JPS6330595B2 - - Google Patents
Info
- Publication number
- JPS6330595B2 JPS6330595B2 JP54027740A JP2774079A JPS6330595B2 JP S6330595 B2 JPS6330595 B2 JP S6330595B2 JP 54027740 A JP54027740 A JP 54027740A JP 2774079 A JP2774079 A JP 2774079A JP S6330595 B2 JPS6330595 B2 JP S6330595B2
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- fuel channel
- center
- bending moment
- spacer
- 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
- 239000000446 fuel Substances 0.000 claims description 61
- 125000006850 spacer group Chemical group 0.000 claims description 19
- 238000005452 bending Methods 0.000 description 17
- 238000010586 diagram Methods 0.000 description 5
- 238000009835 boiling Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000007423 decrease Effects 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】
〔産業上の利用分野〕
本発明は原子炉、特に沸騰水型原子炉の燃料集
合体に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel assembly for a nuclear reactor, particularly a boiling water reactor.
従来のこの種の燃料集合体は第１図に示すよう
に、断面が正方形状の燃料チヤンネル１と、この
燃料チヤンネル１内に多数挿入される燃料棒２
と、燃料棒２の上部側および下部側を支持する上
部タイプレート３および下部タイプレート４と、
上部タイプレート３と下部タイプレート４との間
に複数個（この場合７個）配置され、且つ前記燃
料棒２を支持するスペーサ格子５から成つてい
る。このスペーサ格子５は第２図に示す如く、燃
料チヤンネル１の長手方向に等間隔で配設されて
いる。なお、この種の燃料集合体が記載されてい
るものには実開昭52−110296号公報等がある。
As shown in FIG. 1, a conventional fuel assembly of this type includes a fuel channel 1 having a square cross section, and a large number of fuel rods 2 inserted into the fuel channel 1.
and an upper tie plate 3 and a lower tie plate 4 that support the upper and lower sides of the fuel rods 2,
A plurality of (seven in this case) spacer grids 5 are disposed between the upper tie plate 3 and the lower tie plate 4 and support the fuel rods 2. The spacer grids 5 are arranged at equal intervals in the longitudinal direction of the fuel channel 1, as shown in FIG. Incidentally, this type of fuel assembly is described in Japanese Utility Model Application Publication No. 52-110296, etc.
〔発明が解決しようとする問題点〕
上記のように構成されている燃料集合体におい
て、例えば地震等による異常状態が発生した場
合、燃料チヤンネル内の燃料棒２が大きく変形
し、燃料棒２からの荷重が集中的にスペーサ格子
５を介して燃料チヤンネル１の中心部（図示ｃ
点）に加わり、このために中心部附近の曲率が局
部的に大きくなつて燃料チヤンネルの中心部の強
度が低下する。また、中心部の狭い範囲内で塑性
変形を生じて燃料チヤンネル１が損傷する恐れが
ある。上記従来技術は、曲げモーメントが最大値
となる中心部付近の強度上の問題については配慮
されていなかつた。[Problems to be Solved by the Invention] In the fuel assembly configured as described above, when an abnormal condition occurs, for example due to an earthquake, the fuel rods 2 in the fuel channel are greatly deformed, and the fuel rods 2 The load is concentrated through the spacer grid 5 in the center of the fuel channel 1 (shown c
This causes the curvature near the center to locally increase, reducing the strength at the center of the fuel channel. Furthermore, there is a risk that plastic deformation may occur within a narrow area at the center, resulting in damage to the fuel channel 1. The above-mentioned conventional technology does not take into account strength problems near the center where the bending moment reaches its maximum value.
本発明は燃料チヤンネルの中心部に加わる大き
な集中荷重を低減させることを目的としている。 The present invention aims to reduce the large concentrated loads applied to the center of the fuel channel.
上記目的は、断面が正方形状の燃料チヤンネル
内に挿入される多数の燃料棒と、この燃料棒を支
持する複数個のスペーサ格子から成る燃料集合体
において、前記スペーサ格子を前記燃料棒の長手
方向中心の両側に配置し、その配置間隔を前記燃
料棒の上部側及び下部側よりも中心部の方を大き
くすることによつて達成される。
The above object is to provide a fuel assembly consisting of a large number of fuel rods inserted into a fuel channel having a square cross section and a plurality of spacer lattices supporting the fuel rods. This is achieved by arranging the fuel rods on both sides of the center and making the spacing between the fuel rods larger at the center than at the upper and lower sides of the fuel rods.
燃料チヤンネルの強度は燃料チヤンネルのどこ
か一箇所でもある閾値に達すると破損が生じてし
まうが、上記した構成により平均的に荷重を支え
ることができるため、燃料チヤンネルの中心部に
加わる大きな集中荷重を低減させることができ
る。
If the strength of the fuel channel reaches a threshold value at any one point in the fuel channel, damage will occur, but because the above structure can support the load evenly, it is possible to avoid large concentrated loads applied to the center of the fuel channel. can be reduced.
以下本発明の実施例を図面により説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第３図において、第１図と同符号のものは同一
部分を示す。 In FIG. 3, the same reference numerals as in FIG. 1 indicate the same parts.
６は前記燃料棒２を支持する複数個（この場合
６個）のスペーサ格子で、このスペーサ格子６は
前記燃料チヤンネル１の長手方向の中心部（図示
ｃ点）を避けて配慮されている。 Reference numeral 6 denotes a plurality of (six in this case) spacer lattices that support the fuel rods 2, and the spacer lattices 6 are designed to avoid the longitudinal center of the fuel channel 1 (point c in the figure).
次に上記のように燃料集合体を構成することに
より、従来のように燃料チヤンネル１の長手方向
に加わる集中荷重が低減されることを第４図イ，
ロにより説明する。第４図イ，ロは有限要素法に
より求めた計算結果を示したものである。第４図
イにおいて、曲線ａは燃料棒、スペーサ格子を除
いた燃料チヤンネル単体の両端側に曲げ力を加え
たときの曲げモーメント曲率曲線を示すもので、
横軸には燃料チヤンネルの曲率が縦軸には曲げモ
ーメントがそれぞれ採つている。また、第４図ロ
は前記曲げモーメント曲率曲線ａをもとにして得
られた燃料棒、スペーサ格子を含む曲げモーメン
ト分布曲線と曲率分布曲線を示したもので、横軸
には燃料チヤンネルの中心部からの距離を、縦軸
には曲げモーメントが採つてあり、実線で示す曲
線ｂ，ｄは本発明のスペーサ格子の配置における
曲げモーメント分布曲線、曲率分布曲線を、破線
で示す曲線b′，d′は従来のスペーサ格子配置にお
ける曲げモーメント分布曲線、曲率分布曲線をそ
れぞれ示している。この第４図ロから明らかなよ
うに、従来のスペーサ格子の位置、いわゆる燃料
チヤンネルの中心部にスペーサ格子が配設されて
いる場合、曲げモーメント分布曲線b′、曲率分布
曲線d′ともに燃料チヤンネルの中心部で局部的に
大きくなつているため、前述したようにこの中心
部で燃料チヤンネルの強度が低下する。 Next, by configuring the fuel assembly as described above, the concentrated load applied in the longitudinal direction of the fuel channel 1 as in the conventional case is reduced.
This will be explained by b. Figures 4A and 4B show the calculation results obtained using the finite element method. In Figure 4A, curve a shows the bending moment curvature curve when bending force is applied to both ends of the fuel channel alone, excluding the fuel rods and spacer grid.
The horizontal axis shows the curvature of the fuel channel, and the vertical axis shows the bending moment. In addition, Fig. 4B shows the bending moment distribution curve and curvature distribution curve including the fuel rods and spacer grids obtained based on the bending moment curvature curve a, and the horizontal axis shows the center of the fuel channel. The vertical axis shows the bending moment, and the curves b and d shown by solid lines are bending moment distribution curves in the arrangement of the spacer grid of the present invention, and the curves b' and d, shown by broken lines, are the curvature distribution curves. d′ shows the bending moment distribution curve and curvature distribution curve, respectively, in the conventional spacer grid arrangement. As is clear from Fig. 4B, when the conventional spacer grid is arranged at the position of the spacer grid, that is, at the center of the fuel channel, both the bending moment distribution curve b' and the curvature distribution curve d' Because the fuel channel becomes locally large in the center, the strength of the fuel channel decreases in this center, as described above.
これに対して本発明のスペーサ格子位置、いわ
ゆる燃料チヤンネルの中心部の両側に上部側及び
下部側よりも間隔を大きくしてスペーサ格子が配
置されている場合、中心部の曲げモーメント分布
曲線ｂ、曲率分布曲線ｄともに従来のそれよりも
小さくなつている。燃料チヤンネルの強度は燃料
チヤンネルのどこか一箇所でもある閾値に達する
と破損が生じて使用が不可能となるが、本発明
は、同じ地震荷重を受けた場合、曲げモーメント
分布などが従来よりも大きくなつても最大値が従
来のものよりも小さくすることができるため燃料
チヤンネルの強度は同上する。 On the other hand, in the case where the spacer grid of the present invention is arranged on both sides of the center of the fuel channel with a larger interval than on the upper and lower sides, the bending moment distribution curve b at the center, Both curvature distribution curves d are smaller than the conventional ones. If the strength of the fuel channel reaches a threshold value at any point in the fuel channel, damage will occur and the fuel channel will become unusable. However, with the present invention, when subjected to the same seismic load, the bending moment distribution etc. will be lower than before. Even if the fuel channel becomes larger, the maximum value can be made smaller than that of the conventional one, so the strength of the fuel channel is the same as above.
また、発生する応力は曲げモーメントに比例す
ることから、曲げモーメント分布が一様であれば
燃料チヤンネルは荷重を均等に分担していること
になるため、曲げモーメントの最大値を下げるこ
とは燃料チヤンネルの強度向上につながる。 In addition, since the stress generated is proportional to the bending moment, if the bending moment distribution is uniform, the fuel channel will be sharing the load equally, so reducing the maximum bending moment will This leads to improved strength.
本発明によれば、燃料チヤンネルの中心部付近
に加わる大きな集中荷重を低減させることがで
き、また燃料チヤンネルの中心部の狭い範囲内で
の塑性変形を防ぐことができる。
According to the present invention, a large concentrated load applied to the vicinity of the center of the fuel channel can be reduced, and plastic deformation within a narrow range of the center of the fuel channel can be prevented.
第１図は沸騰水型原子炉の燃料集合体の構成を
示す概略図、第２図は従来の燃料集合体における
スペーサ格子の配置を示す図、第３図は本発明の
燃料集合体におけるスペーサ格子の配置を示す
図、第４図イ，ロは有限要素法により求めた燃料
チヤンネルの曲げモーメント曲率曲線、曲げモー
メント分布曲線および曲率分布曲線を示す図であ
る。
１…燃料チヤンネル、２…燃料棒、６…スペー
サ格子。
Fig. 1 is a schematic diagram showing the configuration of a fuel assembly for a boiling water reactor, Fig. 2 is a diagram showing the arrangement of spacer grids in a conventional fuel assembly, and Fig. 3 is a diagram showing the arrangement of spacer grids in a fuel assembly of the present invention. FIGS. 4A and 4B, which are diagrams showing the arrangement of the grids, are diagrams showing the bending moment curvature curve, bending moment distribution curve, and curvature distribution curve of the fuel channel obtained by the finite element method. 1...Fuel channel, 2...Fuel rod, 6...Spacer grid.
Claims (1)
れる多数の燃料棒と、この燃料棒を支持する複数
個のスペーサ格子から成る燃料集合体において、
前記スペーサ格子を前記燃料棒の長手方向中心の
両側に配置し、その配置間隔は前記燃料棒の上部
側及び下部側よりも中心部の方を大きくしたこと
を特徴とする燃料集合体。1. In a fuel assembly consisting of a large number of fuel rods inserted into a fuel channel having a square cross section and a plurality of spacer grids that support the fuel rods,
A fuel assembly characterized in that the spacer grids are arranged on both sides of the longitudinal center of the fuel rods, and the spacing between the spacer grids is larger at the center than at the upper and lower sides of the fuel rods.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2774079A JPS55121192A (en) | 1979-03-12 | 1979-03-12 | Fuel assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2774079A JPS55121192A (en) | 1979-03-12 | 1979-03-12 | Fuel assembly |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55121192A JPS55121192A (en) | 1980-09-18 |
| JPS6330595B2 true JPS6330595B2 (en) | 1988-06-20 |
Family
ID=12229421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2774079A Granted JPS55121192A (en) | 1979-03-12 | 1979-03-12 | Fuel assembly |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55121192A (en) |
-
1979
- 1979-03-12 JP JP2774079A patent/JPS55121192A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55121192A (en) | 1980-09-18 |
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