JP3810935B2 - Fusion reactor reactor structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reactor structure in a passive shell region such as a vacuum vessel or a blanket support structure of a fusion apparatus.
[0002]
[Prior art]
Reactor structures such as fusion vessel vacuum vessels and blanket support structures are large torus structures, so they are generally manufactured in the form of multiple sectors in the toroidal direction, and between the sectors on-site. It is assembled by welding. In the local connection between sectors, a splice plate is usually used for the local connection part in order to absorb manufacturing accuracy etc. In the case of a furnace structure with a double wall structure inside and outside, it is spatial. Because of this restriction, the outer wall must be connected from the inside of the furnace structure and connected to the outer wall, and therefore, the use of a splice plate is inevitable at least for the inner wall. In addition, a splice plate that is divided into a plurality of pieces in the poloidal direction is used because of the ease of local alignment of the splice plate and restrictions on the geometric shape.
[0003]
In addition, a passive shell is used to ensure the stability of the plasma generated inside the furnace structure. It is made of a material with low electrical resistance, such as a copper alloy, and is installed in a furnace structure that is closest to the plasma and continuous in the toroidal direction. In this case, it is desirable that the passive shell is continuous in the toroidal direction.
[0004]
Since the inter-sector connection part of such a furnace structure makes a round in the poloidal direction, in order to continuously form the passive shell in the toroidal direction, the existing passive shells in the sector are connected in the toroidal direction at the inter-sector connection part. It is necessary to connect it electrically. In this case, the reactor structure has nuclear heat generated by the neutrons resulting from the fusion reaction, and electromagnetic force acts when the plasma collapses, so the passive shell structure at the inter-sector connection part can withstand these heat loads and electromagnetic force loads. Must be a thing. Since the nuclear heat generation is volumetric heat generation, it is necessary to shorten the heat conduction distance to the cooling surface in order to efficiently cool the passive shell. Furthermore, since the passive shell is a good conductor, an eddy current tends to flow, and since it is generally a thin shell, the passive shell needs to be firmly supported.
[0005]
Next, an example of a conventional structure in which a passive shell is installed in a vacuum vessel will be described with reference to FIGS.
FIG. 6 is a schematic diagram showing only adjacent vacuum vessel sectors of a double-walled torus-like vacuum vessel comprising an inner wall 1 and an outer wall 2. A blanket is installed on the inner surface of almost the entire inner wall of the vacuum vessel, but this is omitted in FIG. 6 for the sake of clarity.
[0006]
In FIG. 6, the vacuum vessel sector 3a and the vacuum vessel sector 3b are connected once in the poloidal direction at the inter-sector connection portion. However, in order to absorb the manufacturing error of the sector, the connection between the sectors is usually a splice plate. Is used. The passive shells 5 are installed at the upper part and the lower part on the vacuum vessel outboard side, and each makes a round in the toroidal direction. Therefore, in the sector connection part 4, it is necessary to weld-connect between adjacent sectors and to electrically connect the passive shells 5 provided in the adjacent sectors in the toroidal direction.
[0007]
FIG. 7 is a cross-sectional view (toroidal cross-sectional view) of the vacuum vessel sector connection region in the cross-section in the VII-VII direction of FIG.
In FIG. 7, the passive shell 5 is joined to the inner wall 1, but at the inter-sector connection portion, the splice plate 9 is used to weld and connect the vacuum vessel sector 3 a and the vacuum vessel sector 3 b to form the weld joint 13. The passive copper of the adjacent sector is electrically connected by fixing the connecting copper plate 10 with bolts 11. Further, the inner wall 1 and the outer wall 2, the passive shell 5, the connection copper plate 10 and the bolt 11 are cooled by flowing cooling water through the cooling passage 6 made of the inner wall 1, the outer wall 2 and the poloidal rib 7 connecting them. Moreover, although the blanket 8 is installed in the inner wall 1, it is normally cooled with the cooling water of a different system from the vacuum vessel.
[0008]
By the way, there are the following problems in the vacuum container of the conventional structure as described above.
[0009]
(1) The passive shell 5 does not need to be thicker than necessary. In the case of a copper plate passive shell, approximately 5 to 6 mm is used. Therefore, since the connecting copper plate 10 is also as thin as its mechanical rigidity, the electromagnetic force acting on the connecting copper plate 10 at the time of rapid plasma extinction is small even when the electromagnetic force for supporting the bolt 11 is small. Several bolts are required.
[0010]
(2) Since the connection copper plate 10 is fixed by the bolt 11, there is a large contact thermal resistance between the connection copper plate 10 and the inner wall 1. For this reason, since there is a limit to the heat removal capability of the connection copper plate 10, application to the conventional structure as shown in FIG. 7 is limited to a case where the heat load on the furnace wall is small.
[0011]
(3) Since the bolt 11 is used under a heat repetitive environment and an electromagnetic force generated in pulses, it is easy to loosen. In addition, it is very difficult to check the soundness of the bolts, including the holding of the fastening force during operation, and it takes a long time for maintenance and inspection, which reduces the operating rate of the fusion device.
[0012]
(4) The bolt fastening structure requires tapping, but when the number of bolts increases, this tapping takes a long time. Further, when the inner and outer walls between the sectors are connected by welding, welding deformation occurs, and therefore a connecting step of the connecting copper plate 10 is required. Since such a process is required, it takes a long time to manufacture the vacuum vessel.
[0013]
[Problems to be solved by the invention]
As described above, the reactor structure of the conventional fusion device has a problem of low structural reliability due to insufficient countermeasures against electromagnetic force and thermal stress, and it takes a lot of time for maintenance and inspection. There was a problem that the operating rate of the apparatus was lowered, and further, there was a problem that the production time was long.
[0014]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a reactor structure of a nuclear fusion apparatus that has a simple structure and high reliability and that can shorten the manufacturing time.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, claim 1 of the present invention provides a reactor structure of a fusion apparatus in which a plurality of reactor structure sectors are connected using a plurality of splice plates, and a splice plate in a passive shell region is provided. It is composed of a passive shell material with low electrical resistance, such as copper or copper alloy, and a clad material composed of the same type of structural material as the structural material of the furnace structure, and the structural material of the splice plate and the structural material of the furnace structure sector In addition, the passive shell part of the splice plate and the passive shell part of the furnace structure sector are built up by welding or spraying using a passive shell material, and these passive shells are electrically connected. And
[0016]
According to the first aspect, since the passive shell portion of the adjacent furnace structure sector is electrically connected by means of overlaying using the passive shell material, the contact thermal resistance and electromagnetic force between the passive shell material and the structural material. Not only can the problems related to support be solved, but work such as mating and tapping is not necessary for the build-up, so the production period can be considerably reduced.
[0017]
According to a second aspect of the present invention, in the reactor structure of the nuclear fusion apparatus according to the first aspect, the splice plate structural material and the structural material of the reactor structure sector are welded and the final welding pass of the welded joint to be welded Overlay welding of nickel over the surface of the metal and its vicinity in the final welding pass , or over the surface area of the final welding pass and part of the surface of the passive shell material, and overlay welding of the passive shell material It is characterized by.
[0018]
According to claim 2, nickel serves as a barrier to prevent weld cracks caused by the passive shell material being melted into the structural material at the time of build-up welding of the passive shell material, and therefore, high structural soundness can be achieved with respect to this sector connection portion. Obtainable.
[0019]
Claim 3 of the present invention is characterized in that, in the reactor structure of the fusion apparatus according to claim 1, the build-up welding using the passive shell material is powder plasma welding using the powder of the passive shell material. To do.
According to the third aspect, the welding can be simplified and the construction time can be shortened as compared with ordinary TIG (MAG) welding.
[0020]
According to a fourth aspect of the present invention, in the reactor structure of the fusion apparatus according to the first aspect, a plurality of splice plates are installed in the passive shell region, and between the adjacent splice plate passive shells on the poloidal end surface side of the splice plate. Is characterized by not depositing passive shell material.
[0021]
According to the fourth aspect, since the poloidal gap between the passive shells of the adjacent splice plates is small, the function of the passive shell is not impaired even if the passive shells are not electrically connected in the poloidal direction by the adjacent splice plates. Therefore, the manufacturing period of the furnace structure can be greatly shortened.
[0022]
According to a fifth aspect of the present invention, in a reactor structure of a nuclear fusion apparatus in which a plurality of reactor structure sectors are connected using a plurality of splice plates, a passive material composed of a clad material composed of a passive shell material and a structure material. The end surface of the passive shell material in the shell region is characterized by a predetermined plane slope or concave slope.
[0023]
Generally, the furnace structure has a large nuclear heat generation and a large temperature gradient is generated along the heat conductor. For example, a passive shell material such as a copper alloy and a structural material such as austenitic stainless steel have different thermal expansion coefficients. For this reason, there is a concern that a large thermal stress is concentrated on the end face of the passive shell during operation of the furnace structure.
According to the fifth aspect, the concentration of the thermal stress can be relaxed and the structural integrity of the part can be improved.
[0024]
According to a sixth aspect of the present invention, in the reactor structure of the fusion device according to the fifth aspect, the position of the end face of the passive shell material at the structural welding site in the passive shell region is separated from the weld groove surface of the structural material by a predetermined distance. It is characterized by setting.
According to the sixth aspect, it is possible to solve the problems of welding cracking due to the entrainment of the passive shell material during welding of the structural material and the peeling of the passive shell material due to welding heat.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a toroidal sectional view showing a passive shell region of an inter-sector connection portion of a vacuum vessel of a nuclear fusion apparatus according to a first embodiment of the present invention (corresponding to claim 1).
[0026]
As shown in the figure, in this embodiment, the passive shell 5 is joined to the inner wall 1, and the connecting portion between the vacuum vessel sector 3 a and the vacuum vessel sector 3 b is the structural material of the splice plate 9 and the structural material of the inner wall 1. After forming the welded joint 13 by welding, a passive shell material having a low electrical resistance such as copper or copper alloy is built up between the passive shell portion of the splice plate 9 and the passive shell portion of the vacuum vessel. The built-up portion 14 is electrically connected to these passive shells. Further, cooling water is allowed to flow through the cooling passage 6 formed by the inner wall 1 and the outer wall 2 and the poloidal rib 7 connecting them. The blanket 8 is installed on the inner wall 1.
[0027]
According to the present embodiment, the passive shells between adjacent sectors are electrically connected by overlaying, so that not only the heat removal characteristics and the strength against electromagnetic force of the passive shell part of the sector connection part can be improved. Since the build-up is an extremely simple operation, the production period of the vacuum vessel can be considerably shortened.
[0028]
FIG. 2 is a toroidal cross-sectional view of the inter-sector connection portion of the vacuum vessel of the fusion device according to the second embodiment of the present invention (corresponding to claims 2 and 3), and corresponds to “A” portion of FIG. FIG. The same parts as those in the first embodiment of FIG. 1 are denoted by the same reference numerals, and redundant description is omitted. The same applies to the following embodiments.
[0029]
In this figure, in this embodiment, after welding the structural materials, the final weld pass surface of the inter-sector structural material welded joint 13, the surface of the inter-sector structural material welded joint 13 from which the passive shell has been removed, Nickel build-up part 15 is formed by build-up welding nickel on a part of the inclined end surface. Thereafter, the passive shell material is powder plasma welded to form the passive shell material build-up portion 14 to electrically connect the passive shells in adjacent sectors. The end of the passive shell is the inclined end surface 16.
[0030]
According to the present embodiment, by first depositing nickel, it is possible to prevent weld cracks caused by the passive shell material being melted into the structural material during the overlay welding of the passive shell material. Therefore, high structural soundness can be obtained with respect to this sector connection. Next, it is possible to facilitate the build-up operation of the passive shell by performing powder plasma welding using the powder of the passive shell, and to shorten the production period of the vacuum vessel. Furthermore, a series of operations for building up can be facilitated by inclining the end portion on the building side of the passive shell.
[0031]
FIG. 3 is a poloidal sectional view of an adjacent splice plate in the passive shell region of the inter-sector connection portion of the vacuum vessel of the fusion device according to the third embodiment (corresponding to claim 4) of the present invention.
[0032]
As shown in the drawing, in this embodiment, a narrow groove welding method is applied in welding of splice plates to form a splice plate weld joint 18 having a small groove opening, and the adjacent splice plates 17a and 17b are connected to each other. A passive shell material is not built between the passive shells 5 and 5.
[0033]
According to the present embodiment, the effective poloidal gap 20 between the passive shells 5 and 5 of the plurality of splice plates 17a and 17b in the passive shell region is reduced, and the build-up of the passive shell material in that portion is omitted. The production period of the vacuum vessel can be shortened.
[0034]
FIG. 4 is a poloidal sectional view showing a poloidal end portion of a passive shell of a vacuum vessel of a nuclear fusion apparatus according to a fourth embodiment of the present invention (corresponding to claim 5).
As shown in the figure, in this embodiment, the poloidal end surface of the passive shell 5 is formed on the concave end surface 21. That is, in the drawing, the end surface of the passive shell material has a concave slope, but it can also have a predetermined plane slope. The blanket is not shown.
[0035]
According to the present embodiment, the thermal stress concentration at the joint interface between the passive shell end face structure and the structure formed by the difference in thermal expansion coefficient between the passive shell material and the structural material is reduced, and a highly reliable vacuum vessel with a passive shell is obtained. be able to.
[0036]
FIG. 5 is a perspective view of a splice plate of a vacuum vessel of a nuclear fusion apparatus according to a fifth embodiment (corresponding to claim 6) of the present invention.
In the figure, in the present embodiment, the position of the end face of the passive shell material is set to a position separated by a predetermined distance 23 from the weld groove surface 22 of the structural material in the structural welding portion of the passive shell 5 region. Further, the passive shell end face is provided with an inclination angle 24.
ADVANTAGE OF THE INVENTION According to this invention, the problem of the welding crack by the winding of the passive shell material at the time of structural material welding, and the problem of peeling of the passive shell material by welding heat can be solved.
[0037]
【The invention's effect】
As described above, according to the present invention (corresponding to claims 1 to 6), there is a problem of low structural reliability and a long manufacturing time due to insufficient countermeasures against electromagnetic force and thermal stress. Since this can be solved, it is possible to provide a reactor structure of a nuclear fusion apparatus that has a simple and highly reliable structure and that can shorten the manufacturing time.
[Brief description of the drawings]
FIG. 1 is a toroidal cross-sectional view of a passive shell region of an inter-sector connection portion of a vacuum vessel of a nuclear fusion apparatus according to a first embodiment of the present invention.
2 is a toroidal cross-sectional view of an inter-sector connection portion of a vacuum vessel of a nuclear fusion apparatus according to a second embodiment of the present invention, and is an enlarged view of a portion corresponding to the “A” portion of FIG.
FIG. 3 is a poloidal sectional view of an adjacent splice plate in a passive shell region of a vacuum vessel of a nuclear fusion apparatus according to a third embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a poloidal end face of a passive shell of a vacuum vessel of a nuclear fusion apparatus according to a fourth embodiment of the present invention.
FIG. 5 is a perspective view of a splice plate of a vacuum vessel of a fusion device according to a fifth embodiment of the present invention.
FIG. 6 is a perspective view of two adjacent sectors of a conventional double-walled torus vacuum vessel.
7 is a cross-sectional view in the VII-VII direction of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inner wall, 2 ... Outer wall, 3a, 3b ... Vacuum container sector, 4 ... Inter-sector connection part, 5 ... Passive shell, 6 ... Cooling flow path, 7 ... Poloidal rib, 8 ... Blanket, 9 ... Splice plate, 10 ... Connection copper plate, 11 ... bolt, 12 ... arrow indicating the toroidal direction, 13 ... inter-sector structural material weld joint, 14 ... passive shell material build-up part, 15 ... nickel build-up part, 16 ... inclined end face, 17a, 17b ... passive Adjacent splice plate with shell, 18 ... weld joint between splice plates, 19 ... arrow indicating poloidal direction, 20 ... effective poloidal gap between passive shells, 21 ... concave end face, 22 ... weld groove surface of structural material, 23 ... structural material The distance between the weld groove surface and the passive shell end surface, 24... The inclination angle of the inclined end surface of the passive shell.

Claims (6)

  In a reactor structure of a fusion apparatus in which a plurality of reactor structure sectors are connected using a plurality of splice plates, the splice plate in the passive shell region is replaced with a passive shell material having a low electrical resistance such as copper or a copper alloy. It is composed of a clad material consisting of the structural material of the furnace structure and the same type of structural material, and the splice plate structural material and the structural material of the furnace structure sector are welded together, and further, by welding or spraying using a passive shell A reactor structure of a nuclear fusion apparatus, wherein a passive shell portion of a splice plate and a passive shell portion of a reactor structure sector are built up and the passive shells are electrically connected. The splice plate structural material and the furnace structural sector structural material are welded together, and the surface of the final weld pass of the weld joint to be welded and the vicinity of the surface of the final weld pass , or the surface region of the final weld pass and the passive shell The reactor structure of a nuclear fusion apparatus according to claim 1, wherein nickel is welded over a part of the material surface and further passive shell material is welded.   The reactor structure of a nuclear fusion apparatus according to claim 1, wherein the build-up welding using the passive shell material is powder plasma welding using the powder of the passive shell material.   2. The fusion device according to claim 1, wherein a plurality of splice plates are installed in the passive shell region, and no passive shell material is built up between adjacent splice plates on the poloidal end surface side of the splice plate. Furnace structure.   In the reactor structure of a nuclear fusion apparatus formed by connecting a plurality of reactor structure sectors using a plurality of splice plates, the end surface of the passive shell material in the passive shell region composed of the clad material composed of the passive shell material and the structural material A reactor structure of a nuclear fusion apparatus, characterized by having a predetermined plane inclination or concave inclination.   6. The reactor structure of a nuclear fusion apparatus according to claim 5, wherein the position of the end surface of the passive shell material is set at a predetermined distance from the weld groove surface of the structural material at the structural welding site in the passive shell region.

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