JP3514910B2 - Electric drive type control rod soundness confirmation 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 test and control function of a control rod in a nuclear power plant, and more particularly to an electric drive type control rod for confirming the soundness of a holding function of the electric drive type control rod in a fully inserted state. Regarding the soundness confirmation device.

[0002]

2. Description of the Related Art Regarding the operation control of a conventional electric drive type control rod, as shown in the block diagram of FIG. 7, it is driven electrically and hydraulically into a core 2 housed in a reactor pressure vessel 1. A large number of electrically driven control rods 3 which are control rods are installed so that they can be inserted and pulled out.

The electric drive type control rod is inserted and pulled out by an electric drive unit 4 installed outside the reactor pressure vessel 1 and a water pressure control unit 6 via a scram valve 5 which is a water pressure drive unit. It is driven electrically and hydraulically. Further, in the reactor pressure vessel 1, a control rod position detection sensor 7 for detecting the position of the electrically driven control rod 3 which is inserted into and extracted from the core 2 along the axial direction in the vicinity of the electrically driven control rod 3. Is installed.

The electric drive type control rod 3 is driven during normal operation of the nuclear reactor by an electric drive unit 4 which is separably connected to the electric drive type control rod 3 to electrically drive the core 2. The output of the nuclear reactor is controlled by inserting or withdrawing the control rod 3.

At this time, the insertion position of the electrically driven control rod 3 in the core 2 is detected by a position detection means such as a synchro oscillator provided in the electrically driven portion 4, and the control rod position output by this position detection means is detected. From the signal 8, the operator continuously monitors in the central control room or the like.

In the event of a serious nuclear reactor accident such as a main steam pipe rupture, all of the electrically driven control rods 3 are urgently inserted into the core 2 (Scram insertion, hereinafter scram insertion) as reactor scram. It is necessary to suddenly reduce and stabilize the reactor power.

Electric drive type control rod 3 by the electric drive unit
In the insertion operation, the electric drive requires precise control of the reactor power, so that the insertion operation is relatively slow, so that the entire insertion takes time. Therefore, when inserting the scrum, the entire insertion is performed in a short time of, for example, about 3 seconds by hydraulic drive that enables high-speed operation.

The scram insertion of the electrically driven control rod 3 driven by water pressure at the time of the nuclear reactor accident causes the total scrum signal 13 output from the unillustrated nuclear reactor scram board when the accident occurs.
The scram valves 5 are opened simultaneously by a. As a result, the high-pressure water stored in the accumulator in the water pressure control unit 6 flows into the electric drive type control rod 3, so that the electric drive type control rod 3 is located at the lower portion and the connecting portion 4a of the electric drive unit 4 is connected.
After being once separated, the whole is rapidly inserted into the core 2.

The fact that the scram of the electrically driven control rod 3 is inserted within a predetermined time depends on the in-reactor control rod position signal 9 detected by the control rod position detection sensor 7 in the reactor pressure vessel 1. , The control rod switch in the scrum time measurement panel 10
This is performed by the clam time measuring circuit 11.

Further, during the periodic inspection of the nuclear power plant,
It is confirmed that the all-electric drive type control rod 3 is fully inserted without any trouble during the reactor scram. This confirmation test
The operation is performed by sequentially outputting a single scrum signal 13 to each scrum valve 5 from a control rod test device 12 for individually controlling the scram valve 5 at the outlet of the water pressure control unit 6 by an operator.

As a result, one or two electrically driven control rods 3 which have been fully pulled out in advance are replaced by the hydraulic control unit 6.
The scram is inserted by the hydraulic pressure from the scram, and the insertion time of the electric drive type control rod 3 is changed to the control rod scrum time.
In addition to the measurement by the measurement circuit 11, whether or not the operation of the electrically driven control rod 3 is sound is confirmed by checking whether or not this insertion time is a predetermined time.

In the electric drive type control rod 3, as shown in FIG.
As shown in the cross-sectional view of the configuration, when the electric drive type control rod 3 is rapidly inserted into the core 2 by the scrum insertion at any time of all the scram of the electric drive type control rod 3 or at the time of a single scrum. Is the electric drive type control rod 3
Is temporarily separated from the connecting portion 4a of the electric drive unit 4, and only the electric drive type control rod 3 is rapidly raised by the scrum water pressure from the water pressure control unit 6 and is fully inserted into the core 2.

The electric drive type control rod 3 separated from the electric drive unit 4 is supported at all insertion positions by the scrum water pressure from the water pressure control unit 6 at the beginning of the insertion, but this scrum water pressure is electrically driven. After the scrum of the die control rod 3 is inserted, the water pressure is reduced in a short time due to the capacity of the water pressure control unit 6 and the like.

However, since the latch mechanism 14 is retained by the catch 15 at all the insertion positions in the electric drive type control rod 3 which is initially raised by the high pressure scrum water pressure, after the latch mechanism 14 operates. The full insertion state is maintained even if the scrum water pressure from the water pressure control unit 6 decreases.

Regarding the electric drive type control rod 3 which is held in the fully inserted state by the latch mechanism 14, the electric drive unit 4 which has previously separated the electric drive type control rod 3 is
Since the full insertion operation is performed by the single scrum signal 13 or the full scrum signal 13a, the coupling portion 4a of the electric drive unit 4 catches up with the electric drive type control rod 3 that is fully inserted.

The holding of the electric drive type control rod 3 in the fully inserted state by the latch mechanism 14 is released by the follow-up of the electric drive unit 4, but at this time, the electric drive type control rod 3 is connected to the electric drive unit 4. Since it is supported by the connection of the above, the full insertion state is continuously maintained.

Therefore, after the latch mechanism 14 is released by the follow-up of the electric drive unit 4, even if the scrum water pressure is reduced or the scrum valve 5 is closed and the scrum water pressure disappears, the electric drive is performed. The mold control rod 3 does not descend due to its own weight and escape from the core 2.

However, if the latch mechanism 14 is defective, even if the electric drive type control rod 3 is fully inserted by the scrum insertion, the scrum water pressure is reduced or eliminated before the electric drive unit 4 is followed up. Then, the electrically driven control rod 3 descends by its own weight and exits from the core 2, and the reactor scram cannot be performed in a short time.

[0019]

In the confirmation test of the scrum insertion in the periodic inspection or the like, whether the latch function is normally operated by holding the electric drive type control rod 3 in the fully inserted state by the latch mechanism 14. The operator confirms the soundness of the electric drive type control rod 3 by, for example, about 2 minutes until the electric drive unit 4 follows up after the scrum is inserted and the electric drive type control rod 3 is reconnected. It was necessary to confirm the mold control rod 3.

However, in the fully inserted state of the electric drive type control rod 3 at the time of inserting the scrum, since the electric drive type control rod 3 is separated from the electric drive unit 4, the position of the control rod from the electric drive unit 4 is separated. Since the signal 8 cannot be obtained, first of all the electrically driven control rods 3 are checked by the in-reactor control rod position signal 9 detected by the control rod position detection sensor 7 to confirm the entire insertion state by the scrum insertion.

After that, the control rod position signal 8 from the electric drive unit 4 indicates that the follow-up by the electric drive unit 4 has been completed and that this fully inserted state has been taken over by the electric drive unit 4.
I was monitoring until I could confirm.

Therefore, in this monitoring work, it is confirmed that all the electrically driven control rods 3 have been completely inserted by the control rod position detection sensor 7, and the control rod position signal from the control rod position detection sensor 7 is transmitted from the control rod position detection sensor 7. It is confirmed that the state of full insertion by 9 continues until it is followed up by the electric drive unit 4, and further, the control rod position signal 8 output from the electric drive unit 4 upon completion of follow-up indicates full insertion. Make sure that.

This confirmation work is often performed by the operator not only during the scrum but also during the periodic inspection because the number of electrically driven control rods 3 is as large as about 205 in a boiling water reactor. There was a problem of burdening

The object of the present invention is to detect the state in which the electric drive type control rod is inserted in the scrum from the position signal related to the electric drive type control rod in the reactor, and to detect the state of the electric drive type control rod together with the latch mechanism. It is an object of the present invention to provide an electric drive type control rod soundness confirmation device which facilitates confirmation of the soundness of the electric power plant and improves the safety of the nuclear power plant and reduces the burden on the operator.

[0025]

In order to achieve the above object, a soundness confirmation device for an electric drive type control rod according to a first aspect of the present invention is an electric drive during normal operation, a hydraulic drive during scram, and an electric drive during scram. An electric drive type control rod provided with a latch mechanism that is separated from the drive unit and holds the fully inserted state,
Full insertion of the electrically driven control rod is detected by a control rod position signal from a control rod position detection sensor that detects the core insertion state of the electrically driven control rod, and a fully inserted signal is output . A control rod position detection sensor signal processing circuit and a control rod switch for measuring the time until the electric drive type control rod is fully inserted.
A clam time measuring circuit , a control rod test device that outputs a single scrum signal for hydraulically scramming one or two electrically driven control rods, a full insertion signal based on the in-reactor control rod position signal, and the single scrum Input the signal and
From the output of the ram signal to the generation of all insertion signals
The first time limit circuit set to a predetermined time, the first time limit
Signal when the output of the circuit and all insertion signals are satisfied at the same time
AND circuit that outputs, and input the output signal of this AND circuit
The latch mechanism is fully inserted into the electrically driven control rod.
The second set to the time from holding to releasing
Of the second time limit circuit is lit by the output of this second time limit circuit
And a latch function determination circuit for determining the soundness of the latch mechanism having an indicator light .

When one or two electric drive type control rods are hydraulically scrammed by a single scrum signal from the control rod test device, the control rod position is detected by the latch mechanism of the electric drive type control rods. With sensor signal processing circuit
From the control rod scrum time measurement circuit and the latch function determination circuit, it is determined whether or not the fully inserted state of the electrically driven control rod is maintained until it is supported by the follow-up of the electrically driven unit, and the latch function is provided together. Check the soundness of the electric drive type control rod.

According to a second aspect of the present invention, there is provided a latch function determination circuit for determining the soundness of a latch mechanism. The soundness confirmation device for an electrically driven control rod is inserted in a hydraulic control unit instead of a single scrum signal. characterized that you use the closure signal of the scram valve. Even if there is a water pressure drop due to the scram valve closing after the scram of the electric drive type control rod and before the scrum water pressure drops, the latch mechanism from the closing of the scrum valve until the electric drive unit follows up and supports the control rod. It is possible to judge the continuation of all insertion states due to.

According to a third aspect of the present invention, there is provided an apparatus for confirming the soundness of an electrically driven control rod, characterized in that the latch function judging circuit is provided with means for indicating soundness of the latching function or soundness and unhealth.

When the sound display means is provided, the sound display means corresponding to the electric drive type control rod, for example, the normal indicator lamp lights when the latch function is sound, and does not light when the sound function is unhealthy. When the soundness and unhealthy display means are provided, when the latch function is sound, for example, the normal indicator light corresponding to the electric drive type control rod is turned on, and the unhealthy display means, for example, the abnormality indicator light is turned on. do not do. However, when the latch function is unhealthy, for example, the normal indicator does not light,
For example, the abnormality indicator light turns on.

According to a fourth aspect of the present invention, there is provided an electric drive type control rod soundness confirmation apparatus according to the first aspect, in which the control rod scrum time measuring circuit and the latch function judging circuit are provided together with the soundness of full insertion holding of the control rod. Equipped with a control rod full insertion retention soundness determination circuit that determines whether the control rod full insertion retention soundness determination circuit is inserted from the control rod scrum time measurement circuit to a full insertion position by hydraulic pressure with a single scrum signal within a specified time. is the type of all the latch function determination signal temporarily held in the latch mechanism to the scram time determination signal and the latch function determination circuit from follow-up by the electric drive unit in all the insertion position is, the two input signals are both When the reference value is satisfied, the scrum insertion function of the electric drive type control rod is determined to be sound and displayed on the display means.

In the soundness confirmation device at the time of periodic inspection,
Based on the results of the scram time measurement by the control rod scrum time measurement circuit and the confirmation of the latch function by the latch function judgment circuit, the control rod full insertion retention soundness judgment circuit indicates the overall soundness related to the scrum insertion of the electric drive type control rod. Check the sex.

According to a fifth aspect of the present invention, there is provided a sound confirmation device for an electric drive type control rod, which is normally operated by electric drive during scram.
Hydraulically driven and separated from the electric drive during scram
Electric drive with a latch mechanism that keeps all inserted states
Type control rod and the core insertion state of the electrically driven control rod
Control rod position signal from the control rod position detection sensor
Signal detects the full insertion of the electric drive type control rod.
Control rod position detection sensor signal processing circuit that outputs signals
And measure the time until the electric drive type control rod is fully inserted.
Control rod scrum time measuring circuit to set and 1 or 2
Single scrum to hydraulically scrub the electric drive type control rod of the
A control rod tester for outputting a signal, and the control rod position in the furnace
Input all the insertion signals and the single scrum signal.
Output and a single scrum signal is output before all insertion signals
A first timed circuit set to a predetermined time until it occurs,
The output of this first timed circuit and all inserted signals are generated simultaneously.
AND circuit that outputs a signal when it rises, this AND circuit
Input the output signal of the, and the latch mechanism is an electric drive type control
The time from when the rod is fully inserted to when it is released
The set second time circuit, the output of this second time circuit
Indicator light that is turned on by the
Displayed by the control rod full insertion position signal output from the step
The latch is equipped with a wipeout circuit that prevents the lamp from turning on.
From the latch function determination circuit that determines the soundness of the mechanism
It is characterized by

When confirming the soundness of the latch function of the electrically driven control rod, the fully inserted state of the electrically driven control rod is released from the electrically driven unit which releases the latch mechanism and follows up the electrically driven control rod. Check directly with all inserted signals. Therefore, since the accuracy of confirming the test end time of the electric drive type control rod can be obtained with high accuracy, the automatic insertion end of the test in the electric drive type control rod and the next electric drive type control rod subsequent to this by the all insertion signal. By starting the test, the continuous test can be automated.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the drawings. In addition, each figure including the above-mentioned conventional technology
Throughout, the same components will be denoted by the same reference numerals and redundant description will be given.
Is omitted. It should be noted that the following description will be made with reference to the drawings corresponding to one electric drive type control rod 3 for easy understanding of the description. The first embodiment relates to claims 1 and 3 , and as shown in the block diagram of FIG. 1, a large number of electrically driven control rods are provided inside a reactor core 2 housed in a reactor pressure vessel 1. 3 can be inserted and pulled out freely.

The electrically driven control rod 3 is electrically driven and hydraulically driven by an electric drive unit 4 provided outside the reactor pressure vessel 1 and a water pressure control unit 6 via a scrum valve 5, respectively. Further, inside the reactor pressure vessel 1, a control rod position for detecting the position of the electrically driven control rod 3 inserted into or pulled out from the core 2 along the axial direction in the vicinity of the electrically driven control rod 3. A detection sensor 7 is installed.

The electric drive type control rod 3 is driven by the electric drive unit 4 connected to the electric drive type control rod 3 during normal operation of the nuclear reactor. Control the furnace power. At this time, the position of the electrically driven control rod 3 is detected by the position detection means such as a synchro oscillator provided in the electrically driven unit 4, and the control rod position signal 8 is used by the operator to continuously control the position. Are watching over.

In the event of a nuclear reactor accident such as a main steam pipe breakage, all the electrically driven control rods 3 are inserted into the core 2 by scram to gradually reduce and stabilize the nuclear reactor output. Since it is urgent to insert the scrum, it is performed by hydraulic drive that enables high-speed operation in a short time of, for example, about 3 seconds.

Confirmation that the scrum insertion of the electrically driven control rod 3 is performed within a predetermined time is performed by the in-reactor control rod position signal 9 output from the control rod position detection sensor 7 in the reactor pressure vessel 1. Thus, the control rod scrum time measuring circuit 11 having a circuit for detecting the full insertion of the electric drive type control rod 3 is carried out in the soundness confirmation device 16 installed for each electric drive type control rod 3.

In addition, from the control rod position signal 9 in the furnace output from the control rod position detection sensor 7, the state of full insertion of control rods is detected.
A control rod position detection sensor signal processing circuit 17 for outputting a full insertion signal 18 is provided in the preceding stage of the control rod scrum time measuring circuit 11.

Further, the total insertion signal 18 from the control rod position detection sensor signal processing circuit 17 and the single scrum signal 13 output from the control rod testing device 12 for the soundness confirmation test performed during the periodic inspection are input. And a latch function determination circuit 19 for confirming whether the electric drive type control rod 3 is fully inserted and held by the latch mechanism 14 (claim 1).

Further, in the soundness confirmation device 16, instead of the single scrum signal 13 for the control rod position detection sensor signal processing circuit 17 and the latch function determination circuit 19, a reactor scrum machine (not shown) is used. It is configured so as to enter the entire scram signal 13a output when the reactor accident.

Next, the operation of the above configuration will be described. The control rod test device 12 is used by an operator to confirm the operation of the electrically driven control rod 3 during the reactor scram and the scram insertion function during the periodic inspection. In this confirmation test, one or two predetermined ones are selected from the electric drive type control rods 3 which are all pulled out in advance, and a single scram valve 5 is inserted into the outlet of each water pressure control unit 6. This is performed by outputting the scrum signal 13.

The hydraulically driven control rods 3 which have been hydraulically scrammed are separated from the connecting portions 4a of the electric driving portions 4 and fully inserted into the core 2 at a rapid rate of, for example, about 3 seconds, so that the latch mechanism 14 is formed. By locking the catch 15, the fully inserted state is maintained. The mechanism and function of the latch mechanism 14 for holding the electric drive type control rod 3 in the fully inserted state are the same as those of the conventional example shown in FIG.

After this, the hydraulic pressure of the scrum decreases or disappears with the passage of time, but the electric drive type control rod 3 is held in the fully inserted state by the latch mechanism 14, and further, by the single scrum signal 13 separately. The follow-up of the operated electric drive unit 4 releases the latch mechanism 14, and the electric drive unit 4 supports the fully inserted state.

If a nuclear reactor accident occurs during the operation of the nuclear reactor, the all-scram signal 13a is output from the reactor scram board (not shown), and the all-electric drive type control rod 3 scrams by the all-scram signal 13a. However, the state after this is the same as the operation by the single scrum signal 13.

In the soundness confirmation device 16, as shown in the logic circuit diagram of FIG.
The control rod position signal 9 from the furnace is input to the control rod position detection sensor signal processing circuit 17. Further, at the time of periodic inspection, a single scrum signal 13 from the control rod test device 12 selected by the operator to one or two electrically driven control rods 3 or all scrums from a reactor scrum machine (not shown) at the time of a reactor accident A signal 13a is output, and this signal is input to the control rod scrum time measuring circuit 11 and the latch function determination circuit 19.

Here, the latch function judging circuit 19 includes a first time limit circuit 20, an AND circuit 21, a second time limit circuit 22, and a third time limit circuit 22.
The time limit circuit 23, the OR circuit 24, the normal indicator light 25 which is a sound display means for the latch function, the reset button 26, etc. (Claim 3) .

AND circuit 21 of the latch function determination circuit 19
In, the electric drive type control rod 3 is fully inserted by the full insertion signal 18 from the control rod position detection sensor signal processing circuit 17 and the scrum water pressure from the water pressure control unit 6, and the full insertion state is the original scrum. A signal is output when the single scrum signal 13 or the entire scrum signal 13a passing through the first time limit circuit 20 corresponding to the time supported by the water pressure (for example, 2 seconds) is simultaneously established.

The output signal of the AND circuit 21 is such that the initial water pressure from the water pressure control unit 6 is lowered and the latch mechanism is
After the fully inserted state is held by 14, the electric drive unit 4 is followed up by the single scrum signal 13 or the entire scrum signal 13a to support the electrically driven control rod 3 in the fully inserted state and to latch it. Second time to adjust the time until the mechanism 14 is released (in the experiment, the scrum water pressure drops within 90 seconds, so it is set to 90 seconds, for example)
Pass the time circuit 22 of.

Further, a normal indicator lamp is passed through the OR circuit 24.
When it reaches 25, the normal indicator light 25 indicating the soundness of the latch function is turned on. By confirming that the normal indicator light 25 is turned on, the operator can check the latch mechanism 14 and the electrically driven control rod 3
It can be confirmed that all insertion functions of are sound.

In the case of a nuclear reactor accident, the operator confirms that the corresponding normal indicator lamps 25 of all the electrically driven control rods 3 are lit, so that each latch mechanism can be operated.
Together with 14, it is easy to confirm that all the insertion functions of the electrically driven control rod 3 are sound. At this time, the electric drive unit 4
When the follow-up is performed, the connecting portion 4a securely supports the electric drive type control rod 3 and maintains the fully inserted state.

As a result, all the insertion signals 18 are established, so that the single scrum signal 13 or all the scrum signals 13
The third timed circuit that is delayed by the time (for example, 120 seconds) from the occurrence of 13a until the electric drive unit 4 follows up.
The signal that has passed through 23, the AND that passes through the second time limit circuit 22
The output signal of the circuit 21 is blocked in the first wipeout circuit 27.

Since the signal for turning on the normal indicator lamp 25 is blocked by the operation of the first wipeout circuit 27, the OR circuit 24 is controlled by the second wipeout circuit 28. A holding circuit is formed so that the normal indicator lamp 25, which has been lit once, is not lit by the operation of the first wipeout circuit 27, and the signal is continued and continuously lit.

It should be noted that the normal indicator lamp 25 which is continuously lit
For turning off the light, the second
With respect to the wipeout circuit 28, a circuit for canceling the self-holding by the reset button 26 is formed. Thereby, the operator knows the soundness of the electric drive type control rod 3 by the latch mechanism 14 at the time of full insertion by turning on the normality indicator light 25 in the soundness confirmation device 16, and after confirming this, the confirmation result As a result, the self-holding is released by the reset button 26 to turn off the normal indicator lamp 25.

The second embodiment relates to claims 2 and 3 , and as shown in the logic circuit diagram of FIG. 3, a soundness confirmation device.
29 is a control rod position detection sensor signal processing circuit for processing the in-reactor control rod position signal 9 from the control rod position detection sensor 7.
17 and a single scrum signal 13 from the control rod tester 12 to measure the scrum time Control rod scrum time
A measurement circuit 11 is provided.

Further, the total insertion signal 18 from the control rod position detection sensor signal processing circuit 17 and the single scrum signal 13
Input function to check the latch function
It is composed of 30 and. The electrically driven control rod 3 provided inside the reactor pressure vessel 1 and the reactor pressure vessel 1
For the electric drive unit 4 and the like installed outside the
The configuration is similar to that of the embodiment.

Regarding the latch function determination circuit 30, the in-core control rod position signal 9 from the control rod position detection sensor 7 is sent to the control rod position detection sensor signal processing circuit 17, and the single scrum from the control rod test device 12 is used. Signal 13 control rod scrub
It is input to the system time measurement circuit 11 and the latch function determination circuit 30.

The latch function determination circuit 30 includes a first time limit circuit 20, a first AND circuit 21, a second time limit circuit 22, and
A third time circuit 23 and a first OR circuit 24, a normal indicator lamp 25 which is a sound display means of a latch function, and a reset button.
Equipped with 26. Further, a second AND circuit 32 to which the full insertion signal 18 and a scrum valve closing signal 31 output from the scram valve of the hydraulic drive unit are input, and the first AND circuit.
The outputs of 21 and the second AND circuit 32 are composed of a second OR circuit 34 and the like which are input via the second time limit circuit 22 and the fourth time limit circuit 33, respectively.

Next, the operation of the above configuration will be described. In the first AND circuit 21 of the latch function determination circuit 30, the electric drive type control rod 3 is fully inserted by the full insertion signal 18 from the control rod position detection sensor signal processing circuit 17 and the scrum water pressure from the water pressure control unit 6. , A signal is output when the single scrum signal 13 that has passed through the first time limit circuit 20 corresponding to the time when the entire insertion state is supported is simultaneously established.

The output signal of the first AND circuit 21 causes the electric drive type control rod 3 held in the fully inserted state by the latch mechanism 14 to be in the fully inserted state by the follow-up of the electric drive unit 4 when the scrum water pressure is lost. The second OR circuit 34 and the first OR circuit pass through the second time limit circuit 22 that is supported and adjusts the time until the latch mechanism 14 is released.
Normal indicator light 25 indicating the soundness of the latch function via 24
Light up.

Further, the scram valve closing signal 31 of the scram valve 5 which supplies scrum water when the electric drive type control rod 3 is inserted into the scram from the water pressure control unit 6 of the water pressure drive unit,
The entire insertion signal 18 from the control rod position detection sensor signal processing circuit 17 is input to the second AND circuit 32.

As a result, when both signals are simultaneously established in the second AND circuit 32, the output signal from the closing of the scrum valve 5 until the electric drive unit 4 follows up to support the electric drive type control rod 3. Time (eg 90 seconds)
The normal indicator lamp 25 indicating the soundness of the latch function is lit via the second OR circuit 34 and the first OR circuit 24 via the second time limit circuit 33 which adjusts only.

Therefore, even if the scram valve 5 of the hydraulic drive unit is closed and the scram water pressure drops before the scrum water pressure in which the electric drive type control rod 3 is inserted into the scrum drops, even if the scram water pressure drops. The electric drive control rod 3 is held by the latch mechanism 14 from the closing until the electric drive unit 4 follows up to support the electric drive control rod 3.
It can be confirmed that all insertion states of are continued.

Therefore, the operator can confirm the lighting of the normal indicator lamp 25 and the soundness of the electrically driven control rod 3 as well as the latch function in the full insertion. In the first wipeout circuit 27, the signal for turning on the normal indicator lamp 25 is blocked by the single scrum signal 13 passing through the third timing circuit 23.

Further, in the first OR circuit 24, a self-holding circuit by the second wipeout circuit 28 is formed to continue the signal for continuously lighting the normal indicator lamp 25. Furthermore, the fact that the normal indicator lamp 25 can be turned off by the reset 26 and the other functions and effects are the same as those of the first embodiment.

The third embodiment relates to claim 3 , and as shown in the logic circuit diagram of FIG. 4, the soundness confirmation device 35 processes the in- reactor control rod position signal 9 from the control rod position detection sensor 7. All inserts and outputs the signal 18 and the control rod position detection sensor signal processing circuit 17, control rods enter a single scram signal 13 from the control rod testing device 12 for measuring the scram time Te
A scrum time measuring circuit 11 is provided.

Further, the total insertion signal 18 from the control rod position detection sensor signal processing circuit 17 and the single scrum signal 13
Alternatively, it comprises a latch function determination circuit 36 for inputting all the scrum signals 13a and confirming the latch function.
Further, the electric drive type control rod 3 and the electric drive unit 4 in the reactor pressure vessel 1 have the same configuration as that of the above-described first embodiment.

Regarding the latch function determination circuit 36, the in-furnace control rod position signal 9 from the control rod position detection sensor 7 is sent to the control rod position detection sensor signal processing circuit 17 and the control rod test device 12 is also operated. One scrum signal 13 control rod
Input to the scrum time measurement circuit 11 and the latch function determination circuit 36.

The latch function judging circuit 36 includes a first time limit circuit 20, a first AND circuit 21, a second time limit circuit 22,
The third time limit circuit 23 and the first OR circuit 24, the normal indicator light 25 which is a sound display means of the latch function, the reset button 26 and the signal from the first AND circuit 21 and the first
Second AND circuit to which the signal from the time limit circuit 20 is input
37, a second OR circuit 38 which is an unhealthy display means of a latch function, an abnormality indicator lamp 39 and the like.

Next, the operation of the above configuration will be described. The confirmation test performed at the time of the periodic inspection is performed by the operator by selecting one or two predetermined ones from the electrically driven control rods 3 which have been completely pulled out by the control rod test device 12 in advance, and then the outlet of each water pressure control unit 6 is selected. A single scrum signal 13 is output to the scrum valve 5 inserted in the.

In the event of a nuclear reactor accident, a nuclear reactor scram signal (not shown) outputs a nuclear reactor scrum signal 13a to the scram valve 5 of the total water pressure control unit 6. This allows
The electrically driven control rods 3 that have been hydraulically scrammed are separated at the joints 4a of the respective electrically driven units 4 to separate them from the core 2
The full insertion state is rapidly inserted therein, and the fully inserted state is maintained by the latch mechanism 14.

In the latch function determination circuit 36, first, similarly to the first embodiment, the first AND circuit 21 and the first OR circuit 24 are used to drive the electrically driven control rod 3 by the latch function.
The normality indicator 25 is turned on by judging the soundness of. next,
Inverting the output signal established by the first AND circuit 21
It is input to the second AND circuit 37 via 40. Therefore,
From the second AND circuit 37, the first AND circuit
The signal is output when the signal output when the latch function from 21 is healthy stops.

When the signal from the second AND circuit 37 is output, the normal indicator lamp 25 is not turned on.
The output signal from the second AND circuit 37 passes through the third wipeout circuit 41 and the second OR circuit 38, and reaches the abnormality indicator lamp 39 indicating the unhealthyness of the latch function. Turn on the light.

As a result, the operator can confirm that the electrically driven control rod 3 having the latch function in the full insertion is unhealthy. The abnormality indicator lamp 39 is the above-mentioned normal indicator lamp.
By using a color different from 25, it is possible to more easily distinguish and confirm soundness and unhealthyness.

At this time, the electric drive unit 4 follows up to support the electric drive type control rod 3 so that the full insertion signal 18 is established. Therefore, the single scrum signal 13 or the full scrum signal 13a is generated. Signal from the third AND circuit 37 for adjusting the time until the electric drive unit 4 follows up the electric drive type control rod 3, and the signal passing through the second AND circuit 37 is changed to the third wipeout circuit. Stop at 41.

Further, since the signal for turning on the abnormality indicator lamp 39 is short in time due to the operation of the third wipeout circuit 41, the second OR circuit 38 self-holds by the fourth wipeout circuit 42. A circuit is formed so that signals are continuous. As for the abnormality indicator lamp 39, after the operator confirms the abnormality of the electric drive type control rod 3, the reset button 26 together with the normal indicator lamp 25 is used to release the self-holding by the fourth wipeout circuit 42. It can be turned off.

The fourth embodiment relates to claim 4 , and as shown in the configuration diagram of FIG. 5, the soundness confirmation device 43 is detected by the control rod position detection sensor 7 provided inside the reactor pressure vessel 1. Control rod scram time measurement provided with a circuit for detecting the full insertion of the electrically driven control rod 3 by the control rod position signal 9 in the furnace
The circuit 11 is provided.

Further, a control rod position detection sensor signal processing circuit 17 for detecting the full insertion of the control rod from the in-furnace control rod position signal 9 is provided in the preceding stage of the control rod scrum time measuring circuit 11, and the control rod position detection is performed. Sensor signal processing circuit 17
A latch function for inputting the full insertion signal 18 from the control rod test device 12 and the single scrum signal 13 from the control rod test device 12 to confirm that the latch mechanism 14 holds the electric drive type control rod 3 in the full insertion state. A judgment circuit 19 is provided.

Further, the control rod scrum time measuring circuit
A control rod that determines the soundness of the full insertion holding of the electrically driven control rod 3 by the latch mechanism 14 from the scrum time determination signal 44 output by 11 and the latch function determination signal 45 output by the latch function determination circuit 19. It is composed of a total insertion holding soundness judgment circuit 46.

Next, the operation of the above configuration will be described. Here, the control rod disc in the soundness confirmation device 43
The configurations of the ram time measuring circuit 11, the control rod position detection sensor signal processing circuit 17, and the latch function determination circuit 19 and their functions are the same as those in the first embodiment described above.

In the soundness confirmation device 43, in the single scrum test conducted during the periodic inspection, the electric drive type control rod 3 is set in the fully pulled out state in advance, and the electric drive type control rod 3 selected by the operator is selected. On the other hand, a single scrum signal 13 is output from the control rod test device 12, and the scram of the electrically driven control rod 3 is inserted by the hydraulic scrum in units of the hydraulic control unit 6.

Therefore, at this time, the control rod scrum time is measured.
From the circuit 11, a scrum time judgment signal that is inserted by hydraulic pressure to all insertion positions by a single scrum signal 13 within a specified time.
44 is output. Also, from the latch function determination circuit 19,
The all-latch function determination signal 45 temporarily held by the latch mechanism 14 is output until the electric drive unit 4 follows up at all the insertion positions.

In the control rod full insertion holding soundness judgment circuit 46, when both of these signals are input and both satisfy the reference value, the scram insertion function of the electric drive type control rod 3 is judged to be sound. At the same time, it is displayed on a display means (not shown) and provided to the operator. As a result, the scram insertion function of the electrically driven control rod 3 can be confirmed with high accuracy and efficiency, and the burden on the operator is also reduced.

The fifth embodiment relates to claim 5 , and as shown in the logic circuit diagram of FIG. 6, the soundness confirmation device 47 processes the in-reactor control rod position signal 9 from the control rod position detection sensor 7. A control rod position detection sensor signal processing circuit 17 and a control rod scrum time measuring circuit 11 for measuring a scrum time by inputting a single scrum signal 13 from a control rod testing device 12 are provided.

Further, the total insertion signal 18 from the control rod position detection sensor signal processing circuit 17 and the control rod test device 12
From the position detecting means such as a synchro oscillator (not shown) provided in the electric drive unit 4, and the control rod full insertion position signal 48 from the electric drive unit 4.
The latch function determination circuit 49 for confirming the fully inserted state of the electrically driven control rod 3 in FIG.

The latch function determination circuit 49 includes a first time limit circuit 20, an AND circuit 21, a second time limit circuit 22 and an OR circuit 24, and a normal indicator lamp 2 which is a sound indication function of the latch function.
5, and further includes a reset button 26, a first wipeout circuit 27 and a second wipeout circuit 28.

In the latch function determination circuit 49, the first wipeout circuit 27 receives the third time limit signal as a blocking signal.
Instead of inputting the scrum signal 13 via circuit 23,
Except that contact control rod fully inserted position signal 48 is inputted, the electric-driven control rods 3 provided inside the reactor pressure vessel 1, and External electric drive unit 4 or the like installed in the reactor pressure vessel 1, The configuration is similar to that of the first embodiment.

The operation of the above configuration is that one or two electrically driven control rods 3 selected by the operator are scram-inserted by the hydraulic drive unit by the single scrum signal 13 from the control rod test device 12. . The electric drive type control rod 3 is temporarily held by the latch mechanism 14, and then the electric drive unit 4 follows up to make a latch mechanism.
Instead of 14, it is supported by the electric drive unit 4.

At this time, the soundness of the electrically driven control rod 3 in the fully inserted state together with the latch function acts in the same manner as in the first embodiment, and the normal indicator lamp 25 is output by the signal output from the AND circuit 21. It can be confirmed by lit. However, in the fifth embodiment, the control rod full insertion position signal 48 output from the electric drive unit 4 causes the second time
A signal for lighting the normal display lamp 25 through the limit circuit 22 first
The wipeout circuit 27 is designed to prevent this.

Therefore, unlike the predetermined time delay based on the generation of the single scrum signal 13 or the total scrum signal 13a in the case of the first embodiment, the electric drive type control in which the scrum is inserted and the full insertion state is performed. Since the position of the rod 3 that is followed up by the electric drive unit 4 is directly measured, it can be surely confirmed.

Furthermore, the generation of the control rod full insertion position signal 48 is used as the end signal of the latch function determination test in the electric drive type control rod 3 in the soundness confirmation test of the electric drive type control rod 3 to be performed next. Used as a start signal. As a result, in the confirmation test of a large number of electric drive type control rods 3 at the time of periodic inspection, continuous tests can be carried out automatically in sequence, so that the work efficiency is high and the burden on the operator can be reduced.

[0092]

As described above, according to the present invention, the test carried out during the periodic inspection or the full insertion function of the electric drive type control rod to be inserted into the scrum during the scram during the operation of the reactor, together with the latch mechanism, is sound and unhealthy. The determination of sex can be easily confirmed by the indicator light. As a result, the reliability of the scram operation in the electrically driven control rod and the safety of the reactor operation are improved, and the burden on the operator involved in the confirmation test is significantly reduced.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of an integrity check device for an electrically driven control rod according to a first embodiment of the present invention.

FIG. 2 is a logic circuit diagram of the soundness confirmation apparatus according to the first embodiment of the present invention.

FIG. 3 is a logic circuit diagram of a soundness confirmation device according to a second embodiment of the present invention.

FIG. 4 is a logic circuit diagram of a soundness confirmation device according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a soundness confirmation device for an electrically driven control rod according to a fourth embodiment of the present invention.

FIG. 6 is a logic circuit diagram of a soundness confirmation device according to a fifth embodiment of the present invention.

FIG. 7 is a block configuration diagram of a conventional scram time measuring device for an electrically driven control rod.

FIG. 8 is a sectional view showing the configuration of a latch mechanism of an electric drive type control rod.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor pressure vessel, 2 ... Reactor core, 3 ... Electric drive type control rod, 4 ... Electric drive part, 4a ... Electric drive part coupling part, 5 ...
Scram valve, 6 ... Water pressure control unit, 7 ... Control rod position detection sensor, 8 ... Control rod position signal, 9 ... In-furnace control rod position signal, 10 ... Scrum time measurement panel, 11 ... When control rod scram
Measurement circuit , 12 ... Control rod test device, 13 ... Single scrum signal, 13a ... All scrum signal, 14 ... Latch mechanism, 15 ... Catch, 16, 29, 35, 43, 47 ... Soundness confirmation device, 17 ... Control rod position detection sensor signal processing circuit, 18 ... All insertion signals,
19, 30, 36, 49 ... Latch function determination circuit, 20 ... First time circuit, 21 ... AND circuit, First AND circuit, 22, 34 ... Second time circuit, 23 ... Third time circuit, 24 ... OR circuit, first OR circuit, 25 ... normal indicator lamp, 26 ... reset button,
27 ... First wipeout circuit, 28 ... Second wipeout circuit, 31 ... Scrum valve closing signal, 32, 37 ... Second AND
Circuits, 33, 38 ... Second OR circuit, 39 ... Abnormality indicator light, 40 ...
Inversion circuit, 41 ... Third wipeout circuit, 42 ... Fourth wipeout circuit, 44 ... Scrum time determination signal, 45 ... Latch function determination signal, 46 ... Control rod full insertion retention soundness determination time
Road , 48 ... Control rod full insertion position signal.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-292286 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G21C 17/10

Claims (5)

(57) [Claims] 1. An electrically driven control rod provided with a latch mechanism that is electrically driven during normal operation and hydraulically driven during scram, and separates from an electrically driven portion during scram to maintain a fully inserted state, and the electrically driven control rod. A control rod position detection sensor signal processing circuit that detects the full insertion of the electrically driven control rods by a control rod position signal from a control rod position detection sensor that detects the core insertion state and outputs a full insertion signal, A control rod scrum time measuring circuit that measures the time until the electric drive type control rod is fully inserted, and a control rod test device that outputs a single scrum signal for hydraulically scramming one or two electric drive type control rods. In the predetermined time from the output of the single scrum signal to the generation of the full insertion signal after inputting the full insertion signal by the control rod position signal in the furnace and the single scrum signal A fixed first time circuit, an AND circuit that outputs a signal when the output of the first time circuit and all insertion signals are satisfied at the same time, the output signal of the AND circuit is input, and the latch mechanism is electrically driven Soundness of the latch mechanism including a second timing circuit set for the time from the holding of the fully inserted state of the control rod to the release thereof, and an indicator lamp lit by the output of the second timing circuit. An electric drive type control rod soundness confirmation device, comprising: 2. A determines latch function determination circuit the soundness of the latch mechanism, according to claim 1, characterized in that you use closure signal scram valve interposed in place hydraulic control unit into a single scram signal The integrity confirmation device for the electrically driven control rod described. 3. The soundness confirmation device for an electrically driven control rod according to claim 1, wherein the latch function determination circuit is provided with a soundness or soundness / unhealth display means for the latch function. 4. A control rod full-insertion retention soundness determination circuit for determining the integrity of the control rod full-insertion retention, together with the control rod scrum time measurement circuit and the latch function determination circuit. Follow decision circuit with the electric drive unit in all the insertion position from the scram time determination signal and the latch function determination circuit is inserted to the fully inserted position hydraulically by a single scram signal within a specified time after the control rod scram time measuring circuit Input all latch function judgment signals that are temporarily held by the latch mechanism until it is up, and if both input signals satisfy the reference value, the scrum insertion function of the electric drive type control rod becomes sound. Judge,
The integrity confirmation device for an electrically driven control rod according to claim 1, wherein the integrity is displayed on a display means. 5. An electrically driven control rod provided with a latch mechanism that is electrically driven during normal operation and hydraulically driven during scram, and is separated from the electrically driven portion during scram to maintain a fully inserted state, and the electrically driven control rod. A control rod position detection sensor signal processing circuit that detects the full insertion of the electrically driven control rods by a control rod position signal from a control rod position detection sensor that detects the core insertion state and outputs a full insertion signal, A control rod scrum time measuring circuit that measures the time until the electric drive type control rod is fully inserted, and a control rod test device that outputs a single scrum signal for hydraulically scramming one or two electric drive type control rods. In the predetermined time from the output of the single scrum signal to the generation of the full insertion signal after inputting the full insertion signal by the control rod position signal in the furnace and the single scrum signal A fixed first time circuit, an AND circuit that outputs a signal when the output of the first time circuit and all insertion signals are satisfied at the same time, the output signal of the AND circuit is input, and the latch mechanism is electrically driven A second time-limit circuit set for the time from when the control rod is fully inserted to when it is released, an indicator light that is turned on by the output of the second time-limit circuit, and position detection means for the electric drive unit. And a latch function determination circuit that determines the soundness of the latch mechanism that includes a wipeout circuit that blocks the lighting of the indicator light by a control rod full insertion position signal output from the electric drive type Control rod soundness confirmation device.