A lead-based neutron multiplier suitable for fusion reactor solid blanket

Abstract

The present invention discloses a lead-based neutron multiplier suitable for the solid blanket of a fusion reactor, which adopts a composite sphere design with a three-layer core-shell structure: Pb x M y The core material is a lead-based intermetallic compound with a high melting point and excellent neutron multiplication performance, including but not limited to LaPb3, CePb3, Zr5Pb4, Zr5Pb3, PrPb3, NbPb3, Nd5Pb4, Nd5Pb3, PbS, which plays the role of neutron multiplication; the middle shell is Pb x M y ‑Li2O metal-ceramic composite materials, through the efficient production of tritium by Li2O and fusion neutrons to improve the comprehensive tritium breeding ratio of the blanket, while the metal-ceramic composite materials and Pb x M y The metal interface has a good thermodynamic match, achieving a stable overall core-shell structure; Pb x M y The outer shell is a thin film to ensure the chemical inertness of the spherical shell as a whole. The present invention proposes a neutron multiplier design that is economical and can meet the requirements of tritium proliferation in fusion reactors, and can provide a practical solution for replacing pure beryllium.

Description

Technical Field

[0001] The invention belongs to the field of nuclear fusion science, and in particular relates to a lead-based neutron multiplier suitable for a solid blanket of a fusion reactor. Background Art

[0002] Fusion energy has the advantages of abundant resources and near-zero pollution, making it an ideal energy source for human society in the future. It is one of the most promising fundamental ways to completely solve the energy problem. It has important strategic significance for the sustainable development of my country's economy and society, and is a basic frontier field related to long-term development.

[0003] At present, research on magnetic confinement nuclear fusion based on tokamak devices is relatively extensive and progressing rapidly. The international cooperation project "International Thermonuclear Experimental Reactor" (ITER) has entered the construction stage. As a member of the project, my country plans to build and operate the Chinese Fusion Engineering Test Reactor CFETR in 2030-2040 in the technical route of magnetic confinement nuclear fusion energy development, filling the gap between the International Thermonuclear Experimental Reactor (ITER) and the Fusion Demonstration Reactor (DEMO).

[0004] The basic premise for fusion reactors to operate and generate electricity is that tritium is self-sustaining. Achieving tritium self-sustaining has always been one of the hot issues in the fusion field. 6 The tritium breeder reaction of Li is the main method to produce tritium, namely 6 Li(n,T) nuclear reactions produce tritium. In order to maximize the tritium multiplication rate, a neutron multiplier needs to be added to increase the neutron flux. The neutron multiplier materials currently used in the solid blanket design of fusion reactors include pure beryllium, beryllium-containing or lead-containing materials, among which pure beryllium is selected as the main option due to its optimal neutron multiplication performance. However, due to the disadvantages of beryllium such as high cost, material swelling due to radiation, and strong toxicity, the international community is also actively seeking alternative materials and solutions for beryllium. The main problem faced by high-melting-point lead-based materials as candidate materials to replace beryllium is that the neutron multiplication rate cannot meet the tritium multiplication ratio requirements. The present invention proposes a new lead-based neutron multiplier design, which improves neutron utilization and comprehensive tritium production, and provides a neutron multiplier beryllium alternative for CFETR and future fusion reactors. Summary of the invention

[0005] The purpose of the present invention is to provide a lead-based neutron multiplier suitable for the solid blanket of a fusion reactor, which solves the problems of high cost, strong toxicity and chemical activity of beryllium as a neutron multiplier. In order to improve the tritium multiplication ratio of lead-based materials as neutron multipliers, the technical solution adopted by the present invention is:

[0006] A lead-based neutron multiplier suitable for a fusion reactor solid blanket, which adopts a three-layer core-shell spherical structure, including Pb x M y Center of ball, Pb x My -Li2O metal ceramic interlayer and Pb x M y Shell layer; wherein the Pb x M y The center of the ball is a lead-based intermetallic compound Pb x M y , wherein M is La, Ce, Zr, Pr, Nb, Nd or S, and the values ​​of x and y are determined by M; the Pb x M y -Li2O metal ceramic intermediate layer is Pb x M y -Li2O metal-ceramic composite material; the Pb x M y The outer shell is Pb x M y Film; wherein the Pb x M y The center of the sphere is the neutron multiplication zone, and the Pb x M y -Li2O metal ceramic intermediate layer as an additional tritium producing area; the Pb x M y The outer shell layer is a micrometer-scale thin film layer, which is conducive to the release of tritium in the Li isotope tritium production reaction. x M y The outer shell isolates Li2O from chemical reactions with water and carbon dioxide in the air.

[0007] Furthermore, the Pb x M y -Li2O metal ceramic intermediate layer has the x M y Center of sphere and Pb x M y Pb in the outer shell x M y Good thermodynamic matching between metal interfaces prevents cracking between shell layers caused by thermal stress, forming a structurally stable core-shell spherical structure.

[0008] Furthermore, the Li2O content is selected and optimized through neutronic calculation to increase the tritium production rate.

[0009] The advantages of the present invention compared with the prior art are as follows:

[0010] 1) Currently, neutron multipliers made of beryllium or beryllium-containing materials have the disadvantages of high cost, radiation swelling, strong toxicity, and chemical reaction with water. The lead-based materials used in the present invention have significant advantages in solving the above problems, thus providing an effective solution for neutron multiplier materials that replace beryllium.

[0011] 2) The neutron multiplication rate of traditional solid lead-based materials as neutron multipliers cannot meet the tritium proliferation requirements. The present invention adopts a three-layer core-shell structure design with added Li2O, and realizes the application of lead-based materials by increasing neutron utilization and additional tritium production to comprehensively improve the tritium production rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The present invention is a schematic structural diagram of a lead-based neutron multiplier suitable for a solid blanket of a fusion reactor.

[0013] Among them: 1-Pb x M y Center of sphere, 2-Pb x M y -Li2O metal ceramic intermediate layer, 3-Pb x M y Outer shell layer. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0015] like Figure 1 As shown, the present invention proposes a lead-based neutron multiplier suitable for the solid blanket of a fusion reactor, which adopts a three-layer core-shell spherical structure, including Pb x M y Center of ball, Pb x M y -Li2O metal ceramic interlayer and Pb x M y Shell layer. x M y The sphere center 1 is a neutron multiplication zone and is a lead-based intermetallic compound Pb with a high melting point. x M y , where M is La, Ce, Zr, Pr, Nb, Nd or S, and the values ​​of x and y are determined by M. x M y Including but not limited to LaPb3, CePb3, Zr5Pb4, Zr5Pb3, PrPb3, NbPb3, Nd5Pb4, Nd5Pb3, PbS, which have high melting point characteristics and can exert the excellent neutron multiplication ability of Pb element. x M y -Li2O metal ceramic intermediate layer 2 is the tritium producing area, and Li2O moderates neutrons to further improve6 The tritium production of Li. x M y The outer shell layer 3 is a thin film layer of micrometer scale, which is conducive to the release of tritium in the tritium production reaction of Li isotopes. x M y The outer shell layer 3 isolates Li2O from chemical reactions with components such as water and carbon dioxide in the air.

[0016] The Pb x M y -Li2O metal ceramic intermediate layer 2 contains Pb x M y Li2O-based metal-ceramic composites with the Pb x M y Center 1 and Pb x M y Pb in shell 3 x M y The metal interface has a good thermodynamic match and a structurally stable core-shell structure.

[0017] In terms of composition design, neutronic calculations were carried out on the specific blanket structure, and by adjusting the Li2O and Pb x M y The tritium breeding ratio is optimized by the ratio of , so as to further increase the tritium production rate.

[0018] In the design of fusion reactor blanket, in order to achieve different tritium multiplication ratio requirements, the design is carried out by using the idea of ​​sharing new lead-based neutron multipliers with beryllium-based neutron multipliers, and the corresponding tritium multiplication ratio and cost budget requirements are achieved by adjusting the ratio and layout of the two materials.

[0019] The present invention does not elaborate on the parts that belong to the common technology of those skilled in the art. The above is only a preferred embodiment of the invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A lead-based neutron multiplier suitable for fusion reactor solid blanket, characterized in that: It adopts a three-layer core-shell spherical structure, including Pb x M y Center of ball, Pb x M y -Li2O metal ceramic interlayer and Pb x M y Shell layer; wherein the Pb x M y The center of the ball is a lead-based intermetallic compound Pb x M y , wherein M is La, Ce, Zr, Pr, Nb, Nd or S, and the values ​​of x and y are determined by M; the Pb x M y -Li2O metal ceramic intermediate layer is Pb x M y -Li2O metal-ceramic composite material; the Pb x M y The outer shell is Pb x M y Film; wherein the Pb x M y The center of the sphere is the neutron multiplication zone, and the Pb x M y -Li2O metal ceramic intermediate layer as an additional tritium producing area; the Pb x M y The outer shell layer is a micrometer-scale thin film layer, which is conducive to the release of tritium in the Li isotope tritium production reaction. x M y The outer shell isolates Li2O from chemical reactions with water and carbon dioxide in the air.

2. The lead-based neutron multiplier suitable for fusion reactor solid blanket according to claim 1, characterized in that: The Pb x M y -Li2O metal ceramic intermediate layer has the x M y Center of sphere and Pb x M y Pb in the outer shell x M y Good thermodynamic matching between metal interfaces prevents cracking between shell layers caused by thermal stress and forms a structurally stable core-shell spherical structure.

3. The lead-based neutron multiplier suitable for fusion reactor solid blanket according to claim 1, characterized in that: The Li2O content is selected and optimized through neutronic calculation to increase the tritium production rate.

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