JPS63163196A - Moving type in-pile instrumentation system detector drive and usage thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a mobile reactor core for calibrating a power range neutron east detector for in-core neutron east monitoring of a nuclear reactor such as a boiling water reactor. The present invention relates to internal instrumentation systems, and particularly to a detector drive device for a mobile core 81 instrumentation system and a method of using the same.

(Prior art) A nuclear reactor such as a boiling water reactor is equipped with a power range neutron detector (hereinafter referred to as an LPPM detector) in its core to monitor the neutron flux within the reactor. A mobile in-core instrumentation system (Trave) is used to calibrate the RM detector.
rsina Incore Probe 5vs-te
l, hereinafter referred to as TIP. ) will be installed.

The conventional IP1 is configured as shown in Fig. 4,
A reactor pressure vessel 3 housed within the reactor containment vessel 2 is supported on a support pedestal 4 and surrounded by a heat shielding wall 5. A plurality of power range detector assemblies 6 are installed inside the reactor pressure vessel 3, and the TI
A P detector comparison jL tube 7 is accommodated.

TIP 1 includes the above-mentioned calibration tube 7, an indexing device 8 installed outside the reactor pressure vessel support pedestal 4, a valve assembly 9 installed outside the reactor containment vessel 2, and a shielding vessel 1.
0, a detector driving device 11, and guide tubes 12a, 12b, etc. that interconnect these. Guide tube 12
The number of a and 12b is from the detector drive device 11 to the index device 8.
There is one guide tube up to the end, and there are a plurality of guide tubes, for example ten, from the exit side of the indexing device 8, and a plurality of output area detector aggregates 6 correspond to the ten guide tubes 12b, respectively.

A drive cable (not shown) is guided so as to be inserted into the guide tube 128.12b, and a mobile in-core instrumentation system detector (sen 9) is attached to the tip of this drive cable. Which power range detector assembly 6 this drive couple is inserted into is determined by switching the indexing device 8 .

The inner peripheral surfaces of the guide tubes 12a, 12b are coated with dry lubricant, and the drive cable and the guide tubes 12a, 12 are coated with a dry lubricant.
This is aimed at alleviating the frictional resistance of b.

However, as the coated dry lubricant becomes thinner over time, the drive cable and guide tubes 12a, 12
The frictional resistance with b increases and the drive cable is damaged. Therefore, the frictional resistance between the drive couple and the guide tubes 12a, 12b is periodically monitored by measuring the torque when the drive cable is inserted.

On the other hand, the detector drive device 11 for driving the drive cable has an external appearance similar to that shown in FIG. Side cover 148
A circular window 15 is formed therein, and this circular window 15 is closed with a lid 16.

When measuring the torque of the detector drive device 11, remove the lid 16, insert a Little French 1 into the circular window 15, and set this torque wrench 17 on a drive shaft for taking in and taking out a drive cable (not shown). . After setting, rotate the torque wrench 17 and connect the drive cable to the guide tube 12.
8.12b.

When inserting the drive cable, the numerical value of the torque wrench 17 is read and recorded every fixed insertion distance.

By this torque measurement, the drive cable and guide tubes 12a, 1
2b is monitored.

However, the guide tubes 12a and 12b smell on about 30 sides! It is very long and has many measurement points, so if it relies on manual labor by workers, it will take a long time to complete the measurements.

Furthermore, there is a risk that the friction powder of the dry lubricant coated on the inner circumferential surfaces of the guide tubes 12a and 12b will become radioactive and scatter to the outside through the circular window 15, and there is a concern that workers will be exposed to radiation.

Also, this detector drive device is used to move the drive cable in and out, but since the drive cable receives neutron and gamma ray irradiation in the reactor core, the radiation dose increases, so 1-herc measurement is not possible during reactor operation. I will not do it. For this reason, in nuclear reactors, torque measurement work is carried out only during periodic inspections once a year to determine when to replace the guide tubes, which shortens the replacement cycle of the guide tubes and reduces radioactive waste accordingly. To increase.

(Problems to be Solved by the Invention) In the conventional detector drive device of the mobile in-core instrumentation system, the torque of the drive couple is measured once a year to determine when to replace the guide tube. The guide tube was replaced with a 〒II, which resulted in an increase in radioactive waste, and since the I-Luke measurement was done manually, there was a risk of exposure to radiation during the measurement.

The present invention has been made in consideration of the above-mentioned circumstances, and is a mobile in-core instrumentation system that can reduce radiation exposure of workers, optimize the replacement cycle of guide tubes, and reduce radioactive waste. The object of the present invention is to provide a system detector driving device and a method for using the same.

[Structure of the invention]

(Means to solve the problem) This case No. 1? Detector part #J of the mobile in-core instrumentation system according to the Rth invention, in order to achieve the above-mentioned purpose, the drive cable to which the mobile in-core instrumentation system detector is attached is wound. A take-up reel and a cable drive wJI structure for taking in and out the driving couple wound on the take-up reel are housed in a case, and the mobile in-core instrumentation system detector described in 11a is inserted into the core of the reactor. In a detector drive device for a mobile in-core instrumentation system that is driven by a moving member, the case has a case window that is removably covered by a lid and an exhaust port, and the exhaust port maintains negative pressure inside the case. This is what I did.

In addition, the method of using the detector drive device of the mobile in-core instrumentation system according to the second invention of the present invention is to remove the lid from the window of the case of the detector drive device, and insert the torque detector through this window. The above is the drive shaft of the cable drive mechanism!・The load on the drive shaft is detected by the torque measuring device while the internal air is exhausted from the exhaust port formed in the case, and the movable in-core instrumentation system detector is activated. This is a method for measuring 11 Jl-lux.

(Function) This detector drive device for the mobile in-core instrumentation system removes the lid from the window of its case, inserts a torque measuring device into the wooce through this window, and drives the cable drive mechanism with this torque measuring device. Connect to the shaft.

At that time, the air inside the case of the detector drive device is exhausted from the exhaust port, and the inside of the case is maintained at negative pressure. Therefore, the inside air does not flow out through the window of the case, and the outside air passes through this window. A flow of air is formed that flows into the case and is discharged from the exhaust port. With this air flow formed, a 1-lux measuring device is connected to the drive shaft, and this torque measuring device measures the load on the drive shaft. Torque is detected and the driving torque associated with the movement of the mobile in-core instrumentation system detector is measured.

In addition, when electrically detecting the motor rotational speed of the drive motor of the cable drive mechanism and its power consumption, the load torque of the drive shaft of the cable drive mechanism can be electrically detected from a remote location. It is possible to freely calculate the load torque during reactor operation and measure the driving torque accompanying the movement of the mobile in-core instrumentation system detector.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

A mobile in-core instrumentation system (TI) calibrates a power range neutron flux detector housed in the reactor pressure vessel of a boiling water reactor.
The overall arrangement of P) is the same as that shown in FIG. 3, so a description thereof will be omitted.

Is the mobile in-core instrumentation system a detector drive device that drives the mobile in-core instrumentation system detector (not shown)? 220 as shown in FIG. The detector drive device 2011 has a box-shaped case 21 that rotatably accommodates a winding end 22, and a drive cable 23 is wound around the winding end 22.

The drive cable 23 wound around the take-up cable 22 is inserted into the guide tube 27 through the drive unit 26 of the cable drive mechanism 25, and a mobile in-core instrumentation system detector (hereinafter referred to as Senna) (not shown) is installed at the tip of the drive cable 23. ,,) are attached. The drive unit 26 is connected to a reduction gear M429 from the drive motor 28 via an electromagnetic clutch 30, and the clutch action of the electromagnetic clutch 30 causes the drive motor 28 to
The driving force is transmitted to the drive shaft 31 of the drive unit 26 as necessary. The speed reduction mechanism 29 is, for example, one A-
The drive motor 28 has a built-in encoder (not shown), which controls the motor rotation speed and detects the rotation speed. 1 encoder is connected to a motor controller (inverter) not shown, and this motor controller performs feedback control of the motor rotation speed, while outputting the rotation speed detection signal to the control panel in the central control room or the field control panel 33. .

On the other hand, on the side of the case 21 is a cable drive mechanism 25!
A circular window 34 is formed corresponding to the JI moving axis 31,
This circular window 34 is detachably opened with a lid 35. This lid body 35 is removed when measuring torque with the TIP detector, and a torque detector such as a torque wrench 36 is connected to the drive shaft 31 through the circular window 34.

Further, the case 21 of the detector driving device 20 includes, for example, an I
An exhaust port 38 is formed in the negative portion, and an exhaust pipe 39 is provided at the exhaust port 38. This exhaust pipe 39 is connected to exhaust equipment such as an exhaust duct 41 that air-conditions a storage chamber 40 that accommodates the detection mechanism 20.

Further, reference numeral 33 is a field control board of the detector driving device 20, and this control board 33 has a [-ta controller, electromagnetic quantity 1!]. It has a built-in electric circuit consisting of a Jl unit, a relay, a timer, a transformer, and a motor wattmeter (all not shown).

Next, the operation of the detector driving device will be explained.

A detector driving device 20 that attempts to measure the driving torque accompanying the movement of a mobile in-core π1-system detector is selected from a plurality of detector driving devices 20 installed in a nuclear power plant such as a boiling water reactor. Select and select detection i! ! i drive device 2
The lid body 35 is removed from the circular window 34 of No. 0.

When the container body 35 is removed, the circular window 34 is opened, and the air outside the detector driving device 20 is sucked into the case 21 through the circular window 34. The sucked air is guided from the exhaust port 38 to the exhaust duct 41 through the exhaust pipe 39, and is exhausted from the exhaust duct 41. At this time, the detector driving device 20
The dust inside is carried by the air flow and sucked into the exhaust duct 41, and does not leak out from the circular window.

After recognizing this air flow, the operator inserts a 1-lux detector such as a torque wrench through the circular window 34, and sets it on the drive unit drive shaft 31 of the cable drive 1EIJ FM JM 25.

Next, operate the switch of the field control 111511I33 to operate the 'Js magnetic hoe clutch 30, and the output shaft of the deceleration mechanism 29 and the drive unit 26 are moved by the clutch action.
The drive shaft 31 is disconnected from the drive shaft 31, and the drive shaft 31 is made free.

In this free state, a torque detector such as the torque wrench 36 is rotated to drive the drive cable 23 in the direction in which it is inserted into the core of the reactor pressure vessel. As a result, the drive cable 23 is pulled out from the take-up reel 22, passes through the guide tube 27, and is inserted into any power range detector assembly (see FIG. 4) in the reactor pressure vessel. When inserting the drive shaft 31, a torque detector such as a torque wrench 36 is used.
Measure the load torque at any time.

When the measurement of the torque is completed, the drive cable 23 is handled from that output range detector assembly and inserted into the next output range detector assembly, and the load torque of the drive unit drive shaft 31 is similarly measured. . This switching is performed by an indexing device (see FIG. 4). The indexing device undergoes a switching operation once the drive cable 23 is pulled out to the indexing device, and the drive cable 23 is switched and reinserted. When the measurement of one torque load is completed in this way, the detector is shifted to the next detector driving device 20,
Torque measurement is performed by a worker, and the driving torque associated with the movement operation of the mobile in-core instrumentation system detector is measured.

Next, a method for electrically measuring load torque will be explained.

When the drive motor 28 in the detector drive device 20 is supplied with electric power from the site a, II panel 33 that houses the electric circuit, the drive motor 28 moves the drive cable 23 in the direction in which it is inserted into the core of the reactor pressure vessel. driven by At this time, the rotation number and rotation speed (rotation number 7 seconds) are detected by the encoder built into the drive motor 28, and the detected motor rotation speed is controlled by the motor controller and roller. It outputs the rotation speed signal.

On the other hand, the electric power supplied to the drive motor 28 is measured by a wattmeter in the on-site AI control panel 33, and the power consumption (W) is output. This power consumption output is expressed as 1-lux (T
), that is, 1-luke (T)-power (W) 7 rotation speed (ω)...
...(1) If you input it to a total of n machines that have the software, the drive motor 28
The driving torque value can be known.

In this way, the drive cable 2 is installed inside the output area detector assembly.
3, and measure the driving torque at that time. When the measurement of the driving torque accompanying the insertion of one output area detector assembly is completed, switch using the indexing device in the same way as the torque measurement in work 0, and proceed to the next one. The drive cable 23 is inserted into the corresponding guide tube of the power range detector assembly to measure the drive torque.

In this electric drive torque measurement, the torque measurement value includes losses from the drive motor 28, reduction gear M429, etc., so the electric torque measurement value becomes larger than the torque measurement value by the worker by this loss.

On the other hand, if the insertion speed of the drive cable 23 by the drive 28 is increased, the power consumption per minute unit time increases and the measured electrical torque value increases. For this reason, in the electrical measurement method, the electrical torque measurement value must be measured by the operator!・It is necessary to perform an operation to match the measured value.

Specifically, as shown in Figure 2, the torque measurement value by the worker is represented by a solid line a, and the driving torque was electrically measured at a rotational speed equivalent to the torque measurement speed by the work opening. At this time, this electrical torque measurement value is represented by point FIIb. From this graph, the difference between the electrical torque measurement value and the torque measurement value by the worker is set as the torque coefficient α, and the torque coefficient α is subtracted from the electrical torque measurement value.

Therefore, considering 1 Herk coefficient α from equation (1), torque (T) is calculated as follows: Torque (T) - (Power (W) 7 Rotational speed (ω) - Torque coefficient (α)) (2) The torque (T) can be calculated from this equation (2).

In addition, Fig. 3 shows the solid line a, which is the torque measurement value by the worker.
The electrical torque measurement value when the detector driving device 20 is actually operated is shown by a dashed line C. In actual operation, the detector drive device 20 operates at low speed when starting the drive cable 23 or when guiding the drive cable 23 to the reactor core, and operates at high speed in other areas.

This is because the detector driving device 20 is connected to a plurality of output area detector aggregates, for example, 10 locations, so that the time for reciprocating is shortened. Therefore, the electrical torque measurement value of the drive torque of the drive motor represented by the dashed line C becomes high in the middle, and this high torque measurement value indicates that the drive cable insertion speed is high. .

In the high-speed region, the load torque of the drive shaft 31 of the cable drive mechanism 25 that is the same as the torque measurement value by the worker can be collected by subtracting the increase in the electrical torque measurement value due to high-speed operation as a correction coefficient β. can.

According to this embodiment, when measuring the driving torque, the dust inside the detector driving device 20 can be discharged from the exhaust port 38 to the air conditioning exhaust duct 41.
Even though air may flow inside, the dust does not leak out, so there is no chance of dust adhering to workers' clothes and increasing radiation exposure.

In addition, when the drive torque is calculated from the motor rotation speed of the drive motor 28 and the motor dLl power consumption, this can be done by remote control and there is no need to approach the detector drive device 20, so during normal operation Torque measurements can also be made. At this time, since there is no need for the operator to measure torque, torque data can be collected at any time without exposure to radiation and in a short period of time, making it possible to determine the optimal time to replace the guide tube.

In this electrical torque measurement, once the torque measurement is carried out by the work Q and the torque coefficient is obtained, the same data as the torque measurement value by the worker can be collected from now on by electrical measurement, so the evaluation becomes easy.

In one embodiment of the present invention, an example has been described in which the detector driving device has a circular window formed on the side surface of the case, but the window shape is not limited to circular. Additionally, the field control panel may be provided within the detector drive and may be cleaned using a dedicated vacuum pump and filter to remove dust within the detector drive.

Electrical torque measurement can be remotely controlled by pressing a button from the TIP drive control room in the central control room.

〔Effect of the invention〕

As described above, in the present invention, the case of the detector drive device is provided with a window for putting in and taking out the torque measuring device and an exhaust port,
This exhaust port maintains negative pressure inside the case, so when the lid is removed and the window is opened, the air inside the case does not leak out through this window, and the outside air conversely flows through the window into the case. flow inside. Therefore, it is possible to reliably prevent activated dust from scattering to the outside through the window, and the radiation exposure during work Q can be significantly reduced, thereby improving the workability of torque measurement work.

In addition, since there is no risk of workers being exposed to radiation, it is possible to increase the number of torque measurements, resulting in more data, and it is possible to determine the optimal time to replace the guide tube.As a result, the guide tube can be effectively replaced. It can be used for many purposes and has a long lifespan, so radioactive waste can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a detector drive device for a mobile in-core instrumentation system according to the present invention, and FIGS. 2 and 3 show a detector drive device for a mobile in-core instrumentation system. Fig. 4 is an overall configuration diagram showing a mobile in-core instrumentation system attached to a nuclear reactor, and Fig. 5 is a perspective view showing a conventional detector drive device. be. 20...Detector driving device, 21...Case, 22.
...Take-up reel, 23...Drive cable, 25...
Cable drive mechanism, 26... Drive unit, 28
... Drive Tanabata, 29 ... Reduction mechanism, 30 ... Electromagnetic clutch, 31 ... Drive shaft, 33 ... Field control 2
1I board, 34... Window, 35... Lid, 36... Torque wrench (torque detector), 38... Exhaust port, 41
···Exhaust duct. Applicant's agent Hisashi Hatano Figure 1 Insertion distance Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. A take-up reel around which a drive cable to which a mobile in-core instrumentation system detector is attached is wound, and a cable drive mechanism for taking in and out the drive cable wound around this take-up reel, as a case. In the detector drive device for a mobile in-core instrumentation system that is housed in a case and drives the mobile in-core instrumentation system detector to be inserted into and pulled out from a core of a nuclear reactor, the detector drive device is configured to be detachably attached to the case by a lid body. 1. A detector drive device for a mobile in-core instrumentation system, characterized in that a covered case window and an exhaust port are formed, and the inside of the case is maintained at negative pressure by the exhaust port. 2. A detector drive device for a mobile in-core instrumentation system according to claim 1, wherein the exhaust port is connected to an air conditioning exhaust duct via an exhaust pipe. 3. A detector for a mobile in-core instrumentation system according to claim 1, wherein the cable drive mechanism includes a drive motor, and is provided with an electric circuit for detecting the motor rotation speed and motor power consumption of the drive motor. Drive device. 4. Remove the lid from the window of the case, insert the torque detector through this window, connect the torque measuring device to the drive shaft of the cable drive mechanism, and exhaust the air inside from the exhaust port formed in the case. The use of a detector drive device for a mobile in-core instrumentation system, characterized in that the load on the drive shaft is detected by a torque measuring device, and the driving torque of the mobile in-core instrumentation system detector is measured. Method. 5. The load on the drive shaft of the cable drive mechanism is electrically detected from the measured values of the motor power consumption and motor rotation speed of the drive motor installed in the cable drive mechanism, and the mobile in-core instrumentation system detector is driven. Claim 4 measuring torque
How to use the detector drive device of the mobile in-core instrumentation system described in 2. 6. Calculate the torque coefficient by comparing the electrical torque measurement value obtained by electrically detecting the load on the drive shaft of the cable drive mechanism with the torque measurement value detected by the torque measuring device, and apply the torque coefficient to the above electrical torque measurement value. The mobile core according to claim 5, wherein the load on the drive shaft is determined by multiplying by a torque coefficient to be equal to the torque measurement value, and the drive torque of a mobile in-core instrumentation system detector is measured. How to use the detector drive device of the internal instrumentation system.