KR200165200Y1 - Ultrasonic tester for the nuclear power plant steam generator sleeved-tubing - Google Patents

Abstract

The present invention is designed to prevent the loss of plugging caused by the occurrence of fittings (Pitting, SCC, etc.) at the top of the tube sheet of the steam generator tube due to the aging of nuclear power plants. The present invention relates to an ultrasonic inspection apparatus for nuclear steam generator sleeve-tube inspection developed for monitoring the welding state of the upper bore weld and preventing leakage of nuclear power plant first order due to defects occurring during operation.

Description

Ultrasonic Tester for Nuclear Steam Generator Sleeve Tube Inspection {Ultrasonic Tester for the Nuclear Power Plant Steam Generator Sleeved-tubing}

The present invention is designed to prevent the loss of plugging caused by the occurrence of fittings (Pitting, SCC, etc.) at the top of the tube sheet of the steam generator tube due to the aging of nuclear power plants. The present invention relates to an ultrasonic inspection apparatus for nuclear steam generator sleeve-tube inspection developed for monitoring the welding state of the upper bore weld and preventing leakage of nuclear power plant first order due to defects occurring during operation.

In the conventional ultrasonic wave inspection device, an ultrasonic reflection mirror is installed in front of the transducer during ultrasonic longitudinal wave or transverse wave inspection to scan the ultrasonic wave emitted from the ultrasonic probe at a desired angle. However, in order to scan the ultrasonic wave emitted from the ultrasonic probe to the test object at the desired angle, the transducer and the reflector should be manufactured and installed so that the ultrasonic wave accurately reaches the center of the reflector, and due to the ultrasonic signal scattered at various angles inside the reflector, And evaluation difficulties, and it was difficult to accurately install the reflector in front of the transducer. In addition, a small motor capable of rotating the reflector in a small space and a number of cog wheels have to be arranged and installed in order to inspect the sleeve circumferential 360 degree welding part, which complicates the device, resulting in economic loss and inspection time due to frequent failures. In addition, due to frequent repairs and repairs, there are various problems such as an increase in radiation exposure time due to an increase in radiation exposure time.

The present invention has been made in consideration of the above problems, and its purpose is to insert the ultra-sonic probe directly into the lusite wedge and inspect the upper end of the sleeve tube by the stepwise scanning method for the extension of the lifetime of the nuclear power plant steam generator tube. The present invention provides an ultrasonic inspection apparatus for inspecting nuclear steam generator sleeve tubes that can more economically and easily inspect the integrity (good bonding state) of the nuclear power plant.

The present invention, in order to achieve the above object, in the inspection device for inspecting the inner sleeve tube welded portion of the steam generator heat pipe, the inspection device is an ultra-sonic ultrasonic probe is inserted into the cylindrical lusite wedge and installed, One side is connected and installed on the upper / lower support which is installed on the upper / lower side of the site wedge to support the lusite wedge, and is operated integrally with the lusite wedge, and the lower side of the rouge wedge inserted into the lower support. High-strength wire connected to the stepping motor installed in the rotating part to rotate the rouge wedge inserted and installed by the ultrasonic probe, and the lower support and the one end is connected to and installed at the other end of the connecting rod bearing bearing, and the through hole is formed inside A pipe, a push puller for vertically moving the flex pipe, and the lower flex sensor It is connected to the flex pipe so as to be located at the bottom of the turing member, and the water supply and drain holes are provided to supply water between the sleeve tube and the rouge wedge, and the rubber packing is installed on the flex pipe so as to be located below the supply and drain holes. The present invention provides an ultrasonic inspection apparatus for inspecting a nuclear steam generator sleeve tube that can inspect an upper end weld portion of a sleeve tube.

1 is a sleeve form of ABB company installed in the domestic nuclear power plant

Figure 2 is a detailed view of the sleeve top welded in the defect-prone areas

3 is a schematic view of the sleeve welding unit ultrasonic inspection device

4 is a schematic diagram of an ultrasonic scanning device

5 is a screw scanning method

6 is a stepped scanning method

7 is an internal configuration of the ultrasonic welding device for the sleeve weld

* Explanation of symbols for main parts of the drawings

(10): steam generator heating tube (11): sleeve tube

(12): ultrasonic transducer 13: distilled water

14: air gap 15: upper flex centering member

(15`): Lower flex centering member (16): Rubber packing

(17) cylindrical cylindrical sight wedge (18): supply and drain

(19): ultrasonic beam stroke scanned in the weld

(20): flex pipe (20`): through hole

(21): Push-puller (22): Spring steel for tachometer

23: high tension wire 24: upper support

(24`): lower support (24 ″): connecting rod

26: electric wire

(A): Leakage area due to welding failure

(B): top bore welding (F): flush welding

(T): tube (W): welded portion

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a detailed view of the sleeve form of the ABB company installed in the domestic nuclear power plant, 2 is a detailed view of the upper sleeve welding portion of the defect-prone areas, 3 is a schematic diagram of the ultrasonic welding device of the sleeve weld, 4 is a schematic diagram of the automatic ultrasonic scanning device, 7 is a diagram showing the internal structure of the ultrasonic welding device of the sleeve welded portion, the nuclear power plant steam generator heat pipe 10 is a defect occurs in the tube when the number of years of operation increases, resulting in a leak occurs because of the overlaid tube or sleeve tube ( Insert 11) and double the thickness of the pipe while welding the upper bore with the first degree on the curved part.

The present invention is to inspect the upper bore welding site, insert and install the ultra-sonic ultrasonic transducer 12 inside the cylindrical roux wedge 17, the upper / lower support (upper / lower support) in the upper / lower portion of the rouge wedge (17) 24, 24 'and the lower support 24' and a stepping motor (not shown) are connected by the high tension wire 23 to rotate the rouge wedge 17 in which the ultrasonic transducer 12 is installed. It is. In addition, the transducer 12 is moved up and down in the sleeve tube 11 by connecting one side of the lower support 24 ′ to the flex pipe 20 vertically moved by the push puller 21. The water flows through the air supply and drain holes 18 between the sleeve tube 11 and the rouge wedge 17 so that the ultrasonic transducer beam stroke 19 is well transmitted, and at the same time, water leaks by the rubber packing 16. Is blocked.

The ultra-sonic probe 12 is inserted and installed directly inside the cylindrical roux wedge 17, and the rouge wedge 17 is supported by upper and lower support members 24 and 24 'installed at the top and bottom.

The upper and lower supports 24 and 24` are respectively installed on the upper and lower portions of the rouge wedge 17, and support the rouge wedge 17 and operate integrally with the rouge wedge 17. Upper and lower flex centering members 15 and 15 'are respectively connected to an upper portion of the support 24 and a lower portion of the lower support 24'.

The high tension wire 23 rotates and operates the rouxite wedge 17 and the upper and lower supports 24 and 24 ', and the lower side of the rouge wedge 17 is inserted into the lower support 24'. The other side is connected to a stepping motor (not shown). That is, since the rouge wedge 17 is inserted into the lower support 24 ′, the high tension wire 23 connected to and installed under the rouge wedge 17 inserted and installed into the lower support 24 ′. When the rouxite wedge 17 is rotated, the upper and lower supports 24 and 24 'also rotate integrally with the rougeite wedge 17.

The upper and lower flex centering members 15 and 15` are installed to be positioned at the upper and lower portions of the supports 24 and 24`, respectively, and one end thereof is connected and installed to the supports 24 and 24` by a bearing. The connecting rods 24 ″ are coupled to each other by bearings while maintaining a constant distance from the upper and lower supports 24 and 24 '.

The flex pipe 20 transmits the actuation force of the push puller 21 to the lusite wedge 17 and the upper / lower supports 24 and 24 'provided with the ultrasonic transducer 12, and the lower support 24'. And one end is connected to and installed at the other end of the connecting rod 24 ″ connected and installed by a bearing, and is connected to the wire 26 and the supply / drainer 18 connected to the ultrasonic probe 12 therein. A through hole 20 'through which a drain pipe (not shown) and the shielded high tension wire 23 passes is formed, and has a bend shape and a tubular material having excellent frictional force.

The water supply / drainage port 18 is introduced into the flex pipe 20 so as to be positioned under the lower flex centering member 15 ′ by introducing water, which is a contact medium, between the sleeve tube 11 and the lusite wedge 17. .

The rubber packing 16 prevents leakage of water introduced between the sleeve tube 11 and the lusite wedge 17 through the water supply and drain holes 18, and is positioned so that the rubber packing 16 is located below the water supply and drain holes 18. It is installed in the pipe 20.

That is, the present invention is the flex pipe 20 is pushed by the push puller 21, the flex pipe 20 is moved up / down by the rotational movement of the push puller 21, ultrasonic wave by the flex pipe 20 Lusight wedges 17 with installed transducers 12 and upper and lower supports 24, 24 ′ vertically move within the sleeve tube 11 and have high tension wires 23 connected to a stepping motor (not shown). By the cylindrical rosite wedge 17 is a rotary motion. At this time, the rouxite wedge 17 and the sleeve tube 11 are not in contact with each other, and the upper and lower supports 24 and 24 'into which the upper and lower portions of the rouge wedge 17 are inserted and the upper and lower flex centering members ( 15,15`) are bearing-coupled, so that the rotational force is transmitted through the high tension wire 23 even with a small force.

In addition, water, which is a contact medium, is supplied to the upper portion of the rubber packing 16, that is, between the rouxite wedge 17 and the sleeve tube 11 through the supply / drainage port 18 so that the ultrasonic beam stroke 19 is well transmitted. .

As such, the present invention vertically moves the rouxite wedge 17 in which the ultrasonic transducer 12 is installed by the push puller 21 and the flex pipe 20 to a high tension wire 23 connected to a stepping motor (not shown). As a result, the rouge wedge 17 is rotated so that the integrity (good bonding state) of the upper end welded portion of the sleeve tube 11 can be inspected by a step scan method as shown in FIG.

In addition, the core of the present invention can be inspected as close as possible to the test tube, the sleeve tube by inserting the micro detachable micro probe directly into the inside of the cylindrical lusite (pulprex) wedge as the third degree inside the small tube inside the 2 cm diameter Therefore, it is possible to drastically improve the pseudo defect signal and the ultrasonic signal-to-noise ratio caused by the ultrasonic scattering, which is a problem of the conventional method.

In addition, an essential element in the bend tube is that the smaller the length of the transducer, which is composed of the length of the member and the cylindrical lusite, the more advantageous it is. Bend tube inspection is possible. In particular, by processing only the body of lusite, the beam angle can be easily adjusted as well as the angle of the ultrasonic wave that enters the inside of the specimen. Can be.

In addition, in the conventional Helical Scan method (see FIG. 5), a complicated structure using multiple reduction gears inside a cylindrical probe bundle of 2 cm or less in diameter for rotating the reflector is simplified and the weight of the device is reduced to 1 It is possible to reduce the weight to / 10, and to use the step scan method that can increase the efficiency and resolution of the inspection, thereby improving the reliability and reproducibility of the inspection.

As such, the present invention is an ultra-sonic probe capable of remote automatic inspection from small tubes to large tubes.In particular, the soundness evaluation of steam generator heat pipes and sleeve pipes, which are high-radiation areas, the automation of inspections in high-radiation areas, and poor welding conditions, There are many effects, such as preventing the plant from shutting down by preventing the first leakage of nuclear power plants.

Claims (1)

An inspection apparatus for inspecting an inner sleeve tube welded portion of a steam generator heat pipe; The inspection apparatus includes a micro ultrasonic probe 12 inserted into and installed in the cylindrical lusite wedge 17; Upper and lower supports (24, 24 ') installed at the upper and lower portions of the rouge wedge (17) to support the rouge wedge and integrally operate with the rouge wedge; High tension wire for one side connected to the lower part of the rouge wedge inserted into the lower support 24 ′ and connected to a stepping motor installed at the other side to rotate the rouge wedge in which the ultrasonic transducer 12 is inserted and installed ( 23); Upper / lower flex centering members 15, which maintain a predetermined distance from the upper / lower supports 24 and 24 'to the connecting rods 24 ″ having one end coupled to the upper and lower supports 24 and 24`, and 15`); A flex pipe (20) connected to and installed at the other end of the connecting rod (24 ") to which the lower support (24 ') and one end thereof are coupled, and having a through hole (20') formed therein; A push puller 21 for vertically moving the flex pipe 20; A supply / drainage port 18 connected to the flex pipe 20 so as to be positioned at the lower end of the lower flex centering member 15 'to supply water between the sleeve tube 11 and the rouge wedge 17; A nuclear power plant steam generator sleeve including a rubber packing 16 installed on the flex pipe 20 to be positioned below the water supply and drain holes 18 to inspect the upper end weld portion of the sleeve tube by a stair scanning method. Ultrasonic tester for tube inspection.