JPS62233794A - Inspection device in pressure vessel for nuclear reactor - 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 [Field of Application of the Invention] The present invention relates to a reactor pressure vessel internal inspection device, and particularly relates to a reactor pressure vessel internal inspection device of a boiling water reactor. This relates to inspection equipment.

[Background of the invention]

A conventional nuclear reactor pressure vessel internal inspection device will be explained with reference to FIGS. 1 to 3. TV camera 2 attached to drive device 5
6 is normally suspended from a grapple 4 at the tip of a fuel gripping device of a fuel exchange machine 2 used for fuel exchange. The horizontal and vertical position control of the television camera 6 is performed by the control device of the fuel exchange machine 2.
The attitude and image of the reactor pressure vessel are controlled by the reactor pressure vessel internal inspection device control device 3).
A visual inspection of the area will be performed. The detailed view of part A in Figure 1 is shown in Figure 2.
As shown in the figure. The TV camera 6 looks directly.

- It has a structure that allows it to be rotated, and the photographing direction can be changed from a vertical position to a horizontal position using the elbow mechanism 7, and it is also capable of rotating from 0 to 3606 degrees. However, due to the rounded shape of the mechanism, it is difficult to insert a thick position into the 3 meeting area between the jet pump 8 and the jet pump 8, which is positioned below the shroud 7 flange 15 as shown in Figure 3. Therefore, a satisfactory test could not be performed.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reactor pressure vessel interior inspection device that can inspect the vicinity of a jet pump located below a shroud flange.

[Summary of the invention]

The present invention is characterized by having an extra-furnace system installed outside the pressure vessel and directly operated by an operator, and an in-furnace system installed inside the pressure vessel and operated remotely by an operator, wherein the in-furnace system is , a base station that serves as an operating reference for the inspection device, an insertion mechanism for approaching the vicinity of the jet pump from this base station, and a terminal station that is guided by this insertion mechanism and serves as a reference at the approach point; The optical head for visual inspection is equipped with a rotating mechanism or tortoise for guiding and positioning the optical head to the inspection point of the riser brace.

[Embodiments of the invention]

The present invention focuses on the fact that conventionally it was difficult to inspect the vicinity of the jet pump 8 located below the shroud 7 flange 15 due to its shape 9 mechanism, and developed an in-reactor inspection device inserted into the reactor pressure vessel 1. The structure is such that it can be inserted near the jet pump 8. That is, the present invention provides a base station that serves as an operating reference for the inspection device, an insertion mechanism for approaching the vicinity of the jet pump 8 from this base station, and a terminal that is suspended from this insertion mechanism and serves as a reference at the approach point. - Consists of a station and a turning mechanism 20 that guides and positions the visual inspection optical head to the inspection location of the riser brace. The insertion procedure involves first inserting and installing the base station with each mechanism built-in and installed, and then inserting each mechanism in stages.

The operator outside the reactor confirms the position using the control device and television camera, and inspects the structures inside the reactor pressure vessel and the equipment in the narrow spaces in stages using the three-step approach procedure described above. I do.

A specific embodiment of the present invention will be described below with reference to FIGS. 3 to 10.

Figure 3 shows that in the conventional reactor pressure vessel internal inspection equipment,
FIG. 2 is a schematic diagram of the vicinity of the jet pump 8, which was difficult to inspect.

It is necessary to inspect the area around the welded part 11 between the riser brace 10 that supports the jet pump 8 with respect to the pressure vessel 1 and the pressure vessel 1. However, there is a water supply sparger 12 above the upper ring 15. Since the core spray piping 13 is located, it is necessary to avoid both of them, and to have a structure that allows the inspection device to be inserted around the riser brace welded portion 11, which is the inspection point. A fourth device that can handle this
Let's explain from the diagram.

FIG. 4 shows an overall view of the reactor pressure vessel internal inspection device according to the present invention. The reactor pressure vessel internal inspection equipment system consists of an external system installed outside the pressure vessel 1 and operated directly by the operator, and an in-core system installed inside the pressure vessel 1 and operated remotely by the operator. It consists of

The in-core system also includes an insertion mechanism 1B that approaches the vicinity of the jet pump 8 from a base station 17 that serves as an operating reference for the inspection device, and a terminal stay 7 that is suspended from the insertion mechanism 18 and serves as a reference at the approach point. 4D-included mechanism 20 that guides and positions the Yon 19 and the optical head 21 for visual inspection to the inspection location of the riser place 10.
Consisted of.

This will be explained in detail below. The operation (approach) procedure of the device is roughly divided into three stages. That is, in the first step, the rotation mechanism 20. The base station 17, which is equipped with the terminal station 19, etc., is lifted up by the building crane 16, etc., and placed inside the pressure vessel l, and the water supply sparger 1 is placed inside the pressure vessel l.
2. Avoiding the core spray piping 13, it is lowered to just above the 7-Roud head. Next, it is brought close to the inner wall of the pressure vessel 1 at that height and further lowered along the inner wall, with the inner wall being the reference in the radial direction of the pressure vessel 1, and downward onto the base station 17 in the circumferential direction. Using the installed surveillance camera 22 (see Fig. 5), install the above-mentioned furnace system on the 7-round flange (upper ring) 15 using the 180° bend of the jet pump 8 as a reference. . Thereafter, as shown in FIG.
Positioning is performed in the circumferential direction and the radial direction by a positioning mechanism 24 installed at. Figure 5 shows base station 1
7 is shown, and the base station 17 is shown installed on the shroud flange (upper ring) 15.

Next, in the second step, the base station 17 is used as a base, and the terminal station 19 and m
The insertion mechanism 1B suspending the insertion mechanism 20 is operated to lower it through the narrow gap between the pressure vessel 1 and the shroud 14 to the vicinity of the riser brace IO. optical head 2
1 at a predetermined inspection distance with respect to the inspection position of the riser brace 10, the operator moves the optical head 21
Align the insertion direction while monitoring the Next, as shown in FIG. 6b, the clamping mechanism 26 of the terminal station 19 is actuated to fix the terminal station 19t'' in the space between the pressure vessel 1 and the shroud 140.

FIG. 6a shows the insertion mechanism 18 in a stored state, and FIG. 6b shows the insertion mechanism 18 in an inserted state.

In the third step, starting from the terminal station 19, the turning mechanism 20 is moved in accordance with a predetermined sequence.
The optical head 21 attached to the tip is automatically operated.
is guided to the inspection position of the riser brace 10, and the operator inspects this inspection image through a television monitor outside the furnace.

As described above, the reactor pressure vessel internal inspection device according to the present invention is characterized by having a distributed function structure that approaches in three stages.

Next, major/? ! The r mechanism will be explained in detail.

FIG. 5 shows a structural diagram of the base station 17, of which the positioning mechanism 2 is mounted with each mechanism and is positioned with respect to the lug 9 of the 7-eraud flange 15 in the 9 state.
4 will be explained. This is configured so that the positioning poom 25t is rotated by a screw drive and the lug 9t is inserted from both sides. The position of the base station 17 in the radial and circumferential directions with respect to the pressure vessel 1 is corrected using the lug 9 as a reference.

Figures vJ6a and 6b show the insertion mechanism 18 in the retracted and pushed-in states, respectively. The insertion mechanism 18 is roughly divided into a first insertion mechanism 18a and a second insertion mechanism 18b.

The first insertion mechanism 188 suspends the wrap-around mechanism 20 and the terminal station 19 while avoiding the core spray piping 13 and the water supply sparger 12.
It is necessary to insert the sb diagonally at first (see Figure 6a) and then install it vertically at the end of the insertion stroke (see Figure JGb). The second insertion mechanism 18b inserts the rotation mechanism 20 and the terminal stay 19 into the jet bong 7' 8
It is inserted into the vicinity (see Figure 6b).

7 and 8 show the structure of the latch mechanism.

The latch mechanism is activated by the operation of the insertion mechanism 18.
Station 19 is excavated and there is a terminal stage to prevent it from hitting the furnace wall of the pressure vessel WBI. This organization is
Using a toggle joint mechanism, the insertion mechanism 18 is operated by a direct drive cam 27 attached to the main body of the base station 17.
It has a structure that automatically engages and releases when it is inserted and pulled out. This latch mechanism allows the terminal station 19 to be safely lowered and inserted into the insertion mechanism 18 close to the inspection position.

FIG. 9 shows the structure of the clamp mechanism 31. A clamp mechanism 11 is for fixing the main body of the terminal station 19 between the pressure vessel 1 and the 7-layer 14. This clamp mechanism 31 includes a clamp opening/closing mechanism 26 that horizontally pulls up the folded clamp arm;
Slightly extend the outer and inner parts of the clamp arm tips and attach them to terminal station 19 (JJ
The main clamp mechanism 30s, z m rJF, which tensions and fixes the inner pre-flang mechanism 29, the outer pre-clamp mechanism 2B, and the terminal station 19 between the pressure vessel l and the shroud 14.
-Y +>A straight ^1 FIG. 10 shows the configuration of each drive shaft of the rotation mechanism 20. This machine is a mechanism that has a folding Cff1 type 4 link (33~: (6)) and joints (39~41) that can be approached while going around the jet pump 8. An auxiliary rotating shaft 32 for reversing the link posture to approach the jet pump 8 gap on the pressure vessel 1 side from the jet pump 8 gap or the adjacent jet pump 8 on the opposite side, and a rotation mechanism 20
Rotation of the axis 37 and optical head 21 for visual inspection to change the overall position.

It is also equipped with swing axes 42 and 43.

〔Effect of the invention〕

According to the present invention, it is possible to efficiently inspect narrow spaces such as the internal structure of a reactor pressure vessel, particularly around a jet pump, and detect transverse strain defects.

[Brief explanation of drawings]

Figure iA1 is an overall view of a conventional reactor pressure vessel internal inspection system, Figure 2 is a detailed view of section A in Figure 1, Figure 3 is a schematic view of the vicinity of the jet pump, and 6! Figure S4 is an overall view of the reactor pressure vessel internal inspection device according to the present invention, Figure 5 is a front view of the Habase station, Figure 6a is a front view showing the insertion mechanism in the retracted state, and Figure 6b is the inserted state of the insertion mechanism. Figures 7 and 8 are front views showing the structure of the latch mechanism, Figure 9 is a front view showing the structure of the clamp mechanism, and Figure 10 shows the configuration of each drive shaft of the rotation mechanism. FIG. l... Reactor pressure vessel, 2... Fuel exchange machine, 12.
... Water supply sparger, 13 ... Core spray distribution [,1
4... 7 euros, 16... construction fflli L/-7%
17... Heath station, 18... Insertion mechanism, 19... Terminal station, 25...
・Positioning arm, 26... Clamp opening/closing mechanism, 27
...Automatic cam, 28...Outer pre-clamp mechanism, 29
...Inner pre-clamp mechanism, 30... Main clamp mechanism, 31... Clamp mechanism. () Rod figure 4

Claims (1)

[Claims] 1. It has an extra-furnace system that is installed outside the pressure vessel and is directly operated by an operator, and an in-furnace system that is installed inside the pressure vessel and is remotely operated by an operator, and the in-furnace system is inspected. A base station that serves as a reference for the operation of the device, an insertion mechanism for approaching the vicinity of the jet pump from this base station, a terminal station that is suspended from this insertion mechanism and serves as a reference at the approach point, and a terminal station for visual inspection. A nuclear reactor pressure vessel interior inspection device comprising: a rotation mechanism for guiding and positioning an optical head to an inspection location on a riser brace.