Resin-based tungsten-boron shielding material, shielding body and application

Abstract

The invention discloses a resin-based tungsten-boron shielding material, a shielding body and application. The resin-based tungsten-boron shielding material comprises the following raw materials in parts by weight: 10-20 parts of epoxy resin, 4-5 parts of a curing agent, 70-83 parts of tungsten and 3-5 parts of irradiated boron tungstate. The resin-based tungsten-boron shielding material can shield composite radiation of any combination of neutrons, photons, electrons and charged particles and reduce secondary radiation, has excellent comprehensive shielding performance, and has the advantages of being thin in thickness, small in size, light in weight, good in stability, resistant to radiation, resistant to high temperature and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of radiation shielding materials, and in particular relates to a resin-based tungsten-boron shielding material and a shielding body and application thereof. Background Art

[0002] Nuclear facilities and radiation devices will generate mixed radiation of various types such as neutrons, photons, electrons or charged particles during operation, or the radiation generated will interact with the shield to produce secondary radiation, such as bremsstrahlung, gamma rays of (n,γ) reactions, neutrons of (α,n) reactions, etc. Among them, neutron radiation and gamma radiation have strong penetrating power, posing a great threat to human life safety, the environment, and instruments and equipment. Therefore, effective comprehensive shielding and protection of nuclear facilities and radiation devices is a necessary means to use nuclear energy to better serve mankind.

[0003] At present, shielding materials include traditional shielding materials such as concrete, steel, lead, and lead-boron polyethylene materials. Traditional shielding materials do not have comprehensive shielding performance and can only meet the needs of medium- and low-level radiation sources or medium- and low-neutron single radiation (neutron dose rate on the radiation source surface is less than 100μSv / h) environments, but cannot meet the needs of medium- and high-level radiation sources (radiation level on the radiation source surface is as high as 1000Gy / h or above) or strong neutron single radiation or mixed radiation (neutron dose rate on the radiation source surface is greater than 100μSv / h or the radiation accounts for more than 10% of the total radiation) environments.

[0004] In addition, the shielding body made of traditional shielding materials has the disadvantages of large thickness, large volume and high weight. The comprehensive shielding performance of lead-boron polyethylene material is better than that of traditional shielding materials, but the density of this material is relatively low (density is 3.4g / cm 3 About), for medium and high radiation sources or high-intensity neutron single radiation or mixed radiation environment, the shielding body thickness, volume and weight are still relatively large, and its matrix is ​​polyethylene, the material has a low melting point (100℃-110℃), poor high temperature resistance, low radiation resistance, and usually deformation, softening, embrittlement and decomposition and fracture problems will occur within a short period of service. Summary of the invention

[0005] The purpose of the present invention is to solve the problems that existing shielding materials cannot simultaneously meet the requirements of comprehensive shielding performance, and the shielding body has large thickness and volume under the same shielding effect, and is not resistant to radiation and high temperature; the present invention proposes a resin-based tungsten-boron shielding material, shielding body and application that solve the above technical problems.

[0006] The technical solution of the present invention:

[0007] A resin-based tungsten-boron shielding material comprises the following raw materials in parts by weight:

[0008]

[0009] The irradiated boron tungsten is boron tungsten that has been irradiated with 50-200 kGy;

[0010] The content of hydrogen in the epoxy resin is not less than 10 wt %.

[0011] The density of the resin-based tungsten-boron shielding material is in the range of 4.0 to 6.0 g / cm 3 .

[0012] The epoxy resin is selected from at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0013] The curing agent is selected from aliphatic amine curing agents; the aliphatic amine curing agent is selected from at least one of DEH2450, DEH2480, and DEH2919.

[0014] The tungsten is selected from at least one of elemental tungsten and a tungsten-containing compound; preferably, the tungsten-containing compound is organic tungsten;

[0015] And / or, the irradiated tungsten boride is tungsten boride irradiated by electron beam or gamma ray.

[0016] The content of tungsten element in the tungsten-containing compound is not less than 10wt%;

[0017] And / or, the ratio of the abundance of tungsten element W-182 to the abundance of tungsten element W-183 in the resin-based tungsten-boron shielding material is 1:(3.0-5.7).

[0018] The mass ratio of the abundance of B-10 to the abundance of B-11 in the boron element in the boron-containing compound is 1:(0.82-5.7);

[0019] Preferably, the mass ratio of the abundance of B-10 to the abundance of B-11 in the boron element is 1:(3.0-5.7), or the mass ratio of the abundance of B-10 to the abundance of B-11 in the boron element is 1:(0.82-4.0).

[0020] The resin-based tungsten-boron shielding body is prepared from the above-mentioned resin-based tungsten-boron shielding material.

[0021] The resistant temperature of the resin-based tungsten-boron shield is not less than 130°C;

[0022] and / or, the tensile strength of the resin-based tungsten-boron shield is not less than 50 MPa;

[0023] And / or, the bending strength of the resin-based tungsten-boron shield is not less than 85 MPa.

[0024] The resin-based tungsten-boron shield is used in nuclear facilities and radiation devices.

[0025] The nuclear facilities and radiation devices mentioned above include nuclear fuel manufacturing plants, nuclear reactors, research reactors, nuclear power plants, spent fuel storage facilities, nuclear fuel enrichment plants or reprocessing facilities, radioactive waste treatment and disposal facilities, radiation generators, radioactive devices and facilities of radioactive sources, etc.

[0026] The beneficial effects of the present invention are:

[0027] 1. A resin-based tungsten-boron shielding material of the present invention, through the combination of raw materials and their weight ratio, makes the shielding body prepared by the material have excellent comprehensive shielding performance, and has the performance of thin thickness, small volume, light weight, radiation resistance and high temperature resistance. Specifically, the addition of tungsten raw materials (tungsten and irradiated tungsten boron) with high-energy neutron and fast neutron slowing effect, excellent photon shielding performance and large mass density greatly improves the density and shielding performance of the shielding material, so that under the same shielding performance, the shielding body has a smaller volume and thinner thickness. The hydrogen element of the epoxy resin in the material further slows down the neutrons, and has good high temperature resistance and radiation resistance. Boron efficiently absorbs the slowed neutrons, thereby greatly reducing the neutron and photon radiation intensity and other radiation with weaker penetration. Therefore, the shielding material has excellent comprehensive shielding performance and can serve in complex radiation environments such as different intensity radiation environments, especially strong neutron radiation and mixed radiation containing strong neutrons. Moreover, the irradiated boron tungsten is produced by boron tungsten being irradiated by electron beam and gamma ray. The RC free radical, RCO free radical and H free radical produced by the electron beam and gamma ray in the irradiated boron tungsten can participate in the coordination of W and B in W2B and form chemical bonds. After irradiation treatment, the stability of the sample can be increased, and then the comprehensive shielding performance can be improved in combination with W.

[0028] The shielding mechanism of this shielding material is: fast neutrons are slowed down by tungsten with a high inelastic scattering cross section, and the slowed down medium and low energy neutrons are elastically scattered with light nuclear elements such as hydrogen and carbon, and the energy of fast neutrons is further reduced, slowed down into thermal neutrons, and then the thermal neutrons are absorbed by boron with a large absorption cross section. This series of processes can not only efficiently slow down and absorb neutrons, but also greatly reduce the secondary radiation generated by the reaction of neutrons and shielding materials due to the significant reduction in fast neutron injection and total neutron intensity. At the same time, tungsten can effectively shield the gamma rays directly radiated by fission and the secondary gamma rays generated by neutrons and shielding materials, so that this material can shield neutrons, photons, electrons and charged particles in any combination of comprehensive shielding.

[0029] 2. This shielding material can adjust the material density and shielding performance by adjusting the tungsten raw material content to adapt to low-radiation, medium- and high-radiation radiation environments, as well as complex radiation environments such as strong neutron radiation in medium- and high-radiation environments and mixed radiation containing strong neutrons.

[0030] 3. This shielding material can effectively regulate and control the abundance of B-10, a boron isotope with a large neutron absorption cross section, and the abundance of W-183, a tungsten element with a large neutron slowing effect, so that when applied to different engineering application scenarios, the shielding material can achieve the best shielding performance and comprehensive shielding properties for neutrons. DETAILED DESCRIPTION

[0031] Example 1

[0032] This embodiment provides a resin-based tungsten-boron shielding material, which includes the following raw materials in weight ratio:

[0033]

[0034] The epoxy resin is bisphenol A epoxy resin (CAS: 25085-99-8) and bisphenol F epoxy resin (CAS number: 620-92-8) in a mass ratio of 4:1; the curing agent is DEH2450 and DEH2919 in a mass ratio of 1:4; the tungsten is single tungsten powder with a particle size of 30 meshes; the irradiated boron tungsten is tungsten boron irradiated with 50 kGy, the abundance ratio of B-10 in the boron element to that of B-11 is 1:4, the abundance ratio of W-182 in the tungsten element to that of W-183 in the tungsten element is 1:4, and the density of the shielding material is 5.7 g / cm 3 .

[0035] The preparation process steps of a resin-based tungsten-boron shielding material are as follows:

[0036] (1) Preparation of epoxy resin: bisphenol A epoxy resin and bisphenol F epoxy resin were added into a reaction kettle in proportion, and mixed evenly by mechanical stirring at a stirring speed of 800 r / min for 20 min to obtain epoxy resin, which was an opaque viscous liquid;

[0037] (2) Preparation of curing agent: Add curing agent DEH2450 and curing agent DEH2919 into a reaction kettle in proportion, mix them evenly with mechanical stirring at a stirring speed of 800 r / min for 20 min to obtain a curing agent, which is a brown to brown liquid with an ammonia smell;

[0038] (3) Preparation of filler: weigh the irradiated boron tungsten and metal tungsten powder in proportion, mix them evenly to obtain a filler which is a powdery solid;

[0039] (4) Mixing: First, add the curing agent to the epoxy resin and stir evenly for 8 minutes, then add the filler and stir for 15 minutes. The total mixing and stirring time is controlled within 25 minutes to obtain a mixed material;

[0040] (5) Casting: The mixed material is injected into the mold cavity and solidified to obtain a sample block.

[0041] Example 2

[0042] The present embodiment provides a resin-based tungsten-boron shielding material, including the following raw materials in weight ratio:

[0043]

[0044] The ratio of the abundance of B-10 in the boron element to the abundance of B-11 is 1:5.5, and the ratio of the abundance of W-182 in the tungsten element to the abundance of W-183 in the tungsten element is 1:5.5. Boron tungsten is tungsten boron after 100kGy irradiation. The density of the obtained resin-based tungsten-boron shielding material is 4.0g / cm 3 .

[0045] The other conditions are exactly the same as those in Example 1.

[0046] Example 3

[0047] The present embodiment provides a resin-based tungsten-boron shielding material, including the following raw materials in weight ratio:

[0048]

[0049]

[0050] The ratio of the abundance of B-10 in the boron element to the abundance of B-11 is 1:0.9, and the ratio of the abundance of W-182 in the tungsten element to the abundance of W-183 in the tungsten element is 1:3. Boron tungsten is tungsten boron after irradiation with 200kGy. The density of the obtained resin-based tungsten-boron shielding material is 6.0g / cm 3 .

[0051] Comparative Example 1

[0052] The shielding material provided in this comparative example is a single carbon steel material with a density of 7.8 g / cm 3 .

[0053] Comparative Example 2

[0054] The shielding material provided in this comparative example is a lead-boron polyethylene material. The density of the lead-boron polyethylene material is 3.4 g / cm 3 The lead content is 77% by mass, the boron content is 1% by mass, and the hydrogen content is 3.2% by mass.

[0055] Experimental Example 1

[0056] The shielding performance of the resin-based tungsten boron of Examples 1-3, the carbon steel of Comparative Example 1, and the lead boron polyethylene of Comparative Example 2 were compared using spent fuel assemblies with a burnup depth of more than 30,000 tU / MWd. Under the premise of achieving the same shielding effect, the required shielding thickness is shown in Table 1 below.

[0057] Table 1 Comparison of shielding performance of samples

[0058] Shielding Materials Shielding thickness (cm) Resin-based tungsten boron of Examples 1 to 3 30～40 Carbon steel of comparative example 1 50 Lead boron polyethylene of comparative example 2 45

[0059] From the comparison between the embodiment and comparative examples 1-2 in Table 1, it can be seen that in the radiation environment of the high-radiation medium-photon composite field, the shielding material of the present invention can be used to reduce the thickness by more than 10% and even by about 40% relative to the conventional metal shielding material in comparative examples 1 and 2, and the performance is very significant.

[0060] Experimental Example 2

[0061] The resin-based tungsten-boron shielding material of Example 1 of the present invention is used to prepare a composite layer (from the inside to the outside: 5 cm carbon steel + 20 cm resin-based tungsten-boron shielding body + 5 cm carbon steel) with the same shielding performance as the original design of the high-level radioactive liquid waste glass solidification body loader (i.e., from the inside to the outside: 3 cm carbon steel + 10 cm lead + 3 cm carbon steel + 16 cm polyethylene + 5 cm carbon steel); the total shielding thickness (cm) and weight (t) are compared, and the results are shown in Table 2.

[0062] The carbon steel used in the original design of the high-level waste glass solidification body loader is the carbon steel material in Comparative Example 1. The polyethylene used in the original design of the high-level waste glass solidification body loader is a single polyethylene material with a density of 0.9 g / cm 3 The lead used in the original design of the high-level waste vitrified body loader was a single lead material with a density of 11.34g / cm 3 .

[0063] Table 2 Comparison of large loader solutions

[0064]

[0065] It can be seen from Table 2 that for a loader with a complex structure used in a high radiation environment, the shielding material of the embodiment of the present invention can reduce the thickness by about 20% and the weight by about 35% under the same shielding performance compared with the shielding material of conventional design.

[0066] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A resin-based tungsten-boron shielding material, characterized in that: Contains the following raw materials in proportion by weight: The irradiated boron tungsten is boron tungsten that has been irradiated with 50-200 kGy; The content of hydrogen in the epoxy resin is not less than 10 wt %.

2. The resin-based tungsten-boron shielding material according to claim 1, characterized in that: The density of the resin-based tungsten-boron shielding material is 4.0 g / cm 3 ~6.0g / cm 3 .

3. The resin-based tungsten-boron shielding material according to claim 1 or 2, characterized in that: The raw material of the epoxy resin is selected from at least one of bisphenol A epoxy resin and bisphenol F epoxy resin; And / or, the curing agent is selected from aliphatic amine curing agents; preferably at least one of DEH2450, DEH2480, and DEH2919; And / or, the tungsten is selected from at least one of elemental tungsten and a tungsten-containing compound; preferably, the tungsten-containing compound is organic tungsten; And / or, the irradiated tungsten boride is tungsten boride irradiated by electron beam or gamma ray.

4. The resin-based tungsten-boron shielding material according to claim 3, characterized in that: The content of tungsten element in the tungsten-containing compound is not less than 10wt%; And / or, the ratio of the abundance of tungsten element W-182 to the abundance of tungsten element W-183 in the resin-based tungsten-boron shielding material is 1:(5.7-3.0).

5. The resin-based tungsten-boron shielding material according to any one of claims 1 to 4, characterized in that: The ratio of the abundance of B-10 to the abundance of B-11 in the boron element in the irradiated tungsten boride is 1:(0.82-5.7).

6. The resin-based tungsten-boron shielding material according to claim 5, characterized in that: The ratio of the abundance of B-10 to the abundance of B-11 in the boron element is 1:(3.0-5.7); Or, the ratio of the abundance of B-10 to the abundance of B-11 in the boron element is 1:(0.82-4.0).

7. A resin-based tungsten-boron shield, characterized in that: The invention is prepared from the resin-based tungsten-boron shielding material described in any one of claims 1 to 6.

8. The resin-based tungsten-boron shield according to claim 7, characterized in that: The resistant temperature of the resin-based tungsten-boron shield is not less than 130°C; and / or, the tensile strength of the resin-based tungsten-boron shield is not less than 50 MPa; And / or, the bending strength of the resin-based tungsten-boron shield is not less than 85 MPa.

9. Use of the resin-based tungsten-boron shielding body according to claim 7 or 8 in nuclear facilities and radiation devices.

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