position monitoring device.

FIG. 4 is a block diagram showing an example of the internal configuration of a conventional central monitoring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor, 2 ... Control rod, 3 ... Control rod drive system, 4A-4
D: Reed switch, 5A: Reed switch matrix, 6: Terminal device, 7: Central monitoring device, 8: All control rod status display, 9: Fault display panel, 10: Control rod selection panel, 11: Central drive device, 12 ... field drive device, 13 ...
Pull-out supply valve, 14: insertion discharge valve, 15: insertion supply valve, 1
6 ... Pull-out valve, 17 ... Hydraulic unit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G21C 17/10 G21C 17/00 JICST file (JOIS)

Claims (1)

(57) [Claims] A plurality of reed switches provided in correspondence with a plurality of control rods disposed in a nuclear reactor, for detecting positions of the control rods, and receiving signals from the respective reed switches, A terminal device for transmitting a position signal of each control rod at regular intervals, and a position signal of each control rod from the terminal device are inputted, a position state of each control rod is monitored, a failure is detected, and a display means is provided. In a control rod position monitoring device composed of a central monitoring device to display, a position signal of each control rod transmitted from the terminal device at regular intervals is input,
A control rod position failure detection circuit that detects each control rod position failure and outputs a position failure detection signal, and continuously updates and stores a plurality of control rod position signals sent from the terminal device at regular intervals. When a position failure detection signal from the control rod position failure detection circuit is detected from the memory circuit, a plurality of consecutive position data including a time when a failure occurs in the control rod in which the failure has occurred is taken out from the memory circuit, and a position failure detection signal is output. A control rod position monitoring device, comprising: a failure display circuit for displaying the generated control rod position history on the display means in the central monitoring device.