JPH03255989A - Monitor device for inside of nuclear reactor dry well - Google Patents

Abstract

PURPOSE:To monitor the inside of the nuclear reactor dry well optically in a stationary state from a remote place by making a scan in the nuclear reactor dry well with a laser beam and irradiating a part to be measured, and detecting its reflected light optically by a remote monitor means. CONSTITUTION:Scanning optical systems 53 and 54 control primary mirrors 56a and 56b and secondary mirrors 57a and 57b to scan the inside of the nuclear reactor well 30 longitudinally and laterally with the laser beam outputted by a laser device 6 to irradiate the part 47 to be measured as a place to be monitored with the laser beam. Further, the laser beam reflected from the part 47 to be measured by the irradiation is inputted to the photodetection part of a photodetection detection system 49 through a scanning optical system 48. The signal inputted to the photodetection part is inputted to the remote monitor means 50 provided outside the nuclear reactor storage container 21 and this means 50 compares the input signal with measurement data in a normal state to monitor the inside of the dry well 30 remotely. Further, the means 50 can monitor abnormality such as a defect and a leak in the part 47 to be measured in the stationary state even when the nuclear reactor is in operation.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) This invention relates to a monitoring device in a nuclear reactor dry well that optically monitors the inside of a nuclear reactor dry well from a remote location. This invention relates to a monitoring device inside a nuclear reactor drywell that can regularly monitor internal structures, piping systems, etc.

(Prior Art) A boiling water reactor as a light water reactor is configured as shown in FIG.
It is called RPV. )2 is stored. This RPV2 is RP
It is supported on a V-support pedestal 3.

On the other hand, the inside of the reactor containment vessel 1 is defined as a dry well 4, and each equipment piping of the main steam system 5, reactor water supply system 6, and reactor recirculation system 7 is arranged within this dry well 4. At the same time, a ventilation air conditioning system (not shown) for air conditioning the inside of the dry well 4 is provided. Additionally, a reactor auxiliary system and a reactor emergency system (both not shown) are provided around the reactor to ensure the safety of the reactor.

The main steam system 5, the reactor water supply system 6, the reactor recirculation system 7, the ventilation air conditioning system, and the internal structures of the reactor containment vessel 1, such as the reactor emergency system, the reactor pressure vessel 2, and the heat shield wall. are listed as monitoring target locations within the reactor dry well 4. These points to be monitored are mainly visually monitored by workers entering the dry well 4 during periodic inspections of the nuclear reactor.

2. Description of the Related Art A nuclear reactor is inspected at regular intervals (for example, one year) by stopping its operation for a predetermined period (for example, about three months). During this periodic inspection, dry well cover 8
In addition, the upper cover 1a of the reactor containment vessel 1 and the upper cover 2a of the reactor pressure vessel 2 are removed by the overhead crane 10, and the fuel installed in the reactor core is replaced. The rod drive mechanism 11 is disassembled and inspected.

In addition, during periodic inspections of nuclear reactors, water is drained from the main steam line and leak tests and overhauls are performed on the main steam isolation valve 12, and the main steam relief safety valve (not shown) is disassembled and inspected. ing.

In addition, the recirculation pump 7a of the reactor recirculation system 7 is inspected, and the monitoring target locations within the reactor dry well 4 are inspected to monitor for damage or abnormalities.

(Problem to be solved by the invention) Inside the reactor drywell 4 are the main steam system 5 and the reactor water supply system 6.
, the reactor recirculation system 7, the reactor emergency system, and many other components and piping, but it is in an environment that is affected by radiation and the work environment is poor, making it difficult for workers to access the inside of the dry well 4. It was not easy and difficult to monitor.

In particular, during the operation of the nuclear reactor, the inside of the dry well 4 is under a high temperature and high radiation environment. No method has been established to constantly remotely monitor monitoring target locations within the nuclear reactor dry well 4 under such an environment during reactor operation, nor has a remote monitoring device been developed for this purpose.

By the way, in order to monitor the inside of the reactor drywell during reactor operation, considering that the reactor is in an environment of high temperature and high radiation, it is necessary to use equipment that has excellent heat resistance, radiation resistance, and can withstand radiation noise. must not. Considering this noise countermeasure, a monitoring device that electrically processes signals is inappropriate as a monitoring device in the reactor dry well 4 and cannot be used.

From this point of view, the question has been how to develop a device that can constantly monitor the inside of a nuclear reactor dry well, which is in a high-temperature, high-radiation environment, from a remote location.

This invention has been made in consideration of the above-mentioned circumstances, and is a nuclear reactor that can optically and constantly efficiently monitor the interior of the reactor dry well, which has a poor working environment, from a remote location even during reactor operation. The purpose is to provide a monitoring device within a dry well.

Another object of the present invention is to provide a monitoring device in a nuclear reactor dry well that eliminates the need for noise countermeasures against radiation noise and has excellent heat resistance and radiation resistance.

Another object of the present invention is to provide a monitoring device for a reactor dry well, which has a simple structure and can identify a faulty location within the reactor dry well by monitoring from a remote location.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above-mentioned problems, a monitoring device in a nuclear reactor dry well according to the present invention includes a laser device that outputs a laser beam, and a laser beam output from the laser device. A scanning optical system that scans the beam in the dry well and irradiates it onto the part to be measured, a light detection system that receives the reflected light of the laser beam irradiated to the part to be measured, and a signal detected by this light detection system. It has remote monitoring means for detecting abnormalities such as defects and leakage in the part to be measured.

In addition, in order to solve the above-mentioned problems, in the monitoring device in the nuclear reactor dry well of the present invention, the laser device is provided with a plurality of oscillating parts that output laser beams at the top of the reactor containment vessel. The optical system has multiple systems corresponding to the oscillation section, and each of the above systems includes a rotatable primary mirror that scans the laser beam from the oscillation section;
It is constructed by combining a rotatable and movable secondary mirror that irradiates the part to be measured with a laser beam scanned by this primary mirror.

Furthermore, in order to solve the above-mentioned problems, this invention
The light receiving detection system has a light receiving detecting section provided in the oscillating section of the laser device, and is configured so that the reflected light of the laser beam irradiated on the part to be measured is input to the light receiving detecting section through the scanning optical system. The purpose of the present invention is to provide a monitoring device within a nuclear reactor drywell.

(Function) This monitoring device inside the reactor dry well uses a scanning optical system to scan the inside of the reactor dry well with a laser beam output from a laser device and irradiates it onto the part to be measured. Since abnormalities such as defects and leaks in the parts to be measured are detected optically using remote monitoring means, monitoring points in the reactor dry well, which has a poor working environment, can be monitored remotely even during reactor operation. It is possible to monitor regularly and efficiently.

This monitoring device only needs to be equipped with a scanning optical system that scans the laser beam inside the reactor dry well. Since this scanning optical system optically scans the laser beam, it is susceptible to noise such as radiation noise. It has excellent heat resistance and radiation resistance.

In addition, this monitoring device is equipped with multiple systems of scanning optical systems that scan laser beams within the reactor dry well, making it possible to identify the parts to be measured, which are the monitoring targets, within the reactor dry well. , the scanning optical system is a combination of a primary mirror and a secondary mirror, and the light receiving and detecting system uses the scanning optical system described above to detect reflected light, so the structure is simple and it is suitable for use in nuclear reactors. The monitoring target location within the dry well can be efficiently detected from a remote location.

(Embodiment) Hereinafter, an embodiment of the monitoring device in a nuclear reactor dry well of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an example of a monitoring device in a nuclear reactor dry well according to the present invention, and FIG. 2 shows an example in which the present invention is applied to a boiling water reactor as a light water reactor.

As shown in Figure 2, a boiling water reactor has a reactor building 2.
A reactor containment vessel 21 is housed within the nuclear reactor containment vessel 21, and a reactor pressure vessel (RPV) 22 is housed within this reactor containment vessel 21. The RPV 22 is supported on an RPV support pedestal 23, and a suppression chamber 24 is formed below the RPV 22.

On the other hand, a reactor core 25 in which nuclear fuel is arranged is formed within the reactor pressure vessel 22, and heat generated in the reactor core 25 is transferred to the reactor coolant. This coolant receives heat as it passes through the core 25 and boils, and then is separated into water and steam in a steam separator 26 and a steam dryer 27. The separated steam is guided to a turbine system (not shown) via the main steam system 28 to drive a steam turbine. After the steam that has done work in the turbine system is condensed and becomes condensate, it is supplied into the RPV 22 via the reactor condensate/water supply system 29.

Furthermore, the space within the reactor containment vessel 21 is defined as a reactor dry well 30, and within this dry well 30, the equipment and piping of the main steam system 28 and the reactor water supply system 29 are arranged. Some of the piping equipment for the reactor recirculation system 31 and the equipment for the reactor auxiliary system 32 and the reactor emergency system 33 are provided.

The reactor recirculation system 31 circulates the coolant in the reactor pressure vessel 22 back to the reactor core 25.

The reactor auxiliary system 32 is installed around the reactor, and includes a reactor coolant purification system 35 used during reactor operation, a reactor shutdown cooling system 36, a reactor auxiliary equipment cooling system, etc. The reactor emergency system 33 ensures the safety of the reactor in the event of a serious accident such as a pipe rupture or other abnormal situation, and includes a reactor containment vessel cooling system 37, a low pressure injection system (reactor residual heat removal system) 3
8. High pressure core spray system 39, low pressure core spray system 40
, an automatic pressure reduction system 42 having a safety relief valve 41, and a water injection system 43.

By the way, the monitoring device 45 in the reactor dry well is
A laser device 46 that is configured as shown in the figure and outputs a laser beam such as a pulsed laser, and this laser device 4
The laser beam output from 6 is sent to the reactor dry well 3.
a scanning optical system 48 that scans within 0 and irradiates the part to be measured 47 which is the monitoring target part; a light reception detection system 49 that receives reflected light from the part to be measured 47; and a signal detected by the light reception detection system 49. It has a remote monitoring means 50 for detecting and monitoring abnormalities such as defects and leakage in the part to be measured 47 from a remote location.

The laser device 46 is located at the top of the reactor containment vessel 21 (upper lid 21
a) A plurality of oscillators 46a, 4, for example, two oscillators 46a, 4 provided in
It has 6b. The oscillating units 46a and 46b may be the laser devices themselves, or they may be oscillating units for laser beams output from the laser device 46 and input via the half mirror 51 and the angle mirror 52, as shown by the chain line. Good too. In the former case, the laser device 46 is provided on the upper lid 21a of the reactor containment vessel 21, and in the latter case, the laser device 46 is arranged outside the reactor containment vessel 21.

The scanning optical system 48 includes oscillation units 46a and 46 of the laser device 46.
A plurality of systems 53 and 54 are provided corresponding to the scanning optical systems 53 and 54, respectively, and each scanning optical system 53, 54 is provided directly below the oscillating section and has a rotatable primary mirror 56a.

56b, and secondary mirrors 57a, 57b which are provided apart from the primary mirrors 56a, 56b and are rotatably and movably provided. The primary mirrors 56a and 56b are rotatably controlled by a known rotation control device, and their rotational positions and rotation angles are adjusted by operational control of the rotation control device. In addition, the secondary mirror 57
a and 57b are also rotatably and movably supported by a rotation control device supported by a known moving mechanism. Scanning optical system 53
, 54 are primary mirrors 56a, 56b and secondary mirror 57a.
, 57b, the laser beam outputted from the laser device 46 can be scanned vertically and horizontally within the reactor dry well 30, and can be irradiated to the part to be measured, which is the part to be monitored.

Furthermore, by irradiating the part to be measured 47 with the laser beam, the laser beam reflected from the part to be measured 47 passes through the scanning optical system 48 and is input to the light receiving part of the light receiving and detecting system 49 provided in the oscillating parts 46a and 46b. Ru. The signal input to the light receiving unit is transmitted to the reactor containment vessel 2 via an optical fiber cable 59, etc.
The inside of the reactor dry well 30 can be remotely monitored by inputting the data to a remote monitoring means 50 provided outside the nuclear reactor dry well 30 and comparing it with normal measurement data by the remote monitoring means 50. With this remote monitoring means 50, it is possible to constantly monitor abnormalities such as defects and leakage of the part to be measured 47 even during the operation of the nuclear reactor.

At this time, the blind spots of the two detection systems can be reduced by appropriately combining the arrangement of the oscillators 46a, 46b and the light receiving section, and the operations of the primary mirrors 55a, 56b and secondary mirrors 57a, 57b of the scanning optical system 53.54. It is set to the minimum.

By the way, the monitoring targets in the reactor dry well 30 include (1) the reactor pressure vessel (RPV) 22, (2) the equipment piping of the reactor recirculation system 31, (3) the reactor main steam system 28, and Reactor water supply system 29, reactor auxiliary system 32, reactor emergency system 33
Equipment belonging to the reactor pressure boundary such as (4) Automatic depressurization system 42 equipment and piping such as relief safety valves, (5) RPV support pedestal 23, (6) Reactor containment vessel internal structures such as heat shield walls, ( 7)
Ventilation and air conditioning equipment, (8) and others.

Among these points to be monitored, monitoring of the reactor recirculation system 31, reactor emergency system 33, reactor water supply system 29, make-up water system, ventilation air conditioning system, and reactor containment equipment is particularly strongly required for the following reasons. ing.

It is desirable that the reactor recirculation system 31 be able to monitor the inside of the reactor dry well 30 during reactor operation in order to streamline periodic reactor inspections, reduce radiation exposure to workers, and improve equipment operability. .

In addition, the core spray system 39-40 of the reactor emergency system 33 and the high-pressure water injection system must be monitored in order to simplify reactor operation, maintenance and inspection work, and water venting work.
Through this monitoring, it is possible to streamline periodic inspections, reduce equipment production costs, and reduce the amount of waste generated.

Additionally, the ventilation air conditioning system requires monitoring to improve the reliability of equipment located within the reactor drywell 30. Reactor containment facilities require monitoring to improve the working environment, and enhanced monitoring can improve equipment reliability and extend its lifespan.

Next, another embodiment of the monitoring device 45A in the reactor dry well 30 will be described with reference to FIG.

This monitoring device 45A is provided with a laser device 46 and remote monitoring means 50 outside the reactor containment vessel 21. The laser beam output from the laser device 46 passes through a cable penetration section 62 of the reactor containment vessel 21 via an optical fiber cable 60 to a fiber probe 63a as an oscillating section.

63b, 63c, and irradiates a portion to be measured 65 such as a pipe 64 provided in the reactor dry well 30 from these fiber probes 63.63b, 63c.

Each fiber probe 63a, 63b, 63
c is provided on the probe support board 66. The probe support plate 66 performs an angle changing operation at certain timings by a remotely controlled driving means (not shown), and functions as a scanning optical system. By giving the probe support plate 66 an angle changing operation, each fiber probe 63s, 63b
, 63c are scanned and irradiated onto the part to be measured 65.

The laser beam reflected by irradiating the part to be measured 65 is transmitted to fiber probes 63a and 63b.

63c, and are input to the photodetectors 67a, 67 of the remote monitoring means 50 via the optical fiber cable 60.
b, 67c. In this case, the fiber probes 63 a, 63 b, and 63 c have the functions of both the oscillating part of the laser device 46 and the light receiving part of the light receiving detection system 49.

Photodetectors 67a, 67b of remote monitoring means 50A.

The optical signal inputted to 67c is converted into an electrical signal, and is sent to amplifiers 68a, 68b, 68c and frequency tracker 69a.
, 69 b, and 69 c, and are input to the control unit 70 such as a CPU or a microcomputer. The control unit 70 performs various calculations such as the three-dimensional vibration velocity and maximum vibration direction velocity of the object, and based on the results of these calculations and the structure inside the reactor dry well 30, the measured part 6
5 is identified, three-dimensional vibration information of this portion is measured, and abnormalities such as defects and leakage in the portion to be measured 65 can be detected from the measurement results.

In this vibration measurement, it is impossible to directly measure and monitor the part to be measured, but the direction and vibration speed of abnormal vibration in the part to be measured 65 is detected by laser measurement, and this measurement result is combined with the reactor dry well. The location where the abnormal vibration occurs can be identified from the structure (configuration) within the device 30.

FIGS. 4 and 5 show other modifications of the nuclear reactor dry well internal monitoring device.

The monitoring devices 70A and 70B shown in these modified examples are
This system enables atmospheric components within the reactor dry well to be remotely measured and monitored using spectroscopic analysis.

Of these, the monitoring device 70A shown in FIG.
The laser beam is guided into the reactor dry well 30 via the reactor dry well 30, and a plurality of laser beam paths are formed within the reactor dry well 30. Each optical fiber cable 71a
, 71b, 71c pass through similar optical fiber cables 72a, 72b, 72c to detectors 73a, 73b for light absorption measurement as a light reception detection system.
, 73c, and is also detected by a Raman measurement detector provided in the laser device I46. Through these detections, the average concentration and average temperature during the optical path length of the laser beam scanned inside the reactor dry well 30 are measured, and the concentration distribution of the atmospheric components is determined using the diffusion equation.

However, because of the noise light (reflected light) from piping and structures arranged in a complicated manner inside the reactor dry well 30, it is not common practice to scan the laser beam for measurement as shown in Figure 4. Since this is accompanied by difficulties, for practical use it is efficient to measure as shown in FIG.

The monitoring device 70B shown in FIG. 5 includes the laser device 46.
46 is guided into the reactor dry well 30 via optical fiber cables 74a, 74b, and the laser beams from the optical fiber cables 74a, 74b are diffused and irradiated to eliminate the influence of noise light. Take measures against reflected light noise. This laser beam is scanned inside the reactor dry well 30 to perform measurements covering the dry well space.When an abnormality is detected in a certain optical path when the laser beam is scanned, another laser beam moves along that optical path. and identify the location of the abnormality.

As described above, an optical monitoring method that uses a laser beam for monitoring is suitable in consideration of the working environment in the reactor dry well 30, the requirements for remote measurement, and countermeasures against noise such as radiation noise.

〔Effect of the invention〕

As described above, in the reactor dry well monitoring device according to the present invention, the laser beam output from the laser device is scanned by the scanning optical system within the reactor dry well to irradiate the part to be measured. The reflected light is detected by the light receiving detection system and then optically detected by the remote monitoring means for monitoring, so that the monitoring target area in the reactor dry well, which has a poor working environment, can be monitored from a remote location even during reactor operation. can be regularly and automatically monitored efficiently.

In addition, this monitoring device only needs to be provided with a scanning optical system that scans a laser beam in the reactor dry well.
Since this scanning optical system performs optical processing, the interior of the reactor dry well can be monitored efficiently and accurately without being affected by noise such as radiation noise. Becomes excellent in sex.

Furthermore, since multiple scanning optical systems are installed inside the reactor drywell, it is easy to fix the location to be monitored using multiple scanning optical systems, and the scanning optical system is a combination of a primary mirror and a secondary mirror. Since the light reception and detection system uses a scanning optical system to receive the reflected light, it has a simple structure and can efficiently monitor the monitoring target location in the reactor dry well from a remote location.

Furthermore, since the inside of the dry well can be optically and remotely monitored by the monitoring device in the reactor dry well of the present invention, the reliability of the nuclear reactor plant can be maintained, and furthermore, during reactor inspection. The number of patrol items can be reduced and streamlined.

[Brief explanation of drawings]

FIG. 1 is a cutaway sectional view showing an embodiment of a monitoring device in a nuclear reactor dry well according to the present invention, FIG. 2 is a diagram showing a boiling water reactor to which this invention is applied, and FIG. 3 is a diagram showing the present invention. FIGS. 4 and 5 are diagrams illustrating other embodiments of the monitoring device in the reactor dry well according to the above, and FIGS. 1 is a diagram showing a general cross-sectional structure of a boiling water reactor. 20... Reactor building, 21... Reactor containment vessel, 2
2...Reactor pressure vessel, 23...RPV support pedestal, 25...Reactor core, 28...Main steam system, 29...
・Reactor (condensate) water supply system, 30...Reactor dry well, 31...Reactor recirculation system, 32...Reactor auxiliary system, 33...Reactor emergency system, 39.40 ...Core spray system, 42...Automatic depressurization system, 45.45A, 70
A, 70B...Monitoring device, 46...Laser device, 4
6a, 46b... Oscillator section, 47.65... Measured section, 48. 53° 54... Scanning optical system, 49... Light reception detection system, 50, 50A... Remote monitoring means, 56a,
56b...Primary mirror, 57a, 57b...Secondary mirror, 60...Optical fiber cable, 63a-63c.
...Fiber probe (oscillation section, light receiving section), 66...
Probe support plate (scanning optical system).

Claims (1)

[Scope of Claims] 1. A laser device that outputs a laser beam, a scanning optical system that scans the laser beam output from the laser device in a dry well and irradiates the part to be measured, and a scanning optical system that irradiates the part to be measured with the laser beam output from the laser device. an atom characterized by having a light reception detection system that receives the reflected light of the laser beam, and a remote monitoring means that detects abnormalities such as defects and leakage in the part to be measured from the signals detected by the light reception and detection system. Monitoring device inside the furnace drywell. 2. The laser device is provided with a plurality of oscillating sections that output laser beams at the top of the reactor containment vessel, while the scanning optical system has multiple systems corresponding to the oscillating sections, and each of the above systems emit laser beams from the oscillating section. 2. The nuclear reactor dry well according to claim 1, comprising a combination of a rotatable primary mirror that scans the beam and a rotatable and movable secondary mirror that irradiates the measurement target with the laser beam scanned by the primary mirror. monitoring equipment within. 3. The light reception detection system has a light reception detection section provided in the oscillation section of the laser device, and the reflected light of the laser beam irradiated onto the measurement target is inputted to this light reception detection section through the scanning optical system. A monitoring device in a nuclear reactor dry well according to claim 1, wherein the monitoring device is formed in a nuclear reactor dry well.