JPH02154193A - Fuel assembly - Google Patents
Fuel assemblyInfo
- Publication number
- JPH02154193A JPH02154193A JP63307830A JP30783088A JPH02154193A JP H02154193 A JPH02154193 A JP H02154193A JP 63307830 A JP63307830 A JP 63307830A JP 30783088 A JP30783088 A JP 30783088A JP H02154193 A JPH02154193 A JP H02154193A
- Authority
- JP
- Japan
- Prior art keywords
- end plug
- fuel
- insertion hole
- fuel element
- tie 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
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】
〔産業上の利用分野〕
本発明は、原子力発電所、あるいは、照射後試験施設に
おける燃料集合体に係り、特に、燃料要素を下部タイプ
レートから容易に引抜くのに好適な燃料集合体に関する
。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to fuel assemblies in nuclear power plants or post-irradiation test facilities, and in particular to fuel assemblies for easily withdrawing fuel elements from lower tie plates. Concerning a preferred fuel assembly.
従来の燃料集合体の構造を第２図及び第３図に示す。第
３図において、この燃料集合体は複数本の燃料要素８を
支持格子１０．および、上・下部タイプレート１１，５
により支持する構造となっている。第２図において、燃
料要素８は下部タイプレート５の下部端栓１の端栓挿入
孔７のテーパ部９によって支持されている。The structure of a conventional fuel assembly is shown in FIGS. 2 and 3. In FIG. 3, this fuel assembly has a plurality of fuel elements 8 supported by a support grid 10. And upper/lower tie plate 11,5
The structure is supported by In FIG. 2, the fuel element 8 is supported by the tapered portion 9 of the end plug insertion hole 7 of the lower end plug 1 of the lower tie plate 5.
原子炉で使用した燃料集合体を燃料要素単位で検査する
場合には、上部タイプレートを取り外し、燃料要素の上
部端栓を治具で掴み上方へ吊り上げて燃料集合体から燃
料要素を引抜く必要がある。When inspecting a fuel assembly used in a nuclear reactor on a fuel element basis, it is necessary to remove the upper tie plate, grasp the upper end plug of the fuel element with a jig, lift it upward, and pull out the fuel element from the fuel assembly. There is.
従来、燃料集合体では、燃料要素の下部端栓の表面腐食
や燃料要素と下部端栓の取り付は誤差のために、下部タ
イプレートの下部端栓挿入孔と燃料要素下部端栓との間
隙がなくなり、燃料要素引抜き時にこの接触面で過大な
引抜力を要することがある。このため、燃料要素の解体
で燃料要素および下部タイプレートに損傷を与えること
があるので、安全な引抜方法が望まれていた。なお、従
来型の燃料集合体から燃料要素を引抜く方法には下部タ
イプレートを加熱して熱膨張差を利用する方法として特
開昭６０−２０２３９４号公報がある。Conventionally, in fuel assemblies, the gap between the lower end plug insertion hole of the lower tie plate and the lower end plug of the fuel element has been reduced due to surface corrosion of the lower end plug of the fuel element and errors in the installation of the fuel element and the lower end plug. When the fuel element is pulled out, an excessive pulling force may be required at this contact surface. For this reason, since disassembling the fuel element may damage the fuel element and the lower tie plate, a safe extraction method has been desired. Note that Japanese Patent Application Laid-Open No. 60-202394 discloses a conventional method for extracting a fuel element from a fuel assembly, in which the lower tie plate is heated and the difference in thermal expansion is utilized.
上記従来技術は、燃料集合体を原子炉内で使用中に、燃
料要素の下部端栓と下部タイプレートの下部端栓挿入孔
に生じる酸化膜による燃料要素下部端栓と下部タイプレ
ートの下部端栓挿入孔の固着について考慮がされておら
ず、燃焼度の進んだ燃料集合体の照射後試験で燃料要素
を引抜く場合、燃料要素に過度の力を加えなければなら
ず、燃料要素の安全な取り扱いが難かしいなどの問題が
あった。In the above conventional technology, the lower end plug of the fuel element and the lower end of the lower tie plate are caused by an oxide film formed in the lower end plug of the fuel element and the lower end plug insertion hole of the lower tie plate while the fuel assembly is used in a nuclear reactor. No consideration has been given to the sticking of the plug insertion hole, and if the fuel element is to be pulled out during post-irradiation testing of a fuel assembly with advanced burnup, excessive force must be applied to the fuel element, resulting in the safety of the fuel element. There were problems such as difficulty in handling.
本発明の目的は、燃料集合体からの燃料要素の引抜きを
安全、かつ、容易にすることにある。An object of the present invention is to make the extraction of fuel elements from a fuel assembly safe and easy.
上記目的は、燃料要素下部端栓のシャンク部、あるいは
、下部タイプレートの下部端栓挿入孔にテーパを設けて
、生成した酸化膜による固着を防ぐことにより達成され
る。The above object is achieved by providing a taper in the shank portion of the fuel element lower end plug or in the lower end plug insertion hole of the lower tie plate to prevent sticking due to the generated oxide film.
燃料要素の下部端栓シャンク部のテーパ、あるいは、下
部タイプレートの下部端栓挿入孔のテーパは、燃料要素
の下部端栓、または、下部タイプレートの下部端栓挿入
孔に酸化膜の生成付着が生じた場合にも下部端栓シャン
ク部と下部端栓の挿入孔の間隙の減少はわずかであり、
間隙を確保することによって固着を防ぐように作用する
。また、燃料要素の下部端栓の下方が細径のため、燃料
集合体の組立時に下部タイプレートへの燃料要素の挿入
が容易となるように作用する。The taper of the lower end plug shank of the fuel element or the taper of the lower end plug insertion hole of the lower tie plate is caused by the formation of an oxide film on the lower end plug of the fuel element or the lower end plug insertion hole of the lower tie plate. Even when this occurs, the gap between the lower end plug shank and the insertion hole of the lower end plug decreases only slightly.
It acts to prevent sticking by ensuring a gap. Further, since the lower portion of the lower end plug of the fuel element has a smaller diameter, the fuel element can be easily inserted into the lower tie plate when assembling the fuel assembly.
以下、本発明の一実施例を第１図により説明する。 An embodiment of the present invention will be described below with reference to FIG.
燃料要素は、下部端栓１、上部端栓２、被覆管３、燃料
ペレット４から構成される。この燃料要素は、燃料集合
体の下部タイプレート５の下部端栓挿入孔７に挿入され
、組み立てられている。下部端栓１のシャンク部６、あ
るいは、下部タイプレートの下部端栓挿入孔７にテーパ
を設ける。通常は、燃料が進むにつれて、下部端栓のシ
ャンク部、または、下部タイプレートの端栓挿入孔に酸
化膜に生成付着が生じ、下部端栓シャンク部と端栓挿入
孔の間隙が消失し、固着が生じるが本実施例によれば、
燃焼が進んでも間隙を確保することができるので固着を
防ぐことができ、下部タイプレートの引抜きを安全、か
つ、容易に実施できる効果がある。また、本実施例によ
れば、燃料要素の下部端栓の下方が細径なため、燃料要
素を下部タイプレートの挿入孔へ容易に挿入できる効果
がある。The fuel element is composed of a lower end plug 1, an upper end plug 2, a cladding tube 3, and fuel pellets 4. This fuel element is inserted into the lower end plug insertion hole 7 of the lower tie plate 5 of the fuel assembly and assembled. The shank portion 6 of the lower end plug 1 or the lower end plug insertion hole 7 of the lower tie plate is tapered. Normally, as the fuel advances, an oxide film forms and adheres to the shank of the lower end plug or the end plug insertion hole of the lower tie plate, and the gap between the lower end plug shank and the end plug insertion hole disappears. Although sticking occurs, according to this example,
Since a gap can be maintained even as combustion progresses, sticking can be prevented, and the lower tie plate can be pulled out safely and easily. Further, according to this embodiment, since the lower end plug of the fuel element has a small diameter, the fuel element can be easily inserted into the insertion hole of the lower tie plate.
本害施例では下部端栓のシャンク部または挿入孔のいず
れかにテーパを設けたが、この両方にテーパを設けても
、もちろん、同じ効果を得られる。In this embodiment, a taper is provided on either the shank portion or the insertion hole of the lower end plug, but the same effect can of course be obtained by providing a taper on both.
本発明によれば、燃料集合体からの燃料要素の引抜きを
安全、かつ、容易に実施することができる。According to the present invention, a fuel element can be safely and easily extracted from a fuel assembly.
また、燃料要素を下部タイプレートの下部端栓挿入孔へ
容易に挿入することができる。Further, the fuel element can be easily inserted into the lower end plug insertion hole of the lower tie plate.
第１図は本発明の一実施例の下部タイプレートと下部端
栓との嵌合部及び燃料要素の接触部構成図、第２図は従
来の下部タイプレートと下部端栓との嵌合部の構成図、
第３図は燃料集合体の部分断面図である。Fig. 1 is a structural diagram of the fitting part between the lower tie plate and the lower end plug and the contact part of the fuel element according to an embodiment of the present invention, and Fig. 2 is the fitting part of the conventional lower tie plate and the lower end plug. Configuration diagram,
FIG. 3 is a partial sectional view of the fuel assembly.
Claims (1)
イプレートの前記下部端栓の挿入孔にテーパを設けるこ
とを特徴とする燃料集合体。[Claims] 1. A fuel assembly for a nuclear reactor, characterized in that a shank portion of a lower end plug of a fuel element and/or an insertion hole for the lower end plug of a lower tie plate is provided with a taper. body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63307830A JPH02154193A (en) | 1988-12-07 | 1988-12-07 | Fuel assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63307830A JPH02154193A (en) | 1988-12-07 | 1988-12-07 | Fuel assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02154193A true JPH02154193A (en) | 1990-06-13 |
Family
ID=17973719
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63307830A Pending JPH02154193A (en) | 1988-12-07 | 1988-12-07 | Fuel assembly |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02154193A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2765028A1 (en) * | 1997-06-23 | 1998-12-24 | Framatome Sa | Reshaping procedure for nuclear reactor fuel rod stopper |
-
1988
- 1988-12-07 JP JP63307830A patent/JPH02154193A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2765028A1 (en) * | 1997-06-23 | 1998-12-24 | Framatome Sa | Reshaping procedure for nuclear reactor fuel rod stopper |
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