JP3512508B2 - Vacuum container for fusion device and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum container used for confining plasma in a nuclear fusion device, and more particularly to a structure of a port attachment portion where stress concentration is likely to occur.

[0002]

2. Description of the Related Art FIG. 10 is a perspective view showing an example of a vacuum container of a nuclear fusion device. The vacuum container 1 is for confining plasma in a vacuum and is formed in a donut shape as a whole. And to enhance the wall 2 of the vacuum chamber 1 is rigid, when it is necessary to thick to shield the nuclear products such as neutrons and γ-rays emitted by the nuclear fusion reactions of plasma, but the thick When the plasma is rapidly extinguished, the electromagnetic force acting on the container wall 2 by the electromagnetic induction action becomes large.

Therefore, as shown in FIG. 11, the container wall 2 is
The inner wall 3 and the outer wall 4 are constituted by a double wall reinforced with a poloidal rib 5, and a shield pebble 7 for shielding nucleation products is provided in a space formed by the inner wall 3, the outer wall 4 and the poloidal rib 5. A structure in which a large number of them are filled has been proposed (for example, Japanese Patent Laid-Open No. 06-249980). Further, as shown in FIG. 12, a port 6 is provided around the outer circumference of the vacuum container 1 for various purposes such as maintenance, plasma heating, exhaust and measurement.
Is provided in plural.

[0004]

[Problems that the Invention is to Solve In the vacuum chamber 1 configured in this manner, the plasma is not particularly strength problems in the case of normal plasma combustion operation, at the time of rapid extinction of the plasma flowing in the plasma Since the current IP is rapidly cut off, an eddy current IV is generated in the container wall 2 of the vacuum container 1 due to the electromagnetic induction action, and the interaction with the toroidal magnetic field BT and the poloidal magnetic field BP causes an electromagnetic field to appear on each part of the container wall 2. Force FP works. In the vacuum container 1 having a uniform shape without the port 6 as shown in FIG. 10, the eddy current IV and the electromagnetic force FP are uniform in the tridal direction, and stress concentration is unlikely to occur on the container wall 2 so that the vacuum container 1 is healthy. Sex is preserved.

However, when the port 6 is connected to the opening 9 of the container wall 2 as shown in FIG. 12 , the eddy current IVP bypasses the port 6 to cause a complicated electromagnetic force FP.
Therefore, a large stress is locally generated at the welded connection portion 10 between the container wall 2 and the port 6 due to bending or bending, and there is a risk that the soundness may be lost due to an unexpected situation such as vacuum breakage.

Further, in the method of transporting or assembling on-site in a state where the shield pebble 7 is filled in the double wall, the total weight of the vacuum container 1 becomes large, the transport limit is exceeded, and handling during assembly is difficult. Since there is a problem such as the above, the shield pebble 7 is filled with the vacuum container 1 after the vacuum container 1 is assembled in the field. The filling method is, for example, transfer of the shield pebbles 7 together with water by pipes connected to the upper and lower sides of the vacuum container 1,
Although it is filled, there is a problem that the shielding performance is deteriorated because the passage around the port 6 is bypassed and the filling is not uniform.

The present invention has been made in order to solve the above-mentioned problems, and improves the structural soundness and shielding performance around the port mounting portion of the vacuum container and is a highly reliable vacuum container for a nuclear fusion device. The purpose is to provide.

[0008]

In order to achieve the above object, the invention according to claim 1 is such that a container wall forming a vacuum container is a double wall in which an inner wall and an outer wall are reinforced with a poloidal rib. In a vacuum container of a nuclear fusion device having a port connected to an opening provided in the container wall, the container wall includes an inner wall and an outer wall of a port seat corresponding to an inner wall and an outer wall of the container wall. Forming part of
In addition, the port seat opening wall is joined to the opening side of the port seat inner wall and the port seat outer wall, and the members are integrally joined with the reinforcing member to connect the port mounting seat to the container wall, and the port of the port seat opening wall. It is characterized in that the connecting portion is provided at a position projecting from the outer wall of the port seat.

According to a second aspect of the present invention, in the vacuum container of the nuclear fusion device according to the first aspect, the inner wall of the port seat, the outer wall of the port seat, the opening wall of the port seat, and the reinforcing member are diffusion-bonded. It is characterized by being joined and integrated.

In the invention corresponding to claim 3, the reinforcing material according to claim 2 is composed of a plurality of pipes, and the pipe has a cross-sectional shape of a triangle, a quadrangle, a hexagon or a combination of these pipes. It is characterized by being composed of either pipe.

The invention corresponding to claim 4 is the method for manufacturing a vacuum container for a nuclear fusion device according to claim 2, wherein an outer wall of the port seat, an inner wall of the port seat, an opening wall of the port seat, and a reinforcing material are included. Before joining and integrating these members into the space formed by, the step of filling the shield pebbles, the step of joining and integrating the members by diffusion joining, and the joining and attaching the port mounting seat to the container wall Process,
And filling the space between the inner wall and the outer wall of the container wall with the shield pebble.

[0012]

According to the inventions corresponding to claim 1, claim 2 and claim 3, the port mounting seat, in which a large stress is generated by the electromagnetic force acting at the time of rapid plasma extinction, is integrally joined by diffusion bonding including the reinforcing material. And the welding connection between the port mounting seat and the container wall of the vacuum container is provided in the area with a small electromagnetic force away from the port, and the port connection part of the port seat opening wall that constitutes the port mounting seat is the port. Since the position is projected from the outer wall of the seat, the stress concentration due to the stepped structure or the like can be avoided from the welded portion, and the structural soundness is significantly improved.

According to the invention corresponding to claim 4,
Since the space of the port mounting seat is filled with the shield pebble in advance, the port mounting seat is welded to the vacuum container,
Since the filling can be performed more reliably than when filling locally, the shielding performance is improved.

[0014]

Embodiments of the vacuum container of the nuclear fusion device according to the present invention will be described below with reference to the drawings. A first embodiment (corresponding to claim 1, claim 2 and claim 3) will be described first with reference to FIGS. 1 to 3. 1 is a perspective view showing the installation relationship of the port mounting seat 11 with respect to the container wall 2 of the vacuum container 1, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a line BB of FIG. Cross-sectional views along each are shown. The port mounting seat 11 includes a port seat inner wall 12 and a port seat outer wall 13 that correspond to the inner wall 3 and the outer wall 4 of the container wall 2.
And the opening 9 of the port seat inner wall 12 and the port seat outer wall 13
The port seat opening wall 14 joined to the side and the reinforcing member 15 for connecting and reinforcing these members are joined and integrated.

The port mounting seat 11 integrated with this joint
The inner wall 12 of the port seat to the inner wall 3 of the container wall 2 and the outer wall of the port seat
13 are welded to the outer wall 4 respectively, and the port connecting portion 14a of the port seat opening wall 14 is further projected than the port seat outer wall 13.
The vacuum container 1 is constructed by welding and connecting the port 6 to.

Although the reinforcing material 15 of the port mounting seat 11 is shown in FIG. 3 as a honeycomb shape, it may be a triangular shape or a quadrangular shape as shown in FIG. 4 or 5.
Although not shown, a general rib structure can be used. Further, the reinforcing member 15 is orthogonal to the wall surface of the port seat opening wall 14,
Either parallel arrangement may be used, and it is determined by the load direction.

FIGS. 6 to 8 show a part of the port mounting seat 11 and show a structure and a manufacturing method for integrating the port mounting seat 11 by diffusion bonding. Hereinafter, a method of joining and integrating by HIP (hot isotropic pressure), which is one method of diffusion joining, will be described. A sealing plate 16 is welded to one end of the reinforcing material 15 of the hexagonal tube or the half-divided tube of the hexagonal tube, and the reinforcing materials 15 of the above shape are arranged in a honeycomb shape so as to be in close contact with each other. Each end face is sealed with a seal weld 18. After that, the reinforcing material 15 temporarily joined in a honeycomb shape by the seal welding 18, the port seat inner wall 12, the port seat outer wall 13, and the port seat opening wall 14 are assembled, and the members are sealed by the seal weld 18.

In the case of HIP joining, it is necessary to keep the joining portion between the respective members in a vacuum. However, after the seal welding, a method of evacuating and sealing a part of the seal and a vacuum chamber like the EB welding are used. Although there is a method of sealing by performing the seal welding 18 inside, any method may be used.

After that, high-temperature, high-pressure HIP treatment is performed, so that the respective members of the port seat inner wall 12, the port seat outer wall 13, the port seat opening wall 14 and the reinforcing member 15 are diffusion-connected and firmly integrated.

Next, the function and effect of the first embodiment constructed as above will be described. Since the above-mentioned members constituting the port mounting seat 11 are integrally joined by diffusion bonding and have no welded portion, the structural soundness of the port mounting seat 11 in which a large stress is generated is improved.

Further, since the welded connection portion 10 between the container wall 2 and the port mounting seat 11 is arranged at a portion apart from the port 6 where the stress due to electromagnetic force is low, it is also affected by the complicated electromagnetic force acting on the port 6. Instead, it has sufficient strength as a part of the container wall 2.

Further, since the port 6 is welded to the port connecting portion of the port seat opening wall 14 of the port mounting seat 11, stress concentration due to a step structure or the like can be avoided and heat applied to the container wall 2 at the time of welding. The influence can be suppressed.

FIG. 9 is a sectional view of a port mounting seat 11 showing a second embodiment (corresponding to claim 4) of the present invention. Before joining and integrating the inside of the polygonal tube forming the reinforcing member 11, It is filled with the shield pebbles 7, and on the opposite side of the port seat opening wall 14, a fall prevention plate 17 having air permeability such as a wire net for preventing the shield pebbles 7 from falling is fixed. Other configurations and HIP
The manufacturing method by joining by processing and integration is the same as in the first embodiment.

Next, the function and effect of the second embodiment will be described. After the port mounting seat 11 is connected to the container wall 2 and the vacuum container 1 is assembled in the field, the shield pebble 7 is placed in the space such as the reinforcement material 15.
Is difficult to fill, and if possible, uniform filling is difficult and large voids may form. According to the present invention, however, the space is filled with the shield pebbles 7 in advance, so that the shield pebbles 7 are evenly filled and the shielding performance can be prevented from being deteriorated.

[0025]

As described above, according to the present invention, the structural soundness and the shielding performance around the port mounting portion of the vacuum container in which a complicated electromagnetic force works is remarkably improved, and a highly reliable fusion device is provided. A vacuum container can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing a port mounting seat portion of a first embodiment of a vacuum container of a nuclear fusion device according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3 is a sectional view taken along the line BB of FIG.

FIG. 4 is a sectional view showing another embodiment of the reinforcing material of the first embodiment of the present invention.

FIG. 5 is a sectional view showing another embodiment of the reinforcing material of the first embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of a port mounting seat according to the first embodiment of the present invention.

7 is a sectional view taken along the line CC of FIG.

8 is a cross-sectional view taken along the line DD of FIG.

FIG. 9 is a sectional view of a port mounting seat according to a second embodiment of the present invention.

FIG. 10 is a partial perspective view showing the overall concept of the vacuum container of the nuclear fusion device.

11 is a cross-sectional view taken along the line EE of FIG.

FIG. 12 is an explanatory diagram of electromagnetic force and the like that act on the vacuum container and the port.

[Explanation of symbols]

1 ... Vacuum container 2 ... Container wall 3 ... inner wall 4 ... outer wall 5 ... Poloidal rib 6 ... Port 7 ... Shield Pebble 9 ... Opening 10… Weld connection 11… Port mounting seat 12 ... Port seat inner wall 13 ... Port seat outer wall 14 ... Port seat opening wall 14a ... Port connection part 15 ... Reinforcement material 16 ... Seal plate 17… Fall prevention plate 18… Seal welding

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-249980 (JP, A) JP-A-6-59062 (JP, A) JP-A-5-11079 (JP, A) JP-A-59- 85988 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G21B 1/00

Claims (4)

(57) [Claims] 1. A vacuum container for enclosing a plasma, comprising:
The container wall forming this vacuum container is composed of a double wall reinforced with a poloidal rib between the inner wall and the outer wall, and in the vacuum container of the nuclear fusion device equipped with a port connected to the opening provided in this container wall. A part of the container wall is formed by the inner wall and the outer wall of the port seat corresponding to the inner wall and the outer wall of the container wall, and the port seat opening wall is formed on the opening side of the inner wall of the port seat and the outer wall of the port seat. It is characterized in that a port mounting seat that abuts and joins and integrates these members with each other is connected to the container wall, and that the port connecting portion of the port seat opening wall is provided at a position projecting from the outer wall of the port seat. A vacuum container for a nuclear fusion device. 2. The vacuum container for a nuclear fusion device according to claim 1, wherein an inner wall of the port seat, an outer wall of the port seat, an opening wall of the port seat, and a reinforcing member which constitute the port mounting seat are integrally joined by diffusion bonding. . 3. The reinforcing material forming the port mounting seat is composed of a plurality of pipes, and the pipe has a cross-sectional shape of a triangle, a quadrangle, a hexagon or a combination of these pipes. The vacuum container of the nuclear fusion device according to claim 2, characterized in that. 4. A shield pebble is filled in a space formed by an outer wall of the port seat, an inner wall of the port seat, an opening wall of the port seat, and a reinforcing member which constitute the port mounting seat before the members are joined and integrated. A step of integrally joining the members by diffusion joining, a step of connecting the integrally joined port mounting seat to the container wall, and a step of filling a shield pebble between the inner wall and the outer wall of the container wall. 3. The method for manufacturing a vacuum container of a nuclear fusion device according to claim 2.