JPH0325743B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure vessel inspection/repair device used for detecting or repairing the wall surface of a nuclear reactor pressure vessel.

Conventionally, there is a flaw detection device shown in FIG. 1 that detects flaws on the wall surface of a nuclear reactor pressure vessel. This flaw detection device 1 has three support legs 5, each having a swinging rail 4 arranged above, attached to a flange 3 formed on the upper part of a reactor vessel 2. A main column 7 hanging down into the container is attached to the three swing legs 6 provided, and a manipulator 10 with a container inspection flaw detection member 9 attached is attached to an elevating member 8 movably attached to the main column 7. are doing. The support legs 5 are each formed into a cylindrical shape, and are provided on the flange portion 3 while being guided by guide stud bolts 11. A support seat is provided at the lower end of the support leg 5, and the support seat is fixed to the guide stud bolt 11 to fix the support leg 5. Moreover, the above-mentioned turning rail 4 has supporting legs 5.
The flange portion 3 is joined to the flange portion 3 via a spacer, and is disposed on the upper inner side of the flange portion 3.

This flaw detection device accurately positions the flaw detection member 9 with respect to the weld line of the container 2, which is the part to be inspected, by positioning the main column 7 using the support legs 5, rails 4, etc. Although it is designed to be installed and maintain its orientation, there is a problem in that it requires labor and time to assemble. This type of equipment also reduces radiation exposure for workers and increases work speed.
There is a demand for something that is as small, simple, and lightweight as possible, but conventional devices have had problems in this respect as well.

The present invention was made in view of the above circumstances, and
The objective is to create an inspection/repair device for flaw detection and repair inside the reactor vessel that can be assembled easily and quickly, is small, simple, lightweight, and has good workability. be.

That is, the present invention provides an apparatus for inspecting and repairing the wall surface of a reactor pressure vessel filled with water by diving into the reactor pressure vessel. a propulsion device that generates propulsive force to cause the submersible to move forward, backward, ascend, descend, and turn; and a position detector that is fixed to the submersible and receives a signal in response to a transmitter outside the pressure vessel. a flaw detection or repair device that is attached to the submersible body and incorporates a flaw detection or repair component; This is an inspection/repair device for inside a pressure vessel, characterized in that it is equipped with an equipment mounting plate for use in a pressure vessel.

The present invention will be described below with reference to illustrative embodiments.

The inspection/repair device 21 according to the present invention is used to detect or repair the inner wall of a nuclear reactor pressure vessel 22, as shown in FIG. This container 22
is located at the bottom of the cavity pit 23 and surrounded by a concrete wall 24. Further, the flange portion 25 at the top of the container 22 is sealed to the bottom of the cavity pit 23, and the container 22 is sealed during work.
2 and cavity pit 23 are filled with water to shield radiation.

A horizontal movement mechanism 26 having a structure capable of moving in two horizontal directions is installed at the top of the cavity pit 23, and a frame 2 is mounted on this horizontal movement mechanism 26.
7 and a control device 28 are provided. This control device 28 is connected to the inspection and repair device 21 via a signal transmission and power line cable 29.
Further, the pedestal 27 includes a transmitter 3 of a position detection sensor.
0 (or a receiver) is attached, and is configured to be able to exchange signals with the inspection/repair device 21 using sound waves (or light, etc.).

The inspection/repair device 21 is configured so that the specific gravity as a whole is 1. As shown in FIG. 3, this inspection/repair device 21 has an equipment mounting plate 32 fixed to the center of the side surface of a submersible body 31, and a probe 33 for flaw detection embedded in this equipment mounting plate 32 (or installing repair equipment). In addition, a balance weight 34 is attached to the side facing the device mounting plate 32 so that the center of gravity is balanced. This submersible body 31 is further equipped with propellers 35 to 38 that move the submersible body 31 in the horizontal direction. Propulsion device 3
5 is capable of freely switching the thrust direction of a propeller or the like, and is freely rotatable about a central axis aa passing through the center of gravity of the submersible body 31. The propulsion device 36 is installed at a position facing the propulsion device 35 described above. The thrusters 37 and 38 can freely switch the direction of thrust, and
Another central axis b- that is perpendicular to the axis and passes through the center of gravity
They are rotatably attached in pairs around b. The submersible body 31 is provided with a receiver 39 . This receiver 39 is for catching the transmitted wave from the transmitter 30, and the receiver 39 and the transmitter 30
This constitutes a position detection system.

Furthermore, as shown in FIG. 4, for example, an attitude detector 40 such as a gyroscope and an attitude stabilizing device 41 are incorporated in the submersible 31. The posture stabilizing device 41 has a high-speed rotating disk 43 attached to motors 42, 42, and the high-speed rotating disk 43 has its rotation axis aligned with the central axis aa (or axis bb). I have to.

Next, the operation of the inspection/repair device configured as described above will be explained. First, move the inspection/repair equipment as follows. The inspection/repair device has a specific gravity of about 1, and the pair of propellers 35, 36 and 37, 38 are arranged symmetrically with respect to the center of gravity. FIG. 5a shows a state in which the thrust forces of the propellers 35 to 38 are applied in the rearward direction, resulting in a forward movement state. In addition, figure b shows the thrusters 35 to 38.
The thrust force is applied in the opposite direction to a in the same figure, resulting in a reverse (reverse) state. Figure c shows the propeller 37,
38 is rotated to generate a downward thrust in the vertical direction, which causes it to rise. d in the same figure shows the thrust force of the thrusters 37 and 38 being generated upward, resulting in a descending state. In this case, since the built-in attitude stabilizing device 41 generates an inertial force, the diving device tries to maintain the same attitude, and even if a rotational moment is generated due to the thrust difference between the propulsors 35 to 38, the attitude Changes (rotations) can be minimized.

Next, a method for changing the posture will be explained.

Since the diving device is dynamically symmetrical with respect to the propellers 35 and 36, when the propulsive forces of the propellers 35 and 36 are applied in opposite directions as shown in Figure 6a, a couple (torque) is generated. rotates laterally around the center of gravity.

At this time, since the posture stabilizing device 41 has a posture holding function, the required torque becomes large, and since the entire device rotates slowly, control becomes easy. Note that controllability can be changed by changing the rotational speed as necessary. Similarly, by acting on the propellers 35 to 38, reverse rotation of the side (b in the figure), forward rotation of the top (c) of the top, reverse rotation of the top (d of the figure), normal rotation of the front (e of the figure), and forward rotation of the front Reverse rotation (f in the same figure) is also possible.

Further, position detection is performed as follows.

The position can be determined, for example, by measuring the arrival time t of the transmitted wave from the transmitter 30 to the receiver 39. That is, if the speed v of the transmitted wave is known, the distance Z can be calculated using the following formula.

Z=v·t However, if the receiver 39 is located at one location, the transmitter 30 will be at the same distance on the spherical surface of Z, so the position of the inspection/repair device 21 will not be uniquely determined. Therefore, normally there are a plurality of receivers 39 (for example, three) at different positions.
will be installed. Due to this, inspection/repair equipment 2
1's position is uniquely determined based on the position of the transmitter 30.

At this time, since the transmitter 30 can be accurately positioned in advance with respect to the furnace vessel 22, the position of the inspection/repair device 21 can be adjusted to the furnace vessel 22 as a result.
You can know about.

Furthermore, for example, if an ultrasonic probe 33 is provided, the lateral length from the wall surface can be easily determined, and this can also be used to determine the distance from the wall.

Next, the attitude detection method will be explained.

The posture is detected by detecting the direction of the inspection/repair device 21 with respect to gravity using the built-in posture detector 40. That is, since the direction of the center of gravity of the furnace vessel 22 is determined in advance (usually vertical), by knowing the deviation, the attitude of the inspection/repair device 21 with respect to the furnace vessel 22 can be determined.

It is also possible to detect the posture with respect to the wall using the probe 33 and the wall.

The horizontal movement mechanism 26 follows the movement of the inspection/repair device 21, and is designed to prevent movement and rotation of the inspection/repair device 21 from being hindered by the reaction force of the cable 29.

By combining the above operations, it becomes possible to control the position and orientation required for flaw detection (or repair).

This method includes a method that uses a position detector for all operations, or a method that uses a position detector to determine the rough position and orientation, and uses the probe 33 in the inspection/repair device 21 for detailed positioning (the probe 33 is used for detailed positioning). There are two possible options: a dedicated detector may also be used.

Next, other embodiments of the present invention will be described.

The inspection/repair device shown in FIG. 7 includes a submersible body 31,
The structures of the propellers 35 to 38, balance weight 34, etc. are similar to those shown in FIG. 3, but the equipment mounting plate 32 is not fixed to the submersible body 31 and is rotatable in two directions. That is, a holding frame 44 is integrally formed on the side surface of the submersible body 31, and a rotation mechanism 45 having a built-in motor is held in this holding frame 44. This rotation mechanism 4
5 has a holding end 46 in the orthogonal direction, and a rotating mechanism 47 is held at the tip of this holding end 46. This rotation mechanism 47 is formed integrally with the device mounting plate 32.

The movement attitude adjustment, position detection, attitude detection, etc. of this inspection/repair equipment are the same as those in Fig. 3, but since the equipment mounting plate 32 is rotatable in two directions, the following abilities are achieved. will be added.

In order to simplify the explanation, FIG. 8 is illustrated in two dimensions. For some reason, the posture of the inspection/repair device 21 may differ from the required angle (vertical here)
If it deviates from the angle, the built-in attitude detector 40 immediately detects the angle. Since this inclination angle β is a deviation from a predetermined angle, the rotation mechanism 47 operates and rotates by the deviation β. By this, the equipment mounting plate 3
2 is returned to the required angle (in this case, perpendicular to the wall surface), and the attitude of the equipment mounting plate does not apparently change.

Generally speaking, attitude control is said to be more difficult than position control. Attitude correction therefore significantly facilitates control of the submersible.

Furthermore, if this method is applied to a method of determining the posture using a wall surface as a reference, the inspection/repair device 21 can only be controlled in position by means of two freely movable rotation mechanisms, making the control even easier.

As explained above, this device allows for arbitrary control of the distance and angle (position of the submersible) between the probe and the surface to be tested, which are required for ultrasonic flaw detection (or repair), and allows for the specified flaw detection function. It is possible to obtain a device that satisfies the following requirements.

Furthermore, since this device does not require any large structure for positioning, it is extremely easy to handle, and is lightweight, so it has remarkable effects such as significantly reducing the work required for the device, etc.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a conventional flaw detection device, Figs. 2 to 8 illustrate a flaw detection and repair diving device according to the present invention, Fig. 2 is an overall schematic diagram, and Fig. 3 is an inspection・An enlarged perspective view showing an example of the repair device, FIG. 4 is a sectional view of the same, FIGS. FIG. 7 is an enlarged perspective view showing another example of the inspection/repair device, and FIG. 8 is an explanatory view showing the action of the equipment mounting plate of the same device. 21... Inspection/repair equipment, 22... Reactor pressure vessel, 23... Cavity pit, 24... Concrete wall, 25... Flange portion, 26...
...Horizontal movement mechanism, 27... Frame, 28... Control device, 29... Cable, 30... Transmitter, 31...
... Submersible body, 32 ... Equipment mounting body, 33 ... Probe, 34 ... Balance weight, 35 to 38 ... Propulsion device, 39 ... Receiver, 40 ... Attitude detection device, 4
1... Attitude stabilizer, 42... Motor, 43...
High-speed rotating disk, 44...holding frame, 45...rotating mechanism, 46...holding end, 47... rotating mechanism.

Claims (1)

[Claims] 1. A device that inspects and repairs the wall surface of a reactor pressure vessel filled with water by diving into the reactor pressure vessel, which includes a submersible body, a submersible body attached to the submersible body so as to be approximately symmetrical vertically and horizontally, and a device that transmits propulsive force. a propulsion device that causes the submersible to move forward, backward, ascend, descend, and turn; and a position detection receiver that is fixed to the submersible and receives a signal in response to a transmitter outside the pressure vessel. , an attitude stabilizing device that is built into the submersible and applies an inertial force to maintain the same attitude; and a flaw detection or repair equipment mounting plate that is attached to the submersible and incorporates a flaw detection or repair member. An inspection/repair device for inside a pressure vessel, characterized by comprising: