JP2023113331A - Interlock system, interlock method, and program - Google Patents

Abstract

To provide a system allowed to detect an abnormality of a device and alleviate the abnormality without relying on a determination of an operator.SOLUTION: An interlock system comprises: an abnormality detecting section that detects an abnormality if there is an inconsistency in a state of a control signal for controlling a device with respect to a change of an associated parameter due to an action of the device; a normality diagnosing section that diagnosis the device as normal based on a change of the associated parameter due to an intended operation; and a stopping section that stops the action of the device if an abnormality is detected by the abnormality detecting section and the normality diagnosing section does not diagnose that the device is normal.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an interlock system, an interlock method, and a program for equipment.

In recent years, in order to improve the operating rate of nuclear power plants by shortening the period of periodic inspections, studies are underway to lengthen the operation cycle and introduce OLM (On Line Maintenance). In addition, it is important to avoid unscheduled shutdowns from the viewpoint of improving the operating rate. From the point of view of defense in depth, the current existing plants have room for improvement in their ability to continue operation. Analyzing past cases, there are cases where control rod operation led to reactor trips. At present, it depends on the judgment of the operator to distinguish between normal and abnormal operation of the control rods, and to perform a mitigation operation in the case of an abnormality to normalize the operation of the control rods. Operator decisions may lead to reactor trips.

In Patent Document 1, when a control rod movement is detected in a situation where a control rod drive command is not output from a control rod position control circuit, malfunction of a power supply device is considered to be the cause. , a control that prevents an unexpected reactivity input operation to the reactor even if the power supply system malfunctions by stopping the control rods by turning off the power circuit breaker.

JP-A-2002-333494

There is a demand for control that detects abnormalities in the operation of equipment and mitigates the abnormalities without relying on the judgment of operators.

The present disclosure provides an interlock system, an interlock method, and a program that can solve the above problems.

According to one embodiment of the present disclosure, the interlock system detects an anomaly when the states of control signals controlling the equipment are inconsistent with respect to changes in parameters associated with the operation of the equipment. a detection unit, a normality diagnosis unit for diagnosing normality with respect to a change in the related parameter due to an intended operation, and an abnormality detected by the abnormality detection unit and not diagnosed as normal by the normality diagnosis unit. and a stopping unit for stopping the operation of the device when the device is in use.

According to one embodiment of the present disclosure, the interlocking method comprises detecting an anomaly when the states of control signals controlling said equipment are inconsistent with respect to changes in relevant parameters associated with the operation of said equipment. and the step of diagnosing as normal with respect to the change in the related parameter due to the intended operation, and the step of detecting abnormality is detected as abnormal, and the step of diagnosing as normal does not diagnose normality. and if so, discontinuing operation of the device.

According to one embodiment of the present disclosure, the program causes the computer to detect an abnormality when the states of control signals for controlling the equipment are inconsistent with respect to changes in parameters associated with the operation of the equipment. a step of diagnosing a change in the relevant parameter accompanying the intended operation as normal; and an abnormality detected in the abnormality detecting step, and no normality diagnosis is made in the normality diagnosing step. and if not, stopping operation of the device.

According to the above-described interlock system and interlock method, it is possible to detect an abnormal operation of equipment from related parameters and the like and mitigate the abnormality without depending on the judgment of the operator. As a result, tripping of the nuclear power plant can be prevented and the plant operating rate can be improved.

1 is a schematic diagram of a nuclear power plant according to an embodiment; FIG. FIG. 10 illustrates control logic for an interlock feature of an embodiment; It is a figure which shows an example of the determination flow regarding control-rod operation|movement of embodiment. It is a figure which shows an example of the hardware constitutions of the control system of embodiment.

<Embodiment>
(composition)
The interlock system of the present disclosure will now be described with reference to FIGS. 1-4. FIG. 1 is a schematic diagram of a PWR (Pressurized Water Reactor) type nuclear power plant 100 according to the present embodiment. Nuclear power plant 100 includes a nuclear reactor installation 5 and a control system 40 . The nuclear reactor facility 5 houses the reactor 1, a primary cooling loop 4 through which a primary coolant circulates, a detector 6, a steam generator, a pressurizer, a cooling water pump and the like (not shown). A nuclear reactor 1 is provided with a fuel cluster 2 and a plurality of control rods 3 . A plurality of control rods 3 are moved up and down in the axial direction of the core to control the output of the reactor 1 . A detector 6 provided outside the reactor 1 detects the power range neutron flux output from the reactor 1 . For example, four detectors 6 are provided, and the output value of the output region neutron flux detected by each detector 6 (hereinafter simply referred to as the neutron flux output value) is CH1 to CH4 (FIG. 2 are indicated by Roman numerals in the output regions neutron fluxes 1 to 4 in FIG. Also, in the nuclear reactor facility 5 , the temperature of the primary coolant is measured and output to the control system 40 . The nuclear power plant 100 also includes turbine equipment such as a turbine, a condenser, and a generator, as well as various instruments, controllers, equipment, and the like, but these are not shown.

The control system 40 is a control system for the control rods 3 with an interlock function. The interlock function is a function of detecting abnormal operation of the control rods 3 and mitigating the abnormal operation. The control system 40 has two functions of anomaly diagnosis logic and anomaly mitigation logic. The abnormality diagnosis logic uses the measured values of related parameters measured by the instruments provided in the nuclear power plant 100 and the control signals output by the controller etc. to detect deviations from the "ideal state" of the control rod 3. Diagnose abnormal operation of the control rods by detecting them. The anomaly mitigation logic performs control to mitigate the detected anomaly when an anomaly is detected by the anomaly diagnosis logic. For example, the fault mitigation logic stops operation of control rods 3 to mitigate the fault.

The control system 40 includes a reactor control system instrument rack 10 , a control panel 20 and a control rod drive device 30 . The reactor control system instrument rack 10, the control panel 20, and the control rod drive device 30 are connected so as to be able to communicate with each other. All of these three devices are devices conventionally installed in the nuclear power plant 100 . By adding a new function to each device, a control system for the control rod 3 with an interlock function according to this embodiment is realized. In the following description, functions and configurations related to this embodiment will be described, and descriptions of other functions and configurations included in these devices will be omitted.

Operators can operate the reactor 1 by manually withdrawing/inserting the control rods 3, by manually concentrating/diluting the primary coolant, and selecting the automatic control mode for the control rods 3. , an automatic replenishment mode for automatically replenishing the primary coolant can be selected. In any of these manual controls and automatic controls, some operation by the operator is input through the control panel 20 or the like. It can be identified which mode is selected and what control is being implemented. A control signal indicating which control mode is selected is configured to be input to the reactor control system instrument rack 10 .

(Reactor control system instrument rack)
The nuclear reactor control system instrument rack 10 collects measured values measured by the instruments, and controls the operation of equipment provided in the nuclear plant 100 based on the collected measured values. The reactor control system instrument rack 10 has a signal acquisition section 11 , a normality diagnosis section 12 , and an abnormality detection section 13 .
The signal acquisition unit 11 acquires various measurement values and control signals. For example, the signal acquisition unit 11 includes four output values of the neutron flux CH1 to 4 detected by the detector 6, the measured value of the primary coolant temperature, the control mode of the control rod 3, etc. (automatic control or manual control, further A control signal indicating the withdrawal or insertion of the control rod 3), a control signal indicating the control mode of concentration/dilution of the primary coolant (automatic control, manual control, execution of emergency concentration operation, etc.). The reactor control system instrument rack 10 generates a control rod control signal based on the measured value of the temperature of the primary coolant acquired by the signal acquisition unit 11 .

The normality diagnosis unit 12 diagnoses that the change in the neutron flux output value (related parameter) due to manual operation by the operator is normal. For example, when an operator manually operates the control rods 3 or concentrates/dilutes the primary coolant, even if there is a change in the output value of the neutron flux, the normal diagnosis unit 12 detects that change. Diagnose as normal, resulting from an intended operation. If the control signal indicating the operator's manual operation is not acquired, the normality diagnosis unit 12 does not diagnose normality. When diagnosing normality, the normality diagnosis unit 12 outputs an interlock block signal to the control rod drive device 30 .

The abnormality detection unit 13 determines whether the state of the control signal (control rod control deviation signal) for the control rods 3 is inconsistent with the change in the neutron flux output value (related parameter) accompanying the operation of the control rods 3. is determined, and an abnormal operation of the control rod 3 is detected when there is a contradiction. For example, when the control rod control deviation signal is in a state in which withdrawal control of the control rods 3 occurs (for example, in a state where the current temperature of the primary coolant is lower than the reference temperature by a predetermined value or more), the output value of the neutron flux is , the abnormality detector 13 determines that the operation of the control rod 3 is normal. Conversely, if the control rod control deviation signal changes the output value of the neutron flux in accordance with the withdrawal operation of the control rods 3 in a state where the withdrawal control of the control rods 3 does not occur, the abnormality detection unit 13 It is determined that the operation of the control rod 3 is abnormal. When an abnormality is determined, the abnormality detection section 13 outputs an interlock signal requesting the stop of the control rods 3 to the control rod driving device 30 .

(control panel)
The control panel 20 includes a screen for displaying the plant status and alarms, and an operating interface such as an operating device for operators to operate. The control panel 20 includes an input section 21 and an output section 22 .
The input unit 21 includes input devices such as switches (reset switch 211, control rod stop switch 212, etc. in FIG. 2), buttons, keyboards, and touch panels, and receives operations of these input devices by the operator. For example, the input unit 21 can be operated by an operator to instruct the operation of withdrawing, inserting, and stopping the control rods 3, concentrating and diluting the primary coolant, setting an automatic control mode for the control of the control rods 3, Accepts an operation to set the automatic replenishment mode for the coolant. Further, the input unit 21 receives an operation (pressing of the reset switch 211) by the operator to instruct resetting. With the reset instruction, it is possible to reset the interlock signal output from the abnormality detection unit 13 and reset the stop instruction of the control rods 3 operated by the operator (pressing of the control rod stop switch 212). For example, when the interlock signal is reset, the interlock signal becomes invalid, and when the control rod 3 stop instruction is reset, the stop instruction becomes invalid.
The output unit 22 generates a signal corresponding to the operation received by the input unit 21 and outputs the signal to the reactor control system instrument rack 10 and the control rod drive device 30 . For example, when a reset operation is performed, the output unit 22 generates and outputs a reset signal. When an operation instructing the stop of the control rods 3 is performed, a stop signal is generated and output.

(Control rod drive device)
A control rod drive 30 controls the operation of the control rods 3 . The control rod drive device 30 includes a signal acquisition section 31 , a stop section 32 and a control section 33 .
The signal acquisition unit 31 acquires various signals from the reactor control system instrument rack 10 and the control panel 20 . For example, the signal acquisition unit 31 receives from the reactor control system instrument rack 10 a control rod automatic withdrawal signal or a control rod manual withdrawal signal instructing the withdrawal of the control rod 3, or a control rod automatic insertion signal instructing the insertion of the control rod 3. and control rod manual insertion signals. For example, the signal acquisition unit 31 acquires the interlock block signal output by the normality diagnosis unit 12 and the interlock signal output by the abnormality detection unit 13 . Further, for example, the signal acquisition unit 31 acquires a stop signal and a reset signal that instruct the control rods 3 to stop.

The stopping unit 32 determines whether or not to stop the operation of the control rods 3 based on the diagnosis result by the normality diagnosis unit 12 acquired by the signal acquisition unit 31 and the determination result by the abnormality detection unit 13 . Specifically, the stop section 32 is operated when the abnormality detection section 13 determines that the control rod 3 is operating abnormally and outputs an interlock signal, and when the normality diagnosis section 12 does not make a normal diagnosis (interlock If no block signal is output), it is determined that the operation of the control rods 3 should be stopped; otherwise, it is determined that the operation of the control rods 3 should not be stopped. When the signal acquisition unit 31 acquires the interlock signal and the reset signal, the stopping unit 32 resets and invalidates the interlock signal based on the reset signal. Thereby, even when the interlock signal is output, the stopping unit 32 determines not to stop the operation of the control rods 3 .

Based on the control rod automatic withdrawal signal, the control rod automatic insertion signal, the control rod manual withdrawal signal, and the control rod manual insertion signal acquired by the signal acquisition unit 31 and the determination result of the stop unit 32, the control unit 33 operates the control rods 3 controls the behavior of For example, when the stopping unit 32 determines not to stop the operation of the control rods 3, the control unit 33 extracts the control rods 3 based on the automatic or manual control rod withdrawal signal acquired by the signal acquiring unit 31. take action. For example, even when the signal acquisition unit 31 acquires the control rod automatic withdrawal signal, the control unit 33 performs the withdrawal operation of the control rods 3 when the stop unit 32 determines to stop the operation of the control rods 3. do not Further, the control unit 33 stops the operation of the control rods 3 when the signal acquisition unit 31 acquires the stop signal.

Next, with reference to FIG. 2, the control logic of the control rods 3 will be described in detail, focusing on the interlock function according to this embodiment. The control system 40 has an abnormality diagnosis logic and an abnormality mitigation logic, and the abnormality diagnosis logic can be further classified into an abnormality detection logic 130 and a normal operation diagnosis logic 120 . The abnormality detection logic is executed by the abnormality detection section 13 and the normal operation diagnosis logic is executed by the normality diagnosis section 12 . Also, the abnormality mitigation logic 320 is mainly executed by the stopping unit 32 . The function of each logic can be described as follows.

(Anomaly detection logic)
The anomaly detection logic is for continuous control rod malfunction (event in which control rod withdrawal/insertion occurs even though there is no control rod withdrawal/insertion signal), control rod mismatch (control rod slip, control rod drop) is intended to detect Calculate the change rate of the neutron flux output value by incomplete differentiation, and confirm that the calculated change rate exceeds the threshold value and that the control rod control deviation signal to the extent that the control rods should operate has not been transmitted. Send an interlock signal as a condition.

(Normal operation diagnosis logic)
Control rod manual operation, dilution/enrichment operation, and emergency enrichment operation can be cited as operations that cause a change in the output of the reactor 1 (a change in the neutron flux output value) regardless of the control rod control deviation signal. It is operated by the member arbitrarily. Therefore, it can be detected that the operation is normal based on the operation device, the position of the switch, and the like. In the normal operation diagnostic logic, after detection of manual operation, transmission of the detection signal is continued until reactivity due to the operation is generated to compensate for the delay, and the flip-flop (circuit 124) is established. As a result, an interlock block signal indicating that the change in the output of the reactor 1 is normal operation is transmitted to block the operation of the interlock. The interlock block signal is stopped when the output change rate falls below the set value.

(Abnormal mitigation logic)
The automatic operation of the control rods is stopped on condition that the interlock signal is output and the interlock block signal is not transmitted. This function can be arbitrarily reset by a control rod automatic withdrawal/insertion stop reset switch (reset switch 211), and reset has priority. In addition, for an event with an output change rate that is too small to be detected by the abnormality detection logic, the control rod stop switch 212 allows the operator to arbitrarily stop the automatic and manual operation of the control rods.

Next, referring to FIG. 2, the configuration and operation of each logic will be described.
<Anomaly detection logic>
The abnormality detection unit 13 has circuits 131, 132, 133a, 133b, 133c, 133d, 134a, 134c, 136a, 136b, and 138, and executes the abnormality detection logic 130 using these circuits.

(Processing 1A)
The circuit 131 of the anomaly detection unit 13 acquires the detected values of the neutron fluxes CH1 to CH4 through the signal acquisition unit 11, performs incomplete differentiation on each, and calculates the rate of change. Subsequently, the circuit 132 of the anomaly detection unit 13 selects the second largest value from among the rates of change of the neutron fluxes CH1-CH4. The reason why the second largest value is selected instead of the largest value is to exclude the influence of an abnormal value due to a channel failure or the like. The circuit 133a of the abnormality detection unit 13 determines whether or not the degree of increase in the second largest rate of change is equal to or greater than the threshold. Determine whether to continue. This eliminates the possibility of a temporary increase in the rate of change due to noise or the like. When the control rod 3 is pulled out, the detected neutron flux increases. If the degree of increase in the detected value of neutron flux is greater than or equal to the threshold, it is considered that the control rod 3 has been pulled out. In other words, the abnormality detection unit 13 uses the output values (related parameters) of the neutron fluxes CH1 to CH4 to detect that the control rod 3 is being pulled out. The circuit 133a of the abnormality detection unit 13 issues a signal 135a when it detects that the control rod 3 is being pulled out, and issues a signal 135a when it does not detect that the control rod 3 is being pulled out. do not.

(Processing 1B)
In parallel with processing 1A, the circuit 133b of the abnormality detection unit 13 acquires the control rod control deviation signal through the signal acquisition unit 11, and the acquired control rod control deviation signal indicates the state in which the withdrawal control of the control rods 3 occurs. determine whether The reactivity in the reactor 1 and the temperature of the primary coolant change by inserting and withdrawing the control rods 3 . The control rod control deviation signal is a signal relating to the deviation between the reference temperature of the primary coolant temperature and the current average temperature. When the deviation is large, the control rods 3 are operated, and when the deviation is small, the control rods 3 are controlled so as not to operate. Therefore, the control state of the control rods 3 can be detected from the control rod control deviation signal. The circuit 133b of the abnormality detection unit 13 detects when the state of the control rod control deviation signal causes withdrawal control of the control rods 3 (for example, when the current primary coolant temperature is lower than the reference temperature and the deviation is greater than the threshold ), otherwise the signal 134 is not output. Next, the circuit 134a of the abnormality detection unit 13 performs an operation opposite to the presence or absence of the output signal based on the determination of the circuit 133b (134a is a NOT circuit, and the same applies hereinafter). That is, the circuit 134a of the abnormality detection unit 13 does not output the signal 135b when the state of the control rod control deviation signal causes withdrawal control of the control rods 3, and outputs the signal 135b when it does not cause withdrawal control. Output.

(Processing 1C)
Next, when the circuit 136a of the abnormality detection unit 13 receives both the signal 135a output as a result of the process 1A and the signal 135b output as a result of the process 1B (136a is an AND circuit, the same applies hereinafter), it outputs the signal 137a. Output. That is, as a result of processing 1A, it is detected that the control rod 3 is being pulled out, and as a result of processing 1B, it is determined that the control rod control deviation signal is not in a state that causes withdrawal control. If so, the circuit 136a of the abnormality detection unit 13 outputs a signal 137a.

(Processing 1D)
The circuit 133c of the abnormality detection unit 13 determines whether the degree of decrease of the second largest value of the rate of change selected by the processing of the circuit 132 is equal to or greater than the threshold. It is determined whether or not the above state continues for a predetermined time or longer. When the control rods 3 are inserted, the detected value of the neutron flux decreases, and if the degree of decrease in the rate of change is equal to or greater than the threshold, it is considered that the control rods 3 have been inserted. The circuit 133c of the abnormality detection unit 13 detects that the control rod 3 is being inserted using the output values of the neutron fluxes CH1-CH4. The circuit 133c of the abnormality detection unit 13 issues a signal 135c when it detects that the insertion motion of the control rods 3 has occurred, and issues a signal 135c when it does not detect that the insertion motion of the control rods 3 has occurred. do not.

(Processing 1E)
In parallel with the processing 1D, the circuit 133d of the abnormality detection unit 13 acquires the control rod control deviation signal, and determines whether the acquired control rod control deviation signal causes insertion control of the control rods 3 (for example, Determine if the current primary coolant temperature is higher than the reference temperature and its deviation is greater than the threshold). The circuit 133d of the abnormality detection section 13 outputs the signal 134b when the control rod control deviation signal is in a state of causing the insertion control of the control rod 3, and does not output the signal 134b otherwise. Next, the circuit 134c of the abnormality detection unit 13 performs an operation opposite to the presence or absence of the output signal based on the determination of the circuit 133d. That is, the circuit 134c of the abnormality detection unit 13 does not output the signal 135d when the state of the control rod control deviation signal causes the insertion control of the control rods 3, and outputs the signal 135d when the insertion control does not occur. Output.

(Processing 1F)
Next, when the circuit 136b of the abnormality detection unit 13 receives both the signal 135c output as a result of the process 1D and the signal 135d output as a result of the process 1E, it outputs a signal 137b. That is, when it is detected that the control rod 3 is being inserted by the processing 1D, and it is determined by the processing 1E from the control rod control deviation signal that the control rod 3 is not being controlled to be inserted. If so, the abnormality detection unit 13 outputs the signal 137b.

(Processing 1G)
Next, when the circuit 138 of the abnormality detection unit 13 receives either the signal 137a output as a result of the process 1C or the signal 137b output as a result of the process 1F (the circuit 138 is an OR circuit, the same applies hereinafter), an abnormality A detection signal 139 is output. In other words, when the withdrawal operation of the control rods 3 is detected from the change in the output value of the neutron fluxes CH1 to CH4, but the withdrawal control of the control rods 3 is not detected from the control rod control deviation signal, or An abnormality is detected when the insertion control of the control rod 3 is not detected from the control rod control deviation signal although the insertion operation of the control rod 3 is detected from the change in the output value of the neutron flux CH1-4. The unit 13 outputs an abnormality detection signal (139). The abnormality detection signal 139 is output to the control rod drive device 30 as the interlock signal 139 .

<Normal operation diagnosis logic>
The normal diagnosis unit 12 performs the following processing (normal operation diagnosis logic 120) based on the information about the operation and control mode of the control rods 3 and the primary coolant acquired through the signal acquisition unit 11. The normal diagnosis section 12 has circuits 121 , 122 , 123 and 124 .

(Processing 2A)
The circuit 121 of the normality diagnosis unit 12 determines whether or not the emergency concentration line flow rate has increased by a threshold value or more, and if it is a threshold value or more, determines whether or not the threshold value or more continues for a predetermined time or longer. The emergency concentration line flow rate rises when the process of injecting high-concentration boric acid water into the core is carried out, and this increase in flow rate means that operators are intentionally adding boric acid. do. In other words, the circuit 121 of the normality diagnosis section 12 detects that the reactivity of the reactor 1 is intentionally changed by the operator through the processing 2A. In such a situation, the detected value of the neutron flux changes even if the control rod control deviation signal is not in a state in which the control rods 3 are operated. The normal diagnosis unit 12 issues a signal 121a when the emergency concentration line flow rate remains equal to or greater than the threshold for a predetermined time or longer, and otherwise does not issue the signal 121a.

(Processing 2B)
The circuit 122 of the normality diagnosis section 12 issues a signal 122a when the automatic replenishment mode is set and the concentration or dilution operation is being performed at the discretion of the operator. This is a signal indicating that there is no abnormality even if the neutron flux output value changes because the operators are consciously performing the concentration or dilution operation.

(Processing 2C)
The circuit 123 of the normality diagnosis unit 12 issues a signal 123a when it acquires either the control rod manual withdrawal signal or the control rod manual insertion signal. This indicates that the operation of the control rods 3 is not controlled automatically but manually by the operator. In such a case, even if the output value of the neutron flux changes, it is not abnormal. is a signal indicating

(Processing 2D)
When the circuit 124 of the normality diagnosis unit 12 receives any one of the signal 121a output as a result of the process 2A, the signal 122a output as a result of the process 2B, and the signal 123a output as a result of the process 2C, the interlock block Output signal 125 . That is, the circuit 124 outputs the interlock block signal 125 when manual operations (concentration, dilution, manual operation of the control rods 3) are being performed. Circuit 124 then outputs an interlock block signal 125 continuously while these manual manipulations are performed and result in changes in the neutron flux. As will be described later (process 2E), the interlock block signal 125 is continuously output while the neutron flux change rate exceeds a predetermined set value.

(Processing 2E)
Further, the circuit 124 of the normality diagnosis section 12 acquires the second largest rate of change 124a of the neutron flux, and outputs an interlock block signal 125 from when this rate of change 124a starts to fluctuate until it stabilizes. More specifically, if the rate of change in the output value of the neutron flux falls within the range of the rate of change caused by the manual operation until a predetermined time has elapsed since the manual operation was performed, the normal diagnosis unit 12 An interlock block signal 125 is output, and output of the interlock block signal 125 is stopped when the rate of change falls below a predetermined set value. The period during which the interlock block signal 125 is output is the period during which the manual control affects the output value of the neutron flux. During this time, even if the control rod control signal is not in a state that causes the control rods 3 to operate and there is a change in the neutron flux output value, the change is due to manual control. In other words, when operators manually perform enrichment, dilution, and control rod operation, and as long as that operation affects the neutron flux output, the change in neutron flux output is not due to the effects of manual control. , a normal diagnosis signal indicating that the change is normal is output to the control rod drive unit 30 as the interlock block signal 125 .

<Abnormal mitigation logic>
The abnormality mitigation logic 320 is executed by the reset switch 211 (input section 21 ) and its output circuit (output section 22 ) of the control panel 20 and the stop section 32 and control section 33 of the control rod drive device 30 . The stop section 32 has a circuit 321 and the control section 33 has circuits 331 , 332 , 333 , 334 , 335 , 336 and 337 .

The circuit 321 of the stop section 32 acquires the interlock signal and the interlock block signal through the signal acquisition section 31 . Since these signals are not always transmitted, the acquisition status of these two signals is as follows: (a) when interlock signal and interlock block signal are acquired, (b) when only interlock signal is acquired , (c) when only the interlock block signal is obtained, and (d) when neither the interlock signal nor the interlock block signal is obtained. The circuit 321 does not output the signal 322 only when (b) only the interlock signal is acquired, and outputs the signal 322 in the cases of (a), (c), and (d). That is, when (b) only the interlock signal is obtained, the signal 322 is not supplied to the subsequent stage, and in the cases of (a), (c), and (d), the signal 322 is supplied to the subsequent stage. .

When the control rod stop switch 212 is pressed, the control rod stop switch 212 outputs a stop signal 212a. Stop signal 212 a is output to circuit 331 . The circuit 331 does not output the signal 331a while acquiring the stop signal 212a, and outputs the signal 331a when not acquiring the stop signal 212a.

When the reset switch 211 is pressed, a reset signal 211a is output. Reset signal 211 a is output to circuit 321 and circuit 331 . A reset signal means a reset of the interlock signal 139 or the stop signal 212a. For example, the circuit 321 outputs the signal 322 while receiving the reset signal 211a even in the above case (b). (In the above cases (a), (c), and (d), the circuit 321 outputs the signal 322 even if the reset signal 211a is acquired.) Circuit 331 outputs signal 331a even though signal 212a is acquired.

(1) When the control rod 3 is automatically controlled and (a), (c), and (d) above (no reset signal and no stop signal)
If the reset switch 211 is not pressed and (b) is other than acquiring only the interlock signal (cases (a), (c), and (d) above) (the signal 322 is output ), the control rod stop switch 212 is not pressed (the signal 331a is output), and the signal acquisition unit 31 acquires the control rod automatic insertion signal 331b, the AND circuit 332 satisfies the AND condition. , OR circuit 334 , the control unit 33 outputs a control rod insertion command to the control rod 3 . Similarly, when the signal acquisition unit 31 acquires the control rod automatic withdrawal signal 331d under the same conditions, the AND condition is established in the AND circuit 335, and the OR circuit 337 causes the control unit 33 to issue the control rod withdrawal command. is output to the control rod 3. In these cases, the control rods 3 operate based on the control rod insertion command or the control rod withdrawal command.

(2) When the control rod 3 is automatically controlled and only the above (b) interlock signal is acquired (no reset signal and stop signal)
The control rod stop switch 212 is not pressed (the signal 331a is output), the reset switch 211 is not pressed, and the signal acquisition unit 31 receives the control rod automatic insertion signal 331b and (b) the interlock signal. (the signal 322 is not output), the signal 322 is not supplied to the subsequent stage of the circuit 321, the AND condition is not established in the AND circuit 332, and the control rod insertion command is not output. Bar 3 stops. Under the same conditions, when the signal acquisition unit 31 acquires the control rod automatic withdrawal signal 331d instead of the control rod automatic insertion signal 331b, the signal 322 is not supplied to the subsequent stage of the circuit 321. is not established, and the control rod withdrawal command is not output. Therefore, the control rod 3 stops. At this time, when the reset switch 211 is pressed, the reset signal 211a is self-held in the circuit 321 and the interlock is invalidated. In other words, even if the interlock signal 139 is output due to the detection of an abnormality during automatic control of the control rods 3, if the operator confirms that there is no abnormality in the operation of the control rods 3 and presses the reset switch 211, The interlock signal 139 is reset (disabled) and the control rods 3 continue to operate. This reset is released when the input of the interlock signal 139 stops.

(3) When the control rod 3 is manually controlled When the signal acquisition unit 31 acquires the control rod manual insertion signal 331c, the signal 332 is not input to the AND circuit 333, so the control rod stop switch 212 is turned off. If not pressed, the AND condition is established in the AND circuit 333 regardless of the presence or absence of the interlock signal or the interlock block signal (regardless of the presence or absence of the signal 322 output from the circuit 321), and the OR circuit 334 performs control. Unit 33 outputs a control rod insertion command to control rod 3 . Similarly, when the signal acquisition unit 31 acquires the control rod manual withdrawal signal 331e, if the control rod stop switch 212 is not pressed, the AND condition is established in the AND circuit 336, and the OR circuit 337 outputs the control unit 33 outputs a control rod withdrawal command to the control rod 3 .

(4) When the control rod 3 is automatically controlled and there is a reset signal but no stop signal Even in this case, circuit 321 outputs signal 322 and circuit 331 outputs signal 331a. Therefore, when the control rod automatic insertion signal 331b is obtained, the control rod insertion command is output, and when the control rod automatic withdrawal signal 331d is obtained, the control rod withdrawal command is output.

(5) The control rod 3 is under automatic control or manual control, and the reset switch is not pressed, and the control rod stop switch is pressed. does not output In this case, the AND condition is not established in the AND circuit 332 even if the control rod automatic insertion signal 331b is acquired, and the AND condition is not established in the AND circuit 333 even if the control rod manual insertion signal 331c is acquired. Similarly, even if the control rod automatic withdrawal signal 331d is acquired, the AND condition is not established in the AND circuit 335, and even if the control rod manual withdrawal signal 331e is acquired, the AND condition is not established in the AND circuit 336. When the control rod stop switch 212 is pressed in this way, the control rods 3 are stopped without outputting a control rod withdrawal command or a control rod insertion command regardless of automatic or manual operation.

(6) When the control rod 3 is under automatic control or manual control, the reset switch is pressed, and the control rod stop switch is pressed. It is also effective for resetting the stop signal 212a output by pressing the control rod stop switch 212. FIG. If the reset switch 211 is pressed when the control rod stop switch 212 is pressed, the stop signal 212a is invalidated and the circuit 331 outputs a signal 331a. Then, in the AND circuits 332 to 336, it is determined whether or not the AND condition is established depending on the acquisition state of the other signals described above, and based on the determination result, a control rod withdrawal command and a control rod insertion command are output. be done. For example, assume that the operator mistakenly presses the control rod stop switch 212 while the control rod automatic insertion signal 331b is being issued. Then, the signal 331a is not supplied to the subsequent stage of the circuit 331, and the control rod 3 stops. After that, when the operator notices the error and presses the reset switch 211, the signal 331a is supplied to the subsequent stage of the circuit 331 while the reset switch 211 is being pressed, and the AND condition is established in the AND circuit 332, and the control is performed. A control rod insertion command is output to the rod 3, and the control rod 3 is inserted.

<Judgment flow>
Next, with reference to FIG. 3, operation determination processing for the control rods 3 will be described.
An abnormality detection unit 13 detects an abnormality of the control rod 3 based on whether the state of the control signal (control rod control deviation signal) is inconsistent with respect to the change in the related parameter (neutron flux output value). (Step S1). The normality diagnosing unit 12 performs a normality diagnosis for the change in the related parameter based on whether or not an operation intended to cause the change has been performed (step S2). The order of step S1 and step S2 may be reversed. Next, the stopping unit 32 determines whether or not abnormality is detected in step S1 and normality is diagnosed in step S2 (step S3). If an abnormality is detected in step S1 and normal diagnosis is not made in step S2 (step S3; Yes), the stopping unit 32 determines whether a reset signal for the interlock signal has been input (step S4). If the reset signal has not been input (step S4; No), the stopping unit 32 determines to stop the operation of the control rods 3 (step S5). If the reset signal has been input (step S4; Yes), the stopping unit 32 determines not to stop the operation of the control rods 3 (step S8).

Further, if no abnormality is detected in step S1, or if it is diagnosed as normal in step S2, the determination in step S3 is No. It is determined whether or not (step S6). If the stop signal has not been input (step S6; No), the controller 33 determines not to stop the operation of the control rods 3 (step S8).

If the stop signal has been input (step S6; Yes), the stopping unit 32 determines whether a reset signal for the stop signal has been input (step S7). If the reset signal has not been input (step S7; No), the stopping unit 32 determines to stop the operation of the control rods 3 (step S5). If the reset signal has been input (step S7; Yes), the stopping unit 32 determines not to stop the operation of the control rods 3 (step S8).

As described above, according to the present embodiment, continuous malfunctions, control rod slips, and drop during automatic control of the control rods 3 can be quickly prevented based on the change rate of the neutron flux output value and the control rod control deviation signal. , and the operation of the control rod 3 can be automatically stopped. As a result, the abnormal operation of the control rods 3 can be judged without depending on the operator's judgment, and the mitigation control can be promptly performed, thereby preventing the nuclear plant 100 from tripping. In addition, by blocking the interlock signal when there is a manual operation by the operator, it is possible to prevent the operation of the control rods 3 from being erroneously stopped. Even if the change rate of the neutron flux output value is small and the abnormality cannot be detected by the abnormality detection logic, the operator can stop the operation of the control rods 3 by operating the control rod stop switch 212. be able to. Even if the interlock signal is output, the operation of the control rods 3 can be continued by operating the reset switch 211 if the operator can confirm that no abnormality has occurred. .

FIG. 4 is a diagram showing an example of the hardware configuration of the control system 40 of the embodiment.
A computer 900 includes a CPU 901 , a main memory device 902 , an auxiliary memory device 903 , an input/output interface 904 and a communication interface 905 . The reactor control system instrument rack 10 , control panel 20 , and control rod drive device 30 described above are implemented in the computer 900 . Each function described above is stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads out the program from the auxiliary storage device 903, develops it in the main storage device 902, and executes the above processing according to the program. Also, the CPU 901 secures a storage area in the main storage device 902 according to the program. In addition, the CPU 901 secures a storage area for storing data being processed in the auxiliary storage device 903 according to the program.

A program for implementing all or part of the functions of the reactor control system instrument rack 10, the control panel 20, and the control rod drive unit 30 is recorded on a computer-readable recording medium, and the program recorded on this recording medium. may be read into a computer system and executed by each functional unit. The "computer system" here includes hardware such as an OS and peripheral devices. The "computer system" also includes the home page providing environment (or display environment) if the WWW system is used. The term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, and storage devices such as hard disks incorporated in computer systems. Moreover, when this program is delivered to the computer 900 via a communication line, the computer 900 receiving the delivery may develop the program in the main storage device 902 and execute the above process. Further, the program may be for realizing part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system. .

Although several embodiments of the present disclosure have been described above, all these embodiments are provided by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

<Appendix>
The interlock system, interlock method and program described in each embodiment are understood as follows, for example.

(1) The interlock system (control system 40) according to the first aspect provides control for controlling the equipment (control rod 3) in response to changes in related parameters (neutron flux output values) associated with the operation of the equipment. When the state of the signal (deviation signal for control rod control) is inconsistent, the abnormality detection unit 13 that detects abnormality and the intended operation (manual operation of concentrating and diluting the control rod 3 and primary coolant) A normality diagnosing unit 12 for diagnosing normality with respect to changes in the related parameters, and an operation of the device when the abnormality is detected by the abnormality detecting unit and the normality diagnosis is not made by the normality diagnosing unit. and a stop portion 32 for stopping.
As a result, the abnormal operation of the equipment can be determined from the relevant parameters without depending on the operator's judgment, and the abnormality can be alleviated.

(2) An interlock system according to a second aspect is the interlock system according to (1), wherein the abnormality detection unit responds to the control signal in which the rate of change of the related parameter should be within a threshold range. Then, when the rate of change is out of the range of the threshold value, an abnormality of the device is detected.
As a result, it is possible to detect a contradiction in the state of the control signal with respect to changes in parameters associated with the operation of the device, and to detect an abnormality.

(3) An interlock system according to a third aspect is the interlock system of (1) to (2), wherein the abnormality detection section calculates the rate of change of the related parameter by incomplete differentiation.
In complete differentiation, the signal disappears and the rate of change of the related parameter cannot be calculated, but incomplete differentiation allows the rate of change to be calculated by leaving the signal.

(4) An interlock system according to a fourth aspect is the interlock system of (1) to (3), wherein the normality diagnosis unit performs the operation until a predetermined time has elapsed after the intended operation is performed. diagnoses as normal when the rate of change of the relevant parameter falls within the range of the rate of change caused by the intended operation, and stops the diagnosis of normality when the rate of change falls below a preset value .
As a result, the period in which the manual operation is performed and the related parameters are affected can be diagnosed as normal and the interlock can be prevented.

(5) An interlock system according to a fifth aspect is the interlock system according to (1) to (4), wherein the stopping unit includes detection of abnormality by the abnormality detection unit and confirmation of normality by the normality diagnosis unit. Irrespective of the diagnosis, based on the operator's instruction, output a signal to stop the equipment.
An operator can stop the operation of the control rods 3 by operating the control rod stop switch 212 . This allows the operator to stop the operation of the control rods 3 even if the change in the neutron flux output value is so small that the interlock signal is not output.

(6) The interlock system according to the sixth aspect is the interlock system of (1) to (5), wherein the stop unit is detected as abnormal by the abnormality detection unit, and the normal diagnosis unit If the normal diagnosis is not made in the above, the stop of the operation of the equipment is cancelled, based on the operator's instruction.
An operator can reset the interlock signal by operating the reset switch 211 . As a result, for example, even if an interlock signal is output, the operation of the control rods 3 can be continued as long as the normality can be confirmed.

(7) The interlock system according to the seventh aspect is the interlock system of (1) to (6), wherein the device is a control rod of a nuclear reactor, and the related parameter is the neutron flux output value and the control signal is a control rod control deviation signal.
This enables detection and mitigation control of abnormal operation of the control rods 3 .

(8) The interlock system according to the eighth aspect is the interlock system of (1) to (7), wherein the abnormality detection unit outputs an interlock signal when detecting an abnormality, and the normality diagnosis unit outputs an interlock block signal when it is diagnosed as normal, and the stopping unit receives the interlock signal and stops the operation of the device when it does not receive the interlock block signal.
This enables detection and mitigation control of abnormal operation of the control rods 3 .

(9) The interlock method according to the ninth aspect includes the step of detecting an abnormality when a state of a control signal for controlling the equipment is inconsistent with respect to changes in parameters associated with the operation of the equipment. a case where an abnormality is detected in the step of diagnosing normality and the step of detecting abnormality with respect to a change in the relevant parameter due to the intended operation, and a normality is not diagnosed in the step of diagnosing normality; and terminating operation of the device.

(10) The program according to the tenth aspect instructs the computer to detect an abnormality when the states of the control signals for controlling the equipment are inconsistent with respect to changes in parameters associated with the operation of the equipment. and the step of diagnosing as normal with respect to the change in the related parameter due to the intended operation, and the step of detecting abnormality is detected as abnormal, and the step of diagnosing as normal does not diagnose normality. and if so, stopping the operation of the device.

DESCRIPTION OF SYMBOLS 1... Reactor, 2... Fuel cluster, 3... Control rod, 4... Primary cooling loop, 5... Reactor equipment, 6... Detector, 10... Reactor Control system instrument rack 11 Signal acquisition unit 12 Normal diagnosis unit 13 Abnormality detection unit 20 Control panel 21 Input unit 22 Output unit 30... Control rod drive device, 31... Signal acquisition unit, 32... Stop unit, 33... Control unit, 40... Control system, 100... Nuclear power plant, 900... Computer , 901 ... CPU, 902 ... main storage device, 903 ... auxiliary storage device, 904 ... input/output interface, 905 ... communication interface

Claims (10)

an anomaly detection unit that detects an anomaly when a state of a control signal for controlling the device is inconsistent with respect to changes in parameters associated with the operation of the device;
a normal diagnosis unit for diagnosing a change in the relevant parameter associated with an intended operation as normal;
a stopping unit that stops the operation of the device when the abnormality detection unit detects an abnormality and the normality diagnosis unit does not diagnose the device as normal;
interlock system with The abnormality detection unit detects an abnormality of the device when the rate of change of the related parameter is outside the range of the threshold with respect to the control signal that should be within the range of the threshold. The interlock system of claim 1. The abnormality detection unit obtains the rate of change of the related parameter by incomplete differentiation,
An interlock system according to claim 1 or claim 2. The normal diagnosis unit diagnoses the apparatus as normal if the rate of change of the related parameter falls within the range of the rate of change caused by the intended operation until a predetermined time has elapsed since the intended operation was performed. , stopping the diagnosis of normality when the rate of change falls below a preset value;
An interlock system according to any one of claims 1 to 3. The stopping unit outputs a signal to stop the device based on an operator's instruction, regardless of detection of abnormality by the abnormality detection unit and normality diagnosis by the normality diagnosis unit.
An interlock system according to any one of claims 1 to 4. When the abnormality detection unit detects an abnormality and the normality diagnosis unit does not diagnose the device as normal, the stop unit stops the operation of the device based on an operator's instruction.
An interlock system according to any one of claims 1 to 5. The device is a control rod of a nuclear reactor, the relevant parameter is the rate of change of the neutron flux output value, and the control signal is a control rod control deviation signal.
An interlock system according to any one of claims 1 to 6. When the abnormality detection unit detects an abnormality, it outputs an interlock signal,
The normality diagnosis unit outputs an interlock block signal when diagnosing normality,
The stopping unit receives the interlock signal and stops the operation of the device when not receiving the interlock block signal.
An interlock system according to any one of claims 1 to 7. Detecting an abnormality when the state of a control signal for controlling the device is inconsistent with respect to changes in parameters associated with the operation of the device;
diagnosing as normal a change in the relevant parameter associated with the intended operation;
a step of stopping the operation of the device when an abnormality is detected in the abnormality detection step and the normality diagnosis is not made in the normality diagnosis step;
interlocking method with to the computer,
Detecting an abnormality when the state of a control signal for controlling the device is inconsistent with respect to changes in parameters associated with the operation of the device;
diagnosing as normal a change in the relevant parameter associated with the intended operation;
a step of stopping the operation of the device when an abnormality is detected in the abnormality detection step and the normality diagnosis is not made in the normality diagnosis step;
program to run.

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