JPH075455Y2 - Fiber optic scope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The optical fiber scope according to the present invention is used when observing a nuclear reactor portion of a nuclear power plant from the outside.

(Prior Art) In a nuclear power plant, in order to inspect the presence of scratches on the fuel rods existing in the core part of the nuclear reactor, or to inspect whether there is foreign matter in the core part, Is observed with an optical fiber scope.

Thus, when observing the core portion with an optical fiber scope, it is performed as shown in FIG. 7, for example.

In FIG. 7, 1 and 1 are fuel rods having a plurality of vertical positions bundled by spacers 2 and 2, and 3 is an optical fiber scope for observing the fuel rods 1 and 1. 3 is a lifting mechanism 4 in the Z-axis direction,
The first horizontal moving mechanism 5 is movable in the X-axis direction, and the second horizontal moving mechanism 6 is movable in the Y-axis direction.

The optical fiber scope 3 for observing the core is provided in the core portion so as to be freely movable in the three-dimensional direction by the above-mentioned mechanism. Therefore, while moving the optical fiber scope 3 in an appropriate direction, the fuel rod By observing the surfaces of the fuel cells 1, 1 and the spacers 2, 2, it is possible to inspect whether or not the fuel rods 1, 1 are damaged or whether there is any foreign matter in the core portion.

The optical fiber scope 3 used in such a case has an image guide or a light guide, each of which is made by bundling a large number of optical fibers, inserted inside a stainless steel tube. An opening is provided on the side surface of the distal end portion of the tube, and a prism is arranged at a portion aligned with this opening. As such an optical fiber scope 3, a structure having a structure as shown in FIGS. 8 to 11 has been conventionally known.

Of these, the first example shown in FIGS.
-154225 gazette, etc., four sets of scope elements 7a, 7b, 7c, 7d, the outer peripheral surface of each other abutting,
It is composed by combining them into a sheet. Each scope element 7a, 7b, 7c, 7d has one image guide 9a, 9b, 9c, 9d and two light guides 8a,
It is sandwiched between 8b, 8c, and 8d. The scope elements 7a, 7b, and 7c in this are observable on the side (front side in FIG. 9) of the optical fiber scope 3, and the remaining scope elements 7d are light guides. By displacing the tip portions of 8d and 8d and the tip portion of the image guide 9d in a stepwise manner, the lower side of the optical fiber scope 3 (lower side in FIG. 9) can be observed.

Further, the optical fiber scope 3 shown in FIGS. 10 to 11 is composed of only the scope element 7d.

(Problems to be solved by the invention) However, in the case of the conventional optical fiber scope, there were the following problems in observing the core of the nuclear reactor.

That is, when inspecting the fuel rods 1 and 1 for scratches,
Since the part into which the optical fiber scope 3 should be inserted is fixed and the part where scratches are likely to occur is almost fixed,
Although it does not cause any particular problems, for example, when the metal powder generated by the damage of the pump for circulating the core cooling water mixes with the primary cooling water and enters the core, in which part of the core the metal powder exists Since it is not known at all, the optical fiber scope 3 must be introduced into every part of the core.

In this way, when the optical fiber scope 3 is made to enter a portion other than the fixed portion, the tip of the optical fiber scope 3 should be prevented from hitting an obstacle while observing the insertion direction (forward direction of movement). , Fiber optic scope 3
It is necessary to observe the presence or absence of foreign matter such as the metal powder while moving the.

On the other hand, the portion where foreign matter may exist, such as the core of a nuclear reactor, is often narrow and deep, so it is necessary to make the optical fiber scope thin and have sufficient rigidity.

However, there has been no optical fiber scope that satisfies all of the above conditions, including the one having the structure shown in FIGS. 8 to 11 described above.

The optical fiber scope of the present invention was conceived in view of such circumstances.

(Means for Solving the Problems) In the optical fiber scope of the present invention, at least one first light guide and one first image guide are combined in a sheet shape by bringing their outer peripheral surfaces into contact with each other. A first scope element, and a second scope element in which at least one second light guide and one second image guide are combined in a sheet shape by bringing their outer peripheral surfaces into contact with each other, The concave portion and the convex portion existing on the side surface of each scope element are fitted to each other so as to be overlapped in a cross-sectional bales shape.

(Operation) In the case of the optical fiber scope of the present invention configured as described above, by observing the front of the optical fiber scope in the moving direction with the first light guide while illuminating the front with the first light guide, there is an obstacle in the front of the moving direction. Check to see if something exists.

In this way, the optical fiber scope is moved while checking whether or not there is an obstacle ahead of the moving direction, and the vicinity of the tip of the optical fiber scope is observed with the second image guide while illuminating it with the second light guide. Then, it is inspected whether or not foreign matter is present in this portion.

In the case of the optical fiber scope of the present invention, the concave and convex portions present on the side surfaces of both the first and second scope elements are fitted to each other so that the two scope elements are superposed in a cross-sectional bales shape. Therefore, the rigidity in the bending direction is improved, and the rigidity of the optical fiber scope can be sufficiently maintained even when the optical fiber scope is made thin.

(Embodiment) Next, the present invention will be described in more detail with reference to the illustrated embodiment.

1 to 5 show a first embodiment of the present invention, FIG. 1 is a side view showing the entire structure, FIG. 2 is an enlarged view of part A of FIG. 1, and FIG. 3 is of FIG. FIG. 4 is a view seen from the left side, FIG. 4 is a view seen from above in FIG. 2, and FIG. 5 is a view seen from below in FIG.

This optical fiber scope includes a direct-viewing scope element 10 (first scope element) for looking forward in the insertion direction and an inspection scope element 11 (second scope element) for observing the side. It is configured by combining, the direct-view scope element 10 at the base end, the direct-view eyepiece 12, the inspection scope element 11 at the base end, the inspection eyepiece 13
Are provided respectively. Further, the tip end portion of the guide tube 20 accommodating the scope elements 10 and 11 is folded back into a U shape so that the optical fiber scope of the present invention enables observation of the deep portion.

Of the two types of scope elements 10 and 11 described above, the direct-view scope element 10 includes one first light guide 14 and one first image guide 15 each having a circular cross-section, and the outer peripheral surfaces thereof contact each other. The first light guide 14 illuminates the front side in the insertion direction (the left side in FIGS. 1 and 2), and the first image guide 15 makes it possible to observe this illuminated portion. ing.

In addition, the scope element 11 for inspection sandwiches one second image guide 16 with two second light guides 17 and 17, and
It is configured by combining the outer peripheral surfaces of each other into a sheet shape. Second image guide above
16 and the second light guide 17, 17 are provided with openings 18, 18 (FIG. 5) on the side surface of the tip of the stainless tube, and are aligned with the openings 18, 18 inside the tip of the stainless tube. A prism 19 (Fig. 2) is provided at a position to be set, and the second light guides 17 and 17 obliquely rearward in the moving direction of the optical fiber scope (lower right of Figs. 1-2).
The second image guide 16 makes it possible to observe this illuminated part.

Direct-viewing scope elements 10 each configured as described above
As shown in FIG. 3, the inspection scope element 11 and the inspection scope element 11 are overlapped with each other by fitting the concave portions and the convex portions present on the side surfaces of the scope elements 10 and 11 to each other so as to have a cross-sectional shape. .

In the case of the optical fiber scope of the present invention configured as described above, by observing the front of the moving direction of the optical fiber scope with the first image guide 15 while illuminating it with the first light guide 14 of the direct-view scope element 10, It is confirmed whether or not there is an obstacle in front of the moving direction of the optical fiber scope (to the left of FIGS. 1, 2, 4, and 5). Therefore, the optical fiber scope can be inserted deep into the core while avoiding obstacles.

When inspecting the core part, move the optical fiber scope while avoiding obstacles while checking whether there is an obstacle ahead of the moving direction as described above, and move the tip of the optical fiber scope. Second image guide while illuminating the vicinity of the part with the second light guide 17, 17 of the inspection scope element 11.
Observe at 16 and inspect for foreign matter in this area.

The optical fiber scope of the present invention is configured as described above,
As described above, in the case of such an optical fiber scope of the present invention, the concave portion and the convex portion existing on the side surface of the direct-viewing scope element 10 and the inspection scope element 11 are fitted to each other. Since the above scope elements 10 and 11 are overlapped in a cross-sectional shape, the rigidity of the optical fiber scope formed by combining the scope elements 10 and 11 is improved in the bending direction, and the optical fiber scope is improved. Even with a thin structure, the rigidity of this optical fiber scope can be sufficiently maintained.

Next, FIG. 6 shows a second embodiment of the present invention.

In the first embodiment described above, the tip portion of the guide tube 20 accommodating two scope elements 10 and 11 for direct viewing and for observation is U-shaped.
In the case of the present embodiment, the tip end of the guide tube 20 remains straight while it is folded back in a letter shape.

Other configurations and operations are similar to those of the above-described first embodiment, but the shape of the first embodiment and the shape of the second embodiment are appropriately selected according to the structure of the portion to be inspected. use.

(Effects of the Invention) Although the optical fiber scope of the present invention is constructed and operates as described above, it is possible to have a structure that is thin and has sufficient rigidity, so that it is as narrow as the core of a nuclear reactor. Moreover, it becomes easy to inspect the deep part.

[Brief description of drawings]

1 to 5 show a first embodiment of the present invention, FIG. 1 is a side view showing the overall construction, FIG. 2 is an enlarged view of part A of FIG. 1, and FIG. 3 is of FIG. FIG. 4 is a view seen from the left side, FIG. 4 is a view seen from above in FIG. 2, and FIG. 5 is a view seen from below in FIG.
FIG. 6 shows a second embodiment of the present invention, which is similar to FIG. 1,
FIG. 7 is a perspective view showing the state of observing the core with an optical fiber scope, and FIGS. 8 to 11 are 2 of a conventional optical fiber scope.
Fig. 8 shows an example, Fig. 8 is a side view of the first example, Fig. 9 is an enlarged view of part B of Fig. 8, Fig. 10 is a side view of the second example, and Fig. 11 is C of Fig. 10. FIG. 1: Fuel rod, 2: Spacer, 3: Optical fiber scope, 4: Lifting mechanism, 5: First horizontal moving mechanism, 6: Second horizontal moving mechanism,
7a, 7b, 7c, 7d: scope element, 8a, 8b, 8c, 8d: light guide, 9a, 9b, 9c, 9d: image guide, 10, 11: scope element, 12: eyepiece for direct view, 13: Inspection eyepiece, 14: first light guide, 15: first image guide, 16: second image guide, 17: second light guide, 18: aperture, 19: prism, 20: guide tube.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-61-292121 (JP, A) JP-A-63-259508 (JP, A) Actually open 61-92902 (JP, U) Actual-open Sho 59- 98401 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. At least one first light guide and 1.
The first scope element in which the first image guides of the book are combined in a sheet shape by bringing their outer peripheral surfaces into contact with each other, and at least one second light guide and one second image guide are The second scope element combined in a sheet shape by bringing the outer peripheral surfaces of the two into contact with each other, and by fitting the concave portion and the convex portion present on the side surface of each scope element to each other, are stacked in a cross-sectional bales shape. Combined optical fiber scope.