JP3582001B2 - How to prevent deformation of breeding cans - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of preventing deformation of a breeding can in a breeding area of a first wall / breeding blanket of a fusion reactor.
[0002]
[Prior art]
The first wall / breeding blanket 1 shown in FIG. 4 of the fusion reactor is attached by welding the mounting feet 2 on both the left and right sides to the back plate 3. The first wall / breeding blanket 1 has a first wall 5 facing the plasma in front of the blanket container 4 and has a cooling passage 6 inside it. On the left and right sides of the breeding region 7 in the blanket container 4, breeding cans 8 filled with tritium breeding material and cooling plates 9 are alternately arranged at intervals, and cooling walls 10 are provided on the right and left boundaries. Around these, Be, which is a neutron multiplier, is filled, and a purge gas tube 11 is provided before and after the breeding can 8 in the Be filled portion. Each propagation can 8 is provided with a purge gas tube 12.
[0003]
As a method for producing fuel T (tritium) for a fusion reactor, there is a method based on a nuclear reaction between Li (lithium) and neutrons. However, Li alone cannot be used because its melting point is low. Therefore, it is conceivable to use a pebble Li ₂ O (lithium oxide) having a diameter of 1 mm as the Li compound.
[0004]
By the way, as shown in the conceptual diagram of FIG. 5, when lithium oxide 20 having a diameter of 1 mm is put in a stainless steel breeding can 8 having a thickness of 1 mm in a stainless steel blanket container 4 which is an outer box, the operation time is reduced. The thermal stress acts to expand the growth can 8. As a result, the lithium oxide 20 uniformly contained in the breeding can 8 falls downward, and a gap is formed in the upper part of the breeding can 8, the temperature there rises, and the breeding rate of the lithium oxide 20 decreases. .
[0005]
In order to prevent the growth rate of the lithium oxide 20 from decreasing, it is necessary to prevent a gap from being formed in the upper part of the breeding can 8, and to prevent the breeding can 8 from spreading due to thermal stress during operation. is necessary.
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for preventing deformation of a breeding can which absorbs the force of spreading the breeding can due to thermal stress during operation and prevents deformation.
[0007]
[Means for Solving the Problems]
A method for preventing deformation of a breeding can according to the present invention for solving the above-mentioned problems is characterized in that a bellows or a leaf spring having a plate at a tip thereof is provided at the center of the front and rear surfaces of the breeding can in a breeding region of a first wall / breeding blanket of a fusion reactor. Alternatively, a support plate made of a shape memory alloy is fixed to the direction perpendicular to the breeding can, and the force of spreading the breeding can due to thermal stress during operation is applied to the bellows plate or plate spring or a support made of a shape memory alloy. It is characterized in that the plate comes into contact with and absorbs a cooling plate or an inner wall of a blanket container.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of a method for preventing deformation of a growth can according to the present invention will be described with reference to FIG. 1. Bellows 22 each having a plate 21 at the end thereof are interposed at the center of the front and rear surfaces of a growth can 8 filled with lithium oxide via a substrate 23. The plate 21 of the bellows 22 is shown in FIG. 4 with the force that the growth can 8 becomes 800 ° C. or higher during operation and spreads in the front-rear direction as indicated by the arrow. The breeding can 8 is absorbed by coming into contact with the cooling plate 9 and the inner surface of the blanket container 4 to prevent the growth can 8 from being deformed.
[0009]
Another embodiment of the method for preventing deformation of a breeding can of the present invention will be described with reference to FIG. 2. At the center of the front and rear surfaces of a breeding can 8 filled with lithium oxide, a support plate 24 made of a shape memory alloy is provided with a substrate 23. The breeding can 8 is fixed in a direction perpendicular to the breeding can 8, and the breeding can 8 becomes 800 ° C. or higher during operation, and the force that spreads in the front-rear direction as indicated by the arrow due to thermal stress is applied to the support plate 24 made of a shape memory alloy. Is absorbed by contacting the cooling plate 9 and the inner surface of the blanket container 4 shown in FIG. Note that a shape memory alloy that starts to elongate at 800 ° C. or higher and does not change at a temperature lower than 800 ° C. is used.
[0010]
A further embodiment of the method for preventing deformation of a breeding can according to the present invention will be described with reference to FIG. 3. Substrates 23 are fixed on the front and rear surfaces of a breeding can 8 filled with lithium oxide. At the upper and lower end portions, a radius 25 having a small curvature is formed so as to protrude from the front surface, and a radius 26 having a large curvature is formed in the middle so as to be recessed from the front surface. The force of 800 ° C. or higher, which spreads in the front-rear direction due to thermal stress as shown by the arrow, is absorbed by contacting the leaf spring 27 with the inner surface of the cooling plate 9 or the blanket container 4 shown in FIG. Prevent deformation.
[0011]
As can be seen in each of the above embodiments, the propagation can 8 is prevented from spreading in the front-rear direction due to thermal stress during operation, and the lithium oxide uniformly contained in the propagation can 8 does not fall down. No gap is formed in the upper portion of the can 8, so that the temperature does not increase at the upper portion and the growth rate of lithium oxide does not decrease.
[0012]
【The invention's effect】
As can be understood from the above description, according to the method for preventing deformation of the breeding can of the present invention, the force at which the breeding can spreads in the front-rear direction due to thermal stress during operation is a bellows or leaf spring having a plate at the tip or a shape memory alloy. The supporting plate made of stainless steel is absorbed by contacting the inner wall of the blanket container and the cooling plate, preventing deformation of the breeding can and preventing the lithium oxide evenly contained inside from falling down. Does not occur, the temperature does not rise, and the growth rate of lithium oxide does not decrease.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing one means for carrying out the method for preventing deformation of a breeding can of the present invention.
FIG. 2 is a schematic perspective view showing another means for carrying out the method for preventing deformation of a multiplication can of the present invention.
FIG. 3 is a schematic perspective view showing still another means for carrying out the method for preventing deformation of a breeding can according to the present invention.
FIG. 4 is a cross-sectional view showing a first wall / breeding blanket of a fusion reactor.
FIG. 5 is a conceptual diagram of a breeding can in a blanket container.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 First wall / breeding blanket 4 Blanket container 7 Breeding area 8 Breeding can 9 Cooling plate 20 Lithium oxide 21 Plate 22 Bellows 23 Substrate 24 Shape memory alloy supporting plate 27 Leaf spring

Claims (1)

At the center of the breeding can in the breeding area of the first wall / breeding blanket of the fusion reactor, a bellows with a plate at the tip or a leaf spring or a support plate made of a shape memory alloy are oriented at right angles to the breeding can. The bellows plate or leaf spring or a support plate made of a shape memory alloy is absorbed by contacting the bellows plate or the leaf spring or the support plate made of a shape memory alloy with the cooling plate or the inner wall of the blanket container during operation. A method for preventing deformation of a breeding can.

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