JPH02151793A - Fuel assembly - Google Patents
Fuel assemblyInfo
- Publication number
- JPH02151793A JPH02151793A JP63307427A JP30742788A JPH02151793A JP H02151793 A JPH02151793 A JP H02151793A JP 63307427 A JP63307427 A JP 63307427A JP 30742788 A JP30742788 A JP 30742788A JP H02151793 A JPH02151793 A JP H02151793A
- Authority
- JP
- Japan
- Prior art keywords
- fuel rod
- end plug
- floating
- fuel
- fixing plate
- 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.)
- Pending
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 70
- 230000002265 prevention Effects 0.000 claims abstract description 10
- 238000010586 diagram Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910052770 Uranium Inorganic materials 0.000 description 3
- 229910052778 Plutonium Inorganic materials 0.000 description 2
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 2
- 229910001093 Zr alloy Inorganic materials 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229910001026 inconel Inorganic materials 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 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
- Fuel-Injection Apparatus (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的］
（産業上の利用分野）
本発明は原子炉の炉心部に装荷される燃料集合体に係わ
り、特に原子炉運転中および輸送中における燃料棒の浮
上がりを防止する技術に関するものである。Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a fuel assembly loaded in the core of a nuclear reactor, and in particular to prevention of floating of fuel rods during reactor operation and transportation. This relates to technology that prevents the rise of
（従来の技術）
一般に沸騰水型原子炉では燃料集合体の燃焼度が増大す
ると炉心上部にプルトニウムが蓄積し、プルトニウムの
蓄積によって原子炉運転停止時には炉心上部の反応度が
炉心下部に比較して高くなる傾向にある。このため、燃
料集合体上部のウラン量をわずかに減少させて水対ウラ
ン比を高くすると運転停止時の無限増倍率Ｋ ｏｏを効
果的に低下させることができ、原子炉の安全性を向上さ
せることができることから、チャンネルボックス内に正
方配列された燃料棒の一部を短尺燃料棒とし、燃料集合
体上部のウラン量を減少させた燃料集合体が特願昭５７
−１２８２１号において提案されている。(Prior art) In general, in a boiling water reactor, as the burnup of the fuel assembly increases, plutonium accumulates in the upper part of the core, and due to the accumulation of plutonium, when the reactor is shut down, the reactivity in the upper part of the core becomes lower than that in the lower part of the core. It tends to be higher. Therefore, by slightly reducing the amount of uranium in the upper part of the fuel assembly to increase the water-to-uranium ratio, the infinite multiplication factor K oo at the time of shutdown can be effectively reduced, improving the safety of the reactor. Because of this, a patent application filed in 1983 proposed a fuel assembly in which some of the fuel rods squarely arranged in the channel box were made into short fuel rods, and the amount of uranium in the upper part of the fuel assembly was reduced.
-12821.
（発明が解決しようとする４届）
しかしながら、このような従来の燃料集合体は短尺燃料
棒の下部のみが下部支持板に支持された構造であるため
、短尺燃料棒が輸送中に下部支持板から脱落したり、原
子炉運転中に浮上ってしまうなどの問題があった。(4 issues to be solved by the invention) However, since such a conventional fuel assembly has a structure in which only the lower part of the short fuel rod is supported by the lower support plate, the short fuel rod is not supported by the lower support plate during transportation. There were problems such as falling off the reactor or floating to the surface during reactor operation.
本発明の目的は上記のような問題点に鑑みてなされたも
のであり、輸送中や原子炉運転中に燃料棒の７ｆ上がり
を防止でき、燃料棒の健全性を向上させることができる
燃料集合体を提供しようとするものである。The object of the present invention has been made in view of the above-mentioned problems, and is to provide a fuel assembly that can prevent fuel rods from rising by 7F during transportation or nuclear reactor operation, and can improve the integrity of fuel rods. It is an attempt to provide the body.
［発明の構成］
（課題を解決するための手段）
上記課題を解決するために本発明は、少なくとも上端が
固定されていない燃料棒の下部端栓に径の細いくびれ部
を設けるとともに、上記燃料棒の下部を支持する下部支
持板と燃料棒下部との間に固定板を設け、この固定板に
上記下部端栓が貫通する大径部と上記くびれ部が嵌合す
る小径部とからなる浮上り防止孔を設けたことを特徴と
するものである。[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides at least a constricted portion with a narrow diameter in the lower end plug of the fuel rod whose upper end is not fixed, and the fuel rod A fixing plate is provided between a lower support plate that supports the lower part of the rod and the lower part of the fuel rod, and the fixing plate has a large diameter part through which the lower end plug penetrates, and a small diameter part into which the constricted part fits. This feature is characterized by the provision of holes to prevent damage.
（作 用）
本発明においては、燃料棒の下部端栓に設けられたくび
れ部を固定板の浮上り防止孔小径部に嵌合させることに
より、燃料棒を固定板に固定することができ、燃料棒の
浮上りを防止できる。(Function) In the present invention, the fuel rod can be fixed to the fixing plate by fitting the constriction provided on the lower end plug of the fuel rod into the small diameter part of the floating prevention hole of the fixing plate. This prevents the fuel rods from floating up.
（実施例）
以下、本発明の一実施例を第１図ないし第７図を参照し
て説明する。(Example) An example of the present invention will be described below with reference to FIGS. 1 to 7.
第１図はｉ’１ｌｔｉ ｌ１ｌｉ！水型原子炉に使用さ
れる燃料集合体の構成を示すもので、図中１は角筒状に
形成されたチャンネルボックスである。このチャンネル
ボックス１内には、多数の燃料棒２・・・を第２図に示
す如く正方配列した燃料束が組込まれている。Figure 1 is i'1lti l1li! This figure shows the configuration of a fuel assembly used in a water reactor, and numeral 1 in the figure is a channel box formed into a rectangular tube shape. This channel box 1 incorporates a fuel bundle in which a large number of fuel rods 2 are arranged in a square arrangement as shown in FIG.
上記燃料棒２・・・のうち長尺燃料棒２Ａは、その上上
端を上部支持板３および下部支持板４で支持されている
とともに、中間部分を複数のスペーサ５によって一定間
隔に保持されている。また、短尺燃料棒２Ｂは第２図に
示す如くチャンネルボックス１の四隅近傍に位置してお
り、下端のみが下部支持板４によって支持されている。Among the fuel rods 2..., the long fuel rods 2A are supported at their upper ends by an upper support plate 3 and a lower support plate 4, and their middle portions are held at regular intervals by a plurality of spacers 5. There is. Further, the short fuel rods 2B are located near the four corners of the channel box 1, as shown in FIG. 2, and only their lower ends are supported by the lower support plate 4.
第３図は短尺燃料棒２Ｂの構造を示す図で、この短尺燃
料棒２Ｂの下部端栓６には径の細いくびれ部６Ａが設け
られている。このくびれ部６Ａは下部支持板４と燃料棒
下部との間に設けられた固定板７に係合するようになっ
ており、固定板７には第４図及び第５図に示す如く下部
端栓先端部６Ｂが貫通する大径部８ａとくびれ部６Ａが
嵌合する小径部８ｂとからなる浮上り防止孔８が形成さ
れている。また、固定板７には長尺燃料棒２Ａの下部端
栓６が貫通する孔９が形成されており、固定板７は長尺
燃料棒２Ａによって固定される構造となっている。なお
、固定板７はステンレス鋼、インコネル、ジルカロイ合
金等で形成されている。FIG. 3 is a diagram showing the structure of the short fuel rod 2B, and the lower end plug 6 of the short fuel rod 2B is provided with a constricted portion 6A having a narrow diameter. This constricted portion 6A is adapted to engage with a fixing plate 7 provided between the lower support plate 4 and the lower part of the fuel rod, and the fixing plate 7 has a lower end as shown in FIGS. 4 and 5. A lifting prevention hole 8 is formed which includes a large diameter part 8a through which the stopper tip 6B passes and a small diameter part 8b into which the constricted part 6A fits. Further, the fixing plate 7 is formed with a hole 9 through which the lower end plug 6 of the long fuel rod 2A passes, and the fixing plate 7 is structured to be fixed by the long fuel rod 2A. Note that the fixing plate 7 is made of stainless steel, Inconel, Zircaloy alloy, or the like.
第６図は短尺燃料棒２Ｂが固定板７に固定された状態を
示したもので、同図に示すようにくびれ部６Ａは浮上り
防１１−孔８の小径部８ｂに嵌合しており、これによっ
て短尺燃料棒２Ｂが固定板７から浮上るのを防止してい
る。FIG. 6 shows the short fuel rod 2B fixed to the fixing plate 7. As shown in the figure, the constricted portion 6A is fitted into the small diameter portion 8b of the anti-floating hole 8. This prevents the short fuel rods 2B from floating up from the fixed plate 7.
第７図は燃料集合体の組立手順を示す図で、まず（ａ）
に示す如く短尺燃料棒２Ｂの下部端栓先端部６Ｂを浮上
り防止孔８の大径部８ａに挿入する。次に（ｂ）に示す
如く短尺燃料棒２Ｂのくびれ部６Ａを浮上り防ＩＬ孔８
の小径部８ａに嵌合させる。そして、（ｃ）に示す如く
短尺燃料棒２の下部端栓６を下部支持板４に挿入した後
、（ｄ）に示す如く長尺燃料棒２Ａの下部端栓６を固定
板７を通して下部支持板４に挿入する。Figure 7 is a diagram showing the assembly procedure of the fuel assembly, first (a).
As shown in the figure, the lower end plug tip 6B of the short fuel rod 2B is inserted into the large diameter portion 8a of the floating prevention hole 8. Next, as shown in (b), the constriction 6A of the short fuel rod 2B floats up to
Fit into the small diameter portion 8a of. After inserting the lower end plug 6 of the short fuel rod 2 into the lower support plate 4 as shown in (c), the lower end plug 6 of the long fuel rod 2A is inserted into the lower support plate 7 through the fixing plate 7 as shown in (d). Insert into plate 4.
このように本実施例においては短尺燃料棒２ｂの下部端
栓６に径の細いくびれ部６Ａを設けるとともに、下部支
持板４と燃料棒下部との間に固定板７を設け、この固定
板７に下部端栓６が貫通ずる大径部８ａとくびれ部６Ａ
が嵌合する小径部８ｂとからなる浮上り防止孔８を設け
たので、短尺燃料棒２ｂの浮上りを防止することができ
る。As described above, in this embodiment, the lower end plug 6 of the short fuel rod 2b is provided with the narrow diameter constriction 6A, and the fixing plate 7 is provided between the lower support plate 4 and the lower part of the fuel rod. The large diameter portion 8a through which the lower end plug 6 passes through and the constricted portion 6A
Since the floating prevention hole 8 consisting of the small diameter portion 8b into which the short fuel rod 2b is fitted is provided, it is possible to prevent the short fuel rod 2b from floating.
なお、本発明は上記実施例に限定されるものではない。Note that the present invention is not limited to the above embodiments.
例えば固定板７は第８図または第９図に示すようなもの
でもよい。また、上記実施例では短尺燃料棒２Ｂの下部
端栓６に（びれ部６Ａを設けたが、少なくとも上端か固
定されていない燃料棒２の下部端栓６にくびれ部６Ａを
設ければよい。For example, the fixing plate 7 may be of the type shown in FIG. 8 or 9. Furthermore, in the embodiment described above, the constricted portion 6A is provided in the lower end plug 6 of the short fuel rod 2B, but the constricted portion 6A may be provided in the lower end plug 6 of the fuel rod 2 whose upper end is not fixed at least.
さらに、上記実施例では沸騰水型原子炉に使用される燃
料集合体について説明したが、加圧水型原子炉に使用さ
れる燃料集合体にも適用できる。Furthermore, although the above embodiments have been described with respect to fuel assemblies used in boiling water reactors, the present invention can also be applied to fuel assemblies used in pressurized water reactors.
［発明の効果〕
以上説明したように本発明は、上端が固定されていない
燃料棒の下部端栓に径の細いくびれ部を設けるとともに
、下部支持板と燃料棒下部との間に固定板を設け、この
固定板に上記下部端栓が貫通する大径部と上記くびれ部
が嵌合する小径部とからなる浮上り防止孔を設けたので
、輸送中や原子炉運転中に燃料棒の浮上りを防止でき、
燃料棒の健全性を向上させることができる燃料集合体を
提供できる。[Effects of the Invention] As explained above, the present invention provides a constricted portion with a narrow diameter in the lower end plug of a fuel rod whose upper end is not fixed, and also provides a fixing plate between the lower support plate and the lower part of the fuel rod. The fixing plate is provided with an anti-floating hole consisting of a large diameter part through which the lower end plug passes and a small diameter part into which the constricted part fits, preventing the fuel rods from floating during transportation or reactor operation. It can prevent
A fuel assembly that can improve the integrity of fuel rods can be provided.
第１図ないし第７図は本発明の一実施例を示すもので、
第１図は燃料集合体の縦断面図、第２図は第１図の■−
■断面図、第３図は短尺燃料棒の正面図、第４図は固定
板の平面図、第５図は第４図の一部拡大図、第６図は短
尺燃料棒が固定板に固定された状態を示す図、第７図は
燃料集合体の組立手順を示す図、第８図及び第９図は固
定板の変形例を示す図である。
１・・・チャンネルボックス、２・・・燃料棒、２Ａ・
・・長尺燃料棒、２Ｂ・・・短尺燃料棒、３・・・上部
支持板、４・・・下部支持板、５・・・スペーサ、６・
・・下部端栓、６Ａ・・・くびれ部、７・・・固定板、
８・・・浮上り防止孔、８ａ・・・大径部、８ｂ・・・
小径部。
出願人代理人 弁理士 鈴江武彦
第２
図
第１
第
図
Ｂ
第
図
Ｂ
ｂ
第５
図
第
図
（ｃ）
第
図1 to 7 show an embodiment of the present invention,
Figure 1 is a longitudinal cross-sectional view of the fuel assembly, and Figure 2 is the ■-
■Cross-sectional view, Figure 3 is a front view of the short fuel rod, Figure 4 is a plan view of the fixing plate, Figure 5 is a partially enlarged view of Figure 4, and Figure 6 is the short fuel rod fixed to the fixing plate. FIG. 7 is a diagram showing the assembly procedure of the fuel assembly, and FIGS. 8 and 9 are diagrams showing modified examples of the fixing plate. 1...Channel box, 2...Fuel rod, 2A・
... Long fuel rod, 2B... Short fuel rod, 3... Upper support plate, 4... Lower support plate, 5... Spacer, 6.
...lower end plug, 6A...constriction, 7...fixing plate,
8...Floating prevention hole, 8a...Large diameter part, 8b...
Small diameter section. Applicant's agent Patent attorney Takehiko Suzue 2 Figure 1 Figure B Figure B b Figure 5 Figure (c) Figure 5
Claims (1)
径の細いくびれ部を設けるとともに、上記燃料棒の下部
を支持する下部支持板と燃料棒下部との間に固定板を設
け、この固定板に上記下部端栓が貫通する大径部と上記
くびれ部が嵌合する小径部とからなる浮上り防止孔を設
けたことを特徴とする燃料棒集合体。At least a narrow diameter constriction is provided in the lower end plug of the fuel rod whose upper end is not fixed, and a fixing plate is provided between the lower support plate supporting the lower part of the fuel rod and the lower part of the fuel rod, and the fixing plate A fuel rod assembly characterized in that a floating prevention hole is provided in the hole, the hole having a large diameter portion through which the lower end plug passes and a small diameter portion into which the constriction portion fits.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63307427A JPH02151793A (en) | 1988-12-05 | 1988-12-05 | Fuel assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63307427A JPH02151793A (en) | 1988-12-05 | 1988-12-05 | Fuel assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02151793A true JPH02151793A (en) | 1990-06-11 |
Family
ID=17968930
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63307427A Pending JPH02151793A (en) | 1988-12-05 | 1988-12-05 | Fuel assembly |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02151793A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008523363A (en) * | 2004-12-09 | 2008-07-03 | アレヴァ エンペー ゲゼルシャフト ミット ベシュレンクテル ハフツング | Boiling water reactor fuel assemblies |
-
1988
- 1988-12-05 JP JP63307427A patent/JPH02151793A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008523363A (en) * | 2004-12-09 | 2008-07-03 | アレヴァ エンペー ゲゼルシャフト ミット ベシュレンクテル ハフツング | Boiling water reactor fuel assemblies |
| US9418766B2 (en) | 2004-12-09 | 2016-08-16 | Areva Gmbh | Fuel assembly for a boiling water reactor |
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