JPH0134357B2 - - Google Patents
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- Publication number
- JPH0134357B2 JPH0134357B2 JP55157037A JP15703780A JPH0134357B2 JP H0134357 B2 JPH0134357 B2 JP H0134357B2 JP 55157037 A JP55157037 A JP 55157037A JP 15703780 A JP15703780 A JP 15703780A JP H0134357 B2 JPH0134357 B2 JP H0134357B2
- Authority
- JP
- Japan
- Prior art keywords
- rod
- neutron absorption
- neutron
- absorption rod
- control rod
- 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
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Classifications
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- 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
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- Monitoring And Testing Of Nuclear Reactors (AREA)
Description
【発明の詳細な説明】
〔発明の目的〕
（産業上の利用分野）
本発明は原子炉用制御棒に係り、特に炉心への
挿入を円滑に実施することができる原子炉用制御
棒に関する。DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a control rod for a nuclear reactor, and particularly to a control rod for a nuclear reactor that can be smoothly inserted into a reactor core.
（従来の技術）
従来の原子炉用制御棒は、一般に中性子吸収材
としてボロンカーバイト（B4C）粉末を理論密度
の約70％（比重約1.76ｇ／cm3）の密度で金属中空
棒に振動充てんして製作された中性子吸収棒を用
いて構成される。(Prior art) Conventional control rods for nuclear reactors are generally made of hollow metal rods using boron carbide (B 4 C) powder as a neutron absorbing material at a density of approximately 70% of the theoretical density (specific gravity approximately 1.76 g/cm 3 ). It is constructed using a neutron-absorbing rod made by filling vibrations in the neutron.
この制御棒を原子炉炉心に装荷して使用する
と、B4C中のボロン−10（Ｂ−10）が中性子の照
射をうけ、いわゆる（ｎ、α）反応によりヘリウ
ム（He）ガスを発生し、金属中空棒内の圧力を
上昇させるので、制御棒の機械的寿命は比較的短
かい。 When this control rod is loaded into the reactor core and used, boron-10 (B-10) in B 4 C is irradiated with neutrons and generates helium (He) gas through a so-called (n, α) reaction. , which increases the pressure within the metal hollow rod, so the mechanical life of the control rod is relatively short.
また中性子を吸収してＢ−10が減損すると、
B4Cの中性子吸収断面積が中性子の照射量に対し
て直線的に減少し、その結果中性子束レベルが上
昇するので、Ｂ−10の減損割合はＢ−10の残存量
が低下するにつれて加速度的に増大し、制御棒の
反応度価値も加速度的に低下し核的寿命も短くな
る。特に質量数が10であるＢ−10原子は中性子を
１回吸収するだけでHeガスを放出してLiに変換
され中性子吸収材としの寿命を終える。 Also, when B-10 is depleted by absorbing neutrons,
Since the neutron absorption cross section of B4C decreases linearly with the neutron irradiation dose, resulting in an increase in the neutron flux level, the depletion rate of B-10 accelerates as the remaining amount of B-10 decreases. The reactivity value of control rods also decreases at an accelerating rate, shortening their nuclear lifetime. In particular, a B-10 atom with a mass number of 10 absorbs a neutron just once, releases He gas, is converted to Li, and ends its life as a neutron absorber.
（発明が解決しようとする課題）
制御棒の寿命はこの機械的寿命と核的寿命のう
ち短い方で決定されるが、何れにしても比較的短
いので、頻繁に交換を要し、また交換に際して処
理を必要とする放射性廃棄物を大量に発生する欠
点がある。(Problem to be Solved by the Invention) The lifespan of a control rod is determined by the shorter of the mechanical life and the nuclear life, but since both are relatively short, they require frequent replacement, and The disadvantage is that a large amount of radioactive waste is generated, which requires treatment.
また粉末状の中性子吸収材を使用する場合は、
経時的に沈降圧密による吸収材粉末の偏位が生
じ、制御棒の中性子吸収能力が不均一になる問題
点がある。 In addition, when using powdered neutron absorbing material,
There is a problem in that the absorption material powder shifts over time due to sedimentation and consolidation, resulting in uneven neutron absorption capacity of the control rod.
本発明者等は前述した従来の制御棒の問題点に
鑑み、ヘリウムガスを発生せず、また中性子を数
回にわたつて吸収した場合においても中性子吸収
断面積の低下が少ない、核的寿命の長い核種（長
寿命型中性子吸収材）を充填した中性子吸収棒を
形成し、その中性子吸収棒を多数配列した制御棒
を開発した。 In view of the problems of the conventional control rods mentioned above, the present inventors have developed a control rod that does not generate helium gas and has a nuclear lifetime that does not reduce the neutron absorption cross section even when it absorbs neutrons several times. We formed a neutron absorption rod filled with long nuclides (long-life neutron absorption material) and developed a control rod with a large number of neutron absorption rods arranged.
上記の中性子吸収棒は、酸化ユーロピウム粉末
と酸化ハフニウム粉末との混合粉末を、中空金属
被覆管の一部または全長にわたつて充填して成る
ものである。 The above-mentioned neutron absorption rod is made by filling a part or the entire length of a hollow metal cladding tube with a mixed powder of europium oxide powder and hafnium oxide powder.
ところが、ユーロピウムは希土類であり高価な
材料であるため、コスト上難点があつた。また、
酸化ハフニウム粉末のみではB4Cより反応度価値
が低く、制御棒用の中性子吸収材としては不充分
である。 However, since europium is a rare earth element and an expensive material, there was a cost problem. Also,
Hafnium oxide powder alone has a lower reactivity value than B 4 C, and is insufficient as a neutron absorbing material for control rods.
これに対し、ハフニウムのソリツドメタル（む
き出し状態のメタル）により中性子吸収棒を形成
すれば、核的寿命を著しく延伸し、また価格上の
問題もなく反応度的にも充分なものとなるが、ハ
フニウムは硬く、剛性が大であると言う性質があ
り、前記のハフニウム製中性子吸収棒を使用した
制御棒には次のような問題を生じる。 On the other hand, if the neutron absorption rod is made of hafnium solid metal (exposed metal), the nuclear lifetime will be significantly extended, and the reactivity will be sufficient without any cost problems. Hafnium has the property of being hard and having high rigidity, and the following problems arise in control rods using the above-mentioned hafnium neutron absorption rods.
すなわち、複数本の吸収棒をブレード内に収容
した場合、制御棒全体の剛性がかなり高くなる。
そのため、沸騰水型原子炉の炉心を形成する４体
１組の燃料集合体間の狭い十字状空隙に制御棒を
挿入するに際し、制御棒と燃料集合体とが接触し
た場合に、両者のなじみが少なく、制御棒挿入時
に制御棒が燃料集合体を突上げるおそれがある。
その突き上げによる損傷等を防止するため、原子
炉のスクラム時の制御棒挿入速度を下げることが
必要となり、原子炉の緊急停止が円滑かつ迅速に
実施することができないという問題点がある。 That is, when a plurality of absorption rods are housed in the blade, the rigidity of the entire control rod becomes considerably high.
Therefore, when a control rod is inserted into a narrow cross-shaped gap between a set of four fuel assemblies that form the core of a boiling water reactor, if the control rods and fuel assemblies come into contact with each other, there is There is a risk that the control rod will push up the fuel assembly when the control rod is inserted.
In order to prevent damage caused by the thrusting, it is necessary to reduce the control rod insertion speed during scram of the reactor, which poses a problem in that an emergency shutdown of the reactor cannot be carried out smoothly and quickly.
また、剛性を低下させるためには、中性子吸収
棒を細い径で形成する必要があり、必然的に反応
度の低下を招いていた。 Furthermore, in order to reduce the rigidity, it is necessary to form the neutron absorption rod with a small diameter, which inevitably leads to a reduction in reactivity.
本発明は、上述した事情を考慮してなされたも
ので、ハフニウムのソリツドメタルにより形成し
た中性子吸収棒の軸に垂直方向の剛性を小さく
し、炉心への挿入を円滑かつ迅速に行ない得る原
子炉用制御棒を提供することを目的とする。 The present invention has been made in consideration of the above-mentioned circumstances, and is a neutron absorbing rod made of a solid metal of hafnium, which has a reduced rigidity in the direction perpendicular to the axis, and is used for a nuclear reactor that can be smoothly and quickly inserted into the reactor core. The purpose is to provide control rods.
本発明の他の目的は、中性子吸収材の圧密沈降
による中性子吸収能力の不均一を生じることがな
く、長寿命を有する原子炉用制御棒を提供するこ
とにある。 Another object of the present invention is to provide a control rod for a nuclear reactor that does not cause unevenness in neutron absorption capacity due to consolidation sedimentation of the neutron absorbing material and has a long life.
（課題を解決するための手段）
本発明に係る原子炉用制御棒は、断面が十字形
状の中央タイロツドの各突出部に深いＵ字状断面
を有するシースを固着して十字形状のブレードを
形成し、各シース内に中性子吸収棒を配設した原
子炉用制御棒において、上記中性子吸収棒を、ハ
フニウムのソリツドメタルで形成するとともに、
中性子吸収棒は、その軸方向に間隔をおいて、軸
直角方向に変形し易い部分を形成して構成され
る。
(Means for Solving the Problems) A control rod for a nuclear reactor according to the present invention forms a cross-shaped blade by fixing a sheath having a deep U-shaped cross section to each protrusion of a central tie rod having a cross-shaped cross section. In a control rod for a nuclear reactor in which a neutron absorption rod is arranged in each sheath, the neutron absorption rod is formed of a solid hafnium metal, and
The neutron absorption rod is configured by forming portions that are easily deformed in the direction perpendicular to the axis at intervals in the axial direction.
（作用）
上記構成に係る原子炉用制御棒によれば、中性
子吸収棒の軸方向に間隔をおいて、軸直角方向に
変形し易い部分を形成し、軸に垂直方向の剛性を
小さくしているため、原子炉用制御棒と燃料集合
体とがなじみ易く、挿入時等において両者が接触
した場合においても、原子炉用制御棒のブレード
が柔軟に軸直角方向に変形して逃げることができ
るので、燃料集合体を突き上げたり、損傷させる
おそれが少なくなる。したがつて原子炉をより安
全かつ迅速に緊急停止することが可能となる。(Function) According to the control rod for a nuclear reactor having the above configuration, portions that are easily deformed in the direction perpendicular to the axis are formed at intervals in the axial direction of the neutron absorption rod, and the rigidity in the direction perpendicular to the axis is reduced. This allows the reactor control rods and fuel assembly to fit together easily, and even if they come into contact during insertion, the blades of the reactor control rods can flexibly deform in the direction perpendicular to the axis and escape. Therefore, there is less risk of the fuel assembly being pushed up or damaged. Therefore, it becomes possible to more safely and quickly make an emergency shutdown of the nuclear reactor.
また、中性子吸収棒を、ハフニウム（天然ハフ
ニウムを含む。）のソリツドメタルで形成してい
るため、粉末状中性子吸収材を充填した従来の中
性子吸収棒のように経時的に沈降圧密を引き起こ
すことがなく、軸方向の中性子吸収能力が不均一
になることがない。 In addition, because the neutron absorption rod is made of solid hafnium metal (including natural hafnium), it does not cause sedimentation and consolidation over time, unlike conventional neutron absorption rods filled with powdered neutron absorption material. , the neutron absorption capacity in the axial direction does not become non-uniform.
ここでハフニウムとしては一般に天然ハフニウ
ムが好適である。天然ハフニウムには、分離精製
が困難なジルコニウム（Zr）等の不純物金属元
素が含有されており、その含有量は原鉱石の産地
によつて異なる。 Here, natural hafnium is generally preferred as hafnium. Natural hafnium contains impurity metal elements such as zirconium (Zr) that are difficult to separate and refine, and the content varies depending on the origin of the raw ore.
またソリツドメタルとは、被覆材で被覆するこ
となく、冷却材に直接接触するようなむき出し状
態のメタルをいう。 Solid metal refers to exposed metal that is not covered with a covering material and is in direct contact with the coolant.
また中性子吸収棒の材料であるハフニウムは、
中性子吸収断面積が大きな同位体を多数形成する
核的特性を有しているため、多数回にわたつて連
続的に中性子を吸収することが可能である。その
結果、常に高い中性子吸収能力分布を長期間に渡
り保持することができ、制御棒の寿命を大幅に延
ばすことができる。 In addition, hafnium, which is a material for neutron absorption rods,
Because it has the nuclear property of forming a large number of isotopes with large neutron absorption cross sections, it is possible to continuously absorb neutrons many times. As a result, a consistently high neutron absorption capacity distribution can be maintained for a long period of time, and the life of the control rod can be significantly extended.
（実施例）
以下、本発明の一実施例について添付図面を参
照して説明する。第１図は本発明に係る原子炉用
制御棒の一実施例を示す斜視図であり、第２図は
第１図における−矢視断面図である。(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of a control rod for a nuclear reactor according to the present invention, and FIG. 2 is a sectional view taken along the - arrow in FIG.
本実施例に係る原子炉用制御棒は、断面が十字
形状の中央タイロツド１の各突出部に、深いＵ字
状断面を有するシース２を固着して、十字形状の
ブレードを形成し、各シース２内にシース全長に
及ぶ中性子吸収棒３を配設した原子炉用制御棒に
おいて、上記中性子吸収棒を、ハフニウム（天然
ハフニウムを含む。）のソリツドメタルで形成す
るとともに、中性子吸収棒の軸方向に間隔をおい
て、軸直角方向に変形し易い部分を形成して構成
される。また各シース２には、炉心を流れる減速
材の一部をシース２内に流通させるための、減速
材流出入孔６が多数穿設されている。 In the nuclear reactor control rod according to this embodiment, a sheath 2 having a deep U-shaped cross section is fixed to each protrusion of a central tie rod 1 having a cross-shaped cross section to form a cross-shaped blade. In a control rod for a nuclear reactor, in which a neutron absorption rod 3 extending over the entire length of the sheath is disposed inside the neutron absorption rod 2, the neutron absorption rod 3 is formed of a solid metal of hafnium (including natural hafnium), and It is constructed by forming portions that are easily deformable in the direction perpendicular to the axis at intervals. Further, each sheath 2 is provided with a large number of moderator inflow/outflow holes 6 for allowing a portion of the moderator flowing through the core to flow into the sheath 2 .
また、上記中性子吸収棒３は、中性子吸収能力
が長期間維持される長寿命型ハフニウムのソリツ
ドメタルで形成され、第２図に示すように制御棒
の軸方向に平行に多数配設される。ここに、ソリ
ツドメタルとは被覆材で被覆することなく、むき
出し状態のメタルをいう。また各中性子吸収棒３
の軸方向には適宜間隔をおいて、軸直角方向に変
形し易い部分４が形成されている。この変形し易
い部分４は第３図に示すように、中性子吸収棒３
の外周に形成した周溝４ａで形成される。この周
溝４ａは中性子吸収棒３の中心軸に向つて連続的
に緩やかな曲率をもつて変化する表面を有し、中
性子吸収棒３の外径を狭める形状とされている。 The neutron absorption rods 3 are made of a long-life hafnium solid metal whose neutron absorption ability is maintained for a long period of time, and are arranged in large numbers parallel to the axial direction of the control rod, as shown in FIG. Here, solid metal refers to metal that is exposed without being covered with a covering material. Also, each neutron absorption rod 3
Portions 4 that are easily deformable in the direction perpendicular to the axis are formed at appropriate intervals in the axial direction. As shown in FIG. 3, this easily deformable portion 4 is
It is formed by a circumferential groove 4a formed on the outer periphery of. This circumferential groove 4a has a surface that continuously changes with a gentle curvature toward the central axis of the neutron absorption rod 3, and is shaped to narrow the outer diameter of the neutron absorption rod 3.
上記構成の中性子吸収棒３は、周溝４ａの部分
で曲り易く屈曲自在となる。そして軸に垂直方向
の剛性を小となし得る。従つて上記中性子吸収棒
３を使用した制御棒の軸直角方向の剛性も小とな
る。その結果制御棒の挿入時に、燃料集合体と制
御棒のブレードとが接触した場合においても、ブ
レードが柔軟に軸直角方向に変形して逃げること
ができるので、燃料集合体を突き上げるおそれが
ない。 The neutron absorption rod 3 having the above structure is easily bendable at the circumferential groove 4a. And the rigidity in the direction perpendicular to the axis can be made small. Therefore, the rigidity of the control rod using the neutron absorption rod 3 in the direction perpendicular to the axis is also small. As a result, even if the fuel assembly and the blade of the control rod come into contact when inserting the control rod, the blade can flexibly deform in the direction perpendicular to the axis and escape, so there is no risk of pushing up the fuel assembly.
従つて緊急停止（原子炉スクラム）時におけ
る、制御棒の挿入速度を上昇させることが可能と
なり、原子炉の緊急停止をより迅速かつ円滑に実
施することができる。 Therefore, it is possible to increase the control rod insertion speed during emergency shutdown (reactor scram), and emergency shutdown of the reactor can be performed more quickly and smoothly.
また中性子吸収棒３は粉末状の中性子吸収材で
はなく、固体状のソリツドメタルで形成している
ため、中性子吸収材としての密度が高く、さらに
制御棒としての寿命が長く、また中性子吸収材の
沈降偏位による中性子吸収能力の不均一も生じな
い。 In addition, since the neutron absorption rod 3 is made of solid metal rather than powdered neutron absorption material, it has a high density as a neutron absorption material and has a long life as a control rod. Non-uniformity in neutron absorption capacity due to deviation does not occur.
特に本実施例においては、中性子吸収断面積が
大きな同位体を多数形成する核的特性を有するハ
フニウムで中性子吸収棒を形成しており、ハフニ
ウムは多数回にわたつて連続的に中性子を吸収す
ることが可能である。その結果、制御棒の寿命を
大幅に延ばすことができる。 In particular, in this example, the neutron absorption rod is made of hafnium, which has the nuclear property of forming many isotopes with large neutron absorption cross sections, and hafnium absorbs neutrons continuously many times. is possible. As a result, the life of the control rods can be significantly extended.
一方従来の中性子吸収材でるB4Cのボロン10
は、１回の中性子吸収によつてリチウム（Li）に
変換され、以後の中性子吸収能力は喪失してしま
うため寿命が短かい。 On the other hand, conventional neutron absorbing material B 4 C boron 10
is converted to lithium (Li) by one neutron absorption and loses its neutron absorption ability thereafter, so its lifespan is short.
ちなみに従来のB4Cを理論密度の70％で金属管
に充填した比重1.76の中性子吸収棒と同寸法を有
するハフニウム製中性子吸収棒は、B4Cを充填し
て形成した中性子吸収棒の４倍程度の長寿命を有
することが実証されている。 By the way, a hafnium neutron absorption rod with the same dimensions as a conventional neutron absorption rod with a specific gravity of 1.76, which is made by filling a metal tube with B 4 C at 70% of its theoretical density, is 4. It has been proven that it has a lifespan that is about twice as long.
次に本発明の他の実施例について第４図を参照
して説明する。 Next, another embodiment of the present invention will be described with reference to FIG.
本実施例に係る原子炉用制御棒は、前記実施例
において形成した周溝４ａを中心軸に達するまで
深く形成し、実質的に複数の中性子吸収棒要素５
を連設した構造としている。すなわち、本実施例
の原子炉用制御棒はシース全長より短尺な中性子
吸収棒要素５を軸方向に複数個連設してシース全
長に及ぶ中性子吸収棒３を形成し、隣接する中性
子吸収棒要素５の連設部４ｂを変形し易い部分４
として構成したものである。 In the nuclear reactor control rod according to this embodiment, the circumferential groove 4a formed in the embodiment described above is formed deep until it reaches the central axis, and substantially a plurality of neutron absorbing rod elements 5
The structure has a series of That is, in the nuclear reactor control rod of this embodiment, a plurality of neutron absorption rod elements 5 shorter than the entire sheath length are arranged in series in the axial direction to form a neutron absorption rod 3 extending over the entire sheath length, and adjacent neutron absorption rod elements Portion 4 where the continuous portion 4b of No. 5 is easily deformed
It is constructed as follows.
本実施例によれば軸方向に隣接した各中性子吸
収棒要素５は相互に独立して軸直角方向に動くこ
とが可能であるため、中性子吸収棒３全体として
の剛性は極めて少なく、この中性子吸収棒３を収
容した制御棒の軸直角方向の剛性は小となり、第
３図に示す中性子吸収棒３を使用したものと同様
な効果を得ることができる。 According to this embodiment, the neutron absorption rod elements 5 adjacent to each other in the axial direction can move independently of each other in the direction perpendicular to the axis, so the rigidity of the neutron absorption rod 3 as a whole is extremely small, and the neutron absorption The rigidity of the control rod containing the rod 3 in the direction perpendicular to the axis is small, and the same effect as that using the neutron absorption rod 3 shown in FIG. 3 can be obtained.
なお、沸騰水型原子炉用制御棒において、中性
子吸収棒３は深いＵ字状に形成したシース２内に
収容されているため、軸方向に複数の要素に切断
分割しても、その中性子吸収棒３の各要素５，５
は相互に配設位置を保持し得る。 In addition, in the control rod for a boiling water reactor, the neutron absorption rod 3 is housed in the sheath 2 formed in a deep U-shape, so even if it is cut and divided into multiple elements in the axial direction, the neutron absorption rod 3 is Each element of bar 3 5,5
can maintain their position relative to each other.
また前記の周溝４ａまたは連設部４ｂは中性子
吸収棒３の全長にわたり10箇所前後配設すること
が適当である。 Further, it is appropriate that the circumferential grooves 4a or the continuous portions 4b are provided at approximately 10 locations over the entire length of the neutron absorbing rod 3.
さらに従来、中性子吸収棒としてソリツドメタ
ルを使用する場合、制御棒のしなやかさを確保す
るために細いソリツドメタルしか使用できず、反
応度が低下しがちであつたが、本実施例の構造を
採用することにより、太いソリツドメタルを使用
することも可能となる。すなわち、円滑な挿入を
可能とするしなやかさを確保するとともに反応度
価値をも高めることができる。 Furthermore, in the past, when solid metal was used as a neutron absorption rod, only thin solid metal could be used to ensure the flexibility of the control rod, and the reactivity tended to decrease.However, the structure of this example is adopted. This makes it possible to use thick solid metal. In other words, it is possible to ensure flexibility that enables smooth insertion, and also to increase reactivity value.
以上説明の通り本発明に係る原子炉用制御棒に
よれば、中性子吸収棒の軸方向に間隔をおいて、
軸直角方向に変形し易い部分を形成し、軸直角方
向の剛性を低減しているため、原子炉用制御棒と
燃料集合体とがなじみ易く、挿入時等において両
者が接触した場合においても、原子炉用制御棒の
ブレードが柔軟に軸直角方向に変形して逃げるこ
とができるので、燃料集合体を突き上げたり、損
傷させるおそれが少なくなる。したがつて原子炉
をより安全かつ迅速に緊急停止することが可能と
なる。
As explained above, according to the nuclear reactor control rod according to the present invention, at intervals in the axial direction of the neutron absorption rod,
By forming a part that is easily deformed in the direction perpendicular to the axis and reducing the rigidity in the direction perpendicular to the axis, the reactor control rod and the fuel assembly easily fit together, and even if they come into contact during insertion, etc. Since the blades of the reactor control rods can flexibly deform and escape in the direction perpendicular to the axis, there is less risk of them pushing up or damaging the fuel assembly. Therefore, it becomes possible to more safely and quickly make an emergency shutdown of the nuclear reactor.
また、中性子吸収棒を、ハフニウムのソリツド
メタルで形成しているため、粉末状中性子吸収材
を充填した従来の中性子吸収棒のように経時的に
沈降圧密を引き起し、軸方向の中性子吸収能力が
不均一になることがなく、常に高い吸収能力分布
を長期間に渡り保持することができる。 In addition, because the neutron absorption rod is made of solid hafnium metal, it causes sedimentation and consolidation over time, unlike conventional neutron absorption rods filled with powdered neutron absorption material, which reduces the neutron absorption capacity in the axial direction. It does not become non-uniform and can maintain a consistently high absorption capacity distribution for a long period of time.
第１図は本発明に係る原子炉用制御棒の一実施
例を示す斜視図、第２図は第１図における−
矢視断面図、第３図は中性子吸収棒の正面図、第
４図は中性子吸収棒の他の実施例を示す正面図で
ある。
１……中央タイロツド、２……シース、３……
中性子吸収棒、４……変形し易い部分、４ａ……
周溝、４ｂ……連設部、５……中性子吸収棒要
素、６……減速材流出入孔。
FIG. 1 is a perspective view showing one embodiment of a control rod for a nuclear reactor according to the present invention, and FIG. 2 is a −
3 is a front view of the neutron absorption rod, and FIG. 4 is a front view showing another embodiment of the neutron absorption rod. 1...Central tie rod, 2...Sheath, 3...
Neutron absorption rod, 4... Easily deformable part, 4a...
Circumferential groove, 4b... Continuous portion, 5... Neutron absorption rod element, 6... Moderator inflow/outflow hole.
Claims (1)
に深いＵ字状断面を有するシースを固着して十字
形状のブレードを形成し、各シース内に中性子吸
収棒を配設した原子炉用制御棒において、上記中
性子吸収棒を、ハフニウムのソリツドメタルで形
成するとともに、中性子吸収棒は、その軸方向に
間隔をおいて、軸直角方向に変形し易い部分を形
成したことを特徴とする原子炉用制御棒。 ２ 変形し易い部分は中性子吸収棒の外周に形成
した周溝である特許請求の範囲第１項記載の原子
炉用制御棒。 ３ 中性子吸収棒は、シース全長より短尺な中性
子吸収棒要素を軸方向に複数連設して形成され、
隣接する中性子吸収棒要素の連接部を変形し易い
部分としたことを特徴とする特許請求の範囲第１
項記載の原子炉用制御棒。[Claims] 1. A sheath having a deep U-shaped cross section is fixed to each protrusion of a central tie rod having a cross-shaped cross section to form a cross-shaped blade, and a neutron absorption rod is disposed within each sheath. The control rod for a nuclear reactor is characterized in that the neutron absorption rod is formed of solid hafnium metal, and the neutron absorption rod has portions that are easily deformed in the direction perpendicular to the axis at intervals in the axial direction. Control rods for nuclear reactors. 2. The control rod for a nuclear reactor according to claim 1, wherein the easily deformable portion is a circumferential groove formed on the outer periphery of the neutron absorption rod. 3. The neutron absorption rod is formed by axially arranging a plurality of neutron absorption rod elements shorter than the total length of the sheath,
Claim 1, characterized in that the connecting portion of adjacent neutron absorbing rod elements is a portion that is easily deformed.
Control rods for nuclear reactors as described in Section 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55157037A JPS5780590A (en) | 1980-11-10 | 1980-11-10 | Nuclear reactor control rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55157037A JPS5780590A (en) | 1980-11-10 | 1980-11-10 | Nuclear reactor control rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5780590A JPS5780590A (en) | 1982-05-20 |
| JPH0134357B2 true JPH0134357B2 (en) | 1989-07-19 |
Family
ID=15640807
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55157037A Granted JPS5780590A (en) | 1980-11-10 | 1980-11-10 | Nuclear reactor control rod |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5780590A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5780591A (en) * | 1980-11-10 | 1982-05-20 | Nippon Atomic Ind Group Co | Nuclear reactor control rod |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6051071B2 (en) * | 1978-06-16 | 1985-11-12 | 株式会社日立製作所 | Control rod for nuclear reactor |
-
1980
- 1980-11-10 JP JP55157037A patent/JPS5780590A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5780590A (en) | 1982-05-20 |
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