JPH04128692A - Control rod guide tube - Google Patents

Abstract

PURPOSE:To improve dependability and reliability of loading and unloading of a control rod driving mechanism by providing a stopper mechanism for restriction of rotation and positioning to the connection part. CONSTITUTION:Projected stoppers 14c provided to a base 14a are positioned so that they engage grooves provided to outer tube claws 16c respectively, and the grooves on the upper end of an outer tube 16a contact the stoppers 14c of the base part to complete insertion operation. When a control rod driving mechanism 16 is rotated around its rear shaft, the side surfaces of the claws of the outer tube part of the control rod driving mechanism 16 contact the side surfaces of the projected stoppers 14c to restrict the rotation, complete positioning, and simultaneously complete connecting operation. When the stoppers 14c contact the groove parts of the outer tube parts of the control rod driving mechanism, the rotation is restricted, positioning is completed, a connection released state is simultaneously produced, the control rod driving mechanism 16 is lowered to enable removal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a fine motorized control rod drive mechanism (FMCRD).
The present invention relates to a nuclear reactor structure having a nuclear reactor structure, and particularly to a control rod guide tube suitable for connecting a control rod guide tube and an outer tube of a control rod drive mechanism.

[Conventional technology] Regarding the conventional fine movement electric control rod drive mechanism.

The structure of the connecting portion between the control rod drive mechanism and the control rod guide tube in the internal structure of the nuclear reactor will be explained with reference to FIGS. 6 to 10.

FIG. 6 is a schematic longitudinal cross-sectional view of a BWR type nuclear reactor pressure vessel.

In FIG. 6, a fine movement electric control rod drive mechanism 16 is installed in the lower part of the reactor pressure vessel 1.

Structures constituting the lower plenum include a control rod guide tube 14, a control rod drive mechanism housing 15, a neutron instrumentation guide tube 12, a neutron instrumentation housing 13, and the like. A control rod drive mechanism 16 is attached to the lower end of the control rod drive mechanism housing 15.

FIG. 7 is a partially detailed vertical sectional view showing the control rod guide tube 14 and the control rod drive mechanism 16. The control rod drive mechanism 16 includes a portion such as an outer tube 16a that is housed in the control rod drive mechanism housing 15, and a portion that is attached to the lower part of the control rod drive mechanism housing. here,
The outer tube 16a is connected to the control rod guide tube base 14a inside the control rod drive mechanism housing 15. Further, the hollow piston 16b is connected to the control rod 17.

FIG. 8 is a detailed longitudinal cross-sectional view of the connecting portion between the control rod guide tube base 14a and the outer tube, and the connecting portion between the hollow piston 16b and the control rod socket 17a.

FIG. 9(a) is a horizontal cross-sectional view of FIG. 8 showing the connecting portion between the control rod guide tube base 14a and the outer tube 16a and the connecting portion between the hollow piston 16b and the control rod socket 17a, and FIG. (b) is a horizontal sectional view of the connecting portion between the control rod guide tube base 14a and the outer tube 16a. The control rod guide tube base 14a, the outer tube 16a, the hollow piston 16b, and the control rod socket 17a each have claws at 45° intervals.

They are connected by this claw. Therefore, the connection between the control rod guide tube base 14a and the outer tube 16a and the connection between the control rod socket 17a and the hollow piston 16b can be established by rotating the control rod drive mechanism by 45 degrees around the axis, and the connected state and the uncoupled state can be achieved. becomes. Here, the connected state means that the base part pawl 14b, the outer tube part pawl 16c, the socket 17a pawl, and the hollow piston 16b pawl are in the same direction when viewed from a horizontal plane, that is, they overlap. The uncoupled state refers to a state in which they are shifted by 45 degrees when viewed in the angular direction, that is, a state in which they do not overlap. 6), and the control rod 17 is restrained from rotating around the shaft by the fuel assembly 5.

FIG. 10(a) shows the state when the control rod guide tube 14 and the outer tube 16a of the control rod drive mechanism 16 are inserted at the start of installation.

FIG. 10(b) shows a sectional view taken along the line ■-■ in FIG. 10(a). When inserting the outer tube 16a of the control rod drive mechanism 16 into the base 14a of the control rod guide tube 14, the outer tube catch 16c is inserted into the base claw 1.
4b, and can be inserted through the gaps.

FIG. 10(Q) shows a state in which the control rod guide tube 14 and the outer tube 16a of the control rod drive mechanism 16 are connected. Further, FIG. 10(d) is a cross-sectional view taken along the line ■-■ in FIG. 10(c). The control rod drive mechanism 16 inserted through FIGS. 10(a) and 10(b) is connected by rotating it by 45 degrees about the axis. Also, if you want to cancel the connection,
From the connected state shown in FIGS. 10(Q) and (d), rotating the #control rod drive mechanism 16 around its axis brings it into the uncoupled state, and lowering the control rod drive mechanism 16 allows it to be released. Can be removed.

That is, during normal operation of the reactor, the control rod guide tube 14
and the control rod drive mechanism 16 are the same outer tube 16a.
However, if you want to stop operation and pull out the control rods, remove the control rod guide tube 14 as described above.
The connection of the control rod drive mechanism 16 is released.

Regarding the internal structure of a nuclear reactor and the structure of a micro-movement electric control rod drive mechanism, for example, Hitachi Commentary VOL 66, No. 4 (April 1984) can be cited.

[Problems to be Solved by the Invention] The above conventional technology rotates the control rod drive mechanism by 45 degrees and does not have a stopper to mechanically control one rotation when the control rod drive mechanism is attached or detached. If the pawl on the outer tube of the control rod drive mechanism and the pawl on the control rod guide tube base overlap and interfere with each other in angular orientation when viewed in a horizontal plane, it was necessary to finely adjust the rotation of the control rod drive mechanism.

The purpose of the present invention is to solve the conventional problems as described above, and to improve the reliability of attaching and detaching the control rod drive mechanism, and to improve the reliability of the control rod drive mechanism and the positioning of the control rod. The guide tube is made to provide.

[Means for Solving the Problems] - The configuration of the control rod guide tube according to the present invention for solving the problems described above includes control rods and control rod drive mechanisms constituting a control rod device of a nuclear reactor, and a control rod drive mechanism for controlling these rods. In the control rod guide tube having a connecting part consisting of a rotary pawl connecting mechanism that connects the rod and the control rod drive mechanism, the connecting part is provided with a stopper mechanism for rotational positioning.

[Function] A protrusion is provided on the base of the reactor control rod guide tube that employs a micro-movement electric control rod drive mechanism, and a groove that engages with the protrusion is provided on the outer tube of the control rod drive mechanism to be connected to the base. Acts as a stopper.

This stopper can control the rotation of the control rod drive mechanism about its axis, set one position, and can also be detachably attached. therefore,
By setting this stopper, when the reactor operation is stopped,
In the event that a control rod is pulled out, the work of attaching and detaching the control rod guide tube from the control rod drive mechanism is always done reliably without any erroneous settings because the positioning can be done accurately.
Reliability and safety can be ensured.

[Example] An embodiment of the present invention is shown in FIGS. 1(a) and 1(b) below.

This will be explained using FIGS. 5(C) and 5(d) to FIGS. 5(a) and 5(b).

Figure 1 (a), (b), (c), (d)
FIG. 2 is an explanatory view of the operation of the connecting portion between the control rod guide tube with a stopper and the control rod drive mechanism outer tube of the present invention.

In Figure 1 (a), (b), (c), (d), 14
is the control rod guide tube, 14a is the guide tube base, 14b
14C is the claw of the same base.

stopper, 15, control rod drive mechanism housing, 1;
6a is a control rod drive mechanism outer tube, 16b is a hollow piston, and 16C is a pawl of the outer tube.

FIG. 1(a) is a track diagram showing the state before the outer tube lba of the control rod drive mechanism J6 is inserted into the control rod guide tube 14, and FIG. Diagram (a)
FIG. 2 is a horizontal sectional view taken along the line IT.

Here, when inserting the outer tube, control rod guide tube 1
4 is in a seated state with its lower end supported by the control rod drive mechanism house sink 15, and the upper part of the control rod guide tube 14 is supported in the horizontal direction by the core support plate 7 (FIG. 6). A bottle installed on the core support plate allows
Rotation around the axis is restricted.

In this state, the outer tube 1 of the control rod drive mechanism 16
6a into the base 14a of the control rod guide tube 14, the outer tube pawl 16c.

They are each located in the gap between the base pawls 14b and can be inserted through the gap. Further, the protruding stopper 14e provided on the base 14a is an outer tube pawl],
The insertion operation is completed when the groove at the upper end of the outer jaw 16a comes into contact with the base stopper 14c.

FIG. 1(e) shows a state in which the control rod guide tube 14 and the outer tube of the fWJ drive mechanism 16 are connected. In addition, FIG. 1(d) is similar to FIG. 1(r,
) is a horizontal sectional view taken along the line ■-■. Figure 1 (a), (b)
By then rotating the control rod drive mechanism 16 inserted as shown in FIG. When the side surface of the outer tube portion pawl 16c of the control rod drive mechanism 16 comes into contact with the side surface of the stopper 14e, rotation is suppressed, positioning is completed, and connection is completed at the same time. When connected, the base part pawl 14b and the outer tube part pawls 1, 60 are at the same angular position on the horizontal plane and overlap.

Also, if you want to cancel the connection, please refer to Figure 1 (C).

From the connected state of (d), control m Keyakillll! The base 14 of the control rod guide tube 14 is rotated around the axis (in the figure, the outer tube is rotated counterclockwise when viewed from below).
The protrusion-shaped stopper 14C provided at the outer tube pawl 16c of the control rod drive mechanism contacts the groove portion of the outer tube pawl 16c in a state where it is perfectly engaged and fits, the rotation is suppressed, the positioning is completed, and at the same time the connection is released, that is, Figure 1 (
The positional relationship b) is achieved, and by lowering the control rod drive mechanism 16, it can be removed.

As described above, according to the present embodiment, the stopper 14c provided on the base 14a has the effect of increasing the certainty of positioning and improving reliability when attaching and detaching the control rod drive mechanism 16, that is, connecting and disconnecting the control rod drive mechanism 16. There is.

FIG. 2 is a detailed diagram of the control rod guide tube with a stopper shown in FIG. 1. That is, the stone t<-1 with protrusions
4c is a view taken from below to make it easier to see the shape of the stopper pawl 14b of the control rod guide tube 14.

FIGS. 3(a), (b), (Q), and (d) show the control sequence for the stopper function of the control rod guide tube with a protruding stopper, which is an embodiment of the present invention shown in FIG. Base pawl 14b and stopper 14c of rod guide tube 14
, and is a diagram focusing on the outer tube portion pawl 16c.

FIG. 3(a) is a horizontal sectional view (II section in FIG. 1) of the base pawl 14b and stopper 14c of the control rod guide tube 14 when the control rod drive mechanism 16 is inserted from below. , which shows a developed view.

FIG. 3(b) shows a horizontal section (II section in FIG. 1) of the outer tube pawl 16c of the control rod drive mechanism 16 when the control rod drive mechanism 16 is inserted from below, and a developed view. This is what is shown.

FIG. 3(c) shows a state in which the control rod drive mechanism 16 is inserted from below and the outer tube pawl 16C is located between the stopper 14c of the base 14a and the base pawl 14b.

In this way, the outer tube part pawl 16c is inserted between the base part pawls 14b, and just meshes with the protruding stopper 14c provided on the base 14a and the groove provided on the outer tube part 16c.

FIG. 3(d) shows a state in which the base part pawl 14b and the outer tube part pawl 16c are connected.

By rotating the inserted control rod drive mechanism around the axis as shown in FIG. 3(c) (in the figure, rotating the outer tube clockwise when viewed from below), the base 1 of the control rod guide tube
When the outer tube portion pawl 16c of the control rod drive mechanism 16 comes into contact with the protruding stone (14c) provided on the rod 4a, one rotation is suppressed, the positioning is completed, and the connected state is established.

Here, the connected state refers to the base portion pawl 14b.

The outer tube portion pawls 16c are in the same angular position and overlap on the horizontal plane.

To release the connection, rotate the control rod drive mechanism 16 around its axis from the connected state shown in FIG. The stopper 14c in the shape of the outer tube 1
It comes into contact with the groove portion of 6c in a state where it just meshes and fits, and one rotation is suppressed and one positioning is completed, and at the same time, the connection is released, as shown in FIG. 3(C). The outer tube part pawl 16C is positioned between each of the base part pawls 14b, and can be removed by lowering the control rod drive mechanism 16 downward.

FIG. 4 shows a control rod guide tube having a protruding stopper, which is an embodiment of the present invention shown in FIG. base 1
4a, control rod drive mechanism housing 15, outer tube 16a, hollow piston 16b, control rod socket 17
It is a longitudinal cross-sectional view showing the arrangement of a. Also, Figure 5 shows
FIG. 5 is a horizontal sectional view taken along the ■-drink line and the IV-IV line in FIG. 4;

As shown in FIG. 5(a), the hollow piston 16b and the socket 17a also have pawls, and their connection method is the same as the connection method between the base part pawl 14b and the outer tube part pawl 16C. When viewed, the angular direction of the pawls of both connecting parts is the same.

Further, here, the control rod guide tube 14 is restrained from rotating about the axis by a bottle on the upper part of the core support plate, and the control rod is also restrained from rotating about the axis. Therefore, the stopper 14c of this embodiment includes the control rod socket 17.
This has the effect that positioning of the connection on the side a is also possible at the same time.

In addition, contrary to ``2'', it is also possible to provide a protrusion on the control rod drive mechanism outer tube side and provide a groove button on the control rod guide tube base.

[Effects of the Invention] According to the present invention, the rotation angle around the axis of the control rod drive mechanism can be positioned using the stopper provided at the base of the control rod guide tube, so that the attachment and detachment of the control rod drive mechanism is ensured. , which has the effect of improving reliability.

Moreover, there is an effect that attachment and detachment are possible at the same time as positioning the rotation angle.

Further, there is an effect that positioning and attachment/detachment of the control rod and the control rod drive mechanism can be performed at the same time.

Furthermore, this stopper mechanism can be easily manufactured by making simple design changes such as providing a protrusion on the base of the control rod guide tube and providing a groove that engages with the protrusion on the outer tube of the control rod drive mechanism. Because it is possible to
It can be said that it is extremely economical.

[Brief explanation of drawings]

FIG. 1(a) is a detailed diagram of a control rod guide tube with a stopper showing an embodiment of the present invention before connection with a control rod drive mechanism;
FIG. 1(b) is a horizontal sectional view taken along line I-X of FIG. 1(a),
FIG. 1(c) is a bird's-eye view of a control rod guide tube with a stopper after connection with a control rod drive mechanism, showing an embodiment of the present invention;
FIG. 1(d) is a horizontal sectional view of the ■-shore line in FIG. 1(c),
Figure 2 is a bird's eye view of a part of the stopper before connection with the control rod drive mechanism of the control rod guide tube with a stopper showing an embodiment of the present invention, and Figures 3(a) to 3(d) are diagrams of the present invention. FIG. 4 is a cross-sectional view and a developed view showing a sequence from before to after connection of a control rod guide tube with a stopper to a control rod drive mechanism, showing an embodiment of the invention; FIG. 4 shows an embodiment of the invention; FIG. 5 is a vertical cross-sectional view showing the connection between the control rod guide tube with a stopper, the control rod drive mechanism, and the control rod, and FIG. The figure is a vertical cross-sectional view showing a conventional internal pump type nuclear reactor.
FIG. 7 is a vertical cross-sectional view showing the connected state of the control rod, control rod drive mechanism, and control rod guide tube in the prior art;
The figure is in the prior art. FIG. 9 (a
) is a horizontal sectional view taken along the line ■-■ in Figure 8 and Figure 9 (b).
10(a) is a horizontal sectional view taken along the line VI-VIX. FIG. ■-■ of a)
The line horizontal sectional view, FIG. 10(c), is the bird track diagram after the control rod guide tube is connected to the control rod drive mechanism in the prior art.
Figure 0 (d) is the Lot! It is a horizontal sectional view taken along the line ■-■ of I(e). <Explanation of symbols> 1... Reactor pressure vessel, 2... Internal pump, 5... Fuel assembly, 7... Core support plate, 12...
- Neutron instrumentation guide tube, 13... Neutron instrumentation housing, ]4... Control rod guide tube, 14a... Base, 14
b...Base part pawl, 14c...Stopper, 15
...Control rod drive mechanism housing, 16...Control rod drive mechanism, 16a...Outer tube, 16b...
hollow piston. 16e...Outer tube part pawl, 17...Control rod. 17a...Control rod socket.

Claims (1)

[Scope of Claims] 1. A control rod having a connection part consisting of a control rod, a control rod drive mechanism, and a rotary pawl connection mechanism that connects these control rods and the control rod drive mechanism, which constitute a control rod device of a nuclear reactor. A control rod guide tube comprising a control rod guide tube, characterized in that the connecting portion is provided with a stopper mechanism for rotational positioning. 2. In the control rod guide tube according to claim 1, the stopper mechanism is provided with a protrusion on the control rod guide tube base, and a groove that fits into the protrusion on the outer tube of the control rod drive mechanism. A control rod guide tube characterized by: 3. The control rod guide tube according to claim 1, wherein the stopper mechanism is provided with a protrusion on the outer tube of the control rod drive mechanism, and a groove is provided on the control rod guide tube base. Rod guide tube.