JP2002139589A - Vacuum vessel for nuclear fusion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the assembling work of a vacuum vessel and reduce the cost. SOLUTION: A bolt 11 is screwed into a bolt seat 6 welded to an inner wall 4, and a plurality of shielding plates 12 are inserted and stacked to the bolt 11 via spacers 14. The bolt 11 is inserted into the bolt hole 3 of an outer wall 1 to fit the outer wall 1, a nut 17 is screwed to a bolt head section and fastened and fixed via a cap block 16. The bolt 11 is welded and fixed to the bolt hole 3 of the outer wall 1. Since the bolt 11 has the function of a rib, the number of ribs is reduced, and the weld line length can be shortened, thereby the assembling work is simplified, and the cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum vessel for a nuclear fusion apparatus, which can simplify the operation of assembling sectors and reduce costs.

[0002]

2. Description of the Related Art A nuclear fusion device generates a nuclear fusion reaction using deuterium or the like as a fuel. In a fusion device,
Hydrogen is supplied into a donut-shaped vacuum vessel, and a voltage is applied to the plasma to excite the plasma to heat the hydrogen to an extremely high temperature, thereby causing a nuclear reaction (nuclear fusion reaction) in which hydrogen nuclei fuse together. It wakes up.

FIG. 8 is a configuration diagram showing a sector of a vacuum vessel used in a conventional nuclear fusion device. This vacuum vessel is formed by joining a plurality of sectors 80 in an annular shape. Each sector 80 has an inner wall 81, a plurality of ribs 82 provided on the outer surface of the inner wall 81, and an outer wall 83 joined to the rib 82. It is composed of The inner wall 81 and the outer wall 83 are formed by welding a plurality of plate members in a ring shape, and the inner wall 81 and the outer wall 83 and the rib 82 are welded. Also, the rib 82
Are provided at right angles to the circumferential direction of the sector 80 and the ring ring direction.

Further, an inner wall 81, an outer wall 83 and a rib 82
A shielding plate 85 for shielding radiation is built in a stacked state in a space 84 made of. The shielding plate 85 is made of high manganese steel or stainless steel to which boron having a neutron absorbing ability is added. As shown in a partial cross-sectional view of FIG.
A bolt seat 86 is provided on the outer surface of the inner wall 83 between the two, a bolt 87 is set on the bolt seat 86, a shielding plate 85 is sequentially inserted into the bolt 87, and a bolt end protruding from the outer wall 81 is welded and fixed. Further, the sector 80 is provided with a port 88 for evacuation and a port 89 for introducing hydrogen.

[0005]

However, in the above-described conventional vacuum vessel, the rib 82 is provided on the inner wall 81 and the outer wall 83.
, There is a problem that the welding work inside becomes difficult and costs increase. For example, in the case of a sector having a maximum diameter of 15 m and a width of about 4 m, the number of the ribs 82 is 60 to 70, so that the welding workability greatly affects the assembling work. On the other hand, the rib 82 and the outer wall 8
If all three are to be welded, the outer wall 83 is required for each rib area, so that the outer wall 81 of the sector 80 has a patchwork shape and the surface is not uniform. further,
If there are many welded parts, the heat effect on members such as the outer wall 81 will be large, and thus heat treatment may be required from the viewpoint of soundness, and the assembling work is troublesome.

Accordingly, the present invention has been made in view of the above, and an object of the present invention is to provide a vacuum container which can simplify the vacuum container assembling operation and reduce the cost.

[0007]

According to a first aspect of the present invention, there is provided a vacuum vessel for a fusion device, wherein a plurality of annular sectors are connected.
The sector has a structure in which a plurality of ribs are provided between an inner wall and an outer wall, and further has a structure in which bolts are passed between the inner wall and the outer wall to fix the inner wall and the outer wall, and a plurality of blocks for shielding radiation. Are laminated and fixed by the bolts.

According to a second aspect of the present invention, there is provided a vacuum vessel for a nuclear fusion device, wherein a plurality of annular sectors are connected to each other, wherein a rib is provided on the inner wall of the sector and the inner wall faces the inner surface of the outer wall. Bolts are erected on the inner side of the, and the shielding plate for shielding radiation is laminated and fixed by the bolts, and the outer wall is attached to the bolt holes of the outer wall through the bolts, and the bolt hole periphery and the bolts are fixed from the outer surface of the outer wall. Things.

According to the present invention, the bolt passed between the inner wall and the outer wall functions as a rib for maintaining the strength of the sector.
As a result, the number of ribs used for the sector is reduced, and the entire welding line length is correspondingly reduced.

According to a third aspect of the present invention, there is provided a vacuum vessel for a nuclear fusion device, wherein the bolt is further provided to be inclined from a direction perpendicular to an inner wall surface and an outer wall surface. . Further, the vacuum container of the nuclear fusion device according to claim 4 is, in the vacuum container of the nuclear fusion device, further provided such that the rib is inclined between an inner wall and an outer wall,
A shielding plate for shielding radiation is obliquely laminated along the ribs. By providing the bolts or ribs at an angle, even if radiation is emitted from the inside of the vacuum vessel in a direction substantially perpendicular to the inner wall, the radiation is shielded by the shielding plate. Leakage can be made very small. By arranging both the bolt and the rib obliquely, it is possible to further prevent the radiation from leaking.

According to a fifth aspect of the present invention, there is provided a vacuum vessel for a nuclear fusion device, wherein a plurality of annular sectors are connected to each other, wherein the sector has a plurality of ribs inclined between an inner wall and an outer wall. This is a structure in which shielding plates for shielding radiation are obliquely stacked along the ribs.

As described above, even if radiation is emitted from a direction substantially perpendicular to the inner wall, the radiation can be shielded by the shielding plate by arranging the ribs at an angle. For this reason, leakage of radiation can be extremely reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment. It goes without saying that the components of the present invention include those whose design can be changed by those skilled in the art.

[First Embodiment] FIG. 1 is a plan view showing an outer wall of a sector of a vacuum vessel according to a first embodiment of the present invention. FIGS. Each outer wall is shown. The outer walls 1a and 1b of the sector have a configuration in which plate-shaped outer skins 2 are connected in the ring direction.
The outer walls 1a and 1b are provided with a plurality of bolt holes 3 on a line (indicated by a dashed line) where the rib passes in the ring direction in the conventional sector. The number of the bolt holes 3 can be arbitrarily determined, but is preferably determined based on the strength required for the vacuum vessel. The bolt holes 3 are located slightly differently for the outer walls 1a and 1b having different port shapes as shown in FIGS.

FIG. 2 is a plan view showing an inner wall of a sector of the vacuum vessel of the present invention. FIGS. 2A and 2B show inner walls 4a and 4b of adjacent sectors. Like the outer walls 1a and 1b, the inner walls 4a and 4b of the sector are formed by connecting plate-like inner skins 5 in the ring direction, and the bolts are formed on the line (indicated by a chain line) in the conventional sector where the ribs pass in the ring direction. This is a configuration in which a plurality of seats 6 are provided. Bolt seat 6
Is joined to the outer surface of the inner wall by TIG welding or MIG welding. The bolt seat 6 is used for the inner wall 4.
This is to prevent a penetrating portion from being formed in a and 4b.

Further, ribs 7 are welded to both sides and the center of the inner walls 4a and 4b in a ring direction. Further, a plurality of ribs 8 are welded in the circumferential direction of the inner walls 4a, 4b. When the outer walls 1a and 1b are attached, the ribs 7 and 8 are welded to the inner surfaces of the outer walls. In other words, in this sector, two ribs (corresponding to a portion shown by a chain line) are omitted from the plurality of ribs 7 provided in the conventional ring direction. The inner walls 4a and 4b, the outer wall 1a,
For the 1b and the ribs 7 and 8, a superalloy containing nickel or cobalt as a main component, a stainless steel material, carbon steel, or the like can be used.

FIG. 3 is an assembly view of the sector shown in FIG. 1 and FIG. FIG. 4 is a partial cross-sectional view when a sector is assembled. In this sector 50, the inner walls 4a, 4b
Is formed in an annular shape by connecting the inner skin 5, and ribs 7 are welded to both sides and the center in the annular direction. Further, a port short pipe 10 is welded to the port hole 9 and joined to the center rib 7. Bolts 11 are screwed into the bolt seats 6 of the inner walls 4a and 4b, respectively. A screw groove 15 is formed in the head of the bolt 11. The bolt 11 is fastened by fitting a fastener into the threaded groove 15 and rotating the fastener. Further, since the bolt 11 is used in place of a conventional rib, the diameter of the bolt 11 must be sufficient not only for fixing the shielding plate but also for maintaining the strength of the sector.

Specifically, in the sector 50, the maximum outer diameter is 10m, the maximum width is 4m, and stainless steel is used as a material constituting the sector 50. The thickness of the inner wall 4, the outer wall 1, and the ribs 7 and 8 is Is 10 mm, and the annularly formed rib 7
35, the number of circumferential ribs 8 is 12, and the shielding plate 1
2 is made of boron-containing stainless steel and its thickness is 17m
When m is set, 44 bolts 11 having a diameter of approximately 34 mm are preferably dispersed and arranged on the rib wire. This makes it possible to obtain the same strength as the rib.

In the section formed by the ribs 7 and 8 and the port short pipe 10, a shielding plate 12 made of high manganese steel or stainless steel having the section shape is fitted (only a part is shown in the figure). In order to improve the neutron shielding ability, it is preferable to use a stainless steel alloy containing boron or high manganese steel for the shielding plate. In particular, when shielding gamma rays and neutron rays, it is preferable to use a stainless steel alloy containing boron. The shielding plate 12 is provided with a plurality of bolt holes 13 through which the bolts 11 pass. The bolt holes 13 position and fix the shielding plate 12 to the inner walls 4a and 4b. Also, a plurality of shielding plates 12 are provided by lamination (only two are shown in the figure), and a spacer 14 is provided between each shielding plate 12. The space between the shielding plates 12 formed by the spacers 14 is filled with water, nitrogen, or the like. Filling with water makes it possible to simultaneously slow down the neutrons and cool the vacuum vessel.

Next, after a plurality of shielding plates 12 are stacked,
Attach outer skin 2 from outside. To fix the outer skin 2, the bolt 11 is passed through the bolt hole 3, and is fixed with a nut 17 via a holding block 16. The pressing block 16 tightens the peripheral edge of the bolt hole 3 on the outer wall, the spacer 14, and the shielding plate 12, thereby being firmly fixed. Also, the spacer 1
4 and a part of the shielding plate 12 function to reinforce the ribs.

The outer wall 1 is formed by attaching a plurality of outer skins 2 and welding them to each other. The bolt hole 3 of the outer wall 1 has a tapered cross section, and a bottom peripheral edge 3a of the bolt hole 3 abuts a step 11a formed on the bolt 11.
Further, the space between the bolt hole 3 and the bolt 11 is joined by TIG welding and arc welding (beat 18). According to this configuration, since the welded portion becomes spot-like, the sector 5
0 The welding line length can be shortened as a whole. In addition, the inner wall 4a,
A stud bolt may be used in place of the type in which the bolt 11 is screwed into the bolt seat 6 provided in 4b. By joining a plurality of the sectors 50 assembled as described above, a donut-shaped vacuum container is formed. Each sector 50
The two are joined by welding.

As described above, according to this vacuum vessel, since the bolt conventionally used for mounting the shielding plate 12 is employed as a reinforcing structure instead of the rib, the entire welding line length can be shortened. Specifically, the number of ribs, which has been about 70 in the past, can be reduced by about 2/3, so that the weld line length is shortened accordingly. For this reason, welding work is simplified and manufacturing costs can be reduced. In addition, since the number of welded portions is reduced, the influence of heat due to welding can be suppressed. Further, since bolts conventionally used for fixing the shielding plate 12 can be omitted, the number of parts can be reduced.

FIG. 5 is a plan view showing a modification of the sector. In FIG. 1, only the outer wall 1 is shown, and the corresponding inner wall 4 is not shown. In the above-described sector 50, the ribs corresponding to the two ribs are replaced with bolts, but the inside of the sector including the center rib 7 may be bolted (FIG. 7A). Alternatively, only the central rib may be fixed by bolts (FIG. 9B). Also in this case, since the welding line length can be reduced, the welding operation can be simplified and the manufacturing cost can be reduced.
Further, the circumferential ribs 8 may be fixed by bolts (not shown). Further, although the required design strength can be obtained by bolt fixing, the ribs 7 and 8 and the bolt 11 can be used in a complicated combination in consideration of the flow of the water to be sealed. Although not shown, the ribs 7 and 8
Can be replaced by the bolt 11.

[Second Embodiment] FIG. 6 is a partial sectional view showing a structure of a vacuum vessel according to a second embodiment of the present invention. In the sector 60, a rib 63 is provided diagonally between the inner wall 61 and the outer wall 62, and a shielding plate 64 is diagonally stacked along the rib 63. Spacers 65 are arranged between the shielding plates 64, and the bolt seats 66 and the holding blocks 67 are also fixed obliquely by welding. The shielding plate 64 is an obliquely screwed bolt 69 (not a structural material).
And fix it in position while inserting it in sequence. The outer wall 62 is fixed by screwing and fastening a nut 68 to a bolt 69. The material of the shielding plate 64 is the same as that of the first embodiment.

When the ribs are provided perpendicular to the inner wall, the radiation penetrates in the vertical direction. However, by installing the ribs 63 obliquely and laminating the shielding plate 64 along the ribs 63, the vacuum Even when the radiation generated in the container proceeds in the direction perpendicular to the inner wall 61, the shielding plate 64
And it becomes extremely difficult to penetrate. By arranging the rib 63 more obliquely, the radiation shielding performance is further improved.
In the configuration shown in FIG. 3, it is not necessary to use bolts instead of ribs as in the first embodiment.

FIG. 7 is a partial sectional view showing a modification of the vacuum vessel according to the second embodiment. The sector 70 of this vacuum vessel has the bolts 11 of the sector 50 of the first embodiment installed obliquely. When the bolt 11 is used as a structural material, its diameter becomes large. Therefore, when the bolt 11 is installed in the vertical direction on the inner wall 4, radiation is easily transmitted. Therefore, as shown in the figure, the bolts 11 are installed obliquely, and the bolt holes 13 of the shielding plate 12 are sequentially provided obliquely along the same. Thereby, radiation transmitted through the bolt 11 can be made extremely small. When the bolt 11 is provided diagonally, the bolt seat 6
Further, it is necessary to fix the holding block 16 obliquely.
Although not shown, the ribs 7 on both sides of the bolt may be installed obliquely as shown in FIG. This can further prevent the transmission of radiation.

[0027]

As described above, in the vacuum vessel of the nuclear fusion device according to the present invention (claim 1), a structure in which a bolt is passed between an inner wall and an outer wall constituting a sector to fix the inner wall and the outer wall. And a plurality of shielding plates were laminated and fixed by the bolts. In the vacuum vessel of the nuclear fusion device of the present invention (claim 2), ribs are provided on the inner wall of the sector, bolts are erected on the inner surface of the inner wall, and the shielding plates are laminated and fixed by the bolts, and the outer wall of the outer wall is fixed. An outer wall was attached to the bolt hole through a bolt, and the periphery of the bolt hole and the bolt were fixed from the outer surface of the outer wall. Therefore, since the bolt functions as a rib, the number of ribs used for the sector is reduced, and the overall weld line length is shortened. As a result, assembly of the vacuum vessel can be simplified, and manufacturing costs can be reduced.

Further, in the vacuum vessel of the nuclear fusion device of the present invention (claims 3 and 4), the bolts or ribs are provided to be inclined from the direction perpendicular to the inner wall surface and the outer wall surface. Even when radiation is emitted in a substantially vertical direction, the radiation is shielded by the shielding plate. For this reason, leakage of radiation to the outside through bolts or ribs can be extremely reduced.

In the vacuum vessel for a nuclear fusion device according to the present invention (claim 5), in the vacuum vessel for a fusion device in which a plurality of annular sectors are connected, the sector has a plurality of ribs between an inner wall and an outer wall. Since the shield plate is provided obliquely and the shielding plates for shielding radiation are obliquely laminated along the ribs, the leakage of radiation can be extremely reduced as described above.

[Brief description of the drawings]

FIG. 1 is a plan view showing a sector outer wall of a vacuum vessel according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a sector inner wall of the vacuum vessel of the present invention.

FIG. 3 is an assembly view of the sector shown in FIGS. 1 and 2;

FIG. 4 is a partial cross-sectional view when a sector is assembled.

FIG. 5 is a plan view showing a modification of the sector shown in FIG.

FIG. 6 is a partial cross-sectional view showing a structure of a vacuum vessel according to a second embodiment of the present invention.

FIG. 7 is a partial cross-sectional view illustrating a modified example of the vacuum vessel according to the second embodiment.

FIG. 8 is a configuration diagram showing a vacuum vessel used in a conventional fusion device.

9 is a partial sectional view of the vacuum vessel shown in FIG.

[Explanation of symbols]

 1a, 1b Outer wall 2 Outer skin 3 Bolt hole 4a, 4b Inner wall 5 Inner skin 6 Bolt seat 7, 8 rib 9 Port hole 10 Port short pipe 11 Bolt 12 Shielding plate 13 Bolt hole 14 Spacer 15 Screw-in groove 16 Holding block 17 Nut 50 sector

Claims (5)

[Claims] 1. A vacuum vessel of a fusion device in which a plurality of annular sectors are connected, wherein said sectors have a structure in which a plurality of ribs are provided between an inner wall and an outer wall, and furthermore, a bolt is provided between the inner wall and the outer wall. And a plurality of shielding plates for shielding radiation are laminated and fixed by the bolts, the vacuum vessel having a structure for fixing the inner wall and the outer wall. 2. A vacuum vessel of a fusion device in which a plurality of annular sectors are connected, a rib is provided on an inner wall of the sector, and a bolt is erected on an inner surface of the inner wall facing the inner surface of the outer wall to shield radiation. A vacuum vessel for a nuclear fusion device, characterized in that a shielding plate to be laminated is fixed by the bolts, an outer wall is attached to a bolt hole of the outer wall through a bolt, and a peripheral edge of the bolt hole and the bolt are fixed from the outer surface of the outer wall. 3. The vacuum vessel for a nuclear fusion device according to claim 1, wherein said bolts are further provided to be inclined from directions perpendicular to the inner wall surface and the outer wall surface. 4. The apparatus according to claim 1, wherein said rib is provided between the inner wall and the outer wall so as to be inclined, and a shielding plate for shielding radiation is obliquely laminated along the rib. A vacuum vessel for a nuclear fusion device according to any one of the preceding claims. 5. A vacuum vessel for a fusion device in which a plurality of annular sectors are connected, wherein said sectors have a structure in which a plurality of ribs are inclined between an inner wall and an outer wall, and radiation is applied along the ribs. A vacuum vessel for a fusion device, wherein shielding plates for shielding are obliquely stacked.