JPS62291593A - Fuel rod for nuclear reactor - Google Patents
Fuel rod for nuclear reactorInfo
- Publication number
- JPS62291593A JPS62291593A JP61134757A JP13475786A JPS62291593A JP S62291593 A JPS62291593 A JP S62291593A JP 61134757 A JP61134757 A JP 61134757A JP 13475786 A JP13475786 A JP 13475786A JP S62291593 A JPS62291593 A JP S62291593A
- Authority
- JP
- Japan
- Prior art keywords
- fuel rod
- plenum
- end plug
- fuel
- nuclear reactor
- 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 description 43
- 239000008188 pellet Substances 0.000 claims description 28
- 238000005253 cladding Methods 0.000 claims description 18
- OOAWCECZEHPMBX-UHFFFAOYSA-N oxygen(2-);uranium(4+) Chemical compound [O-2].[O-2].[U+4] OOAWCECZEHPMBX-UHFFFAOYSA-N 0.000 claims description 17
- FCTBKIHDJGHPPO-UHFFFAOYSA-N uranium dioxide Inorganic materials O=[U]=O FCTBKIHDJGHPPO-UHFFFAOYSA-N 0.000 claims description 17
- 230000004992 fission Effects 0.000 claims description 16
- 229910001093 Zr alloy Inorganic materials 0.000 claims description 12
- 239000003758 nuclear fuel Substances 0.000 claims description 12
- 239000000843 powder Substances 0.000 claims description 11
- 239000011358 absorbing material Substances 0.000 claims description 7
- 239000007789 gas Substances 0.000 description 23
- 239000001307 helium Substances 0.000 description 7
- 229910052734 helium Inorganic materials 0.000 description 7
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 7
- 238000003780 insertion Methods 0.000 description 6
- 230000037431 insertion Effects 0.000 description 6
- 238000010521 absorption reaction Methods 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000012528 membrane Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-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
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
３、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、原子炉用燃料集合体の燃料棒に係わり、特に
、下部端栓を改良した原子炉用燃料棒に関する。[Detailed Description of the Invention] 3. Detailed Description of the Invention [Object of the Invention] (Field of Industrial Application) The present invention relates to a fuel rod for a fuel assembly for a nuclear reactor, and in particular, to a fuel rod with an improved lower end plug. Regarding fuel rods for nuclear reactors.
（従来の技術）
従来の沸騰水型原子炉における原子炉用燃料棒６は、第
４図に示すようにＳｎ −Ｆｅ −Ｃｒ −Ｎｉ系ジル
コニウム合金で作った被覆管１に二酸化ウランベレット
２．プレナムスプリング３等を装填し、ヘリウムを封入
したのち両端にＳｎ −Ｆｅ −Ｃｒ −Ｎｉ系ジルコ
ニウム合金で第５図ＡおよびＢのように内実状に作った
上および下端枠４および５を溶接した密封構造となって
いる。(Prior Art) As shown in FIG. 4, a reactor fuel rod 6 in a conventional boiling water nuclear reactor has a cladding tube 1 made of a Sn-Fe-Cr-Ni zirconium alloy and a uranium dioxide pellet 2. After loading the plenum spring 3, etc. and filling it with helium, upper and lower end frames 4 and 5 made of Sn-Fe-Cr-Ni zirconium alloy in a solid shape as shown in Fig. 5 A and B were welded to both ends. It has a sealed structure.
被覆管１は、ベレット２を無視しても、運転状態におい
て予想される外圧によって、座屈を起こさないよう十分
な肉厚を有している。二酸化ウランペレット２は、二酸
化ウランベレット粉末を円柱状のベレットに圧縮成形後
焼結して作った高密度のセラミック体であり、両端面に
は面取りを施している。Even if the pellet 2 is ignored, the cladding tube 1 has a sufficient wall thickness so as not to buckle due to the external pressure expected in the operating state. The uranium dioxide pellet 2 is a high-density ceramic body made by compressing uranium dioxide pellet powder into a cylindrical pellet and then sintering it, and both end faces are chamfered.
この二酸化ウランペレット２からは、照射にともない核
分裂生成ガスが放出されるが、それにより燃料棒６の圧
力上昇が過大にならないよう燃料棒６の上部にプレナム
部７が設けられている。このプレナム部７には、プレナ
ムスプリング３が配置され、ウェファ８を介してペレッ
トを下方に押しつけることにより、燃料取扱い時や輸送
時のペレットの移動を防止している。またプレナムスプ
リング３の内側にはステンレス鋼の円筒容器に吸湿材と
してジルコニウム合金の粉末を収納したゲッタ９が挿入
されている。Nuclear fission product gas is released from the uranium dioxide pellets 2 during irradiation, but a plenum portion 7 is provided above the fuel rod 6 to prevent the pressure rise in the fuel rod 6 from becoming excessive due to this. A plenum spring 3 is disposed in the plenum portion 7 and presses the pellets downward via the wafer 8 to prevent the pellets from moving during fuel handling or transportation. Further, inside the plenum spring 3, a getter 9 containing zirconium alloy powder as a moisture absorbing material is inserted in a stainless steel cylindrical container.
（発明が解決しようとする問題点）
ところで、原子炉用燃料棒６が原子炉内で燃焼して行と
、二酸化ウランペレット２からプレナム部７に核分裂生
成ガスが放出される。この核分裂生成ガスは、概して燃
料ペレットの温度に依存することが知られている。(Problems to be Solved by the Invention) By the way, when the reactor fuel rods 6 burn in the reactor, fission product gas is released from the uranium dioxide pellets 2 into the plenum part 7. It is known that this fission gas is generally dependent on the temperature of the fuel pellet.
燃料ペレットの温度上昇に伴い核分裂生成ガスの放出量
も除々に増加する。この時、ヘリウムガスと熱伝達特性
の悪い核分裂生成ガスとが混合することにより、ギャッ
プガスであるヘリウムガスの熱伝達率が低下し、更に燃
料ペレット温度も上昇し、核分裂生成ガスの放出量も増
加し、更にヘリウムガスの熱伝達率も低下するという悪
循環が生じる。As the temperature of the fuel pellet increases, the amount of fission product gas released also increases gradually. At this time, the helium gas and the fission product gas, which have poor heat transfer characteristics, mix, which reduces the heat transfer coefficient of the helium gas, which is the gap gas, and further increases the fuel pellet temperature, causing the amount of fission product gas released to decrease. A vicious cycle occurs in which the heat transfer coefficient of helium gas increases and the heat transfer coefficient of helium gas also decreases.
よって、燃焼が進むにつれて燃料ペレットから放出され
る核分裂生成ガスが増加するので燃料棒内圧もしだいに
上昇する。この核分裂生成−ガスは、原子炉用燃料棒内
に設けられたプレナム部７の二酸化ウランペレット２に
対する割合（プレナム比）を出来る限り大きくすればす
る程、原子炉用燃料棒内に存在する熱伝達特性の良いヘ
リウムガスに対して熱伝達特性の悪い核分裂生成ガスの
占める割合が小さくなるので、ギャップガスの熱伝達率
が改善され、核分裂生成ガスの放出率を低減する事が可
能となる。Therefore, as the combustion progresses, the fission product gas released from the fuel pellets increases, and the internal pressure of the fuel rod gradually increases. The more the ratio (plenum ratio) of the plenum part 7 provided in the reactor fuel rod to the uranium dioxide pellets 2 (plenum ratio) is made as large as possible, the more the nuclear fission generated gas will be absorbed by the heat generated in the reactor fuel rod. Since the ratio of fission product gas, which has poor heat transfer characteristics, to helium gas, which has good transfer characteristics, is smaller, the heat transfer coefficient of the gap gas is improved, and it becomes possible to reduce the release rate of fission product gas.
一方、従来沸騰水型原子炉においては、第４図に示す原
子炉用燃料棒内に設けられるプレナム部７を極端に大き
くする事が構造上及び核特性上不可能である。しかしな
がら、燃料サイクルの経済性の向上等の目的により１国
際的にも近年燃料の高燃焼度化、即ち、燃焼度の伸長に
関心が高まっている。先にも述だ通り、設焼度の伸長に
伴い燃料棒の内圧が上昇するため、この内圧上昇により
燃料棒内圧力（内圧）と冷却材圧力（外圧）との内外圧
力差に基づき被覆管１に生じる応力が増加し、設計限界
応力（許容応力）を越えると燃料棒の建全性に支障が生
じる。On the other hand, in a conventional boiling water reactor, it is impossible due to structural and nuclear characteristics to make the plenum section 7 provided in the reactor fuel rod shown in FIG. 4 extremely large. However, in recent years, there has been increasing interest internationally in increasing the burnup of fuel, that is, increasing the burnup, for the purpose of improving the economic efficiency of the fuel cycle. As mentioned earlier, the internal pressure of the fuel rod increases as the firing temperature increases, and this increase in internal pressure causes the cladding tube to increase due to the pressure difference between the internal and external pressures between the fuel rod internal pressure (internal pressure) and the coolant pressure (external pressure). If the stress generated in 1 increases and exceeds the design limit stress (allowable stress), the integrity of the fuel rod will be impaired.
本発明の目的は、燃焼度を現在よりも伸長させても高い
信頼性が得られる原子炉用燃料棒を提供することにある
。An object of the present invention is to provide a fuel rod for a nuclear reactor that can obtain high reliability even if the burnup is increased from the current level.
（問題点を解決するための手段および作用）本発明の原
子炉用燃料棒は、二酸化ウランペレットを装填した被覆
管の上端および下端を上部端栓及び下部端栓で密封した
原子炉用燃料棒において、上記下部端栓に湿分吸湿材で
あるジルコニウム合金粉末を装填したのち網目状のキャ
ップを覆い被せられる空洞部を設けたことを特徴とする
ものである。(Means and effects for solving the problems) A nuclear reactor fuel rod of the present invention is a nuclear reactor fuel rod in which the upper and lower ends of a cladding tube loaded with uranium dioxide pellets are sealed with an upper end plug and a lower end plug. The lower end plug is characterized by being provided with a cavity portion which is covered with a mesh cap after being filled with zirconium alloy powder, which is a moisture absorbing material.
本発明においては、下部端栓の空洞部に湿分吸湿材であ
るジルコニウム合金粉末を装填したことにより、従来プ
レナム部に設けられていたゲッタを排除することができ
、燃料棒のプレナム比を増大させることができる。In the present invention, by loading zirconium alloy powder, which is a moisture absorbing material, into the cavity of the lower end plug, it is possible to eliminate the getter that was conventionally provided in the plenum part, increasing the plenum ratio of the fuel rod. can be done.
（実施例）
以下、第１図、第２図及び第３図を参照して本発明の一
実施例を説明する。(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1, 2, and 3.
第１図に示した本発明による原子炉用燃料棒６において
も、Ｓｎ −Ｆｅ −Ｃｒ −Ｎｉ系ジルコニウム合金
の被覆管１に二酸化ウランペレット粉末を焼結して円柱
状に形成した複数の二酸化ウランペレット２を積層状に
装填し、この二酸化ウランペレット２が燃料取扱い時や
輸送時に移動しないようにするために、燃料棒上部に設
けられたプレナム部７にプレナムスプリング３を配設し
、このプレナムスプリング３及びウェファ８を介して二
酸化ウランペレット２を押圧固定している。また、被覆
管１の上端には上部端栓４を、下端には下部端栓５をそ
れぞれ溶接して全体を密封しである。Also in the nuclear reactor fuel rod 6 according to the present invention shown in FIG. In order to load uranium pellets 2 in a layered manner and prevent the uranium dioxide pellets 2 from moving during fuel handling or transportation, a plenum spring 3 is provided in the plenum section 7 provided at the top of the fuel rod. A uranium dioxide pellet 2 is pressed and fixed via a plenum spring 3 and a wafer 8. Further, an upper end plug 4 is welded to the upper end of the cladding tube 1, and a lower end plug 5 is welded to the lower end to seal the entire cladding tube.
しかして、本発明においては、被覆管１の上端および下
端を密封する上部端栓４および下部端栓５に改良を加え
たものである。本発明に使用する上部端栓４および下部
端栓５は、第２図Ａおよび已に示すように、上部あるい
は下部タイブレート（図示省略）に支持されるシャンク
４ａ、 ５ａと、被覆管１内に挿入されて被覆管１と上
部及び下部端栓４，５間の組立時の偏心や傾きを防止す
るための挿入部４ｂ、 ５ｂと、シャンク４ａ、 ５ａ
及び挿入部４ｂ。Therefore, in the present invention, improvements have been made to the upper end plug 4 and lower end plug 5 that seal the upper and lower ends of the cladding tube 1. The upper end plug 4 and the lower end plug 5 used in the present invention, as shown in FIG. Insertion parts 4b and 5b are inserted to prevent eccentricity and inclination during assembly between the cladding tube 1 and the upper and lower end plugs 4 and 5, and shanks 4a and 5a.
and insertion section 4b.
５ｂを一体に連結しているバレル部４ｃ、 ５ｃからな
っている。このバレル部４ｃ、 ５ｃの外径は、組立性
等を考慮して被覆管１の外径と等しくしている。It consists of barrel parts 4c and 5c which integrally connect the barrel parts 5b. The outer diameter of the barrel portions 4c, 5c is made equal to the outer diameter of the cladding tube 1 in consideration of ease of assembly.
本発明の上部、下部端栓４，５は挿入部４ｂ、 ５ｂの
上端面からバレル部４ｃ、 ５ｃにわたって、盲穴の空
洞部４ｄ、 ５ｄを上部及び下部端栓の軸心に沿って設
けられている。この上部端栓４に設けた空洞部４ｄは、
核分裂生成ガス等を蓄めるために設けたものであり、ま
た、下部端栓５に設けた空洞部５ｄは、湿分吸湿材であ
るジルコニウム合金粉末１０を装填するためのものであ
る。The upper and lower end plugs 4 and 5 of the present invention have blind hole cavities 4d and 5d extending from the upper end surface of the insertion portions 4b and 5b to the barrel portions 4c and 5c along the axes of the upper and lower end plugs. ing. The cavity 4d provided in the upper end plug 4 is
It is provided to store nuclear fission product gas and the like, and the cavity 5d provided in the lower end plug 5 is used to load zirconium alloy powder 10, which is a moisture absorbing material.
この盲穴の空洞部４ｄ、５ｄを設けるに当り、上部及び
下部端栓４，５の肉厚ｔａｙ ｉｂは、被覆管１と同等
若しくはそれ以上の機械的強度を有する様に被覆管１の
肉厚ｔｃと同等若しくはそれ以上としている。これは、
原子炉運転中に原子炉用燃料棒６には、燃焼の進行に伴
い二酸化ウランペレット２から放出される核分裂生成ガ
スにより燃料棒６の内圧は除々に上昇して行くため、こ
の内圧上昇により燃料棒内圧力（内圧）と冷却材圧力（
外圧）との内外圧力差に基づいて生じる応力が設計限界
応力（許容応力）を超えない様決定したものである。
この内外圧力差に基づいて生じる応力は、大別して膜応
力と曲げ応力に分類されるが、膜応カク、は、肉厚ｔに
対して平均的にかかる応力であり。In providing the blind hole cavities 4d and 5d, the wall thickness tayib of the upper and lower end plugs 4 and 5 is adjusted so that the wall thickness of the cladding tube 1 is equal to or greater than that of the cladding tube 1. The thickness is equal to or greater than the thickness tc. this is,
During reactor operation, the internal pressure of the fuel rod 6 gradually increases due to the fission product gas released from the uranium dioxide pellets 2 as combustion progresses, so this increase in internal pressure causes the fuel Pressure inside the rod (internal pressure) and coolant pressure (
This was determined so that the stress generated based on the difference between the internal and external pressures (external pressure) does not exceed the design limit stress (allowable stress).
The stress generated based on this internal and external pressure difference is broadly classified into membrane stress and bending stress, and the membrane stress is the stress applied on average to the wall thickness t.
曲げ応力びゎは、 肉厚ｔに対して分布をもつ応力であ
り。Bending stress is a stress that has a distribution with respect to wall thickness t.
１７ｂ″ ］「 ２；断面係数と表わさ
れるので、肉厚対半径比（Ｆ−）及び断面係数（Ｚ）を
被覆管２と比較して同等若しくはそれ以上にする事によ
り、上部及び下部端栓に生じる応力が被覆管に発生する
応力により小さくなり、上部及び下部端栓４，５が機械
的に健全であることが保証される。17b" ] "2; It is expressed as the section modulus, so by making the wall thickness to radius ratio (F-) and section modulus (Z) equal to or higher than that of the cladding tube 2, the upper and lower end plugs can be The stresses occurring in the cladding are reduced by the stresses occurring in the cladding, ensuring that the upper and lower end plugs 4, 5 are mechanically sound.
また、燃料棒６の内圧は、原子炉用燃料棒製作時に封入
するヘリウムガスと二酸化ウランペレット２の揮発性不
純物並びに二酸化ウランペレット２より放出される核分
裂生成ガスにより生じる。Further, the internal pressure of the fuel rod 6 is caused by helium gas sealed during the fabrication of the fuel rod for a nuclear reactor, volatile impurities in the uranium dioxide pellets 2, and fission product gas released from the uranium dioxide pellets 2.
燃料棒６の上部に設けられているプレナム部７は先にも
述べた様に二酸化ウランペレット２から放出される核分
裂生成ガス等を蓄えるために設けたものであり、このプ
レナム部７の体積は、核分裂生成ガス等による圧力上昇
により破損が発生する事がなうよう決められている６し
かし、燃料の高燃焼度化即ち燃焼度の伸長に対応して出
来る限りプレナム比（プレナム体積／ペレットスタック
体積）を大きくする事が望ましい。As mentioned earlier, the plenum part 7 provided at the top of the fuel rod 6 is provided to store the fission product gas etc. released from the uranium dioxide pellets 2, and the volume of this plenum part 7 is The plenum ratio (plenum volume/pellet stack It is desirable to increase the volume.
プレナム体積■２は、下式により表わされる。The plenum volume ■2 is expressed by the following formula.
プレナム部空間体積は、プレナム部７の正味空間体積を
指す。The plenum spatial volume refers to the net spatial volume of the plenum 7.
また、プレナム部部品体積Ｖ、は、プレナム部に設けら
れているプレナムスプリング３、ウェファ８及びゲッタ
９から成る各部品体積の総和である。Further, the plenum part component volume V is the sum total of the volumes of each component including the plenum spring 3, wafer 8, and getter 9 provided in the plenum part.
本発明は、上記ゲッタ９をプレナム部７からの排除、且
つ、上部端栓４に空洞部４ｄを設けることによりプレナ
ム体積ＶＰの増加をはかったのが一つの特徴であって、
ここで、本発明によるプレナム体積をｖＰ、従来のプレ
ナム体積をｖＰ′及びペレットスタック体積をＶＦとす
ると、本発明によるプレナム比ｆ ＝ ｌ／Ｐ／ＶＦと
従来のプレナム比ｆ’＝ｖＰ′／■Ｆ間に以下に示す関
係が成り立つ。One of the features of the present invention is that the plenum volume VP is increased by removing the getter 9 from the plenum part 7 and providing a hollow part 4d in the upper end plug 4,
Here, if the plenum volume according to the present invention is vP, the conventional plenum volume is vP', and the pellet stack volume is VF, then the plenum ratio according to the present invention f = l/P/VF and the conventional plenum ratio f' = vP'/ ■The relationship shown below holds between F.
また、従来プレナム部７においては、先にも述べた様に
、燃料棒内に残存する水分（水崇）を吸収する目的によ
り、湿分吸収能力を有する湿分吸湿材のジルコニウム合
金粉末１０をステンレス鋼の円筒容器に収納したゲッタ
９を設けていた。In addition, in the conventional plenum section 7, as mentioned earlier, zirconium alloy powder 10, which is a moisture absorbing material having moisture absorption ability, is used for the purpose of absorbing the moisture remaining in the fuel rods. A getter 9 housed in a stainless steel cylindrical container was provided.
ところが、燃料の高燃焼度化、即ち、燃焼度の伸長に対
応してプレナム比の増大をはかる目的により、先に述べ
た様に、プレナム部７からゲッタ９の排除等により、従
来よりプレナム比の増大をはかった。しかし、燃料棒内
に残存する水分（水素）による燃料棒６（被覆管１）の
局所水素化につながる可能性があるため、燃料性能上ゲ
ッタ９を燃料棒内から徘飲する事は、好ましく無い。However, for the purpose of increasing the plenum ratio in response to increasing the burnup of the fuel, that is, increasing the burnup, as mentioned above, the plenum ratio has been increased by removing the getter 9 from the plenum part 7. We aimed to increase the number of people. However, in terms of fuel performance, it is preferable not to drink the getter 9 from inside the fuel rod, as it may lead to local hydrogenation of the fuel rod 6 (cladding tube 1) due to moisture (hydrogen) remaining inside the fuel rod. None.
そこで、本発明においては第２図に示す様に下部端栓５
に設けた空洞部５ｄに湿分吸湿材のジルコニウム合金粉
末１０を装填して、従来と同等の燃料性能を保証してい
る。また第３図に示すように下部端栓５の挿入部５ｂ側
壁面には、径方向の放射状に切欠された複数のＵ牢死５
ｅが設けられている。Therefore, in the present invention, as shown in FIG.
Zirconium alloy powder 10, which is a moisture absorbing material, is loaded into the cavity 5d provided in the fuel cell to ensure fuel performance equivalent to that of the conventional fuel. Further, as shown in FIG. 3, on the side wall surface of the insertion portion 5b of the lower end plug 5, there are a plurality of U holes 5 cut out radially in the radial direction.
e is provided.
さらに燃料ｍ６の組立時において、前記下部端栓５の空
洞部５ｄにジルコニウム合金粉末１ｏを装填した後、第
３図に示すキャップ１１を前記下部端栓５の挿入部５ｂ
に覆い被せ、下部端栓５に固着させる。Furthermore, when assembling the fuel m6, after loading the zirconium alloy powder 1o into the cavity 5d of the lower end plug 5, the cap 11 shown in FIG.
and fix it to the lower end plug 5.
このキャップ１１は、網目状に成っているため、燃料棒
組立後においても二酸化ウランペレット２及び燃料棒６
中に残在する水分（水素）を下部端栓５の挿入部５ｂに
設けられたＵ室孔より水分（水素）を吸収することがで
きる。Since this cap 11 has a mesh shape, the uranium dioxide pellets 2 and the fuel rods 6 can be removed even after the fuel rods are assembled.
The moisture (hydrogen) remaining inside can be absorbed through the U-chamber hole provided in the insertion portion 5b of the lower end plug 5.
以上のように本発明によれば、二酸化ウランペレットを
装填した被覆管の上下両端を上部端栓及び下部端栓で密
封した原子炉用燃料棒において、その上部端栓及び下部
端栓に空洞部を設け、その上部端栓の空洞部を核分裂生
成ガス等の蓄えるのに利用し、下部端栓の空洞部に湿分
吸湿材であるジルコニウム合金粉末を装填して網目状の
キャップを覆い被せた事により、従来プレナム部に設け
られていたゲッタを排除することができ、このゲッタを
排除した事により従来の原子炉用燃料棒と比較して約１
０％プレナム比を増大する事が出来た。As described above, according to the present invention, in a nuclear reactor fuel rod in which both the upper and lower ends of a cladding tube loaded with uranium dioxide pellets are sealed with an upper end plug and a lower end plug, a cavity is formed in the upper end plug and the lower end plug. The cavity of the upper end plug was used to store fission product gas, etc., and the cavity of the lower end plug was filled with zirconium alloy powder, which is a moisture absorption material, and covered with a mesh cap. As a result, the getter that was conventionally installed in the plenum can be eliminated, and by eliminating this getter, the fuel rod size is approximately 1
It was possible to increase the plenum ratio by 0%.
第１図は本発明に係る原子炉用燃料棒の一実施例を示す
概略縦断面図、第２図ＡおよびＢは第１図に示す上部及
び下部端栓を拡大して示す縦断面図、第３図は第１図で
示す下部端栓とキャップの分解斜視図、第４図は従来の
原子炉用燃料棒を示す概略縦断面図、第５図は第４図に
示す上部及び下部端栓を拡大して示す縦断面図である。
１・・・被覆管 ２・・・二酸化ウランペ
レット３・・・プレナムスプリング ４・・・上部端栓
５・・・下部端栓 ４ａ、５ａ・・・シャン
ク部４ｂ、 ５ｂ・・・挿入部 ４ｃ、 ５ｃ
・・・バレル部４ｄ、５ｄ・・・空洞部 ５ｅ
・・・Ｕ室孔６・・・燃料棒 ７・・・プ
レナム部８・・・ウェファ ９・・・ゲッタ
１０・・・湿分吸湿材ジルコニウム合金粉末１１・・・
キャップ
（８７３３）代理人弁理士 猪 股 祥 晃（はが１名
）＄ ２ ：’
第 ４ 図
第 ５ ｇFIG. 1 is a schematic vertical cross-sectional view showing an embodiment of a nuclear reactor fuel rod according to the present invention, FIGS. 2 A and B are longitudinal cross-sectional views showing enlarged upper and lower end plugs shown in FIG. 1, Fig. 3 is an exploded perspective view of the lower end plug and cap shown in Fig. 1, Fig. 4 is a schematic vertical sectional view showing a conventional nuclear reactor fuel rod, and Fig. 5 is the upper and lower ends shown in Fig. 4. It is a longitudinal cross-sectional view which expands and shows a stopper. 1... Cladding tube 2... Uranium dioxide pellet 3... Plenum spring 4... Upper end plug 5... Lower end plug 4a, 5a... Shank part 4b, 5b... Insertion part 4c , 5c
...Barrel parts 4d, 5d...Cavity part 5e
... U chamber hole 6 ... Fuel rod 7 ... Plenum part 8 ... Wafer 9 ... Getter 10 ... Moisture absorption material zirconium alloy powder 11 ...
Cap (8733) Representative Patent Attorney Yoshiaki Inomata (1 person) $2:' Figure 4 Figure 5 g
Claims (1)
よび下端を上部端栓及び下部端栓で密封した原子炉用燃
料棒において、上記下部端栓に湿分吸湿材であるジルコ
ニウム合金粉末を装填したのち網目状のキャップを覆い
被せられる空洞部を設けたことを特徴とする原子炉用燃
料棒。 ２ 上部端栓に核分裂生成ガスなどを蓄えられる空洞部
を設けたことを特徴とする特許請求の範囲第１項記載の
原子炉用燃料棒。(1) In a nuclear reactor fuel rod in which the upper and lower ends of a cladding tube loaded with uranium dioxide pellets are sealed with an upper end plug and a lower end plug, the lower end plug is loaded with zirconium alloy powder, which is a moisture absorbing material. A fuel rod for a nuclear reactor characterized by having a hollow portion that can be later covered with a mesh-like cap. 2. The fuel rod for a nuclear reactor according to claim 1, characterized in that the upper end plug is provided with a cavity in which fission product gas, etc. can be stored.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61134757A JPS62291593A (en) | 1986-06-12 | 1986-06-12 | Fuel rod for nuclear reactor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61134757A JPS62291593A (en) | 1986-06-12 | 1986-06-12 | Fuel rod for nuclear reactor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62291593A true JPS62291593A (en) | 1987-12-18 |
Family
ID=15135848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61134757A Pending JPS62291593A (en) | 1986-06-12 | 1986-06-12 | Fuel rod for nuclear reactor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62291593A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023122358A3 (en) * | 2021-06-21 | 2023-08-10 | Westinghouse Electric Company Llc | Methods and devices to improve performances of rcca and cea to mitigate clad strain in the high fluence region |
-
1986
- 1986-06-12 JP JP61134757A patent/JPS62291593A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023122358A3 (en) * | 2021-06-21 | 2023-08-10 | Westinghouse Electric Company Llc | Methods and devices to improve performances of rcca and cea to mitigate clad strain in the high fluence region |
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