JPH0827387B2 - Heat-resistant fast neutron shielding material - Google Patents
Heat-resistant fast neutron shielding materialInfo
- Publication number
- JPH0827387B2 JPH0827387B2 JP2267756A JP26775690A JPH0827387B2 JP H0827387 B2 JPH0827387 B2 JP H0827387B2 JP 2267756 A JP2267756 A JP 2267756A JP 26775690 A JP26775690 A JP 26775690A JP H0827387 B2 JPH0827387 B2 JP H0827387B2
- Authority
- JP
- Japan
- Prior art keywords
- metal hydride
- heat
- shielding material
- powder
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Description
【発明の詳細な説明】 〈産業上の利用分野〉 本発明は、中性子遮蔽（減速）能力に優れる金属水素
化物を高体積率に含有し、かつ、成形体として700℃を
超える高温まで安定な中性子遮蔽材に関するものであ
り、中性子遮蔽が必要となる広範な分野にその適用が可
能である。特に、原子炉については、炉容器内炉心周り
中性子遮蔽体、炉心内制御棒周り減速材等として適して
いる。また、核燃料および核原料物質使用施設の中性子
遮蔽材、使用済核燃料輸送容器用遮蔽材、ホットラボ内
遮蔽材、放射線発生装置（加速器等）の遮蔽材等に好ま
しく利用できる。DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention contains a metal hydride having a high neutron shielding (deceleration) ability in a high volume ratio, and is stable as a molded body at a high temperature exceeding 700 ° C. The present invention relates to a neutron shielding material, and can be applied to a wide range of fields requiring neutron shielding. In particular, for a nuclear reactor, it is suitable as a neutron shield around the core in the reactor vessel, a moderator around the control rod in the core, and the like. Further, it can be preferably used as a neutron shielding material for facilities using nuclear fuel and nuclear raw materials, a shielding material for a spent nuclear fuel transportation container, a shielding material in a hot laboratory, a shielding material for a radiation generator (accelerator, etc.), and the like.
〈従来の技術とその課題〉 中性子の減速材としては、Ｈ、Ｂ、Ｃ等の低原子番号
の元素を含有する物質が優れており、広く採用されてい
る。<Prior Art and Its Problems> As a neutron moderator, a substance containing an element having a low atomic number such as H, B, and C is excellent and is widely adopted.
金属水素化物は、有機材料や水と同程度の水素密度を
有し、高温で比較的水素解離圧の低い系を選択すること
により、700℃を超える高温下でも使用できる中性子遮
蔽材あるいは減速材としての可能性を有している。しか
し、金属水素化物それ自体は一般に脆く、特に300℃を
超える温度の上昇・下降を繰り返すことにより歪が解放
され、微粉化する。また、金属水素化物は温度の上昇に
伴い水素の解離が生じやすくなる。例えば、水素化ジル
コニウムの760℃での平衡解離圧は1atmであり、解離水
素を閉じ込める構造上の工夫と解離水素の圧力に耐えら
れる十分な強度を有する金属水素化物含有構造体をつく
る必要があった。Metal hydrides have a hydrogen density similar to that of organic materials and water, and by selecting a system with a relatively low hydrogen dissociation pressure at high temperatures, a neutron shielding material or moderator that can be used even at high temperatures exceeding 700 ° C. Has the potential as However, the metal hydride itself is generally brittle, and the strain is released and pulverized by repeating temperature rise and fall particularly above 300 ° C. Further, in the metal hydride, hydrogen is likely to dissociate as the temperature rises. For example, the equilibrium dissociation pressure of zirconium hydride at 760 ° C is 1 atm, and it is necessary to devise a structure for confining the dissociated hydrogen and to make a metal hydride-containing structure having sufficient strength to withstand the pressure of the dissociated hydrogen. It was
〈発明が解決しようとする問題点〉 従来は、高体積率の金属水素化物を含有しながら、70
0℃を超える高温と中性子照射環境下においても寸法安
定性に優れ、十分な機械的強度を持つ構造体を製造する
ことはもちろん、任意の形状の構造体に成形・加工する
ことは困難であった。<Problems to be Solved by the Invention> Conventionally, while containing a high volume fraction of metal hydride,
It is difficult not only to manufacture a structure with excellent dimensional stability and sufficient mechanical strength even at high temperatures exceeding 0 ° C and in a neutron irradiation environment, but also to mold and process it into a structure of any shape. It was
本発明は、高温まで安定な耐熱性物質を金属水素化物
粉末の結合剤すなわちバインダーとして導入し、この結
合剤によって金属水素化物含有成形体とすることによっ
て上記問題点を解決するものであり、以下のような特長
を有する耐熱高速中性子遮蔽材を提供するものである。The present invention is to solve the above problems by introducing a heat-resistant substance that is stable up to high temperatures as a binder of a metal hydride powder, that is, a binder, and forming a metal hydride-containing compact by this binder. The present invention provides a heat-resistant fast neutron shielding material having the following features.
高体積率の金属水素化物を安定に保持できる。A metal hydride having a high volume ratio can be stably held.
解離による金属水素化物からの水素ガスの放出を抑制
できる。Release of hydrogen gas from the metal hydride due to dissociation can be suppressed.
成形体として必要な寸法安定性、機械的強度を有す
る。It has the dimensional stability and mechanical strength required for a molded product.
700℃を超える高温下でも上記〜の特長を失わな
い。The above-mentioned features are not lost even at high temperatures above 700 ° C.
任意の形状に容易に成形・加工できる。Can be easily molded and processed into any shape.
〈問題点を解決するための手段〉 すなわち本発明による耐熱高速中性子遮蔽材は、珪酸
カルシウムと金属水素化物の粉末からなる混合成形体で
あって、珪酸カルシウム100重量部に対し、金属水素化
物を50〜800重量部含有し、珪酸カルシウムは珪酸質お
よび石灰質のCaO/SiO2モル比が0.5〜2.0の範囲であり、
金属水素化物はTi、Zr、Ｙ、Gd、Eu、Hf、Th、Ｕのいず
れかの金属で水素／金属原子比が0.7以上の範囲であ
り、上記金属水素化物の微粉末表面には酸化物被膜が生
成されていて複合粉末となっていることを特徴とするも
のである。<Means for Solving the Problems> That is, the heat-resistant fast neutron shielding material according to the present invention is a mixed compact made of powder of calcium silicate and metal hydride, and metal hydride is added to 100 parts by weight of calcium silicate. Containing 50 to 800 parts by weight, calcium silicate has a CaO / SiO 2 molar ratio of siliceous and calcareous in the range of 0.5 to 2.0,
The metal hydride is any metal of Ti, Zr, Y, Gd, Eu, Hf, Th, and U and has a hydrogen / metal atomic ratio of 0.7 or more, and an oxide is present on the surface of the fine powder of the metal hydride. It is characterized in that a coating film is formed and becomes a composite powder.
以下に本発明の遮蔽材の成形体構造、化学組成および
成形プロミスについて詳述する。The structure, chemical composition and molding promise of the shielding material of the present invention will be described in detail below.
１）．成形体構造 成形体は、添付図面に模式的に示すような構造を有す
る。すなわち、寸法５〜100μｍの金属水素化物粉末１
と寸法１〜10μｍの珪酸カルシウムからなる耐熱バイン
ダー２が均一に微細分散し、気孔率45％以内の構造とな
っている。金属水素化物粉末１の表面には、酸化物被膜
３が生成されていて、解離により発生する水素ガスの放
出を抑制することができる。酸化物は一般に水素透過が
少なく、バリヤー材として適している。耐熱バインダー
は、約700℃の高温まで安定であり、成形加工性に優れ
るので、成形体の機械的強度、寸法安定性等の熱的安定
性を与えるとともに、任意の形状に成形・加工すること
を可能にする。1). Molded product structure The molded product has a structure as schematically shown in the accompanying drawings. That is, a metal hydride powder having a size of 5 to 100 μm 1
The heat-resistant binder 2 made of calcium silicate having a size of 1 to 10 μm is uniformly finely dispersed, and the structure has a porosity of 45% or less. The oxide film 3 is formed on the surface of the metal hydride powder 1, and the release of hydrogen gas generated by dissociation can be suppressed. Oxides generally have low hydrogen permeation and are suitable as barrier materials. The heat-resistant binder is stable up to a high temperature of about 700 ° C and has excellent molding processability. Therefore, it gives thermal stability such as mechanical strength and dimensional stability of the molded product, and it can be molded and processed into any shape. To enable.
２）．化学組成 中性子減速材：金属水素化物 耐熱バインダー：珪酸カルシウム 例えば トバモライト： 5CaO・6SiO2・5H2O ゾノトライト： 6CaO・6SiO2・H2O 中性子減速材として含有する金属水素化物としては、
水素化チタン、水素化ジルコニウム、水素化イットリウ
ム、水素化ガドリニウム、水素化ユーロピウム、水素化
ハフニウム、水素化トリウム、水素化ウラン等の粉末が
あり、800℃まで水素の解離が少ないものである。これ
ら金属水素化物粉末の表面に酸化物被膜を生成させ、解
離により生じる水素ガスの放出を抑制する。生成方法と
しては、大気中あるいは酸素雰囲気中で金属水素化物の
原料粉末を加熱して表面を酸化することにより酸化被膜
を生成させる方法や、蒸着等の手段によりSiO2、ZrO2等
を被覆する方法がある。2). Chemical composition Neutron moderator: Metal hydride Heat resistant binder: Calcium silicate For example Tobermorite: 5CaO ・ 6SiO 2・ 5H 2 O Zonotorite: 6CaO ・ 6SiO 2・ H 2 O As a metal hydride contained as a neutron moderator,
There are powders of titanium hydride, zirconium hydride, yttrium hydride, gadolinium hydride, europium hydride, hafnium hydride, thorium hydride, uranium hydride, etc., and hydrogen dissociation is small up to 800 ° C. An oxide film is formed on the surface of these metal hydride powders to suppress release of hydrogen gas generated by dissociation. As the generation method, a method of generating an oxide film by heating the raw material powder of metal hydride in the air or an oxygen atmosphere to oxidize the surface, or a method such as vapor deposition is used to coat SiO 2 , ZrO 2, etc. There is a way.
耐熱バインダーとして含有する珪酸カルシウムは、例
えばトバモライト、ゾノトライト等がある。これらの珪
酸カルシウムは珪酸質粉末と石灰質粉末を原料として合
成することができ、その場合の珪酸質粉末と石灰質粉末
のCaO/SiO2モル比は、トバモライトの合成では0.6〜1.
0、ゾノトライトの合成では、0.8〜1.2が望ましい。Examples of calcium silicate contained as the heat-resistant binder include tobermorite and xonotlite. These calcium silicates can be synthesized by using siliceous powder and calcareous powder as raw materials, and in that case, the CaO / SiO 2 molar ratio of siliceous powder and calcareous powder is 0.6 to 1 in the synthesis of tobermorite.
0, 0.8 to 1.2 is desirable in the synthesis of xonotlite.
金属水素化物の添加量は、多ければ多いほど、その遮
蔽性能は大であるが、遮蔽材としての適性は、珪酸カル
シウム100重量部に対して、金属水素化物が800重量部を
超えると、成形材の作製が困難となる。また、遮蔽効果
を有効にするためには、少なくとも50重量部の金属水素
化物が必要である。さらに、成形材の強度を上げるため
に、必要に応じてガラス繊維、炭素繊維、金属ウイスカ
ー等の補強材の添加が可能である。The greater the amount of metal hydride added, the greater the shielding performance, but its suitability as a shielding material is that when metal hydride exceeds 800 parts by weight with respect to 100 parts by weight of calcium silicate, molding It becomes difficult to manufacture the material. In addition, at least 50 parts by weight of metal hydride is necessary for effective shielding effect. Further, in order to increase the strength of the molded material, it is possible to add a reinforcing material such as glass fiber, carbon fiber, or metal whisker, if necessary.
３）．成形プロセス 成形プロセスは、珪酸カルシウムの合成原料である珪
酸質粉末と石灰質粉末に、表面に酸化物被膜を形成した
金属水素化物の粉末を添加し、均一に混合する。この混
合粉末に対して、０〜50wt％の水を均一に添加した後、
プレス成形または型枠に充填し、高温・高圧水蒸気下で
反応硬化させて成形体を得る。成形体は、必要に応じて
機械加工し、遮蔽材として利用することができる。3). Molding Process In the molding process, powder of metal hydride having an oxide film formed on the surface is added to silicic acid powder and calcareous powder, which are raw materials for synthesizing calcium silicate, and they are mixed uniformly. After uniformly adding 0 to 50 wt% of water to this mixed powder,
Press molding or filling in a mold and reaction curing under high temperature and high pressure steam to obtain a molded body. The molded body can be machined as necessary and used as a shielding material.
〈実 施 例〉 １）．製造例 表１の配合表の試料No.1、２、３、４を得るために
は、原料を乾式で均一に混合し、粉体100wt％に対し水1
0wt％を加え均一に分散させる。その後、100kg/cm2の圧
力でプレス成形した後、オートクレーブ中で15kg/cm2の
圧力下で15時間養生し、試料を作製した。これらについ
て、物性値を測定した結果を表２に示す。<Practical example> 1). Production Example In order to obtain Sample Nos. 1, 2, 3, and 4 in the recipe of Table 1, raw materials are uniformly mixed in a dry method, and 100% by weight of powder is mixed with 1 part of water.
Add 0 wt% and disperse evenly. Then, after press-molding at a pressure of 100 kg / cm 2 , it was aged in the autoclave under a pressure of 15 kg / cm 2 for 15 hours to prepare a sample. Table 2 shows the results of measuring the physical properties of these materials.
２）．遮蔽性能評価例 核分裂スペクトル中性子源に対するSUS316と試料No.
1、２、３、４の遮蔽性能を評価した結果を表３に示
す。 2). Shielding performance evaluation example SUS316 and sample No. for fission spectrum neutron source
Table 3 shows the results of evaluating the shielding performance of 1, 2, 3, and 4.
この遮蔽性能評価例は、核分裂スペクトルの中性子源
を遮蔽材に接して配置し、線量当量率が、1000分の１
（10-3）、100万分の１（10-6）まで減衰するのに必要
な遮蔽材の厚さについて、SUS316の場合の厚さを１とし
て示したものである。 In this shielding performance evaluation example, the neutron source of fission spectrum is placed in contact with the shielding material, and the dose equivalent rate is 1/1000.
(10 -3 ), the thickness of the shielding material required to attenuate to one millionth (10 -6 ) is shown as 1 for SUS316.
〈発明の効果〉 １）．耐熱性に優れる。<Effect of Invention> 1). Excellent heat resistance.
耐熱性に優れる合金系の金属水素化物を原料とし、耐
熱バインダーにより成形することで、高温での使用が可
能である。By using an alloy-based metal hydride having excellent heat resistance as a raw material and molding with a heat-resistant binder, it can be used at high temperatures.
２）．任意の形状に成形・加工できる。2). Can be molded and processed into any shape.
中性子減速材を耐熱バインダーでくるんで成形する方
式のため、機械的強度のある遮蔽体として任意の形状に
成形することができる。Since the neutron moderator is formed by wrapping it in a heat-resistant binder, it can be formed in any shape as a shield having mechanical strength.
３）．成分とその配合率を変えることで遮蔽性能の設計
ができる。3). The shielding performance can be designed by changing the components and their blending ratio.
中性子減速材、耐熱バインダーの配合率を変えること
で、遮蔽性能を設計することができる。The shielding performance can be designed by changing the compounding ratio of the neutron moderator and the heat resistant binder.
４）．遮蔽体の薄肉化、軽量化 従来用いられてきたSUS316といったステンレス鋼に比
較して、格段に中性子遮蔽能力に優れ、かつ、密度の小
さい金属水素化物を高体積率で含有する遮蔽体を製造で
きるため、遮蔽体の大幅な薄肉化と軽量化が達成でき
る。4). Thinner and lighter weight of shields Compared to the conventionally used stainless steel such as SUS316, it is possible to manufacture shields that have significantly higher neutron shielding ability and a high density of metal hydride with a low density. Therefore, it is possible to significantly reduce the thickness and weight of the shield.
添付図面は本発明の遮蔽材の成形体構造概念図である。 １……金属水素化物 ２……耐熱バインダー（珪酸カルシウム） ３……酸化物被膜 The attached drawings are conceptual views of the structure of the molded body of the shielding material of the present invention. 1 ... Metal hydride 2 ... Heat-resistant binder (calcium silicate) 3 ... Oxide film
フロントページの続き (72)発明者 野村 茂雄 茨城県東茨城郡大洗町成田町4002番地 動 力炉・核燃料開発事業団大洗工学センター 内 (72)発明者 立辺 和明 茨城県東茨城郡大洗町成田町4002番地 動 力炉・核燃料開発事業団大洗工学センター 内 (72)発明者 鹿倉 栄 茨城県東茨城郡大洗町成田町4002番地 動 力炉・核燃料開発事業団大洗工学センター 内 (72)発明者 奥田 久志 茨城県石岡市大字柏原６―１ 株式会社ア スク研究開発本部中央研究所内 (72)発明者 原田 恵文 神奈川県横浜市鶴見区鶴見中央２丁目５番 ５号 株式会社アスク内 (72)発明者 香西 健一 茨城県石岡市大字柏原６―１ 株式会社ア スク研究開発本部中央研究所内Front page continuation (72) Shigeo Nomura Inventor Shigeo Nomura 4002 Narita-cho, Oarai-cho, Higashi-Ibaraki-gun, Ibaraki Power Reactor and Nuclear Fuel Development Corporation Oarai Engineering Center (72) Inventor Kazuaki Tatebe Oarai-cho, Higashi-Ibaraki-gun, Ibaraki Narita-cho 4002 Dynamic Reactor / Nuclear Fuel Development Corporation Oarai Engineering Center (72) Inventor Sakae Kakura 4002 Narita-cho Oarai-cho, Higashi-Ibaraki-gun, Ibaraki Oarai Engineering Center (72) Invention Person Hisashi Okuda 6-1 Kashiwara, Ishioka-shi, Ibaraki 6-1 Central Research Laboratory, Research and Development Division, Ask (72) Inventor Keifumi Harada 2-5-5, Tsurumi Chuo, Tsurumi-ku, Yokohama, Kanagawa ) Inventor Kenichi Kosai 6-1 Kashiwara, Ishioka-shi, Ibaraki 6-1 Ask Research Co., Ltd. Central Research Laboratory
Claims (1)
なる混合成形体であって、珪酸カルシウム100重量部に
対し、金属水素化物を50〜800重量部含有し、珪酸カル
シウムは珪酸質および石灰質のCaO/SiO2モル比が0.5〜
2.0の範囲であり、金属水素化物はTi、Zr、Ｙ、Gd、E
u、Hf、Th、Ｕのいずれかの金属で水素／金属原子比が
0.7以上の範囲であり、上記金属水素化物の微粉末表面
には酸化物被膜が生成されていて複合粉末となっている
ことを特徴とする耐熱高速中性子遮蔽材。1. A mixed compact comprising calcium silicate and a metal hydride powder, which contains 50 to 800 parts by weight of metal hydride to 100 parts by weight of calcium silicate. Calcium silicate is composed of siliceous and calcareous substances. CaO / SiO 2 molar ratio is 0.5 ~
The range is 2.0 and the metal hydrides are Ti, Zr, Y, Gd, E.
u / Hf / Th / U metal with hydrogen / metal atomic ratio
A heat-resistant fast neutron shielding material having a range of 0.7 or more, wherein an oxide film is formed on the surface of the fine metal hydride powder to form a composite powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2267756A JPH0827387B2 (en) | 1990-10-05 | 1990-10-05 | Heat-resistant fast neutron shielding material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2267756A JPH0827387B2 (en) | 1990-10-05 | 1990-10-05 | Heat-resistant fast neutron shielding material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04143696A JPH04143696A (en) | 1992-05-18 |
| JPH0827387B2 true JPH0827387B2 (en) | 1996-03-21 |
Family
ID=17449151
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2267756A Expired - Fee Related JPH0827387B2 (en) | 1990-10-05 | 1990-10-05 | Heat-resistant fast neutron shielding material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0827387B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8261832B2 (en) * | 2008-10-13 | 2012-09-11 | Shell Oil Company | Heating subsurface formations with fluids |
-
1990
- 1990-10-05 JP JP2267756A patent/JPH0827387B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04143696A (en) | 1992-05-18 |
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