Hydrogen storage material and nuclear facility

Abstract

To suppress oxidation reactions under normal conditions for contact safety and to ensure resistance against vapor.SOLUTION: A hydrogen storage material 1 includes: a first coating layer 2 having oxidation resistance covering a surface; and a second coating layer 3 having water repellency covering the first coating layer 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to hydrogen storage materials and nuclear facilities. [Background technology]

[0002] For example, Patent Document 1 describes the installation of a hydrogen adsorption device containing a hydrogen storage material that adsorbs hydrogen gas inside a reactor containment vessel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-034395 Summary of the Invention [Problem to be solved by the invention]

[0004] Hydrogen storage materials are used to reduce hydrogen that may be generated in the event of a severe accident at nuclear facilities through a passive process that does not involve oxygen or chemical reactions. However, when using hydrogen storage materials, it is desirable to ensure contact safety by suppressing oxidation reactions under normal conditions, and to ensure resistance to steam that may be generated in the event of a severe accident.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a hydrogen storage material and nuclear equipment that can suppress oxidation reactions under normal conditions, ensure contact safety, and ensure resistance to steam. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a hydrogen storage material according to one embodiment of the present disclosure includes a first coating layer that covers the surface and has oxidation resistance, and a second coating layer that covers the first coating layer and has water repellency.

[0007] In order to achieve the above object, in a nuclear facility according to one aspect of the present disclosure, a hydrogen storage material is disposed inside a reactor containment vessel. [Effects of the Invention]

[0008] The present disclosure can suppress oxidation reactions under normal circumstances to ensure contact safety and steam resistance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view of a hydrogen storage material according to an embodiment. [Figure 2] FIG. 2 is a diagram showing the outer shape of the hydrogen storage material according to the embodiment. [Figure 3] FIG. 3 is a diagram showing the outer shape of another example of the hydrogen storage material according to the embodiment. [Figure 4] FIG. 4 is a diagram showing the outer shape of another example of the hydrogen storage material according to the embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the accommodation of the hydrogen storage material according to the embodiment. [Figure 6] FIG. 6 is a schematic diagram of a nuclear facility to which the hydrogen storage material of the embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially the same.

[0011] FIG. 1 is a schematic cross-sectional view of a hydrogen storage material according to an embodiment.

[0012] The hydrogen storage material 1 of the embodiment is a pure metal or alloy that absorbs hydrogen in the atmosphere. Specifically, the hydrogen storage material 1 can be titanium-based, magnesium-based, yttrium-based, or vanadium-based. The hydrogen storage material 1 preferably has a hydrogen storage capacity in which the ratio (H / M) of hydrogen atoms to the total amount of metal atoms constituting the alloy is as large as possible. Furthermore, the hydrogen storage material 1 is preferably a material in which, in a PCT characteristic curve that represents the relationship between hydrogen pressure P, hydrogen storage capacity C, and atmospheric temperature T, a plateau region, where the gradient of hydrogen pressure P relative to hydrogen storage capacity C is small, appears at a lower hydrogen pressure P under conditions where the atmospheric temperature T is as high as possible.

[0013] As shown in FIG. 1, the hydrogen storage material 1 includes a first coating layer 2 and a second coating layer 3.

[0014] The first coating layer 2 covers the surface of the hydrogen storage material 1. The first coating layer 2 is made of an oxidation-resistant material to suppress the oxidation reaction of the hydrogen storage material 1. Specifically, a palladium-based material can be used for the first coating layer 2. Furthermore, the first coating layer 2 is preferably thick enough to provide sufficient oxidation resistance, yet thin enough not to inhibit the hydrogen storage function of the hydrogen storage material 1. The first coating layer 2 preferably has sufficient hydrogen permeability relative to its thickness so as not to inhibit the hydrogen storage function of the hydrogen storage material 1.

[0015] The second coating layer 3 covers the first coating layer 2. The second coating layer 3 is made of a water-repellent material to prevent water droplets from condensing in the atmosphere from covering the hydrogen storage material 1 and inhibiting hydrogen absorption. Specifically, the second coating layer 3 is made of the same material as the first coating layer 2, but is surface-treated to be water-repellent. Alternatively, the second coating layer 3 is made of a water-repellent material such as zeolite, and in the case of Si-Al-O-based materials, a Si-rich material is preferred. The second coating layer 3 preferably does not contain resin to avoid deterioration in an atmosphere with high radiation levels. Furthermore, the second coating layer 3 is preferably thick enough to provide sufficient water repellency, but thin enough to ensure the hydrogen storage function of the hydrogen storage material 1 and the oxidation resistance function of the first coating layer 2 without interfering with them. The second coating layer 3 preferably has sufficient hydrogen permeability relative to its thickness so as not to interfere with the hydrogen storage function of the hydrogen storage material 1 and the oxidation resistance function of the first coating layer 2.

[0016] 1 is shown as having a circular cross section, it may also be rectangular, and is not limited thereto. The hydrogen storage material 1 may have various outer shapes, such as a spherical shape, a cylindrical shape, a rectangular parallelepiped, a plate shape, or a cylindrical shape. When the hydrogen storage material 1 has inner and outer surfaces, such as a cylindrical shape, a first coating layer 2 and a second coating layer 3 are provided on the outer and inner surfaces of the hydrogen storage material 1.

[0017] FIG. 2 is a diagram showing the outer shape of the hydrogen storage material according to the embodiment.

[0018] The hydrogen storage material 1 is preferably formed in a honeycomb shape, as shown in Figure 2. That is, the hydrogen storage material 1 is composed of multiple hexagonal cylinders connected together. By forming the hydrogen storage material 1 in a honeycomb shape, a larger contact area with the atmosphere can be ensured compared to a block structure, and the hydrogen storage function can be improved. Furthermore, by forming the hydrogen storage material 1 in a honeycomb shape, heat dissipation properties can be improved and the hydrogen storage function can be ensured.

[0019] FIG. 3 is a diagram showing the outer shape of another example of the hydrogen storage material according to the embodiment.

[0020] As shown in Fig. 3, the hydrogen storage material 1 preferably has a plurality of fins 5. By having the fins 5, the hydrogen storage material 1 can ensure a larger contact area with the atmosphere compared to a block structure, thereby improving the hydrogen storage function. Furthermore, by having the fins 5, the hydrogen storage material 1 can improve heat dissipation and ensure the hydrogen storage function.

[0021] Fig. 4 is a diagram showing the outer shape of another example of the hydrogen storage material according to the embodiment, and Fig. 5 is a diagram showing an example of the accommodation of the hydrogen storage material according to the embodiment.

[0022] The hydrogen storage material 1 is preferably formed in a granular form such as pellets as shown in Fig. 4. The granular form is not limited to the form shown in Fig. 4. By forming the hydrogen storage material 1 in a granular form, a larger contact area with the atmosphere can be ensured compared to a single block configuration, and the hydrogen storage function can be improved.

[0023] When the hydrogen storage material 1 is formed into granules, it is housed in a container 6 as shown in Fig. 5. The container 6 is formed of a container, such as a basket, having holes that allow gas to pass through it. It is preferable that the container 6 has a sufficient opening area for the holes to ensure the hydrogen storage function of the hydrogen storage material 1.

[0024] FIG. 6 is a schematic diagram of a nuclear facility to which the hydrogen storage material of the embodiment is applied.

[0025] The above-described hydrogen storage material 1 is applied to nuclear power facilities.

[0026] FIG. 6 shows a reactor containment vessel 11 in a nuclear facility. The reactor containment vessel 11 is erected on solid ground 81, such as bedrock. The reactor containment vessel 11 is divided into multiple compartments, such as an upper compartment 83 and a steam generator loop chamber 84, using reinforced concrete or the like. A cylindrical structure 100 that defines the steam generator loop chamber 84 is formed in the center of the reactor containment vessel 11, and the reactor vessel 41 is suspended and supported by this concrete-containing structure 100. In the reactor containment vessel 11, a steam generator 13 is disposed in the steam generator loop chamber 84, and the steam generator 13 is connected to the reactor vessel 41 by cooling water piping 14 and 15. Furthermore, a cavity chamber 150 is defined within the reactor containment vessel 11 by the structure 100, located below the reactor vessel 41. The cavity chamber 150 is a section that receives molten core material in the event of a severe accident in which the molten core material flows out of the reactor vessel 41. The containment vessel 11 is provided with a refueling water pit 88. The refueling water pit 88 is connected to a reactor cooling path (cooling water supply system) 89 that supplies cooling water to the pressurized water reactor 12 to cool it in an emergency, and a containment vessel cooling path (cooling water supply system) 90 that sprays cooling water into the containment vessel 11 to cool it. The cooling water sprayed into the containment vessel 11 is stored in the cavity chamber 150 from the steam generator loop chamber 84 via a drain line (not shown) provided in the structure 100. Although not shown, the containment vessel 11 is provided with an external injection path for fire extinguishing water or the like that supplies cooling water to the cavity chamber 150.

[0027] In such a nuclear facility, the hydrogen storage material 1 is placed inside the reactor containment vessel 11. The hydrogen storage material 1 is placed inside the reactor containment vessel 11, above the cavity chamber 150. Specifically, the hydrogen storage material 1 is installed in the upper compartment 83 of the reactor containment vessel 11. A plurality of hydrogen storage materials 1 are placed in the upper compartment 83 of the reactor containment vessel 11, along the inner shape of the dome-shaped ceiling portion 11A that closes the top of the cylindrical body portion 11B. Although not shown in the figure, when the reactor containment vessels 11 are configured in multiple layers, the hydrogen storage material 1 may be placed between each of the reactor containment vessels 11.

[0028] In this way, the hydrogen storage material 1 of the embodiment is installed inside the reactor containment vessel 11. When the hydrogen storage material 1 is configured as a block or honeycomb shape or has fins 5, it is fixed with bolts or the like to a support material (not shown) fixed to the inner wall or floor of the reactor containment vessel 11, and is installed by being attached to the wall or hung. When the hydrogen storage material 1 is configured in a granular form, the container 6 is fixed with bolts or the like to a support material (not shown) fixed to the inner wall or floor of the reactor containment vessel 11, and is installed by being attached to the wall or hung.

[0029] The hydrogen storage material 1 of the embodiment can reduce hydrogen that may be generated during a severe accident at a nuclear facility through a static process that does not use oxygen or chemical reactions. By reducing hydrogen through a static process, an ignition source is not required, ensuring the safety of the nuclear facility. Moreover, the first coating layer 2 of the hydrogen storage material 1 can suppress oxidation reactions during normal operation (normal operation without accidents), ensuring contact safety. Furthermore, the second coating layer 3 of the hydrogen storage material 1 can ensure resistance to steam that may be generated during a severe accident.

[0030] In the nuclear facility, hydrogen explosions can be avoided and safety can be ensured because hydrogen in the atmosphere is reduced by installing the hydrogen storage material 1 inside the reactor containment vessel 11. Moreover, in the nuclear facility, hydrogen in the atmosphere can be efficiently reduced in areas where the hydrogen concentration can be high by arranging the hydrogen storage material 1 above the cavity chamber 150 inside the reactor containment vessel 11.

[0031] The present disclosure includes the following inventions. [Invention 1] a first coating layer having oxidation resistance covering the surface; a second coating layer having water repellency and covering the first coating layer; A hydrogen storage material comprising: [Invention 2] Formed in a honeycomb shape, The hydrogen storage material according to Invention 1. [Invention 3] formed into granules, The hydrogen storage material according to Invention 1. [Invention 4] having a plurality of fins; The hydrogen storage material according to Invention 1. [Invention 5] A nuclear facility in which the hydrogen storage material according to any one of Inventions 1 to 4 is placed inside a reactor containment vessel. [Invention 6] The hydrogen storage material is disposed inside the reactor containment vessel and above the cavity chamber. A nuclear facility according to invention 5. [Explanation of symbols]

[0032] 1. Hydrogen storage materials 2. First coating layer 3 Second coating layer 5 Fins 11 Reactor containment vessel 150 Cavity Room

Claims

1. a first coating layer having oxidation resistance covering the surface; a second coating layer having water repellency and covering the first coating layer; A hydrogen storage material comprising:

2. Formed in a honeycomb shape, The hydrogen storage material according to claim 1 .

3. It is formed into granules, The hydrogen storage material according to claim 1 .

4. having a plurality of fins; The hydrogen storage material according to claim 1 .

5. A nuclear facility, wherein the hydrogen storage material according to any one of claims 1 to 4 is disposed inside a reactor containment vessel.

6. The hydrogen storage material is disposed inside the reactor containment vessel and above the cavity chamber. The nuclear facility according to claim 5.

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