JPS63182599A - Decladding method of spent fuel - Google Patents
Decladding method of spent fuelInfo
- Publication number
- JPS63182599A JPS63182599A JP62015632A JP1563287A JPS63182599A JP S63182599 A JPS63182599 A JP S63182599A JP 62015632 A JP62015632 A JP 62015632A JP 1563287 A JP1563287 A JP 1563287A JP S63182599 A JPS63182599 A JP S63182599A
- Authority
- JP
- Japan
- Prior art keywords
- nuclear fuel
- cladding tube
- rollers
- ductility
- spent
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 12
- 239000002915 spent fuel radioactive waste Substances 0.000 title claims description 10
- 239000003758 nuclear fuel Substances 0.000 claims description 47
- 238000005253 cladding Methods 0.000 claims description 36
- 230000007547 defect Effects 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 238000010008 shearing Methods 0.000 description 3
- 238000007906 compression Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000010309 melting process Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229910001093 Zr alloy Inorganic materials 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000011038 discontinuous diafiltration by volume reduction Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000012958 reprocessing Methods 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
-
- 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
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
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】
（産業上の利用分野）
本発明は、使用済核燃料棒において被覆管内に収容され
た核燃料を取出す方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for extracting nuclear fuel contained in a cladding tube from a spent nuclear fuel rod.
（従来技術）
従来、原子力施設で発生する使用済核燃料を安全に処理
、貯蔵するために種々の提案がなされている。このうち
、核燃料棒については、これを短く切断してステンレス
鋼製の処理槽中で硝酸により溶解させて被覆管とその内
部の燃料とを分離させ、被覆管は圧縮して減容化処理す
るような核燃料の脱被覆方法がとられている。しかし、
このような方法によると、被覆管の内面に付着した燃料
を剥離させるのに長時間を要するばかりでなく、被覆管
の切断片およびその微粉末が処理槽中に混入するため溶
解工程が複雑となり、トラブルの発生原因となり易い欠
点があった。(Prior Art) Various proposals have been made to safely process and store spent nuclear fuel generated at nuclear facilities. Among these, nuclear fuel rods are cut into short lengths and dissolved in nitric acid in a stainless steel treatment tank to separate the cladding from the fuel inside, and the cladding is compressed to reduce its volume. Nuclear fuel stripping methods are being used. but,
According to this method, not only does it take a long time to peel off the fuel adhering to the inner surface of the cladding tube, but the melting process becomes complicated because the cut pieces of the cladding tube and their fine powder get mixed into the treatment tank. However, there were drawbacks that could easily cause problems.
そこで本出願人は、使用済燃料の被覆管を一対の挟み付
けローラにより外周から加圧し、変形させた後、その軸
方向に沿って剪断による切れ目を被覆管の外面から形成
して被覆管を縦割りにし、内部の核燃料を取出す方法を
提案している（特開昭６１−１８８９９号公報参照）。Therefore, the applicant deformed the spent fuel cladding tube by applying pressure from the outer periphery with a pair of pinching rollers, and then formed a shear cut from the outer surface of the cladding tube along the axial direction to deform the cladding tube. They proposed a method of vertically dividing the nuclear fuel and extracting the nuclear fuel inside (see Japanese Patent Application Laid-Open No. 18899/1989).
ところが、この被覆管は中性子照射を受けているため格
子欠陥を生じて硬化しており、延性を失っているため、
ローラを通しても実際にはほとんど変形せず、また軸方
向に剪断を加えた際には、被覆管の材料であるジルカロ
イが発火するおそれがあった。However, since this cladding tube has been exposed to neutron irradiation, it has hardened with lattice defects and has lost its ductility.
Even when it was passed through rollers, it actually hardly deformed, and when shearing was applied in the axial direction, there was a risk that the Zircaloy, the material of the cladding tube, would catch fire.
（発明の目的）
本発明は、上記従来の欠点を解消するためになされたも
のであり、容易にかつ安全に、使用済核燃料棒における
核燃料の脱被覆を行うことができる方法を提供すること
を目的とする。(Object of the Invention) The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a method that can easily and safely declad nuclear fuel in spent nuclear fuel rods. purpose.
（発明の構成）
本発明は、被覆管とその内部に収容された核燃料とから
なる使用済核燃料棒を分解するに際し、この核燃料棒を
少なくとも上記被覆管の延性が回復する温度まで加熱し
、一対のローラからなる挟み付けローラによって移送す
ることにより同核燃料棒を外周から加圧して内部の核燃
料を破壊し、ついでこの破壊された核燃料を被覆管の両
端部から取出すものである。(Structure of the Invention) When disassembling a spent nuclear fuel rod consisting of a cladding tube and nuclear fuel contained therein, the present invention heats the nuclear fuel rod to a temperature at least at which the ductility of the cladding tube is restored, and then The nuclear fuel rod is transferred by a pinching roller consisting of rollers, and the nuclear fuel rod is pressurized from the outer periphery to destroy the nuclear fuel inside, and then the destroyed nuclear fuel is taken out from both ends of the cladding tube.
このような構成によると、加熱によって被覆管の延性か
回復するため、この状態で核燃料棒をローラに通すこと
により被覆管が変形して内部の核燃料が破壊される。こ
のように破壊された核燃料は小片となるため、この状態
で容易に被覆管両端部から取出すことができる。According to such a configuration, the ductility of the cladding tube is restored by heating, and by passing the nuclear fuel rod through the rollers in this state, the cladding tube is deformed and the nuclear fuel inside is destroyed. Since the nuclear fuel destroyed in this way becomes small pieces, it can be easily taken out from both ends of the cladding tube in this state.
（実施例）
第１図において、１は使用済の核燃料集合体であり、多
数本の核燃料棒２とその両端に配置されるフランジ部３
とからなっている。この核燃料集合体１から核燃料棒２
を適宜の手段によって分離し、第２図の右側の図のよう
にする。ここで４は端栓部である。この核燃料棒２は、
第５図および第６図に示されるように、被覆管２１とそ
の内部に収容される核燃料２２とからなっており、被覆
管２１は、中性子照射を受けてその延性が１〜５％まで
低下した状態、すなわち硬化した状態となっている。(Example) In FIG. 1, 1 is a spent nuclear fuel assembly, which includes a large number of nuclear fuel rods 2 and flange portions 3 arranged at both ends thereof.
It consists of From this nuclear fuel assembly 1 to nuclear fuel rod 2
are separated by appropriate means to form the structure shown on the right side of FIG. Here, 4 is an end plug. This nuclear fuel rod 2 is
As shown in FIGS. 5 and 6, it consists of a cladding tube 21 and a nuclear fuel 22 housed inside the cladding tube 21, and the ductility of the cladding tube 21 decreases to 1 to 5% when irradiated with neutrons. In other words, it is in a hardened state.
この核燃料棒２を、第２図に示されるような加熱器５内
に搬送し、高周波によって３０００Ｃ以上に加熱する。This nuclear fuel rod 2 is conveyed into a heater 5 as shown in FIG. 2, and heated to 3000C or more by high frequency.
この工程において、硬化していた被覆管２１はその延性
を１５〜２０％まで取戻し、外力によって十分に変形可
能な状態となる。In this step, the hardened cladding tube 21 regains 15 to 20% of its ductility and becomes fully deformable by external force.
このように加熱された核燃料棒２を、第３〜５図に示さ
れるような挟み付けローラ６によって移送する。挾み付
けローラ６は、側面形状で核燃料棒２の外周面の曲率よ
り小さい曲率のローラ面を有する一対のローラ６１を、
核燃料棒２の長さ方向に対して傾斜しかつ互いに交差す
るように配置してなり、各ローラ６１は、それぞれ軸６
０周りに回転する。このローラ６１間を通過する間に、
核燃料棒２に回転力および軸方向の移送力が付与される
とともに、外周からの圧縮により被覆管２１か変形して
、第６図のように内部の核燃料２２か破壊される。これ
によって、内部の核燃料２２が小片となって被覆管２１
との間に隙間が生じ、この状態で」二足栓４を取外して
被覆管２１の両端部から核燃料２２を取出すことができ
る。核燃料２２を取出した後の被覆管２１は別途減容化
処理する。なお、一般に被覆管から取出した時の核燃料
の形状は問われないので、このように核燃料２２を破壊
して小片にしても不都合は生じない。The nuclear fuel rods 2 heated in this manner are transferred by pinching rollers 6 as shown in FIGS. 3 to 5. The clamping rollers 6 include a pair of rollers 61 having a roller surface with a curvature smaller than the curvature of the outer peripheral surface of the nuclear fuel rod 2 in the side shape.
The rollers 61 are arranged so as to be inclined with respect to the length direction of the nuclear fuel rods 2 and intersect with each other.
Rotates around 0. While passing between these rollers 61,
A rotational force and an axial transfer force are applied to the nuclear fuel rod 2, and the cladding tube 21 is deformed by compression from the outer periphery, and the nuclear fuel 22 inside is destroyed as shown in FIG. As a result, the nuclear fuel 22 inside becomes small pieces and the cladding tube 21
A gap is created between the two ends, and in this state, the two-leg plug 4 can be removed and the nuclear fuel 22 can be taken out from both ends of the cladding tube 21. The cladding tube 21 after the nuclear fuel 22 is removed is subjected to a separate volume reduction treatment. Note that, since the shape of the nuclear fuel when taken out from the cladding tube is generally not critical, there is no problem even if the nuclear fuel 22 is broken into small pieces in this manner.
以上のような方法によれば、一旦被覆管２１を加熱して
変形可能な状態にしてから、ローラ６により圧縮してい
るので、内部の核燃料２２を取出し可能な状態まで破壊
することができ、従来のように発火の危険性のある剪断
作業を行わなくても、容易に被覆管２１と核燃料２２を
完全に分離することができる。これにより、使用済燃料
の再処理を行う際の溶解工程は簡単なものとなり、その
制御も容易となる。According to the method described above, the cladding tube 21 is heated to make it deformable and then compressed by the rollers 6, so that the nuclear fuel 22 inside can be destroyed to a state where it can be taken out. The cladding tube 21 and the nuclear fuel 22 can be easily and completely separated without performing a shearing operation that poses a risk of ignition as in the past. As a result, the melting process when reprocessing spent fuel becomes simple and its control becomes easy.
なお、通常の加工等による硬化は、格子欠陥の中でも転
位（線欠陥）に起因するものであり、延性を十分に回復
させるにはその材料の再結晶温度（ジルカロイ−２の場
合で５５００Ｃ）以上まで加熱しなければならないが、
中性子照射による硬化は、空孔および格子間原子からな
る点欠陥に起因するものであり、転位に比べて欠陥の度
合が少ないため、比較的低温でも延性が回復し易く、上
記のように３０００Ｃまで加熱すれば十分な延性を得ら
れることが確かめられている。従って本発明は、通常の
硬化の場合に比べ、低い温度での加熱で上記効果を得る
ことができる。In addition, hardening due to normal processing is caused by dislocations (line defects) among lattice defects, and in order to sufficiently recover ductility, the temperature must be higher than the recrystallization temperature of the material (5500C in the case of Zircaloy-2). It must be heated to
Hardening caused by neutron irradiation is caused by point defects consisting of vacancies and interstitial atoms, and since the degree of defects is smaller than that of dislocations, ductility is easy to recover even at relatively low temperatures, and as mentioned above, ductility can be recovered up to 3000C. It has been confirmed that sufficient ductility can be obtained by heating. Therefore, in the present invention, the above effects can be obtained by heating at a lower temperature than in the case of normal curing.
また、核燃料棒２を加熱する手段は、」二足のように高
周波を用いるものに限らず、被覆管２１を」１記温度ま
で加熱できるものであればその種類を問わない。Further, the means for heating the nuclear fuel rods 2 is not limited to a method using high frequency waves such as a "bipod", and may be any type as long as it can heat the cladding tube 21 to the temperature listed in "1".
（発明の効果）
以上のように本発明は、延性を失っている被覆管をその
延性か回復するまで一旦加熱し、被覆管か十分に変形可
能な状態となってからローラに通して内部の核燃料を破
壊するようにしているため、従来のような長時間に亘る
溶解処理や発火のおそれのある剪断等を行わずに核燃料
の分解処理を行うことかできる。すなわち、安全かつ容
易に核燃料の脱被覆を行うことができ、処理コストの低
減に寄与することができる。(Effects of the Invention) As described above, the present invention heats a cladding tube that has lost its ductility until the ductility is restored, and after the cladding tube becomes sufficiently deformable, it is passed through rollers and the inside of the cladding tube is heated. Since the nuclear fuel is destroyed, it is possible to disassemble the nuclear fuel without performing a long-time dissolution process or shearing that may cause ignition, as in conventional methods. That is, nuclear fuel can be safely and easily stripped, contributing to a reduction in processing costs.
第１図は本発明の一実施例における核燃料集合体の斜視
図、第２図は同実施例における加熱処理工程を示す斜視
図、第３図は同実施例におけるローラによる圧縮工程を
示す斜視図、第４図は同ローラおよび核燃料棒の平面図
、第５図は第４図の正面図、第６図は同ローラにより核
燃料が破壊された状態を示す正面図である。
２・・・被覆管付核燃料棒、５・・・加熱器、６・・・
挟み付けローラ、２１・・・被覆管、２２・・・核燃料
。FIG. 1 is a perspective view of a nuclear fuel assembly according to an embodiment of the present invention, FIG. 2 is a perspective view showing a heat treatment process in the same embodiment, and FIG. 3 is a perspective view showing a compression process using rollers in the same embodiment. , FIG. 4 is a plan view of the roller and the nuclear fuel rod, FIG. 5 is a front view of FIG. 4, and FIG. 6 is a front view showing the nuclear fuel destroyed by the roller. 2... Nuclear fuel rod with cladding tube, 5... Heater, 6...
Sandwich roller, 21...cladding tube, 22...nuclear fuel.
Claims (1)
用済核燃料棒を分解するに際し、この核燃料棒を少なく
とも上記被覆管の延性が回復する温度まで加熱し、一対
のローラからなる挟み付けローラによって移送すること
により同核燃料棒を外周から加圧して内部の核燃料を破
壊し、ついでこの破壊された核燃料を被覆管の両端部か
ら取出すことを特徴とする使用済燃料の脱被覆方法。1. When disassembling a spent nuclear fuel rod consisting of a cladding tube and the nuclear fuel contained therein, the nuclear fuel rod is heated to at least a temperature at which the ductility of the cladding tube is recovered, and a pinching roller consisting of a pair of rollers is used. A method for decladding spent fuel, which comprises transferring the nuclear fuel rod by pressurizing it from the outer periphery to destroy the nuclear fuel inside, and then taking out the destroyed nuclear fuel from both ends of the cladding tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1563287A JPH0631800B2 (en) | 1987-01-26 | 1987-01-26 | How to de-coat spent fuel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1563287A JPH0631800B2 (en) | 1987-01-26 | 1987-01-26 | How to de-coat spent fuel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63182599A true JPS63182599A (en) | 1988-07-27 |
| JPH0631800B2 JPH0631800B2 (en) | 1994-04-27 |
Family
ID=11894095
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1563287A Expired - Fee Related JPH0631800B2 (en) | 1987-01-26 | 1987-01-26 | How to de-coat spent fuel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0631800B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2938110A1 (en) * | 2008-11-06 | 2010-05-07 | Areva Nc | METHOD FOR EMPTYING NUCLEAR FUEL TANKS AND MILLING MACHINE BY SHEATH DEFORMATION |
| KR20180125064A (en) * | 2017-05-11 | 2018-11-22 | 한전원자력연료 주식회사 | Device for decontaminating fuel cladding for heavy water reactor |
-
1987
- 1987-01-26 JP JP1563287A patent/JPH0631800B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2938110A1 (en) * | 2008-11-06 | 2010-05-07 | Areva Nc | METHOD FOR EMPTYING NUCLEAR FUEL TANKS AND MILLING MACHINE BY SHEATH DEFORMATION |
| WO2010052298A1 (en) * | 2008-11-06 | 2010-05-14 | Areva Nc | Method for emptying nuclear fuel sheaths and sheath-deformation crushing machine |
| US20110204167A1 (en) * | 2008-11-06 | 2011-08-25 | Areva Nc | Method for decladding nuclear fuel and crushing machine by cladding deformation |
| CN102203881A (en) * | 2008-11-06 | 2011-09-28 | 阿雷瓦核废料回收公司 | Method for emptying nuclear fuel sheaths and sheath-deformation crushing machine |
| JP2012507696A (en) * | 2008-11-06 | 2012-03-29 | アレヴァ・エヌセー | Nuclear fuel cladding tube removal method and cladding tube crushing device |
| RU2506658C2 (en) * | 2008-11-06 | 2014-02-10 | Арева Нс | Method of emptying nuclear fuel jackets and machine for grinding nuclear fuel by deforming jackets |
| US8708258B2 (en) * | 2008-11-06 | 2014-04-29 | Areva Nc | Method for decladding nuclear fuel and crushing machine by cladding deformation |
| KR20180125064A (en) * | 2017-05-11 | 2018-11-22 | 한전원자력연료 주식회사 | Device for decontaminating fuel cladding for heavy water reactor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0631800B2 (en) | 1994-04-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |