CN108059405A - A kind of nuclear power plant containment shell concrete - Google Patents

Abstract

The invention relates to a nuclear power plant containment concrete, which is composed of the following parts by mass: 130-200 parts of 52.5 or 42.5 cement, 60-120 parts of slag, 50-100 parts of metakaolin, 50-150 parts of boron glass sand, and nickel slag 600‑800 parts, barite 600‑800 parts, limonite 200‑400 parts, ceramsite 100‑300 parts, lead fiber 20‑50 parts, water 130‑160 parts, water reducing agent 4‑6 parts, early 4-6 copies of strong agent. After the concrete has been cured for 28 days, a layer of anti-radiation paint is applied to the inner surface of the concrete. The nuclear power plant containment concrete prepared by the invention has good radiation protection, can well shield α, β, γ rays and neutron rays, and the concrete has good crack resistance, high temperature resistance and durability, and can be used at the same time Solid waste such as nickel slag and glass powder has been eliminated, and the problems of resource waste and environmental pollution have been solved to a certain extent.

Description

Concrete for nuclear power plant containment

technical field

The invention relates to the field of nuclear power plant safety protection, in particular to a nuclear power plant containment concrete.

Background technique

The containment shell is the nuclear reactor containment shell, which is the outermost building of the pressurized water reactor. The main function of the containment shell structure of the nuclear power plant is to completely shield the radioactive material leaked from the reactor pressure vessel in the shell when the reactor is operating abnormally or even out of control. The last barrier of nuclear power safety, so the containment must have extremely high structural safety and durability while taking into account radiation protection capabilities. At present, the containment of nuclear power plants is mainly made of steel containment, but the cost is high, the fire performance is poor, and it is not resistant to acid and alkali corrosion. When damage occurs, brittle fracture is the main type. It is a development trend for concrete containment to replace steel structure containment. The existing concrete containment structure has low durability and poor fire resistance is an important factor restricting its development.

In addition, metallurgical slag (nickel slag, etc.) produced by metallurgical enterprises is rarely used in the construction industry due to stability problems, and most of them are still disposed of in open-air stacks and landfills, which pollutes the environment on the one hand and wastes resources on the other. Glass production enterprises also face the problem of waste glass stacking.

The molecular arrangement of metakaolin is irregular, showing a thermodynamic metastable state, there are a large number of broken chemical bonds, and it has strong pozzolanic activity; and metakaolin requires less water than silica fume, and its effect on concrete reinforcement is similar to that of silica fume, with micro-aggregate filling Effect, can reduce concrete porosity, improve pore structure, increase cement stone compactness, the price is only one tenth of silica fume, and has broad development prospects.

Boron-containing substances have the effect of weakening the penetration strength of neutron flow. As the carrier of boron element, boron glass sand can be added to concrete in the form of fine aggregate to increase the boron content of concrete, and it does not react with other components of concrete. Enhance the radiation resistance of concrete.

Lead has the characteristics of high atomic number and high density, which is of great significance in the field of nuclear radiation protection. Using lead fiber as the lead element carrier can not only play the role of radiation protection, but also effectively enhance the impact resistance of concrete. Ores such as barite and limonite also have a large atomic number and a high apparent density, which can effectively block rays from penetrating concrete.

Ceramsite has the advantages of light weight and high strength. Sintered ceramsite has excellent fire resistance, and adding it to concrete can enhance the fire resistance of concrete. And because the ceramsite is light in weight, low in elastic modulus, good in deformation resistance, and has good shock resistance.

The invention utilizes metakaolin to prepare relatively dense and highly durable concrete, utilizes boron glass sand, barite, limonite, lead fiber, and barium sulfate coating to greatly enhance the radiation protection ability, and adopts sintered ceramsite as the Aggregate controls the bulk density of concrete and enhances the fire resistance of concrete. At the same time, nickel slag is fully utilized to avoid environmental pollution and waste of resources.

Contents of the invention

Technical problem: The technical problem to be solved by the present invention is to provide a kind of containment concrete for nuclear power plants. This invention firstly solves the weaknesses of ordinary containment concrete, such as excessive bulk density, low impact resistance and high temperature resistance, and secondly solves the problems of nickel slag and other solids. Waste resources occupy land and pollute the environment.

Technical solution: The nuclear power plant containment concrete of the present invention is composed of the following parts by mass, 130-200 parts of 52.5 or 42.5 cement, 60-120 parts of slag, 50-100 parts of metakaolin, 50-150 parts of boron glass sand, and 600-200 parts of nickel slag. 800 parts, barite 600-800 parts, limonite 200-400 parts, ceramsite 100-300 parts, lead fiber 20-50 parts, water 130-160 parts, water reducing agent 4-6 parts, early strength agent 4-6 servings.

The metakaolin is processed from kaolin at a high temperature of 800° C., and its activity index is 120%.

The particle diameter of the boron glass sand is less than 2 mm, the main components are SiO ₂ and B ₂ O ₃ , and the boron content is 15%.

The particle size of the nickel slag is less than 5mm, which is water-quenched nickel slag.

The barite BaSO ₄ content is not less than 80%, the bulk density is 3000-3100kg/ ^m3 , the sulfide and sulfuric acid compound of gypsum or pyrite is not more than 7%, and the particle size is 10-25mm.

The limonite Fe ₂ O ₃ content is more than 70%, the impurity content is less than 0.5%, and the particle size is 10-25mm.

The ceramsite is light sintered ceramsite, with a bulk density of ≤700kg/m ³ and a particle size of 5-10mm.

The lead fiber has a diameter of 30-60 μm and a length of 10-50 mm.

The early strength agent is a type I triethanolamine organic early strength agent with a mass fraction ≥ 99.0%.

After the concrete has been cured for 28 days, a layer of anti-radiation paint is applied to the inner surface of the concrete. The anti-radiation paint is a precipitated _BaSO4 organic solvent paint with polyimide or polyoxadiazole as a binder.

Beneficial effects: 1) The use of a large amount of slag can effectively increase the high temperature resistance; 2) Metakaolin molecules present a thermodynamic metastable state, there are a large number of broken chemical bonds, and have strong pozzolanic activity, and metakaolin requires less water than silica fume , while the concrete reinforcement effect is similar to that of silica fume, with micro-aggregate filling effect, which can reduce concrete void ratio, improve pore structure, and increase cement stone density, and the price is only one-tenth of silica fume; 3) boron glass sand As a carrier of boron element, adding fine aggregate to concrete can increase the boron content of concrete, and it does not react with other components of concrete, which can greatly enhance the anti-radiation ability of concrete; 4) lead has a high atomic number and high density. It is of great significance to be used in the field of nuclear radiation protection. Using lead fiber as the carrier of lead element can not only play the role of radiation protection, but also effectively enhance the impact resistance of concrete; Waste resources, effectively avoiding environmental pollution and saving resources; 6) Applying sintered ceramsite to concrete can effectively enhance the fire resistance and earthquake resistance of concrete, improve the durability of concrete, and due to the characteristics of light weight and high strength, it can effectively control the concrete Bulk density; 7) The inner surface of the concrete is coated with a layer of anti-radiation paint, which can effectively shield X-rays and gamma rays, effectively prevent radiation leakage, and enhance the anti-radiation ability of concrete.

Detailed ways

The invention relates to a nuclear power plant containment concrete, which is characterized in that the concrete used is composed of the following parts by mass: 130-200 parts of 52.5 or 42.5 cement, 60-120 parts of slag, 50-100 parts of metakaolin, and 50-150 parts of boron glass sand , 600-800 parts of nickel slag, 600-800 parts of barite, 200-400 parts of limonite, 100-300 parts of ceramsite, 20-50 parts of lead fiber, 130-160 parts of water, 4-6 parts of water reducer parts, 4-6 parts of early strength agent. After the concrete has been cured for 28 days, a layer of anti-radiation paint is applied to the inner surface of the concrete.

The metakaolin is processed from kaolin at a high temperature of 800° C., and its activity index is 120%.

The particle diameter of the boron glass sand is less than 2 mm, the main components are SiO ₂ and B ₂ O ₃ , and the boron content is 15%.

The particle size of the nickel slag is less than 5mm, which is water-quenched nickel slag.

The barite BaSO ₄ content is not less than 80%, the bulk density is 3000-3100kg/ ^m3 , the sulfide and sulfuric acid compound of gypsum or pyrite is not more than 7%, and the particle size is 10-25mm.

The limonite Fe ₂ O ₃ content is more than 70%, the impurity content is less than 0.5%, and the particle size is 10-25mm.

The ceramsite is light sintered ceramsite, with a bulk density of ≤700kg/m ³ and a particle size of 5-10mm.

The lead fiber has a diameter of 30-60 μm and a length of 10-50 mm.

The early strength agent is a type I triethanolamine organic early strength agent with a mass fraction ≥ 99.0%.

The anti-radiation paint is a precipitated _BaSO4 organic solvent paint with polyimide or polyoxadiazole as a binder.

Embodiment one,

The containment concrete of a nuclear power plant is composed of the following parts by mass: 200 parts of PII 42.5 cement, 120 parts of slag, 50 parts of metakaolin, 100 parts of boron glass sand, 700 parts of nickel slag, 800 parts of barite, 200 parts of limonite, and ceramsite 200 parts, 40 parts of lead fiber, 160 parts of water, 4 parts of polycarboxylate superplasticizer, 5 parts of early strength agent. After the concrete was cured for 28 days, a layer of precipitated BaSO ₄ organic solvent radiation-proof coating with polyimide as the binder was coated on the inner surface of the concrete.

Embodiment two,

The containment concrete of a nuclear power plant is composed of the following parts by mass: 140 parts of PII 52.5 cement, 60 parts of slag, 100 parts of metakaolin, 50 parts of boron glass sand, 750 parts of nickel slag, 700 parts of barite, 400 parts of limonite, ceramsite 100 parts, 50 parts of lead fiber, 130 parts of water, 6 parts of polycarboxylate superplasticizer, 4.5 parts of early strength agent. After the concrete was cured for 28 days, a layer of precipitated BaSO ₄ organic solvent anti-radiation coating with polyoxadiazole as the binder was coated on the inner surface of the concrete.

Embodiment three,

The containment concrete of a nuclear power plant is composed of the following parts by mass: 130 parts of PII 42.5 cement, 100 parts of slag, 80 parts of metakaolin, 150 parts of boron glass sand, 600 parts of nickel slag, 600 parts of barite, 300 parts of limonite, ceramsite 300 parts, 20 parts of lead fiber, 140 parts of water, 4.5 parts of polycarboxylate superplasticizer, 6 parts of early strength agent. After the concrete was cured for 28 days, a layer of precipitated BaSO ₄ organic solvent anti-radiation coating with polyoxadiazole as the binder was coated on the inner surface of the concrete.

Embodiment four,

Containment concrete for nuclear power plants consists of the following parts by mass: 160 parts of PII 52.5 cement, 80 parts of slag, 90 parts of metakaolin, 70 parts of boron glass sand, 800 parts of nickel slag, 700 parts of barite, 200 parts of limonite, and ceramsite 200 parts, 50 parts of lead fiber, 150 parts of water, 5 parts of polycarboxylate superplasticizer, 4 parts of early strength agent. After the concrete was cured for 28 days, a layer of precipitated BaSO ₄ organic solvent radiation-proof coating with polyimide as the binder was coated on the inner surface of the concrete.

Concrete performance assessment indicators are in accordance with "Test Methods for Performance of Ordinary Concrete Mixtures" (GB/T50080-2002), "Test Methods for Ordinary Concrete Mechanics" (GB/T 50081-2002) and "Standards for Test Methods for Long-term Performance and Durability of Ordinary Concrete" "(GB/T 50082-2009) implementation. The concrete cured for 28 days was dried from the surface moisture, heated to 600°C, kept at a constant temperature for 2 hours, and then naturally cooled to room temperature for mechanical performance testing.

Table 1 shows the comparison of specific performance indicators between the containment concrete prepared in Examples 1-4 of the present invention and ordinary containment concrete (ie, the comparative example).

The comparative example concrete is composed of the following components by mass: 400 parts of PII52.5 cement, 800 parts of sand, 1200 parts of gravel, 140 parts of water, and 6 parts of polycarboxylate superplasticizer.

Table 1

The strength of the containment concrete prepared by the invention, the remaining ratio of compressive strength after high temperature, the grade of water seepage resistance, the compressive strength and corrosion resistance coefficient of sulfate erosion after 60 dry-wet cycles are all better than those of the comparison sample.

The present invention 1) adopts a large amount of slag, which can effectively increase the high temperature resistance; 2) metakaolin molecules present a thermodynamic metastable state, there are a large number of broken chemical bonds, and have strong pozzolanic activity, and metakaolin requires less water than silica fume, For concrete, the reinforcement effect is similar to that of silica fume, and it has a micro-aggregate filling effect, which can reduce the void ratio of concrete, improve the pore structure, and increase the compactness of cement stones, and the price is only one tenth of silica fume; 3) boron glass sand as The carrier of boron element can be added to concrete in the form of fine aggregate to increase the boron content of concrete, and it does not react with other components of concrete, which can greatly enhance the anti-radiation ability of concrete; 4) lead has the characteristics of high atomic number and high density It is of great significance to be used in the field of nuclear radiation protection. Using lead fiber as the lead element carrier can not only play the role of radiation protection, but also effectively enhance the impact resistance of concrete; 5) Utilize nickel slag in concrete and make full use of solid waste resources, effectively avoiding environmental pollution and saving resources; 6) Applying sintered ceramsite to concrete can effectively enhance the fire resistance and earthquake resistance of concrete, improve the durability of concrete, and due to the characteristics of light weight and high strength, it can effectively control the concrete density ; 7) The inner surface of the concrete is coated with a layer of anti-radiation paint, which can effectively shield X-rays and γ-rays, effectively prevent radiation leakage, and enhance the anti-radiation ability of concrete.

The technical means disclosed in the solutions of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for those skilled in the art, some improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims (10)

1. A nuclear power plant containment concrete is characterized in that used concrete is made up of following mass parts, 52.5 or 42.5 cement 130-200 parts, 60-120 parts of slag, Metakaolin 50-100 parts, 50-150 parts of boron glass sand, 600-800 parts of nickel slag, Barite 600-800 parts, Limonite 200-400 parts, Ceramsite 100-300 parts, 20-50 parts of lead fiber, 130-160 parts of water, 4-6 parts of water reducing agent, 4-6 parts of early strength agent. 2. A nuclear power plant containment concrete according to claim 1, characterized in that the metakaolin is processed from kaolin at a high temperature of 800°C, and its activity index is 120%. 3. A nuclear power plant containment concrete according to claim 1, characterized in that the particle size of the boron glass sand is <2 mm, the main components are SiO ₂ and B ₂ O ₃ , and the boron content is 15% by mass. 4. A nuclear power plant containment concrete according to claim 1, characterized in that the nickel slag has a particle size of less than 5mm and is water-quenched nickel slag. 5. A nuclear power plant containment concrete according to claim 1, characterized in that the barite BaSO ₄ content is not less than 80%, the bulk density is 3000-3100kg/m ³ , and the sulfide containing gypsum or pyrite Chemicals and sulfuric acid compounds do not exceed 7%, and the particle size is 10-25mm. 6 . A nuclear power plant containment concrete according to claim 1 , characterized in that the limonite Fe ₂ O ₃ content is ≥70%, the impurity content is <0.5%, and the particle size is 10-25mm. 7. A nuclear power plant containment concrete according to claim 1, characterized in that the ceramsite is light sintered ceramsite, with a bulk density of ≤700kg/m ³ and a particle size of 5-10mm. 8. A nuclear power plant containment concrete according to claim 1, characterized in that the diameter of the lead fiber is 30-60 μm, and the length is between 10-50 mm. 9. A nuclear power plant containment concrete according to claim 1, characterized in that the accelerator is a type I triethanolamine organic accelerator, with a mass fraction ≥ 99.0%. 10. A kind of nuclear power plant containment concrete according to claim 1, it is characterized in that after 28 days of this concrete maintenance, a layer of anti-radiation coating is coated on the inner surface of the concrete; the anti-radiation coating is made of polyimide or polyimide Oxadiazole as binder for precipitated BaSO ₄ organic solvent coatings.