JP2001066389A - First wall / breeding blanket - Google Patents

Abstract

(57) [Summary] [Problem] To simplify the cooling system by continuously connecting the cooling system of the first wall and the cooling system of the blanket container. The first wall can reliably remove the heat load from the plasma, and further increase the neutrons. The coolant gas flows uniformly through the zone of the doubled material and the tritium breeding material, and at the same time, the generated tritium can be recovered. SOLUTION: A first wall / breeding blanket in which a structural material is a SiC / SiC composite material and a coolant is a gas, and a flow channel through which the coolant flows inside the first wall facing the plasma is provided. In a first wall / breeding blanket, a porous wall is provided on a back surface of the first wall so that a coolant flows through the porous wall into a neutron multiplier / tritium breeding material region in a container. The flow path through which the coolant flows is composed of a flow path on the front side and a plenum formed on the back surface that is folded back from one end thereof.
Breeding blanket.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a first wall / breeding blanket of a fusion reactor, and more particularly to a first wall having an excellent heat removal effect and a blanket having a simple structure and a simple cooling system and tritium recovery system. A first wall / breeding blanket comprising a container.

[0002]

2. Description of the Related Art In a conventional fusion reactor design, a first wall / breeding blanket structural material is made of a metal material such as stainless steel, and a blanket container in which a cooling pipe is disposed is faced with a first wall facing a plasma. And a neutron multiplier such as beryllium and a tritium breeder such as lithium oxide are installed in the container. Heat generated in the region of the neutron multiplier and the region of the tritium breeding material is removed by the coolant flowing inside the cooling pipe arranged in the container. With the blanket container having such a configuration, the production and heat removal of tritium, which is the purpose of the breeding blanket, can be achieved.

[0003] However, stainless steel is activated by neutrons generated by a nuclear fusion reaction and generates strong radiation even after the reactor is shut down, so that there has been a problem that it is difficult to disassemble and repair by a remote device. In addition, since the generation of radiation lasts for a long time, there was also a problem in waste management after decommissioning the furnace. Further, since the maximum operating temperature of stainless steel is about 500 ° C., water is usually used as a coolant, and the plant efficiency is about 30 ° C.
%. In addition, since high-temperature gas cannot be adopted, a gas turbine power generation system cannot be applied, and high plant efficiency cannot be achieved.

[0004] On the other hand, the SiC / SiC composite material has a very low amount of activation products, and as shown in FIG. It is considered to be promising as a structural material for a breeding blanket for a fusion reactor for power generation with high plant efficiency, and is being designed. In this case, the first wall / breeding blanket is also established by replacing the structural material of the stainless steel blanket with the SiC composite.

As described above, even in the prior art, SiC / S
A first wall / breeding blanket with iC composite as the structural material is established. However, this first wall / breeding blanket
There were inconveniences as described below. Since the cooling system for the first wall and the cooling system for the breeding material region are separate systems, the connection of the cooling pipe is complicated, and when the SiC / SiC composite material, which is difficult to weld, is used as the structural material, high reliability is obtained. The production method has not been established. Since the first wall receives heat directly from the plasma, the temperature of the structural material must be lower than the achievable coolant temperature in the breeding zone in order to maintain it below an acceptable value (about 1000 ° C.). As a result, plant efficiency decreases. It is necessary to separately provide a purge gas system for collecting the produced tritium, and the system becomes complicated. As another blanket structure, a structure as shown in FIG. 7 is conceivable. However, since the flow rate of the coolant changes and the shape of the cooling pipe changes depending on the place, the first wall, which is particularly severe in heat load, is removed. The heat capacity may be partially reduced, and sufficient heat removal may not be possible.

[0006]

Accordingly, the present invention is intended to simplify the cooling system of the first wall by continuously connecting the cooling system of the blanket container, and the first wall reliably removes the heat load from the plasma. It is another object of the present invention to provide a first wall / breeding blanket which allows the coolant gas to flow uniformly through the neutron multiplier and the tritium breeding material region while recovering the generated tritium.

[0007]

According to the first aspect of the present invention, there is provided a first wall / breeding blanket having a structure material of S
An iC / SiC composite, a first wall / breeding blanket in which the coolant is a gas, wherein a flow channel through which the coolant flows is provided inside the first wall facing the plasma, and a porous material is provided on the back of the first wall. A first wall / breeding blanket provided with a wall so that the coolant flows through the porous wall into the neutron multiplier / tritium breeding material region in the vessel, the flow path through which the coolant inside the first wall flows Is characterized by comprising a flow path on the front side and a plenum formed on the back surface that is folded back from one end thereof.

In the above-mentioned first wall / breeding blanket, the flow path on the front side of the flow path through which the coolant of the first wall flows is obtained by dividing the surface facing the plasma into upper, lower, left and right quarters. In each region, a flow path that flows from a vertical direction and bends 90 degrees in a horizontal direction and a flow path that flows from a horizontal direction and bends 90 degrees in a vertical direction alternately are formed. Are preferably connected to plenums at the back of the first wall.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the first wall / breeding blanket of the present invention will be described with reference to FIGS. 1 and 2. Reference numeral 1 denotes a first wall using a SiC / SiC composite material as a structural material and a gas as a coolant. A / breeding blanket, the first wall 2 facing the plasma is provided on the front side of the blanket container 3. A large number of flow paths 4 through which the coolant gas flows are provided in parallel inside the first wall 2, and a plenum (space) 5 is formed on the back surface of the first wall 2, that is, on the surface on the side of the blanket container 3.
The blanket container 3 faces the plenum (space) 5.
Is provided with a porous wall 6 through which coolant gas passes. The front of the blanket container 3 is filled with a neutron multiplier 7 such as beryllium, and the rear is filled with a tritium breeding material 8 such as lithium oxide. A coolant gas outlet passage 9 is provided at the center of the back surface of the blanket container 3, and the coolant gas outlet passage 9 is connected to a high-temperature pipe 10. A flow path 11 connected to the inlet of the flow path 4 of the first wall 2 through which the coolant gas flows is connected to a cooling pipe 12. A preferred example of the flow path 4 through which the coolant gas flows inside the first wall 2 will be described. As shown in FIG. 3, the surface facing the plasma is divided into upper, lower, left and right quarters. In each area, flow from vertical to horizontal 90
The flow path 4a is formed by alternately arranging the flow path 4a flowing in a bent direction and the flow path 4b flowing in a bent direction by 90 degrees from the horizontal direction. The outlets of the flow paths 4a and 4b are shown in FIGS. As shown in the figure, each is communicated with a plenum (space) 5 on the back surface of the first wall 2.

In the first wall / breeding blanket 1 of the embodiment configured as described above, the coolant gas, for example, He gas (in the case of carbon dioxide gas depending on temperature conditions) is supplied from the cooling pipe 12 shown in FIGS. Flows through the coolant channel 11 on the side of the blanket container 3 and flows through the channel 4 of the first wall 2, wraps around from one end, and flows around a plenum (space) 5 formed on the back surface which is continuous. After cooling the first wall 2, a region where He gas permeates the porous wall 6 in front of the blanket container 3 in the plenum (space) 5 and is filled with beryllium or the like as the neutron multiplier 7 in the blanket container 3. Into the region filled with tritium oxide or the like as tritium breeding material 8,
The heat is removed from these regions, and the tritium produced in the tritium breeding material region is recovered by He gas. Then, the He gas is sent from the cooling gas outlet passage 9 to the tritium recovery device (not shown) via the high-temperature piping 10.

In the first wall 2, a constant flow rate of the coolant can be secured by the flow path 4 having a constant flow path cross section shown in FIG.
Heat is removed by forced convection in the pipe, which is highly reliable. However, in the flow path 4 having the flow path configuration shown in FIG. To 9
The flow is bent at 0 ° C., flows from the horizontal direction in the flow path 4b, bends 90 degrees in the vertical direction, flows back to the back from the outlet end, and flows around the plenum (space) 5 shown in FIGS. Therefore, the entire surface of the first wall 2 has independent flow paths 4
a and 4b allow more reliable heat removal and have a rectangular shape as viewed from the plasma, and
Since the flow passages 4a and 4b in each region of the region are uniformly arranged, the nuclear heat generation inside the first wall 2 is removed, the temperature distribution becomes uniform, and the generation of excessive thermal stress can be avoided. it can.

[0012]

As can be seen from the above description, the cooling system of the first wall / breeding blanket of the present invention is simplified because the cooling system of the first wall and the cooling system of the blanket container are continuous. In addition, the cooling system of the first wall has a uniform flow path, so the first wall can reliably remove the thermal load from the plasma, the temperature distribution becomes uniform, and the generation of excessive thermal stress is avoided. it can. Further, since the porous wall is provided on the back surface of the first wall, the coolant gas flows uniformly into the neutron multiplier region and the tritium breeding material region, and it is possible to efficiently remove heat from these regions. In addition, the produced tritium can be stably recovered.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating one embodiment of a first wall / breeding blanket of the present invention.

FIG. 2 is a schematic cross-sectional view showing one embodiment of the first wall / breeding blanket of the present invention.

FIG. 3 shows a preferred arrangement of the first wall coolant gas passages in the first wall / breeding blanket of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 3;

FIG. 6 is a graph showing changes in radiation dose rates of various structural materials of the breeding blanket after shutting down the furnace.

FIG. 7 is a schematic sectional view showing a main part of a conventional first wall / breeding blanket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 First wall / breeding blanket 2 First wall 3 Blanket container 4 Coolant gas flow path inside first wall 4a Vertical flow path 4b Horizontal flow path 5 Plenum 6 Porous wall 7 Neutron multiplier 8 Tritium breeder

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Adachi 2-6-5 Minamisuna, Koto-ku, Tokyo Kawasaki Heavy Industries, Ltd. Tokyo Design Office (72) Inventor Yasushi Seki 801 Mukaiyama, Machiyama, Naka-machi, Naka-gun, Ibaraki Prefecture Address No. 1 Inside the Japan Atomic Energy Research Institute Naka Research Center (72) Inventor Shuzo Ueda 801 Nakamura-cho, Naka-gun, Ibaraki Pref. Ryoichi Kurihara, 801-1 Mukaiyama, Naka-cho, Naka-gun, Ibaraki Pref.

Claims (2)

[Claims] 1. A first wall / breeding blanket in which a structural material is a SiC / SiC composite material and a coolant is a gas, and a flow channel through which a coolant flows is provided inside the first wall facing the plasma. A first wall / breeding blanket, wherein a porous wall is provided on the back of the first wall so that the coolant flows through the porous wall into the neutron multiplier / tritium breeding material region in the blanket container; A first wall / breeding blanket, wherein a flow path through which an internal coolant flows is constituted by a flow path on the front side and a plenum formed on a back surface that is folded back from one end thereof. 2. The first wall / breeding blanket according to claim 1, wherein the flow path on the front side divides the surface facing the plasma into quarters of the upper, lower, left and right directions, and in each area, from the vertical direction. The flow path is formed by alternately arranging a flow path bent at 90 degrees in the horizontal direction and a flow path bent at 90 degrees in the vertical direction from the horizontal direction, and each flow path has an outlet at the back of the first wall. A first wall / breeding blanket, wherein the first wall / breeding blanket is in communication with a plenum of