JP2000111681A - Nuclear reactor fuel assembly - Google Patents
Nuclear reactor fuel assemblyInfo
- Publication number
- JP2000111681A JP2000111681A JP10284431A JP28443198A JP2000111681A JP 2000111681 A JP2000111681 A JP 2000111681A JP 10284431 A JP10284431 A JP 10284431A JP 28443198 A JP28443198 A JP 28443198A JP 2000111681 A JP2000111681 A JP 2000111681A
- Authority
- JP
- Japan
- Prior art keywords
- control rod
- rod guide
- fuel assembly
- small diameter
- guide tube
- 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.)
- Withdrawn
Links
- 239000003758 nuclear fuel Substances 0.000 title claims abstract description 5
- 239000000446 fuel Substances 0.000 claims abstract description 24
- 239000002826 coolant Substances 0.000 claims abstract description 6
- 238000005452 bending Methods 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 6
- 238000002485 combustion reaction Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 238000003780 insertion Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000003466 welding Methods 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)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、原子炉において燃
焼に供される燃料集合体に関し、特に加圧水型原子炉用
の燃料集合体における制御棒案内管と下部ノズルとの連
結構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel assembly used for combustion in a nuclear reactor, and more particularly to a connection structure between a control rod guide tube and a lower nozzle in a fuel assembly for a pressurized water reactor.
【０００２】[0002]
【従来の技術】現在広く発電用として使用されている加
圧水型原子炉においては、一般に細い制御棒をクラスタ
状に組み立てた制御棒組立体所謂制御棒クラスタを使用
して炉内核反応を制御することとしている。従って、原
子炉炉心を構成する燃料集合体も、その細い制御棒を受
け入れて案内するための管所謂制御棒案内管を含んで構
成されている。その燃料集合体の一般的な構造を概説す
れば、次のようになる。即ち、原子炉燃料集合体は、多
数の冷却材貫流孔を備え間隔を置いて互いに対向した上
部ノズル及び下部ノズルと、これら両ノズル間を互いに
平行に延び両端が該両ノズルにそれぞれ連結される複数
の制御棒案内管と、この制御棒案内管に沿って間隔をお
いて配設された複数の支持格子と、この支持格子の格子
開口に挿通されて支持される複数の燃料棒とから構成さ
れる。2. Description of the Related Art In a pressurized water reactor which is currently widely used for power generation, a control rod assembly in which thin control rods are assembled in a cluster shape, a so-called control rod cluster, is used to control the nuclear reaction in the reactor. And Therefore, the fuel assembly constituting the nuclear reactor core also includes a tube for receiving and guiding the thin control rod, that is, a control rod guide tube. An outline of the general structure of the fuel assembly is as follows. That is, the reactor fuel assembly has an upper nozzle and a lower nozzle which are provided with a plurality of coolant through-holes and are opposed to each other at intervals, and which extend parallel to each other between the two nozzles and both ends are connected to the nozzles. It comprises a plurality of control rod guide tubes, a plurality of support lattices arranged at intervals along the control rod guide tubes, and a plurality of fuel rods inserted and supported in the lattice openings of the support lattice. Is done.
【０００３】而して、前述の制御棒乃至制御棒クラスタ
は、通常運転時には全体的に炉心の上方に引き上げられ
ているのであるが、異常時には自由落下などにより急速
に挿入されるようになっている。このような緊急挿入時
における制御棒の衝撃を緩和するため、図４に示すよう
に制御棒案内管１の下端部に小径部１aが形成されてい
る。こうすることにより、図示しない制御棒の外周面と
小径部１aの内面との間隙が小さくなり、ダッシュポッ
ト作用が得られる。更に図４を説明すると、小径部１a
の下端に溶接されたねじ付端栓３に取り付けボルト５が
螺合して下部ノズル７と制御棒案内管１とが連結されて
いる。尚、符号９は燃料棒の支持格子である。The above-mentioned control rods or control rod clusters are generally pulled up above the core during normal operation, but are rapidly inserted due to free fall or the like when abnormal. I have. In order to reduce the impact of the control rod during such an emergency insertion, a small diameter portion 1a is formed at the lower end of the control rod guide tube 1 as shown in FIG. By doing so, the gap between the outer peripheral surface of the control rod (not shown) and the inner surface of the small diameter portion 1a is reduced, and a dashpot effect is obtained. Referring further to FIG. 4, the small diameter portion 1a
Attachment bolt 5 is screwed into threaded end plug 3 welded to the lower end of, and lower nozzle 7 and control rod guide tube 1 are connected. Reference numeral 9 denotes a support grid for fuel rods.
【０００４】[0004]
【発明が解決しようとする課題】而して、原子炉運転時
の炉心内は、高温高圧の冷却材が流れ、中性子やガンマ
線などの放射線が存在し厳しい雰囲気にあるが、そこに
装荷された燃料集合体はこれらの影響を直接的に受け
る。従って燃焼が進んで行くと、ボーイング等と称する
撓みが発生してくる。前述のように制御棒案内管１の小
径部１ａは断面係数が小さいので撓みが集中しやすい。
この状況を説明のためかなり誇張して示した図が図５で
ある。前述のように小径部１aの下端は下部ノズル７に
固定されているから、図示のように小径部１aの外形線
は変曲点を持ちやすい。このように制御棒案内管１が変
形すると、制御棒Ｒが挿入されたときに干渉し、必要な
制御棒の挿入が得られなくなったり、制御棒の被覆管が
摩耗損傷して種々の不具合を誘起する虞がある。従っ
て、本発明の課題は、燃焼が進んで燃料集合体に変形が
生じても、制御棒の円滑挿入性を確保できる構造の燃料
集合体を提供することである。In the reactor core during operation of the reactor, a high-temperature and high-pressure coolant flows, and there is a radiation atmosphere such as neutrons and gamma rays. Fuel assemblies are directly affected by these effects. Therefore, as combustion progresses, bending called bowing or the like occurs. As described above, since the small-diameter portion 1a of the control rod guide tube 1 has a small section modulus, the bending tends to concentrate.
FIG. 5 shows this situation in an exaggerated manner for the sake of explanation. As described above, since the lower end of the small diameter portion 1a is fixed to the lower nozzle 7, the outline of the small diameter portion 1a tends to have an inflection point as shown in the figure. When the control rod guide tube 1 is deformed in this way, it interferes when the control rod R is inserted, and the necessary control rod cannot be inserted, or the control rod cladding tube is worn and damaged, causing various problems. There is a risk of induction. Accordingly, an object of the present invention is to provide a fuel assembly having a structure that can ensure smooth insertion of control rods even when the fuel assembly is deformed due to progress of combustion.
【０００５】[0005]
【課題を解決するための手段】如上の課題を解決するた
め、本発明によれば、多数の冷却材貫流孔を備え間隔を
置いて互いに対向した上部ノズル及び下部ノズルと、こ
れら両ノズル間で互いに平行に延び両端がその両ノズル
にそれぞれ連結される複数の制御棒案内管と、同制御棒
案内管に沿って間隔をおいて配設された複数の支持格子
と、同支持格子の格子開口に挿通されて支持される複数
の燃料棒とを有する原子炉燃料集合体において、下部ノ
ズルに下端が固定された前記制御棒案内管の小径部にコ
ルゲート状部を形成して該小径部の曲げ剛性を小さく
し、挿入される制御棒が変形し易い形に変形して、これ
を円滑に受け入れるように構成されていることを特徴と
する。According to the present invention, there is provided, in accordance with the present invention, an upper nozzle and a lower nozzle which are provided with a plurality of coolant flow-through holes and which are opposed to each other at intervals. A plurality of control rod guide tubes extending parallel to each other and having both ends connected to both nozzles thereof; a plurality of support lattices arranged at intervals along the control rod guide tubes; and a lattice opening of the support lattice. A fuel rod having a plurality of fuel rods inserted through and supported by a corrugated portion formed at a small diameter portion of the control rod guide tube having a lower end fixed to a lower nozzle, and bending the small diameter portion. The present invention is characterized in that the rigidity is reduced, and the inserted control rod is deformed into an easily deformable shape, and the control rod is smoothly received.
【０００６】[0006]
【発明の実施の形態】以下添付の図面を参照して本発明
の実施形態を説明する。先ず図２を参照して、本発明が
適用される加圧水型原子炉用燃料集合体１０の全体構造
を説明する。下部ノズル１１は、燃料装荷時に原子炉容
器内の下部炉心板上に接する部分で四隅下面に脚を有
し、原子炉冷却材である軽水が通る多数の貫流孔が穿設
されている。下部ノズル１１に対向する上端位置に上部
ノズル１３があり、同様に多数の軽水貫流孔が形成され
ているが、更に上面縁部にノズルスプリング１３ａが設
けられていて、装荷時に上部炉心板により押圧される。
そして、上部ノズル１３と下部ノズル１１に両端がそれ
ぞれ連結された複数の制御棒案内管１５が互いに平行に
延びている。同様な中空管である計装用案内管１７が燃
料集合体１０の中心部を軸方向に延び、核計装用検出器
の案内に供される。多数の支持格子１９が長手方向に間
隔をおいて制御棒案内管１５に固定されている。制御棒
案内管１５や計装用案内管１７は、支持格子１９の対応
する位置の格子開口に挿通されているのであるが、その
他の格子開口に燃料棒２１が１本づつ挿通されて支持さ
れている。Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an overall structure of a fuel assembly 10 for a pressurized water reactor to which the present invention is applied will be described with reference to FIG. The lower nozzle 11 has legs at four corner lower surfaces at a portion in contact with the lower core plate in the reactor vessel at the time of fuel loading, and has a large number of through-holes through which light water as a reactor coolant passes. An upper nozzle 13 is provided at an upper end position opposite to the lower nozzle 11, and a plurality of light water through-holes are similarly formed. However, a nozzle spring 13a is further provided at an upper surface edge, and is pressed by an upper core plate at the time of loading. Is done.
A plurality of control rod guide tubes 15 each having both ends connected to the upper nozzle 13 and the lower nozzle 11 extend in parallel with each other. An instrumentation guide tube 17, which is a similar hollow tube, extends axially through the center of the fuel assembly 10 and is used to guide a nuclear instrumentation detector. A number of support grids 19 are fixed to the control rod guide tube 15 at longitudinal intervals. The control rod guide tube 15 and the instrumentation guide tube 17 are inserted through the grid openings at the corresponding positions of the support grid 19, and the fuel rods 21 are inserted through the other grid openings one by one and supported. I have.
【０００７】本実施形態の要部が図１に示されている。
図において、制御棒案内管１５の小径部１５ａの下端に
ねじ付端栓２３が溶接により取り付けられ、下部ノズル
１１の取付穴を貫通した取付ボルト２５がねじ付端栓２
３に螺合することにより制御棒案内管１５と下部ノズル
１１が連結されている。そして、小径部１ａの適所に波
状変形部乃至コルゲーション部１５ｂが形成されてい
る。FIG. 1 shows a main part of this embodiment.
In the figure, a threaded end plug 23 is attached to the lower end of the small diameter portion 15a of the control rod guide tube 15 by welding, and a mounting bolt 25 passing through a mounting hole of the lower nozzle 11 is attached to a threaded end plug 2.
3, the control rod guide tube 15 and the lower nozzle 11 are connected. A corrugated portion or corrugated portion 15b is formed at an appropriate position of the small diameter portion 1a.
【０００８】以上のようなコルゲーション部１５ｂを下
端部に持つ制御棒案内管１５を有する燃料集合体１０が
燃焼に供されて曲げ変形した状態を誇張して示すと、図
３のような状態となる。図には燃料棒は示されていない
が、コルゲーション部１５ｂが変形を拘束しないので制
御棒案内管１５はなだらかに全長に渡って弓形に撓んで
いる。このような制御棒案内管１５に制御棒Ｒを挿入す
ると、小径部１ａの内面に倣って図示のようになだらか
に変形する。このように、制御棒Ｒは制御棒案内管１５
に案内されて変形するので、摺動抵抗も少なくなり、円
滑に挿入される。尚、コルゲーション部１５ｂの波の数
は、必要な剛性が得られるように適宜増やしても良いこ
とは勿論である。The state where the fuel assembly 10 having the control rod guide tube 15 having the corrugation portion 15b at the lower end as described above is subjected to combustion and is bent and deformed is exaggerated as shown in FIG. Become. Although the fuel rods are not shown in the figure, the control rod guide tube 15 is smoothly bowed over the entire length since the corrugation portion 15b does not restrain the deformation. When the control rod R is inserted into such a control rod guide tube 15, the control rod R is gently deformed as shown in the figure following the inner surface of the small diameter portion 1a. Thus, the control rod R is connected to the control rod guide tube 15.
, And is deformed, so that the sliding resistance is reduced and it is inserted smoothly. Note that the number of waves of the corrugation portion 15b may be appropriately increased so as to obtain necessary rigidity.
【０００９】[0009]
【発明の効果】以上説明したように、本発明によれば、
燃料集合体の下部ノズルに連結される制御棒案内管の小
径部にコルゲーション部を形成したので、その変形がな
だらかになるから、制御棒もこれに倣って変形し易く、
相互間の摩擦抵抗も少なくなって制御棒が円滑に挿入さ
れる。As described above, according to the present invention,
Since the corrugation part is formed in the small diameter part of the control rod guide tube connected to the lower nozzle of the fuel assembly, the deformation becomes gentle, so the control rod is also easily deformed according to this,
The frictional resistance between them is reduced, and the control rod is inserted smoothly.
【図１】本発明の実施形態の要部を示す概念的断面図で
ある。FIG. 1 is a conceptual sectional view showing a main part of an embodiment of the present invention.
【図２】前記実施形態に係る燃料集合体の一部を切除し
た全体斜視図である。FIG. 2 is an overall perspective view in which a part of the fuel assembly according to the embodiment is cut away.
【図３】前記実施形態の作用説明図である。FIG. 3 is an operation explanatory view of the embodiment.
【図４】従来のものの構造を示す概略部分断面図であ
る。FIG. 4 is a schematic partial sectional view showing the structure of a conventional device.
【図５】従来のものの不具合を説明するための部分断面
図である。FIG. 5 is a partial cross-sectional view for explaining a problem of a conventional device.
１０ 燃料集合体 １１ 下部ノズル １３ 上部ノズル １５ 制御棒案内管 １５ａ 小径部 １５ｂ コルゲーション部 １７ 計装用案内管 １９ 支持格子 ２１ 燃料棒 Ｒ 制御棒 DESCRIPTION OF SYMBOLS 10 Fuel assembly 11 Lower nozzle 13 Upper nozzle 15 Control rod guide tube 15a Small diameter part 15b Corrugation part 17 Instrumentation guide tube 19 Support grid 21 Fuel rod R Control rod
Claims (1)
互いに対向した上部ノズル及び下部ノズルと、同両ノズ
ル間で互いに平行に延び両端が該両ノズルにそれぞれ連
結される複数の制御棒案内管と、同制御棒案内管に沿っ
て間隔をおいて配設された複数の支持格子と、同支持格
子の格子開口に挿通されて支持される複数の燃料棒とを
有する原子炉燃料集合体において、前記下部ノズルに下
端が固定された前記制御棒案内管の小径部にコルゲート
状部を形成して該小径部の曲げ剛性を小さくしているこ
とを特徴とする原子炉燃料集合体。1. An upper nozzle and a lower nozzle which are provided with a plurality of coolant flow-through holes and are opposed to each other at intervals, and a plurality of control rods extending parallel to each other between the nozzles and having both ends connected to the nozzles. A reactor fuel assembly comprising a guide tube, a plurality of support grids arranged at intervals along the control rod guide tube, and a plurality of fuel rods inserted through and supported by the grid openings of the support grid. A reactor fuel assembly, wherein a corrugated portion is formed in a small diameter portion of the control rod guide tube having a lower end fixed to the lower nozzle to reduce the bending rigidity of the small diameter portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10284431A JP2000111681A (en) | 1998-10-06 | 1998-10-06 | Nuclear reactor fuel assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10284431A JP2000111681A (en) | 1998-10-06 | 1998-10-06 | Nuclear reactor fuel assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000111681A true JP2000111681A (en) | 2000-04-21 |
Family
ID=17678472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10284431A Withdrawn JP2000111681A (en) | 1998-10-06 | 1998-10-06 | Nuclear reactor fuel assembly |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000111681A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007515651A (en) * | 2003-12-22 | 2007-06-14 | アレヴァ エヌペ | Terminal end piece for a fuel assembly having a nose for directing a flow of cooling fluid and a corresponding fuel assembly |
-
1998
- 1998-10-06 JP JP10284431A patent/JP2000111681A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007515651A (en) * | 2003-12-22 | 2007-06-14 | アレヴァ エヌペ | Terminal end piece for a fuel assembly having a nose for directing a flow of cooling fluid and a corresponding fuel assembly |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4990304A (en) | Instrumentation tube features for reduction of coolant flow-induced vibration of flux thimble tube | |
| EP0384220B1 (en) | Nuclear fuel-rod support grid | |
| US4777016A (en) | Fuel assembly | |
| US3719560A (en) | Fuel assembly for a nuclear reactor using zirconium alloy clad fuel rods | |
| US5282233A (en) | Low pressure drop easy load end cap | |
| JP3328364B2 (en) | Low pressure drop spacer for nuclear fuel assemblies | |
| US4389369A (en) | Bi-metallic grid for a nuclear reactor fuel assembly | |
| JP2516658B2 (en) | Nuclear fuel rod loading device | |
| EP0290865A2 (en) | Nuclear reactor core containing fuel assemblies positioned adjacent core baffle structure | |
| US4522782A (en) | Fuel assembly for a nuclear reactor | |
| KR930008243B1 (en) | Control rods for boiling water reactor | |
| JP2000111681A (en) | Nuclear reactor fuel assembly | |
| US8243872B2 (en) | Spacer grid for close-spaced nuclear fuel rods | |
| KR20080111409A (en) | Reactor fuel assembly grid | |
| US3425908A (en) | Nuclear fuel assembly | |
| JP3220247B2 (en) | Boiling water reactor fuel assemblies | |
| US9171647B2 (en) | Spacer grid for nuclear fuel assembly for reducing flow-induced vibration | |
| JPS59163589A (en) | Nuclear fuel assembly | |
| JPH11133177A (en) | Nuclear reactor fuel assembly | |
| KR101071287B1 (en) | Internal structure of wire spring type spacer grid | |
| JP2000028770A (en) | Fuel assembly | |
| US5343508A (en) | Spacer grid retainer | |
| JPH08313667A (en) | Reactor fuel assembly and nuclear fuel rod therefor | |
| JP3572163B2 (en) | Reactor control rod | |
| JP3064812B2 (en) | Fuel assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20060110 |