JP5454861B2 - Nondestructive inspection system - Google Patents

Description

The present invention relates to non-destructive inspection system is useful when applied to particular diagnostic use the reactor facility radiation.

  Conventionally, when diagnosing the occurrence of cracks in the pipes through which cooling water flows, the degree of thinning, etc., as shown in FIG. In addition, the worker 2 enters the reactor containment vessel 3 and performs a predetermined operation while the operation of the reactor 1 is stopped. That is, the worker 2 carries the radiation source 4 and the radiation detector 5 and goes to the installation location of the inspection object 6 which is a pipe for circulating the cooling water of the facility to be diagnosed, for example, the nuclear power facility. Image information indicating the state of the diagnostic part was obtained by making the radiation source 4 and the radiation detector 5 face each other with the diagnostic part interposed therebetween. That is, so-called nondestructive inspection is performed in which radiation emitted from the radiation source 4 is transmitted through the diagnostic site and predetermined image information is obtained using the transmitted radiation.

  As a known document disclosing a nuclear reactor structure diagnostic method, for example, Patent Document 1 can be cited.

JP 2008-175563 A

  In the facility diagnosis as described above, since the worker 2 must carry the radiation source 4 and the radiation detector 5 and go to a predetermined diagnosis work, there has always been a risk of exposure. Also, when the inspection object 6 in the reactor containment vessel 3 is a facility such as piping, and the worker 2 enters the reactor containment vessel 3 and performs a predetermined work. In order to ensure the safety of the worker 2, the operation of the reactor 1 is normally stopped. As a result, the operating rate of the nuclear reactor 1 was reduced.

  Furthermore, in the prior art, a film or an image plate is widely used as the radiation detector 5, but in any case, later development is required. That is, the equipment diagnosis result could not be obtained in real time. In order to obtain equipment diagnosis results in real time, a desired nondestructive inspection system may be constructed using a scintillation CCD camera, an X-ray image intensifier, a flat panel X-ray sensor, or the like. This is because the inspection object can be taken as a planar image in real time or can be measured online. However, when trying to use an existing one, a new problem occurs depending on the application. For example, when a facility inspection such as nuclear facility piping is performed, the reactor facility piping must be an inspection object for nondestructive inspection. In this case, the nondestructive inspection needs to be performed in a narrow place where many pipes and the like are arranged, and the radiation detection unit needs to be miniaturized as much as possible. On the other hand, there is no radiation detection device suitable for efficiently performing real-time nondestructive inspection by designating a certain inspection area in a narrow place such as in a reactor containment vessel, and its appearance is expected. It was.

In view of the above prior art, the present invention is capable of diagnosing nuclear facilities and the like that are safely and easily in a radioactive atmosphere without affecting the human body and that need to be inspected in many narrow spaces. an object of the present invention is to provide a non-destructive inspection system that can.

The first aspect of the present invention for achieving the above object is as follows:
Non-destructive to the inspection object that has a radiation source that is a fixed facility that irradiates radiation or a radiation source that irradiates radiation by contacting this facility in the vicinity and is installed in a closed space An inspection system ,
Radiation detection means for detecting radiation irradiated from any of the radiation sources and transmitted through a predetermined region of the inspection object;
Moving means for moving the radiation detecting means in a horizontal direction;
An image combining unit that combines images of a plurality of regions obtained by the radiation detection unit and combines all images of the region of the inspection object;
The radiation detection means is formed in a rod shape extending in the longitudinal direction,
Furthermore, a support member that is formed so that the base end portion is fixed to the adjustment portion that moves integrally with the moving means and is extendable in the vertical direction;
A connecting portion that is disposed at a distal end portion of the support member and rotatably supports a base end portion of the rod-shaped radiation detection means, so that an angle of the radiation detection means with respect to the support member can be adjusted;
The movement of the moving means, the expansion and contraction of the support member, and the angle of the radiation detection means with respect to the support member by the adjustment unit are controlled, and at least the radiation detection means enters or leaves the narrow portion due to the expansion and contraction of the support member. In this case, the angle of the radiation detector with respect to the support member is adjusted so that the support member and the radiation detection means can enter or leave without any trouble, and further, predetermined image composition by the image composition means is controlled. A non-destructive inspection system .
The second aspect of the present invention is:
In the nondestructive inspection system described in the first aspect,
Collimating means that is a cylindrical member that causes radiation emitted from a radiation source to enter and emit as parallel radiation;
And further having other moving means for moving the collimating means in the horizontal direction,
The collimating means is formed in a rod shape extending in a longitudinal direction which is a direction orthogonal to the parallel radiation,
Furthermore, the other end of the support member which is formed to be extendable in the vertical direction by fixing the base end portion to the other adjustment unit that moves integrally with the other moving means,
The other support member is disposed at the distal end portion of the other support member and rotatably supports the base end portion of the rod-like collimator means, so that the angle of the collimator means with respect to the other support member can be adjusted. A connecting portion,
Moreover, the control unit is configured to control movement of the other moving unit, expansion / contraction of the other supporting member, and adjustment of the angle of the collimating unit with respect to the other supporting member by the other adjusting unit. It is in a nondestructive inspection system characterized by that.
The third aspect of the present invention is:
In the nondestructive inspection system described in the first or second aspect,
In the radiation detection means, at least two types of elements having relatively high sensitivity and relatively low sensitivity for detecting the radiation are arranged in a row along the longitudinal direction and formed in a rod shape,
The image synthesizing unit is configured to synthesize an image of a plurality of regions obtained by the radiation detection unit for each image having the same sensitivity and synthesize all images of the region of the inspection object. It is in a nondestructive inspection system.
The fourth aspect of the present invention is:
In the nondestructive inspection system described in the third aspect,
The radiation detecting means is a non-destructive inspection system in which at least two kinds of elements having different sensitivities are alternately arranged along the longitudinal direction.
According to a fifth aspect of the present invention, in the nondestructive inspection system according to any one of the first to fourth aspects,
The radiation detecting means is composed of two rows, and the base end portion of each row is rotatably attached to the connecting portion, and one of the two rows is rotated in the opposite direction. The nondestructive inspection system is configured so as to be able to perform.
The sixth aspect of the present invention is:
In the nondestructive inspection system according to any one of the first to fifth aspects,
The radiation source is in a non-destructive inspection system characterized by a nuclear reactor.
The seventh aspect of the present invention is
In the nondestructive inspection system according to any one of the first to fifth aspects,
In the nondestructive inspection system, the radiation source is a cooling water of a pipe through which the cooling water of the reactor flows, and the inspection object is a pipe other than the pipe through which the cooling water flows. .

  According to the present invention, the radiation emitted from the radiation source originally present in the radioactive atmosphere is incident directly on the predetermined region of the inspection object in parallel or collimating means without collimating means, so that no special radiation source is prepared. It is possible to use a radiation source that is originally present as a radiation source for non-destructive inspection. At the same time, since the collimating means arranges the radiation in parallel, the influence of the radiation irradiated in all directions in the radiation atmosphere can be reduced as much as possible, and a good image of the inspection object by the transmitted radiation can be obtained.

It is explanatory drawing which shows notionally the nondestructive inspection system which concerns on embodiment of this invention. It is the schematic which shows the nondestructive inspection system which concerns on 1st Example of this invention. It is a schematic perspective view which shows the 1st Example of this invention in the state at the time of the operation | movement. It is the schematic which shows the movement locus | trajectory of the radiation selection means in 1st Example of this invention. It is the schematic which shows the nondestructive inspection system which concerns on the 2nd Example of this invention. It is explanatory drawing which shows the relationship between the whole area | region of the image used as the test object with respect to a detection target object, and the area | region of the image which can be taken with one shot. It is a figure which shows the actual radiograph of the detection target shown in FIG. 6, (a) is a case where a sensitivity is low, (b) is a case where a sensitivity is high. It is the schematic which shows the nondestructive inspection system shown in the 3rd Example of this invention. It is a schematic front view which extracts and expands and shows the radiation detection part shown in FIG. It is a schematic perspective view which shows the aspect at the time of inserting the radiation detection part shown in FIG. 8 in the space above a narrow part. It is a schematic perspective view which shows the state at the time of operation | movement of the nondestructive inspection system shown in FIG. It is an enlarged view of the nondestructive inspection system shown in FIG. 8, (a) is the front view, (b) is the top view. It is a schematic front view which extracts and expands and shows the radiation detection part of the nondestructive inspection system which concerns on 4th Example of this invention. It is a schematic front view which expands and shows the radiation detection part of the nondestructive inspection system which concerns on the 5th Example of this invention. It is explanatory drawing which shows notionally the nondestructive inspection system which concerns on a prior art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram conceptually showing an embodiment of the present invention. As shown in the figure, the nondestructive inspection system uses a nuclear reactor 1 which is a fixed facility as a radiation source, and the inside of the reactor containment vessel 3 which is a closed space in the vicinity of the nuclear reactor 1. The piping installed in the inspection object 6 is used.

  Here, the collimator 8 is a cylindrical member that causes the radiation 7 emitted from the nuclear reactor 1 to enter and emit as parallel radiation 7A. The collimator 8 is formed in a cylindrical shape with a material having radiation shielding properties such as lead, and its axis is directed to a region to be inspected by the inspection object 6. Here, the shape of the collimator 8 may be a cylindrical shape, and is not limited to a cylindrical shape. Further, it is desirable that the cross-sectional shape of the collimator 8 be the most rational shape (a shape that allows a larger dose of radiation to be incident) according to the shape of the light receiving surface of the radiation detector 5.

  The radiation detector 5 detects the radiation 7A that has passed through a predetermined region of the inspection object 6 via the collimator 8, and is configured to capture a radiation image of the inspection object 6 in real time. The radiation detector 5 can be suitably configured with a radiation image sensor camera or a flat panel.

  Here, the radiation detector 5 may be configured to scan in such a manner that a predetermined region of the inspection object 6 is divided into a plurality of images by moving in the horizontal direction, the vertical direction, or the horizontal direction and the vertical direction. In this case, since the radiation detector 5 itself can be downsized, it is suitable for the inspection of the inspection object 6 located in a narrow place such as piping of a nuclear facility. When scanning the inspection object 6 with the radiation detector 5, the collimator 8 and the radiation detector 5 are synchronized so that the reactor 1, which is the radiation source, the axis of the collimator 8, and the radiation detector 5 are aligned. The configuration is such that the periphery of the inspection object 6 is moved. Details of the divided image capturing and scanning mechanism will be specifically described in each embodiment.

  The radiation source need not be limited to the nuclear reactor 1, and is sufficient to be able to be detected by the radiation detector 5 through the inspection object 6 disposed in a closed space such as in the reactor containment vessel 3. Any device that emits a large amount of radiation can be used. In addition, for example, cooling water of piping through which the cooling water of the nuclear reactor 1 flows can be used as a radiation source.

  According to this embodiment, the radiation 7 irradiated using the nuclear reactor 1 as a fixed facility as a radiation source can be collimated by the collimator 8 to obtain parallel radiation 7A. Therefore, an image of the transmission region is obtained by the radiation detector 5 by irradiating the inspection object 6 with the radiation 7A and transmitting the predetermined region.

  When a sufficient dose of radiation is obtained from the radiation source, it is not always necessary to collimate the radiation with the collimator 8. However, it is of course preferable to collimate with the collimator 8 in order to obtain a high-quality image.

  Next, examples in which the above embodiment is further embodied will be described. In the following embodiments, the same parts are denoted by the same reference numerals, and redundant description is omitted.

<First embodiment>
FIG. 2 is a schematic view showing a nondestructive inspection system according to the first embodiment. Although the radiation source is not shown in the figure, the place where the non-destructive inspection system is installed is a radioactive atmosphere in which cooling water flowing through the reactor or piping, for example, inside the reactor containment vessel can be used as the radiation source. It has become.

  As shown in FIG. 2, the nondestructive inspection system according to the present embodiment includes a collimating unit 10, an imaging unit 20 having a function of receiving a radiation collimated by the collimating unit 10 and imaging a part of an inspection object. The control unit 30 connected to each of the collimating unit 10 and the imaging unit 20 to control the collimating unit 10 and the imaging unit 20 and a partial image of the inspection object obtained by connecting to the imaging unit 20 are combined. And an image composition unit 40 for obtaining an image of the entire inspection object.

  The collimator unit 10 expands and contracts a collimator 8 that is a cylindrical member that emits incident radiation as parallel radiation, and a rod-shaped member 12 connected to the collimator 8, thereby setting the vertical position (height) of the collimator 8. The collimator 8 can be freely arranged in a three-dimensional manner. The collimator 8 includes a support portion 13 that can be adjusted and a moving means 15 that is provided below the support portion 13 and moves in the horizontal direction. ing. The collimator 8 is miniaturized to such an extent that it can enter the narrow part of the structure.

  The rod-shaped member 12 is not particularly limited as long as it can hold the collimator 8, and the support portion 13 can adjust the position of the collimator 8 in the vertical direction by expanding and contracting the rod-shaped member 12 in the vertical direction. If there is no particular limitation.

  The moving means 15 is not particularly limited as long as it can freely move the collimator 8, the rod-shaped member 12 and the support portion 13 placed on the upper part in the horizontal direction. The moving means 15 of this embodiment includes a plurality of rollers 16 and driving means (not shown) for driving the rollers 16.

  On the other hand, the imaging unit 20 is connected to the radiation detector 5, which is a radiation camera that receives X-rays transmitted through a part of the inspection object and converts the X-rays into corresponding electrical signals. A support portion 23 that can adjust the vertical position (height) of the radiation detector 5 by expanding and contracting the rod-shaped member 22, a roller 26 that is provided below the support portion 23 and moves in the horizontal direction, and The radiation detector 5 can be freely arranged in a three-dimensional manner by a moving means 25 comprising a driving means (not shown) for driving this. These bar-shaped member 22, support portion 23, and moving means 25 constitute a scanning means.

  The radiation detector 5 is not particularly limited as long as it is small enough to enter the narrow part of the structure and can detect the radiation and convert the radiation into a corresponding electrical signal. Examples of the radiation detector 5 include a combination of a scintillator and a CCD camera. The radiation detector 5 configured as described above is characterized by being small and lightweight. Therefore, since it is possible to prevent the rod-shaped member 22 from being bent by using such a small and light radiation detector 5, an image of a part of the inspection object can be obtained more accurately.

  The control unit 30 controls the operations of the collimating unit 10 and the imaging unit 20. Although details will be described later, specifically, when imaging a part of the inspection object, the collimator unit 10 and the imaging so that the axis of the collimator 8 and the radiation detector 5 are aligned at a predetermined distance on a straight line. The collimator 10 and the imaging unit 20 are controlled so that the position of the unit 20 is controlled and the collimator 8 and the radiation detector 5 are moved after the part of the inspection object is imaged and the other part of the inspection object is imaged. Control the position of the.

  Here, the method of controlling the collimator 8 and the radiation detector 5 to maintain the predetermined positional relationship as described above when imaging a part of the inspection object is not particularly limited. For example, the control unit 30 performs control as described below. First, Cartesian coordinates with a certain point as a reference point are set, and in the Cartesian coordinates, the distance that the collimating unit 10 and the imaging unit 20 are moved in the horizontal direction, the rod-shaped member 12 of the collimating unit 10 and the rod-shaped member of the imaging unit 20 Based on the length in the state where 22 is expanded and contracted, the coordinates at which each of the collimator 8 and the radiation detector 5 is located are obtained. Next, the distance between the collimator 8 and the radiation detector 5 is calculated from these coordinates, and the moving means 15 and 25 and the support portions 13 and 23 are controlled so that the distance becomes the above-described predetermined interval. Further, a laser distance measuring device or the like is attached to the collimator 8 and the radiation detector 5, and the distance between the collimator 8 and the radiation detector 5 is measured using the laser distance measuring device, and the moving means so that the distance becomes the above-described predetermined interval. 15 and 25 and the support portions 13 and 23 may be controlled. The control unit 30 is not particularly limited as long as it can perform such control, and examples thereof include a general personal computer and a dedicated computer.

  The image composition unit 40 can synthesize an image of the entire inspection object by combining a plurality of electrical signals corresponding to a part of the image of the inspection object converted by the radiation detector 5. Specifically, the image composition unit 40 superimposes some images of adjacent inspection objects so that there is no overlapping region, and finally combines the images of the entire inspection object. Here, the method for synthesizing the image of the entire inspection object is not particularly limited, and various existing methods can be used. The image composition unit 40 is not particularly limited as long as it has such a function, and may be a general personal computer or a dedicated computer, and may also function as the control unit 30. .

  Next, an aspect when inspecting an inspection object in a space communicating with a narrow portion of a structure using the nondestructive inspection system according to the present embodiment will be described in detail with reference to FIG. FIG. 3 is a schematic perspective view showing an operating state when inspecting an inspection object in a space communicating with a narrow portion of a structure using the nondestructive inspection system according to the present embodiment.

  As shown in FIG. 3, a columnar inspection object 100 to be inspected is arranged in a space above a narrow portion 210 formed between two obstacles 200. Although not shown, an inspection apparatus or the like can be brought close to the inspection object 100 only from the narrow portion 210 side. Therefore, in this embodiment, the collimator 8 and the radiation detector 5 are arranged in the space through the narrow portion 210 so as to sandwich the inspection object 100, and the entire inspection object is described as described below. Get the image.

  First, the collimator 8 and the radiation detector 5 are moved to a position where a predetermined part of the inspection object 100 can be imaged, and the part is imaged. In the present embodiment, as shown in FIG. 4, the lower left part of the inspection object 100 is moved to a position where it can be imaged, and the part is imaged. FIG. 4A is a schematic diagram showing a movement locus of the radiation detector 5 when viewed from the radiation detector 5 side, and FIG. 4B is a diagram of the collimator 8 and the radiation detector 5 when viewed from above. It is the schematic which shows a movement locus | trajectory.

  Here, when imaging a part of the inspection object 100, the vertical positions (heights) of the collimator 8 and the radiation detector 5 are equal, and the distance D (see FIG. 3) between them is constant. Furthermore, the light receiving surface 5C of the radiation detector 5 is disposed so as to be perpendicular to the X-rays irradiated through the collimator 8. Similarly, in the following operations, when imaging, the collimator 8 and the radiation detector 5 have the same vertical position (height), the distance D between them is constant, and the radiation detector 5 The light receiving surface 5C is adjusted to be perpendicular to the X-rays emitted from the collimator 8.

  Next, the collimator 8 and the radiation detector 5 are moved to a position where another part of the inspection object 100 can be imaged. In this embodiment, the collimator 8 and the radiation detector 5 are translated upward by l1 shown in FIG. When the collimator 8 and the radiation detector 5 are moved, they may be moved at the same time, or any one of them may be moved individually. And the part is imaged.

  Here, in the present embodiment, when the collimator 8 and the radiation detector 5 image a part of the inspection object 100, as described above, the collimator 8 and the radiation detector 5 are positioned in the vertical direction (height). ) Are equal, the distance between them is constant, and the light receiving surface 5C of the radiation detector 5 is arranged so as to be perpendicular to the X-rays emitted from the collimator 8, so that the radiation detector 5 Each of the obtained partial images of the inspection object 100 is irradiated from the collimator 8 that is always arranged at the same distance from the radiation detector 5 from the vertical direction with respect to the light receiving surface 5C of the radiation detector 5. It will be obtained by receiving the radiation. Therefore, an image of the entire inspection object 100 obtained by synthesizing a part of the images of the inspection object 100 is a plate-like X-ray source arranged at a certain distance along the inspection object 100. Is equivalent to that obtained by receiving X-rays irradiated in the direction perpendicular to the light receiving surface 5C. As a result, an accurate image of the entire inspection object 100 can be obtained.

  Thereafter, the control unit 30 determines whether or not the entire inspection object 100 has been imaged. If the entire inspection object 100 is not imaged, the above-described operation is performed until the entire inspection object 100 is imaged. Repeated. In the course of performing such a series of scans, it is necessary to move the collimator 8 and the radiation detector 5 to a position where another part of the inspection object 100 can be imaged. Examples of the movement order are l2 to l7 shown in 4 (a) and FIG. 4 (b). By moving in this way, an image of the entire inspection object 100 can be efficiently obtained.

  When the entire inspection object 100 is imaged, the image synthesis unit 40 combines the images of the entire inspection object 100.

  As described above, according to the nondestructive inspection system according to the present embodiment, a part of the inspection object 100 is imaged using the small radiation detector 5 and finally combined to be inspected. Since the entire image of the object 100 can be obtained, the entire inspection object 100 arranged in the space communicating with the narrow portion 210 of the structure can be imaged, and an accurate image of the entire inspection object 100 can be obtained. Can be obtained.

<Second embodiment>
FIG. 5 is a schematic view showing a nondestructive inspection system according to the second embodiment. As shown in the figure, in the nondestructive inspection system according to the present embodiment, the radiation detector 5 is formed by radiation detectors 5A and 5B that capture a predetermined image with two types of sensitivity, low sensitivity and high sensitivity. is there. On the other hand, the collimator 10 is also provided with two collimators 8A and 8B corresponding to the radiation detectors 5A and 5B. As described above, it is not essential to provide the collimators 8A and 8B in correspondence with the radiation detectors 5A and 5B. However, by providing the collimators 8A and 8B as described above, the shape of the light receiving surface of the radiation detectors 5A and 5B is obtained. The radiation can be collimated most rationally to match each other.

  As a result, the imaging unit 21 receives the radiation collimated by the collimators 8A and 8B of the collimator unit 10 and transmitted through a part of the inspection object 100, and converts the radiation into electrical signals corresponding to the radiation dose. It has detectors 5A and 5B. The two radiation detectors 5A and 5B are integrally supported by the rod-like member 22, and the rod-like member 22 is expanded and contracted so that the vertical position (height) of the radiation detectors 5A and 5B is supported by the support member. 23, and is moved in the horizontal direction by the moving means 25 via a roller 26 provided below the support portion 23 and driven by a driving means (not shown). Also in the present embodiment, as in the first embodiment, the rod-shaped member 22, the support portion 23, and the moving means 25 form a scanning means, and the radiation detectors 5A and 5B are integrated by combining these movements. The radiation detectors 5 </ b> A and 5 </ b> B scan the entire predetermined inspection area of the inspection object 100 by moving them horizontally and vertically. The scanning trajectory at this time is indicated by an arrow 101 in FIG. At this time, the collimators 8A and 8B are also configured to move in synchronization with the radiation detectors 5A and 5B.

  Here, the radiation detectors 5A and 5B are not particularly limited as long as they can image the inspection object 100 in real time. However, as in the first embodiment, a scintillation CCD camera, an X-ray image intensifier. It can be suitably configured with a flat panel X-ray sensor or the like. In addition, the radiation detectors 5A and 5B are configured so as to respectively image a part of the inspection region of the inspection object 100 with two types of sensitivity of relatively low sensitivity and high sensitivity. There are no special restrictions. For example, in the case of a camera, the sensitivity can be easily adjusted by changing the shutter time. The sensitivity can be adjusted by using radiation detectors 5A and 5B having low sensitivity and high sensitivity. For example, when a CCD is used as an element, it can be easily adjusted by changing the thickness of the element. Furthermore, the sensitivity can be adjusted by adjusting the gains of the radiation detectors 5A and 5B.

  The functions of the control unit 30 and the image composition unit 40 in this embodiment are not essentially different from those in the first embodiment. However, the control unit 30 in the present embodiment combines a plurality of images individually obtained by the two radiation detectors 5A and 5B and combines one image with low sensitivity and high sensitivity corresponding to a predetermined region of the inspection object 100. Control is performed so that each image is obtained.

  FIG. 6 is an explanatory diagram showing the relationship between the entire area of the image to be inspected for the detection object (elbow) 100 and the area of the image that can be taken with one shot. A region 102 indicated by a thick dotted line in the drawing is combined with a one-shot region 103 indicated by a thin dotted line in the drawing to be combined into one image. Images of each one-shot region 103 are picked up by the radiation detectors 5A and 5B by scanning as described above. FIG. 7 shows an actual X-ray photograph of the inspection object (elbow) shown in FIG. 6 obtained as a result. FIG. 7A shows a case where the sensitivity is low (shooting time 40 seconds), and FIG. 7B shows a case where the sensitivity is high (shooting time 60 seconds). When the sensitivity is low as shown in FIG. 7A, the entire shape is clearly grasped, and when the sensitivity is shown in FIG. 7B, the boundary between the thin portion and the thick portion is clearly grasped. You can see that

<Third embodiment>
FIG. 8 is a schematic view showing a nondestructive inspection system according to the third embodiment. As shown in the figure, in the nondestructive inspection system according to the present embodiment, radiation detectors 51A and 51B that capture a predetermined image with two types of sensitivity, low sensitivity and high sensitivity, as in the second embodiment. The radiation detector 51 is formed. Further, the radiation detectors 51A and 51B divided into two groups of relatively low sensitivity and high sensitivity are formed in a rod shape, and radiation capable of capturing an image in real time in the center in the width direction. A plurality of CdTe elements 511 serving as detection sensors are arranged in a row along the longitudinal direction. Specifically, a plurality of CdTe elements 511 are arranged in a line along the longitudinal direction at the center in the width direction of the radiation detectors 51A and 51B.

  Here, the radiation detectors 51A and 51B are small enough to be inserted into the narrow part of the structure, and the X-rays are detected in real time to correspond to an image of a part of the inspection object. There is no particular limitation as long as it can be converted into a signal. In addition, the length of the longitudinal direction of radiation detector 51A, 51B can be set arbitrarily.

  The connecting portion 24 is provided between the radiation detectors 51A and 51B and the rod-shaped member 22 and is configured so that the angle of the radiation detectors 51A and 51B with respect to the rod-shaped member 22 can be adjusted.

  As shown in FIG. 9, the connection unit 24 is not particularly limited as long as it can rotate the radiation detectors 51 </ b> A and 51 </ b> B as the rotation shafts of the radiation detectors 51 </ b> A and 51 </ b> B. As the connection unit 24, for example, the radiation detectors 51A and 51B are connected to the rod-shaped member 22, and the radiation detectors 51A and 51B are rotated by driving means such as a drive motor (not shown) to detect the radiation detector for the rod-shaped member 22. Examples include a universal joint that can freely change the angles of 51A and 51B.

  On the other hand, the collimator 8 in the present embodiment has a cross-sectional shape corresponding to the rod shape formed by the radiation detectors 51A and 51B, and the collimator 8 has a connection portion having the same mechanism as the connection portion 24 shown in FIG. 14 is connected to the rod-shaped member 12 via 14. As a result, by adjusting the angle of the collimator 8 with respect to the rod-shaped member 12 according to the angle of the radiation detectors 51A and 51B with respect to the rod-shaped member 22, the collimated radiation is irradiated in an optimum state toward the radiation detectors 51A and 51B. can do.

  The functions of the control unit 30 and the image composition unit 40 in the present embodiment are not essentially different from those in the first embodiment. However, the control unit 30 in this embodiment also performs control to rotate the connection unit 24 so that the radiation detectors 51A and 51B form a predetermined angle with respect to the rod-shaped member 22, and the rod-shaped member 22 is synchronized with this. Control is also performed to rotationally drive the connecting portion 14 so that the collimator 8 makes a predetermined angle with respect to the member 12.

  Next, referring to FIG. 10 to FIG. 12, the operation when inspecting a predetermined area of the inspection object in the space communicating with the narrow portion of the structure using the nondestructive inspection system according to the present embodiment will be described. Further details will be described. Here, FIG. 10 is a schematic perspective view showing a state when the imaging unit in this embodiment is inserted into the space above the narrow portion, and FIG. 11 is a diagram of the structure using the nondestructive inspection system according to this embodiment. It is a schematic perspective view which shows the state at the time of operation | movement at the time of test | inspecting the test target object in the space connected to the narrow part. 12 is an enlarged view of the nondestructive inspection system shown in FIG. 8, wherein (a) is a front view thereof and (b) is a top view thereof.

  First, as shown in FIG. 10, a columnar inspection object 100 to be inspected is arranged in a space above a narrow portion 210 formed between two obstacles 200. Here, although not shown, the inspection object 100 can be accessed only from the narrow portion 210 side. Therefore, in this embodiment, the radiation detectors 51A and 51B of the imaging unit 50 are arranged in the space through the narrow portion 210 so as to sandwich the inspection object 100, and the inspection is performed as described below. An image of a predetermined area of the object 100 is obtained.

  First, the radiation detector is configured so that the angle formed by the radiation detectors 51A and 51B and the rod-shaped member 22 is 180 °, that is, the longitudinal direction of the radiation detectors 51A and 51B and the longitudinal direction of the rod-shaped member 22 are matched. 51A and 51B are rotated, and the radiation detectors 51A and 51B are inserted into the narrow part 210 from below in this state. At this time, the radiation detectors 51 </ b> A and 51 </ b> B and the rod-shaped member 22 are arranged in a straight line, so that they can easily pass through the narrow portion 210. At this time, the collimator 8 is also in the same posture.

  Then, when the radiation detectors 51A and 51B are occupied in the space above the narrow portion 210, the radiation detectors 51A and 51B are arranged so that the radiation detectors 51A and 51B make a predetermined angle with respect to the rod-shaped member 22. Rotate. In the present embodiment, as shown in FIG. 11, the radiation detectors 51A and 51B are rotated so that the angle formed by the rod-shaped member 22 and the radiation detectors 51A and 51B is 90 °. At this time, the collimator 8 is also rotated through the connecting portion 14 so as to have the same posture. As a result, the collimator 8 can irradiate the radiation collimated in an optimum state toward the radiation detection units 51A and 51B.

  Here, for example, when the imaging unit 50 having the radiation detectors 5A and 5B shown in the second embodiment attached to the end of the rod-like member 22 is used, the imaging unit 50 is shown in FIGS. 12 (a) and 12 (b). As described above, only the region R <b> 2 of the inspection object 100 that is located immediately above the narrow portion 210 and has a width corresponding to the width W of the narrow portion 210 can be imaged.

  On the other hand, when the imaging unit 50 of the present embodiment is used, as described above, the radiation detectors 51A and 51B are rotated so that the angle of the radiation detectors 51A and 51B with respect to the rod-shaped member 22 is 90 °. Thus, the radiation detectors 51A and 51B can be positioned at positions where the region R1 adjacent to the region R2 of the inspection object 100 can be imaged. As a result, although details will be described later, in addition to the region R2 of the inspection object 100, the region R1 of the inspection object 100 that could not be imaged by the imaging units 20 and 21 according to the first and second embodiments was imaged. Will be able to.

  In this state, a part of the region R1 is imaged by irradiating the inspection object 100 with radiation emitted from a radiation source such as a nuclear reactor and collimated by the collimator 8. In the present embodiment, as shown in FIG. 12A, a part of the inspection object 100 below the region R1 is imaged.

  Next, the radiation detectors 51A and 51B are moved to a position where another part of the region R1 of the inspection object 100 can be imaged. In the present embodiment, as shown in FIG. 12A, the radiation detectors 51A and 51B are slightly translated upward. When the radiation detectors 51A and 51B are moved, they may be moved at the same time, or any one of them may be moved individually. And a predetermined part is imaged.

  Here, when a part of the inspection object 100 is imaged, the vertical positions (heights) of the collimator 8 and the radiation detectors 51A and 51B are equal, and the distance between them is D. Further, the positions of the collimator 8 and the radiation detectors 51A, 51B are adjusted so that the longitudinal direction of the radiation detectors 51A, 51B is perpendicular to the direction from the collimator 8 toward the radiation detectors 51A, 51B. Therefore, an accurate image of the region R of the inspection object 100 can be obtained from the image of the region R1 of the inspection object 100 obtained by combining a part of the images of the inspection object 100.

  Thereafter, the control unit 30 determines whether or not the entire area R1 of the inspection object 100 has been imaged. If the entire area R1 of the inspection object 100 has not been imaged, the entire inspection object 100 is imaged. The process described above is repeated.

  On the other hand, when the entire inspection object 100 is imaged, the image synthesis unit 40 synthesizes an image of the entire region R1 of the inspection object 100 for each of low sensitivity and high sensitivity.

  For the region R3 adjacent to the region R2 of the inspection object 100, the radiation detectors 51A and 51B are rotated so that the angle of the radiation detectors 51A and 51B with respect to the rod-shaped member 22 is −90 °. An image of the entire region R3 of the inspection object 100 can be synthesized by imaging and image synthesis.

  As described above, according to the nondestructive inspection system according to the present embodiment, the longitudinal direction of the radiation detectors 51A and 51B and the longitudinal direction of the rod-like member 22 coincide with each other when inserted into the narrow portion 210. Thus, by rotating the radiation detectors 51A and 51B, the radiation detectors 51A and 51B are passed through the narrow portion 210 in a state of being held in a posture extending from the rod-shaped member 22, and the radiation detectors 51A and 51B Since the radiation detectors 51A and 51B can be rotated so that the angle of the radiation detectors 51A and 51B with respect to the rod-shaped member 22 is 90 ° after the 51B is occupied in the space above the narrow portion 210, With respect to the inspection object 100 in the space communicating with the narrow portion 210, the regions R1 and R3 other than the region R2 of the inspection target 100 corresponding to the narrow portion 210 are imaged. Rukoto can.

<Fourth embodiment>
FIG. 13 is a schematic front view showing an extracted and enlarged radiation detector of the nondestructive inspection system according to the fourth embodiment of the present invention. In this embodiment, the arrangement of the elements of the radiation detectors 51A and 51B shown in FIGS. 8 and 9 is changed. That is, the whole is formed in a rod shape by alternately arranging the low-sensitivity elements constituting the radiation detector 51A and the high-sensitivity elements constituting the radiation detector 51B. Note that, in order to avoid complications, the reference numerals in the figure omit “51” of the radiation detectors 51A and 51B, and indicate only “A” and “B”. That is, “A” represents 51A and “B” represents 51B.

  According to this embodiment, in the first scan, the radiation detectors 51A and 51B are moved in the vertical direction in the state shown in FIG. 13A to image a predetermined region of the inspection object. Next, in the second scanning, as shown in FIG. 13B, the radiation detectors 51A and 51B are similarly moved in the vertical direction at the position horizontally moved by one pitch d of the element in the right direction in the figure. Then, an image of an area shifted by one pitch d of the inspection object is taken.

  As a result, if the odd-numbered row of the first scanning image and the even-numbered row of the second scanning image are selected and synthesized, a low-sensitivity image can be obtained, and the even-numbered row of the first scanning image and the second scanning image High-sensitivity images can be obtained by selecting and synthesizing odd columns.

<Fifth embodiment>
FIG. 14 is a schematic front view showing an extracted and enlarged radiation detector of the nondestructive inspection system according to the fifth embodiment of the present invention. In this embodiment, another set of radiation detectors 51A and 51B shown in FIGS. 8 and 9 is added. That is, the radiation detectors 61A and 61B and the radiation detectors 62A and 62B of the imaging unit 60 are two rod-shaped members arranged in parallel in the same direction as the rod-shaped member 22, and the radiation detectors 61A and 61A, respectively. 62A is formed for low sensitivity, and radiation detectors 61B and 62B are formed for high sensitivity. Each of the radiation detectors 61A and 61B and the radiation detectors 62A and 62B is configured by arranging a plurality of CdTe elements 611 in a row along the longitudinal direction, and is driven through the respective base end portions by driving the connection portions 64. And can be rotated. That is, the radiation detectors 61A and 61B and the radiation detectors 62A and 62B are connected by the connection unit 64 based on the control of the control unit 30 so that the longitudinal directions of the radiation detectors 61A and 61B and the radiation detectors 62A and 62B are both horizontal. It can be rotated independently.

  By configuring such an imaging unit 60, first, the radiation detectors 61A and 61B and the radiation detectors 62A and 62B, which are in the form of rods extending vertically upward on the extension of the axis of the rod-shaped member 22, are moved clockwise and respectively. It can be rotated horizontally counterclockwise to open horizontally. As a result, a wider area of the inspection object 100 in the space above the narrow portion 210 can be imaged at a time, and an image of the entire predetermined area of the inspection object 100 can be obtained more efficiently. .

  In the case of this embodiment as well, the element arrangement of the radiation detectors 61A, 61B, 62A, and 62B can be configured in the same manner as in the fourth embodiment shown in FIG. In this case, imaging similar to that in the fourth embodiment can be performed on both the left and right sides of the connection portion 64.

<Other embodiments>
In the third embodiment, the imaging unit 50 is divided into the low sensitivity and the high sensitivity, but it is not always necessary to separate in this way. A nondestructive inspection system useful for inspection of a narrow portion can be constructed only by forming the radiation detector in a rod shape as in the third embodiment. In this case, the collimator 8 may not always be necessary.

  In the above-described embodiment, the CdTe elements 511 and 611 are described as examples of the components such as the radiation detectors 51A and 51B. However, the present invention is not limited to this. The radiation detectors 51A, 51B and the like are not particularly limited as long as they can detect radiation in real time and image the inspection object 100. For example, the radiation detectors 51A, 51B, 61A, 61B, 62A, 62B are a combination of a scintillator made of CsI and a CCD camera arranged in the longitudinal direction of the radiation detectors (51A, 51B) to (62A, 62B). You may arrange in a shape.

  Furthermore, in the said Example, although the length of the longitudinal direction of the radiation detectors (51A, 51B) thru | or (62A, 62B) was constant, this may be extendable. For example, if the length in the longitudinal direction of the radiation detectors (51A, 51B) to (62A, 62B) can be increased, the area R1 of the inspection object 100 that can be imaged can be increased. .

  In the said Example, although the angle of the radiation detectors (51A, 51B) thru | or (62A, 62B) with respect to the rod-shaped member 22 was changed using the connection parts 24 and 64, it is not limited to this. For example, a bendable member is provided between the support member and these components, and the angle of the radiation detectors (51A, 51B) to (62A, 62B) with respect to the rod-shaped member 22 is changed by bending the member. You may do it.

  In the present invention, any radiation can be used as long as it is radiation emitted from a radiation source. That is, not only X rays and γ rays but also neutron rays can be used.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used in an industrial field where maintenance and inspection of a nuclear reactor that needs to diagnose a facility having a radioactive ray atmosphere is required.

DESCRIPTION OF SYMBOLS 1 Reactor 3 Reactor containment vessel 5, 5A Radiation detector 7, 7A Radiation 8, 8A Collimator 20, 21, 50, 60 Imaging part 51A, 51B, 61A, 61B, 62A, 62B Radiation detector 30 Control part 40 Image Compositing part

Claims (7)

Non-destructive to the inspection object that has a radiation source that is a fixed facility that irradiates radiation or a radiation source that irradiates radiation by contacting this facility in the vicinity and is installed in a closed space An inspection system ,
Radiation detection means for detecting radiation irradiated from any of the radiation sources and transmitted through a predetermined region of the inspection object;
Moving means for moving the radiation detecting means in a horizontal direction;
An image combining unit that combines images of a plurality of regions obtained by the radiation detection unit and combines all images of the region of the inspection object;
The radiation detection means is formed in a rod shape extending in the longitudinal direction,
Furthermore, a rod-like support member formed so that a base end portion is fixed to an adjustment portion that moves integrally with the moving means and is extendable in the vertical direction;
A connecting portion that is disposed at a distal end portion of the support member and rotatably supports a base end portion of the rod-shaped radiation detection means, so that an angle of the radiation detection means with respect to the support member can be adjusted;
The movement of the moving means, the expansion and contraction of the support member, and the angle of the radiation detection means with respect to the support member by the adjustment unit are controlled, and at least the radiation detection means enters or leaves the narrow portion due to the expansion and contraction of the support member. In this case, the angle of the radiation detector with respect to the support member is adjusted so that the support member and the radiation detection means can enter or leave without any trouble, and further, predetermined image composition by the image composition means is controlled. non-destructive inspection system, characterized by a control unit for. In the nondestructive inspection system according to claim 1,
Collimating means that is a cylindrical member that causes radiation emitted from a radiation source to enter and emit as parallel radiation;
And further having other moving means for moving the collimating means in the horizontal direction,
The collimating means is formed in a rod shape extending in a longitudinal direction which is a direction orthogonal to the parallel radiation,
Furthermore, the other end of the support member which is formed to be extendable in the vertical direction by fixing the base end portion to the other adjustment unit that moves integrally with the other moving means,
The other support member is disposed at the distal end portion of the other support member and rotatably supports the base end portion of the rod-like collimator means, so that the angle of the collimator means with respect to the other support member can be adjusted. A connecting portion,
Moreover, the control unit is configured to control movement of the other moving unit, expansion / contraction of the other supporting member, and adjustment of the angle of the collimating unit with respect to the other supporting member by the other adjusting unit. A non-destructive inspection system . In the nondestructive inspection system according to claim 1 or 2,
In the radiation detection means, at least two types of elements having relatively high sensitivity and relatively low sensitivity for detecting the radiation are arranged in a row along the longitudinal direction and formed in a rod shape,
The image synthesizing unit is configured to synthesize an image of a plurality of regions obtained by the radiation detection unit for each image having the same sensitivity and synthesize all images of the region of the inspection object. Non-destructive inspection system. In the nondestructive inspection system according to claim 3,
The non-destructive inspection system , wherein the radiation detecting means includes at least two types of elements having different sensitivities arranged alternately along the longitudinal direction . In the nondestructive inspection system according to any one of claims 1 to 4 ,
The radiation detecting means is composed of two rows, and the base end portion of each row is rotatably attached to the connecting portion, and one of the two rows is rotated in the opposite direction. A non-destructive inspection system characterized in that it is configured to be able to perform. In the nondestructive inspection system according to any one of claims 1 to 5,
A non-destructive inspection system characterized in that the radiation source is a nuclear reactor . In the nondestructive inspection system according to any one of claims 1 to 5 ,
The non-destructive inspection system , wherein the radiation source is cooling water of a pipe through which a cooling water of the reactor flows, and the inspection object is a pipe other than the pipe through which the cooling water flows .