CN211742660U

CN211742660U - First wall with tritium resistance function for fusion reactor

Info

Publication number: CN211742660U
Application number: CN201922163894.7U
Authority: CN
Inventors: 才来中; 宋久鹏; 曾晓晓; 颜彬游; 黄向玫
Original assignee: Xiamen Tungsten Co Ltd; Southwestern Institute of Physics
Current assignee: Xiamen Tungsten Co Ltd; Southwestern Institute of Physics
Priority date: 2019-12-05
Filing date: 2019-12-05
Publication date: 2020-10-23
Anticipated expiration: 2029-12-05

Abstract

The utility model belongs to fusion reactor technique, concretely relates to a first wall that is used for fusion reactor to have and hinders tritium function. The plasma deposition device comprises a deposition layer, a middle layer and a substrate, wherein the deposition layer is a tungsten coating and is in direct contact with plasma, and the middle layer is a tritium-resistant coating and is positioned between the deposition layer and the substrate. The tungsten coating is used for replacing a tungsten block, the requirements of the working condition and the service life of the first wall are met, and the weight and the economical efficiency of the first wall structure are improved. The induced current and the corresponding electromagnetic load in the plasma operation process are obviously reduced, the harsh working condition requirement of the first wall in the fusion reactor can be met, and the tritium retention in the first wall is reduced, so that the tritium circulation efficiency of the fusion reactor is improved, and the requirements for tritium proliferation and tritium supply are reduced.

Description

First wall with tritium resistance function for fusion reactor

Technical Field

The utility model belongs to the fusion reactor technique, concretely relates to first wall with hinder tritium function.

Background

In a fusion reactor, where the plasma must be able to sustain combustion for a considerable period of time, the parts of the vacuum chamber that directly face these high temperature plasmas are called plasma-facing Parts (PFCs), which comprise a first wall and a divertor. Since they are directly faced with high temperature plasma, they involve important problems of high thermal load resistance, sputter corrosion, retention of hydrogen and its isotopes, neutron irradiation effect, and the like. In a fusion reactor, the first wall acts as a barrier to protect the inner wall of the reactor vacuum chamber from direct irradiation by high temperature plasma, and is one of the most severe and critical components of the fusion reactor. When plasma is applied to the surface of the component, the first wall can be subjected to steady and transient high thermal loads due to radiation and plasma exposure, causing corrosion and modification of the material surface, and driving deuterium and tritium fuel to penetrate into the interior of the first wall component, resulting in loss of fuel. Neutron irradiation acts on the whole to damage the plasma-facing component, resulting in material performance degradation, and significant changes in chemical composition, morphology, microstructure, and thermo-mechanical properties. The off-site damage generated by neutron irradiation can further provide an occupied space for tritium atoms, so that tritium fuel consumption is caused, and the safety and continuous operation capability of a reactor system are reduced. Meanwhile, in the heat absorbed by the first wall from the fusion reaction, the high heat flow induced by the plasma irradiation acts on the surface layer of the component, but can still cause the structural change of the material and the damage of the component connection interface (such as crack, peeling, ablation, melting and the like). Thus, the first wall structure of the fusion reactor is required to be able to withstand high steady-state and transient thermal loads, and to have less material erosion (including physical and chemical sputtering erosion, etc.), less tritium fuel retention and penetration in the plasma irradiation environment, while requiring less impact of neutron irradiation on the first wall structure.

Tungsten materials have been widely studied and used as the material of choice for plasma because of its high melting point, high thermal conductivity, low fuel retention, low physical sputtering, low activity, and other properties.

The low-activation steel (low-activation ferrite/martensitic steel-RAFM) has excellent physical and mechanical properties such as low activation performance, lower radiation swelling and thermal expansion coefficient, higher thermal conductivity and the like under the action of neutron irradiation, and relatively mature technical basis, and is widely selected as a fusion reactor structural material.

Similar designs and techniques exist primarily for unsteady-state operation of fusion experimental devices, not fusion reactors, but primarily divertor components. The design that the welding combination is carried out by adopting the block of forged tungsten and the low-activation steel material is mainly adopted, and the structures have no tritium resistance function and are not designed aiming at the operation working condition of the first wall of the fusion reactor in steady-state operation.

Tritium-resistant coatings in the prior art are primarily directed to the piping or cladding structure of fusion reactor tritium plants, which do not face the high thermal loads of steady and transient states and the effects of thermal fatigue due to transient plasma events, or which are subjected to small doses of neutron irradiation.

The intermediate layer or tritium-resistant coating of the prior art has one of the following characteristics:

(a) the connection of tungsten and low-activation steel uses a welding technology and does not have tritium resistance;

(b) the tungsten and the low activation steel cannot be effectively connected by combining the tungsten and the low activation steel by using a non-welding technology but not serving as an intermediate layer for connecting the tungsten and the low activation steel;

(c) the middle layer is of a multi-layer structure and is not a single-material middle layer;

(d) the middle layer has no tritium resistance;

(e) the intermediate layer contains fusion reactors of O, Ni, Mo and the like, and materials which are avoided or not preferentially used are contained;

(f) the tungsten material combined with the middle layer is a non-thick tungsten coating material or a non-high-purity tungsten material, and the thermal shock resistance is poor.

In a fusion reactor, the first wall must be ensured to have a good tritium resistance function, and the tritium accumulation is reduced, so that the requirements of tritium circulation and tritium propagation are ensured, and the necessary requirements of nuclear safety are met; and the combination of plasma-facing materials with structural materials needs to be performed.

Disclosure of Invention

The utility model aims at providing a first wall that is used for fusion reactor to have and hinders tritium function can satisfy in the fusion reactor to the harsh operating mode requirement of first wall, reduces tritium retention volume in the first wall part, improves fusion reactor tritium circulation efficiency, reduces the demand that tritium breeds and tritium supplies with.

The technical scheme of the utility model as follows:

a first wall with a tritium-resistant function for a fusion reactor, comprising a plasma-facing material, an intermediate layer and a fusion reactor structural material, the plasma material being in direct contact with a plasma, the intermediate layer being located between the plasma material and the fusion reactor structural material.

The plasma material is a tungsten coating.

The fusion reactor structural material is low activation steel.

The middle layer is a tritium-resistant coating.

The tritium-resistant coating is a titanium nitride layer.

The thickness of the intermediate layer is 1.5-2.5 microns.

The thickness of the tungsten coating is 0.5-1.5 mm.

The utility model discloses an effect as follows:

the first wall structure of design does not adopt the tungsten piece, but adopts the design of thick tungsten coating, can satisfy first wall operating mode requirement and life requirement completely, simultaneously because first wall area is very big, replaces the tungsten piece with thick tungsten coating, has improved economic nature greatly when having satisfied the weight requirement. In addition, the tungsten coating replaces a tungsten block, and induced current and corresponding electromagnetic load in the plasma operation process can be obviously reduced. Moreover, the first wall structure adopts a Chemical Vapor Deposition (CVD) thick tungsten coating process, and the prepared tungsten coating has the characteristics of high purity and good thermal shock resistance.

Because the thermal expansion coefficients of the tungsten and the low-activation steel material are different greatly, the fact that a single transition layer (in a non-welding mode) is used for effectively connecting the tungsten and the low-activation steel in the prior art is not seen, the method adopts a single coating form of titanium nitride (TiN) or a similar tritium-resistant coating, the tungsten and the low-activation steel material can be effectively connected, and meanwhile, the first wall structure has good tritium-resistant capacity.

The first wall structure is made of structural material low-activation steel as a base body, the middle layer is a titanium nitride ceramic or similar tritium-proof permeation layer, and the outermost layer is a thick tungsten coating facing plasma. The tritium production device can meet the harsh working condition requirements (high heat load, strong plasma beam current, neutron irradiation and the like) of the first wall in the fusion reactor, and reduces tritium retention in the first wall, so that the tritium circulation efficiency of the fusion reactor is improved, and the requirements for tritium proliferation and tritium supply are reduced.

Drawings

FIG. 1 is a schematic view of a first wall with tritium-resistance for a fusion reactor;

in the figure: 1. plasma; 2. depositing a layer; 3. an intermediate layer; 4. a substrate.

Detailed Description

The invention is further illustrated by the accompanying drawings and the detailed description.

As shown in fig. 1, the first wall with tritium-resistance function for a fusion reactor comprises a facing deposit 2, an intermediate layer 3 and a substrate 4. The substrate 4 is the fusion reactor structure surface.

In which the plasma-facing material 2 is in direct contact with the plasma 1, and between the deposited layer 2 and the substrate 4 is an intermediate layer 3.

The deposition layer 2 is a tungsten coating, the substrate 4 is a laminated structure made of low-activation steel, namely the surface of the fusion reactor structure, and the middle layer 3 is a titanium nitride layer or a tritium-resistant coating.

The tungsten coating-intermediate layer-low activation steel layered structure constitutes a sandwich structure of the first wall.

The middle layer 3 has the connecting function and the tritium resistance function, can reliably combine the tungsten coating and the low-activation steel, effectively solves the thermal stress problem of the tungsten and the steel under the working condition of the first wall, and ensures that the tungsten and the steel have good combination performance; meanwhile, the titanium nitride or similar tritium-resistant coating has good tritium-resistant performance, can effectively prevent tritium permeation, reduces tritium retention of the first wall structure, and improves the tritium cycle efficiency of the fusion reactor.

The deposition layer 2 is a high-purity and full-compact thick tungsten coating. The purity of tungsten is 99.9999 wt.%, and the thickness of the coating is 0.2-3 mm;

the middle layer 3 is of a single transition layer structure, a titanium nitride layer or other tritium-resistant coatings, and the thickness of the middle layer is 1.5-2.5 microns;

the substrate 4 is a low-activation steel layered structure and has good neutron irradiation performance.

The present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit and scope of the present invention. The present invention can adopt the prior art for the content which is not described in detail in the present invention.

Claims

1. A first wall with tritium-resistant function for a fusion reactor, comprising a deposit (2), an intermediate layer (3) and a substrate (4), characterized in that: the deposition layer (2) is in direct contact with the plasma (1), and the intermediate layer (3) is located between the deposition layer (2) and the substrate (4).

2. A first wall with tritium-blocking function for a fusion reactor according to claim 1, characterized in that: the deposition layer (2) is a tungsten coating.

3. A first wall with tritium-blocking function for a fusion reactor according to claim 2, characterized in that: the thickness of the tungsten coating is 0.2-3 mm.

4. A first wall with tritium-blocking function for a fusion reactor according to claim 1, characterized in that: the substrate (4) is of a low-activation steel layered structure.

5. A first wall with tritium-blocking function for a fusion reactor according to claim 1, characterized in that: the middle layer (3) is a tritium-resistant coating.

6. A first wall with tritium-blocking function for a fusion reactor according to claim 5, characterized in that: the tritium-resistant coating is a titanium nitride layer.

7. A first wall with tritium-blocking function for a fusion reactor according to claim 6, characterized in that: the thickness of the titanium nitride layer is 1.5-2.5 microns.