JPH07229989A - Fitting device of control rod guide tube of high-temperature gas-cooled reactor - Google Patents

Abstract

PURPOSE:To make it possible to position a control rod guide tube correctly and to connect it to an upper neutron shielding body of a control rod column and thereby to make smooth insertion of a control rod possible. CONSTITUTION:In a fitting device of a control rod guide tube of a high- temperature gas-cooled reactor whereby the upper end part of the control rod guide tube 4 of the high-temperature gas-cooled reactor is supported by reactor vessel, while the lower end part of the control rod guide tube 4 is fitted in and fixed to an upper neutron shield 13 of a control rod column in the upper end part of a core 2 through the intermediary of a fit member, a guide pin 20 is provided in downward projection from the central part of the lower end face of the fit member 18, while a guide socket 21 into which the guide pin 20 is inserted is provided in the central part of a fit member supporting surface of the upper neutron shielding body 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control rod guide tube mounting device for highly accurately installing a control rod guide tube of a high temperature gas furnace on an upper portion of a core.

[0002]

2. Description of the Related Art In a high temperature gas reactor such as a high temperature engineering test reactor, a control rod guide tube for inserting a control rod for controlling a nuclear reaction is connected to the core of a reactor vessel containing high temperature gas. ing.

FIG. 4 shows a conventional example of such a structure, in which the control rod 1 is provided in the core 2 through a control rod guide tube 4 connecting the core 2 and the control rod drive device 3. It is adapted to be introduced into the control rod insertion hole 6 of the rod column graphite block 5. Then, the control rod 1 is vertically movably suspended in the core 2 by being hung from the drum 9 driven by the electric motor 8 via the wire rope 7 so as to control the fission reaction. There is.

One control rod 1 is housed in each of the two control rod guide tubes 4, and two wire ropes 7 are wound around one drum 9. Further, a shield 10 for shielding heat and radiation from the core 2 is provided below the control rod drive device 3. The control rod drive device 3, the shield 10 and the control rod guide tube 4 are connected by a frame 11 and integrated into one body. When loading the reactor, as shown in FIG. The control rod guide tube 4 is hung down and connected to the control rod column upper neutron shield 13 at its lower end.

By the way, conventionally, even if the control rod guide tube 4 and the control rod insertion hole 6 are slightly deviated from each other, the control rod column upper neutron shield 1 can be connected to each other.
3 and a fuel column upper neutron shield 14 arranged around it, a step portion 16 having a tapered surface 15 is provided, and a recess formed at the lower end portion of the control rod guide tube 4 by the step portion 16 Tapered portions 18a are provided on the periphery of the fitting member 18 that fits into the fitting member 17, and these tapered portions function as guides at the time of connection.

[0006]

However, in such a conventional control rod guide tube mounting device, a deviation occurs when the control rod column graphite blocks 5 are piled up, and as a result, as shown in FIG. When a gap 19 is formed between the control rod column upper neutron shield 13 and the fuel column upper neutron shield 14 which are stacked on the control rod column graphite block 5 of FIG. Not accurately positioned on the upper neutron shield 13,
There is a possibility that the control rod guide tube 4 and the control rod insertion hole 6 may be connected in a displaced state.

The present invention has been made in view of the above circumstances, and its purpose is to accurately position the control rod guide tube and connect it to the neutron shield above the control rod column to facilitate smooth insertion of the control rod. An object of the present invention is to provide a control rod guide tube mounting device for a high temperature gas furnace which can be performed.

[0008]

The present invention (Claim 1) includes:
In order to solve the above-mentioned problems, the upper end of a control rod guide tube of a high temperature gas furnace is supported by a furnace vessel, and the lower end of the control rod guide tube is attached to an upper part of a control rod column at an upper end of a core via a fitting member. In a control rod guide tube mounting device for a high temperature gas reactor fitted and fixed to a neutron shield, a guide pin is projected downward from a central portion of a lower end surface of the fitting member while fitting the upper neutron shield. A guide socket, into which the guide pin is inserted, is provided at the center of the member receiving surface.

Desirable configuration in the present invention (claim 2)
That is, the guide pin is formed with a taper portion whose diameter is gradually reduced from the base end side toward the tip end side, and the guide socket is formed with a tapered fitting hole for fitting with the taper portion of the guide pin. .

A further desirable configuration (claim 3)
Of the guide pin has a base end portion having a cylindrical shape with the same diameter over a certain length, the tapered portion is formed only on the tip end side of the guide pin, and the inlet portion of the fitting hole of the guide socket is the guide portion. That is, it is a cylindrical hole that matches the cylindrical base end of the pin.

[0011]

According to the present invention (Claim 1), at the time of assembly, the fitting member is guided by the tapered portion of the guide pin and the guide socket of the upper neutron shield and inserted into the upper neutron shield of the fuel column. As a result, even if a gap occurs between the adjacent control rod column upper shield and the fuel column upper neutron shield, centering is reliably performed, so that the control rod guide tube and the control rod column upper shield described above Accurate connection is possible.

Therefore, the reliability of the control rod guide tube connection is improved, and the control rod can be smoothly inserted into the core, so that the reliability of the power control of the high temperature gas reactor is improved.

Further, according to the desirable construction in which the tip of the guide pin and the fitting hole of the guide socket are tapered (claim 2), centering is further facilitated by both tapered portions.

Further, according to a desirable construction (claim 3) in which the base end portion of the guide pin and the inlet portion of the fitting hole are a cylinder and a cylindrical hole portion coinciding with the cylinder, respectively, the guide pin and the guide socket are more Securely connected.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In these figures, the same components as those of the conventional example will be described with the same reference numerals as those in FIGS. Further, since the whole structure is substantially the same as the conventional one, FIG. 4 is also used for the description of this embodiment.

In this embodiment, as shown in FIGS. 1 and 4, the control rod 1 is a control rod column graphite provided in the core 2 through a control rod guide tube 4 connecting the core 2 and the control rod drive device 3. It is adapted to be introduced into the control rod insertion hole 6 of the block 5. Then, the control rod 1 is vertically movably suspended in the core 2 by being hung from the drum 9 driven by the electric motor 8 via the wire rope 7 so as to control the fission reaction. There is.

One control rod 1 is housed in each of the two control rod guide tubes 4, and two wire ropes 7 are wound around one drum 9. Further, a shield 10 for shielding heat and radiation from the core 2 is provided below the control rod drive device 3. The control rod drive device 3, the shield 10 and the control rod guide tube 4 are connected by a frame 11 and integrated into one body. When loading the reactor, as shown in FIG. The control rod guide tube 4 is hung down and connected to the control rod column upper neutron shield 13 at its lower end.

Further, the control rod column upper neutron shield 13
And a fuel column upper neutron shield 14 arranged around it, a step portion 16 having a tapered surface 15 is provided, and a recess 17 formed by the step portion 16 is formed in the lower end portion of the control rod guide tube 4. A tapered portion 18a is also provided on the peripheral portion of the fitting member 18 to be fitted, and these tapered portions serve as guides for connection. As a result, the control rod guide tube 4
Even if the axes of the control rod insertion hole 6 and the control rod insertion hole 6 are slightly deviated from each other, they can be connected to each other.

In this embodiment, as shown in FIG.
Further, from the central portion of the lower end surface of the fitting member 18 to the guide pin 20
Is projected downward, and at the center of the upper surface, which is the fitting member receiving surface of the control rod column upper neutron shield 13,
A guide socket 21 into which the guide pin 20 is inserted is integrally formed and has a concave cross section.

The guide pin 20 is formed with a taper portion 22 having a diameter gradually decreasing from the base end side toward the tip (lower end) side, and the guide socket 21 is fitted with the taper portion 22 of the guide pin 20. A mating tapered fitting hole 23 is formed.

Therefore, when the control rod guide tube 4 is suspended from the upper portion of the reactor core 2 and connected to the control rod column upper neutron shield 13, the axis of the control rod guide tube 4 and the control rod column upper neutron shield are connected. The axis of the control rod insertion hole 6 provided in the control rod 13 may be deviated, but in the present embodiment, the tip of the guide pin 20 provided at the center of the lower surface of the fitting member 18 is the control rod. The guide pin 2 is inserted into the guide socket 21 provided at the center of the column upper neutron shield 13.
Since the side surface of 0 and the side wall of the guide socket 21 are in contact with each other, the axes of both sides are aligned with each other depending on their shapes.

Particularly, in this embodiment, since the guide pin 20 and the fitting hole 23 of the guide socket 21 are tapered, the guide pin 20 is slidably inserted into the guide socket 21, and the center of the fitting member 18 is inserted. And the center of the control rod column upper neutron shield 13 coincide with each other. Therefore, the axis of the control rod guide tube 4 and the axis of the control rod insertion hole 6 are smoothly and surely aligned with each other.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to (b). FIG. 3A is a view of the fitting member 18 as seen from below, and FIG. 3B is a longitudinal sectional view of a main part of FIG. 3A.

As shown in these figures, dowel pins 31 and dowel sockets 32 are provided around the lower portion of the fitting member 18 and the upper surface of the control rod column upper neutron shield 13 corresponding thereto. After the center of the fitting member 18 and the center of the control rod column upper neutron shield 13 coincide with each other, the fitting of the dowel pin 31 and the dowel socket 32 allows the fitting member 18 to be positioned in the rotational direction. It has become.

Under such a structure, the axis of the fitting member 18 and the axis of the control rod column upper neutron shield 13 are largely deviated by the guide pin 20 and the guide socket 21 of the one embodiment. In this case, when the edge of the inlet of the dowel socket 32 is lowered to the height of the top of the dowel pin 31, the axis of the guide pin 20 and the axis of the guide socket 21 may not be aligned with each other, and the misalignment may remain. At this time, the tip of the dowel pin 31 may collide with the edge of the inlet of the dowel socket 32, and the dowel pin 31 may not be further suspended.

Therefore, in this embodiment, as shown in FIG.
A cylindrical portion 24 having the same diameter is provided at the base end portion of the guide pin 20 as shown in FIG.
The cylindrical portion 2 having the same diameter is provided at the entrance of the fitting hole 23
5 is provided.

Thus, when the edge of the inlet of the dowel socket 32 reaches the same height as the top of the dowel pin 31, the axis of the fitting member 18 and the axis of the control rod column upper neutron shield 13 are already aligned with each other. And the allowable range of the gap 19 shown in FIG. 1 can be made larger.

[0028]

As described above, according to the present invention, the fitting member having the guide pin is attached to the tip of the control rod guide tube, and the guide socket is provided on the control rod column upper neutron shield. The control rod guide tube can be positioned with high accuracy and installed on the upper part of the core.

Therefore, the axes of the control rod guide tubes and the control rod insertion holes formed in the control rod column upper neutron shield can be accurately aligned with each other, facilitating the insertion of the control rods, and by extension, in the high temperature gas reactor. The reliability can be further improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of the present invention.

FIG. 2 is an operation explanatory view of the same embodiment.

FIG. 3A shows another embodiment of the present invention, in which the fitting member is seen from below, and FIG. 3B is a longitudinal sectional view of the relevant part.

FIG. 4 is an overall vertical cross-sectional view showing an installation situation of a control rod guide tube.

FIG. 5 is a diagram for explaining the operation of a conventional example.

FIG. 6 is a longitudinal sectional view of a main part showing a conventional example.

[Explanation of symbols]

 1 Control Rod Guide Tube 2 Core 13 Control Rod Column Upper Neutron Shield 14 Fuel Column Upper Neutron Shield 18 Fitting Member 20 Guide Pin 21 Guide Socket 22 Taper Part 23 Fitting Hole 24 Cylindrical Portion 25 Cylindrical Hole

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kenjiro Fukudo 2-4, Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Inside the Keihin office of Toshiba Corporation (72) Inventor Kazuhiro Matsuzaki 2-4, Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa Stock Company Toshiba Keihin Office

Claims (3)

[Claims] 1. A control rod column upper neutron shield for supporting the upper end of a control rod guide tube of a high temperature gas reactor in a furnace vessel, and a lower end of the control rod guide tube at an upper end of a core via a fitting member. In a device for mounting a control rod guide tube of a high temperature gas reactor, which is fitted and fixed to a guide member, a guide pin projects downward from a central portion of a lower end surface of the fitting member, and a fitting member receiving surface of the upper neutron shield. A control rod guide tube mounting device for a high temperature gas furnace, comprising a guide socket into which the guide pin is inserted at the center thereof. 2. The guide pin is formed with a taper portion whose diameter gradually decreases from the base end side toward the tip end side, and the guide socket has a tapered fitting hole for fitting with the taper portion of the guide pin. The control rod guide tube mounting device for a high temperature gas reactor according to claim 1, wherein the control rod guide tube mounting device is formed. 3. A base end portion of the guide pin has a cylindrical shape having the same diameter over a fixed length, and a taper portion is formed only on the tip end side of the guide pin, and the inlet of the fitting hole of the guide socket is formed. 3. The portion is a cylindrical hole portion that coincides with the cylindrical base end portion of the guide pin.
A control rod guide tube for the described high temperature gas furnace.