JPH0455793A - Nuclear fuel assembly - Google Patents
Nuclear fuel assemblyInfo
- Publication number
- JPH0455793A JPH0455793A JP2165622A JP16562290A JPH0455793A JP H0455793 A JPH0455793 A JP H0455793A JP 2165622 A JP2165622 A JP 2165622A JP 16562290 A JP16562290 A JP 16562290A JP H0455793 A JPH0455793 A JP H0455793A
- Authority
- JP
- Japan
- Prior art keywords
- end plug
- nuclear fuel
- insertion hole
- fuel assembly
- fuel element
- 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
- 239000003758 nuclear fuel Substances 0.000 title claims abstract description 49
- 239000000498 cooling water Substances 0.000 claims description 6
- 238000003780 insertion Methods 0.000 abstract description 18
- 230000037431 insertion Effects 0.000 abstract description 18
- 238000005260 corrosion Methods 0.000 abstract description 6
- 230000007797 corrosion Effects 0.000 abstract description 6
- 239000000446 fuel Substances 0.000 abstract description 4
- 238000000034 method Methods 0.000 abstract description 2
- 239000002826 coolant Substances 0.000 abstract 3
- 230000000712 assembly Effects 0.000 description 3
- 238000000429 assembly Methods 0.000 description 3
- 238000011109 contamination Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002285 radioactive effect Effects 0.000 description 2
- 229910001093 Zr alloy Inorganic materials 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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】
〔産業上の利用分野〕
本発明は、沸騰水型原子炉用の核燃料集合体に係り、特
に照射後試験施設において、前記核燃料集合体から核燃
料要素を引き抜くのに最適な構造の核燃料集合体に関す
るものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a nuclear fuel assembly for a boiling water reactor, and is particularly suitable for extracting nuclear fuel elements from the nuclear fuel assembly in a post-irradiation test facility. It concerns a nuclear fuel assembly with a similar structure.
核燃料集合体は、複数の核燃料要素をその上部端栓およ
び下部端栓においてそれぞれ上部タイプレートおよび下
部タイプレートで保持して構成されている。A nuclear fuel assembly is constructed by holding a plurality of nuclear fuel elements at their upper and lower end plugs with an upper tie plate and a lower tie plate, respectively.
ところで、従来の核燃料集合体は、原子炉内で使用中に
下部タイプレートの端栓挿入孔と下部端栓との嵌合部で
、ジルコニウム合金製の下部端栓の表面に腐食（主に酸
化物）を生じ、下部タイプレートの端栓挿入孔と下部端
栓との接触面が固着する。その結果照射後試験施設にお
いて、核燃料集合体から核燃料要素を引き抜くことがで
きないことがあった。上記のような状態で無理に核燃料
要素を引き抜けば、過大な力を要するのみならず、核燃
料要素に損傷を与え、放射能汚染などの危険を伴うこと
もある。このため常に安全で、容易に核燃料要素の引き
抜きのできる構造の核燃料集合体が望まれていた。By the way, when conventional nuclear fuel assemblies are used in a nuclear reactor, the surface of the zirconium alloy lower end plug is corroded (mainly oxidized) at the fitting part between the end plug insertion hole of the lower tie plate and the lower end plug. ), and the contact surface between the end plug insertion hole of the lower tie plate and the lower end plug is fixed. As a result, it was sometimes impossible to extract nuclear fuel elements from nuclear fuel assemblies at post-irradiation test facilities. If the nuclear fuel element is forcibly pulled out under the above conditions, not only will excessive force be required, but the nuclear fuel element may be damaged and there may be risks such as radioactive contamination. For this reason, there has been a desire for a nuclear fuel assembly that is always safe and has a structure that allows for easy extraction of nuclear fuel elements.
上記問題点を解決する方法として、第３図に示す核燃料
要素が提案されている（特開昭６４−２０４９１号公報
）、すなわち第３図において、１１は下部タイプレート
、１２は核燃料要素の下部端栓、１３は下部タイプレー
トの端栓挿入孔、 １４は下部端栓のテーパ部、１５は
核燃料要素であり、下部端栓の平行部とテーパ部との境
界近傍で円周に沿って溝２ａを設け、下部タイプレート
の下部端栓挿入孔１３と下部端栓１２との固着を防止し
ようとしている。As a method to solve the above problem, a nuclear fuel element shown in Fig. 3 has been proposed (Japanese Patent Application Laid-Open No. 64-20491). In Fig. 3, 11 is the lower tie plate, 12 is the lower part of the nuclear fuel element. An end plug, 13 is an end plug insertion hole in the lower tie plate, 14 is a tapered part of the lower end plug, and 15 is a nuclear fuel element, which has a groove along the circumference near the boundary between the parallel part and the tapered part of the lower end plug. 2a is provided to prevent the lower end plug insertion hole 13 of the lower tie plate from sticking to the lower end plug 12.
（発明が解決しようとする問題点〕
しかしながら、上記従来技術は、下部タイプレートの端
栓挿入孔と核燃料要素下部端栓との固着を防止するのに
有効な一つの手段ではあるが。(Problems to be Solved by the Invention) However, the above-mentioned prior art is an effective means for preventing the end plug insertion hole of the lower tie plate from sticking to the lower end plug of the nuclear fuel element.
端栓挿入孔は下部端栓によって完全に塞がれており、燃
料部からの熱伝導により下部端栓の温度が上昇し１表面
腐食を増加させるという欠点があった。The end plug insertion hole is completely blocked by the lower end plug, and there is a drawback that the temperature of the lower end plug increases due to heat conduction from the fuel section, increasing surface corrosion.
本発明は上記状況に対処してなされたもので、本発明の
目的は、核燃料要素下部端栓に生ずる腐食を抑制するこ
とによって、下部タイプレートの端栓挿入孔と核燃料要
素下部端栓との固着を防止し、かつ現在開発が進められ
ている高燃焼度燃料のように、従来よりさらに長期間の
使用および大幅な燃焼度の上昇が見込まれている核燃料
集合体においても、核燃料要素の引き抜きを安全かつ容
易に行うことができる核燃料集合体を提供することにあ
る。The present invention has been made in response to the above-mentioned situation, and an object of the present invention is to suppress the corrosion that occurs in the lower end plug of the nuclear fuel element so that the end plug insertion hole of the lower tie plate and the lower end plug of the nuclear fuel element can be connected to each other. It is possible to prevent sticking of nuclear fuel elements even in nuclear fuel assemblies that are expected to be used for a longer period of time and have a significantly higher burnup, such as the high burnup fuel currently being developed. The object of the present invention is to provide a nuclear fuel assembly that can safely and easily perform the following steps.
すなわち本発明は、上部および下部端栓を有する複数の
核燃料要素と、これらを支える上部および下部タイプレ
ートとを備えた核燃料集合体において、下部端栓に複数
の溝を設けて下部端栓と下部タイプレートとの間に冷却
水流路を形成したことを特徴とする核燃料集合体に関す
る。That is, the present invention provides a nuclear fuel assembly including a plurality of nuclear fuel elements having upper and lower end plugs and upper and lower tie plates supporting them, in which a plurality of grooves are provided in the lower end plug to connect the lower end plugs and the lower tie plate. The present invention relates to a nuclear fuel assembly characterized in that a cooling water flow path is formed between the tie plate and the tie plate.
本発明は下部端栓に複数の溝を設けて下部端栓と下部タ
イプレートとの間に複数の冷却水流路を形成したので、
燃料部からの熱伝導による下部端栓の温度上昇を抑え、
その結果原子炉内での長期間の使用によって生ずる下部
端栓の表面腐食を抑制することができ、端栓挿入孔と下
部端栓との固着を防止することができる。また、下部端
栓に複数の溝を設けたことによって端栓挿入孔と下部端
栓との接触面積が大幅に減少し、万が一固着した場合で
も引き抜きに際して核燃料要素に損傷を与えるような過
大な力を必要としない、したがって本発明の核燃料集合
体では、核燃料要素の引き抜きを安全かつ容易に行うこ
とができる。The present invention provides a plurality of grooves in the lower end plug to form a plurality of cooling water flow paths between the lower end plug and the lower tie plate.
Suppresses the temperature rise of the lower end plug due to heat conduction from the fuel section,
As a result, surface corrosion of the lower end plug caused by long-term use in a nuclear reactor can be suppressed, and sticking between the end plug insertion hole and the lower end plug can be prevented. In addition, by providing multiple grooves in the lower end plug, the contact area between the end plug insertion hole and the lower end plug is significantly reduced, and even if the end plug becomes stuck, excessive force that could damage the nuclear fuel element when pulled out is avoided. Therefore, in the nuclear fuel assembly of the present invention, the nuclear fuel element can be safely and easily extracted.
以下本発明の実施例を第１図および第２図を用いて説明
する。Embodiments of the present invention will be described below with reference to FIGS. 1 and 2.
第１図は、本発明の一実施例である核燃料集合体の核燃
料要素の下部端栓と下部タイプレートとの嵌合部分の縦
断面図であり、第２図は第１図のＡ−Ａ線に沿う横断面
図である。第１図および第２図において、 ２Ａは下部
端栓２に設けた溝、３は端栓挿入孔、５は核燃料要素で
ある。FIG. 1 is a longitudinal sectional view of a fitting portion between a lower end plug of a nuclear fuel element and a lower tie plate of a nuclear fuel assembly according to an embodiment of the present invention, and FIG. FIG. In FIGS. 1 and 2, 2A is a groove provided in the lower end plug 2, 3 is an end plug insertion hole, and 5 is a nuclear fuel element.
第１図に示すように、核燃料要素５は下部タイプレート
１の端栓挿入孔３に挿入され組立られているが、下部端
栓２にはその先端方向から端栓テーバ部４に至る複数の
溝２Ａが設けられている。核燃料要素５を下部タイプレ
ート１の端栓挿入孔３に挿入したとき、下部端栓２と端
栓挿入孔３との間に、第２図に示すように冷却水流路６
が形成され、常に原子炉冷却水によって下部端栓２が冷
却されるようになっている。したがって下部端栓２の温
度上昇および表面腐食の増加が抑制され、下部端栓２と
下部タイプレート１との固着を防止することができる。As shown in FIG. 1, the nuclear fuel element 5 is inserted into the end plug insertion hole 3 of the lower tie plate 1 and assembled. A groove 2A is provided. When the nuclear fuel element 5 is inserted into the end plug insertion hole 3 of the lower tie plate 1, a cooling water flow path 6 is formed between the lower end plug 2 and the end plug insertion hole 3 as shown in FIG.
is formed so that the lower end plug 2 is always cooled by reactor cooling water. Therefore, a temperature rise and an increase in surface corrosion of the lower end plug 2 are suppressed, and it is possible to prevent the lower end plug 2 and the lower tie plate 1 from sticking together.
〔発明の効果ゴ
以上説明したように、本発明によれば、核燃料要素下部
端栓表面が腐食して下部タイブレート端栓挿入孔と固着
することが殆どないので、長期間使用された核燃料集合
体から核燃料要素を引き抜く作業の際に容易に引き抜く
ことができ、しかも核燃料要素を損傷することがないの
で放射能汚染などの危険を伴うこともない。[Effects of the Invention] As explained above, according to the present invention, the surface of the lower end plug of the nuclear fuel element is hardly corroded and becomes stuck to the lower tie plate end plug insertion hole, so that the nuclear fuel assembly can be used for a long period of time. It can be easily pulled out during work to pull out nuclear fuel elements from a nuclear fuel element, and since the nuclear fuel elements are not damaged, there is no risk of radioactive contamination.
第１図は本発明の一実施例である核燃料集合体における
下部端栓と下部タイプレートとの嵌合部分の縦断面図、
第２図は第１図のＡ−Ａ線に沿う横断面図、第３＠は従
来の核燃料集合体における下部端栓と下部タイプレート
との嵌合部分縦断面図である。
１．１１・・・下部タイプレート、 ２，１２・・・下
部端栓。
２Ａ・・・溝、 ２ａ・・・溝、 ３，１３・・・端栓
挿入孔、４．１４・・・下部端栓テーパ部、
５，１５・・・核燃料要素、
６・・・冷却水流路。FIG. 1 is a longitudinal cross-sectional view of a fitting portion between a lower end plug and a lower tie plate in a nuclear fuel assembly according to an embodiment of the present invention;
FIG. 2 is a cross-sectional view taken along the line A--A in FIG. 1, and FIG. 3 is a vertical cross-sectional view of a portion where a lower end plug and a lower tie plate are fitted in a conventional nuclear fuel assembly. 1.11...Lower tie plate, 2,12...Lower end plug. 2A... Groove, 2a... Groove, 3, 13... End plug insertion hole, 4.14... Lower end plug taper part, 5, 15... Nuclear fuel element, 6... Cooling water flow Road.
Claims (1)
らを支える上部および下部タイプレートとを備えた核燃
料集合体において、下部端栓に複数の溝を設けて下部端
栓と下部タイプレートとの間に冷却水流路を形成したこ
とを特徴とする核燃料集合体。In a nuclear fuel assembly including a plurality of nuclear fuel elements having upper and lower end plugs and upper and lower tie plates supporting these elements, a plurality of grooves are provided in the lower end plug and between the lower end plug and the lower tie plate. A nuclear fuel assembly characterized by having a cooling water flow path formed therein.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2165622A JPH0455793A (en) | 1990-06-26 | 1990-06-26 | Nuclear fuel assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2165622A JPH0455793A (en) | 1990-06-26 | 1990-06-26 | Nuclear fuel assembly |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0455793A true JPH0455793A (en) | 1992-02-24 |
Family
ID=15815862
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2165622A Pending JPH0455793A (en) | 1990-06-26 | 1990-06-26 | Nuclear fuel assembly |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0455793A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2022091260A (en) * | 2020-12-09 | 2022-06-21 | 三菱重工業株式会社 | Lower end plug and fuel rod |
-
1990
- 1990-06-26 JP JP2165622A patent/JPH0455793A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2022091260A (en) * | 2020-12-09 | 2022-06-21 | 三菱重工業株式会社 | Lower end plug and fuel rod |
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