JPS5834394A - Guide device of incore remote inspection device - 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 The present invention relates to a guide device for guiding a remote in-core inspection device of a power reactor to the bottom of the reactor.

As part of the inspection during the service life of power reactors, it is required to visually inspect the attachment parts of the reactor internals, which are directly attached to the reactor pressure vessel, to confirm their soundness. This visual inspection is performed by lowering the remote furnace inspection device to a predetermined position at the bottom of the furnace. However, lowering this in-core remote inspection device to a predetermined position quickly and accurately is a very difficult task that requires skill.

This will be explained in detail below using the drawings.

In Fig. 1, among the parts to be visually inspected inside the pressure vessel l, those located below the core support plate are the shroud 3, the control rod drive mechanism (hereinafter referred to as ORD), the tap tube t, and the in-core. These are the welded parts of the guide pipe S, the differential pressure boric acid water injection pipe B, and the lower end plate 7 of the pressure vessel. In order to bring the in-core remote inspection device j closer to these points, K is the fuel assembly near the inspection point, the fuel support fitting lθ
, remove the control rod (not shown), the control rod guide tube 18, and the thermal tube (not shown). Next, using the space created by these removals, the inspection device g is suspended from the operating chamber floor (not shown) installed above the pressure vessel l, and the upper grid plate /2, the core support plate λ, etc. pass through 0
Fix it on the FID housing/3.

It is necessary to quickly lower the inspection device to the CHD housing/3 and lift it up from there. In particular, in order to prevent the performance of the optical system in the detection device g from deteriorating as much as possible due to radiation, it is necessary to quickly pass between the fuel assemblies where radiation is high. However, due to the flow of primary cooling water in the reactor, the inspection device swings and rotates, making it extremely difficult to quickly pass the inspection device through the upper grid plate and the core support plate. Furthermore, in order to perform visual inspection quickly and reliably, inspection equipment t and 0N are required.
Check the inspection device t so that the circumferential position with the tD housing/3 is always constant. However, such control is extremely difficult and requires skill.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a guide device for a remote in-core inspection device that allows the remote in-core inspection device to be quickly and accurately placed in a predetermined position of a CED housing.

For this purpose, the guide device according to the present invention is composed of (3) a guide tube and a skirt portion provided at the upper end of the guide tube to guide an inspection device to the guide tube. The inner surface of the tube is provided with a guide section that guides the inspection device so that it can move only straight in the axial direction of the guide tube, and the outer surface of the guide tube is provided with a hanging section for suspending the guide device from the upper lattice plate. , and a guided portion that is guided by an upper lattice plate so as to be able to move only in a straight line in the axial direction.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, the guide device L is roughly divided into a cylindrical guide tube /S and a skirt portion 16 connected to the upper end of the guide tube 15. As shown in FIG. The length of this guide tube/S is set to be longer than the distance between the upper grid plate 7.2 and the core support plate shown in Fig. 1, and its inner diameter is set to a size that allows it to pass through the inspection device. has been done. Guide tube/! A guide rail is provided on the inner surface of the tube and extends in the longitudinal direction, ie, the axial direction, from the upper end to the lower end of the tube. This guide rail serves as a guide portion that guides the inspection device so that it can only move straight in the axial direction of the guide tube. On the outer surface of the guide tube 15, a square flange-shaped hanging part /g is protruded from the upper part, and guide pipes hang down from the four corners of this square flange hanging part /g, respectively. The lower end of each guide pipe /9 is the guide pipe /! It is bent towards the outside of the These guide pipes /9 act as guided parts that are guided by the upper lattice plate /U so that they can only move straight in the axial direction. The skirt portion /≦ is connected to the upper end of the guide tube /S, and has a shape that opens outward as it goes upward. This skirt part/
A hanging fitting 20 is attached to the upper end of the hanging fitting 20 at a symmetrical position, and a rope rope is tied to the hanging fitting 20.

3 and 3, the in-furnace remote inspection device S has a guide groove n extending in the longitudinal direction on the outer surface of its main body 2, into which the guide rail of the guide tube S can be fitted. The lower end and upper end of this guide groove n have widening portions JJ a *:L3 b in which the groove width increases upward and downward, respectively. The widened portions 23a and 13b allow the guide groove n and the guide rail 17 to fit smoothly. A tip portion protrudes from the lower end of the inspection device main body 12, and this tip portion can be stored within the inspection device main body as required.

Next, we will explain the function of the guide device.

In FIG. 1, is the fuel assembly located near the visual inspection point of the weld between the pressure vessel lower end plate 7 and the C'RD staff tube bow and other various reactor internal structures? , fuel support fitting I
O1 Remove the control rod (not shown), control rod guide tube/c, and thermal tube (not shown).

After this, the guide device/bow shown in Figure 2 is suspended from the operating floor (not shown) by a rope, and the upper lattice plate
lower it onto the surface. The lower end of the guide pipe 15 passes through the upper lattice plate 1, and then the lower end of the guide pipe /7 reaches the upper lattice plate /λ and is fitted into a square guide hole (not shown) provided in the upper lattice plate saw. Guide pipe 17 to this guide hole
By fitting, the guide device /'l is positioned in the circumferential direction with respect to the upper lattice plate /U, becomes non-rotatable, and is guided so that it can only move straight in the axial direction of the guide tube is. As the descent continues further, the corner flange of the guide tube/S and the upper lattice plate/
2, and the entire guide device/da is suspended from the upper grate board saw. In this state, as shown in FIG. 6, the lower part of the guide tube IS has already passed through the core support plate.

Next, the inspection device t is suspended from the operating shoulder floor. The skirt portion /6 captures the distal end portion 2'l of the descending inspection device IK as shown in Fig. S so as not to collide with the fuel assembly 9, and guides it into the guide pipe /S. The shape of the skirt part 6 is designed to prevent interference with surrounding fuel assemblies when the guide device 8i is suspended from the upper grid 8i, and to easily catch inspection equipment from above. It has been selected so that it can be done. The inspection device g guided by the skirt part /6 is guided by the guide #Iλ shown in FIG.
Guided automatically by the function of the widening part 2Ja of 3 @23
is fitted with the guide rail/of the guide tube/S. Due to this fitting, the inspection device is positioned in the circumferential direction with respect to the guide tube /3, and is guided so that it cannot rotate and can only move straight in the axial direction of the guide tube 15. In this way, as shown in FIG. 6, the inspection device g guided in the guide tube /, r quickly descends, and the tip end of the inspection device comes into contact with the O-shaped housing /3, as shown in FIG.

After that, when the inspection device g is further lowered, No. 51.7
As shown in the figure, the tip 27 is housed in the inspection device main body 22, and the lower end of the main body 2 catches the 0FID/Using/3. In this way, the inspection device is fixed to the ORD housing/3. At this fixed point in time, inspection device j is
It separates from the guide tube IS, the fitting between the guide groove J and the guide rail/7 is also released, and the inspection device g becomes rotatable. This inspection device g is controlled by a computer installed on the operation floor in such a way that it can be rotated during inspection and returns to the position where it was initially fixed to the 0FID housing at the end of one inspection. If the inspection device g is lifted as it is, the guide groove 23 of the inspection device g will definitely fit into the guide rail/knife of the guide tube /1 due to the upper widened portion λ3b, and the inspection device g will be promptly recovered on the operating floor.

Note that the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, in the embodiment, the inspection device ig includes a guide groove,
23 and the guide rails 17 were provided in the guide tube /j, but conversely, the inspection device may be used to press the guide rails so as to provide the guide grooves in the guide tube.

Cl) As is clear from the above description, according to the present invention, the guide tube is positioned in the circumferential direction with respect to the upper grid plate by the guided portion provided on the outer surface, and is inspected by the guided portion provided on the inner surface. Because the device is positioned and guided in the circumferential direction,
The inspection device is unaffected by the flow of cooling water and is lowered to a predetermined position at the bottom of the reactor with high viscosity. Furthermore, since the inspection device is guided by the skirt portion and passes through the guide tube, it can easily pass through the upper grid plate and the core support plate, and can quickly descend and ascend. As a result, accurate visual inspection can be carried out in a short time.
It is possible to reduce the amount of radiation exposure of workers and prevent the performance of inspection equipment from deteriorating.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view illustrating a conventional method for mounting a remote in-furnace inspection device on the bottom of the furnace, FIG. 2 is a perspective view showing an embodiment of the guide loading according to the present invention, and FIGS. Figure 1 is a side view and plan view showing the inspection device, Figure S is a sectional view showing the guide device suspended from the upper grid plate, and Figures 6 to 8 show the inspection device guided by the guide device. FIG. 3 is a cross-sectional view showing a state in which it is attached to the ORD housing, a state in which it is in close contact with the ORD housing, and a state in which it is fixed to the 3RD housing.
ri...Guide device, /S...Guide tube, /6...Skirt part, /7...Guide rail (guide part), 7g...
- Square flange hanging part, /q... Guide vibe (guided part) 1.23... Guide groove (inspection device guided part). Applicant's agent Kiyoshi Inomata (//) 1 Figure

Claims (1)

[Claims] 1. A guide tube having an internal space through which the in-furnace remote inspection device can pass, and a guide tube connected to the upper end of this guide tube and extending upward in order to guide the in-furnace remote inspection device to the guide tube. a skirt portion having a shape that opens outward according to the guide tube, and a guided portion on the outer surface of the guide tube that is guided by an upper lattice plate so that the guide tube can only move straight in the axial direction, and an upper lattice. Hanging portions that engage with the plates to suspend the guide tubes from the upper lattice plate are provided, and the inner surfaces of the guide tubes engage with guided portions formed on the outside of the in-furnace remote inspection device. A guide device for a remote in-furnace inspection device, characterized in that a guide portion is provided for movably guiding the in-furnace remote inspection device only in straight movement in the axial direction. E. The hanging part is a square flange protruding from the upper part of the guide tube, the guided part on the outer surface of the guide tube is a guide pipe hanging down from the square flange, and the guide part on the inner surface of the guide tube is a square flange protruding from the upper part of the guide tube. The in-core remote inspection device according to claim 1, characterized in that it is a guide rail extending in the direction. 3. The length of the guide tube is determined such that the guide tube passes through the core support plate while being suspended from the upper lattice plate. Or the in-core remote inspection device described in paragraph 2.