JP2023176419A - Lower component attachment/detachment device and method of using lower component attachment/detachment device - Google Patents

Abstract

To provide a lower component attachment/detachment device which can attach/detach not only a motor unit and a motor bracket but also a spool piece and further shorten an attachment/detachment work time of a control rod drive mechanism.SOLUTION: A lower component attachment/detachment device comprises: a first jig 11a which holds a first component being one of lower components 32; a second jig 11b which holds a second component being one of the lower components 32 and can be attached to/detached from the first jig 11a; a third jig 11c which holds a third component being one of the lower components 32 and can be attached to/detached from the first jig 11a; and a support part 12 which supports the first jig 11a in an ascendable/descendable manner and can lift at least one of the first jig 11a, the second jig 11b and the third jig 11c to a height at which a spool piece 32a can be attached/detached.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lower component detaching device and a method of using the lower component detaching device, which is a device for detaching a lower component consisting of a spool piece, a motor bracket, and a motor unit located at the lower part of a control rod drive mechanism main body.

In recent years, improved boiling water reactors (ABWRs) have been equipped with an improved electric drive control rod drive mechanism (which is equipped with a control rod drive mechanism body, a motor unit, a motor bracket, and a spool piece, and which enables minute drive of the control rods). FMCRD (Fine Motion Control Rod Drive mechanism) is adopted.

This improved control rod drive mechanism is removed from the lower part of the reactor pressure vessel for maintenance and inspection during periodic inspections of the reactor, and then reattached to the lower part of the reactor pressure vessel. The work for attaching and detaching this improved control rod drive mechanism must be done in a short period of time because it is carried out in a place with high radiation levels.

In order to cope with this, Patent Document 1 discloses that an auxiliary handling trolley is provided as a small-sized attachment/detachment device in addition to a large-sized attachment/detachment device (exchanger) for the control rod drive mechanism body (hereinafter referred to as the drive mechanism body). Among the components that make up the rod drive mechanism and are located at the bottom of the drive mechanism body (hereinafter referred to as the lower component), the motor unit and motor bracket can be attached and detached using the auxiliary handling cart, reducing the time required for attachment and detachment. It is disclosed that the shortening is attempted.

Japanese Patent Application Publication No. 2000-329892

Lower components of the control rod drive mechanism may include a motor unit and a motor bracket as well as a spool piece coupled to the drive mechanism body. However, in Patent Document 1, the spool piece coupled to the drive mechanism body is attached and detached using a detachment device (exchanger) for the drive mechanism body, as in the past (paragraph 0073). In other words, in Patent Document 1, since it is necessary to take a complicated procedure to attach and detach the spool piece, there is room for improvement in reducing the working time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lower component detaching device that allows not only a motor unit and a motor bracket but also a spool piece to be attached and detached, thereby further shortening the time required for attaching and detaching a control rod drive mechanism.

To achieve the above object, the present invention provides a control rod drive mechanism that includes a control rod drive mechanism main body, a spool piece, a motor bracket, and a motor unit, and which drives a control rod. A lower component detaching device for attaching and detaching a lower component consisting of the motor unit from a reactor pressure vessel, the device comprising: a first jig that holds a first component that is any one of the lower components; and a first jig that holds a first component that is any one of the lower components; a second component that is any one of the lower components; a second jig that is removably attached to the first jig; and a third component that is any one of the lower components; A third jig that can be attached to and detached from the tool and the first jig are supported so as to be movable up and down, and the spool piece attaches and detaches at least one of the first jig, the second jig, and the third jig. A support part that can be raised to a possible height.

According to the present invention, the spool piece can be attached and detached without using the attachment and detachment device of the drive mechanism main body, and the time required for attaching and detaching the control rod drive mechanism can be further shortened. Problems, configurations, and effects other than those described above will be made clear by the following description of the embodiments.

FIG. 2 is a schematic side view showing a state in which a lower component is attached and detached from a control rod drive mechanism by the lower component detachment device according to the first embodiment of the present invention. FIG. 3 is an exploded view of the lower components of the control rod drive mechanism. It is a perspective view of a spool piece. It is a perspective view of a motor unit. FIG. 2 is a schematic side view of a lower component attachment/detachment device according to a first embodiment of the present invention that supports a lower component at a high position. 1 is a schematic side view of a lower component attachment/detachment device according to a first embodiment of the present invention that supports a lower component below; FIG. FIG. 3 is a perspective view of a motor unit, a first jig that holds the motor unit, and a support section that supports the first jig. FIG. 3 is a perspective view of a motor bracket, a second jig that holds the motor bracket and is detachable from the first jig, and a support section that supports the first jig. FIG. 3 is a perspective view of a spool piece, a third jig that holds the spool piece and is detachable from the first jig, and a support section that supports the first jig. FIG. 7 is a schematic side view of a lower component attachment/detachment device according to a second embodiment of the present invention that supports the lower component at a high level. FIG. 7 is a schematic side view showing a state in which a lower component is attached to and detached from a control rod drive mechanism by a lower component detachment device according to a third embodiment of the present invention. FIG. 7 is a schematic side view showing a state in which a lower component is attached to and detached from a control rod drive mechanism by a lower component detachment device according to a fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of lower component attachment/detachment devices according to the first to fourth embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic side view showing a state in which a lower component is attached and detached from a control rod drive mechanism by a lower component detachment device according to a first embodiment of the present invention.

The lower component detachment device 1 is a device for attaching and detaching the lower component 32 of the control rod drive mechanism 3 provided at the bottom of the reactor pressure vessel 2, as shown in FIG. 1, and will be described in detail later.

The reactor pressure vessel 2 is a cylindrical steel structure that houses a fuel assembly, for example, above a cylindrical pedestal space 5 formed surrounded by a pedestal 4 in the reactor containment vessel of an improved boiling water reactor. It is set in. At the bottom of the reactor pressure vessel 2, a plurality of housings 21 protrude downward.

The control rod drive mechanism 3 is a device that controls nuclear fission by moving control rods placed in the center of the fuel assembly into and out of the reactor core. Normally, the control rods are moved in and out of the core by the power of a motor unit 32c, which will be described later. Sometimes the control rods are inserted into the core all at once using water pressure. The control rod drive mechanism 3 includes a drive mechanism main body 31 and a lower component 32.

The drive mechanism main body 31 is a component that grips and moves the control rod, and is housed in the housing 21 , and the lower end of the drive mechanism main body 31 is flange-fastened to the lower part of the housing 21 .

The lower components 32 are a plurality of components provided below the drive mechanism main body 31. FIG. 2 is an exploded view of the lower component 32 of the control rod drive mechanism 3. FIG. As shown in FIG. 2, the lower component 32 includes a spool piece 32a, a motor bracket 32b, and a motor unit 32c.

FIG. 3 is a perspective view of the spool piece 32a. The spool piece 32a is a component that transmits the rotational force generated by the motor unit 32c to the drive mechanism main body 31. A flange portion 32aa is provided at the upper end of the spool piece 32a, and the flange portion 32aa is provided with a plurality of through holes 32ab that penetrate vertically.

Connecting parts (preferably bolts) are inserted from below into the plurality of through holes 32ab, and are screwed into bolt holes (not shown) in the lower part of the drive mechanism main body 31. Thereby, the spool piece 32a is coupled to the drive mechanism main body 31.

The motor bracket 32b is a cylindrical component that connects the spool piece 32a and the motor unit 32c, and is provided with a through hole (not shown) in the center into which a shaft 32ca protruding from the motor unit 32c is inserted. Further, as shown in FIG. 2, the main body 32ba of the motor bracket 32b is provided with a plurality of through holes 32bb that penetrate vertically.

Connecting parts (preferably bolts) are inserted from below into the plurality of through holes 32bb, and are screwed into bolt holes 32ac provided on the lower surface of the spool piece 32a. Thereby, the motor bracket 32b is coupled to the spool piece 32a.

FIG. 4 is a perspective view of the motor unit 32c. The motor unit 32c is a component that has an electric motor as a drive source inside, and as shown in FIG. 4, a shaft 32ca as an output shaft protrudes from the upper end surface. A flange portion 32cb is provided on the upper part of the motor unit 32c, and a plurality of through holes 32cc are provided in the flange portion 32cb to extend vertically through the flange portion 32cb.

Connecting parts (preferably bolts) are inserted from below into the plurality of through holes 32cc, and are screwed into bolt holes 32bd (see FIG. 2) provided on the lower surface of the flange portion 32bc of the motor bracket 32b. Thereby, the motor unit 32c is coupled to the motor bracket 32b.

As shown in FIG. 1, the lower component attachment/detachment device 1 is arranged on a rail 7 laid on a platform 6 which is provided below the reactor pressure vessel 2 in the pedestal space 5 and can be rotated vertically by remote control. ing. The lower component attachment/detachment device 1 includes a holding jig 11 (first jig 11a, second jig 11b, and third jig 11c) that holds the lower component 32, and a support section 12.

FIG. 5 is a schematic side view of the lower component attachment/detachment device 1 according to this embodiment that supports the lower component 32 (spool piece 32a) at a high position. FIG. 6 is a schematic side view of the lower component attachment/detachment device 1 according to this embodiment that supports the lower component 32 (spool piece 32a) below.

Further, FIG. 7 is a perspective view of the motor unit 32c, the first jig 11a that holds the motor unit 32c, and the support section 12 that supports the first jig. FIG. 8 is a perspective view of the motor bracket 32b, the second jig 11b that holds the motor bracket 32b and is detachable from the first jig 11a, and the support section 12 that supports the first jig 11a. FIG. 9 is a perspective view of the spool piece 32a, the third jig 11c that holds the spool piece 32a and is detachable from the first jig 11a, and the support section 12 that supports the first jig 11a.

The lower component attachment/detachment device 1 includes a holding jig 11 that holds one of the lower components 32, and a support section 12 that supports the holding jig 11. Further, the holding jig 11 includes a first jig 11a, a second jig 11b, and a third jig 11c.

The first jig 11a is a holding jig 11 that holds one of the lower components 32 (in this embodiment, the motor unit 32c). As shown in FIG. 7, the first jig 11a connects the motor unit 32c inserted into a central through hole (not shown) of a disc-shaped member to a flange portion 32c provided on the upper side of the motor unit 32c. Hold it at the top.

The upper surface of the first jig 11a has a plurality of through holes 32cc (for example, a plurality of through holes 32cc excluding two diagonal through holes 32cc) provided in the flange portion 32cb of the motor unit 32c. It is preferable to include a pin (not shown).

Moreover, it is preferable that the first jig 11a is provided with two protrusions 11aa that protrude in the outer radial direction from the outer circumferential surface of the disk, symmetrically with respect to the central through-hole. The upper ends of two multistage cylinders 12a forming a support section 12, which will be described later, are coupled to the lower surface of each of the two protrusions 11aa.

The second jig 11b is a holding jig 11 that holds one of the lower components 32 (in this embodiment, the motor bracket 32b). As shown in FIG. 8, the second jig 11b is a disk, and the upper surface of the second jig 11b has two fan-shaped protrusions 11ba that protrude upward along the outer periphery, and the main body 32ba of the motor bracket 32b has two fan-shaped protrusions 11ba. For example, it is preferable to include a plurality of pins (not shown) inserted into the plurality of through-holes 32bb other than the two diagonal through-holes 32bb among the plurality of through-holes 32bb.

Further, the second jig 11b is detachably attached to the first jig 11a, and has a plurality of through holes for inserting a plurality of pins (not shown) provided on the top surface of the first jig 11a. (not shown).

In the motor bracket 32b, a plurality of pins (not shown) provided on the upper surface of the second jig 11b are inserted into a plurality of through holes 32bb excluding two diagonal through holes 32bb, and the second jig 11b It is held by the upper surface of and two fan-shaped protrusions 11ba.

The third jig 11c is a holding jig 11 that holds one of the lower components 32 (in this embodiment, the spool piece 32a), and is detachably attached to the first jig 11a. As shown in FIG. 9, the third jig 11c is a disc-shaped member, and has a central circular hole 11ca and two fan-shaped tools that are symmetrically provided across the circular hole 11ca and communicate with the circular hole 11ca. An insertion hole 11cb, a plurality of pins 11cc projecting upward from the upper surface around the circular hole 11ca, and a plurality of pins (not shown) provided on the upper surface of the first jig 11a are inserted into the insertion hole 11cb. It is preferable to include a through hole (not shown).

A spool piece 32a is inserted into the central circular hole 11ca. The two tool insertion holes 11cb are for inserting and removing a plurality of (two diagonally in this embodiment) connecting parts that connect the spool piece 32a to the drive mechanism main body 31 while holding the spool piece 32a. This is a through hole for insertion.

The tips of the plurality of pins 11cc can be inserted into the plurality of through-holes 32ab other than the two diagonal through-holes 32ab among the plurality of through-holes 32ab provided in the flange portion 32aa of the spool piece 32a. preferable.

Further, the plurality of pins 11cc are provided with a flange-shaped protrusion 11cd (see FIGS. 5, 6, and 9) approximately at the center in the vertical direction. The protrusion 11cd supports the spool piece 32a by abutting the flange 32aa provided at the upper end of the spool piece 32a inserted into the central circular hole 11ca.

With these configurations of the third jig 11c, the spool piece 32a is held by the third jig 11c.

Note that the width of each of the first jig 11a, the second jig 11b, and the third jig 11c is equal to the width of two adjacent control rods of the plurality of control rod drive mechanisms 3 provided at the lower part of the reactor pressure vessel 2. It is preferable that the distance be smaller than the distance between the drive mechanisms 3.

The support part 12 supports the first jig 11a so as to be movable up and down, and supports at least one of the first jig 11a, the second jig 11b, and the third jig 11c (the third jig 11c in this embodiment). The highest spool piece 32a of the lower component 32 is a component that can be raised to a detachable height (a joint between the drive mechanism main body 31 and the spool piece 32a).

As shown in FIGS. 5 and 6, the support section 12 preferably includes, for example, a plurality of (two in this embodiment) multistage cylinders 12a in which a plurality of overlapping cylinders expand and contract vertically. Moreover, it is preferable that the plurality of multi-stage cylinders 12a expand and contract by air pressure. Further, it is preferable that the lower component attachment/detachment device 1 is equipped with an operating device (not shown) that operates the lifting and lowering of the support portion 12 .

Further, the lower component detachment device 1 preferably includes a moving section 13 that freely moves the support section 12 on the platform 6 below the reactor pressure vessel 2, as shown in FIGS. 1, 5, and 6.

As shown in FIGS. 5 and 6, the moving unit 13 includes a flange-equipped wheel 13aa that can be moved manually along a rail 7 laid on a platform 6, and a wheel 13aa for an operator to move the lower component attachment/detachment device 1. It is preferable to include a cart 13a having a grip portion 13ac. Moreover, it is preferable that the truck 13a is provided with a stopper 13ab for fixing the truck 13a that has been moved below the lower component 32.

The moving unit 13 also includes a slide table 13b that can move and position the support unit 12 along a predetermined plane, and a slide table 13b that can rotate the support unit 12 around the vertical direction and position the rotation angle. Preferably, at least one rotary table 13c is provided. In addition, the slide table 13b of this embodiment enables the support part 12 to move along the plane on which the slide table 13b of the cart 13a is placed.

In this embodiment, the slide table 13b is fixed on the cart 13a, the rotary table 13c is fixed on the slide table 13b, and the lower end of the support part 12 is fixed on the rotary table 13c.

The slide table 13b preferably includes a stopper (not shown) for positioning the slid table, and the rotary table 13c preferably includes a stopper (not shown) for positioning the rotation angle of the rotated table. It is preferable to have the following.

Next, a method of using the lower component attachment/detachment device 1 according to this embodiment will be described.

First, a method of using the lower component removal device 1 when removing the lower component 32 from the reactor pressure vessel 2 will be described.

First, the platform 6 is rotated by remote control so that the rail 7 laid on the platform 6 passes below the motor unit 32c to be removed.

Next, the grip portion 13ac attached to the trolley 13a is manually pushed and moved along the rail 7 directly below the motor unit 32c from which the lower component attachment/detachment device 1 is to be removed, and the trolley 13a is fixed by the stopper 13ab.

Next, among the plurality of bolts that connect the motor unit 32c to the motor bracket 32b, a plurality of bolts excluding two bolts arranged diagonally are removed using a tool (for example, a long hexagonal deep socket). remove.

Next, compressed air is injected into the support part 12 using the operating device provided in the lower component detachment device 1 to extend the support part 12, and the motor unit 32c is held by the first jig 11a.

At this time, the motor unit 32c is inserted into the central circular hole (not shown) of the first jig 11a without causing the first jig 11a to interfere with the surrounding control rod drive mechanism 3, and the motor unit 32c is connected to the motor. A plurality of pins provided on the top surface of the first jig 11a are inserted into the through holes 32cc of the motor unit 32c from which the plurality of bolts to be connected to the bracket 32b have been removed, and two pins are inserted to connect the motor unit 32c to the motor bracket 32b. The position and orientation of the support portion 12 are finely adjusted using the slide table 13b and the rotary table 13c so that the bolt can be removed from the tool insertion hole (not shown) of the first jig 11a.

The motor unit 32c is inserted into the circular hole at the center of the first jig 11a, the plurality of pins provided on the top surface of the first jig 11a are inserted into the through hole 32cc of the motor unit 32c, and the flange portion 32cb is inserted into the through hole 32cc of the motor unit 32c. After confirming that the motor unit 32c is in contact with the surface of the first jig 11a and held, the support portion 12 stops extending and the height of the first jig 11a is fixed.

Next, a tool is inserted into the tool insertion hole of the first jig 11a, two bolts connecting the motor unit 32c to the motor bracket 32b are removed, and the motor unit 32c is removed from the reactor pressure vessel 2.

Next, the support portion 12 is retracted to lower the motor unit 32c. Then, the platform 6 is rotated by remote control, the lower component attachment/detachment device 1 is moved along the rail 7 to the repair room 8 (see FIG. 1) where maintenance and inspection of the lower component 32 is performed, and the motor unit 32c is moved to the lower component attachment/detachment device. Take it down from 1.

Next, after the lower component detachment device 1 is returned to the rail 7 on the platform 6, the platform 6 is rotated by remote control so that the rail 7 passes below the motor bracket 32b to be removed.

Next, the lower component attachment/detachment device 1 is manually moved along the rail 7 to just below the motor bracket 32b to be removed, and the cart 13a is fixed by the stopper 13ab.

Next, of the plurality of bolts that connect the motor bracket 32b to the spool piece 32a, all bolts except for the two diagonally arranged bolts are removed using a tool (for example, a long hexagonal deep socket).

Next, the second jig 11b is attached to the first jig 11a by inserting the plurality of pins provided on the upper surface of the first jig 11a into the plurality of through holes provided in the second jig 11b.

Next, compressed air is injected into the support part 12 using the operating device provided in the lower component attachment/detachment apparatus 1 to extend the support part 12, and the motor bracket 32b is held by the second jig 11b.

At this time, the flange portion 32b of the motor bracket 32b is inserted between the two fan-shaped protrusions 11ba of the second jig 11b without causing the first jig 11a and the second jig 11b to interfere with the surrounding control rod drive mechanism 3. A plurality of pins (not shown) provided on the upper surface of the second jig 11b are inserted into the through hole 32bb of the motor bracket 32b after removing the plurality of bolts that connect the motor bracket 32b to the spool piece 32a. The slide table 13b and rotary table 13c are used to attach the support section so that the two bolts that connect the motor bracket 32b to the spool piece 32a can be removed from the tool insertion hole (not shown) of the second jig 11b. Fine-tune the position and orientation of 12.

The flange portion 32bc of the motor bracket 32b is inserted between the two fan-shaped projections 11ba of the second jig 11b, and the plurality of pins provided on the top surface of the second jig 11b are inserted into the through holes 32bb of the motor bracket 32b. After confirming that the lower surface of the flange portion 32bc is in contact with the surface of the second jig 11b and that the motor bracket 32b is held by the second jig 11b, the extension of the support portion 12 is stopped and the second jig is The height of the tool 11b is fixed.

Next, a tool is inserted into the tool insertion hole of the second jig 11b, two bolts connecting the motor bracket 32b to the spool piece 32a are removed, and the motor bracket 32b is removed from the reactor pressure vessel 2.

Next, the support portion 12 is retracted and the motor bracket 32b is lowered. Then, the platform 6 is rotated by remote control, the lower component removal device 1 is moved along the rail 7 to a repair room where maintenance and inspection of the lower component 32 is performed, and the motor bracket 32b is lowered from the lower component removal device 1.

Next, after the lower component detachment device 1 is returned to the rail 7 on the platform 6, the platform 6 is rotated by remote control so that the rail 7 passes below the spool piece 32a to be removed.

Next, the lower component attachment/detachment device 1 is manually moved along the rail 7 directly below the spool piece 32a to be removed, and the cart 13a is fixed by the stopper 13ab.

Next, of the plurality of bolts that connect the spool piece 32a to the drive mechanism main body 31, all but the two bolts arranged diagonally are removed using a tool (for example, a long hexagonal deep socket). .

Next, after removing the second jig 11b from the first jig 11a, the plurality of pins provided on the top surface of the first jig 11a are inserted into the plurality of through holes provided in the third jig 11c. The third jig 11c is attached to the first jig 11a.

Next, compressed air is injected into the support part 12 using the operating device provided in the lower component detachment device 1 to extend the support part 12, and the spool piece 32a is held by the third jig 11c.

At this time, the spool piece 32a is inserted into the central circular hole 11ca of the third jig 11c without causing the first jig 11a and the third jig 11c to interfere with the surrounding control rod drive mechanism 3, and the spool piece 32a is inserted into the circular hole 11ca at the center of the third jig 11c. After removing the plurality of bolts that connect the piece 32a to the drive mechanism main body 31, a plurality of pins 11cc (see FIG. 9) provided on the upper surface of the third jig 11c are inserted into the through hole 32ab of the spool piece 32a. , the support part 12 is fixed by the slide table 13b and the rotary table 13c so that the two bolts that connect the spool piece 32a to the drive mechanism main body 31 can be removed from the tool insertion hole 11cb (see FIG. 9) of the third jig 11c. Fine-tune position and orientation.

The spool piece 32a is inserted into the circular hole 11ca at the center of the third jig 11c, and the plurality of pins 11cc provided on the top surface of the third jig 11c are inserted into the through holes 32ab of the spool piece 32a. After confirming that the lower surface of 32aa abuts the upper end of the projection 11cd provided on the plurality of pins 11cc of the third jig 11c and that the spool piece 32a is held by the third jig 11c, the support part 12 is extended. The height of the third jig 11c is fixed.

Next, a tool is inserted into the tool insertion hole 11cb of the third jig 11c, the two bolts that connect the spool piece 32a to the drive mechanism main body 31 are removed, and the spool piece 32a is removed from the reactor pressure vessel 2.

Next, the support portion 12 is contracted to lower the spool piece 32a. Then, the platform 6 is rotated by remote control, the lower component detachment device 1 is moved into the repair room 8 along the rail 7, and the spool piece 32a is lowered from the lower component detachment device 1 into the repair room.

Each of the lower components 32 is removed from the reactor pressure vessel 2 by the method of using the lower component detachment device 1 described above.

Next, a method of using the lower component detachment device 1 when attaching the lower component 32 to the reactor pressure vessel 2 will be described.

First, the through hole 32ab of the spool piece 32a, which has been maintained and inspected in the repair room, is connected to the upper surface of the third jig 11c attached to the first jig 11a provided at the upper end of the contracted support part 12 of the lower component detachment device 1. The spool piece 32a is held by a third jig 11c.

Next, the lower component attachment/detachment device 1 is returned onto the rail 7 on the platform 6, and the platform 6 is rotated by remote control so that the rail 7 passes below the drive mechanism main body 31 to which the spool piece 32a is attached.

Next, the lower component attachment/detachment device 1 is manually moved along the rail 7 directly below the drive mechanism main body 31 to which the spool piece 32a is attached, and the carriage 13a is fixed by the stopper 13ab.

Next, compressed air is injected into the support part 12 using the operating device provided in the lower component attachment/detachment device 1 to extend the support part 12 and raise the spool piece 32a to the lower end of the drive mechanism main body 31.

At this time, without causing the first jig 11a and the third jig 11c to interfere with the surrounding control rod drive mechanism 3, the spool piece 32a is raised to the lower end of the drive mechanism main body 31, and the two bolts are inserted into the third jig. 2 on the diagonal line provided on the lower surface of the drive mechanism main body 31 via the through hole 32ab provided in the flange portion 32aa of the spool piece 32a that penetrates vertically from the tool insertion hole 11cb (see FIG. 9) of the jig 11c. The position and orientation of the support part 12 is finely adjusted using the slide table 13b and the rotary table 13c so that the support part 12 can be attached to two bolt holes (not shown).

Next, two bolts are screwed from the tool insertion hole 11cb of the third jig 11c through the through hole 32ab of the spool piece 32a into the two diagonal bolt holes on the lower surface of the drive mechanism main body 31, and the spool is removed. The piece 32a is coupled to the drive mechanism main body 31.

Next, the support part 12 is contracted to lower the third jig 11c, and a bolt is screwed into the remaining bolt hole on the lower surface of the drive mechanism main body 31 through the through hole 32ab of the spool piece 32a, thereby driving the spool piece 32a. It is coupled to the mechanism main body 31.

Next, the platform 6 is rotated by remote control, and the lower component detachment device 1 is moved along the rail 7 to the repair room 8.

Next, after removing the third jig 11c from the first jig 11a, the plurality of pins provided on the top surface of the first jig 11a are inserted into the plurality of through holes provided in the second jig 11b. The second jig 11b is attached to the first jig 11a.

Next, the through hole 32bb of the motor bracket 32b that has been maintained and inspected is inserted into a plurality of pins (not shown) provided on the upper surface of the second jig 11b, and the motor bracket 32b is held by the second jig 11b. .

Next, the lower component removal device 1 is returned onto the rail 7 on the platform 6, and the platform 6 is rotated by remote control so that the rail 7 passes below the spool piece 32a to which the motor bracket 32b is attached.

Next, the lower component attachment/detachment device 1 is manually moved along the rail 7 to just below the spool piece 32a to which the motor bracket 32b is attached, and the cart 13a is fixed by the stopper 13ab.

Next, compressed air is injected into the support part 12 using the operating device provided in the lower component attachment/detachment device 1 to extend the support part 12 and raise the motor bracket 32b to the lower end of the spool piece 32a.

At this time, the motor bracket 32b is raised to the lower end of the spool piece 32a without causing the first jig 11a and the second jig 11b to interfere with the surrounding control rod drive mechanism 3, and the motor bracket 32b is attached to the spool piece 32a. A plurality of pins (not shown) provided on the upper surface of the second jig 11b are inserted into the through holes 32bb of the motor bracket 32b after the plurality of bolts to be connected are removed, and the two bolts are inserted into the second jig. Two diagonal bolt holes 32ac are provided on the lower surface of the spool piece 32a through a through hole 32bb that penetrates vertically from the tool insertion hole (not shown) of the tool 11b to the main body 32ba of the motor bracket 32b. (See FIG. 2) The position and orientation of the support part 12 are finely adjusted using the slide table 13b and the rotary table 13c.

Next, a plurality of pins (not shown) provided on the upper surface of the second jig 11b are inserted into the through holes 32bb of the motor bracket 32b after removing the plurality of bolts that connect the motor bracket 32b to the spool piece 32a. .

Next, screw the two bolts from the tool insertion hole of the second jig 11b into the two diagonal bolt holes 32ac on the lower surface of the spool piece 32a through the through hole 32bb provided in the main body 32ba of the motor bracket 32b. At the same time, the motor bracket 32b is coupled to the spool piece 32a.

Next, the support part 12 is contracted, the second jig 11b is lowered, and a bolt is screwed into the remaining bolt hole 32ac on the lower surface of the spool piece 32a through the through hole 32bb of the motor bracket 32b, and the motor bracket 32b is removed from the spool. It is connected to piece 32a.

Next, the platform 6 is rotated by remote control, and the lower component attachment/detachment device 1 is moved along the rail 7 to the repair room. In the repair room, the second jig 11b attached to the first jig 11a provided at the upper end of the shrunk support portion 12 is removed.

Next, the through hole 32cc (see FIG. 4) of the motor unit 32c that has been maintained and inspected is inserted into a plurality of pins (not shown) provided on the top surface of the first jig 11a, and the motor unit 32c is attached to the first jig. It is held with the tool 11a.

Next, after the lower component attachment/detachment device 1 is returned to the rail 7 on the platform 6, the platform 6 is rotated by remote control so that the rail 7 passes below the motor bracket 32b to which the motor unit 32c is attached.

Next, the lower component attachment/detachment device 1 is manually moved along the rail 7 to just below the motor bracket 32b to which the motor unit 32c is attached, and the cart 13a is fixed by the stopper 13ab.

Next, compressed air is injected into the support part 12 using the operating device provided in the lower component attachment/detachment device 1 to extend the support part 12 and raise the motor unit 32c to the lower end of the motor bracket 32b.

At this time, the motor unit 32c is raised to the lower end of the motor bracket 32b without causing the first jig 11a to interfere with the surrounding control rod drive mechanism 3, and the plurality of bolts that connect the motor unit 32c to the motor bracket 32b are removed. A plurality of pins provided on the top surface of the first jig 11a are inserted into the through holes 32cc of the motor unit 32c, and two bolts are inserted into the motor through the tool insertion holes (not shown) of the first jig 11a. The two diagonal bolt holes 32bd of the bolt holes 32bd provided on the lower surface of the flange portion 32bc of the motor bracket 32b are inserted through the vertically penetrating through holes 32cc provided on the flange portion 32cb of the unit 32c (see FIG. 2). ), the position and orientation of the support part 12 are finely adjusted using the slide table 13b and the rotary table 13c.

Next, a plurality of pins provided on the upper surface of the first jig 11a are inserted into the through holes 32cc of the motor unit 32c from which the plurality of bolts that connect the motor unit 32c to the motor bracket 32b have been removed.

Next, the two bolts are inserted through the two tool insertion holes of the first jig 11a through the diagonal through holes 32cc of the multiple through holes 32cc provided in the flange portion 32cb (see FIG. 7) of the motor unit 32c. The motor unit 32c is coupled to the motor bracket 32b by screwing into two diagonally diagonal bolt holes 32bd (see FIG. 2) of the bolt holes 32bd provided on the lower surface of the flange portion 32bc of the motor bracket 32b.

Next, the support part 12 is contracted to lower the first jig 11a, and a bolt is screwed into the remaining bolt hole 32bd on the lower surface of the motor bracket 32b through the through hole 32cc of the motor unit 32c, and the motor unit 32c is connected to the motor. It is coupled to the bracket 32b.

Each of the lower components 32 is attached to the reactor pressure vessel 2 by the method of using the lower component detachment device 1 described above.

(action/effect)
The lower component attachment/detachment device 1 of this embodiment includes a drive mechanism body 31, a spool piece 32a, a motor bracket 32b, and a motor unit 32c. Among the components of a control rod drive mechanism 3 that drives a control rod, the spool piece 32a, the motor bracket 32b and a motor unit 32c, the lower component detachment device 1 is for attaching and detaching a lower component 32 consisting of a motor unit 32b and a motor unit 32c from a reactor pressure vessel 2. 32c), and a second jig that holds one of the lower components 32 (motor bracket 32b in this embodiment) and is detachably attached to the first jig 11a. a third jig 11c that holds a third component (spool piece 32a in this embodiment) that is any one of the lower components 32 and is removably attached to the first jig 11a; 11a so as to be movable up and down, and at least one of the first jig 11a, the second jig 11b, and the third jig 11c is set at a height at which the spool piece 32a can be attached and detached (the coupling between the drive mechanism main body 31 and the spool piece 32a). and a support part 12 that can be raised to a height of 1.

That is, the lower component attachment/detachment device 1 of this embodiment includes the holding jigs 11 (first jig 11a, second jig 11b, and third jig 11c) that hold the motor unit 32c, motor bracket 32b, and spool piece 32a. The holding jig 11 that holds the spool piece 32a can be raised and lowered to a height at which the spool piece 32a can be attached and detached. Therefore, not only the motor unit 32c and motor bracket 32b attached to the lower part of the drive mechanism body 31 but also the spool piece 32a can be attached and detached, so the spool piece 32a can be attached and detached without using the attachment and detachment device of the drive mechanism body 31, and control The time required for attaching and detaching the rod drive mechanism 3 can be shortened.

Furthermore, in the lower component attachment/detachment device 1 of this embodiment, at least one of the first jig 11a, the second jig 11b, and the third jig 11c has a component included in the lower component 32 attached to the component 32 above the component 32. , 32 is provided with a tool insertion hole (for example, tool insertion hole 11cb) for inserting a tool for attaching and detaching a plurality of connected parts connected to the connecting parts.

As a result, in a state where the lower component 32 is held by the first jig 11a, the second jig 11b, and the third jig 11c, a plurality of Since connecting parts (for example, bolts) can be easily attached and detached, the time required for attaching and detaching the control rod drive mechanism 3 can be shortened. Furthermore, the portions where the first jig 11a, the second jig 11b, and the third jig 11c hold the lower component 32 can be made larger regardless of the position of the joined parts, and the lower component 32 can be stably held. .

Furthermore, at least one of the first jig 11a, the second jig 11b, and the third jig 11c of the lower component attachment/detachment device 1 of this embodiment is provided with a plurality of pins, and a plurality of pins are provided on the lower component 32. The component held by the holding jig 11 provided with the pins is provided with a plurality of through holes 32ab, 32bb, and 32cc, and the plurality of pins can be inserted into the plurality of through holes 32ab, 32bb, and 32cc. .

Thereby, each of the first jig 11a, the second jig 11b, and the third jig 11c can position and hold any one of the plurality of lower components 32. Therefore, when attaching and detaching the plurality of connecting parts that connect the lower component 32 to the upper components 31 and 32, the tool insertion hole (for example, the tool insertion hole 11cb), a plurality of through holes 32ab, 32bb, 32cc (see FIGS. 2 to 4) for inserting coupling parts provided in the lower component, and holes provided in the upper components 31, 32 to be coupled to the lower component 32. It becomes easy to align the parts (for example, bolt holes 32ac, 32bd) where the connected parts are connected, and the time required for attaching and detaching the control rod drive mechanism 3 can be shortened.

The lower component detachment device 1 of this embodiment includes a moving section 13 that freely moves the support section 12 on the platform 6 below the reactor pressure vessel 2 . Therefore, the lower component attachment/detachment device 1 can freely move on the platform 6 provided below the reactor pressure vessel 2 in the pedestal space 5, so that the time required for attachment/detachment of the plurality of control rod drive mechanisms 3 can be further shortened. .

In addition, the moving unit 13 of the lower component attachment/detachment device 1 of this embodiment includes a slide table 13b that can move the support part 12 along a predetermined plane, and a slide table 13b that can rotate the support part 12 about the vertical direction as a rotation axis. At least one rotary table 13c is provided.

Thereby, the support part 12 can be slid and rotated so that the first jig 11a, the second jig 11b, and the third jig 11c do not interfere with the control rod drive mechanism 3. In addition, a first jig is installed in the through holes 32ab, 32bb, 32cc (see FIGS. 2 to 4) of the lower component 32 after removing the plurality of connecting parts (bolts) that connect the lower component 32 to the upper components 31, 32. The position and orientation of the support part 12 can be finely adjusted so that a plurality of pins (for example, pin 11cc) provided on the upper surfaces of the second jig 11a, the second jig 11b, and the third jig 11c can be inserted. In addition, through holes 32ab, 32bb, 32cc (see FIGS. 2 to 4) for passing connecting parts (for example, bolts) provided on each of the lower components 32 and portions (see FIGS. 2 to 4) for connecting the connecting parts provided on the upper component ( For example, it is possible to easily align the bolt holes 32ac, 32bd) and a tool insertion hole (for example, tool insertion hole 11cb) provided in the holding jig for inserting a tool.

Further, the support section 12 of the lower component attachment/detachment device 1 of this embodiment includes a plurality of (two in this embodiment) multistage cylinders 12a in which a plurality of overlapping cylinders extend and contract vertically.

The multistage cylinder 12a can obtain a large thrust with a small installation area, and can provide a long operating stroke with a short installation length. Therefore, the mounting area of the support part 12 can be narrowed, and the holding jig 11 can be raised and lowered to a high position easily and quickly, so that the time required for attaching and detaching the plurality of control rod drive mechanisms 3 can be further shortened.

The plurality of multi-stage cylinders 12a of the lower component attachment/detachment device 1 of this embodiment are expanded and contracted by air pressure. Therefore, the risk of failure of the multistage cylinder 12a due to water droplets falling from above can be reduced. In addition, the pedestal space 5 is provided with a port for a service air system that supplies compressed air, and by connecting to that port, compressed air can be easily supplied to the multistage cylinder 12a, so that the pressure supply source can be There is no need to newly provide one, and costs can be reduced.

In the lower component attachment/detachment apparatus 1 of this embodiment, the moving part 13 is provided with wheels 13aa and a grip part 13ac, and the lower component attachment/detachment apparatus 1 is equipped with an operating device for operating the lifting and lowering of the support part 12. Therefore, since machine-side operations can be performed without operating from the remote control room, fine adjustment of the moving part 13 and the support part 12 can be easily made, and the working time can be shortened.

In the lower component attachment/detachment device 1 of this embodiment, the plurality of connecting parts are bolts. Therefore, the operator can manually attach and detach a plurality of connected parts, so even if a plurality of control rod drive mechanisms 3 are provided and the work space is narrow, the task of attaching and detaching a plurality of lower components 32 is easy. can.

In the lower component attachment/detachment device 1 of this embodiment, the width of each of the first jig 11a, the second jig 11b, and the third jig 11c is the same as that of the plurality of control rods provided in the lower part of the reactor pressure vessel 2. It is smaller than the interval between two adjacent control rod drive mechanisms 3 among the mechanisms 3.

Therefore, the holding jig 11 can be raised without interfering with the control rod drive mechanism 3 around the lower component 32 that is removed from the lower part of the reactor pressure vessel 2 for maintenance inspection. Therefore, the lower component 32 can be safely attached and detached.

In addition, the method for using the lower component attachment/detachment device 1 of the present embodiment is that among the components of the control rod drive mechanism 3 that includes the drive mechanism main body 31, spool piece 32a, motor bracket 32b, and motor unit 32c and drives the control rod, the spool A method of using a lower component detaching device 1 for detaching a lower component 32 consisting of a piece 32a, a motor bracket 32b, and a motor unit 32c from a reactor pressure vessel 2, in which a component to be detached from the lower component 32 is attached above it. A plurality of through-holes 32ab, 32bb, and 32cc are provided in the component 32 to be attached and detached for inserting a plurality of coupling parts to be coupled to the component, and the lower component detachment device 1 has a holder for holding the component to be attached and detached. The apparatus includes a jig 11 and a support part 12 that supports the holding jig 11 in a vertically movable manner and is capable of raising the holding jig 11 to a height at which a component 32 to be attached or detached can be detached, and the holding jig 11 is used. When attaching and detaching the component 32 to be attached and detached, the coupling part is inserted into two diagonally located through holes 32ab, 32bb, 32cc among the plurality of through holes 32ab, 32bb, 32cc, and the remaining through holes 32ab, 32bb are inserted. , 32cc, the component 32 to be installed and removed is held by the holding jig 11 with the connected parts removed. The component 32 to be detached is detached by detaching or attaching the connecting part to the component 32.

Thereby, when removing the plurality of lower components 32 from the reactor pressure vessel, it is only necessary to remove two connecting parts arranged diagonally, so that the working time can be shortened.

Furthermore, in the method of using the lower component attachment/detachment device 1 of the present embodiment, when the component 32 to be attached/detached is detached using the holding jig 11, one of the through holes 32ab, 32bb, and 32cc is located on a diagonal line. With the connecting parts inserted into the two through-holes 32ab, 32bb, and 32cc, and the connecting parts removed from the remaining through-holes 32ab, 32bb, and 32cc, a plurality of pins ( For example, a holding jig 11 that holds the component 32 to be installed and removed by inserting the pin 11cc) into the remaining through holes 32ab, 32bb, and 32cc to hold the component 32 to be installed and removed using a plurality of pins (for example, pin 11cc). The target component 32 is moved up and down by the support section 12, and the connecting part is removed or attached to the component 32 to be detached, thereby attaching or detaching the component to be detached.

As a result, when attaching and detaching the plurality of connecting parts that connect the lower component 32 to the upper components 31 and 32, there is a through-hole (for example, the tool insertion hole 11c) provided in the holding jig 11 for inserting a tool. ), a plurality of through holes 32ab, 32bb, 32cc (see FIGS. 2 to 4) provided in the lower component for inserting the connecting parts, and holes provided in the upper components 31, 32 to be combined with the lower component 32. It becomes easy to align the parts (for example, bolt holes 32ac, 32bd) where the connecting parts are connected, and the time required for attaching and detaching the control rod drive mechanism 3 can be shortened.

(Second embodiment)
FIG. 10 is a schematic side view of a lower component attachment/detachment device 201 according to a second embodiment of the present invention that supports the lower component 32 (spool piece 32a) at a high position.

The lower component detaching device 201 according to this embodiment differs from the lower component detaching device 1 according to the first embodiment in a moving section 213. That is, as shown in FIGS. 5 and 6, the moving unit 13 of the lower component attachment/detachment device 1 according to the first embodiment has flanged wheels 13aa that can be moved manually along the rails 7 laid on the platform 6. have On the other hand, the moving unit 213 of the lower component attachment/detachment device 201 according to the present embodiment includes a swinging wheel 213aa that runs on the platform 6.

(action/effect)
The moving unit 213 of the lower component attachment/detachment device 201 according to this embodiment includes a swinging wheel 213aa that runs on the platform 6. As a result, the lower component attachment/detachment device 201 can freely move on the platform 6 instead of on the rails 7 laid on the platform 6, which eliminates the need for turning the platform 6 by remote control, making it easier to move. , travel time can be shortened.

(Third embodiment)
FIG. 11 is a schematic side view showing a state in which the lower component 32 is detached from the reactor pressure vessel 2 by the lower component detachment device 301 according to the third embodiment of the present invention.

The lower component detachment device 301 according to this embodiment differs from the lower component detachment device 1 according to the first embodiment in that it includes a transport cart 314.

The transport vehicle 314 is equipped with a mounting table on which the lower component 32 is placed and wheels, and is capable of transporting the lower component 32 removed from the reactor pressure vessel 2 to the repair room 8 .

(action/effect)
The lower component detachment device 301 according to the present embodiment includes a transport cart 314 that transports the lower component 32 removed from the reactor pressure vessel 2. Thereby, the lower component 32 removed from the reactor pressure vessel 2 can be easily and quickly transported to the repair room 8, and the lower component 32 that has been maintained and inspected in the repair room 8 can be easily and quickly transported from the repair room 8. . Therefore, the efficiency of attaching and detaching the plurality of control rod drive mechanisms 3 can be improved.

(Fourth embodiment)
FIG. 12 is a schematic side view showing a state in which the lower component 32 is detached from the reactor pressure vessel 2 by the lower component detachment device 401 according to the fourth embodiment of the present invention.

The lower component detachment device 401 according to this embodiment is different from the lower component detachment device 1 according to the first embodiment in that a tilt absorbing section 412b that absorbs the tilt of the first jig 11a is provided at the upper end of the plurality of multistage cylinders 12a. This is the point that is provided.

For example, a suspension (suspension) can be used for the tilt absorbing portion 412b.

(action/effect)
In the lower component attachment/detachment device 401 of this embodiment, a tilt absorbing portion 412b that absorbs the tilt of the first jig 11a is provided at the upper end of the plurality of multistage cylinders 12a. Therefore, when holding any one of the lower components 32, the first jig 11a, the second jig 11b, and the third jig 11c can be tilted along the contact surface of the lower component 32. The component 32 can be stably attached and detached.

Note that the present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above have been described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace some of the configurations of each embodiment with other configurations.

Note that the embodiment of the present invention may have the following aspects. That is, although the first jig 11a holds the motor unit 32c, the second jig 11b holds the motor bracket 32b, and the third jig 11c holds the spool piece 32a, the present invention is not limited thereto. . For example, the second jig 11b may hold the motor unit 32c, the third jig 11c may hold the motor unit 32c, and the first jig 11a may hold the spool piece 32a. Further, an embodiment may be adopted in which the third jig 11c holds the motor unit 32c, the first jig 11a holds the motor unit 32c, and the second jig 11b holds the spool piece 32a.

DESCRIPTION OF SYMBOLS 1,201,301,401...Lower component removal device, 2...Reactor pressure vessel, 3...Control rod drive mechanism, 4...Pedestal, 5...Pedestal space, 6...Platform, 7...Rail, 8...Repair room, 11 ...Holding jig, 11a...First jig, 11aa...Protrusion, 11b...Second jig, 11ba...Sectoral projection, 11c...Third jig, 11ca...Round hole, 11cb...Tool insertion hole, 11cc... Pin, 11cd...Protrusion, 12...Supporting part, 12a...Multi-stage cylinder, 13...Moving part, 13a...Dolly, 13aa...Wheel with flange, 13ab...Stopper, 13ac...Gripping part, 13b...Slide table, 13c...Rotary table , 21... Housing, 31... Drive mechanism body, 32... Lower component, 32a... Spool piece, 32aa... Flange portion, 32ab... Through hole, 32ac... Bolt hole, 32b... Motor bracket, 32ba... Main body, 32bb... Through hole, 32bc...Flange part, 32bd...Bolt hole, 32c...Motor unit, 32ca...Shaft, 32cb...Flange part, 32cc...Through hole, 213...Movement part, 314...Transportation cart, 412b...Inclination absorption part

Claims (15)

Among the components of the control rod drive mechanism that drives the control rods, including the control rod drive mechanism main body, spool piece, motor bracket, and motor unit, the lower component consisting of the spool piece, the motor bracket, and the motor unit is inserted into the reactor pressure vessel. A lower component attachment/detachment device for attachment/detachment from the
a first jig that holds a first component that is any one of the lower components;
a second jig that holds a second component that is any one of the lower components and is detachable from the first jig;
a third jig that holds a third component that is any one of the lower components and is detachable from the first jig;
a support portion that supports the first jig so as to be movable up and down, and that is capable of raising at least one of the first jig, the second jig, and the third jig to a height at which the spool piece can be attached and detached;
A lower component attachment/detachment device comprising: The lower component attachment/detachment device according to claim 1,
For inserting into at least one of the first jig, the second jig, and the third jig a plurality of attachment/detachment tools for connecting components that connect components included in the lower component to components above it. A lower component attachment/detachment device characterized in that a through hole is provided. The lower component attachment/detachment device according to claim 1,
At least one of the first jig, the second jig, and the third jig is provided with a plurality of pins,
A component held by the jig provided with the plurality of pins among the lower components is provided with a plurality of through holes,
The lower component attachment/detachment device is characterized in that the plurality of pins can be inserted into the plurality of through holes. The lower component attachment/detachment device according to claim 1,
A lower component attachment/detachment device comprising a moving part that freely moves the support part on a platform below the reactor pressure vessel. The lower component attachment/detachment device according to claim 4,
The moving section is provided with at least one of a slide table that can move the support section along a predetermined plane, and a rotary table that can rotate the support section about the vertical direction. Lower component removal device. The lower component attachment/detachment device according to claim 1,
The lower component attachment/detachment device is characterized in that the support portion includes a plurality of multistage cylinders in which a plurality of overlapping cylinders extend and contract vertically. 7. The lower component attachment/detachment device according to claim 6,
The lower component attachment/detachment device is characterized in that the plurality of multistage cylinders are expanded and contracted by air pressure. The lower component attachment/detachment device according to claim 4,
The moving part is provided with wheels and a gripping part,
A lower component attachment/detachment device, characterized in that it is equipped with an operating device for raising and lowering the support portion. The lower component attachment/detachment device according to claim 2,
A lower component attachment/detachment device, wherein each of the plurality of connecting parts is a bolt. The lower component attachment/detachment device according to claim 4,
The lower component attachment/detachment device is characterized in that the moving unit includes a swinging wheel that runs on the platform. The lower component attachment/detachment device according to claim 1,
A lower component removal/detachment device comprising a transport cart for transporting the lower component removed from the reactor pressure vessel. 7. The lower component attachment/detachment device according to claim 6,
The lower component attachment/detachment device is characterized in that a tilt absorbing portion for absorbing the tilt of the first jig is provided at an upper end of the plurality of multi-stage cylinders. The lower component attachment/detachment device according to claim 1,
The width of each of the first jig, the second jig, and the third jig is equal to that of two adjacent control rod drive mechanisms of a plurality of control rod drive mechanisms provided at the lower part of the reactor pressure vessel. A lower component attachment/detachment device characterized in that the spacing is smaller than the spacing. Among the components of the control rod drive mechanism that drives the control rods, including the control rod drive mechanism main body, spool piece, motor bracket, and motor unit, the lower component consisting of the spool piece, the motor bracket, and the motor unit is inserted into the reactor pressure vessel. 1. A method of using a lower component detachment device for detaching a lower component from the
The target component is provided with a plurality of through holes for inserting a plurality of coupling parts that connect the component to be detached from the lower component to the component above it;
The lower component attachment/detachment device includes:
a jig that holds the component to be attached and detached;
a support part that supports the jig so as to be movable up and down, and is capable of raising the jig to a height at which the component to be attached and detached can be attached and detached;
When attaching or detaching the component to be attached or detached using the jig,
With the coupling parts inserted into two diagonally located through-holes among the plurality of through-holes and the coupling parts removed from the remaining through-holes, the component to be attached and detached is mounted using the jig. hold,
raising and lowering the jig that holds the component to be attached and detached using the support section;
A method of using a lower component detaching device, characterized in that the component to be detached is detached by removing or attaching the connecting part to the component to be detached. A method of using the lower component attachment/detachment device according to claim 14,
When attaching or detaching the component to be attached or detached using the jig,
The connecting parts are inserted into two diagonally located through holes among the plurality of through holes, and the connecting parts are removed from the remaining through holes. inserting a pin into the remaining through hole and holding the component to be removed by the plurality of pins;
raising and lowering the jig that holds the component to be attached and detached using the support section;
A method of using a lower component detaching device, characterized in that the component to be detached is detached by removing or attaching the connecting part to the component to be detached.

Images