JP7373438B2 - neutron shield - Google Patents
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- JP7373438B2 JP7373438B2 JP2020044764A JP2020044764A JP7373438B2 JP 7373438 B2 JP7373438 B2 JP 7373438B2 JP 2020044764 A JP2020044764 A JP 2020044764A JP 2020044764 A JP2020044764 A JP 2020044764A JP 7373438 B2 JP7373438 B2 JP 7373438B2
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- 239000000843 powder Substances 0.000 claims description 66
- 239000002893 slag Substances 0.000 claims description 44
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 33
- 229910052796 boron Inorganic materials 0.000 claims description 33
- 239000010881 fly ash Substances 0.000 claims description 32
- 150000001875 compounds Chemical class 0.000 claims description 30
- 229910021540 colemanite Inorganic materials 0.000 claims description 21
- -1 alkali metal salt Chemical class 0.000 claims description 17
- 239000002245 particle Substances 0.000 claims description 17
- 229910052783 alkali metal Inorganic materials 0.000 claims description 15
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims description 12
- 235000012239 silicon dioxide Nutrition 0.000 claims description 12
- 230000001186 cumulative effect Effects 0.000 claims description 10
- 239000000203 mixture Substances 0.000 description 32
- 150000001639 boron compounds Chemical class 0.000 description 26
- 239000000463 material Substances 0.000 description 26
- 239000004568 cement Substances 0.000 description 25
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 10
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 10
- 238000002834 transmittance Methods 0.000 description 8
- 239000000047 product Substances 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 239000004115 Sodium Silicate Substances 0.000 description 6
- 238000011161 development Methods 0.000 description 6
- 230000005764 inhibitory process Effects 0.000 description 6
- 229910052911 sodium silicate Inorganic materials 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 230000005540 biological transmission Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000004570 mortar (masonry) Substances 0.000 description 5
- 235000019353 potassium silicate Nutrition 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 229920000876 geopolymer Polymers 0.000 description 4
- 238000010298 pulverizing process Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000002956 ash Substances 0.000 description 2
- 239000011400 blast furnace cement Substances 0.000 description 2
- 210000000988 bone and bone Anatomy 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000003245 coal Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002480 mineral oil Substances 0.000 description 2
- 235000010446 mineral oil Nutrition 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 239000008399 tap water Substances 0.000 description 2
- 235000020679 tap water Nutrition 0.000 description 2
- 239000002912 waste gas Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 239000004111 Potassium silicate Substances 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- YKTSYUJCYHOUJP-UHFFFAOYSA-N [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] Chemical compound [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] YKTSYUJCYHOUJP-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000011083 cement mortar Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000012669 compression test Methods 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 230000037427 ion transport Effects 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- PAZHGORSDKKUPI-UHFFFAOYSA-N lithium metasilicate Chemical compound [Li+].[Li+].[O-][Si]([O-])=O PAZHGORSDKKUPI-UHFFFAOYSA-N 0.000 description 1
- 229910052912 lithium silicate Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000004482 other powder Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- NNHHDJVEYQHLHG-UHFFFAOYSA-N potassium silicate Chemical compound [K+].[K+].[O-][Si]([O-])=O NNHHDJVEYQHLHG-UHFFFAOYSA-N 0.000 description 1
- 229910052913 potassium silicate Inorganic materials 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000008213 purified water Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000010801 sewage sludge Substances 0.000 description 1
- 229910021487 silica fume Inorganic materials 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000004328 sodium tetraborate Substances 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Curing Cements, Concrete, And Artificial Stone (AREA)
Description
本開示は、中性子遮蔽体に関する。 The present disclosure relates to neutron shields.
従来、原子力施設、放射線発生装置を収納した施設等の構造物では、内部で発生した放射線の外部への放出を防止するため、コンクリートなどで構成された厚い遮蔽体で被覆されている。
なかでも、中性子線については、エネルギー量により挙動が変わることから、効果的な遮蔽が困難であり、例えば、コンクリートで構成された遮蔽体は十分な遮蔽性を確保するためには相当の厚みが必要であった。
ホウ素は中性子を吸収する元素として知られており、例えば、コレマナイト、ヒルガダイト等のホウ素含有化合物をセメント系材料に添加して、中性子遮蔽能を改良することが考えられる。しかしながら、ホウ素含有化合物をセメント系材料に添加すると、ホウ素含有化合物がセメントの水和反応を阻害し、セメントの硬化不良を生じるため、遮蔽体に十分な強度を与えられないなどの問題があった。このため、水硬性材料としてのセメント材料と、中性子遮蔽性のあるホウ素含有化合物とを含む中性子遮蔽体における硬化阻害の抑制が求められている。
2. Description of the Related Art Conventionally, structures such as nuclear power facilities and facilities housing radiation generating devices are covered with thick shields made of concrete or the like in order to prevent radiation generated inside from being released to the outside.
In particular, it is difficult to effectively shield neutron beams because their behavior changes depending on the amount of energy.For example, shielding bodies made of concrete must be considerably thick to ensure sufficient shielding performance. It was necessary.
Boron is known as an element that absorbs neutrons, and it may be possible to improve the neutron shielding ability by adding boron-containing compounds such as colemanite and hirgadite to cement materials. However, when boron-containing compounds are added to cement-based materials, the boron-containing compounds inhibit the hydration reaction of cement, resulting in poor hardening of the cement, resulting in problems such as not being able to provide sufficient strength to the shield. . Therefore, there is a need to suppress curing inhibition in a neutron shielding body containing a cement material as a hydraulic material and a boron-containing compound having neutron shielding properties.
セメント材料のホウ素含有化合物による硬化阻害の抑制を目的とした技術として、粗骨材にホウ素を含むコレマナイトを使用し、コレマナイト骨材の表面をアクリル系エマルジョンでコーティングして、セメント組成物に配合した中性子遮蔽体が提案されている（特許文献１参照）。
別の態様として、骨材にホウ素を含むコレマナイトを使用し、セメント組成物に、鉱油と水とを界面活性剤を用いて乳化させた特殊な混和剤及び玻璃質粉を含有させてなる中性子遮蔽コンクリート組成物が提案されている（特許文献２参照）。
As a technology aimed at suppressing curing inhibition caused by boron-containing compounds in cement materials, we used colemanite containing boron as coarse aggregate, coated the surface of the colemanite aggregate with an acrylic emulsion, and incorporated it into a cement composition. A neutron shield has been proposed (see Patent Document 1).
In another embodiment, a neutron shielding device uses colemanite containing boron as the aggregate, and contains a special admixture in which mineral oil and water are emulsified using a surfactant and glass powder in the cement composition. A concrete composition has been proposed (see Patent Document 2).
また、硬化阻害が懸念されるセメントを用いない中性子遮蔽体として、アルミナケイ酸塩酸化物を主成分とするジオポリマとボロン鉱とを含有するジオポリマ硬化体が提案され、ボロン鉱を含有しても強度が低下し難く、長期間使用しうる中性子遮蔽体が得られると記載されている（特許文献３参照）。 In addition, as a neutron shielding material that does not use cement, which is concerned about curing inhibition, a geopolymer hardened material containing a geopolymer whose main component is alumina silicate oxide and boronite has been proposed. It is stated that it is possible to obtain a neutron shielding body that does not easily deteriorate in neutron shielding properties and can be used for a long period of time (see Patent Document 3).
しかしながら、特許文献１に記載される技術では、コレマナイト表面が被覆されることでセメントの硬化阻害はある程度抑制されるが、粗骨材であるコレマナイトを均一に被覆することは困難であり、製造工程が煩雑であった。また、特許文献２に記載の方法では、鉱油と特殊な混和剤が必要となり、且つ、セメントにおいてもアルミナセメントが好ましいとされてはいるが、アルミナセメントでは必要な強度が得難いという問題がある。
一方、硬化性材料として、フライアッシュ、高炉スラグ等の粉体とアルカリ金属塩とを含むジオポリマを用いた特許文献３に記載の硬化体は、ホウ素含有化合物であるボロン鉱を骨材として用いても硬化阻害は生じない。しかし、得られたジオポリマ硬化体は、本発明者の検討によれば、実用上十分な強度が得難いという問題があった。
However, in the technology described in Patent Document 1, although inhibition of hardening of cement is suppressed to some extent by coating the colemanite surface, it is difficult to uniformly coat colemanite, which is a coarse aggregate, and the manufacturing process was complicated. Further, the method described in Patent Document 2 requires mineral oil and a special admixture, and although alumina cement is said to be preferable for cement, there is a problem that it is difficult to obtain the necessary strength with alumina cement.
On the other hand, the hardened material described in Patent Document 3 using a geopolymer containing powder such as fly ash or blast furnace slag and an alkali metal salt as a hardening material uses boronite, a boron-containing compound, as an aggregate. However, no curing inhibition occurs. However, the obtained cured geopolymer body had a problem in that it was difficult to obtain a strength sufficient for practical use, according to studies by the present inventors.
本発明の一実施形態の課題は、中性子を吸収するホウ素含有化合物を含有し、強度発現が良好な中性子遮蔽体を提供することである。 An object of an embodiment of the present invention is to provide a neutron shield that contains a boron-containing compound that absorbs neutrons and exhibits good strength.
課題を解決するための手段は、以下の実施形態を含む。 Means for solving the problem include the following embodiments.
＜１＞ フライアッシュ及び高炉スラグからなる群より選択される粉体の少なくとも１種と、ケイ酸のアルカリ金属塩と、コレマナイト及びヒルガダイトからなる群より選択されるホウ素含有化合物の少なくとも１種と、を含む中性子遮蔽体であり、前記中性子遮蔽体が含む前記粉体の総量に対する高炉スラグの含有量が３０質量％以上である中性子遮蔽体。 <1> At least one powder selected from the group consisting of fly ash and blast furnace slag, an alkali metal salt of silicic acid, and at least one boron-containing compound selected from the group consisting of colemanite and hirgadite; A neutron shielding body comprising: a neutron shielding body, wherein the content of blast furnace slag is 30% by mass or more based on the total amount of the powder contained in the neutron shielding body.
セメント系の硬化性組成物に、中性子遮蔽能を有するホウ素含有化合物を加えるとコンクリートの硬化阻害が生ずる。一方、フライアッシュ、高炉スラグ等を含む硬化性組成物では、アルミニウムシリケート粉末に含まれるアルミニウム（Ａｌ）、ケイ素（Ｓｉ）などがアルカリシリカ溶液中で溶解して金属イオンが生成され、その金属イオンが溶液成分とさらに反応することでポリマー化して硬化する。このため、ホウ素含有化合物を用いても硬化阻害が生じない。本実施形態では、フライアッシュ、高炉スラグ等を含む粉体の総量における高炉スラグの含有量を３０質量％以上とすることで、フライアッシュに対して、より反応性が高いという利点を有する高炉スラグの機能により、硬化体の良好な強度発現を実現していると推定される。 When a boron-containing compound with neutron shielding ability is added to a cement-based curable composition, hardening of concrete is inhibited. On the other hand, in a curable composition containing fly ash, blast furnace slag, etc., aluminum (Al), silicon (Si), etc. contained in aluminum silicate powder are dissolved in an alkali silica solution to generate metal ions. Further reacts with solution components to polymerize and harden. Therefore, even if a boron-containing compound is used, curing inhibition does not occur. In this embodiment, by setting the content of blast furnace slag to 30% by mass or more in the total amount of powder including fly ash, blast furnace slag, etc., blast furnace slag has the advantage of being more reactive to fly ash. It is presumed that this function realizes good strength development of the cured product.
＜２＞ 前記ホウ素含有化合物は累積５０％の粒径が３０μｍ以下であり、
前記中性子遮蔽体が含む前記粉体の総量の１０質量％～５０質量％を前記ホウ素含有化合物で置換してなる＜１＞に記載の中性子遮蔽体。
<2> The boron-containing compound has a cumulative 50% particle size of 30 μm or less,
The neutron shielding body according to <1>, wherein 10% by mass to 50% by mass of the total amount of the powder contained in the neutron shielding body is replaced with the boron-containing compound.
中性子遮蔽体において、ホウ素含有化合物を粒径が３０μｍ以下の粉体の状態で含有させることで、硬化体内により均一にホウ素含有化合物を分散して含有させることができ、中性子遮蔽性を安定なものとすることができる。さらに、粉体総量に対するホウ素含有化合物の置換量を１０質量％～５０質量％の範囲とすることで、硬化体としての中性子遮蔽体の形成に必要な成分量の確保が可能になり、ホウ素含有化合物が有する良好な中性子遮蔽能と、硬化体のより良好な強度発現とを両立することができる。 In the neutron shielding material, by containing the boron-containing compound in the form of powder with a particle size of 30 μm or less, the boron-containing compound can be more uniformly dispersed and contained in the cured body, resulting in stable neutron shielding properties. It can be done. Furthermore, by setting the substitution amount of the boron-containing compound to the total amount of powder in the range of 10% to 50% by mass, it is possible to secure the amount of components necessary for forming a neutron shield as a hardened product, and the boron-containing It is possible to achieve both good neutron shielding ability of the compound and better strength development of the cured product.
＜３＞ 前記中性子遮蔽体が含む粉体の総量に対する前記高炉スラグの含有量が５０質量％以上である＜１＞又は＜２＞に記載の中性子遮蔽体。
粉体総量に対し、高炉スラグの含有量をより高くすることで、強度発現と中性子遮蔽能とが高レベルで両立できる。
<3> The neutron shielding body according to <1> or <2>, wherein the content of the blast furnace slag is 50% by mass or more based on the total amount of powder contained in the neutron shielding body.
By increasing the content of blast furnace slag relative to the total amount of powder, both strength development and neutron shielding ability can be achieved at a high level.
本明細書において、「～」を用いて示された数値範囲は、「～」の前後に記載される数値をそれぞれ最小値及び最大値として含む範囲を示す。
本明細書において、組成物中の各成分の量は、組成物中に各成分に該当する物質が複数存在する場合、特に断らない限り、組成物中に存在する当該複数の物質の合計量を意味する。
In this specification, a numerical range indicated using "~" indicates a range that includes the numerical values written before and after "~" as the minimum and maximum values, respectively.
In the present specification, when there are multiple substances corresponding to each component in the composition, unless otherwise specified, the amount of each component in the composition refers to the total amount of the multiple substances present in the composition. means.
なお、本開示の中性子遮蔽体は、水硬性材料としてのセメントを含有せず、ケイ酸のアルカリ金属塩とフライアッシュ、高炉スラグなどを硬化性材料として用い、さらに水を含有する組成物の重合反応による硬化体である。 Note that the neutron shielding body of the present disclosure does not contain cement as a hydraulic material, uses an alkali metal salt of silicic acid, fly ash, blast furnace slag, etc. as a hardening material, and further comprises polymerization of a composition containing water. It is a hardened product caused by a reaction.
本発明の一実施形態によれば、中性子を吸収するホウ素含有化合物を含有し、強度発現が良好な中性子遮蔽体を提供することができる。 According to one embodiment of the present invention, it is possible to provide a neutron shield that contains a boron-containing compound that absorbs neutrons and has good strength development.
＜中性子遮蔽体＞
本開示の中性子遮蔽体は、フライアッシュ及び高炉スラグからなる群より選択される粉体の少なくとも１種と、ケイ酸のアルカリ金属塩と、コレマナイト及びヒルガダイトからなる群より選択されるホウ素含有化合物の少なくとも１種と、を含む中性子遮蔽体であり、中性子遮蔽体が含む粉体の総量に対する高炉スラグの含有量が３０質量％以上である中性子遮蔽体である。
<Neutron shield>
The neutron shielding body of the present disclosure includes at least one powder selected from the group consisting of fly ash and blast furnace slag, an alkali metal salt of silicic acid, and a boron-containing compound selected from the group consisting of colemanite and hirgadite. This is a neutron shielding body containing at least one kind, and the content of blast furnace slag is 30% by mass or more based on the total amount of powder contained in the neutron shielding body.
（フライアッシュ及び高炉スラグからなる群より選択される粉体）
本開示の中性子遮蔽体はフライアッシュ及び高炉スラグからなる群より選択される粉体の少なくとも１種を含む。
(Powder selected from the group consisting of fly ash and blast furnace slag)
The neutron shielding body of the present disclosure includes at least one kind of powder selected from the group consisting of fly ash and blast furnace slag.
（１）フライアッシュ
本開示の中性子遮蔽体に用い得るフライアッシュには、特に制限はなく、公知のフライアッシュを適宜使用することができる。例えば、ＪＩＳ Ａ ６２０１（２０１５年）に規定されるＩ種及びＩＩ種が挙げられる。
本明細書におけるフライアッシュは、石炭、石油、木材などを燃焼したときに出る廃ガスに含まれる細かい灰の粒子を指し、化学成分としてシリカ（酸化ケイ素）、アルミナ（酸化アルミニウム）、酸化カルシウム、炭素などを含む粉体である。
火力発電所などで、微粉炭を燃焼させた際に排出される廃ガスに含まれるフライアッシュは、一般に、コンクリートの混和材として、セメントに混ぜて使用される。フライアッシュは、粒子がなめらかな球状をしており、中性子遮蔽体の形成用組成物に添加した場合、組成物の流動性がより良好となる。
フライアッシュは、中性子遮蔽体の形成用組成物に含まれる後述のケイ酸のアルカリ金属塩等と反応して不溶解性の物質を形成することができ、得られた遮蔽体の密実性がより高まり、高強度の中性子遮蔽体の形成に有用である。
フライアッシュとしては、中性子遮蔽体の形成用組成物を用いて、中性子遮蔽体を成形する際の流動性、作業性等を考慮すれば、粉末度が２０００ｃｍ２／ｇ以上１００００ｃｍ２／ｇ以下のものが好ましく、２５００ｃｍ２／ｇ以上５０００ｃｍ２／ｇ以下のものがより好ましい。
フライアッシュの粉末度は、ＪＩＳ Ｒ ５２０１（２０１５年）記載のセメントの粉末度の測定方法に準じて測定することができる。粉末度は、フライアッシュを分級することにより制御することができる。
(1) Fly Ash There are no particular restrictions on the fly ash that can be used in the neutron shield of the present disclosure, and any known fly ash can be used as appropriate. Examples include Type I and Type II defined in JIS A 6201 (2015).
In this specification, fly ash refers to fine ash particles contained in waste gas emitted when coal, oil, wood, etc. are burned, and its chemical components include silica (silicon oxide), alumina (aluminum oxide), calcium oxide, It is a powder containing carbon, etc.
Fly ash, which is contained in the waste gas emitted when pulverized coal is burned at thermal power plants, is generally used as an admixture for concrete by mixing it with cement. Fly ash has smooth spherical particles, and when added to a composition for forming a neutron shield, the composition has better fluidity.
Fly ash can form an insoluble substance by reacting with the alkali metal salt of silicic acid (described below) included in the composition for forming a neutron shield, and the density of the resulting shield increases. It is useful for forming a high-strength neutron shield.
The fly ash should have a powder degree of 2000 cm 2 /g or more and 10000 cm 2 /g or less, considering fluidity, workability, etc. when forming a neutron shield using a composition for forming a neutron shield. It is preferably 2,500 cm 2 /g or more and 5,000 cm 2 /g or less.
The fineness of fly ash can be measured according to the method for measuring the fineness of cement described in JIS R 5201 (2015). Fineness can be controlled by classifying the fly ash.
（２）高炉スラグ
本開示の中性子遮蔽体の形成用組成物に用い得る高炉スラグには特に制限はなく、公知の高炉スラグを適宜使用することができる。高炉スラグとしては、例えば、ＪＩＳ Ａ６２０６（２０１３年）に規定されるものが挙げられる。
高炉スラグとしては、中性子遮蔽体の形成用組成物を用いて、中性子遮蔽体を成形する際の流動性、作業性等を考慮すれば、粉末度が２５００ｃｍ２／ｇ以上１３０００ｃｍ２／ｇ以下のものが好ましく、３０００ｃｍ２／ｇ以上７０００ｃｍ２／ｇ以下のものがより好ましい。
高炉スラグの粉末度は、フライアッシュの粉末度と同様、ＪＩＳ Ｒ ５２０１（２０１５年）記載のセメントの粉末度の測定方法に準じて測定することができる。粉末度は、高炉水砕スラグを粉砕する時の粉砕方法、粉砕条件や粉砕後の分級により制御することができる。
(2) Blast Furnace Slag There is no particular restriction on the blast furnace slag that can be used in the composition for forming a neutron shield of the present disclosure, and any known blast furnace slag can be used as appropriate. Examples of blast furnace slag include those specified in JIS A6206 (2013).
Blast furnace slag should have a fineness of 2,500 cm 2 /g or more and 13,000 cm 2 /g or less, considering fluidity, workability, etc. when forming a neutron shield using a composition for forming a neutron shield. It is preferably 3000 cm 2 /g or more and 7000 cm 2 /g or less.
The fineness of blast furnace slag, like the fineness of fly ash, can be measured according to the method for measuring the fineness of cement described in JIS R 5201 (2015). The degree of fineness can be controlled by the pulverization method used when pulverizing granulated blast furnace slag, the pulverization conditions, and the classification after pulverization.
また、フライアッシュ及び高炉スラグ以外の粉体を含有してもよい。フライアッシュ及び高炉スラグ以外の粉体（以下、その他の粉体と称することがある）としては、石灰石微粉末、ゴミ焼却灰、メタカオリン、シリカフューム、下水汚泥微粉末等が挙げられる。前記その他の粉体は、いずれもアルカリ金属塩と併用することで硬化性に寄与するため、併用によって中性子遮蔽体の強度発現を低下させる可能性は低いと考えられる。 Further, powders other than fly ash and blast furnace slag may be contained. Examples of powders other than fly ash and blast furnace slag (hereinafter sometimes referred to as other powders) include fine limestone powder, garbage incineration ash, metakaolin, silica fume, and fine sewage sludge powder. Since all of the other powders mentioned above contribute to curability when used in combination with an alkali metal salt, it is thought that there is a low possibility that their combined use will reduce the strength development of the neutron shield.
本開示の中性子遮蔽体は、フライアッシュ及び高炉スラグから選ばれる粉体の少なくとも１種を含有し、粉体を２種以上含有してもよい。
粉体を２種以上含有する場合、フライアッシュから選ばれる１種以上の粉体と、高炉スラグから選ばれる１種以上の粉体とを含有してもよく、高炉スラグから選ばれる互いに種類の異なる２種以上の粉体を含有してもよく、フライアッシュから選ばれる１種以上の粉体と、高炉スラグから選ばれる１種以上の粉体と、その他の粉体の少なくとも１種とを含有してもよい。
中性子遮蔽体が粉体を２種以上含有する場合、中性子遮蔽体が含む粉体の総量に対する高炉スラグの含有量が３０質量％以上であり、４０質量％以上が好ましく、５０質量％以上がより好ましい。
高炉スラグの含有量の上限には特に制限はなく、粉体がすべて高炉スラグであってもよい。
中性子遮蔽体が含む粉体の総量に対する高炉スラグの含有量が上記範囲にあることで、中性子遮蔽体は、実用上十分な強度発現を得ることができる。
The neutron shielding body of the present disclosure contains at least one kind of powder selected from fly ash and blast furnace slag, and may contain two or more kinds of powder.
When containing two or more types of powder, it may contain one or more types of powder selected from fly ash and one or more types of powder selected from blast furnace slag, or each type of powder selected from blast furnace slag. It may contain two or more different powders, including one or more powders selected from fly ash, one or more powders selected from blast furnace slag, and at least one other powder. May be contained.
When the neutron shield contains two or more types of powder, the content of blast furnace slag relative to the total amount of powder contained in the neutron shield is 30% by mass or more, preferably 40% by mass or more, and more preferably 50% by mass or more. preferable.
There is no particular restriction on the upper limit of the content of blast furnace slag, and all of the powder may be blast furnace slag.
When the content of blast furnace slag with respect to the total amount of powder contained in the neutron shielding body is within the above range, the neutron shielding body can obtain practically sufficient strength development.
中性子遮蔽体が含む粉体の総量に対する高炉スラグの含有量が上記範囲にあること以外に、粉体には特に制限はなく、粉体の種類と量とは、目的とする中性子遮蔽体の中性子遮蔽能、強度等の物性に応じて適宜選択することができる。 There are no particular restrictions on the powder other than that the content of blast furnace slag in the total amount of powder contained in the neutron shield is within the above range, and the type and amount of powder are It can be appropriately selected depending on physical properties such as shielding ability and strength.
（３）ケイ酸のアルカリ金属塩
本開示の中性子遮蔽体はケイ酸のアルカリ金属塩を含有する。
ケイ酸のアルカリ金属塩を含有することで、ケイ酸モノマー（Ｓｉ（ＯＨ）４）が硬化に寄与し、さらに、アルカリ金属塩を含有することで、水溶性が良好となり、硬化に寄与するアルカリ源ともなる。
ケイ酸のアルカリ金属塩としては、ケイ酸ナトリウム、ケイ酸カリウム、ケイ酸リチウム等が挙げられ、入手容易性の観点からケイ酸ナトリウムが好ましい。
なお、ケイ酸ナトリウムとしては、水ガラスと称されるケイ酸ナトリウム水溶液を用いてもよい。水ガラスは市販品を用いることができ、市販の水ガラスはＳｉＯ２とＮａ２Ｏとを含む。水ガラスとしては、硬化性の観点から、ＳｉＯ２を２０質量％～４０質量％含み、かつ、Ｎａ２Ｏを５質量％～２０質量％含むものが好ましい。
ケイ酸のアルカリ金属塩は、中性子遮蔽体の粉体の総量に対し、質量比で０．１～０．７であることが好ましく、０．２～０．５であることがより好ましい。
(3) Alkali metal salt of silicic acid The neutron shield of the present disclosure contains an alkali metal salt of silicic acid.
By containing an alkali metal salt of silicic acid, the silicic acid monomer (Si(OH) 4 ) contributes to curing, and furthermore, by containing an alkali metal salt, water solubility becomes good and the alkali that contributes to curing It also becomes the source.
Examples of the alkali metal salt of silicic acid include sodium silicate, potassium silicate, lithium silicate, etc., and sodium silicate is preferred from the viewpoint of easy availability.
Note that as the sodium silicate, an aqueous sodium silicate solution called water glass may be used. Commercially available water glass can be used, and commercially available water glass contains SiO 2 and Na 2 O. From the viewpoint of curability, the water glass preferably contains 20% by mass to 40% by mass of SiO 2 and 5% by mass to 20% by mass of Na 2 O.
The alkali metal salt of silicic acid preferably has a mass ratio of 0.1 to 0.7, more preferably 0.2 to 0.5, based on the total amount of powder of the neutron shielding body.
（４）コレマナイト及びヒルガダイトからなる群より選択されるホウ素含有化合物：特定ホウ素化合物
本開示の中性子遮蔽体は、コレマナイト及びヒルガダイトからなる群より選択されるホウ素含有化合物を含有する。コレマナイト（２ＣａＯ・３Ｂ２Ｏ３・５Ｈ２Ｏ）及びヒルガダイト（Ｃａ８（Ｂ２Ｏ１１）Ｃｌ４・４Ｈ２Ｏ）は、中性子遮蔽性が良好なホウ素含有化合物として知られている。
中性子遮蔽体は、特定ホウ素化合物を種々の形態で含むことができる。特定ホウ素化合物は、粉体として含まれてもよく、さらに、細骨材、粗骨材に相当するサイズの粒子として含まれてもよい。
(4) Boron-containing compound selected from the group consisting of colemanite and hirgadite: specific boron compound The neutron shield of the present disclosure contains a boron-containing compound selected from the group consisting of colemanite and hirugadite. Collemanite (2CaO.3B 2 O 3.5H 2 O) and hilgadite (Ca 8 (B 2 O 11 )Cl 4.4H 2 O ) are known as boron-containing compounds with good neutron shielding properties.
The neutron shield can contain the specific boron compound in various forms. The specific boron compound may be contained in the form of a powder, and further may be contained in the form of particles having a size corresponding to fine aggregate or coarse aggregate.
なかでも、特定ホウ素化合物は、累積５０％粒径が３０μｍ以下の粉体として含まれることが好ましい。
本開示の好ましい態様として、ホウ素含有化合物は累積５０％の粒径が３０μｍ以下であり、前記中性子遮蔽体が含む前記粉体の総量の１０質量％～５０質量％を前記ホウ素含有化合物で置換してなる中性子遮蔽体が挙げられる。
特定ホウ素化合物を累積５０％粒径が３０μｍ以下の粉体の状態で、中性子遮蔽体に含有させることで、中性子遮蔽体において、特定ホウ素化合物を、高炉スラグなどの粉体とともに微細な粉末として、より均一に分散して含有させることができる。このため、特定ホウ素化合物の含有量が少量でも、中性子遮蔽性を安定なものとすることができると考えられる。
特定ホウ素化合物を粉体として含有する場合、累積５０％粒径は１０μｍ～３０μｍの範囲であることがより好ましい。
なお、特定ホウ素化合物の累積５０％の粒径は、レーザー回折／散乱式粒子径分布測定装置を用いて測定することができる。本開示では、レーザー回折／散乱式粒子径分布測定装置（ＬＡ－９５０：（株）堀場製作所製）を用いて測定した値を記載している。
Among these, it is preferable that the specific boron compound is contained as a powder having a cumulative 50% particle size of 30 μm or less.
In a preferred embodiment of the present disclosure, the boron-containing compound has a cumulative particle size of 50% of 30 μm or less, and the boron-containing compound replaces 10% to 50% by mass of the total amount of the powder contained in the neutron shielding body. An example of this is a neutron shield made up of:
By containing the specific boron compound in the form of a powder with a cumulative 50% particle size of 30 μm or less in the neutron shield, the specific boron compound can be contained in the neutron shield as a fine powder together with powder such as blast furnace slag. It can be contained in a more uniformly dispersed manner. Therefore, it is considered that even if the content of the specific boron compound is small, the neutron shielding property can be stabilized.
When the specific boron compound is contained as a powder, the cumulative 50% particle size is more preferably in the range of 10 μm to 30 μm.
Note that the cumulative particle size of 50% of the specific boron compound can be measured using a laser diffraction/scattering particle size distribution measuring device. In the present disclosure, values measured using a laser diffraction/scattering particle size distribution measuring device (LA-950: manufactured by Horiba, Ltd.) are described.
特定ホウ素化合物を粉体として含有する場合には、既述のように、中性子遮蔽体が含む粉体の総量の１０質量％～５０質量％を粉体状態のホウ素含有化合物で置換することが好ましく、粉体の総量の２０質量％～３０質量％をホウ素含有化合物粉体で置換することがより好ましい。 When the specific boron compound is contained as a powder, as described above, it is preferable to replace 10% by mass to 50% by mass of the total amount of powder contained in the neutron shielding body with the boron-containing compound in powder form. More preferably, 20% to 30% by mass of the total amount of powder is replaced with boron-containing compound powder.
特定ホウ素化合物は、細骨材のサイズで含有されてもよい。細骨材のサイズの特定ホウ素化合物を含有する場合、細骨材の一部を特定ホウ素化合物に置換して含有してもよい。
細骨材のサイズは、通常、７５μｍ以上５ｍｍ（５０００μｍ）以下であり、細骨材サイズの特定ホウ素化合物を含有する場合、特定ホウ素化合物のサイズは、累積５０％粒径が０．６ｍｍ～２．５ｍｍの範囲であることが好ましく、０．６ｍｍ～１．２ｍｍの範囲であることがより好ましい。
細骨材のサイズの特定ホウ素化合物を含有する場合、細骨材のサイズの特定ホウ素化合物は、通常骨材よりも強度がより低いため、中性子遮蔽体が含む細骨材の総量の１０質量％～５０質量％を置換することが好ましい。
細骨材サイズの特定ホウ素化合物の置換量が上記範囲であることで、良好な中性子遮蔽性と、強度との両立ができるため、好ましい。
The specific boron compound may be contained in the size of fine aggregate. When containing a specific boron compound of the size of fine aggregate, a part of the fine aggregate may be replaced with the specific boron compound.
The size of fine aggregate is usually 75 μm or more and 5 mm (5000 μm) or less, and when it contains a specific boron compound of fine aggregate size, the size of the specific boron compound is such that the cumulative 50% particle size is 0.6 mm to 2. It is preferably in the range of .5 mm, and more preferably in the range of 0.6 mm to 1.2 mm.
When containing a specific boron compound of the size of fine aggregate, the specific boron compound of the size of fine aggregate has lower strength than normal aggregate, so 10% by mass of the total amount of fine aggregate contained in the neutron shield. It is preferable to substitute up to 50% by mass.
It is preferable that the amount of substitution of the specific boron compound in the fine aggregate size is within the above range, since both good neutron shielding properties and strength can be achieved.
特定ホウ素化合物は、粗骨材のサイズで含有されてもよい。
粗骨材のサイズは、通常、５ｍｍ以上２０ｍｍ以下であり、粗骨材のサイズの特定ホウ素化合物を含有する場合、粗骨材のサイズの特定ホウ素化合物は、通常骨材よりも強度がより低い。このため、粗骨材のサイズの特定ホウ素化合物は、中性子遮蔽体が含む粗骨材の総量に対し１０質量％～３０質量％の範囲で置換することが好ましい。
The specific boron compound may be contained in the size of coarse aggregate.
The size of the coarse aggregate is usually 5 mm or more and 20 mm or less, and when it contains a specific boron compound of the size of the coarse aggregate, the specific boron compound of the size of the coarse aggregate has lower strength than the normal aggregate. . Therefore, it is preferable that the specific boron compound of the size of the coarse aggregate is substituted in a range of 10% by mass to 30% by mass based on the total amount of coarse aggregate contained in the neutron shield.
本開示の中性子遮蔽体は、効果を損なわない範囲において、上記特定ホウ素化合物以外のホウ素含有化合物をさらに含んでもよい。その他のホウ素含有化合物としては、ボロン鉱の１種であるウレキナイト（ＮａＣａＢ５Ｏ６（ＯＨ）６・Ｈ２Ｏ）、ホウ砂、Ｂ４Ｃ、ＢＮ等が挙げられる。 The neutron shielding body of the present disclosure may further contain a boron-containing compound other than the specific boron compound described above, within a range that does not impair the effect. Other boron-containing compounds include urekinite (NaCaB 5 O 6 (OH) 6.H 2 O), which is a type of boronite, borax, B 4 C, BN, and the like.
（水）
本開示の中性子遮蔽体を形成する際に用いる中性子遮蔽体の形成用組成物は、前記した各成分に加え、分散媒としての水を含有することができる。
水には、特に制限はなく、水道水、精製水、イオン交換水、純水などのいずれも使用することができる。
なかでも、経済性の観点から、水道水を用いることが好ましい。
(water)
The composition for forming a neutron shield used in forming the neutron shield of the present disclosure can contain water as a dispersion medium in addition to the above-mentioned components.
Water is not particularly limited, and any of tap water, purified water, ion exchange water, pure water, etc. can be used.
Among these, from the viewpoint of economy, it is preferable to use tap water.
中性子遮蔽体の製造方法としては、上記各成分に加え、水、骨材、その他、一般に水硬性材料に用い得る公知の添加剤を、効果を損なわない限りにおいて用いて、中性子遮蔽体の形成用組成物を調製し、得られた組成物を成形する方法が挙げられる。 In addition to the above-mentioned components, water, aggregate, and other known additives that can generally be used in hydraulic materials are used to produce the neutron shield, as long as the effectiveness is not impaired. Examples include a method of preparing a composition and molding the obtained composition.
本開示の中性子遮蔽体は、中性子を吸収する特定ホウ素化合物を含有し、強度発現が良好である。このため、本開示の中性子遮蔽体は、特定ホウ素化合物を用いたセメント製の遮蔽体に比較して、中性子遮蔽性と強度がより良好であり、種々の用途に使用することができる。
また、本開示の中性子遮蔽体を構成する硬化性の成分であるフライアッシュ、高炉スラグ、ケイ酸のアルカリ金属塩は、セメントと比べ二酸化炭素排出量の少ないこと、フライアッシュや高炉スラグの副産物を利用することから環境負荷低減に貢献できる材料である。
The neutron shielding body of the present disclosure contains a specific boron compound that absorbs neutrons, and exhibits good strength. Therefore, the neutron shielding body of the present disclosure has better neutron shielding properties and strength than a cement shielding body using a specific boron compound, and can be used for various purposes.
In addition, fly ash, blast furnace slag, and alkali metal salts of silicic acid, which are the hardening components that make up the neutron shield of the present disclosure, have lower carbon dioxide emissions than cement, and are free from byproducts of fly ash and blast furnace slag. It is a material that can contribute to reducing environmental impact when used.
以下、具体例を挙げて本開示の中性子遮蔽体について詳細に説明するが、以下の実施例は、本開示における一態様を示すものである。本開示は、その主旨を逸脱しない限り種々の変型例が可能であり、以下の記載に限定されない。
なお、特に断らない限りにおいて、以下の「％」及び「部」は質量基準である。
Hereinafter, the neutron shielding body of the present disclosure will be described in detail by giving specific examples, and the following examples illustrate one aspect of the present disclosure. The present disclosure can be modified in various ways without departing from the spirit thereof, and is not limited to the following description.
Note that unless otherwise specified, "%" and "parts" below are based on mass.
以下に示す処方に従い、硬化性材料により硬化体を調製し、得られた硬化体を用いて評価を行った。 A cured product was prepared from a curable material according to the recipe shown below, and the obtained cured product was evaluated.
〔実施例１～実施例４、比較例１～比較例３〕
＜中性子遮蔽体の製造＞
下記材料を用いて、中性子遮蔽体の形成用組成物を調製し、モルタルフロー測定、圧縮強度試験を行った。
比較例２及び比較例３では、セメントモルタルを用いた中性子遮蔽体の形成用組成物を調製した。
[Example 1 to Example 4, Comparative Example 1 to Comparative Example 3]
<Manufacture of neutron shield>
A composition for forming a neutron shield was prepared using the following materials, and mortar flow measurements and compressive strength tests were conducted.
In Comparative Examples 2 and 3, compositions for forming neutron shields using cement mortar were prepared.
１．中性子遮蔽体の形成用組成物の材料
材料の名称に併記したかっこ内の名称は、各材料の略称であり、表中ではこの略称を用いて記載している。また、表中の「Ｗ」は水を表す。
1. Materials of composition for forming neutron shielding material The name in parentheses that is written together with the name of the material is the abbreviation of each material, and this abbreviation is used in the table. Moreover, "W" in the table represents water.
（１）粉体
・高炉スラグ微粉末（ＢＦＳ）
密度２．９１ｇ／ｃｍ３、粉末度４２２０ｃｍ２／ｇ
・フライアッシュ（ＦＡ）
密度２．２８ｇ／ｃｍ３、粉末度３６７０ｃｍ２／ｇ
（２）セメント（比較例用）
・ポルトランドセメント（Ｃ）
密度３．１６ｇ／ｃｍ３、粉末度３２８０ｃｍ２／ｇ
・高炉セメントＣ種（ＢＣ）
密度２．９８ｇ／ｃｍ３、高炉スラグ微粉末６２％含有
（３）アルカリ金属塩（水溶液）
・珪酸ナトリウム溶液（ＷＧ）：珪酸ソーダ２号、密度１．５０ｇ／ｃｍ３
・水酸化ナトリウム水溶液（ＮＨ）：１０ｍｏｌ／ｌ、密度１．３３ｇ／ｃｍ３
（４）特定ホウ素化合物
・コレマナイト（Ｃｌｔｅ）
密度２．５０ｇ／ｃｍ３、累積５０％粒径２０．７μｍ、Ｂ２Ｏ３：４０．１％
（Ｃｉｔｅの累積５０％粒径は、レーザー回折／散乱式粒子径分布測定装置
ＬＡ－９５０：（株）堀場製作所で測定した値である。）
（５）細骨材
・標準砂：絶乾密度２．６４ｇ／ｃｍ３
・再生細骨材：絶乾密度２．０６ｇ／ｃｍ３、表乾密度２．２９ｇ／ｃｍ３、吸水率１１．０８％
・コレマナイト細骨材：絶乾密度２．３８ｇ／ｃｍ３、表乾密度２．４４ｇ／ｃｍ３、吸水率２．４７％、粗粒率２．７１
(1) Powder/ground blast furnace slag powder (BFS)
Density 2.91g/cm 3 , fineness 4220cm 2 /g
・Fly ash (FA)
Density 2.28g/cm 3 , fineness 3670cm 2 /g
(2) Cement (for comparative example)
・Portland cement (C)
Density 3.16g/cm 3 , fineness 3280cm 2 /g
・Blast furnace cement type C (BC)
Density 2.98g/cm 3 , Contains 62% blast furnace slag powder (3) Alkali metal salt (aqueous solution)
・Sodium silicate solution (WG): Sodium silicate No. 2, density 1.50 g/cm 3
・Sodium hydroxide aqueous solution (NH): 10 mol/l, density 1.33 g/cm 3
(4) Specific boron compound/colemanite (Clte)
Density 2.50g/cm 3 , Cumulative 50% particle size 20.7 μm, B 2 O 3 : 40.1%
(The cumulative 50% particle size of Cite is a value measured by a laser diffraction/scattering particle size distribution analyzer LA-950: Horiba, Ltd.)
(5) Fine aggregate/standard sand: absolute dry density 2.64 g/cm 3
・Recycled fine aggregate: bone dry density 2.06 g/cm 3 , surface dry density 2.29 g/cm 3 , water absorption rate 11.08%
・Colemanite fine aggregate: bone dry density 2.38 g/cm 3 , surface dry density 2.44 g/cm 3 , water absorption 2.47%, coarse particle ratio 2.71
２．中性子遮蔽体の形成用組成物の調製
表１に記載の含有量で、各成分を混合し、モルタルミキサーで３分間練混ぜて、組成物を調製した。
2. Preparation of a composition for forming a neutron shield Each component was mixed at the content shown in Table 1 and kneaded for 3 minutes with a mortar mixer to prepare a composition.
３．中性子遮蔽体の形成用組成物の評価
・モルタルフロー
ＪＩＳ Ｒ ５２０１（２０１５年）に準じてモルタルのフローを測定した。
・圧縮強度
圧縮試験体は、型枠（φ５０×１００ｍｍ）を用いて、中性子遮蔽体の形成用組成物を投入し、２０℃で所定の材齢まで封緘養生して、硬化体（試験用中性子遮蔽体）を得た。
圧縮強度試験は、ＪＩＳ Ａ １１０８（２０１８年）に準拠し、材齢１週、４週に実施した。
3. Evaluation of Composition for Forming Neutron Shielder Mortar Flow Mortar flow was measured according to JIS R 5201 (2015).
・Compressive strength For the compression test specimen, a composition for forming a neutron shield was poured into a mold (φ50 x 100 mm), sealed and cured at 20°C until a specified material age, and the cured product (test neutron A shield) was obtained.
The compressive strength test was conducted at 1 week and 4 weeks of material age in accordance with JIS A 1108 (2018).
中性子遮蔽体の形成用組成物の配合、モルタルフロー、及び圧縮強度の結果を表１に示す。
実施例１～実施例４、及び比較例１では、高炉スラグ微粉末（ＢＦＳ）とフライアッシュ（ＦＡ）の粉体全量の３０質量％をコレマナイト（Ｃｌｔｅ）に置換し、比較例２及び比較例３では、セメント（Ｃ）の３０質量％をコレマナイト（Ｃｌｔｅ）に置換した。
なお、下記表において「－」は、当該成分を含まないことを示す。
The results of the formulation, mortar flow, and compressive strength of the composition for forming the neutron shield are shown in Table 1.
In Examples 1 to 4 and Comparative Example 1, 30% by mass of the total powder of blast furnace slag powder (BFS) and fly ash (FA) was replaced with colemanite (Clte), and Comparative Example 2 and Comparative Example In No. 3, 30% by mass of cement (C) was replaced with colemanite (Clte).
In the table below, "-" indicates that the component is not included.
実施例１～実施例４の中性子遮蔽体は、コレマナイトを使用しているにもかかわらず材齢１週において高い圧縮強度を示しており、材齢４週ではさらに圧縮強度が高くなった。
他方、粉体における高炉スラグの含有量が３０質量％未満である比較例１は、材齢４週でも、圧縮強度が３０Ｎ／ｍｍ２以下であり、実用上十分な強度発現が得られなかった。
耐久性や安全性の観点から、近年、構造物のコンクリート強度は高くなる傾向があり、さらに強度を確実に確保する上で圧縮強度試験に用いる強度試験体の強度は３０Ｎ／ｍｍ２以上が求められることが多くなっている。そのため、中性子遮蔽体においても試験では３０Ｎ／ｍｍ２以上の強度を有することが実用上必要となると考えられ、実施例１～実施例４は材齢１週または材齢４週でその強度を満足した。
The neutron shielding bodies of Examples 1 to 4 showed high compressive strength at one week of age despite using colemanite, and the compressive strength became even higher at four weeks of age.
On the other hand, in Comparative Example 1, in which the content of blast furnace slag in the powder was less than 30% by mass, the compressive strength was 30 N/mm 2 or less even at a material age of 4 weeks, and a practically sufficient strength was not obtained. .
From the viewpoint of durability and safety, the strength of concrete in structures has tended to increase in recent years, and in order to ensure strength, the strength of the strength test specimen used for compressive strength tests must be 30N/mm2 or higher. This is happening more and more often. Therefore, it is thought that it is practically necessary for neutron shields to have a strength of 30 N/mm 2 or more in tests, and Examples 1 to 4 satisfy this strength at a material age of 1 week or 4 weeks. did.
硬化性材料としてセメントを用いた比較例２及び比較例３の中性子遮蔽体では、材齢１週で硬化せず、材齢４週でも１５Ｎ／ｍｍ２以下と低い強度であった。
比較例３の高炉セメントＣ種を用いた組成物により得られた中性子遮蔽体は、材料として、セメント中に高炉スラグ微粉末（ＢＦＳ）を約３５０ｋｇ／ｍ３含んでいるにもかかわらず、圧縮強度が非常に低かった。これは、セメントの硬化反応をコレマナイト（Ｃｌｔｅ）が阻害したためと考えられる。
The neutron shielding bodies of Comparative Examples 2 and 3 using cement as the curable material did not harden after one week of age, and had a low strength of 15 N/mm 2 or less even after four weeks of age.
The neutron shield obtained from the composition using blast furnace cement type C of Comparative Example 3 was compressed even though the cement contained about 350 kg/ m3 of ground blast furnace slag (BFS) as a material. The intensity was very low. This is considered to be because colemanite (Clte) inhibited the hardening reaction of cement.
実施例１～実施例３の中性子遮蔽体の評価結果より、粉末の総量に対する高炉スラグ微粉末の含有比率を高くすることで、より高い圧縮強度の中性子遮蔽体を得ることができることがわかる。また、実施例４の中性子遮蔽体の評価結果より、骨材として再生骨材を用いた場合も、中性子遮蔽体は十分な強度を発現することがわかる。 From the evaluation results of the neutron shielding bodies of Examples 1 to 3, it can be seen that a neutron shielding body with higher compressive strength can be obtained by increasing the content ratio of pulverized blast furnace slag powder to the total amount of powder. Further, the evaluation results of the neutron shielding body of Example 4 show that the neutron shielding body exhibits sufficient strength even when recycled aggregate is used as the aggregate.
４．中性子遮蔽体の中性子遮蔽性能の検証
上記実施例１～実施例４の中性子遮蔽体のうち、実施例１～実施例３の中性子遮蔽体について、中性子線に対する遮蔽性能をモンテカルロ計算コードＰＨＩＴＳ（ＰＨＩＴＳ－２．８８， Ｐａｒｔｉｃｌｅ ａｎｄ Ｈｅａｖｙ Ｉｏｎ Ｔｒａｎｓｐｏｒｔ ｃｏｄｅ Ｓｙｓｔｅｍ， Ｔｈｅ Ｎｕｃｌｅａｒ Ｅｎｅｒｇｙ Ａｇｅｎｃｙ）により解析した。中性子遮蔽体の形成用組成物は原材料の配合から推定したものを用い、密度は硬化後に測定した嵩密度を用いた。
4. Verification of neutron shielding performance of neutron shields Among the neutron shields of Examples 1 to 4 above, the shielding performance against neutron beams of the neutron shields of Examples 1 to 3 was evaluated using the Monte Carlo calculation code PHITS (PHITS- 2.88, Particle and Heavy Ion Transport code System, The Nuclear Energy Agency). The composition for forming the neutron shield was estimated from the composition of the raw materials, and the density was the bulk density measured after curing.
Ｃｆ－２５２中性子線源に対する透過特性を図１に示す。対照例として普通コンクリートの中性子線の透過特性を併記した。図１は、実施例１～実施例３及び対照例の中性子遮蔽体の、中性子線源（Ｃｆ－２５２）に対する遮蔽性能を解析した、Ｃｆ－２５２中性子線の透過率と中性子遮蔽体の遮蔽厚との関係を示すグラフである。また、図２は、実施例１～実施例３間の特性をより明確にするために作成した、図１に示す実施例１～実施例３及び対照例のＣｆ－２５２中性子線の透過率と中性子遮蔽体の遮蔽厚との関係を示すグラフの遮蔽厚５０ｃｍまでの部分拡大図である。
図１及び図２に明らかな如く、実施例１～実施例３の中性子遮蔽体では透過特性には互いに大きな差はないが、普通コンクリート製の中性子遮蔽体に比べて優れた中性子線遮蔽効果を示し、中性子線源（Ｃｆ－２５２）に対して厚さ３５ｃｍで中性子線を１／１０以下に、厚さ６０ｃｍで中性子線を１／１００以下に、厚さ８５ｃｍで中性子線を１／１０００以下に減衰させる性能を有することが確認できた。
Figure 1 shows the transmission characteristics for a Cf-252 neutron source. As a control example, the neutron beam transmission characteristics of ordinary concrete are also shown. Figure 1 shows the transmittance of Cf-252 neutron beam and the shielding thickness of the neutron shield, which is an analysis of the shielding performance of the neutron shields of Examples 1 to 3 and the control example against a neutron beam source (Cf-252). It is a graph showing the relationship between In addition, FIG. 2 shows the transmittance of Cf-252 neutron beam of Examples 1 to 3 and the control example shown in FIG. 1, which were created to clarify the characteristics between Examples 1 to 3. It is a partially enlarged view of a graph showing the relationship with the shielding thickness of a neutron shield up to a shielding thickness of 50 cm.
As is clear from Figures 1 and 2, the neutron shields of Examples 1 to 3 do not have much difference in transmission characteristics, but they have superior neutron beam shielding effects compared to neutron shields made of ordinary concrete. neutron beam is reduced to 1/10 or less at a thickness of 35 cm, 1/100 or less at a thickness of 60 cm, and 1/1000 or less at a thickness of 85 cm for a neutron source (Cf-252). It was confirmed that it has the ability to attenuate
中性子線源（１００ｋｅＶ）に対する透過特性を図３に示す。実施例１～実施例３及び対照例の中性子遮蔽体の、中性子線源（１００ｋｅＶ）に対する遮蔽性能を解析した、１００ｋｅＶ中性子線の透過率と中性子遮蔽体の遮蔽厚との関係を示すグラフである。対照例として普通コンクリートの中性子線の透過特性を併記した。また、図４は、実施例１～実施例３の中性子遮蔽体の特性をより明確にするために作成した、図３に示す実施例１～実施例３及び対照例の１００ｋｅＶ中性子線の透過率と中性子遮蔽体の遮蔽厚との関係を示すグラフの遮蔽厚２０ｃｍまでの部分拡大図である。
中性子線源（１００ｋｅＶ）に対しては、より薄い厚みである厚さ１０ｃｍで中性子線を１／１０以下に、厚さ２０ｃｍ以下で中性子線を１／１００以下に、厚さ２５ｃｍ以下で中性子線を１／１０００以下に減衰させることができる性能を有していた。
The transmission characteristics for a neutron beam source (100 keV) are shown in FIG. It is a graph showing the relationship between the transmittance of a 100 keV neutron beam and the shielding thickness of the neutron shield, which is an analysis of the shielding performance of the neutron shields of Examples 1 to 3 and a control example against a neutron beam source (100 keV). . As a control example, the neutron beam transmission characteristics of ordinary concrete are also shown. In addition, FIG. 4 shows the transmittance of 100 keV neutron beams of Examples 1 to 3 and the control example shown in FIG. 3, which were created to clarify the characteristics of the neutron shields of Examples 1 to 3. It is a partially enlarged view of the graph showing the relationship between the shielding thickness of the neutron shield and the shielding thickness up to 20 cm.
For a neutron beam source (100 keV), a thinner thickness of 10 cm reduces the neutron beam to 1/10 or less, a thickness of 20 cm or less reduces the neutron beam to 1/100 or less, and a thickness of 25 cm or less reduces the neutron beam. It had the ability to attenuate to 1/1000 or less.
〔実施例５～実施例６〕
実施例５及び実施例６では、粉体をコレマナイトに置換せず、細骨材の３０質量％をコレマナイト細骨材に置換し、その他は、実施例１と同様にして中性子遮蔽体の形成用組成物を調製し、中性子遮蔽体を得て、実施例１と同様にして評価した。結果を表２に示す。
[Example 5 to Example 6]
In Examples 5 and 6, the powder was not replaced with colemanite, but 30% by mass of the fine aggregate was replaced with colemanite fine aggregate, and the other conditions were the same as in Example 1. A composition was prepared, a neutron shield was obtained, and evaluated in the same manner as in Example 1. The results are shown in Table 2.
表２の結果より、コレマナイト粉体ではなく、細骨材としてコレマナイトを使用した場合も、得られた中性子遮蔽体の形成用組成物は良好なフロー値を示し、且つ、中性子遮蔽体は、圧縮強度が良好であることが分かる。 From the results in Table 2, even when colemanite was used as a fine aggregate instead of colemanite powder, the resulting composition for forming a neutron shield showed a good flow value, and the neutron shield was compacted. It can be seen that the strength is good.
Claims (2)
前記中性子遮蔽体が含む前記粉体の総量に対する前記高炉スラグの含有量が３０質量％以上であり、
前記ホウ素含有化合物は累積５０％の粒径が３０μｍ以下であり、
前記中性子遮蔽体が含む前記粉体の総量の１０質量％～５０質量％を前記ホウ素含有化合物で置換してなる中性子遮蔽体。 A neutron containing at least one powder selected from the group consisting of fly ash and blast furnace slag, an alkali metal salt of silicic acid, and at least one boron-containing compound selected from the group consisting of colemanite and hirgadite. is a shield,
The content of the blast furnace slag with respect to the total amount of the powder contained in the neutron shield is 30% by mass or more,
The boron-containing compound has a cumulative 50% particle size of 30 μm or less,
A neutron shielding body obtained by replacing 10% by mass to 50% by mass of the total amount of the powder contained in the neutron shielding body with the boron-containing compound.
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| JP2006145421A (en) | 2004-11-22 | 2006-06-08 | Hazama Corp | Heat-resistant neutron shielding and the neutron shield method |
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| JP2014125375A (en) | 2012-12-26 | 2014-07-07 | Nippon Concrete Ind Co Ltd | Geopolymer cured product and method for manufacturing the same |
| JP2019014617A (en) | 2017-07-05 | 2019-01-31 | 株式会社竹中工務店 | Geopolymer composition and geopolymer-cured body |
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| JP2006145421A (en) | 2004-11-22 | 2006-06-08 | Hazama Corp | Heat-resistant neutron shielding and the neutron shield method |
| US20100229762A1 (en) | 2009-02-20 | 2010-09-16 | Construcciones Tecnicas De Radioterapia, S.L. | Mass for manufacturing products with a high neutron radioprotection capacity |
| JP2012127725A (en) | 2010-12-14 | 2012-07-05 | Taiheiyo Consultant:Kk | Neutron absorber |
| JP2014125375A (en) | 2012-12-26 | 2014-07-07 | Nippon Concrete Ind Co Ltd | Geopolymer cured product and method for manufacturing the same |
| JP2019014617A (en) | 2017-07-05 | 2019-01-31 | 株式会社竹中工務店 | Geopolymer composition and geopolymer-cured body |
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