JPS6318152B2 - - Google Patents
Info
- Publication number
- JPS6318152B2 JPS6318152B2 JP54051452A JP5145279A JPS6318152B2 JP S6318152 B2 JPS6318152 B2 JP S6318152B2 JP 54051452 A JP54051452 A JP 54051452A JP 5145279 A JP5145279 A JP 5145279A JP S6318152 B2 JPS6318152 B2 JP S6318152B2
- Authority
- JP
- Japan
- Prior art keywords
- control rod
- structural member
- central structural
- fuel
- 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
Links
- 238000010521 absorption reaction Methods 0.000 claims description 16
- 239000000126 substance Substances 0.000 claims description 5
- 239000000446 fuel Substances 0.000 description 30
- 239000000463 material Substances 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 230000000712 assembly Effects 0.000 description 4
- 238000000429 assembly Methods 0.000 description 4
- 239000002826 coolant Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000009835 boiling Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- 238000013459 approach Methods 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
- 238000010586 diagram Methods 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel 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
Landscapes
- Monitoring And Testing Of Nuclear Reactors (AREA)
Description
【発明の詳細な説明】
本発明は原子炉の制御棒に関し、特に制御棒引
き抜きの際に周辺の燃料棒に生ずる出力の急激な
変化を緩和する制御棒に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control rod for a nuclear reactor, and more particularly to a control rod that alleviates sudden changes in output that occur in surrounding fuel rods when the control rod is withdrawn.
原子炉の制御棒は原子炉炉心の反応度および出
力分布を制御するために使用される装置であり、
内部にボロン、ユーロピウム、ハフニウムなどの
中性子吸収断面積の大きい物質（以下中性子吸収
物質と呼ぶ）が含まれている。 A nuclear reactor control rod is a device used to control the reactivity and power distribution of a nuclear reactor core.
It contains substances with large neutron absorption cross sections (hereinafter referred to as neutron absorption substances) such as boron, europium, and hafnium.
第１図は従来の沸騰水型原子炉（以下BWRと
呼ぶ）に使用される十字型制御棒を示す図であ
る。制御棒１は４枚のブレード２を中央構造材３
で結合した十字型の構造である。ブレード２はシ
ース４から成り、シース４内にはステンレス鋼製
管５（以下吸収棒と呼ぶ）が並んで挿入されてい
る。吸収棒５の内部には吸収断面積の大きな物
質、通常はボロンカーバイド（B4C）の粉末が封
入されている。 FIG. 1 is a diagram showing a cross-shaped control rod used in a conventional boiling water reactor (hereinafter referred to as BWR). The control rod 1 has four blades 2 connected to the central structural member 3.
It has a cross-shaped structure connected by . The blade 2 consists of a sheath 4, into which stainless steel tubes 5 (hereinafter referred to as absorption rods) are inserted side by side. A substance with a large absorption cross section, usually boron carbide (B 4 C) powder, is sealed inside the absorption rod 5 .
そして、この制御棒１の上部には制御棒１を上
方から支持する時に用いられる取手６と、図示し
ない炉心内に制御棒１を挿入する時に炉心下部と
の当りを防止するボール７とが設けられている。
また、前記シース４内の吸収棒５を冷却するため
に、シース４に冷却材侵入口８が穿設されてお
り、この冷却材侵入口８を介して冷却材がシース
４内を流通して前記吸収棒５を冷却するように成
つている。 At the top of the control rod 1, there are provided a handle 6 used to support the control rod 1 from above and a ball 7 (not shown) that prevents the control rod 1 from hitting the lower part of the core when inserted into the core. It is being
Further, in order to cool the absorption rod 5 inside the sheath 4, a coolant inlet 8 is provided in the sheath 4, and the coolant flows through the sheath 4 through the coolant inlet 8. It is configured to cool the absorption rod 5.
第２図は沸騰水型原子炉（BWR）の十字型制
御棒の燃料集合体の原子炉炉心内での配置を示し
た断面図である。BWRの燃料集合体は通常７行
７列もしくは８行８列の正方格子状に燃料棒１０
を束ねており、チヤンネルボツクス９で取り囲ん
でいる。十字型制御棒は４個の燃料集合体の間の
ギヤツプ１１に第２図のごとく挿入されている。
BWRの炉心は第２図の配置を単位として構成さ
れている。制御棒４が挿入されていない場合に
は、燃料集合体内での燃料棒ごとの水平方向出力
分布（一般に局所出力分布と呼ばれている）はほ
ぼ平坦になるように燃料棒ごとの核分裂性物質の
濃度を分布させている。燃料集合体に隣接する制
御棒が挿入されずに出力運転する場合には、核分
裂性物質の燃焼につれて局所出力分布は通常さら
に平坦になる。 FIG. 2 is a cross-sectional view showing the arrangement of fuel assemblies for cross-shaped control rods in a boiling water reactor (BWR) within the reactor core. BWR fuel assemblies usually have 10 fuel rods arranged in a square grid of 7 rows and 7 columns or 8 rows and 8 columns.
are tied together and surrounded by channel boxes 9. The cruciform control rod is inserted into the gap 11 between the four fuel assemblies as shown in FIG.
The BWR core is constructed using the arrangement shown in Figure 2 as a unit. When no control rod 4 is inserted, the horizontal power distribution for each fuel rod within the fuel assembly (generally referred to as the local power distribution) is approximately flat, so that the fissile material for each fuel rod is approximately flat. The concentration of is distributed. When operating at power with no control rods adjacent to the fuel assembly inserted, the local power distribution typically becomes flatter as the fissile material burns.
また、BWRでは通常定格出力運転時でも全数
の１〜２割の制御棒が挿入されている。挿入され
た制御棒に隣接する燃料集合体では、制御棒に近
い燃料棒ほど出力が小さく、局所出力分布は大き
く歪んでいる。このため制御棒に隣接する燃料集
合体では制御棒から離れた燃料棒内の核分裂性物
質は、制御棒に近い燃料棒の核分裂性物質より多
く消費される。隣接する制御棒が挿入された状態
で出力運転された後に制御棒を引き抜いた場合の
燃料集合体の局所出力は、核分裂性物質の残存割
合の大きい制御棒に近い燃料棒で大きくなる。特
に十字型制御棒に最も近いコーナー付近の燃料棒
で局所出力の増大する割合が大きい。 In addition, in a BWR, 10 to 20% of the control rods are inserted even during normal rated output operation. In the fuel assembly adjacent to the inserted control rod, the closer the fuel rod is to the control rod, the smaller the output, and the local output distribution is greatly distorted. Therefore, in a fuel assembly adjacent to a control rod, the fissile material in the fuel rods remote from the control rod is consumed more than the fissile material in the fuel rods closer to the control rod. When a control rod is pulled out after power operation with an adjacent control rod inserted, the local power of the fuel assembly becomes larger in the fuel rods near the control rod, which have a larger proportion of remaining fissile material. In particular, the local power increases at a large rate in the fuel rods near the corners closest to the cruciform control rods.
BWRでは核分裂性物質が燃焼するにつれて、
炉心の臨界を保つために制御棒を引き抜いてゆく
ことが必要となる。また燃料を平均的に消費する
ため、一定期間運転した後に挿入している制御棒
の位置を変更（制御棒パターンの変更）を行な
う。 In a BWR, as fissile material burns,
It is necessary to withdraw the control rods to maintain the criticality of the reactor core. In order to consume fuel evenly, the position of the inserted control rods is changed (change of control rod pattern) after a certain period of operation.
制御棒の引き抜き操作を出力運転状態で行なう
と、隣接する燃料集合体の出力は大幅に変化す
る。制御棒に最も近いコーナー付近の燃料棒は水
平方向の局所出力分布が前記のごとく変化するた
め特に大きく変化する。これは燃料の健全性維持
の上で好ましくない。 If a control rod withdrawal operation is performed during power operation, the power of adjacent fuel assemblies will change significantly. The fuel rods near the corners closest to the control rods change particularly greatly because the local power distribution in the horizontal direction changes as described above. This is unfavorable in terms of maintaining the integrity of the fuel.
本発明は上述の事情を考慮してなされたもの
で、制御棒引き抜きの際に生ずる、燃料集合体で
制御棒に最も近いコーナー付近の燃料棒の急激な
出力変化を緩和する原子炉の制御棒を提供するこ
とにある。 The present invention has been made in consideration of the above-mentioned circumstances, and is a control rod for a nuclear reactor that alleviates sudden changes in the output of the fuel rods near the corner of the fuel assembly closest to the control rods that occurs when the control rods are withdrawn. Our goal is to provide the following.
本発明によれば制御棒の中央構造材に減速材領
域を設けたことを特徴とする原子炉の制御棒が得
られる。 According to the present invention, a control rod for a nuclear reactor is obtained, which is characterized in that a moderator region is provided in the central structural member of the control rod.
以下本発明の実施例について第３図および第４
図を参照して詳細に説明する。第３図は十字型制
御棒について本発明を実施した第１の実施例を示
す。第３図において、中央構造材３にはシース４
が取り付けられており、シース内部には吸収棒５
が挿入されている。そして、この吸収棒５内には
中性子吸収物質（例えばB4C）１３が充填されて
いる。また、前記中央構造材３には内部の軸方向
に減速材（水）の流通する流通孔１４が形成され
ている。そして、この流通孔１４は内部に減速材
を流通させるために軸方向の上・下部の所定位置
に開口部（図示せず）が形成されている。 Embodiments of the present invention will be described below with reference to FIGS. 3 and 4.
This will be explained in detail with reference to the drawings. FIG. 3 shows a first embodiment of the present invention for a cross-shaped control rod. In FIG. 3, a sheath 4 is attached to the central structural member 3.
is attached, and an absorption rod 5 is installed inside the sheath.
is inserted. The absorption rod 5 is filled with a neutron absorption substance (for example, B 4 C) 13 . Further, the central structural member 3 is formed with a communication hole 14 through which a moderator (water) flows in the internal axial direction. The communication hole 14 has openings (not shown) formed at predetermined upper and lower positions in the axial direction to allow the moderator to flow therein.
以上の構成によれば、従来の十字型制御棒より
中央構造材の内部に形成された流通孔により減速
材である水の占める領域が拡大されるために中性
子の減速効果が向上すること、及び中央構造材の
量が流通孔によつて減少することにともなつて中
性子吸収量が減少することによつて中央構造材付
近での熱中性子束が大きくなるため、燃料集合体
の局所出力分布の歪みを緩和することができる。
特に制御棒に最も近いコーナー付近の燃料棒の局
所出力が制御棒挿入時に低下する割合を小さくす
ることができる。制御棒挿入時の局所出力分布が
平坦化されることによつて核分裂性物質の残存す
る割合も平坦な分布に近くなり、制御棒引き抜き
後の局所出力分布も平坦化される。 According to the above configuration, the area occupied by water, which is a moderator, is expanded by the flow holes formed inside the central structural member compared to the conventional cross-shaped control rod, so that the neutron moderating effect is improved; As the amount of central structural material is reduced by the flow holes, the amount of neutron absorption decreases, and the thermal neutron flux near the central structural material increases, resulting in a change in the local power distribution of the fuel assembly. Distortion can be alleviated.
In particular, the rate at which the local power of the fuel rod near the corner closest to the control rod decreases when the control rod is inserted can be reduced. By flattening the local power distribution when the control rod is inserted, the proportion of remaining fissile material approaches a flat distribution, and the local power distribution after the control rod is withdrawn is also flattened.
次に本発明の他の実施例を第４図ａ〜ｃを参照
して説明する。なお、第４図において、第３図と
同一部分には同一符号を付して、その部分の構成
の説明は省略する。第４図ａ及び第４図ｂは中央
構造材をシース１５にて構成し、内部に減速材の
流通領域１６を形成している。そして、この流通
領域１６は内部に減速材を流通させるために軸方
向の上・下部の所定位置に開口部（図示せず）が
形成されている。 Next, another embodiment of the present invention will be described with reference to FIGS. 4a to 4c. In FIG. 4, the same parts as in FIG. 3 are given the same reference numerals, and the explanation of the structure of the parts will be omitted. In FIGS. 4a and 4b, the central structural member is constituted by a sheath 15, and a moderator flow region 16 is formed inside. This flow region 16 has openings (not shown) formed at predetermined positions in the upper and lower parts of the axial direction to allow the moderator to flow therein.
以上の構成によつて、本発明の第１実施例と同
様の効果を得ることができ、さらには減速材の流
通領域をより大きく広げることができるので燃料
集合体のコーナー付近の燃料棒の出力変化を第１
実施例より減少させることができる。 With the above configuration, it is possible to obtain the same effects as in the first embodiment of the present invention, and furthermore, the flow area of the moderator can be further expanded, so that the output of the fuel rods near the corners of the fuel assembly can be increased. Change first
It can be reduced from the example.
また、第４図ｃに示すように、中央構造材をシ
ース１７にて形成し、このシース１７の結合部を
補強ビーム１８にて補強させ、この補強ビーム１
８とシース１７とによつて形成される減速材の流
通領域１９に内部を減速材が流通する中空管２０
を配置させる構成にすれば、本発明の第１実施例
と同様の効果の他にさらに制御棒を強固なものに
することができる。 Furthermore, as shown in FIG.
8 and the sheath 17, a hollow tube 20 through which the moderator flows through a moderator flow region 19;
By arranging the control rod, the control rod can be further strengthened in addition to the same effect as the first embodiment of the present invention.
以上説明した様に本発明に係る制御棒によれ
ば、中央構造材付近の中性子吸収量が少なく、減
速材として水の領域が大きくなるため、燃料集合
体の局所出力分布の歪みを緩和させることができ
る。 As explained above, according to the control rod according to the present invention, the amount of neutron absorption near the central structural member is small and the area of water acting as a moderator becomes large, so that the distortion in the local power distribution of the fuel assembly can be alleviated. Can be done.
第１図は従来の制御棒を示す外観図、第２図は
制御棒と燃料集合体の関係を示す横断面図、第３
図は本発明の第１の実施例を示す制御棒の横断面
図、第４図ａ〜ｂはそれぞれ本発明の他の実施例
を示す制御棒の横断面図である。
１……十字型制御棒、３……中央構造材、４…
…シース、５……吸収棒、１３……中性子吸収物
質、１４……流通孔、１５，１７……シース、１
６，１９……流通領域、１８……補強ビーム、２
０……中空管。
Figure 1 is an external view showing a conventional control rod, Figure 2 is a cross-sectional view showing the relationship between the control rod and the fuel assembly, and Figure 3 is a cross-sectional view showing the relationship between the control rod and the fuel assembly.
The figure is a cross-sectional view of a control rod showing a first embodiment of the present invention, and FIGS. 4a to 4b are cross-sectional views of control rods showing other embodiments of the present invention. 1...Cross-shaped control rod, 3...Central structural member, 4...
... Sheath, 5 ... Absorption rod, 13 ... Neutron absorption material, 14 ... Distribution hole, 15, 17 ... Sheath, 1
6, 19... Distribution area, 18... Reinforcement beam, 2
0...Hollow tube.
Claims (1)
棒と、前記吸収棒を内部に並列に配置するシース
および複数のシースを結合する中央構造材とから
なる制御棒において、前記中央構造材の軸方向内
部に減速材の流通する領域を設けて成ることを特
徴とする制御棒。 ２ 前記減速材の流通する領域は、中央構造材の
軸方向の中心部に形成された孔から成ることを特
徴とする特許請求の範囲第１項記載の制御棒。 ３ 前記減速材の流通する領域は、中空な中央構
造材と、この中央構造材内に配置され内部を減速
材が流通する中空管とから形成されて成ることを
特徴とする特許請求の範囲第１項記載の制御棒。[Claims] 1. A control rod comprising a plurality of absorption rods filled with a neutron absorbing substance, a sheath in which the absorption rods are arranged in parallel, and a central structural member connecting the plurality of sheaths, A control rod characterized in that a region through which a moderator flows is provided inside the central structural member in the axial direction. 2. The control rod according to claim 1, wherein the region through which the moderator flows is comprised of a hole formed in the axial center of the central structural member. 3. Claims characterized in that the region through which the moderator flows is formed of a hollow central structural member and a hollow tube disposed within the central structural member through which the moderator flows. The control rod according to item 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5145279A JPS55143490A (en) | 1979-04-27 | 1979-04-27 | Control rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5145279A JPS55143490A (en) | 1979-04-27 | 1979-04-27 | Control rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55143490A JPS55143490A (en) | 1980-11-08 |
| JPS6318152B2 true JPS6318152B2 (en) | 1988-04-16 |
Family
ID=12887316
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5145279A Granted JPS55143490A (en) | 1979-04-27 | 1979-04-27 | Control rod |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55143490A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0271565U (en) * | 1988-11-16 | 1990-05-31 | ||
| JPH0343861U (en) * | 1989-09-08 | 1991-04-24 |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS592469U (en) * | 1982-06-30 | 1984-01-09 | 昭和電線電纜株式会社 | Hot air circulation type enameled wire baking furnace |
| JPS6026731U (en) * | 1983-07-29 | 1985-02-23 | 東京特殊電線株式会社 | Enamelled wire manufacturing equipment |
| JPS6082885A (en) * | 1983-10-12 | 1985-05-11 | 株式会社東芝 | Control rod for nuclear reactor |
| JP2009058447A (en) * | 2007-08-31 | 2009-03-19 | Toshiba Corp | Control rod for reactor |
-
1979
- 1979-04-27 JP JP5145279A patent/JPS55143490A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0271565U (en) * | 1988-11-16 | 1990-05-31 | ||
| JPH0343861U (en) * | 1989-09-08 | 1991-04-24 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55143490A (en) | 1980-11-08 |
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