JP2984550B2 - Thermal sleeve drilling device for reactor vessel top nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling tool for a thermal sleeve of a reactor vessel head cap nozzle.

[0002]

2. Description of the Related Art FIG. 7 is a view focusing on one of a plurality of nozzles 2 attached to a reactor vessel lid 1. FIG. A plurality of nozzles 2 into which a thermal sleeve 3 is inserted are attached to the reactor vessel lid 1.
Is inserted so as to be movable in the longitudinal direction with respect to the nozzle 2 and to be rotatable concentrically. In a nuclear power plant, it is necessary to periodically inspect the inner surface of the nozzle 2 in order to confirm its reliability and maintain its safety. However, as shown in FIG. 7, the nozzle 2 has a double tube structure in which the thermal sleeve 3 is inserted. Even with an inspection method, for example, an ultrasonic inspection, it is difficult to perform an accurate inspection. Also, in the conventional eddy current inspection, liquid penetration inspection, and the like, since the gap between the nozzle 2 and the thermal sleeve 3 is very small, a sensor used for the inspection cannot be set.
It is difficult to confirm the soundness of a building.

[0003]

The inspection of the inner surface of the nozzle is difficult to perform with high accuracy for the reasons described above.
Since the components of the reactor vessel are radiation contaminants, there are problems such as exposure of workers engaged in the work and restrictions on radiation control, such as significant work time and poor workability. The rate was also affected. Accordingly, an object of the present invention is to provide an apparatus for drilling an inspection hole in a thermal sleeve so that the inner surface of the nozzle can be directly inspected in a nozzle having a double-tube structure and a thermal sleeve. .

[0004]

In order to achieve the above object, a drilling device according to the present invention checks a clamp mechanism for clamping a nozzle and a position of the drilling device with respect to the nozzle. A positioning visual mechanism, a tool elevating mechanism for raising and lowering the clamp mechanism, a cutting head elevating and rotating mechanism for moving the cutting head to a required position in the thermal sleeve, a cutting head driving mechanism for operating the cutting head, and suction And a cutting material collecting mechanism for holding and collecting cutting pieces of the thermal sleeve by the pads.

[0005]

The drilling device is moved to a position below the nozzle by remote control, and then the position of the drilling device is determined by a positioning visual mechanism, the clamp mechanism is raised by a tool elevating mechanism, and the drilling device is moved by the clamp mechanism. Fixed. Next, the cutting head is moved to a target position in the thermal sleeve by the action of the cutting head raising / lowering mechanism and the cutting head turning mechanism for moving the entire tool including the cutting head in the thermal sleeve. Then, the cutting head operated by the cutting head drive mechanism performs the drilling for inspection, and the cut member is recovered by the cutting material recovery mechanism, and the drilling in one nozzle and the thermal sleeve is completed. Further, the drilling device performs a movement opposite to the above-described operation to return to a movable state, moves to the next drilling operation, and repeats the above-described operation.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the accompanying drawings, in which the same reference numerals indicate the same or corresponding parts. In FIG. 1, a reactor vessel lid 1
Is mounted on a temporary mounting table 4 and a plurality of nozzles 2 and thermal sleeves 3 are provided. The cart 5 is placed on the floor below the nozzle 2 so as to be movable. A cylinder 6 is mounted above the cart 5, and a piston 7 and a piston 9 are connected by a joint 8. The piston 7 is attached to the cylinder 6 in a state where the piston 7 can be moved up and down.

In FIG. 2, a cylinder 10 to which a piston 9 is movably attached is fixed to a frame 11, and a clamping mechanism is connected to the nozzle 2 by the tool elevating mechanism.
To a suitable position at the lower end of the. The frame 11
It has two guides 12 arranged side by side and a rail 13
It is mounted and supported movably in the vertical direction. A positioning mechanism such as a rotary actuator 14 is provided in an upper portion of the frame 11, and an arm 15 provided with a television camera 16 and a mirror 17 is rotatably mounted on the rotary actuator 14. . Regarding the positioning visual mechanism composed of the TV camera 16, the nozzle 2
To the center of the TV camera 16 and mirror 17
To visually check the hole of the nozzle 2 and move the carriage 5 to a target position. Then, when the frame 11, that is, the tool is raised,
The TV camera 16 and the mirror 17 are rotated and moved to positions where they do not interfere with the nozzle 2.

Further, as shown in FIGS. 2 and 3, two clamp cylinders 18 mounted on the upper part of the frame 11 operate the clamp piston 19, and the clamp mechanism is axially mounted on the piston by pins 20. At the same time, a pair of clamps 22 connected by the pins 21 clamp the lower end 2b of the nozzle 2.

On the other hand, in FIG. 2, bearings 23 and 24 for supporting a feed screw 25 are provided below the frame 11, and the rotation of the feed screw 25 by the lift motor 26 raises and lowers a lift plate 28 having a nut portion. Can move up and down along the rail 27. Lifting motor 26
The entire cutting tool including the torch-shaped cutting head 36 can be moved up and down by the above-described cutting head elevating mechanism composed of the above. As for the cutting head turning mechanism, a rotation motor 37 is attached to the frame 11 to rotate a gear 38, and the gear 38 is rotatably supported by a bearing 39 fixed to the frame 11. Cylinder 40
The rotation is transmitted to a gear 41 integrated with the gear. Thereby, the cutting head 36 can be turned in the circumferential direction in the thermal sleeve 3.

On the other hand, an elevating motor 29 is attached to the elevating plate 28, and the elevating shaft 29
Drive 0. As best shown in FIG.
Is connected to a link 32 via a pin 31, which in turn is connected to a link 45 by a pin 33, which is pivotally supported at a pin 35 by a guide 34 and a pin 48. Is connected to one end of the link 49. The other end of the link 49 is supported by 50. The pin 50 is slidably supported by a pair of shafts 46 attached to the guide 34.

The rectangular frame-shaped cutting head 36 is supported by a torch case 47. When the elevating shaft 30 descends, it exhibits an advancing state as shown in FIG. 6, and when the elevating shaft 30 elevates, it assumes a housed state. . Next, returning to FIG.
Is integrally connected to a rotary sleeve 42. Above the rotating sleeve 42, a well-known clamp 43 is provided, and when the piston 44 of the cylinder 40 is lowered,
The inner surface of the thermal sleeve 3 and the rotary sleeve 42 are clamped and fixed.

As shown in FIG. 6, inside the torch case 47, a piston 51 fixed to the guide 34 and one upper and lower piston 51 and a cut piece of the thermal sleeve 3 having a cylinder corresponding to the piston 51 are collected. A section 53 and two suction pads 52 attached to the collecting section 53 are provided, and these constitute a cut material collecting mechanism. In these, the suction pad 52 is placed on the thermal sleeve 3 before processing.
After processing, the suction pad 52 that is adsorbing the cut pieces together with the collecting section 53 by the operation of the piston 51 is separated from the wall of the thermal sleeve 3 to collect the cut pieces.

At the time of processing by the cutting head 36, a spacer for preventing damage to the nozzle 2 (not shown) is inserted between the nozzle 2 and the thermal sleeve 3 in advance as necessary so as not to damage the inner surface of the nozzle 2. It is good to keep. Drilling in the thermal sleeve is performed by the above operation.

In the above embodiment, when cutting is performed by electric discharge machining, the cutting head 36 serves as an electrode, and
Reference numeral 3 denotes a water seal portion on the thermal sleeve 3 side, and further, the clamp 22 serves as a water seal portion between the nozzle 2 and the thermal sleeve 3.

[0015]

According to the present invention, in the inspection of the inner surface of the nozzle of the reactor vessel lid, which has been quite difficult in the past, the inner surface of the nozzle is directly inspected by making a hole in the thermal sleeve wall. And a highly accurate inspection result can be obtained. In addition to a mechanism for actual processing, a movable trolley, a positioning visual mechanism, a clamp mechanism, a cutting material recovery mechanism, etc. can be installed to enable remote inspection of multiple nozzles. It leads to improvement of problems such as exposure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a reactor vessel lid removed from a reactor vessel and an explanatory view of a device of the present invention installed on the same.

FIG. 2 is a partial sectional perspective view showing a main mechanism of the present invention.

FIG. 3 is a partial perspective view showing a clamp mechanism of the present invention.

FIG. 4 is an overall view of a working tool according to the present invention.

FIG. 5 is a partial sectional view showing a cutting head driving mechanism of the present invention.

FIG. 6 is a sectional view showing a state in which a processing tool is in a thermal sleeve.

FIG. 7 is a partially enlarged view showing a nozzle and a thermal sleeve attached to a reactor vessel lid.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reactor vessel lid, 2 ... Nozzle, 3 ... Thermal sleeve, 4 ... Temporary mounting table, 5 ... Dolly, 6 ... Cylinder, 7
... Piston, 11 ... Frame, 14 ... Rotary actuator, 16 ... TV camera, 18 ... Clamp cylinder, 19 ... Clamp piston, 22 ... Clamp fitting, 25 ... Feed screw, 26 ... Elevating motor, 28 ...
Elevating plate, 29 ... Elevating motor, 30 ... Elevating shaft, 36
... cutting head (torch-shaped cutting head), 37 ... rotating motor, 38 ... gear, 43 ... clamp, 52 ... suction pad, 53 ... collection part.

Claims (1)

(57) [Claims] 1. A drilling device for drilling a hole in a thermal sleeve when inspecting an inner surface of a nozzle attached to a reactor vessel upper lid and having a thermal sleeve inserted therein, wherein the nozzle is clamped. Clamping mechanism, a positioning visual mechanism for confirming and positioning the position of the drilling device with respect to the nozzle, a tool elevating mechanism for raising and lowering the clamp mechanism, and a cutting head at a required position in the thermal sleeve. Head lift and swivel mechanism for moving the cutting head, a cutting head drive mechanism for operating the cutting head, and a cutting material collecting mechanism for holding and collecting cutting pieces of the thermal sleeve by suction pads Thermal sleeve drilling equipment in.