KR20140064425A - The automatic ultrasonic inspection apparatus and method for stud of nuclear reactor - Google Patents

Abstract

The present invention relates to a method and a device for inspecting whether there is damage in a stud to fasten a nuclear reactor vessel and a nuclear reactor upper head which are key facilities in a nuclear power plant. More specifically, the present invention relates to the technologies of: inserting an ultrasonic probe into a center hole of a stud; automatically moving the ultrasonic probe to acquire an ultrasonic signal; and detecting a defect. Considering that the nuclear reactor is placed in a state of the high temperature and the high voltage as the nuclear reactor cooling material is heated by the high energy generated by the reaction nuclear fuels loaded in the nuclear reactor and the nuclear fission, since the high tensile stress is also applied to the stud to fasten the nuclear reactor vessel and the nuclear reactor upper head, the nuclear power plant manually performs an inspection by applying an ultrasonic inspection method during the inspection while operating the nuclear power plant. When the inspection is manually performed, an inspector analyzes an ultrasonic signal waveform of a detector at site to determine whether there is a defect, and the inspection result is completely relied on the judgment of the inspector. Furthermore, there is no means to record the inspection result and, therefore, the reliability of the inspection result can be reduced, and the objective inspection cannot be performed. To solve the problems while escaping from the existing manual inspection method, the present invention provides the method and the device capable of: automatically inspecting whether there is a defect in the stud by applying a device to insert an ultrasonic probe into a center hole of a stud and move the ultrasonic probe in an axis direction while rotating the ultrasonic probe in a rotation direction; storing the inspection result in a digital format to allow a re-evaluation and a follow-up inspection; and three-dimensionally displaying the stored inspection result to accurately evaluate the signals, thereby improving the inspection reliability.

Description

Technical Field [0001] The present invention relates to an automatic ultrasound inspection apparatus and method,

[0001] The present invention relates to an apparatus and method for testing a nuclear reactor automatic reactor ultrasound (nuclear reactor) for inspecting cracks using ultrasonic waves among various methods for examining whether or not a nuclear reactor reactor core and a stud for fastening a reactor head are damaged.

Nuclear power generation uses nuclear fuel in the reactor to heat the primary cooling water using the energy generated during nuclear fusion, transfers energy from the steam generator to the secondary cooling water by using the heated energy, The turbine converts it into rotational energy to produce electricity from the generator.

Since the nuclear fuel is charged into the reactor and the high energy generated by the fission reaction is heated to a high temperature and high pressure by heating the reactor coolant, the stud 120, which fastens the reactor vessel and the reactor head 110, Stress may be applied and cracks may be generated in the thread 210 of the stud 120 and lead to breakage.

Therefore, in order to check the soundness of the stud 120, the ultrasonic inspection method is applied periodically during the inspection during operation. The present ultrasonic inspection technique is an ultrasonic inspection technique in which an examiner receives an ultrasonic wave from the upper part of the stud 120 by holding the ultrasonic probe 230 or connects the ultrasonic probe 230 to the ultrasonic probe 240, And a method of inserting the probe into the test tube is widely applied.

Existing inspection methods will be described with reference to FIGS. 2 and 3. FIG.

The conventional manual inspection technique mainly detects the presence or absence of defects 290 generated in the thread 210 of the stud 120 by using a cylindrical ultrasonic probe having a vertical and a rectangular ultrasonic sensor arranged in the center hole 220 230 is fastened to the ultrasonic transducer rod 240 and the ultrasonic transducer rod 240 is inserted and inserted into the center hole 220. The ultrasonic transducer rod 240 is then rotated 360 degrees in the circumferential direction, In the order of inspection. The ultrasonic wave generated by the ultrasonic probe 230 traveling vertically, forward, or backward is propagated to the ultrasonic probe 230 after being reflected by the thread 210 as shown in FIG. Ultrasonic signals reflected from a healthy region exhibit complex waveforms with multiple peaks reflecting ultrasound waves from uniformly arranged threads as shown in FIG.

When a crack 290 occurs in the thread, ultrasonic energy 250 is reflected in the crack 290, and ultrasonic waves can not propagate to the back of the crack, so that no signal appears from the thread after the crack. This is called a shadow effect. In the stud inspection, a signal 260 reflected from a defect and a shadow effect 270 determine whether a defect occurs.

However, if the examiner manually holds the ultrasonic probe bar 240 and inserts the ultrasonic probe 230 into the bore 220 and rotates while moving vertically, the vertical moving distance can not be maintained constant, And 360 degrees in the circumferential direction can not be completely rotated. Therefore, there is a possibility that the ability to detect defects in the stud may be deteriorated.

In addition, in the conventional manual inspection, the operator performs a complicated operation of grasping the ultrasonic probe rod while rotating and inserting the ultrasonic probe and analyzing the signal of the ultrasonic probe. Therefore, the operator can not concentrate on the signal evaluation work, There is a problem that objective test results can not be obtained because the test results can not be recorded or stored.

As a result, in the passive test, the examiner must rotate the ultrasonic probe in the vertical direction simultaneously. Therefore, it is difficult to 100% test the area to be inspected and the signal can not be stored. In addition, the reliability and accuracy of the test There is a problem that it can not be secured.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an apparatus for inspecting a nuclear reactor nuclear reactor reactor and a stud for fastening a reactor vessel, wherein an ultrasonic probe is inserted into a bore hole of a stud, The entire inspection area of the stud hole can be accurately and quickly inspected by the method of vertically moving and rotating again.

Another object to be solved by the present invention is to provide a digital inspection system capable of 100% inspection of an inspection area which can be missed by a conventional inspection by a tester, It is possible to express the test result in two dimensions by combining the direction position with the ultrasonic signal and also to evaluate the test signal evaluation by converting the position of the radius echo (r) of the signal using the circumferential angle? It is easy to detect the defect position, thereby remarkably increasing the inspection accuracy.

Another problem to be solved by the present invention is to replace the entire amount of defects when the studs are detected, but it is possible to accurately measure the length and height of the defects, so that the replacement period can be estimated by evaluating the usable period by the fracture mechanics method Therefore, it is also economical to reduce losses.

The present invention solves the problem of the present invention by inserting an ultrasonic probe into the center hole of a stud, measuring the presence or absence of a defect while the ultrasonic probe rotates 360 degrees in the center hole, and moving the vertically upward and downward inside the center hole of the stud, In order to control the operation of the ultrasonic transducer remotely, it is necessary to measure the moving distance in the axial direction and the circumferential direction to the motor that vertically feeds the ultrasonic probe and the motor which controls the rotation, The ultrasonic inspection result is two-dimensionally displayed in the axial direction and the circumferential direction so that the inspectors can easily determine the presence or absence of the defect and the size of the defect without removing the entire length of the center inspection area of the stud Reactor stud automatic ultrasonic inspection that can dramatically increase inspection speed and inspection accuracy To provide the value and methods.

A further object of the present invention is to obtain position data of each position using a reactor vertical encoder and a rotary direction encoder and to map the reflected ultrasonic signals measured at each position to each other to store the defect position of the stud accurately The present invention provides an apparatus and method for automatic reactor ultrasonic inspection.

A further object of the present invention is to provide a method and apparatus for measuring data obtained at respective positions in a vertical direction and a rotational direction by using a stud circumferential direction (?) As a horizontal axis and a vertical direction of a stud as a vertical axis (y), and is displayed on a monitor. The present invention also provides an apparatus and method for automatically testing a reactor-stator automatic ultrasonic inspection apparatus.

As described above, the present invention is an apparatus for inspecting studs for fastening a reactor head and a reactor vessel of a nuclear power plant, in which an ultrasonic probe is inserted into a bore hole of a stud, rotated 360 degrees in the circumferential direction, The entire inspection region of the stud hole can be inspected accurately and quickly.

Another effect of the present invention is that not only can 100% inspection area which can be missed in the manual inspection by the conventional inspectors, but also the digital results of the inspection are stored and the vertical and circumferential positions (R) position of the signal by using the circumferential angle (θ) and the ultrasonic propagation distance, it is possible to easily and precisely measure the test signal, Position detection is easy.

Yet another effect of the present invention is that if all the defects are detected in the studs, the entire length of the studs can be measured, but the length and height of the defects can be accurately measured. Thus, the period of use can be estimated by the fracture mechanics method, There are many advantages in terms of people.

1 is a view showing a reactor structure and a stud position.
Fig. 2 shows the shape and manual inspection method of the reactor stud.
3 is a diagram showing the shape of an ultrasonic signal according to presence or absence of a defect in a stud.
Fig. 4 shows a configuration of an automatic testing apparatus for a stud.
Fig. 5 shows the operation principle of the automatic testing apparatus of the stud.
Fig. 6 shows an embodiment of the inspection using the present invention.
7 is a configuration diagram of an actual inspection system using the present invention.
FIG. 8 is a view showing a test result signal when the inspection method of the present invention is used.

Hereinafter, the present invention will be described in detail.

The present invention relates to a method for inspecting cracks by using ultrasonic waves and an inspection apparatus relating to the cracks to check whether the reactor vessel 100 as a core facility of a nuclear power plant and the stud 120 for fastening the reactor upper head 110 are damaged Is an ultrasonic inspection device.

More particularly, the apparatus and method for testing a reactor-stalled automatic ultrasound probe according to the present invention are characterized in that the reactor vessel 100, which is a core facility of a nuclear power plant, and the stud 120 for fastening the reactor head 110 are damaged. A rotating motor for rotating the probe, a vertical feed motor for vertically moving the ultrasonic probe vertically, and a vertical encoder and a rotating direction encoder for detecting the positions of the probes, And to inspect it accurately.

An apparatus and method for testing a reactor-mounted automatic ultrasonic probe according to the present invention will be described in detail with reference to the drawings.

Fig. 4 shows the configuration of the automatic inspection apparatus of the stud, and Fig. 5 shows an enlargement of Fig. 4 to show the fastening relationship of the respective configurations.

The present invention will be described with reference to Figs. 4 and 5. Fig. The present invention can be applied to an automatic ultrasonic inspection apparatus 300 for testing an ultrasonic probe transporter 310 connected to an ultrasonic probe 230 by using a vertical transfer motor 330 and a vertical transfer gear 430, The probe transducer 310 is configured to move vertically and vertically and the ultrasonic probe 230 can be rotated in the circumferential direction by using a rotary motor and a rotary gear 460.

A stud fastening part 360 having a female thread formed therein so as to be fastened to a thread formed on the stud is provided on the stud 120 to be tested and an ultrasonic probe 230 is provided on the stud, A vertical conveying motor 330 for conveying the ultrasonic transducer conveying belt 310 in the axial direction and a rotary motor 340 for rotating the ultrasonic transducer conveying belt 310 in the circumferential direction are provided.

A vertical encoder 335 and a rotary direction encoder 345 are fastened and mounted to the vertical conveying motor 330 and the rotary motor 340 so as to measure the conveying distance and the rotation angle, So that the distance and rotation angle of the ultrasonic probe can be accurately measured.

The driving concept will be described in detail with reference to FIG. When the rotary motor 340 is driven, the upper components including the rotary gear box 350 are rotated together with the rotary bearings 450 by the rotary gear 460 coupled with the body of the stud coupling part 360 .

The ultrasonic transducer transporting rod cylinder 410 having a " + "-shaped shape capable of freely sliding in the vertical direction is provided on the upper part of the inspection apparatus and configured to rotate in the circumferential direction while supporting the ultrasonic transducer transporting rod 310 Respectively.

The ultrasonic probe transporter cylinder 410 is fixed to the inside of the ultrasonic transducer transporter case 320. The ultrasonic transporter transporter case 320 is configured such that when the rotation motor 340 is rotated, And the probe feeder cylinder 410 also rotates together.

The ultrasonic probe transporter 310 inserted in the "+ " groove of the cylinder also rotates together with the ultrasonic probe 230 connected to the end of the transporter so as to rotate in the center hole 220 of the stud.

That is, when the rotation motor 340 rotates, the rotation gear 480 coupled to the stud coupling 360 rotates, and the rotation direction encoder gear 480 connected to the drive shaft of the rotation motor 340 And is configured to rotate the shaft of the ultrasonic probe bar 240 connected to the rotation direction encoder gear 480 so as to measure the rotation angle with the rotation direction encoder.

When the axial direction vertical feed motor 330 is operated, the vertical feed gear 430 vertically feeding the ultrasonic transducer connected to the motor is rotated, and the vertical feed gear 430 vertically feeding the ultrasonic transducer and the ultrasonic transducer feed The gears horizontally machined in the body of the drum 310 are mutually fastened in a rack and pinion structure to convert the rotary motion into a rectilinear motion so as to transfer the ultrasonic probe transporter 310 up and down .

The ultrasonic transducer supporting wheel 420 is disposed on the opposite side of the vertical transferring gear 430 for vertically transferring the ultrasonic transducer so as to be closely contacted with the vertical transferring gear 430 for vertically transferring the ultrasonic transducer without being pushed by the ultrasonic transducer transferring belt 310 ) Is installed.

Since the distance traveled up and down in the vertical direction of the ultrasonic probe 230 is measured, an encoder is required in the same direction as the circumferential direction.

When the vertical encoder motor 490 is driven to be connected to the vertical feed gear 430 connected to the rotary shaft of the vertical feed motor 330, the vertical encoder 335 connected to the drive shaft moves the moving distance of the ultrasonic probe feeder 310 As shown in FIG.

The apparatus for testing an automatic ultrasound system 300 according to the present invention inserts the ultrasonic probe 230 into the stud center hole 220 and when the stud fastener 360 is fastened to the upper thread of the stud, do.

6 shows an embodiment in which a stud automatic ultrasonic inspection apparatus 300 according to the present invention is fastened to a stud to perform inspection. When the ultrasonic probe 230 is connected to the ultrasonic transducer transporting rod 310 and inserted into the center hole of the stud and then the automatic inspection apparatus 300 is fastened on the stud 120, the preparation for the inspection is completed.

In this state, when the ultrasonic probe 230 is moved to the end of the stud 120 or the upper inspection start position and the inspection is started, the vertical transfer motor is operated to move the ultrasonic probe 230 to a vertically set position, And a rotation motor is operated to perform ultrasonic defect inspection while rotating 360 degrees.

In order to move the ultrasonic transducer in the vertical direction, the vertical feed motor is operated to move in the vertical direction, and the ultrasonic defect inspection is performed while rotating the rotary motor by 360 degrees.

By repeating the above-described method, the ultrasonic probe 230 can be inspected for the entire length in the vertical direction within the stud center hole.

FIG. 7 shows a configuration diagram of an automatic testing apparatus 300 for testing a test. A motor controller 420 is connected to the vertical feed motor, the rotary motor, the vertical encoder 335 and the rotary direction encoder 345 to drive the motor and drive the motor of the automatic stud inspection apparatus 300, Lt; RTI ID = 0.0 > encoders < / RTI > The received signal is transmitted to the signal collecting PC 510.

The ultrasonic transducer 530 transmits ultrasonic waves generated by the ultrasonic transducer 530 to the ultrasonic probe 230 to emit ultrasonic pulses. The ultrasonic wave emitted from the ultrasonic transducer 530 is reflected from the object to be inspected, And transmits ultrasound signals to a computer (PC) 510 for signal collection and defect inspection.

The PC 510 for signal collection is configured to generate a two-dimensional ultrasonic inspection signal as shown in FIG. 8 by mapping an ultrasonic probe to the ultrasonic signals measured at the respective positions in the vertical direction and the rotational direction position information.

The result of the inspection is the data obtained by using the stud automatic ultrasonic inspection apparatus 300 in which the inner surface of the stud is flattened by using the vertical direction and the rotation direction encoder signal (upper portion (a) in FIG. 8) Is represented by a plane signal having the horizontal direction of the rotation direction [theta] and the vertical direction (y) of the vertical direction of the stud.

And the lower part (b) of FIG. 8 shows the signal with the rotation direction (?) Of the stud and the radius e (r) of the stud, which shows that the signal analysis can be performed visually easily.

The present invention obtains each position data using the vertical encoder and the rotation direction encoder, and stores the reflected ultrasonic signals obtained at the respective positions by mapping them, so that it is easy to know at which position of the stud the defect has occurred.

Also, the data stored in the PC is shown in FIG. 8, so that the defect position can be shown on the monitor so that the defect position can be visually recognized easily.

More specifically, the present invention measures the presence or absence of thread defects of the stud using the technical structure described above.

In the specification of the present invention, the vertical conveying motor and the rotary motor are collectively referred to simply as a motor or a mixture thereof, but it is easily understood by those skilled in the art.

Reactor studs Ultrasonic inspectors and studs are fastened to studs using threaded threads.

7, the signal acquisition and defect inspection computer 510 (PC) controls the motor controller 520 and the ultrasonic transceiver 530, which control the vertical transfer and rotation motor, A control program is mounted so as to perform a technical configuration such as mapping the position data and the received ultrasonic data.

≪ Example 2 >

The second embodiment relates to a nuclear reactor test ultrasonic inspection method of a nuclear power plant using a nuclear reactor test ultrasonic inspection apparatus of a nuclear power plant using the ultrasonic wave of the first embodiment.

(a) inserting the ultrasonic probe 230 into the center hole 220 of the stud, (b) transferring the inserted ultrasonic probe 230 to a vertically set position using a vertical transfer motor And (c) measuring the ultrasound transduced by the ultrasonic transducer in the set vertical direction while rotating the ultrasonic transducer while rotating the ultrasonic transducer using the rotation motor while returning the reflected ultrasonic wave.

The defects of the reactor stud 120 of the nuclear power plant using ultrasonic waves are automatically inspected while repeating the steps (b) and (c).

The method includes the step of measuring a vertical position of an ultrasonic probe by using a vertical encoder in the step (b), and in the step (c), a direction of rotation of the ultrasonic probe And measuring position information.

The reactor stern ultrasonic inspection method includes a step of acquiring respective position data by using a vertical encoder and a rotation direction encoder and mapping and reflecting the reflected ultrasonic signals obtained at the respective positions to acquire the position of defects of the stud accurately .

The reactor stud ultrasonic inspection method is a method in which the stud rotation direction (?) Is a horizontal axis and the vertical direction of the stud is a vertical axis (y) so that the measurement data obtained at positions in the vertical direction and the rotation direction can be visually found easily And displaying the signal on a monitor.

The technical structure which is not described in the nuclear reactor stuck ultrasonic inspection method of the nuclear power plant according to the second embodiment can be easily understood from the reactor stern ultrasonic inspection apparatus described in the first embodiment and therefore it is omitted in order to avoid redundant description.

The present invention relates to a method of inspecting cracks using ultrasonic waves among various methods for examining whether or not the stud 120 connecting the reactor vessel 100 and the reactor upper head 110, which are core facilities of a nuclear power plant, It is possible to quickly and accurately determine whether or not the stud is defective by providing an associated inspection apparatus, which is highly likely to be used industrially.

100; Reactor 110; Reactor head
120; Reactor stud
210; Stud threads 220; Center ball
230; Ultrasonic probe 240; Ultrasonic probe rod
250; Ultrasonic energy 260; Fault signal
270; Shadow signal due to defect 280; Signal reflected from the thread
290; Defect 300; Stud automatic inspection system
310; Ultrasonic probe transporter 320; Ultrasonic probe carrier case
330; A vertical feed motor 335; Vertical encoder
340; A rotation motor 345; Rotation direction encoder
350; A rotary gearbox 360; The stud-
370; A vertically-moving gear box 410; Ultrasonic transducer transfer cylinder
420; An ultrasonic probe feeder support wheel 430; Vertical feed gear
440; Vertical encoder 450; Rotary bearings
460; A rotary gear 470; Rotation gear
475; Rotation direction encoder shaft gear 480; Rotation direction encoder drive gear
490; Vertical encoder motor
510; Signal acquisition and evaluation PC 520; Motor controller
530; Ultrasonic transceiver

Claims (11)

A nuclear reactor (120) ultrasonic inspection apparatus for a nuclear power plant using ultrasonic waves,
An ultrasonic probe 230 for radiating an ultrasonic wave fixed to the bottom edge of the probe rod to the stud and receiving reflected ultrasound waves;
A vertical feed motor 330 for inserting an ultrasonic probe into the center hole 220 of the stud and vertically feeding the inserted ultrasonic probe;
An ultrasonic probe feeder 310 for vertically feeding the ultrasonic probe in conjunction with the vertical feed motor;
A rotation motor 340 for measuring the ultrasonic wave while rotating the vertically transferred ultrasonic probe; And
And an ultrasonic transceiver for transmitting the ultrasonic wave to the ultrasonic probe and receiving the ultrasonic wave received from the ultrasonic probe. The method according to claim 1,
The reactor stud ultrasonic inspection apparatus includes a vertical encoder for measuring a position where the ultrasonic probe moves vertically; And
And a rotation direction encoder for measuring rotation direction position information of the ultrasonic probe. The method of claim 2,
The reactor stud ultrasonic inspection apparatus obtains position data of each position by using a vertical encoder and a rotary direction encoder, maps the reflected ultrasonic signals obtained at respective positions to each other, stores them, and accurately obtains defect position of the stud Reactor stud ultrasonic inspection device. The method of claim 2,
The reactor-stator ultrasonic inspection apparatus uses the stud rotation direction (?) As the horizontal axis and the vertical direction of the stud as the vertical axis (y) so that the data obtained at the respective positions in the vertical direction and the rotation direction can be visually found easily in the defective portion Wherein the signal is displayed on a monitor. The method according to claim 1,
The reactor stern ultrasonic inspection apparatus further comprises a stud fastening part (360) having a female thread formed inside so as to be fastened to a thread formed on the stud. The method according to claim 1,
The ultrasonic probe transporter (310) is configured such that gears horizontally machined in the body are mutually connected to convert the rotational motion into a rectilinear motion in a rack-and-pinion structure, so that the ultrasonic probe is vertically transported vertically. The method according to claim 1,
The stator ultrasonic inspection apparatus includes a computer for signal collection and defect inspection transmitted from an ultrasonic probe, and a plurality of ultrasonic probe modules 500 are arranged and can be inspected at one time. The present invention relates to a method for inspecting a nuclear reactor stern ultrasonic inspection of a nuclear power plant using an ultrasonic wave,
(a) inserting an ultrasonic probe into the center hole (220) of the stud;
(b) transferring the inserted ultrasonic probe 230 to a vertically set position using a vertical transfer motor 330; And
(c) measuring the ultrasonic wave transmitted by the ultrasonic transducer in the set vertical direction while rotating the ultrasonic wave transmitted from the ultrasonic transducer using the rotary motor while using the ultrasonic transceiver,
A method of ultrasonic inspection of a nuclear reactor plant reactor 120 using an ultrasonic wave while repeating steps (b) and (c). The method of claim 8,
The method may further include measuring a vertical position of the ultrasonic probe using the vertical encoder in the step (b). And
And measuring the rotation direction position information of the ultrasonic probe using a rotation direction encoder. The method of claim 9,
The reactor stud ultrasonic inspection method uses the vertical encoder and the rotary direction encoder to acquire respective position data for the ultrasonic probe transporter and map the reflected ultrasonic signals obtained at the respective positions to each other to store the defective position of the stud accurately Further comprising the step of: The method of claim 9,
The reactor stud ultrasonic inspection method is characterized in that the stud rotation direction (?) Is a horizontal axis and the vertical direction of the stud is a vertical axis (y) so that the data obtained at each position in the vertical direction and the rotation direction can be visually found easily in the defect part And displaying the signal on a monitor. The method of claim 1, further comprising the step of:

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