JPH01185491A - Incore tightening nut handling tool - Google Patents

Abstract

PURPOSE:To easily make a nut tighten by preparing a long size pipe, a spanner part, a spring mechanism and the like and providing a connecting mechanism for preventing the rotation of a nose piece on a flange in a handling device which is provided on the ascendable flange. CONSTITUTION:The captioned handling tool is formed of a flange and the like in which an ascending device 6 and a rotable handling device 8 are prepared. In the device 8, a handle part 26, a long size pipe 29, a spanner part 30 and a spring mechanism 31 are prepared and a connecting mechanism 9 is provided on the flange 7. Next, the device 8 is allowed to ascend by the device 6, the spanner 30 is engaged with a tightening nut 4, the handle 26 is rotated and the nut 4 is taken out by the spanner 30 as the rotation of a nose piece 5 is prevented by the mechanism 9. The nut 4 is engaged with the spanner 30, the device 8 is allowed to ascend, a nut 7 is screwed in the screw part of a neutron counter 1 and the spanner 30 is rotated to tighten the nut 4 to fix.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention provides a tightening nut for pressurizing and fixing a neutron measurement tube to an in-core flange in a boiling water nuclear reactor!・In particular, it relates to an in-core tightening nut handling tool used for installing and removing a tightening nut.

(Prior art) Generally, in a boiling water reactor, the neutron flux distribution inside the reactor is monitored, and by monitoring the neutron flux distribution, the neutron flux distribution state inside the reactor is always in an appropriate state during the operation period. is maintained. The neutron flux distribution is monitored by a plurality of neutron measurement tubes installed inside the reactor.

The upper part of the neutron measurement tube is elastically engaged with the core upper grid plate by the spring of the spindle part, and the lower part is fixed to the in-core flange by a tightening nut that passes through the guide tube and housing at the bottom of the reactor pressure vessel. .

Several neutron measurement tubes are replaced with new tubes at every regular inspection.

During replacement work, it is necessary to remove and install the tightening nut. Removal and installation of the tightening nut is done manually using a wrench.

(Problems to be Solved by the Invention) As described above, conventionally the tightening nut has been manually attached and removed using a spanner.

However, the tightening position of the tightening nut was narrow because the dust control rod drive rib was surrounded by the structure, and the workability was not good. In particular, in improved boiling water reactors, since the electric motor is installed at the bottom of the control rod drive mechanism, it is practically difficult to install and remove the tightening nuts.

In addition, when installing the tightening nut, the position may vary depending on the control rod drive mechanism or electric voltage.
Because the location was deep and surrounded by JR lines, the area around the tightening nuts was dark, making it difficult to work smoothly.

Furthermore, since the inside of the reactor pressure vessel support pedestal where the tightening nuts are installed has an 8-wire 0 field, it is not desirable to prevent workers from being exposed to radiation if the working time becomes long.

Therefore, there has been a need for a tightening nut handling device that allows the tightening nut to be installed and removed at a location away from the tightening nut installation position.

The present invention has been made in consideration of the above circumstances, and is an in-core tightening nut that is easy to handle, can shorten working time, and can further prevent workers from being exposed to radiation. The purpose is to provide handling tools.

[Structure of the invention]

(Means for Solving the Problems) The in-core tightening nut handling tool according to the present invention has a handle device rotatably provided on a flange that is raised and lowered by an elevator 5A4, and the handle device has a handle portion equipped with a handle. , a long tube extending from the handle portion, a spanner portion provided at the tip of the long tube and capable of fitting into the tightening nut, and a spring mechanism for pressing the tightening nut toward the in-core 7 flange side. , the flange is provided with a connecting mechanism that prevents rotation of the nosepiece.

(Function) When the 7-lunge is raised by the lifting device U, the handle device provided on the flange is also raised at the same time. When the handle device is raised, a 2.2 G spanner section at the tip of the handle device is fitted into a tightening nut. Further, a connecting mechanism provided on the 7 langes fits into the nosepiece.

After the spanner part is fitted into the tightening nut I, when the handle part is rotated, the spanner part rotates through the long tube and the tightening nut is removed. In this case, since the nosepiece is held down by the coupling mechanism, rotation of the nosepiece is prevented.

Next, when attaching a tightening nut, the tightening nut is fitted into the wrench portion at the tip of the handle device, and the flange and handle device δ are raised by the lifting device. When the handle device is raised, the tightening nut comes into contact with the threaded portion of the neutron measurement tube and is pressed by the spring mechanism. When the handle portion is rotated, the spanner portion is rotated via the long tube, and the tightening nut is screwed into the threaded portion of the neutron measurement tube, thereby fixing the neutron measurement tube to the in-core flange.

As described above, according to the present invention, the tightening nut can be installed and removed by simply rotating the handle through the long tube, so that the operator can
There is no need to go into a narrow, dark place surrounded by motors, and you can work in a wide, bright place. Therefore, handling of the tightening grooves 1 to 1 is easy, the working time can be shortened, and the exposure of workers to radiation can be prevented.

(Embodiment) An embodiment of the in-core tightening nut handling tool according to the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 indicates a neutron measuring tube, and this neutron measuring tube 1 passes through a housing (not shown) that is directly connected to the flange 2 of the housing 7, and further passes through a fuel pipe to reach the upper grid plate. The lower end of the neutron measurement tube 1 is once seated with an in-core flange 3 and opened to the outside of the flange. The housing directly connected to the housing flange 2 is welded directly to the lower vessel of the reactor pressure vessel, and further to the guide tube within the reactor pressure vessel.

In-core flange 3 and housing flange 2 are pol 1
- They are fastened together, and a metallic O-ring or the like is used at the joint to seal them. The seat portions of the in-core flange 3 and the neutron measuring tube 1 are fitted conically, and the neutron measuring tube 1 is pressurized and fixed to the in-core 7 flange 3 by the tightening nut 4.

The shape of the tightening nut 4 is such that, for example, a hexagonal portion has the required length, and the rest is cylindrical. The tightening nut 4 is screwed onto a threaded portion of the neutron measurement tube 1, and its front surface abuts the in-core flange 3 and is sealed by an O-ring.

The lower end of the tightening nut 4 is sealed with the neutron measurement tube 1 by an O-ring. When replacing the neutron measuring tube 1, the nose piece 5 is screwed into the lower end opening. Lead terminals of each sensor extending from the lower end of the neutron measuring tube 1 are accommodated within the nose piece 5 .

In the in-core tightening nut handling tool, a handle device 8 is rotatably provided on an upper flange 7 that is raised and lowered by a hydraulic cylinder structure 6 as a lifting device, and a connecting mechanism that prevents rotation of the nose piece 5 is provided on this upper flange. 9 is provided.

The hydraulic cylinder mechanism 6 as a lifting device is equipped with a hydraulic cylinder 10. The hydraulic cylinder 10 is formed watertight, and the interior thereof is partitioned into two chambers by a piston 11. An end plug 12 is watertightly fitted to the lower end of the hydraulic cylinder 10, and the hydraulic cylinder mechanism 6 is vertically supported by a base 13 fixed to the lower end of the end plug 12.

Hydraulic hoses 1, 4, and 15 are connected to each ice chamber of this hydraulic cylinder 11 through pipe joints 20, 21 through coverrs 16, 17, and 18° 19, respectively.
The piston 11 is moved up and down within the hydraulic cylinder 10 by pressure water supplied from 4.15.

FIG. 2 is a view taken along the line ■-■ in FIG. 1.

An end plug 12 is bolted to the center of the base 13, and a mounting hole 22 is provided around the base 13.

A shaft 23 extends from the piston 11, and the upper flange 7 is fixed to the tip of the shaft 23 with a nut 24. The upper flange 7 is provided so as to be movable up and down along a guide plate 25 extending from the hydraulic cylinder 10.

Is there a handle on the upper flange 7? A 26 is a large number of steel balls 2
It is rotatably provided via 7. The handle portion 26 has a handle 28 for operation. A long tube 29 extends from the handle portion 26, and a spanner portion 30 is fixed to the tip of the long tube 29. The spanner part 30 has a shape that can be fitted into the tightening nut 4.

The long tube 29 is provided with a spring mechanism 31 that presses the tightening nut 4 toward the inner core 7 flange 3 side. The spring mechanism 31 includes a spring receiver 32 fixed to the inner surface of the long tube 29, and is supported by the spring receiver 32.
A spring 33 that generates a pressing force and a sleeve 34 that transmits the pressing force of the spring 33 to the tightening nut 4 are provided.

The coupling mechanism 9 is equipped with a strut 35, which is fixed to the upper flange 7 via a short tube 36. Post 35
has a square hole, for example, and is adapted to fit into a connector 37 having a square outer shape screwed onto the nose piece 5.

FIG. 3 is a waterway system diagram that supplies pressure water to the hydraulic cylinder mechanism 6. The waterway system is equipped with water 140, and this water tank 40 is equipped with a pump 41.

The pump 41 is driven by air supplied through a three-piece set (filter, oiler, regulator) 42 and through a throttle valve 43a, and is configured to assemble and pressurize the water in the water tank 40. The pump 41 is connected to the water pressure hose 14 via a throttle valve 43b and a water pressure gauge 44 through a turntable 45 and a turnaround 46. Further, the water pressure hose 15 is connected to the water WI 40 via coverlets 47 and 48.

Note that the throttle valve 43b is a return valve, and when it is open, high-pressure water or water in the circuit returns to the water tank 40. Further, reference numeral 49 is a water level gauge, and reference numeral 50 is an air pressure gauge dedicated to the regulator. The water pressure gauge 44 is used exclusively for high pressure water.

Kabra 16, 17.18, 19.45.46.47 above
．． 48 can be freely attached and detached, and when removed, the internal pressure of the hydraulic hose 14 and 15 and the hydraulic cylinder 1
A non-return system is used to maintain zero internal pressure.

Next, the operation of the above embodiment will be explained.

During the replacement work of the neutron measurement tube 1, an in-core tightening nut handler was placed inside the reactor pressure vessel support pedestal,
Install it directly below the nose piece 5.

Also, one end of the hydraulic hose 14, 15 is carried and introduced into the reactor pressure vessel support into the destal. Water pressure hose 14.
The other end of 15 is connected to water PI 40 installed outside the reactor containment vessel.

To connect the water pressure hoses 14 and 15, first connect the cover 47 of the water pressure hose 15 to the cover 46 on the pump side, and then
8 is connected to the cover 19 on the hydraulic cylinder 10 side. On the other hand, connect the cover 45 of the water pressure hose 14 to the cover 4 on the water tank 40 side.
8 and connect the cover 16 to the cover 17 on the hydraulic cylinder 10 side.

When pressurized water is supplied from the pump 41 to the hydraulic cylinder 10 through the hydraulic hose 15, the piston 11 rises, and the shaft 23, upper flange 7, and handle device 8 connected to the piston 11 rise. When the handle assembly v18 rises, the spanner part 30 tightens the screw l-4.
, and the tip of the spanner part 30 comes into contact with the inner-core flange 3. When the spanner part 30 comes into contact with the in-core flange, the scale of the water pressure gauge 44 will rise rapidly, so remove the coverlet 45°46.47.48.

Then, the worker rotates the handle portion 26 using the handle 28. When the handle portion 26 is rotated, the wrench portion 30 is rotated and the tightening nut 4 is removed since the handle portion 26, the elongated tube 29, and the spanner portion 30 are fixed to rotate together.

In this case, the tightening nut 4 can be removed via the long tube 29 by rotating the handle part 26, so there is no need for a worker to enter the narrow space between the sides of the control and rod drive g1. The tightening nut 4 can be removed simply by operating the handle portion 26 in the wide space below the inter-control rod fII mechanism.

After removing the tightening nut 4, replace the cover 47 with the cover 4.
8 and the cover 45 is connected to the cover 46 to supply pressurized water from the pump 41 to the hydraulic cylinder 10 through the hydraulic hose 14, and the handle device 8 is lowered.

At this time, the tightening nut 4 is lowered onto the sleeve 34 in a dented state.

When attaching the tightening nut 4, the tightening nuts 1 to 4 are placed on the sleeve 34 of the handle device 8, and the handle device 8 is raised by the hydraulic cylinder mechanism 6 in the same manner as described above. When the handle fitting ■8 reaches its upper limit, tighten the tightening nut 4.
comes into contact with the threaded part of the neutron measurement tube 1, and the spring mechanism 3
1 is pressed toward the in-core flange 3 side.

Then, when the handle part 26 is rotated with the tightening lug (.4) pressed by the spring mechanism 31, the tightening lug (.4) is rotated.
The nut 4 is screwed onto a threaded portion of the neutron measurement tube 1 and fixes the neutron measurement tube 1 to the in-core flange 3. After the tightening nut 4 is attached, the handle device 8 is lowered by the hydraulic cylinder groove 6, and the next operation is performed.

Thus, according to the above embodiment, the hydraulic cylinder mechanism 6
The handle device 8 can be raised and lowered by
Since the tightening nut 4 can be installed and removed using the spanner part 30 via the long tube 29 by simply operating the handle part 26, the work H does not have to enter the narrow space next to the rod drive unit. Therefore, the tightening nut 4 can be installed and removed extremely easily. Therefore, the work time can be shortened, and work (l) can be prevented from being compromised.In addition, electric combat is provided at the bottom of the control rod drive mechanism as in the improved boiling water reactor. Even if the structure is different, the use of the long elongated tube 29 makes it possible to easily attach and detach the tightening nut 4.

In the above embodiment, the hydraulic cylinder i structure 6 is provided as the elevating device, but the present invention is not limited thereto, and a hydraulic or pneumatic cylinder mechanism or N motive may be used as the elevating device.

(Effects of the Invention) The in-core tightening nut handling tool according to the present invention has a handle device rotatably provided on the flange that is raised and lowered by the lifting bag δ, and the handle device includes a handle portion equipped with a handle, and a handle portion provided with the handle. The flange is provided with a long tube extending from the section, a spanner section provided at the tip of the long tube and capable of fitting into a tightening nut, and a spring mechanism for pressing the tightening nut toward the inner flange. Since the connecting gate structure is provided to prevent rotation of the nosepiece, handling of the tightening nut is facilitated and the working time is shortened. Therefore, it is possible to prevent workers from being exposed to radiation.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the in-core tightening nut handling tool according to the present invention, and FIG.
The t-line arrow view and FIG. 3 are waterway system diagrams in the above-mentioned eggplant example. 1... Neutron measurement tube, 3... In-core flange, 4
...Tightening nut, 5...Nose piece, 6...Elevated fitting, 7...Upper flange, 8...Handle fitting, 9...Connection-like groove, 26... Handle part, 28...
・Handle, 29...long tube, 30...spanner part,
31...Spring mechanism.

Claims (1)

[Claims] A handle device is rotatably provided on a flange that is raised and lowered by the lifting device, and the handle device includes a handle portion provided with a handle, a long tube extending from the handle portion, and a handle device provided at the tip of the long tube. It is characterized by being equipped with a spanner part that can be fitted into the tightening nut, a spring mechanism that presses the tightening nut toward the inner flange, and a connecting mechanism that prevents rotation of the nose piece on the flange. In-core tightening nut handling tool.