JP4352255B2 - Underwater inspection device and underwater inspection method - Google Patents

Description

  The present invention relates to an underwater inspection apparatus and an underwater inspection method for inspecting the state of a lining container such as a nuclear power plant and a spent fuel reprocessing facility in a water storage state.

  When a defect such as a crack generated on the surface of the structure is detected, if there is dirt inside the structure, an accurate detection result cannot be obtained.

  As a conventional underwater inspection device, in order to open the inspection box to the atmosphere at a depth of 10 m or more, water in the inspection box is sucked with a jet pump using compressed air as a driving fluid, and the water is discharged to the jet pump outlet. A tube was attached, and bubbles were ejected from the jet pump and pumped to the surface of the water through a drainage tube for local drainage. After that, a large-scale apparatus has been proposed in which the atmosphere in the inspection box is sucked using a vacuum pump to maintain a negative pressure state and is dried to the inside of the defect using an induction heating coil (see, for example, Patent Document 1).

  In addition, an operator dives into the water, covers the inspection target part with a simple cover, cleans the inspection target part with an ultrasonic vibrator in the cover, injects permeate into the inspection target part, removes the cover, and develops. An underwater penetrant inspection method has been proposed in which a putty containing an agent is pressed against and contacted with an inspection target part, the putty is peeled off, and a defect state is observed (for example, see Patent Document 2).

Japanese Laid-Open Patent Publication No. 9-218167 (Pages 4-5, FIGS. 1 and 2) JP-A-8-128995 (pages 3-5, FIGS. 1-8)

  The underwater inspection apparatus of Patent Document 1 must prepare a jet pump and an induction heating coil, and the apparatus configuration is large, the inspection target portion needs to be dried, and the inspection requires a long time.

  In the underwater penetrant inspection method of Patent Document 1, an operator is submerged in water. For example, in a nuclear power plant and a spent fuel reprocessing facility, it is desirable to avoid an operation where an operator dives in the water as much as possible for the safety of the operator, even though the water absorbs and blocks neutrons.

  An object of the present invention is to provide an internal volume having means for reliably removing clogging of a defect without diving the operator even if a penetration defect such as a base material of a lining in water and a welded portion are clogged. Underwater inspection in a small inspection box.

  In order to solve the above-mentioned problem, the present invention places an inspection box containing an ultrasonic transducer inside and having a seal packing on the opening end surface on an inspection target part, and makes the inside of the inspection box have a negative pressure and Drain the internal water until the ultrasonic transducer is not exposed, drive the ultrasonic transducer without exposing it from the internal water of the inspection box to clean the inspection target, and clean the inspection target with air bubbles generated during cleaning An underwater inspection device and an underwater inspection method for detecting completion and inspecting a defect of a cleaned inspection target part are proposed.

  According to the present invention, the inspection box can be easily installed even under water at a depth of 10 m or more, and the ultrasonic vibrator is submerged in a state where the ultrasonic vibrator is submerged using a simple local drainage means using a water jet ejector. The inspection box is maintained by draining, ultrasonic cleaning, clogging of defects generated in the welded portion of the lining container and the like can be easily removed, and the penetration defect of the welded portion can be detected.

  Next, an embodiment of the underwater inspection apparatus according to the present invention will be described with reference to FIGS. Here, the present invention will be described by taking as an example the case of inspecting the sealing performance of the welded portion of the lining in the spent fuel storage pool.

  FIG. 1 is a system diagram showing the configuration of an embodiment of the underwater inspection apparatus according to the present invention.

  The underwater inspection apparatus of the present embodiment is roughly divided into an inspection box 1 in which one end is opened and the other is sealed and accommodated in the ultrasonic vibrator 76, a negative pressure generator 11, and a water ejection ejector 29.

  The inspection box 1 is provided with a seal packing on the open end face, is connected to the negative pressure line 2, and houses an ultrasonic transducer 76 on the lower side. The ultrasonic vibrator 76 is driven by an ultrasonic oscillator 77.

  The examination box 1 is equipped with an underwater television camera 32 as an imaging means, and the captured image can be observed on a television monitor 38.

  The negative pressure generator 11 supplies negative pressure into the examination box 1 via the negative pressure line 2, and drives the water injection ejector 29 by the high pressure supply water pump 17 using the water supplied from the water source 74. .

  The negative pressure generator 11 includes a negative pressure pressure gauge 31, a pressure gauge valve 17, a vent valve 16, and a connection coupler 12 on the negative pressure line 2 side, and a connection coupler 14, a flow meter 35, and a water supply amount on the water supply line 6 side. An adjustment valve 18, a water supply branch hose 71, and a water supply pressure gauge 36 are provided.

  The negative pressure generator 11 includes a high pressure feed water pump 27, a feed water source side valve 24, connection couplers 21 and 23, and a hose 22 on the supply line 20 side, and a priming water valve 26 and a connection coupler 28 on the priming line 25 side. The drain valve 15 and the connection coupler 28 are provided on the water supply drain line 72 side, and the water supply valve 19 and the connection coupler 28 are provided on the inspection box water supply line 73 side.

  On the other hand, the inspection target portion is a plurality of linings 30 placed in close contact with the inside of the concrete housing 67. Adjacent linings 30 are welded so that water inside does not leak out of the lining 30. A leakage detection groove 68 is provided on the side of the concrete casing 67 of the welding line 63 that welds the adjacent lining 30. In the unlikely event that a penetration defect occurs in the welding of the welding line 63, the leaked water will leak into the leakage detection groove 68. Since 68 accumulates in the flow glass 34 of the leakage detection system 33, it is found that a penetration defect has occurred.

  Next, a more detailed structure of the underwater inspection apparatus of the present invention will be described.

  FIG. 2 is a side sectional view showing the structure of the (single window type) underwater inspection apparatus according to the present invention in more detail, and FIG. 3 shows the structure of the (single window type) underwater inspection apparatus according to the present invention in more detail. FIG. 4 is a front view, and FIG. 4 is a back view showing the structure of the (single window type) underwater inspection apparatus according to the present invention in more detail.

  A unit of a sealed window 49 made of a transparent acrylic plate or the like that allows the inside of the examination box 1 to be visually recognized on the surface opposite to the opening end face of the examination box 1, and an underwater camera 32 unit comprising a TV camera and an illumination lamp in the vicinity of the sealed window 49. And has. A slide guide 55 is provided along the vicinity of the sealed window 49 of the examination box 1, a slider 60 is attached to the slide guide 55, a camera holder 56 is attached to the slider 60, and a camera 30 is attached to the camera holder 56. Is provided with an operation rope 59.

  An ultrasonic transducer 76 is fixed inside the inspection box 1 on the side opposite to the opening end face 45. A connection cable 78 is connected to the ultrasonic transducer 76, and a transparent acrylic plate 49 for monitoring the inside of the examination box 1 is provided as a sealed window on the opposite side of the opening end face 45 side of the examination box 1.

  The inspection box 1 is supported by a handling tong 39 attached to the casing, and the handling tong 39 protrudes above the pool water 41 and is fixed by an inspector or a handling machine.

  On the lower side of the inspection box 1, a hole 64 for connecting the water jet ejector 29 and the inspection box 1 and an ejector connection pipe 53 are installed. The water jet ejector 29 is fixed to the inspection box 1 by an ejector mounting bracket 54 and is connected to the negative pressure generator 11 through the water supply line 6.

  FIG. 5 is a perspective view showing a state in which the sealing performance of the penetration defect portion is inspected by the inspection box 1 of FIG. The state of FIG. 5 shows a state where water is not completely discharged from the examination box 1, that is, a state where the ultrasonic transducer is submerged.

  In this state, a negative pressure is generated when the jet water flow is discharged from the water ejecting ejector 29, the water in the inspection box 1 is sucked out from the ejector connection pipe 53, and a negative pressure is generated inside the inspection box 1, The inspection box 1 is tightly adhered to the weld line 63 to which the lining 30 is joined by the packing 46 and sealed.

  Next, a procedure for inspecting the sealing performance with the underwater inspection apparatus of the present invention will be described.

Procedure 1: Preparatory work The connecting coupler 4 of the hose 3 is connected to the connecting coupler 5 on the inspection box 1 side on the negative pressure line 2 side of the inspection box 1 of the underwater inspection apparatus. The connecting coupler 9 of the hose 8 is connected to the connecting coupler 7 on the water supply line 6 side of the inspection box 1. The inspection box 1 is set as the inspection target portion of the wall surface of the underwater lining 30.

  The connecting coupler 10 of the hose 3 is connected to the connecting coupler 12 on the negative pressure generator 11 side on the negative pressure line 2 side connected to the inspection box 1. The connecting coupler 13 of the hose 8 is connected to the connecting coupler 14 on the negative pressure generator 11 side on the water supply line 6 side connected to the inspection box 1.

  The drain valve 15 on the water supply line 6 side of the negative pressure generator 11 is closed, the vent valve 16 on the negative pressure line 2 side is closed, the pressure gauge valve 17 on the negative pressure line 2 side is opened, and the amount of water supply on the water supply line 6 side is adjusted. Close the valve 18, close the water supply valve 19 in the inspection box on the water supply line 6 side, connect the connection coupler 23 of the hose 22 to the connection coupler 21 on the supply line 20 side, set the hose 22 to the water source 74, and supply water source The side valve 24 is opened, the priming valve 26 on the priming line 25 side is closed, and the high-pressure feed pump 27 is activated.

Procedure 2: Air release on the negative pressure line 2 side Next, air on the negative pressure line 2 side is released. The connecting coupler 10 on the hose 3 on the negative pressure line 2 side is removed, connected to the connecting coupler 28 on the water supply line 6 side, the water supply valve 19 in the inspection box on the water supply line 6 side is opened, and the air inside the inspection box 1 is removed. Unplug. After completion of air bleeding, the water supply valve 19 in the inspection box on the water supply line 6 side is closed, the connection coupler 10 of the hose 3 is removed, and the connection coupler 10 of the hose 3 is connected to the connection coupler 12 on the negative pressure line 2 side.

Procedure 3: Inspection Next, inspect underwater. When the vent valve 16 on the negative pressure line 2 side is closed, the water supply adjustment valve 18 on the water supply line 6 side is opened, and the water injection ejector 29 is supplied with water, the water inside the inspection box 1 is sucked and the inside of the inspection box 1 is negative pressure The inspection box 1 comes into close contact with the wall surface of the underwater lining 30.

  The negative pressure state inside the examination box 1 is confirmed by the negative pressure gauge 31 of the negative pressure generator 11, and the state of the internal water 42 inside the examination box 1 is confirmed by the television monitor 38 connected to the underwater television camera 32.

  Next, while continuously operating the high-pressure feed water pump 27, the vent valve 16 on the negative pressure line 2 side is slightly opened to drain the internal water 42 of the inspection box 1. At this time, the internal water 42 in the examination box 1 is drained while confirming the drop in water level on the television monitor 38. The ultrasonic transducer 76 in the examination box 1 is drained until it is not exposed, the vent valve 16 is closed, and the examination box 1 is held.

  In order to inspect the presence or absence of a clogged weld penetration defect 40 on the wall surface of the lining 30 where the inspection box 1 is installed, the ultrasonic oscillator 77 is turned on, and the welding portion of the lining 30 where the inspection box 1 is installed penetrates the weld. When the defect 40 portion is cleaned with ultrasonic waves, clogging of the weld portion penetration defect 40 portion is eliminated, and bubbles 43 are generated in the internal water 42 in the inspection box 1 from the weld portion penetration defect 40 of the lining 30. The bubble 43 is confirmed on the television monitor 38, and it can be determined that the cleaning is completed.

  That is, when the ultrasonic transducer 76 provided inside the inspection box 1 ultrasonically cleans the penetration defect 40 of the welded portion clogged with the weld line 63, the clogging of the penetration defect 40 of the welded portion is eliminated, It can be determined that the cleaning is completed by confirming on the TV monitor 38 that bubbles 43 are generated in the internal water 42 of the inspection box 1 from the penetration defect 40 in the welded portion of the lining 30.

Procedure 4: Opening the inspection box 1 Next, the inspection box 1 is opened. Close the drain valve 15 on the water supply drain line 72 side, close the water supply amount adjustment valve 18 on the water supply line 6 side, remove the connection coupler 10 of the hose 3 from the connection coupler 12 on the negative pressure line 2 side on the negative pressure line 2 side, On the negative pressure line 2 side, the connection coupler 10 of the hose 3 is connected to the connection coupler 28 of the water supply line 73 in the inspection box, the water supply valve 19 in the inspection box is opened, and water is injected into the inspection box 1. When the inspection box 1 is separated from the wall surface of the lining 30, the high-pressure feed water pump 27 is stopped, and the pipes and devices are collected in the reverse procedure of the preparatory work.

Procedure 5: Confirmation of leaked water by leak detection system Note 4: After the inspection box 1 is opened, if the leak water is confirmed by the flow glass 34 of the leak detection system 33 provided in the lining container 66, the examination box 1 is installed. It can be determined that the clogging of the penetration defect 40 in the welded portion has been eliminated.

  These steps complete the work.

  The structure of the examination box 1 is not limited to the above shape, and can be appropriately selected according to the shape of the installation portion of the lining surface.

  In the above embodiment, one inspection box 1 is used. However, when the sealing performance of the lining container is inspected, in order to remove the clogging of the defective portion, the target portion in water (the clogged portion of the weld penetration defect is clogged). If a plurality of inspection boxes 1 are mounted, it is possible to inspect the sealing performance at a plurality of locations and shorten the inspection time.

  In other words, an inspection box containing an ultrasonic transducer inside and having a seal packing on the opening end face is placed on the inspection target part, the pressure inside the inspection box is made negative, and the ultrasonic transducer is not exposed to the water inside the inspection box Drain to the state, drive the ultrasonic transducer in a state where it is not exposed from the internal water of the inspection box, clean the inspection target part, detect the completion of cleaning of the inspection target part by bubbles generated during cleaning, and clean the inspection target part If the underwater inspection method for inspecting defects is performed in parallel, the period of periodic inspections can be shortened.

It is a systematic diagram which shows the structure of one Example of the underwater inspection apparatus by this invention. It is a sectional side view which shows the structure of the underwater inspection apparatus (one-window type) by this invention in detail. It is a front view which shows the structure of the underwater inspection apparatus (one window type) by this invention in detail. It is a back view which shows the structure of the underwater inspection apparatus (one window type) by this invention in detail. It is a perspective view which shows the state which test | inspects the sealing performance of a penetration defect part with the test | inspection box 1 of FIG.

Explanation of symbols

1 Inspection Box 2 Negative Pressure Line 3 Hose 4, 5 Connection Coupler 6 Water Supply Line 7, 9 Connection Coupler 8 Hose 10, 12, 13, 14 Connection Coupler 11 Negative Pressure Generator 15 Drain Valve 16 Bend Valve 17 Pressure Gauge Valve 18 Water Supply Adjustment valve 19 Water supply valve 20 Supply line 21, 23 Connection coupler 22 Hose 24 Supply water source side valve 25 Nominal water line 26 Nominal water valve 27 High pressure supply water pump 28 Connection coupler 29 Water injection ejector 30 Inner lining 31 Negative pressure pressure gauge 32 Underwater TV camera 33 Leakage detection system 34 Flow glass 35 Flow meter 36 Supply pressure gauge 37 Camera cable 38 Television monitor 39 Handling tong 40 Weld penetration defect 41 Pool water 42 Internal water 43 Bubble 45 Open end face 46 Seal packing 47 Packing groove 48 Pin 49 Transparent Acrylic plate 50 packing 51 Holding plate 52, 61, 62 Fixing bolt 53 Ejector connection pipe 54 Ejector mounting bracket 55 Slide guide 56 Camera holder 57 Camera unit 58 Connection bracket 59 Operation rope 60 Slider 63 Welding wire 64, 65 Hole 66 Lined container 67 Concrete casing 68 Leakage Detection groove 70 Water surface 71 Water supply branch hose 72 Water supply drain line 73 Water supply line 74 in inspection box Water source 75 Center line 76 Ultrasonic vibrator 77 Ultrasonic oscillator 78 Connection cable

Claims (3)

  An inspection box that contains an ultrasonic vibrator inside and has a seal packing on an opening end face that is in contact with the inspection target portion, a water jet ejector that drains the internal water of the inspection box to a state where the ultrasonic vibrator is not exposed, and A negative pressure generator that supplies negative pressure to the inside of the inspection box and supplies the water injection ejector to the water injection ejector, and drives the ultrasonic transducer in a state where the inspection object is not exposed from the internal water of the inspection box. An underwater inspection device that includes an ultrasonic oscillator for cleaning, and that cleans an inspection target part prior to defect inspection. The underwater inspection apparatus according to claim 1,
An imaging means for detecting the level of internal water to be drained through a transparent window formed on the opposite side of the opening end surface of the inspection box, and detecting completion of cleaning of the inspection target portion by bubbles generated during cleaning, and An underwater inspection apparatus comprising a monitor. Place the inspection box with the ultrasonic vibrator inside and the seal packing on the opening end face on the inspection target part,
Drain the internal water of the inspection box to a state where the ultrasonic vibrator is not exposed while making negative pressure inside the inspection box,
Driving the ultrasonic transducer in a state where it is not exposed from the internal water of the inspection box, and cleaning the inspection target portion,
Detecting the completion of cleaning of the inspection target part by bubbles generated during cleaning,
An underwater inspection method for inspecting a defect of the cleaned inspection target part.

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