JP6927934B2 - ICM handling support ring - Google Patents

Description

The present invention relates to an ICM handling support ring.

Conventionally, a neutron measuring instrument has been installed in a boiling water reactor of a nuclear power plant to monitor nuclear fission in the reactor. Neutron measuring instruments are replaced during periodic inspections of nuclear power plants using multiple handling cranes, the reactor building overhead crane and the fuel changer.

Specifically, the neutron measuring instrument needs to be installed in the reactor from the upper side of the pressure vessel in the reactor building. In addition, since the neutron measuring instrument is long and easily bends, it is stored in a special container. Then, with the dedicated container suspended in the reactor using an overhead crane in the reactor building, the neutron measuring instrument is attached to each installation position using the installation suspension attached to the fuel changer. ..

Japanese Unexamined Patent Publication No. 2001-108784

By the way, in the periodic inspection of a boiling water reactor of a nuclear power plant, it is necessary to replace the neutron measuring instrument installed in the reactor. However, as mentioned above, the replacement work of the neutron measuring instrument is a critical path for periodic inspections because it occupies multiple handling cranes for the reactor building overhead crane and the fuel changer at the same time. ..

The present invention has been devised in view of the above circumstances, and an object of the present invention is to provide an ICM (In Core. Monitor) handling support ring that does not use a plurality of handling cranes at the same time when exchanging a neutron measuring instrument.

In order to solve the above problems, the ICM handling support ring of the present invention is installed on the flange surface of the reactor pressure vessel, and has a hole for avoiding contact with the stud bolt of the reactor pressure vessel and the reactor pressure vessel. It is provided with a hanging part for attaching to the flange surface of the reactor and a bracket part for attaching a dedicated container for accommodating the neutron meter side unit or other devices.

According to the present invention, it is possible to provide an ICM handling support ring that does not use a plurality of handling cranes at the same time when exchanging a neutron measuring instrument.

The schematic side view which shows the state which the ICM handling support ring of Embodiment 1 which concerns on this invention is installed in a reactor pressure vessel. The perspective view of the ICM handling support ring of Embodiment 1. FIG. Top view of the ICM handling support ring of the first embodiment. FIG. 6 is a schematic view showing a state in which a steam dryer / steam separator handling tool suspended by an overhead crane is fitted into a hole of a suspension portion when the ICM handling support ring moves. The perspective view of the state where the special vessel is attached to the bracket of the ICM handling support ring placed on the reactor pressure vessel. Side view of the state where the dedicated vessel is attached to the bracket of the ICM handling support ring placed on the reactor pressure vessel. The perspective view which shows the internal state of the case in a special container. FIG. 4C is a view taken along the line I. FIG. 4C is a view taken along the line II. Top view of the ICM handling support ring with the circular cylinders installed at two of the holes removed. The perspective view of the state where the ICM handling support ring with the circular cylinder removed is placed on the reactor pressure vessel with the stud bolt removed. The perspective view of the positioning method using the upper guide tube of the ICM handling support ring of Embodiment 2. FIG. 2 is a side sectional view of a positioning method using the upper guide tube of the ICM handling support ring of the second embodiment. Enlarged perspective view near the guide of the ICM handling support ring. The perspective view which shows the ICM handling support ring of Embodiment 3. Top view showing the ICM handling support ring of Embodiment 3. FIG. 7A is a view taken along the line IV. FIG. 8A is a view taken along the line V. FIG. 3 is a perspective view showing a state in which a dedicated container for storing a neutron measuring instrument and a service device are attached to the ICM handling support ring of the third embodiment. The figure which shows the situation which the special container is hung on the detachable bracket. The figure which shows the situation which the service device is hung on the detachable bracket. The perspective view which shows the ICM handling support ring of Embodiment 4. Top view showing a state in which the ICM handling support ring of the fourth embodiment is separated. FIG. 11A is a view taken along the line VI of FIG. 11A showing a joint portion of the ICM handling support ring of the fourth embodiment. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel. The schematic diagram which shows the process of installing the neutron measuring instrument of Embodiment 5 inside the reactor pressure vessel.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
The present invention relates to a periodic inspection technique in a nuclear reactor.

<< Embodiment 1 >>
FIG. 1 is a schematic side view showing a state in which the ICM handling support ring 1 of the first embodiment according to the present invention is installed in the reactor pressure vessel 201.

FIG. 2A is a perspective view of the ICM handling support ring 1 of the first embodiment, and FIG. 2B is a top view of the ICM handling support ring 1 of the first embodiment.
The ICM handling support ring 1 is a means for attaching to the inside of the reactor pressure vessel 201.

As shown in FIGS. 2A and 2B, the ICM handling support ring 1 of the first embodiment has a ring shape. As shown in FIG. 1, the ICM handling support ring 1 is installed on the flange surface 201f of the reactor pressure vessel 201.

The inner diameter n1 (FIG. 2B) of the ICM handling support ring 1 has a dimension equal to or larger than the inner diameter n2 (FIG. 4A) of the reactor pressure vessel 201. As a result, it is possible to prevent the ICM handling support ring 1 from falling into the reactor pressure vessel 201. Note that FIG. 4A shows a case where the inner diameter n1 of the ICM handling support ring 1 and the inner diameter n2 of the reactor pressure vessel 201 are substantially the same.

Two stud bolts 202 are erected above the flange surface 201f of the reactor pressure vessel 201.

As shown in FIGS. 2A and 2B, the ICM handling support ring 1 has a ring-shaped flange 101, a hanging portion 103, and a bracket 104.
A dedicated container 301 (see FIG. 4A) for storing the neutron measuring instrument 304 (see FIGS. 4C to 4E) is attached to the flange 101.

As shown in FIG. 2B, the flange 101 is provided with a plurality of circular holes 102 on the entire circumference so as to avoid interference between the stud bolt 202 (see FIG. 1) of the reactor pressure vessel 201 and the ICM handling support ring 1. Has been done.
Further, the ICM handling support ring 1 is formed with a hanging portion 103 so that it can be moved.

As shown in FIG. 3, the suspension portion 103 is formed in a convex shape upward from the ICM handling support ring 1, and a hole 103a penetrating in the horizontal direction is formed in the center thereof. FIG. 3 is a schematic view showing how the steam dryer / steam separator handling tool 403 suspended by the overhead crane 501 is fitted into the hole 103a of the suspension portion 103 when the ICM handling support ring 1 moves. be.
When the ICM handling support ring 1 moves, as shown by the arrow α1 in FIG. 3, the steam dryer / steam separator handling tool 403 suspended by the overhead crane 501 is fitted into the hole 103a of the suspension portion 103. The ICM handling support ring 1 is lifted.

As shown in FIG. 2A, the ICM handling support ring 1 is provided with a circular cylinder 105 at two of a plurality of circular holes 102. The ICM handling support ring 1 is positioned horizontally with respect to the reactor pressure vessel 201 by guiding the cylinder 105 of the ICM handling support ring 1 to the stud bolt 202 (see FIG. 1) of the reactor pressure vessel 201. Will be done. That is, the cylinder 105 suppresses the ICM handling support ring 1 from moving horizontally from the reactor pressure vessel 201, facilitating positioning.

The flange 101 is provided with a bracket 104. The bracket 104 has a plate-shaped mounting portion 104a extending upward along the edge of the inner peripheral circle of the flange 101, and a brace-shaped supporting portion 104b that supports the mounting portion 104a. The bracket 104 is fixed to the flange 101 by bolting or the like.

4A and 4B are perspective views and side views of a state in which the dedicated container 301 is attached to the bracket 104 of the ICM handling support ring 1 mounted on the reactor pressure vessel 201, respectively.

The bracket 104 is for attaching various devices such as a dedicated container 301 in which the neutron measuring instrument 304 (see FIGS. 4C to 4E) is stored. 4C, 4D, and 4E are a perspective view showing the internal state of the case 301c in the dedicated container 301, an arrow view in the I direction of FIG. 4C, and an arrow view in the II direction of FIG. 4C, respectively.
The neutron measuring instrument 304 is thin and long, and easily bends. Therefore, it is stored in the dedicated vessel 301 before being inserted into the reactor pressure vessel 201.

For example, the dedicated container 301 of the neutron measuring instrument 304 is attached to the bracket 104 of the flange 101. The bracket 104 prevents the dedicated container 301 from shifting in the inward and outward directions of the reactor pressure vessel 201. That is, in the bracket 104, the mounting portion 104a extends upward so that the dedicated container 301 does not fall inward where the core (not shown) of the reactor pressure vessel 201 is located.

Further, the bracket 104 prevents the dedicated container 301 from coming off from the flange 101 when the neutron measuring instrument 304 (see FIGS. 4C to 4E) is taken out from the dedicated container 301.

As shown in FIG. 4B, a steam separator 401 is installed above the core inside the reactor pressure vessel 201. The steam separator 401 is a device that removes condensed water because steam containing condensed water significantly reduces turbine efficiency when it enters the turbine.
As shown in FIG. 4A, the ICM handling support ring 1 is placed on the reactor pressure vessel 201 with the holes 102 and the cylinder 105 guided by the stud bolt 202.

Then, a special container 301 in which the neutron measuring instrument 304 is housed is hung on the bracket 104 of the ICM handling support ring 1.
The outer shell of the special container 301 is covered with a case 301c.

Inside the case 301c of the dedicated container 301, as shown in FIGS. 4C to 4E, since the neutron measuring instrument 304 is a long object, a plurality of neutron measuring instruments 304 are assembled in the storage container 303 of the dedicated container 301. ..
After the dedicated container 301 is hung on the bracket 104, the neutron measuring instrument 304 is taken out from the dedicated container 301 and installed at an arbitrary place inside the reactor pressure vessel 201.

In this way, in order to attach the dedicated container 301 to the inside of the reactor pressure vessel 201, the ICM handling support ring 1 is attached to the flange surface 201f of the reactor pressure vessel 201 in advance.
On the other hand, the ICM handling support ring 1 is provided with a flange 101 and a bracket 104 provided on the flange 101 so that the dedicated container 301 can be attached from above. Then, the special container 301 is attached to the bracket 104 of the flange 101 by using the overhead crane 501 (see FIG. 12) or the fuel handling machine 502 (see FIG. 17) of the reactor building described later.

FIG. 5A is a top view of the ICM handling support ring 1 with the circular cylinders 105 (see FIG. 4A) installed at two of the holes 102 removed, and FIG. 5B shows the circular cylinders 105 removed. It is a perspective view of the state in which the ICM handling support ring 1 is placed on the reactor pressure vessel 201 from which the stud bolt 202 (see FIG. 4A) has been removed.

As shown in FIGS. 5A and 5B, the ICM handling support ring 1 without the circular cylinder 105 is placed in the reactor pressure vessel 201 to which the stud bolt 202 is not attached.

According to the above configuration, since the neutron measuring instrument 304 is taken out from the dedicated container 301 attached to the ICM handling support ring 1, it is possible to configure the configuration so that a plurality of handling cranes (501, 502) are not used at the same time. Therefore, it is possible to avoid contact between the overhead crane 501 of the reactor building and the fuel changer 502 due to simultaneous operation during the work inside the reactor during the periodic inspection of the reactor.

Therefore, it is possible to reduce the possibility of the related equipment falling into the reactor due to the collision between the plurality of handling cranes of the overhead crane 501 of the reactor building and the fuel handling machine 502.
Further, by handling the dedicated container 301 of the neutron measuring instrument 304, it is possible to suppress the falling of the suspended load into the furnace due to the movement of the load.

Further, since the ICM handling support ring 1 has an inner diameter that is substantially the same as the inner diameter of the reactor pressure vessel 201 or larger than the inner diameter of the reactor pressure vessel 201, it reaches the fuel arranged in the core even during transfer. Is suppressed.
Therefore, in order to handle the dedicated container 301 of the neutron measuring instrument 304, the suspended load may fall into the furnace due to the movement of the load, or the overhead crane 501 of the reactor building and the plurality of handling cranes of the fuel changer 502 may collide with each other. It is possible to provide an ICM handling support ring 1 that reduces the possibility of the related equipment falling into the reactor due to the crane.

<< Embodiment 2 >>
6A and 6B are perspective views and side sectional views of a positioning method using the upper guide tube 203 of the ICM handling support ring 2 of the second embodiment, respectively. FIG. 6C is an enlarged perspective view of the ICM handling support ring 2 near the guide 106.

The ICM handling support ring 2 of the second embodiment is provided with a guide 106 for positioning the ICM handling support ring 2 in the horizontal direction of the reactor pressure vessel 201.

As shown in FIGS. 6A and 6B, an upper guide pipe 203, which is a guide for positioning the ICM handling support ring 2, is fixed to the reactor pressure vessel 201.

As shown in FIG. 6C, the guide 106 is formed with a through hole 106a having an opening on the center side penetrating in the vertical direction with a size guided by the upper guide pipe 203. The guide 106 is formed with a central taper 106a1 and a lower taper 106a2 so as to be connected to the through hole 106a.
The central taper 106a1 has an inclined surface that is connected to the through hole 106a and gradually expands toward the center of the ICM handling support ring 2.

The lower taper 106a2 has an inclined surface that is connected to the through hole 106a and gradually expands toward the lower side of the ICM handling support ring 2.
In the ICM handling support ring 2 of the second embodiment, as in the first embodiment, when the ICM handling support ring 2 is attached to the flange surface 201f (see FIG. 1) of the reactor pressure vessel 201, the stud bolt 202 (see FIG. 1) is attached. The ICM handling support ring 2 is positioned with respect to the reactor pressure vessel 201 using the above.

On the other hand, when all the stud bolts 202 (see FIG. 1) have been removed from the reactor pressure vessel 201, ICM handling is performed on the upper guide pipe 203 fixed to the reactor pressure vessel 201 as shown in FIG. 6A. By guiding the guide 106 of the support ring 2, the ICM handling support ring 2 can be positioned.

The guide 106 of the ICM handling support ring 2 has a downward taper 106a2 (see FIG. 6C) of an inclined surface that is continuous with the through hole 106a and gradually expands downward. Therefore, when the ICM handling support ring 2 is placed on the flange surface 201f of the reactor pressure vessel 201 from above, the lower taper 106a2 of the guide 106 is placed on the upper guide pipe 203 of the reactor pressure vessel 201 (see FIG. 6C). Will be guided.
Therefore, the through hole 106a of the guide 106 is smoothly fitted into the upper guide pipe 203, and the ICM handling support ring 2 can be easily positioned on the flange surface 201f of the reactor pressure vessel 201.

Further, since there is a central taper 106a1 (see FIG. 6C) of the inclined surface that is connected to the through hole 106a and gradually expands toward the central side, the reactor pressure vessel 201 is moved in the vertical direction through the vicinity of the upper guide pipe 203. It is possible to prevent various devices such as the steam separator 401 (see FIG. 12) and the steam dryer 402 (see FIG. 12) that are taken in and out of the reactor pressure vessel 201 from coming into contact with the guide 106. The steam dryer 402 removes small water droplets contained in the steam when the steam passes through.

Since the bracket portion (bracket 104) is formed so that each work position and a device for assisting the work in the furnace there can be attached, the work in the furnace can be smoothly performed at each work position.
According to the above configuration, the ICM handling support ring 2 of the device that assists the operation in the reactor so that the steam dryer 402 and the steam separator 401 do not come into contact with the guide 106 when the steam dryer 402 and the steam separator 401 are carried in and out during the operation in the reactor. Can be obtained.

<< Embodiment 3 >>
7A and 7B are a perspective view and a top view showing the ICM handling support ring 3 of the third embodiment, respectively.
In the ICM handling support ring 1 of the first embodiment, the bracket portion is composed of only two brackets 104, but in the ICM handling support ring 3 of the third embodiment, as shown in FIGS. 7A and 7B, a large number of attachment / detachment are performed. The bracket 108 has a shape to which a container or device used in the reactor pressure vessel 201 can be attached. As a result, various containers and devices can be attached to the detachable bracket 108.

8A is a view taken in the IV direction of FIG. 7A, and FIG. 8B is a view taken in the V direction of FIG. 8A.
The detachable bracket 108 has a plate-shaped mounting portion 108a extending upward along the edge of the inner peripheral circle of the flange 101, and a brace-shaped supporting portion 108b that supports the mounting portion 108a.

As shown in FIGS. 8A and 8B, the mounting portion 108a and the supporting portion 108b are fastened and fixed to the ICM handling support ring 3 with bolts b1.

FIG. 9 is a perspective view showing a state in which the dedicated container 301 for storing the neutron measuring instrument 304 (see FIGS. 4C and 4D) and the service device 302 are attached to the ICM handling support ring 3.
The attachment / detachment bracket 108A of the ICM handling support ring 3 has a shape in which a dedicated container 301 in which the neutron measuring instrument 304 is stored can be hung.

FIG. 10A is a diagram showing a situation in which the dedicated container 301 is hung on the detachable bracket 108A, and FIG. 10B is a diagram showing a situation in which the service device 302 is hung on the detachable bracket 108B.

As shown in FIG. 10A, the dedicated container 301 is provided with an engaging portion 301a having a recess 301a1 that is engaged with the detachable bracket 108A. By moving the dedicated container 301 and fitting the attachment portion 108a1 of the attachment / detachment bracket 108A into the recess 301a1 of the dedicated container 301 as shown by the arrow α2 in FIG. 10A, the dedicated container 301 can be inserted into the ICM handling support ring via the attachment / detachment bracket 108A. It is attached to 3.

The attachment / detachment bracket 108B of the ICM handling support ring 3 shown in FIG. 10B has a shape in which the engaging portion 302a having the recess 302a1 of the service device 302 can be hung. By moving the service device 302 as shown by the arrow α3 in FIG. 10B and fitting the attachment portion 108b1 of the attachment / detachment bracket 108B into the recess 302a1 of the service device 302, the service device 302 is inserted into the ICM handling support ring via the attachment / detachment bracket 108B. It is attached to 3.

Examples of the service device 302 include, for example, a main steam line plug, an ICM bending device, an underwater luminaire, and the like.
The main steam line plug is a device that seals the main steam relief valve and parts of the main steam line (main steam isolation valve, etc.) so that water does not flow from the reactor pressure vessel 201 to the main steam line during periodic inspections. Is.

The ICM bending device bends the neutron measuring instrument 304 so that the used (irradiated) neutron measuring instrument 304 can be moved from the inside of the reactor pressure vessel 201 to the spent fuel pool at a shielded water depth. Make it smaller.
The underwater illuminator is a device that illuminates the inside of the reactor pressure vessel 201 underwater.

According to the configuration of the third embodiment, by making the detachable bracket 108 (108A, 108B) into a shape to which various containers and devices can be attached, various desired containers and devices can be attached to the ICM handling support ring 3. .. Therefore, the work in the furnace can be performed smoothly.

<< Embodiment 4 >>
FIG. 11A is a perspective view showing the ICM handling support ring 4 of the fourth embodiment, and FIG. 11B is a top view showing a state in which the ICM handling support ring 4 of the fourth embodiment is separated.
Although the ICM handling support ring 1 of the first embodiment illustrates an integrated type, the ICM handling support ring 4 of the fourth embodiment shown in FIGS. 11A and 11B has a structure in which the ICM handling support ring 4 of the fourth embodiment is integrally assembled before use as a divided configuration. ..

The ICM handling support ring 4 includes four first ring 4A, a second ring 4B, a third ring 4C, and a fourth ring 4D shown in FIG. 11B.
The first ring 4A, the second ring 4B, the third ring 4C, and the fourth ring 4D have a shape obtained by dividing the ICM handling support ring 1 of the first embodiment into substantially four parts.

Similar to the first embodiment, the ICM handling support ring 4 has a plurality of circular holes 102 formed on the entire circumference of the flange 101. Further, the ICM handling support ring 4 has four suspension portions 103 and two brackets 104.

FIG. 11C is a view taken along the line VI of FIG. 11A showing the joint portion of the ICM handling support ring 4 of the fourth embodiment.
The third ring 4C is formed with an upper convex portion 4c1 extending toward the second ring 4B and a concave portion 4c2 recessed below the convex portion 4c1. Further, the second ring 4B is formed with a lower convex portion 4b1 extending toward the third ring 4C and a concave portion 4b2 recessed above the convex portion 4b1. That is, the convex portion 4c1 above the third ring 4C and the concave portion 4c2 below, and the concave portion 4b2 above the third ring 4B and the convex portion 4b1 below are fitted to each other.

A screw hole 109 is formed through the convex portion 4c1 above the third ring 4C and the convex portion 4b1 below the second ring 4B.
With this configuration, the convex portion 4c1 above the third ring 4C and the concave portion 4c2 below, and the concave portion 4b2 above and the convex portion 4b1 below the second ring 4B are fitted to each other, and the bolt 110 is inserted into the screw hole 109. By tightening, the third ring 4C and the second ring 4B are connected.

Similarly, a joint portion between the first ring 4A and the second ring 4B, a joint portion between the third ring 4C and the fourth ring 4D, and a joint portion between the fourth ring 4D and the first ring 4A are also configured. ..

With the above configuration, an ICM handling support ring 4 having a first ring 4A, a second ring 4B, a third ring 4C, and a fourth ring 4D is configured.
Therefore, the ICM handling support ring 4 is divided and configured, and is assembled before the work. Therefore, the ICM handling support ring 4 can be easily stored and cleaned.

<< Embodiment 5 >>
In the fifth embodiment, the step of installing the neutron measuring instrument 304 inside the reactor pressure vessel 201 by using the ICM handling support ring 1 of the first embodiment will be described.

12 to 19 are schematic views showing a step of installing the neutron measuring instrument 304 of the fifth embodiment inside the reactor pressure vessel 201.

As shown in FIG. 12, inside the reactor pressure vessel 201, a core 201a on which fuel rods are placed is provided at the lowermost portion.
A steam separator 401 and a steam dryer 402 are attached above the core 201a.

First, the ICM handling support ring 1 is held by the steam dryer / steam separator handling tool 403 suspended by the overhead crane 501. Then, the stud bolt 202 (see FIG. 1) of the reactor pressure vessel 201 is inserted into the cylinder 105 (see FIG. 1) of the ICM handling support ring 1, and the ICM handling support ring 1 is inserted into the flange surface 201f of the reactor pressure vessel 201. Place it.

Subsequently, as shown in FIG. 13, the steam dryer 402 is lifted by the steam dryer / steam separator handling tool 403 suspended from the overhead crane 501 and moved to the outside of the reactor pressure vessel 201.
Subsequently, as shown in FIG. 14, the worker P attaches the neutron measuring instrument 304 to the storage container 303 of the dedicated container 301. Then, the sling 305 of the overhead crane 501 is attached to one side of the dedicated container 301 to which the neutron measuring instrument 304 is attached.

Subsequently, as shown in FIG. 15, the worker P attaches the guide rope 306 of the overhead crane 501 to the other side of the dedicated container 301 to which the neutron measuring instrument 304 is attached. Then, the dedicated container 301 to which the neutron measuring instrument 304 is attached is suspended from the overhead crane 501 by the sling 305 and the guide rope 306.

Subsequently, as shown in FIG. 16, the overhead crane 501 is used to move the dedicated container 301 to which the neutron measuring instrument 304 is attached above the core 201a. Then, the dedicated container 301 to which the neutron measuring instrument 304 is attached is engaged with the bracket 104 (see FIG. 1) of the ICM handling support ring 1 above the core, and the dedicated container 301 is attached to the ICM handling support ring 1 above the core.

Thus, as shown in FIG. 17, before using the fuel handling machine 502, the dedicated container 301 in which the neutron measuring instrument 304 is housed is placed inside the reactor pressure vessel 201 by using the overhead crane 501 of the reactor building. Install it. After that, the fuel handling machine 502 approaches the dedicated container 301 without using the overhead crane 501 of the reactor building, and the neutron measuring instrument handling tool 308 held by the suspension tool 307 is attached to the neutron measuring instrument 304.

Then, as shown in FIG. 18, the worker P releases the lock of the dedicated container 301 with respect to the neutron measuring instrument 304 by the operation pole 309.
After that, as shown in FIG. 19, the neutron measuring instrument 304 is taken out from the dedicated container 301 by the fuel handling machine 502 via the hanging tool 307 and the neutron measuring instrument handling tool 308, and installed at a desired position near the core 201a. ..

According to the above configuration, as a structure in which the dedicated container 301 is attached to the ICM handling support ring 1 by using the overhead crane 501 or the fuel handling machine 502, a method in which both of the plurality of handling cranes 501 and 502 are not used at the same time is adopted. As a result, either one of the cranes 501 and 502 can be used for another operation. Therefore, the period of regular inspection is expected to be reduced.

From the above, by adopting a method that does not use a plurality of handling cranes 501 and 502 at the same time, one crane can be used for another work, so that the period of periodic inspection is expected to be reduced.
In addition, improvement of working environment and reduction of radiation exposure can be expected. Further, the safety of the reactor can be ensured by not performing the work in close proximity to the overhead crane 501 of the reactor building and the fuel changer 502, and by simplifying the work.

1, 2, 3, 4 ICM handling support ring 102 hole 103 hanging part 104 bracket (bracket part)
106 Guide 108, 108A, 108B Detachable bracket (bracket part)
201 Reactor pressure vessel 201f Flange surface 202 Stud bolt 203 Upper guide pipe (upper guide rod)
301 Dedicated container 302 Service equipment (equipment)
304 Neutron measuring instrument

Claims (6)

Installed on the flange surface of the reactor pressure vessel,
A hole for avoiding contact with the stud bolt of the reactor pressure vessel,
A suspension part for attaching to the flange surface of the reactor pressure vessel,
An ICM handling support ring characterized by a dedicated container for accommodating neutron measuring instruments or a bracket for attaching other devices. In the ICM handling support ring according to claim 1,
The ICM handling support ring is an ICM handling support ring having an inner diameter larger than the inner diameter of the flange surface of the reactor pressure vessel. In the ICM handling support ring according to claim 1,
An ICM handling support ring including a guide guided by an upper guide rod provided in the reactor pressure vessel. In the ICM handling support ring according to claim 1,
The bracket portion is an ICM handling support ring characterized in that a device for assisting work in the furnace is attached. In the ICM handling support ring according to claim 1,
The ICM handling support ring is an ICM handling support ring characterized in that it is divided into a plurality of components. In the ICM handling support ring according to claim 1,
The ICM handling support ring is an ICM handling support ring having an inner diameter substantially the same as the inner diameter of the upper flange portion of the reactor pressure vessel.

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