JP2807960B2 - Foreign substance countermeasure type PWR fuel assembly - Google Patents
Foreign substance countermeasure type PWR fuel assemblyInfo
- Publication number
- JP2807960B2 JP2807960B2 JP5314545A JP31454593A JP2807960B2 JP 2807960 B2 JP2807960 B2 JP 2807960B2 JP 5314545 A JP5314545 A JP 5314545A JP 31454593 A JP31454593 A JP 31454593A JP 2807960 B2 JP2807960 B2 JP 2807960B2
- Authority
- JP
- Japan
- Prior art keywords
- fuel assembly
- water
- lower nozzle
- foreign matter
- support grid
- 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
Landscapes
- Monitoring And Testing Of Nuclear Reactors (AREA)
- Nozzles (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は、加圧水型原子炉(PW
R)にて使用される燃料集合体に係り、詳しくは、下部
ノズルの流水孔を通って流出する冷却水中の異物を捕捉
する異物対策型PWR燃料集合体に関するものである。The present invention relates to a pressurized water reactor (PW).
More specifically, the present invention relates to a foreign matter countermeasure type PWR fuel assembly that captures foreign matter in cooling water flowing out through a water hole of a lower nozzle.
【0002】[0002]
【従来の技術】加圧水型原子炉にて使用される燃料集合
体は、多数の燃料棒を並列し、かつシンブル管等を混入
して複数の支持格子で支持せしめた燃料棒束部と、それ
を固定する上部ノズルと下部ノズルとで構成されてい
る。そして、上記下部ノズル6′は、図6に示す如く、
燃料集合体の骨格となる上記シンブル管を固定する複数
のシンブルスクリュー穴Sと多数の流水孔7′とを有す
る四角形のアダプタプレート8′と、該アダプタプレー
ト8′のコーナー部から垂下し、下部炉心板Bとの間に
所定の間隔を設けて上記アダプタプレート8′を支持せ
しめる4本の脚部とによって構成されている。2. Description of the Related Art A fuel assembly used in a pressurized water nuclear reactor is composed of a fuel rod bundle in which a number of fuel rods are arranged in parallel and supported by a plurality of support grids by mixing thimble tubes and the like. Is constituted by an upper nozzle and a lower nozzle. Then, the lower nozzle 6 'is, as shown in FIG.
A rectangular adapter plate 8 'having a plurality of thimble screw holes S for fixing the thimble tube serving as a skeleton of the fuel assembly and a large number of water holes 7'; And four legs for supporting the adapter plate 8 'at a predetermined distance from the core plate B.
【0003】一方、上記加圧水型原子炉においては、冷
却水は図5に示す如き下部炉心板Bに設けられた炉心板
流水孔Hより燃料集合体の下部ノズル6′に至り、この
下部ノズル6′に至った冷却水は、図6に示すような下
部ノズル6′にあけられた前記多数の流水孔7′より燃
料集合体内へ流入し、支持格子・燃料棒の間を通って上
部ノズルに至る。そして、上部ノズルの流水孔を通過し
た冷却水は蒸気発生器等を経て下部炉心板Bへ至り循環
する。On the other hand, in the above pressurized water reactor, cooling water flows from a core plate flow hole H provided in a lower core plate B to a lower nozzle 6 'of a fuel assembly as shown in FIG. ′ Flows into the fuel assembly through the large number of water holes 7 ′ opened in the lower nozzle 6 ′ as shown in FIG. 6 and passes through the space between the support grid and the fuel rod to the upper nozzle. Reach. Then, the cooling water that has passed through the flow holes of the upper nozzle reaches the lower core plate B via a steam generator or the like and circulates.
【0004】ところで、この冷却水の系統にまぎれ込ん
だ金属片等の異物は、下部ノズルの流水孔を通過したの
ちは、燃料集合体の燃料棒の間に引掛かることが多く、
この引掛かった異物は、冷却水流によって激しく振動
し、燃料棒を傷つけることがある。そこで、従来におい
ては、この異物の燃料体内への流入を防ぐために、例え
ば図4に示すように、上記下部ノズルのアダプタプレー
ト8′上に最下部の支持格子3′を近接させ、この支持
格子3′の格子板9′によって前記流水孔7′の出口を
十文字状に細分化している。[0004] By the way, foreign matters such as metal pieces mixed into the cooling water system are often caught between fuel rods of the fuel assembly after passing through the flow hole of the lower nozzle.
The trapped foreign matter vibrates violently by the cooling water flow, and may damage the fuel rod. Therefore, conventionally, in order to prevent the foreign matter from flowing into the fuel body, as shown in FIG. 4, for example, the lowermost support grid 3 'is brought close to the adapter plate 8' of the lower nozzle, The outlet of the water hole 7 'is subdivided into a cross shape by a 3' lattice plate 9 '.
【0005】[0005]
【発明が解決しようとする課題】しかしながら、上記の
如き異物対策を図った燃料集合体においても、上記細分
化された流路より小さい異物は上記下部ノズルを通り抜
けることが可能である。即ち、この小さな流路を抜ける
立方体または球状に近いような短尺の異物は、上方の他
の支持格子も通過するために前記損傷の原因とはなりに
くいが、特にワイヤ片等の長尺棒状の異物Tは、図4に
示すように、縦の状態では上記細分化経路を通り抜ける
ことができ、一方、横の状態となった場合は上方の他の
支持格子に引掛かり、前記燃料棒の損傷の原因となる可
能性がある。However, even in the fuel assembly in which the above foreign matter countermeasures are taken, foreign matter smaller than the above-mentioned subdivided flow path can pass through the lower nozzle. That is, a short foreign substance such as a cubic or spherical shape that passes through this small flow path does not easily cause the damage because it also passes through the other supporting grids above. As shown in FIG. 4, the foreign matter T can pass through the above-described subdivision path in the vertical state, while it is caught by another support lattice above when the state is horizontal, and the fuel rod is damaged. May cause
【0006】本発明は上記の如き実状に鑑み、下部ノズ
ルの流水孔に新規な構成を見出すことによって、上記ワ
イヤ片等の長尺棒状の異物をも上記下部ノズルで捕捉せ
しめることを目的とするものである。The present invention has been made in view of the above situation, and has as its object to find a long rod-shaped foreign matter such as the above-mentioned wire piece by the above-mentioned lower nozzle by finding a new structure in the water hole of the lower nozzle. Things.
【0007】[0007]
【課題を解決するための手段】即ち、上記目的に適合す
る本発明のPWR燃料集合体は、前述の如き多数の流水
孔を有する下部ノズルのアダプタプレート上に、最下部
の支持格子を近接させ、該支持格子の格子板にて上記流
水孔出口を細分化してなる燃料集合体において、上記流
水孔の穿向角度を、上記支持格子の流路方向に対して傾
斜せしめたことを特徴とする。That is, a PWR fuel assembly according to the present invention that meets the above-mentioned object has a lowermost support grid placed close to an adapter plate of a lower nozzle having a large number of water holes as described above. In a fuel assembly obtained by subdividing the outlet of the water holes with a grid plate of the support grid, the perforation angle of the water holes is inclined with respect to the flow direction of the support grid. .
【0008】上記流水孔の穿向角度としては、捕捉する
異物が長い程小さい傾斜で済むが、実際上は上記略垂直
に形成される流路に対し、概ね20〜40度の範囲で傾
斜することが好適である。[0008] The perforation angle of the water hole is small as the foreign matter to be captured is longer. However, in actuality, the water hole is inclined at an angle of about 20 to 40 degrees with respect to the substantially vertical flow path. Is preferred.
【0009】[0009]
【作用】上記本発明の燃料集合体では、流水孔と支持格
子とが形成する経路がくの字状に屈曲することから、こ
の屈曲した経路により前述の如き長尺棒状の異物を詰ま
らせて、これを捕捉することが可能となる。In the fuel assembly according to the present invention, since the path formed by the water holes and the support grid is bent in a V-shape, the bent path blocks the long rod-shaped foreign matter as described above, This can be captured.
【0010】[0010]
【実施例】以下、さらに添付図面を参照して、本発明の
実施例を説明する。Embodiments of the present invention will be described below with reference to the accompanying drawings.
【0011】図1は本発明実施例燃料集合体の下部ノズ
ル・アダプタプレートを示す部分拡大断面図、図2は同
実施例燃料集合体の概要図、図3は、同、燃料集合体の
下部ノズルと最下部支持格子を示す説明図である。FIG. 1 is a partially enlarged sectional view showing a lower nozzle adapter plate of a fuel assembly according to an embodiment of the present invention, FIG. 2 is a schematic view of the fuel assembly according to the embodiment, and FIG. It is explanatory drawing which shows a nozzle and a lowermost support grid.
【0012】上記本発明実施例の燃料集合体は、図2に
示すように、多数の燃料棒1を並列すると共に、これに
シンブル管2等を混入して、複数の支持格子3で支持せ
しめた燃料棒束部4と、この燃料棒束部4を固定する上
部ノズル5及び下部ノズル6とを具備する構成を有して
いる。そして、図3にも示すように、上記燃料集合体で
は、多数の流水孔7を有する下部ノズル6のアダプタプ
レート8上に、最下部の支持格子3′を近接させて、こ
の支持格子3′の格子板9にて上記流水孔7の出口を十
文字状に細分化している。In the fuel assembly according to the embodiment of the present invention, as shown in FIG. 2, a large number of fuel rods 1 are arranged in parallel, and thimble tubes 2 and the like are mixed in the fuel rods 1 and supported by a plurality of support grids 3. A fuel rod bundle 4 and an upper nozzle 5 and a lower nozzle 6 for fixing the fuel rod bundle 4. As shown in FIG. 3, in the fuel assembly, the lowermost support grid 3 'is brought close to the adapter plate 8 of the lower nozzle 6 having a large number of water holes 7 so that the support grid 3' The outlet of the water flow hole 7 is subdivided into a cross shape by the lattice plate 9.
【0013】一方、本発明実施例では、上記の如き燃料
集合体において、図1に示すように上記流水孔7の穿向
角度7aを、全て上記格子板9が形成する流路10の方
向10aに対し約30度の角度で傾斜するよう上記流水
孔7を形成せしめている。この流路の方向10aに対す
る流水孔7の穿向角度は、捕捉しようとする異物の長さ
や上記アダプタプレート8の厚さによっても異なってく
るが、上記略垂直に形成される流路10の流路方向10
aに対し、概ね20〜40度の範囲で傾斜することが、
後述する長尺棒状の異物を捕捉する上で好適である。On the other hand, in the embodiment of the present invention, in the fuel assembly as described above, as shown in FIG. 1, the perforation angle 7a of the water flow hole 7 is entirely changed in the direction 10a of the flow path 10 formed by the grid plate 9. The flowing water hole 7 is formed so as to be inclined at an angle of about 30 degrees with respect to. The perforation angle of the water flow hole 7 with respect to the direction 10a of the flow path depends on the length of the foreign matter to be captured and the thickness of the adapter plate 8, but the flow rate of the flow path 10 formed substantially vertically is different. Road direction 10
With respect to a, that it is inclined in a range of about 20 to 40 degrees,
It is suitable for catching a long rod-shaped foreign matter described later.
【0014】また、アダプタプレート8の一部には、上
記流水孔7以外に小径のものが形成されることもある
が、この小径流水孔(図示せず)の上方には前記格子板
9が必ずしも位置しないため、小径流水孔は、上記流水
孔7のように傾斜して形成しない場合もある。The adapter plate 8 may have a small diameter in addition to the water holes 7 in some cases. The grid plate 9 is provided above the small water holes (not shown). Since they are not necessarily located, the small-diameter water holes may not be formed as inclined as the water holes 7 described above.
【0015】しかして、上記構成を有する本発明実施例
の燃料集合体においては、図1に示す如く長尺棒状の異
物Tが下部ノズル6の流水孔7を通過しようとした場合
でも、上記流水孔7と支持格子3とが形成する経路がく
の字状に屈曲することから、図示の如く異物Tをこの屈
曲した経路にて詰まらせて、これを捕捉することが可能
である。Thus, in the fuel assembly of the embodiment of the present invention having the above-described structure, even if the long rod-shaped foreign matter T tries to pass through the flow hole 7 of the lower nozzle 6 as shown in FIG. Since the path formed by the holes 7 and the support grid 3 is bent in a U-shape, it is possible to clog the foreign matter T in the bent path as shown in the figure and capture it.
【0016】以上、本発明の実施例を説明したが、上記
流水孔7は、円孔以外の形状とすることも可能であり、
また、その穿向角度7aも必ずしも一律に傾斜させる必
要はない。While the embodiment of the present invention has been described above, the water flow hole 7 can be formed in a shape other than a circular hole.
Also, the drilling angle 7a does not necessarily need to be uniformly inclined.
【0017】[0017]
【発明の効果】以上説明したように、本発明のPWR燃
料集合体は、下部ノズル・アダプタプレートの流水孔の
穿向角度を、最下部支持格子の流路方向に対して傾斜せ
しめたものであり、長尺棒状の異物が上記流水孔を通過
しようとした場合でも、この流水孔と支持格子とが形成
する経路がくの字状に屈曲することから、上記異物をこ
の経路で詰まらせて捕捉することができ、これにより燃
料集合体の上記長尺の異物によるトラブルを防止すると
の顕著な効果を奏するものである。As described above, in the PWR fuel assembly of the present invention, the drilling angle of the water holes of the lower nozzle / adapter plate is inclined with respect to the flow direction of the lowermost support grid. Yes, even if a long rod-shaped foreign matter tries to pass through the water flow hole, the path formed by the water flow hole and the support grid bends in a V-shape, so that the foreign matter is caught and caught by this path. This has a remarkable effect of preventing trouble due to the long foreign matter of the fuel assembly.
【図1】本発明実施例燃料集合体の下部ノズル・アダプ
タプレートを示す部分拡大断面図である。FIG. 1 is a partially enlarged sectional view showing a lower nozzle adapter plate of a fuel assembly according to an embodiment of the present invention.
【図2】同実施例図燃料集合体の概要図である。FIG. 2 is a schematic view of a fuel assembly of the embodiment.
【図3】同、燃料集合体の下部ノズルと最下部支持格子
を示す説明図である。FIG. 3 is an explanatory view showing a lower nozzle and a lowermost support grid of the fuel assembly.
【図4】従来例燃料集合体の下部ノズル・アダプタプレ
ートを示す部分拡大断面図である。FIG. 4 is a partially enlarged sectional view showing a lower nozzle adapter plate of a conventional fuel assembly.
【図5】下部炉心板流水孔と下部ノズルの位置関係を示
す説明図である。FIG. 5 is an explanatory view showing a positional relationship between a lower core plate flowing water hole and a lower nozzle.
【図6】従来例の下部ノズルを示す斜視図である。FIG. 6 is a perspective view showing a conventional lower nozzle.
【符号の説明】 1 燃料棒2 シンブル管 3 支持格子 4 燃料棒束部 5 上部ノズル 6 下部ノズル 7 流水孔 7a 流水孔の穿孔角度 8 アダプタプレート 9 格子板 10 支持格子の流路 10a 流路の方向[Description of Signs] 1 fuel rod 2 thimble tube 3 support grid 4 fuel rod bundle part 5 upper nozzle 6 lower nozzle 7 flowing water hole 7a drilling angle of flowing water hole 8 adapter plate 9 grid plate 10 flow path of support grid 10a flow path direction
Claims (1)
プタプレート上に、最下部の支持格子を近接させ、該支
持格子の格子板にて上記流水孔出口を細分化してなるP
WR燃料集合体において、上記流水孔の穿向角度を、上
記支持格子の流路方向に対して傾斜せしめたことを特徴
とする異物対策型PWR燃料集合体。1. A P-type nozzle having a lowermost support grid close to an adapter plate of a lower nozzle having a large number of water holes, wherein the outlet of the water holes is subdivided by the grid plate of the support grid.
In the WR fuel assembly, a foreign matter countermeasure type PWR fuel assembly characterized in that a perforation angle of the water holes is inclined with respect to a flow direction of the support grid.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5314545A JP2807960B2 (en) | 1993-11-18 | 1993-11-18 | Foreign substance countermeasure type PWR fuel assembly |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5314545A JP2807960B2 (en) | 1993-11-18 | 1993-11-18 | Foreign substance countermeasure type PWR fuel assembly |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH07140280A JPH07140280A (en) | 1995-06-02 |
JP2807960B2 true JP2807960B2 (en) | 1998-10-08 |
Family
ID=18054585
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5314545A Expired - Fee Related JP2807960B2 (en) | 1993-11-18 | 1993-11-18 | Foreign substance countermeasure type PWR fuel assembly |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2807960B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109935362B (en) * | 2017-12-19 | 2024-05-14 | 中国原子能科学研究院 | Fuel assembly, lower tube seat thereof and bottom device of fuel assembly |
-
1993
- 1993-11-18 JP JP5314545A patent/JP2807960B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPH07140280A (en) | 1995-06-02 |
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