JPH0115839B2 - - Google Patents
Info
- Publication number
- JPH0115839B2 JPH0115839B2 JP55157038A JP15703880A JPH0115839B2 JP H0115839 B2 JPH0115839 B2 JP H0115839B2 JP 55157038 A JP55157038 A JP 55157038A JP 15703880 A JP15703880 A JP 15703880A JP H0115839 B2 JPH0115839 B2 JP H0115839B2
- Authority
- JP
- Japan
- Prior art keywords
- rod
- absorption
- protrusion
- shaped
- neutron
- 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
Links
- 238000010521 absorption reaction Methods 0.000 claims description 33
- 229910052735 hafnium Inorganic materials 0.000 claims description 10
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 239000007787 solid Substances 0.000 claims description 4
- 229910000925 Cd alloy Inorganic materials 0.000 claims description 2
- NCOPCFQNAZTAIV-UHFFFAOYSA-N cadmium indium Chemical compound [Cd].[In] NCOPCFQNAZTAIV-UHFFFAOYSA-N 0.000 claims 1
- 229910052709 silver Inorganic materials 0.000 claims 1
- 239000004332 silver Substances 0.000 claims 1
- 239000000446 fuel Substances 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 238000003780 insertion Methods 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 2
- CJNBYAVZURUTKZ-UHFFFAOYSA-N hafnium(iv) oxide Chemical compound O=[Hf]=O CJNBYAVZURUTKZ-UHFFFAOYSA-N 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910052580 B4C Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- BCEYEWXLSNZEFA-UHFFFAOYSA-N [Ag].[Cd].[In] Chemical compound [Ag].[Cd].[In] BCEYEWXLSNZEFA-UHFFFAOYSA-N 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- 229910001940 europium oxide Inorganic materials 0.000 description 1
- AEBZCFFCDTZXHP-UHFFFAOYSA-N europium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Eu+3].[Eu+3] AEBZCFFCDTZXHP-UHFFFAOYSA-N 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 235000013372 meat Nutrition 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 239000002901 radioactive waste Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 239000000126 substance 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
- 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】 本発明は原子炉の制御棒に関する。[Detailed description of the invention] The present invention relates to control rods for nuclear reactors.
原子炉の制御棒はボロンカーバイト（B4C）粉
末を理論密度の約70％（比重約1.76ｇ／cm2）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。この制御棒を原子
炉々心に装荷して使用すると、B4C中のボロンー
10（Ｂ−10）が中性子の照射をうけ、いわゆる
（ｎ、ａ）反応によりヘリウム（He）ガスを発生
し、金属管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。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。制御棒の寿命はこの
機械的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、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。 The control rods of the nuclear reactor are neutron absorbing rods made by vibrating and filling hollow metal rods with boron carbide (B 4 C) powder at a density of approximately 70% of the theoretical density (specific gravity approximately 1.76 g/cm 2 ). It consists of When this control rod is loaded into the core of a nuclear reactor and used, the boron in B 4 C
10 (B-10) is irradiated with neutrons and generates helium (He) gas through the so-called (n, a) reaction, increasing the pressure inside the metal tube, so the mechanical life of the control rod is relatively short. . In addition, when B-10 is depleted by absorbing neutrons, the neutron absorption cross section of B4C decreases linearly with respect to the neutron irradiation dose, and as a result, the neutron flux level increases, so the depletion of B-10 The ratio increases at an accelerating rate as the remaining amount of B-10 decreases, the reactivity value of the control rod also decreases at an accelerating rate, and the nuclear lifetime also shortens. The life of a control rod is determined by the shorter of the mechanical and nuclear lives.
In any case, since they are relatively short, they have the disadvantage of generating a large amount of radioactive waste that must be disposed of when replaced.
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、また中性子を吸
収して生成された核種が中性子吸収断面積の大き
くなる核的寿命の長い核種により中性子吸収棒を
形成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 discovered that they do not generate helium gas, and the nuclides produced by absorbing neutrons have a long nuclear lifetime and have a large neutron absorption cross section. A control rod with an absorption rod was developed.
前記の吸収棒は、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金属管の一部また
は全長にわたつて充填して成るものである。 The above-mentioned absorption rod is made by filling a part or the entire length of a metal 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, europium is a rare earth element and is an expensive material, which poses a cost problem. Further, hafnium oxide powder alone has low reactivity value 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によ
り中性子吸収棒を形成すれば、価格上問題もなく
反応度的にも充分なものとなるが、ハフニウムは
硬く、密度が大きいので前記の中性子吸収棒を使
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, there will be no cost problems and the reactivity will be sufficient, but hafnium is hard and has a high density, so the control using the neutron absorption rod described above is The following problems arise with the rod.
すなわち、複数本の吸収棒をブレート内に収容
した制御棒の剛性がかなり高くなり、燃料集合体
間の十字状空隙に挿入するに際し、制御棒と燃料
集合体とが接触すると、燃料集合体を突上げるお
それがある。その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
緊急停止がし難くなる。 In other words, the rigidity of a control rod with multiple absorption rods housed in the plate becomes considerably high, and when the control rod and the fuel assembly come into contact with each other when inserted into the cross-shaped gap between the fuel assemblies, the fuel assembly There is a risk of overturning. Therefore, it is necessary to reduce the control rod insertion speed during reactor scram, making it difficult to make an emergency shutdown of the reactor.
さらにハフニウムは密度が大であるため、制御
棒が重くなり制御棒駆動機構を強化する必要があ
る。 Furthermore, hafnium has a high density, making the control rods heavier and requiring a stronger control rod drive mechanism.
また、ハフニウムは共鳴吸収物質であり、その
吸収能力は中性子吸収棒の表面積が大きい程大き
い。 Furthermore, hafnium is a resonance absorbing substance, and its absorption capacity increases as the surface area of the neutron absorption rod increases.
本発明は上記の事情に基きなされたもので、中
性子の共鳴吸収割合を増大させるとともに、減肉
軽量化を図り、さらに軸と直角方向の剛性を低減
させることができる原子炉用制御棒を得ることを
目的とする。 The present invention has been made based on the above-mentioned circumstances, and provides a control rod for a nuclear reactor that can increase the resonance absorption rate of neutrons, reduce the thickness and reduce the weight, and further reduce the rigidity in the direction perpendicular to the axis. The purpose is to
本発明においては、ハフニウムによる中性子吸
収が共鳴吸収として特徴づけられることに着目
し、棒状ハフニウムの外表面に高い密度で突條を
設けて表面積を増大させ、中性子の共鳴吸収割合
を増大させながら減肉軽量化し、ひいては軸と直
角方向の剛性を低減させている。 In the present invention, we focused on the fact that neutron absorption by hafnium is characterized as resonance absorption, and by providing protrusions with a high density on the outer surface of rod-shaped hafnium to increase the surface area, we increase the resonance absorption rate of neutrons while reducing the This reduces the weight of the meat, which in turn reduces the rigidity in the direction perpendicular to the shaft.
第１図、第２図は本発明の一実施例を示してい
る。細長いＵ字状シース１内には中性子吸収棒２
が収容され、各シースは十字状のタイロツド３に
それぞれ取付けられ十字状のブレードを形成して
いる。 1 and 2 show an embodiment of the present invention. Inside the elongated U-shaped sheath 1 is a neutron absorption rod 2.
are housed, and each sheath is attached to a cross-shaped tie rod 3 to form a cross-shaped blade.
而して、ハフニウムソリツドメタルから成る中
性子吸収棒２の周面には、第３図に示す如く半径
方向外方に突出する螺旋状の突條４が軸方向のほ
ぼ全長にわたつて設けてある。上記の如く突條を
設けては、その突条の径と同一の径の丸棒状の吸
収棒より軸に直角方向の剛性は小となる。また、
表面積も大きくなる。 As shown in FIG. 3, the neutron absorbing rod 2 made of hafnium solid metal is provided with a spiral protrusion 4 projecting outward over almost its entire axial length on the circumferential surface thereof. be. When a protrusion is provided as described above, the rigidity in the direction perpendicular to the axis is smaller than that of a round bar-shaped absorption rod having the same diameter as the protrusion. Also,
The surface area also increases.
前記の如く剛性が小さくなるため、これを使用
して構成した制御棒の軸に直角方向の剛性も小さ
くなり、変形し易く燃料集合体と接触してもそれ
を突上げるおそれはない。また、そのため緊急挿
入時の挿入速度を上げることができ、原子炉の緊
急停止がやり易くなる。 As described above, since the rigidity is reduced, the rigidity in the direction perpendicular to the axis of a control rod constructed using the control rod is also reduced, so that it is easily deformed and there is no risk of it being pushed up even if it comes into contact with the fuel assembly. Furthermore, it is possible to increase the insertion speed during emergency insertion, making it easier to perform an emergency shutdown of the reactor.
さらにハフニウムによる中性子吸収は共鳴吸収
であり、その吸収能力は中性子吸収棒の表面積が
大きい程大きいので、前記の如く突條を設けるこ
とにより表面積を単なる丸棒より増大させ吸収能
力を向上させることができる。しかも、中性子吸
収棒の体積従つてその重量は小とされるので、制
御棒を軽量化することができ制御棒駆動機構を特
に強化する必要はない。 Furthermore, neutron absorption by hafnium is resonance absorption, and its absorption capacity increases as the surface area of the neutron absorption rod increases, so by providing a protrusion as described above, the surface area can be increased compared to a simple round rod, and the absorption capacity can be improved. can. Moreover, since the volume and weight of the neutron absorption rod are small, the weight of the control rod can be reduced and there is no need to particularly strengthen the control rod drive mechanism.
第４図Ａ，Ｂは本発明の他の実施例を示す。第
４図Ａに示したのは、中性子吸収棒２に軸方向に
分布して円周方向突条４′を設けたものであり、
第４図Ｂに示したのは前記突条４′に円周方向に
分布して軸方向切欠５を複数箇設けたものであ
る。これらの実施例によつても第３図のものと同
様の作用効果が得られる。 4A and 4B show other embodiments of the invention. What is shown in FIG. 4A is a neutron absorption rod 2 provided with circumferential protrusions 4' distributed in the axial direction.
What is shown in FIG. 4B is one in which the protrusion 4' is provided with a plurality of axial notches 5 distributed in the circumferential direction. These embodiments also provide the same effects as those shown in FIG. 3.
なお、本発明は前記実施例のみに限定されな
い。 Note that the present invention is not limited to the above embodiments.
例えば、銀−インジウム−カドミウム（Ag−
In−Ca）合金を使用した中性子吸収棒を装填し
た制御棒にも適用し得る。Ag−In−Cd合金もハ
フニウムソリツドメタルと同様に中性子吸収にお
ける共鳴吸収の割合が高い。 For example, silver-indium-cadmium (Ag-
It can also be applied to control rods loaded with neutron absorption rods using In-Ca) alloys. Like hafnium solid metal, Ag-In-Cd alloy also has a high proportion of resonance absorption in neutron absorption.
また、第３図の螺旋状突條を有する吸収棒を使
用した場合において、隣接した吸収棒を互いに逆
ピツチのものを使用すれば、吸収棒配列を粗にす
ることができ、同ピツチのものとすれば密にする
ことができる。 In addition, when using absorption rods with spiral protrusions as shown in Fig. 3, if adjacent absorption rods are used with opposite pitches, the arrangement of the absorption rods can be made coarser. If you do this, you can keep it secret.
第１図は本発明一実施例の斜視図、第２図はそ
の−線における断面図、第３図、第４図Ａ，
Ｂはそれぞれ中性子吸収棒の正面図である。
１……シース、２……中性子吸収棒、４，４′
……突條。
Fig. 1 is a perspective view of one embodiment of the present invention, Fig. 2 is a sectional view taken along the - line, Fig. 3, Fig. 4 A,
B is a front view of each neutron absorption rod. 1...sheath, 2...neutron absorption rod, 4,4'
...It's sudden.
Claims (1)
られ、各シース内に中性子吸収における共鳴吸収
割合が高いハフニウムソリツドメタルおよび銀−
インジウム−カドミウム合金のうち少なくとも一
方からなる中性子吸収棒が収容され、その棒材表
面積を増大させるように棒材周面に半径方向外方
に突出する突條が軸方向にほぼ全長にわたつて形
成されたことを特徴とする原子炉用制御棒。 ２ 前記突條を螺旋状とした特許請求の範囲第１
項記載の原子炉用制御棒。 ３ 前記突條を円周方向突條とした特許請求の範
囲第１項記載の原子炉用制御棒。[Claims] 1. A U-shaped sheath is attached to the cross-shaped tie rod, and each sheath contains hafnium solid metal and silver, which have a high resonance absorption rate in neutron absorption.
A neutron absorption rod made of at least one of an indium-cadmium alloy is housed, and a projection extending radially outward is formed on the circumferential surface of the rod over almost the entire length in the axial direction so as to increase the surface area of the rod. A nuclear reactor control rod characterized by: 2 Claim 1 in which the protrusion is spiral-shaped
Control rods for nuclear reactors as described in Section 1. 3. The control rod for a nuclear reactor according to claim 1, wherein the protrusion is a circumferential protrusion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55157038A JPS5780591A (en) | 1980-11-10 | 1980-11-10 | Nuclear reactor control rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55157038A JPS5780591A (en) | 1980-11-10 | 1980-11-10 | Nuclear reactor control rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5780591A JPS5780591A (en) | 1982-05-20 |
| JPH0115839B2 true JPH0115839B2 (en) | 1989-03-20 |
Family
ID=15640828
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55157038A Granted JPS5780591A (en) | 1980-11-10 | 1980-11-10 | Nuclear reactor control rod |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5780591A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6060585A (en) * | 1983-09-13 | 1985-04-08 | 株式会社日立製作所 | Control rod for nuclear reactor |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5780590A (en) * | 1980-11-10 | 1982-05-20 | Nippon Atomic Ind Group Co | Nuclear reactor control rod |
-
1980
- 1980-11-10 JP JP55157038A patent/JPS5780591A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5780590A (en) * | 1980-11-10 | 1982-05-20 | Nippon Atomic Ind Group Co | Nuclear reactor control rod |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5780591A (en) | 1982-05-20 |
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