JPH0371673B2 - - Google Patents
Info
- Publication number
- JPH0371673B2 JPH0371673B2 JP57159627A JP15962782A JPH0371673B2 JP H0371673 B2 JPH0371673 B2 JP H0371673B2 JP 57159627 A JP57159627 A JP 57159627A JP 15962782 A JP15962782 A JP 15962782A JP H0371673 B2 JPH0371673 B2 JP H0371673B2
- Authority
- JP
- Japan
- Prior art keywords
- groove
- end plug
- penetration
- amount
- diameter
- 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 - Lifetime
Links
- 239000000446 fuel Substances 0.000 claims description 8
- 238000005253 cladding Methods 0.000 claims description 7
- 239000003758 nuclear fuel Substances 0.000 claims description 7
- 239000008188 pellet Substances 0.000 claims description 5
- 230000035515 penetration Effects 0.000 description 20
- 239000011324 bead Substances 0.000 description 7
- 238000003466 welding Methods 0.000 description 6
- 125000006850 spacer group Chemical group 0.000 description 3
- 229910001093 Zr alloy Inorganic materials 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000002826 coolant Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000004992 fission Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000630 rising effect 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
- Butt Welding And Welding Of Specific Article (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
【発明の詳細な説明】
〔発明の技術分野〕
本発明は原子炉に用いる燃料棒に係り、特に健
全性向上のために下部端栓首部にＵ溝を施した核
燃料棒に関する。DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fuel rod used in a nuclear reactor, and more particularly to a nuclear fuel rod in which a U-groove is formed in the lower end plug neck to improve soundness.
第１図は核燃料棒を示すもので、ジルカロイ製
の被覆管１内には燃料ペレツト２が上下方向に積
層充填されているとともに、被覆管１の上下開口
部は、ジルカロイ製の端栓３，４によつて溶接密
封されている。そして燃料棒内のガス圧が過度に
上昇するのを防止するため被覆管１内上部にプレ
ナム５が設けられ、このプレナム５内には、輸送
時のペレツト２の移動を防止するためステンレス
鋼製のプレナムスプリング６が配設されている。
FIG. 1 shows a nuclear fuel rod, in which a Zircaloy cladding tube 1 is filled with fuel pellets 2 stacked vertically, and the upper and lower openings of the cladding tube 1 are filled with Zircaloy end plugs 3, 4 is welded and sealed. In order to prevent the gas pressure within the fuel rods from rising excessively, a plenum 5 is provided at the upper part of the cladding tube 1, and within this plenum 5, stainless steel pellets are installed to prevent the pellets 2 from moving during transportation. A plenum spring 6 is provided.
燃料棒の下部端栓溶接部は、核分裂生成物を冷
却材中に漏洩させないために十分な強度が必要で
あり、良好な溶接溶け込みが要求される。而る
に、下部端栓部は燃料集合体組立時に第２図に示
す格子状のスペーサ７を通過するため、溶接ビー
トが過度に大きくなると、セル８を変形させ、好
ましくない。 The lower end plug welds of fuel rods must have sufficient strength to prevent fission products from leaking into the coolant, and require good weld penetration. However, since the lower end plug portion passes through the lattice-shaped spacer 7 shown in FIG. 2 during assembly of the fuel assembly, if the welding beat becomes too large, the cell 8 will be deformed, which is undesirable.
上述のように、下部端栓溶接部には相反する要
求が加わるため、製造技術的に難しい問題があ
る。そこで、従来は第３図に示すように下部端栓
４にＶ溝９を施し、溶接時に熱がシヤンク部１０
に逃げにくいような対策を講じていた。このＶ溝
は、Ｖ溝部の底部である最細部の長さがＶ溝を施
した部分の長さと比べ非常に短いもしくは一点で
あることを特徴としている。しかしながら、これ
による効果は十分ではなく、逃げる熱を補うため
にさらに入熱量を増加させる必要が生じ、その結
果として溶接溶け込みは十分でもビード径が大き
過ぎるという不具合の発生がしばしば起こつた。 As mentioned above, the lower end plug weld is subject to conflicting requirements and therefore poses difficult manufacturing problems. Therefore, conventionally, as shown in FIG.
Measures were taken to make it difficult for them to escape. This V-groove is characterized in that the length of the lowest part, which is the bottom of the V-groove portion, is much shorter than the length of the portion where the V-groove is formed, or is just one point. However, this effect was not sufficient, and it became necessary to further increase the amount of heat input to compensate for the heat escaping.As a result, even if weld penetration was sufficient, the bead diameter was often too large.
下部端栓溶接部は十分な溶け込みを有すると共
に大きなビードを形成してはならない。このよう
な相反する要求を満たすためには、溶接時に熱が
先端部（シヤンク部１０）に逃げることを防止
し、熱を溶接部に集中させることによつて入熱量
を減少させるように下部端栓を設計する必要があ
る。而るに、一方では下部端栓には十分な機械的
強度が要求されるため、端栓首部の径を徒らに小
さくすることはできない。
The lower end plug weld shall have sufficient penetration and shall not form a large bead. In order to satisfy these conflicting demands, it is necessary to prevent heat from escaping to the tip (shank part 10) during welding, and to reduce the amount of heat input by concentrating the heat in the welding part. It is necessary to design a stopper. However, since the lower end plug is required to have sufficient mechanical strength, the diameter of the neck of the end plug cannot be reduced unnecessarily.
本発明は上述の点を鑑みてなされたもので、適
切な溶接部を形成するための下部端栓を提供する
ものである。 The present invention has been made in view of the above points, and provides a lower end plug for forming a suitable weld.
第４図は本発明の核燃料棒を示すもので、下部
端栓１１の他は全て従来のものと同一である。下
部端栓１１の首部には従来のＶ溝に代つてＵ溝が
施されている。この詳細を第５図に示す。このＵ
溝は、Ｕ溝部の底部である最細部の長さがＵ溝を
施した部分の長さと比べほとんど同じか少し短い
長さとなつている。而して、本発明によれば、従
来のＶ溝の場合よりもシヤンク部１０への熱伝達
率が小さくなるため、溶接時に加えられる熱は溶
接部に集中され、溶け込み特性の向上がなされ
る。
FIG. 4 shows a nuclear fuel rod according to the present invention, in which everything except the lower end plug 11 is the same as the conventional one. The neck of the lower end stopper 11 is provided with a U-groove instead of the conventional V-groove. The details are shown in FIG. This U
The length of the smallest part of the groove, which is the bottom of the U-groove portion, is almost the same or slightly shorter than the length of the portion where the U-groove is formed. According to the present invention, the heat transfer coefficient to the shank portion 10 is lower than in the case of a conventional V-groove, so the heat applied during welding is concentrated in the welded portion, and the penetration characteristics are improved. .
Ｕ溝とＶ溝を有する２種類の下部端栓について
溶接実験を実施し、溶け込み特性を比較した。第
６図は実験結果で溶接ビード径と第７図に示す溶
け込み量の関係を示すものである。試験条件は両
者ほぼ同一であるにも拘らず、両者溶け込み特性
には顕著な差が認められる。Ｖ溝、Ｕ溝いずれの
場合にもビード径が大きくなれば溶け込み量も増
加するか、Ｖ溝の場合には曲線１４に従うのに対
してＵ溝の場合には曲線１３に従う。換言すれ
ば、同じ溶け込みに対してＶ溝の方がＵ溝よりも
ビード径が大きくなり、Ｕ溝の方が溶け込み特性
は良好である。 Welding experiments were conducted on two types of lower end plugs, one with a U-groove and the other with a V-groove, and the penetration characteristics were compared. FIG. 6 is an experimental result showing the relationship between the weld bead diameter and the penetration amount shown in FIG. 7. Even though the test conditions are almost the same for both, there is a noticeable difference in the penetration characteristics of the two. In both cases of V-groove and U-groove, as the bead diameter increases, the amount of penetration also increases, or in the case of V-groove, it follows curve 14, whereas in the case of U-groove, it follows curve 13. In other words, for the same penetration, the V-groove has a larger bead diameter than the U-groove, and the U-groove has better penetration characteristics.
更に異なるＵ溝について溶接実験を行つた。こ
こで第５図に示すようにＵ溝の最細部の長さＬ、
このＵ溝最細部の下部端栓直径をＤとし、このＵ
溝の長さＬとＵ溝部下部端栓直径Ｄを２乗の比
D2／Ｌに着目した。第７図は実験結果であり、
溶接ビード径を同一にした場合のD2／Ｌと溶け
込み量の関係を示すものである。曲線１５，１
６，１７はそれぞれＤ＝５mm、７mm、10mmの場合
のD2／Ｌと溶け込み量の関係を表している。Ｄ
を小さくすれば端部への熱の逃げが小さくなるた
め、溶け込み量は大きくなるが、D2／Ｌに着目
した場合、その値が35以上になるとＤの値に係ら
ず、端部への熱の逃げが大きくなり、溶け込み量
は急激に減少する。 Furthermore, welding experiments were conducted using different U-grooves. Here, as shown in FIG. 5, the length L of the deepest part of the U groove,
The diameter of the lower end plug at the deepest part of this U groove is D, and this U
Ratio of groove length L to U groove lower end plug diameter D to the second power
We focused on D 2 /L. Figure 7 shows the experimental results.
It shows the relationship between D 2 /L and penetration amount when the weld bead diameter is the same. curve 15,1
6 and 17 represent the relationship between D 2 /L and penetration amount when D=5 mm, 7 mm, and 10 mm, respectively. D
If D is made smaller, the amount of heat escaping to the edges will be smaller, which will increase the amount of melting, but if we focus on D 2 /L, if the value is 35 or more, the amount of heat to the edges will decrease regardless of the value of D. Heat escape increases and the amount of melting decreases rapidly.
本発明は下部端栓首部にＵ溝を施し、また
D2／Ｌを35以下としているため、上述の理由に
よつて溶接溶け込み性が著しく向上して、不良率
の低減を図ることができると同時に燃料棒の機械
的健全性を向上させることができる。 The present invention has a U-groove on the lower end stopper neck, and
Since D 2 /L is 35 or less, weld penetration is significantly improved for the reasons mentioned above, reducing the defective rate and at the same time improving the mechanical integrity of the fuel rod. .
第１図は従来の核燃料棒を１部側面で示す断面
図、第２図は従来のスペーサの平面図、第３図は
従来の下部端栓を示す側面図、第４図は本発明の
核燃料棒を１部側面で示す断面図、第５図は本発
明の下部端栓を示す側面図、第６図はビード径と
溶け込み量の関係を示す試験結果、第７図は溶け
込み量の位置を示す図、第８図はD2／Ｌと溶け
込み量の関係を示す試験結果である。
１……被覆管、２……燃料ペレツト、３……上
部端栓、４……下部端栓、５……プレナム、６…
…プレナムスプリング、７……スペーサ、８……
セル、９……Ｖ溝、１０……シヤンク部、１１…
…下部端栓、１２……Ｕ溝、１３……Ｕ溝下部端
栓の溶け込み特性、１４……Ｖ溝下部端栓の溶け
込み特性、１５……直径５mmの場合の溶け込み特
性、１６……直径７mmの場合の溶け込み特性、１
７……直径10mmの場合の溶け込み特性。
Fig. 1 is a cross-sectional view showing a part of a conventional nuclear fuel rod from the side, Fig. 2 is a plan view of a conventional spacer, Fig. 3 is a side view showing a conventional lower end plug, and Fig. 4 is a nuclear fuel of the present invention. 5 is a side view showing the lower end plug of the present invention, FIG. 6 is a test result showing the relationship between bead diameter and penetration amount, and FIG. 7 is a diagram showing the position of penetration amount. The diagram shown in FIG. 8 shows test results showing the relationship between D 2 /L and penetration amount. DESCRIPTION OF SYMBOLS 1... Cladding tube, 2... Fuel pellet, 3... Upper end plug, 4... Lower end plug, 5... Plenum, 6...
...Plenum spring, 7...Spacer, 8...
Cell, 9...V groove, 10...shank portion, 11...
... lower end plug, 12 ... U groove, 13 ... penetration characteristics of U groove lower end plug, 14 ... penetration characteristics of V groove lower end plug, 15 ... penetration characteristics when diameter is 5 mm, 16 ... diameter Penetration characteristics for 7mm, 1
7... Melt characteristics when the diameter is 10 mm.
Claims (1)
填された燃料ペレツトと、被覆管の両端部をそれ
ぞれ密封する端栓とを具備する核燃料棒におい
て、前記下部端栓首部にＵ溝を施し、このＵ溝最
細部の長さＬと前記Ｕ溝最細部の下部端栓直径Ｄ
の２乗の比D2／Ｌを35以下にしたことを特徴と
する核燃料棒。1. In a nuclear fuel rod comprising a cladding tube, fuel pellets stacked and filled in the cladding tube in the vertical direction, and end plugs that seal both ends of the cladding tube, a U-groove is formed in the neck of the lower end plug, The length L of the U-groove's deepest part and the diameter D of the lower end plug of the U-groove's deepest part
A nuclear fuel rod characterized in that the ratio of the square of D 2 /L is 35 or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57159627A JPS5950386A (en) | 1982-09-16 | 1982-09-16 | Nuclear fuel rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57159627A JPS5950386A (en) | 1982-09-16 | 1982-09-16 | Nuclear fuel rod |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5950386A JPS5950386A (en) | 1984-03-23 |
| JPH0371673B2 true JPH0371673B2 (en) | 1991-11-14 |
Family
ID=15697847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57159627A Granted JPS5950386A (en) | 1982-09-16 | 1982-09-16 | Nuclear fuel rod |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5950386A (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0110633Y2 (en) * | 1980-03-28 | 1989-03-27 |
-
1982
- 1982-09-16 JP JP57159627A patent/JPS5950386A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5950386A (en) | 1984-03-23 |
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