JPS62192696A - Leakage-detection identification device in nuclear reactor container - 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 (Technical Field of the Invention) The present invention relates to a nuclear reactor containment vessel that detects leakage of water or steam from valves, pipes, etc. in the reactor containment vessel of a nuclear couplant and identifies the leakage location. This invention relates to an internal leakage detection and identification device.

(Technical Background of the Invention) In general, in nuclear power plants, etc., leaks within the reactor containment vessel are detected by changes in temperature sensors and pressure sensors.Multiple of these temperature sensors and pressure sensors are arranged. It is now possible to determine the values at several locations within the reactor containment vessel and the overall average temperature and pressure changes.

[Problems with background technology]

However, when there are few leakage sounds, it is difficult to identify their occurrence and location just by monitoring the overall balance using such temperature sensors and pressure sensors. As a result, the discovery of the leak may be delayed, resulting in damage to surrounding equipment.
Maintenance measures after discovery may not be effective.

Leakage is also likely to occur from pipe joints such as valves. For this reason, when starting up the reactor after periodic inspection,
The reactor pressure is 30 to 9/ci, 70 to 70'J/cm.
At this point, reactor startup is temporarily halted and work is being carried out to check for water leaks in various parts of the reactor containment vessel. This work requires bringing the reactor to subcriticality, and it takes a long time from the start of the work until it is finished and the start-up operation is resumed. In addition, inspection work inside the reactor containment vessel is radiation work, and it is expected that such work on the containment vessel will be reduced by reducing Tockle Man Rem.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and it facilitates early detection and location identification of leaks in the reactor containment vessel, reduces inspection work inside the reactor containment vessel, and reduces the start-up time of the nuclear couplant. The purpose of the present invention is to provide a leakage detection and identification device in a reactor containment vessel that can improve operating efficiency by shortening the time and reduce equipment damage caused by leakage.

[Summary of the invention]

The leak detection and identification device in the reactor containment vessel according to the present invention includes a vibrator installed in the reactor containment vessel and an Okazo sensor that moves within the vibrator and obtains thermal infrared image data inside the reactor containment vessel. -, an image creation device that obtains a thermal infrared image of the inside of the reactor containment vessel based on the image data from the rotation sensor "-, and The present invention is characterized by being equipped with a diagnostic device that detects leakage in the reactor containment vessel and identifies the location of the leakage.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

As shown in FIG. 1, a plurality of guide vibes 3 for moving imaging sensors are installed in a reactor containment vessel 2 that houses a nuclear reactor 1. Inside this Wt image sensor movement guide vibe 3, a sensor 4 for obtaining thermal infrared image data is movably inserted together with a signal cable 5, not shown in FIG. Window holes 6 are drilled at regular intervals in the sensor movement guide vibe 3, through which imaged data of piping, etc. inside the reactor containment volume i1!!?2 is obtained and transferred to the leakage detection device. There is.

FIG. 3 shows a leak detection device. That is, the sensor signal 101 from the image sensor 4 is sent to the image creation device 7 and converted into image information. The image information signal 102 is sent to a diagnostic computer, that is, a diagnostic device 8. On the other hand, a process variable signal 103 from a process computer 9 that obtains plant state data is sent to a state determination device 10, and the plant state is determined based on process variables such as water level, pressure, and radioactivity in the reactor. be done. The condition determination device 10 searches for a condition image matching the current state of the plant sent from the first storage device 11, and transfers the reflex image information signal 104 to the diagnostic device 8 as a reflex. The diagnostic device 8 compares the current image and the Ref-France image and displays the determination result on the CRT 12. In the determination, reference is made to the determination rules stored in the second storage device 13 and data on structures (vibrators, pumps, etc.) inside the reactor containment vessel. As a result of the determination, if more detailed information from the image sensor 4 is required, a control signal 105 is transmitted from the control device 14 to the image sensor drive device 15, the image sensor 4 is moved to a predetermined position, and the image sensor 4 is moved to a predetermined position. Make it perform the same action.

In this way, the current data and Ref France are compared, and it is determined whether there is a large difference between the two, and if the current data and the Ref France pattern match overall, it is determined to be OK (no leakage detected). In addition, if an abnormality is recognized,
A detailed analysis will be performed to identify whether there is actually a leak and where it is located.

Next, the action will be specifically explained.

The Wi image sensor 4 moves up and down within the reactor containment vessel 2, for example. When a leak occurs, if the fluid is a liquid, there should be a large disturbance in the heat distribution three-dimensionally below the leak site. Therefore, the positions at which detailed analysis data is collected at multiple vertical positions by the image sensor 4 are narrowed down to several positions from where large disturbances begin to appear. Next, the focal point of the VIfLi sensor 4 is changed at several points to obtain a thermal infrared image with the depth in the radial direction centered on the nuclear reactor 1 being changed. By doing this, the main candidates for where the leak is occurring in the vertical direction within the reactor containment vessel 2 and in the radial direction around the reactor 1 are determined. Note that these operations are performed according to problem-solving strategies stored in the second storage device 13, such as rules regarding the vertical position of the image sensor 4 and how to focus.

To the problem space created in this way, the next step is to apply the structure of the heat source, and finally determine which vibrator or valve is causing the leak.

FIG. 4 illustrates the structure of the space in question. In FIG. 4, a valve 17 is interposed in the middle of the via 16. The thermal infrared image of reflex 7 corresponding to this is illustrated in FIG. 5, where T, T2,
... is the boundary of temperature distribution. The image shown in FIG. 5 is obtained from the facts (installation data) regarding the plant structure incorporated in the storage device 13. On the other hand, suppose that an actual thermal infrared image is obtained as shown in FIG. In this case, it is assumed that the temperature JA of the vibrator 16, which is considered to be a heat source from the plant structure, is T1, and that the thermal infrared image shown in FIG. 6 was obtained due to leakage of the fluid flowing there.

In addition, in the case of Fig. 6, the leakage is due to the position of the disturbance,
It is estimated that it is not the pinhole 6 but the valve 17.

By determining the IW, leakage at the spatial location shown in FIG. 6 and a hypothesis of the location can be obtained. However, it is also assumed that the changes shown in FIG. 6 are influenced by other parts in the radial direction around the reactor. Therefore, this will be verified next using an image in which the focus of the image carrier sensor 4 has been changed.

FIG. 7 shows other structures targeted when the focus of the image sensor 4 is changed in the radial direction, such as another vibrator 16a.
Here is an example. Assume that the thermal infrared image of the vibrator 16a in FIG. 7 is converted to 1n as shown in FIG. 8, and matches the reflex 7 lance. Similarly, a thermal infrared image deeper than the space shown in FIG. 7 (on the reactor side) will also be analyzed. If no abnormality is found as a result, it is determined that the above-mentioned hypothesis is correct. The judgment result is shown on the display device in room 611 on the central side, that is, on the CRT 12.

According to such a configuration, since leakage detection is performed individually for each pipe, etc., even when the amount of leakage is small, the location of occurrence can be identified with extremely high accuracy. In particular, using thermal infrared images makes it easier to detect leaks.
This makes it possible to take prompt action.

Note that FIG. 9 shows another embodiment of the present invention. That is, the guide pipe 3 may be provided with window holes 6 facing in multiple directions, and by rotating the imaging C sensor 4, the space in multiple directions may be investigated. If this is the case, for example, the first
As shown in FIG. 0, by installing a pair of guide vibes 3 inside the reactor containment vessel 2, it becomes possible to sufficiently identify the leakage location. In the present invention, it goes without saying that the number and arrangement of the guide vibrators 3, the orientation of the window holes 6, etc. can be selected depending on the plant.

〔Effect of the invention〕

As described above, according to the present invention, leakage of water or steam from the valves and vibrator shades in the reactor containment vessel of nuclear reactors 1 to 1 can be prevented.
Detection and leak location identification can be performed accurately on-line or almost as quickly as possible, which reduces inspection work inside the reactor containment vessel, improves operating efficiency and reduces leakage by shortening the start-up time of the nuclear couplant. This has the effect of reducing equipment damage due to

[Brief explanation of drawings]

Fig. 1 shows one embodiment of the present invention, and is an explanatory diagram showing an example of installing a guide vibrator, Fig. 2 is a sectional view showing an enlarged main part of Fig. 1, and Fig. 3 is a signal processing FIG. 4, FIG. 5, and FIG. 6 are schematic diagrams showing examples of detection, hypothesis setting, and verification in the above embodiment, respectively. FIGS. Fig. 9 is a schematic diagram showing an example of hypothesis setting and verification of parts, Fig. 9 is a configuration diagram of a guide pipe showing another embodiment of the present invention, and Fig. 10 is an explanatory diagram of a guide vibe according to another embodiment. be. 1... Nuclear reactor, 2... Reactor containment vessel, 3... Guide vibe for moving the decoy image sensor, 4... JIG image sensor, 5... Signal cable, 6... Window Hole, 7...
- Image creation device, 8...Diagnostic device, 16...Pipe, 17...Valve. Applicant's agent Hatano Hisashi 1st district tea 2nd 3rd $4 rod 5th 73T2TtTt sheep 7 figure t;z tt it Adz vine 8 figure! Fig.-70

Claims (1)

[Claims] A pipe installed in the reactor containment vessel, an imaging sensor that moves within the pipe to obtain thermal infrared image data inside the reactor containment vessel, and an imaging sensor that moves within the pipe to obtain thermal infrared image data inside the reactor containment vessel, Diagnosis that detects leaks inside the reactor containment vessel and identifies leak locations by comparing the thermal infrared images with thermal infrared images taken during normal plant conditions. What is claimed is: 1. A leakage detection and identification device in a reactor containment vessel, comprising: