JPS62269092A - Control rod rack - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control rod rack for a boiling water nuclear reactor, and particularly to a control rod rack suitable for streamlining control rod replacement work and shortening the process.

[Conventional technology]

Figure 4 shows an overview of the core structure of a boiling water reactor.

In the figure, the upper grid plate 4 and the core support plate 5 are internal support structures. The fuel support 3 fits into the upper end of the control rod guide tube 6 and is supported by the control rod guide tube 6 and the core support plate 5. As shown in FIG. 5, the fuel support 3 has a control rod insertion hole 7 having a cross-shaped cross section formed in the center thereof, and the control rod 2 is inserted through the control rod insertion hole 7 from the control guide tube 6 side. As shown in FIG. 6, the main components of this control rod 2 include a blade 8 having a cross-shaped cross section and a speed limiter 9 provided at the lower end of this blade 8. Mana, Blade 8
A handle 10 is provided at the upper end of the control rod 2 for lifting the control rod 2 when the control rod 2 is removed.

Reference numeral 11 denotes a control rod handling tool for hanging the control rod 2.

As shown in FIG. 4, four fuel assemblies 12 are placed on the fuel support 3 and fitted into the fuel insertion ports 13.

61st! ! Now, to show the configuration of the lower part of control rod 2,
Although the relationship with the fuel support 3 is not shown, when lifting it with the control rod handling tool 11, the fuel support 3 is placed on the speed limiter 9 at the bottom of the control rod 2 and lifted together as shown in FIG. It will be done.

In this way, since the control rod 2 is pulled up while being inserted into the fuel support 3, when changing to a new control rod, the control rod must be completely removed from the fuel support at some point.

An example of conventional control rod replacement work will be explained with reference to FIGS. 8 and 9.

In these figures, 14 is a conventional fuel support handling tool, 15 is a conventional control rod rack, 16 is a fuel support support section, 17 is a control rod storage section, 20 is a reactor core, 21 is a fuel exchanger, and 22 is a used control rod rack. 23 is a temporary fuel support stand, and 24 is a control rod drive mechanism.

To remove the control rod 2, the fuel support 3 was also lifted at the same time using the control rod handling tool 11 shown in FIGS. 6 and 7, and the control rod 2 and fuel support 3 were placed in the spent fuel pool 22 for storage. A fuel exchanger 21 is placed above the control rod rack 1.
to move the fuel support 3 to the fuel support support part 16.
Place it on.

Next, in order to store the control rod 2, it is transferred from the control handling tool 11 to a special handling tool, and the old control rod 2 is stored in the control rod storage section 17. Next is number 9! J! Using the fuel support handling tool 14 shown in i, the removed fuel support 3 is moved onto the new groove rod 2 previously stored in the other storage section 17 of the control rod rack 1.

Therefore, the new groove rod 2 is lifted up to a position where it can be handled by the control rod handling tool 11 using a special handling tool, and the new groove rod 2 is handed over to the control rod handling tool 11, lifted together with the fuel support 3, and moved to the reactor core 20 for installation. This is the procedure.

[Problem that the invention seeks to solve]

The reason why the procedure is complicated is that the control rods are inserted through the fuel support, and the control rod handling tool cannot penetrate the fuel support when it is stored in or removed from the control rod storage area. It is not possible to completely store the control rod in the control rod housing unless the control rod is pulled and nipped using a separate tool, and a handling tool is required to move the fuel support placed on the fuel support support onto the new groove rod. Replacement work is required.

As shown in FIG. 8, a procedure has been considered in which a temporary fuel support stand 23 is provided separately and the fuel support 3 and control n2 are handled separately, but this is time-consuming and there is no fuel support. It is not desirable to leave the control rods standing in the reactor core.

Regarding the handling tools used when replacing control rods and fuel supports, there is another example, Japanese Patent Publication No. 59-45958, but the focus is only on how smoothly they can pass through the upper grid plate. , no consideration was given to improving the efficiency of fuel support and control rod insertion/removal.

That is, conventionally, at least the control rod handling tool 1 shown in FIG.
The procedure was complicated as the fuel support handling tools shown in Figure 1 and Figure 5 had to be used several times.

As a result, the work took a long time and was inefficient.

An object of the present invention is to improve work efficiency by allowing control rods and fuel supports to be removed and installed together, and to store, take out, and store the control rods and fuel supports in a single lifting and lifting process, and to improve work efficiency. Another object of the present invention is to provide a control rod rack that does not require a temporary storage stand.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a fuel support supporting section that supports a fuel support and is movable onto at least two control rod storage sections, and a fuel support support section that supports a fuel support and that controls old control rods. Equipped with a control rod cradle that holds the old and new control rods so that they can be lifted and lowered when detached from the rod handling tool and stored in the control rod storage section, and when removing the new control rod from the storage section and lifting the control rod into the control rod handling tool. This paper proposes a new control rod rack.

[Effect]

In the present invention, it is possible to pull out the old control rod downward from the fuel support and move the fuel support support part on which the fuel support is placed onto the new control rod. Transfer IFl onto the control rod,
There is no need to suspend the work onto the new control rod. In addition, by installing a control rod cradle in the control rod storage section of the control rod rack that can raise and lower the control rods, it is easy to change the handling tool when transferring control rods from one control rod handling tool to another. This also improves work efficiency.

〔Example〕

Next, the present invention will be explained in detail with reference to FIGS. 1 to 3.

FIG. 1 is a perspective view showing one embodiment of a control rod rack according to the present invention. The control rod rack 1 includes a plurality of control rod storage sections 1.
7, a fuel support support part 16 located at the upper end thereof and receiving the fuel support 3 in a fitted state, and a fuel support support part 1
a drive mechanism 18 for rotationally moving the fuel support 3 on the control rod housing 17 onto the at least two control rod housings;
The control rod holder 19 is installed at the bottom of the control rod and moves up and down while the control rod is placed thereon, and its drive mechanism 27 is provided. In the figure, 2, 9.17, and 19.27 indicate the old control rods, 2A, 9A, and 17A.

Reference numerals 19A and 27A indicate the new control rods, and the drive mechanism 27 is omitted to avoid complexity.

This embodiment is different from the conventional example shown in FIG. This is because a control rod holder 19 is provided at the bottom for inserting and removing the control rod 2 or 2A into and from the fuel support 2 while being separated from the control rod handling tool 11 of FIG. 6 or 7.

The control rod rack 1 of the present invention is placed in a spent fuel pool 22, as shown in FIG. The old control rod 2 is suspended by a control rod handling tool 11 with a fuel support 3 attached to its lower end, and is carried to the control rod rack 1 by a refueling machine 21. Before storing the old control rod 2 in the control rod rack 1, the control rod cradle 19 is raised. When the old control rod 2 is inserted into the control rod storage part 17, the fuel support 3 moves into the fuel support support position. 16. Once the speed limiter 9 at the lower end of the control rod is placed on the control rod pedestal 19, remove the control rod handling tool 11.

The control rod pedestal 19 is lowered and the old control rod 2 is completely pulled out from the fuel support 3. Next, the fuel support support part 16 is rotated and the fuel support 3 is moved onto the new control rod 2A. Next, raise the control rod cradle 19A and install the new control rod 2A.
Insert into fuel support 3. From here on, the new control rod 2A and fuel support 3 are installed in the predetermined positions of the reactor core by following the procedure in reverse to that shown in FIG.

In this embodiment, the control rods 2 need only be hung and lifted once from the control rod rack, and the control rod handling tool 11 shown in FIG. 6 and the fuel support handling tool 14 shown in FIG. There is no need to replace it. The fuel support 3 can be moved from the old control rod to the disconnected control rod by one operation of the fuel support support part 16. These factors greatly improve the efficiency of control rod replacement work. Further, the temporary fuel support stand 23 that was necessary in the conventional example shown in FIG. 8 is no longer necessary together with the fuel support handling tool 14.

FIG. 2 shows another embodiment of the control rod rack according to the present invention. This embodiment differs from the embodiment in FIG. 1.

The point is that the fuel support support part is driven not in an arc but linearly by the rack 25 and the pinion 26. 1st
In the case of the illustrated example, unless a mechanism is provided to change the rotation length of the fuel support support part 6, the number of control rods that can be handled (the first
In the case of the figure, the number of fuel supports is limited to four (4), but in the case of the embodiment shown in FIG. 2, one fuel support supporting section can accommodate the number of rods accommodated in the control rod rack 1 as the limit. That is, in FIG. 2, the control rod rack 1 is extended forward and backward, and the control rod storage section 17 is
Even if it increases to 7A, 17B, 17G, etc.

It is possible to perform the work with one fuel support support section 16.

〔Effect of the invention〕

According to the present invention, the control rod and the fuel support can be removed and attached together, and the control rod and the fuel support can be stored, taken out, and stored in a single lifting operation, improving work efficiency. Further, special handling equipment such as a fuel support handling tool and a temporary fuel support stand is not required, which is also effective in terms of economy.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the control rod rack according to the present invention, FIG. 2 is a perspective view showing another embodiment, and FIG. 3 is a control rod replacement operation using the control rod rack according to the present invention. A diagram showing an example, FIG. 4 is a diagram showing the core structure of a boiling water reactor, and FIG. 5 is a diagram showing the fuel support and its handling tools.
Figure 6 is a diagram showing a control rod and its handling tool, Figure 7 is a diagram showing a fuel support, the control rod inserted therein, and its handling equipment, and Figure 8 is an example of conventional control rod replacement work. A diagram showing
FIG. 9 is a perspective view of a conventional control rod rack. 1... Control rod rack of the present invention, 2... Control rod, 3.
... Fuel support, 4... Upper grid plate, 5... Core support plate, 6... Control rod guide tube, 7... Control rod insertion hole, 8... Control rod blade, 9...・Speed limiter, 1
o...Control rod handle, 11...Control rod handling tool, 12.
... Fuel assembly, 13... Fuel insertion port, 14... Fuel support handling tool, 15... Conventional control rod rack, 1
6...Fuel support support part, 17...Control rod storage part, 18...Fuel support support part drive mechanism, 19...
Control rod pedestal, 20...core, 21...fuel exchange machine,
22... Spent fuel pool, 23... Temporary fuel support stand, 24... Control rod drive mechanism, 25... Rack, 26... Pinion, 27... Control rod pedestal drive mechanism.

Claims (1)

[Scope of Claims] 1. In a control rod rack equipped with a storage section for storing old and new control rods in order to replace the control rods that are inserted into the reactor core and used while being inserted into the fuel support, the old control rods are placed in the storage section. A fuel support support part is provided above the storage part to place and accommodate the fuel support and move it onto the new control rod when the fuel support is stored in the storage part, and to receive the control rod and move the upper end of the old control rod from the fuel support. A control rod rack characterized in that a control rod cradle is provided at the bottom of each of the storage sections for allowing the new control rod to escape while inserting the upper end of the new control rod into the fuel support that has been moved by the fuel support support section. 2. The control rod rack according to claim 1, wherein the fuel support support part is provided with a drive mechanism for rotationally moving itself on at least two of the storage parts. 3. The control rod rack according to claim 2, characterized in that the fuel support support part is provided with a drive mechanism for linearly moving itself on at least two of the storage parts.