JPH0750184B2 - Reactor control rod drive - Google Patents

Description

The present invention relates to a reactor control rod drive system.

[Conventional technology]

2 and 3 show a conventional example of a control rod driving device for a liquid metal sodium cooled reactor. As shown in the figure, the reactor control rod drive device 1 includes a drive unit 2
Can be roughly divided into the upper guide tube section 3.

The upper guide tube portion 3 is supported at the upper surface position of the rotary plug 4, is installed in the reactor vessel in the atmosphere of the reactor cover gas 5 (argon, sodium paper, etc.) and sodium 6, and the lower end thereof is a gripper. It is connected to the control rod 8 via 7. The control rod 8 is housed in a control rod guide tube 9.

The drive unit 2 is housed in a control rod drive mechanism drive unit guide cylinder (core upper mechanism) 10 located on the rotary plug 4, and the lower end thereof is connected to the uppermost portion of the upper guide pipe unit 3. .

The drive unit 2 and the upper guide tube unit 3 can be separated and maintained separately during a regular inspection of the reactor. In addition, the seal of the reactor cover gas 5 when the control rod 8 moves up and down (withdrawal and insertion) is performed by the stroke bellows (welded bellows) 12 attached to the lower end of the upper guide tube 11 of the upper guide tube section 3. To do.
By the way, the upper guide tube 11 and the guide tube 13 of the upper guide tube part 3 are connected by a connecting means for detachably connecting them and a bolt 14 arranged in the axial direction (longitudinal direction). Therefore, in order to prevent the cover gas 5 inside the reactor from leaking out of the reactor vessel through the gap between the bolt 14 and the play hole, a sealing part such as an O-ring 15 is provided at the connecting portion between the upper guide pipe 11 and the guide pipe 13. It was necessary. Also, an O-ring seal check gas system 16 for periodically checking the soundness of the O-ring 15 is required.

[Problems to be solved by the invention]

 The above conventional technique has the following problems.

If the O-ring sealing performance at the connection between the upper guide tube and the guide tube deteriorates and it is necessary to replace it with a new one during operation of the reactor, remove the drive section and then remove the upper guide tube section. The whole thing had to be taken out of the reactor vessel, washed to remove sodium etc. and decomposed. However, this replacement work is extremely difficult in reality, and is practically impossible.

The present invention has been made in view of the above points, and an object of the present invention is to provide a reactor control rod drive device capable of significantly improving maintainability.

[Means for solving problems]

The above object is achieved by forming the connecting means with a pin which is driven perpendicularly to the axial joint surface between the upper guide tube and the guide tube.

[Action]

Since the connecting means is formed by the pin driven in at a right angle to the axial joint surface between the upper guide pipe and the guide pipe, the bolts will not be formed if the upper guide pipe and the guide pipe are arranged in the axial direction as in the conventional case. It becomes unnecessary, and the hole which penetrates the upper guide tube in the axial direction is unnecessary. Therefore, the reactor cover gas that rises in the gap between the upper guide tubes is sealed by the O-ring installed on the outer circumference of the upper guide tubes and does not leak out of the reactor vessel. As described above, a sealing part such as an O-ring at the connecting portion between the upper guide pipe and the guide pipe becomes unnecessary, and an O-ring seal check gas system for regularly checking the soundness of the O-ring at this connecting portion is also unnecessary. .

[Examples] Hereinafter, the present invention will be described based on illustrated examples. FIG. 1 shows an embodiment of the present invention. The same parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted.
In this embodiment, the connecting means is formed by a pin 17 driven in a direction perpendicular to the axial joint surface between the upper guide tube 11 and the guide tube 13. This eliminates the need for the axially arranged bolts for connecting the upper guide tube and the guide tube as in the conventional case, and the sealing parts such as O-rings at the connecting portion between the upper guide tube and the guide tube are not required. A reactor control rod drive device that is unnecessary and can greatly improve maintainability can be obtained.

That is, the upper guide tube 11 and the guide tube 13 were connected to each other at the position of the centering stud portion at the time of connection and by driving the pin 17 in the direction perpendicular to the axis. In this case, the hole for the pin 17 is
Does not penetrate By doing so, the reactor cover gas that rises in the gap between the upper guide pipe 11 and the guide pipe 13 is prevented from flowing into the outer periphery of the upper guide pipe 11 and the guide pipe 13 and the O-ring seal check gas. O-rings installed to seal the gas of the gas system 16, the gas of the stroke bellows back pressure system, etc. are prevented from leaking out of the reactor vessel. Therefore, as described above, the O of the connection between the upper guide pipe 11 and the guide pipe 13 is very difficult to maintain.
Sealing parts such as rings are not required, and the maintainability of the reactor control rod drive device can be greatly improved. In addition, the O of the connecting portion between the upper guide pipe 11 and the guide pipe 13 is
Since no seal parts such as rings are needed, the soundness of the O-ring seal at this connection is checked regularly.
The ring seal check gas system is also unnecessary, and the gas system for the reactor control rod drive can be simplified.

〔The invention's effect〕

As described above, according to the present invention, the maintainability of the reactor control rod drive device is greatly improved, and the reactor control rod drive device capable of greatly improving the maintainability can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view around an upper guide pipe and a connecting portion between the guide pipes of an embodiment of a reactor control rod driving device of the present invention, and FIG. 2 is a vertical side view of a conventional reactor control rod driving device. FIG. 3 is a vertical sectional side view around the connection between the conventional upper guide tube and the guide tube. 2 ... Drive part, 3 ... Upper guide tube part, 11 ... Upper guide tube, 13 ... Guide tube, 17 ... Pin.

Claims (1)

[Claims] 1. A drive part, and an upper guide pipe part which is detachably connected to the drive part and which is located inside the reactor vessel. The upper guide pipe part has an upper guide pipe and a guide pipe. Then
In the reactor control rod drive device, wherein the upper guide pipe and the guide pipe are connected with a connecting means for detachably connecting them, in the reactor control rod drive device, the connecting means is arranged in the axial direction of the upper guide pipe and the guide pipe. Reactor control rod drive device, characterized in that it is formed with pins that are driven in the direction perpendicular to the joint surface of.