JPH09178890A - Crushing method for nuclear fuel powder - Google Patents

Crushing method for nuclear fuel powder

Info

Publication number
JPH09178890A
JPH09178890A JP7340285A JP34028595A JPH09178890A JP H09178890 A JPH09178890 A JP H09178890A JP 7340285 A JP7340285 A JP 7340285A JP 34028595 A JP34028595 A JP 34028595A JP H09178890 A JPH09178890 A JP H09178890A
Authority
JP
Japan
Prior art keywords
powder
nuclear fuel
inert gas
pot
mill pot
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
Application number
JP7340285A
Other languages
Japanese (ja)
Inventor
Shinichi Hasegawa
伸一 長谷川
Haruo Tsuchiya
晴雄 土屋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Materials Corp
Original Assignee
Mitsubishi Materials Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Materials Corp filed Critical Mitsubishi Materials Corp
Priority to JP7340285A priority Critical patent/JPH09178890A/en
Publication of JPH09178890A publication Critical patent/JPH09178890A/en
Pending legal-status Critical Current

Links

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00Energy generation of nuclear origin
    • Y02E30/30Nuclear fission reactors

Landscapes

  • Crushing And Pulverization Processes (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)

Abstract

PROBLEM TO BE SOLVED: To continuously crush UO2 powder for an uranium oxide fuel, continuously crush and mix PuO2 powder and UO2 powder for an uranium-plutonium mixed oxide fuel (MOX fuel), an improve the processing capability and work efficiency. SOLUTION: A mill pot 21 having the diameter that nuclear fuel powders 11, 12 are kept subcritical is arranged around the axial direction of a main spindle 18, and the mill pot 21 is rotated and revolved around the main spindle 18 while a crushing medium 21e is stored in it. The powder 11, containing a coagulated powder is fed to the feed section 23 of the mill pot 21, and simultaneously an inert gas is fed to the section 23. The powder 11 fed into the mill pot 21 from the feed section 23 and containing the coagulated powder is crushed by the crushing medium 21e via the centrifugal force generated by the rotation and revolution of the mill pot 21 in the inert gas atmosphere. The crushed powder 12 is recovered in a recovery container having the shape that the powder 12 is kept subcritical by the inert gas.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【発明の属する技術分野】本発明は、ウラン酸化物燃料
やウラン・プルトニウム混合酸化物燃料を製造する方法
に関する。更に詳しくは、UO2粉末を均一に粉砕した
り、或いはPuO2粉末とUO2粉末を均一に粉砕・混合
する方法に関するものである。
TECHNICAL FIELD The present invention relates to a method for producing a uranium oxide fuel or a uranium / plutonium mixed oxide fuel. More particularly, the invention relates to a method or uniformly pulverized UO 2 powder, or PuO homogeneously pulverized and mixed with 2 powder and UO 2 powder.

【0002】[0002]

【従来の技術】ウラン・プルトニウム混合酸化物燃料
(以下、MOX燃料という)はペレット製造工程におけ
るプルトニウムスポットの発生を防止するためにPuO
2粉末とUO2粉末をその混合工程で均一に混合する必要
があった。そのため従来PuO2粉末とUO2粉末との混
合はボールミルにより粉砕・混合する方法が採用されて
いる。
2. Description of the Related Art Uranium-plutonium mixed oxide fuel (hereinafter referred to as MOX fuel) is PuO in order to prevent generation of plutonium spots in the pellet manufacturing process.
It was necessary to uniformly mix the 2 powder and the UO 2 powder in the mixing process. Therefore, conventionally, the method of mixing the PuO 2 powder and the UO 2 powder has been adopted by pulverizing and mixing with a ball mill.

【0003】[0003]

【発明が解決しようとする課題】しかし、上記従来のボ
ールミルによる粉砕・混合では、バッチ操作であるため
蓋の開閉操作が必要となり、またグローブボックス内で
の操作であるため作業効率は良くなく、更に粉末の投入
と排出は自動化が容易でない等の不具合があった。この
結果、蓋の開閉時にUO2粉末及びPuO2粉末が散逸す
る問題点もあった。また、上記従来のボールミルによる
粉砕・混合では、臨界安全管理をする必要から、1バッ
チあたりの取扱量が決められ、一度に多量に粉砕・混合
することができず、また8〜16時間程度の比較的長時
間を要し、処理能力を大きくするにはボールミルの台数
を増加させる必要があった。また、上記従来のボールミ
ルによる粉砕・混合では、上記のように処理時間が比較
的長いため、不活性ガス雰囲気中でUO2粉末及びPu
2粉末を粉砕・混合しても、外部から空気が流入して
上記粉末が酸化される恐れがあった。更に、上記従来の
ボールミルによる粉砕・混合では、処理時間が比較的長
いため、ボールミルの粉砕媒体が粉砕・混合中に摩耗し
て、この摩耗粉が粉砕・混合後のUO2粉末及びPuO2
粉末に不純物として混入する量が比較的多い問題点があ
った。
However, in the above-mentioned conventional pulverization / mixing by the ball mill, the opening / closing operation of the lid is required because it is a batch operation, and the operation efficiency is not good because it is an operation in the glove box. Further, there is a problem that it is not easy to automate the loading and discharging of the powder. As a result, there is also a problem that UO 2 powder and PuO 2 powder are scattered when the lid is opened and closed. In the conventional pulverization / mixing by the ball mill, the handling amount per batch is determined because it is necessary to perform criticality safety control, and it is impossible to pulverize / mix a large amount at one time, and it takes about 8 to 16 hours. It took a relatively long time, and it was necessary to increase the number of ball mills in order to increase the processing capacity. Further, in the conventional pulverization / mixing by the ball mill, since the processing time is relatively long as described above, UO 2 powder and Pu are processed in the inert gas atmosphere.
Even if the O 2 powder was crushed and mixed, there was a risk that air would flow in from the outside and the powder would be oxidized. Further, in the conventional pulverization / mixing by the ball mill, since the processing time is relatively long, the pulverization medium of the ball mill is worn during the pulverization / mixing, and the abrasion powder is crushed / mixed by the UO 2 powder and PuO 2 powder.
There is a problem that the amount of impurities mixed in the powder is relatively large.

【0004】本発明の目的は、ウラン酸化物燃料にあっ
ては連続的にUO2粉末を粉砕でき、MOX燃料にあっ
ては連続的にPuO2粉末及びUO2粉末を粉砕・混合で
き、処理能力及び作業能率を向上できる核燃料粉末の粉
砕方法を提供することにある。本発明の別の目的は、粉
砕媒体の摩耗粉が粉砕後の核燃料粉末に混入する量が極
めて僅かで済み、核燃料粉末の散逸及び酸化を防止でき
る核燃料粉末の粉砕方法を提供することにある。本発明
の更に別の目的は、臨界安全管理を容易に行うことがで
き、かつ粉砕又は粉砕・混合の均一性がよい核燃料粉末
の粉砕方法を提供することにある。
The object of the present invention is to continuously grind UO 2 powder in the case of uranium oxide fuel and continuously grind and mix PuO 2 powder and UO 2 powder in the case of MOX fuel. An object of the present invention is to provide a method for pulverizing nuclear fuel powder that can improve the capacity and work efficiency. Another object of the present invention is to provide a method for pulverizing nuclear fuel powder in which abrasion powder of a pulverizing medium is mixed in the nuclear fuel powder after pulverization in an extremely small amount, and dissipation and oxidation of the nuclear fuel powder can be prevented. Still another object of the present invention is to provide a pulverization method of nuclear fuel powder which can easily perform criticality safety control and has good pulverization or pulverization / mixing uniformity.

【0005】[0005]

【課題を解決するための手段】請求項1に係る発明は、
図1に示すように主軸18の軸方向周囲に配設されポッ
ト21内に粉砕媒体21eを収容しかつ核燃料粉末1
1,12が臨界にならない直径を有する複数のミルポッ
ト21を自転させながら主軸18回りに公転させる工程
と、凝集粉を含む核燃料粉末11をミルポット21の供
給部23に搬送する工程と、上記供給部23に不活性ガ
スを供給する工程と、供給部23から粉末11をミルポ
ット21内に供給し不活性ガス雰囲気下で自転と公転に
より生じる遠心力で粉砕媒体21eにより凝集粉を含む
粉末11を粉砕する工程と、粉砕した粉末12を不活性
ガスにより粉末12が臨界にならない形状の回収容器1
4に回収する工程とを含む核燃料粉末の粉砕方法であ
る。この核燃料粉末の粉砕方法では、凝集粉を含む核燃
料粉末11が順次ミルポット21に供給され、このミル
ポット21で粉砕された粉末12は不活性ガスにより回
収容器14に回収されるので、連続的に効率よく粉末1
1を粉砕できる。また粉末11が粉砕媒体21eと接触
する時間が比較的短いため、粉砕媒体21eの摩耗粉が
粉砕した粉末12に混入する量が極めて僅かで済む。
The invention according to claim 1 is
As shown in FIG. 1, a crushing medium 21e is accommodated in a pot 21 arranged around the main shaft 18 in the axial direction and the nuclear fuel powder 1
A step of revolving a plurality of mill pots 21 having diameters where 1 and 12 are not critical while revolving around the spindle 18, a step of transporting nuclear fuel powder 11 containing agglomerated powder to a feed portion 23 of the mill pot 21, and the above feed portion The step of supplying the inert gas to 23 and the step of supplying the powder 11 from the supply part 23 into the mill pot 21 and crushing the powder 11 containing the agglomerated powder by the grinding medium 21e by the centrifugal force generated by the rotation and the revolution in the inert gas atmosphere. And the recovery container 1 having a shape in which the powder 12 is not critical due to the inert gas.
And a step of recovering the nuclear fuel powder. In this method for pulverizing nuclear fuel powder, the nuclear fuel powder 11 containing agglomerated powder is sequentially supplied to the mill pot 21, and the powder 12 pulverized by the mill pot 21 is recovered in the recovery container 14 by the inert gas. Well powder 1
1 can be crushed. Further, since the time during which the powder 11 is in contact with the grinding medium 21e is relatively short, the amount of the abrasion powder of the grinding medium 21e mixed into the ground powder 12 is extremely small.

【0006】請求項2に係る発明は、請求項1に係る発
明であって、図4に示すように粉砕した核燃料粉末12
を回収容器14に搬送する不活性ガスが供給部23に供
給され、不活性ガスの全流路が閉ループを構成する核燃
料粉末の粉砕方法である。この核燃料粉末の粉砕方法で
は、粉砕した核燃料粉末11を回収容器14に搬送した
不活性ガスを循環させて何度も使用するため、比較的少
量の不活性ガスで済む。請求項3に係る発明は、請求項
1又は2に係る発明であって、凝集粉を含む粉末の供給
量及び不活性ガスの供給量のいずれか一方又は双方を調
整可能にした核燃料粉末の粉砕方法である。この核燃料
粉末の粉砕方法では、粉砕した核燃料粉末を更に均一に
することができる。
The invention according to claim 2 is the invention according to claim 1, which is a nuclear fuel powder 12 crushed as shown in FIG.
Is a method for pulverizing nuclear fuel powder in which an inert gas that conveys to the recovery container 14 is supplied to the supply unit 23 and all the flow paths of the inert gas form a closed loop. In this method for pulverizing nuclear fuel powder, the pulverized nuclear fuel powder 11 is circulated in the inert gas conveyed to the recovery container 14 and used many times, so a relatively small amount of inert gas is required. The invention according to claim 3 is the invention according to claim 1 or 2, wherein one or both of the supply amount of the powder containing the aggregated powder and the supply amount of the inert gas can be adjusted, and the nuclear fuel powder is pulverized. Is the way. According to this pulverization method of nuclear fuel powder, the pulverized nuclear fuel powder can be made more uniform.

【0007】[0007]

【発明の実施の形態】次に本発明の実施の形態を図面に
基づいて詳しく説明する。図1〜図4に示すように、凝
集粉を含むウラン・プルトニウム混合酸化物粉末11を
粉砕・混合し回収する装置は、上記粉末11を粉砕・混
合するボールミル13と、このボールミル13により粉
砕・混合した粉末12をサイクロン分離器28を介して
回収する回収容器14と、粉砕・混合した粉末12をボ
ールミル13から回収容器14に搬送する処理後粉末搬
送手段16とを備える。なお、核燃料粉末としてウラン
・プルトニウム混合酸化物粉末を挙げたが、これに限ら
ずウラン酸化物粉末或いはペレットの解砕粉末でもよ
い。
Embodiments of the present invention will now be described in detail with reference to the drawings. As shown in FIGS. 1 to 4, the apparatus for crushing and mixing the uranium-plutonium mixed oxide powder 11 containing agglomerated powder is a ball mill 13 for crushing and mixing the powder 11, and a ball mill 13 for crushing and mixing. A collection container 14 for collecting the mixed powder 12 via a cyclone separator 28, and a post-treatment powder carrying means 16 for carrying the crushed and mixed powder 12 from the ball mill 13 to the collection container 14. Although the uranium-plutonium mixed oxide powder was mentioned as the nuclear fuel powder, the nuclear fuel powder is not limited to this and may be uranium oxide powder or crushed powder of pellets.

【0008】ボールミル13は図1に詳しく示すよう
に、ベース17に立設された主軸18と、この主軸18
に回転可能に嵌入され軸方向周囲に複数のポット収容部
19aが形成されたポットホルダ19と、このポットホ
ルダ19に回転可能に収容されたミルポット21とを有
する。主軸18の下端はベース17上に固定され、主軸
18の上端には太陽歯車18aが嵌着される。ポットホ
ルダ19は主軸18に2つのラジアル軸受19b,19
b及び1つのスラスト軸受19cを介して回転可能に嵌
入され、ポットホルダ19の下端には従動歯車19dが
このホルダ19と一体的に形成される。従動歯車19d
は電動モータ22の出力軸22aに嵌着された駆動歯車
22bに噛合する。またポット収容部19aは主軸18
を中心とする同一円周上に等間隔に複数設けられる。こ
の実施の形態ではポット収容部19aは4つである。
As shown in detail in FIG. 1, the ball mill 13 has a main shaft 18 erected on a base 17 and a main shaft 18.
The pot holder 19 has a plurality of pot accommodating portions 19a formed therein so as to be rotatably fitted therein, and a mill pot 21 rotatably accommodated in the pot holder 19. The lower end of the main shaft 18 is fixed on the base 17, and the sun gear 18a is fitted on the upper end of the main shaft 18. The pot holder 19 has two radial bearings 19 b, 19 on the main shaft 18.
It is rotatably fitted through b and one thrust bearing 19c, and a driven gear 19d is integrally formed with the holder 19 at the lower end of the pot holder 19. Driven gear 19d
Meshes with the drive gear 22b fitted to the output shaft 22a of the electric motor 22. Further, the pot accommodating portion 19a is the main shaft 18
Are provided at equal intervals on the same circumference centered on. In this embodiment, there are four pot housing portions 19a.

【0009】ミルポット21は上記ポット収容部19a
に2つのラジアル軸受21a,21aを介して回転可能
にそれぞれ収容される。ミルポット21の直径は凝集粉
を含む粉末11及び粉砕・混合した粉末12が臨界にな
らない直径に形成される。ポット収容部19aの底部に
は通孔19eが形成され、ミルポット21の底部には上
記通孔19eと略同一の孔径を有する透孔21bが形成
される。またミルポット21をポット収容部19aに収
容した状態で、ポット収容部19aの底部上面とミルポ
ット21の底部下面との間には第1摩擦低減部材31が
介装される(図1及び図3)。ミルポット21の上端に
は開口部21cが形成され、ミルポット21の上部外周
面にはこのポット21と一体的に遊星歯車21dが設け
られ、遊星歯車21dは上記太陽歯車18aと噛合す
る。また21eはミルポット21に収容された所定の直
径を有するジルコニア製の多数のセラミックボールであ
り、21fは透孔21bを塞ぐ所定のメッシュの網であ
る(図1)。この網21fのメッシュは凝集粉を含む粉
末11を通過不能にかつ粉砕・混合した粉末12を通過
可能に形成される。なお、ポット収容部及びミルポット
は4つではなく、2つ、3つ又は5つ以上でもよい。ま
た、ミルポットに収容される多数のボールはジルコニア
に限らず、アルミナ、タングステンカーバイト等により
形成してもよい。
The mill pot 21 is the pot accommodating portion 19a.
Are rotatably housed via two radial bearings 21a, 21a, respectively. The diameter of the mill pot 21 is formed so that the powder 11 containing agglomerated powder and the powder 12 crushed and mixed do not become critical. A through hole 19e is formed at the bottom of the pot housing portion 19a, and a through hole 21b having a hole diameter substantially the same as the through hole 19e is formed at the bottom of the mill pot 21. Further, with the mill pot 21 accommodated in the pot accommodating portion 19a, a first friction reducing member 31 is interposed between the bottom upper surface of the pot accommodating portion 19a and the bottom lower surface of the mill pot 21 (FIGS. 1 and 3). . An opening 21c is formed at the upper end of the mill pot 21, and a planetary gear 21d is integrally provided with the pot 21 on the outer peripheral surface of the upper portion of the mill pot 21, and the planetary gear 21d meshes with the sun gear 18a. Further, 21e is a large number of zirconia ceramic balls having a predetermined diameter housed in the mill pot 21, and 21f is a predetermined mesh net that closes the through holes 21b (FIG. 1). The mesh of the net 21f is formed so that the powder 11 containing the agglomerated powder cannot pass through and the powder 12 crushed and mixed can pass through. Note that the number of pot housings and mill pots may be two, three, or five or more instead of four. Further, the many balls accommodated in the mill pot are not limited to zirconia, but may be formed of alumina, tungsten carbide or the like.

【0010】ミルポット21の上端には略円錐状の供給
ケース23が設けられる(図1及び図4)。供給ケース
23の上端には供給口23aが形成され、下端にはミル
ポット21の開口部21cに第2摩擦低減部材32(図
1及び図3)を介して挿入可能な排出口23bがそれぞ
れ形成される(図1)。供給ケース23の供給口23a
には粉末下流側管路24及び処理前粉末搬送手段25を
介してホッパ26が接続される(図4)。このホッパ2
6には凝集粉を含む粉末11が貯留され、処理前粉末搬
送手段25はホッパ26に貯留された粉末11を供給ケ
ース23に供給する搬送手段である。上記ホッパ26の
形状は凝集粉を含む粉末11が臨界にならない形状に形
成される。この搬送手段25として例えばスクリューフ
ィーダを用いると、スクリュー(図示せず)の回転速度
を調整することにより、上記粉末11の供給量を調整可
能となる。供給ケース23と粉末下流側管路24との接
続部には第3摩擦低減部材33が介装される(図1)。
またベース17上には排出ケース27が固定される。こ
の排出ケース27は駆動歯車22b及び従動歯車19d
を覆うにベース17上に固定され、上部にはポット収容
部19aの通孔19eを臨みかつ通孔19eから排出さ
れた粉末12を収容するリング状の粉末収容部27aが
形成される。粉末収容部27aの外周壁27b上端及び
内周壁27c上端は第4摩擦低減部材34(図1及び図
3)を介してポット収容部19aの底面にそれぞれ当接
する(図1)。また粉末収容部27aの外周壁27bに
は排出口27dが形成される。
A substantially conical supply case 23 is provided at the upper end of the mill pot 21 (FIGS. 1 and 4). A supply port 23a is formed at the upper end of the supply case 23, and a discharge port 23b that can be inserted into the opening 21c of the mill pot 21 via the second friction reducing member 32 (FIGS. 1 and 3) is formed at the lower end. (Fig. 1). Supply port 23a of supply case 23
A hopper 26 is connected to the via a powder downstream side pipe line 24 and a pretreatment powder conveying means 25 (FIG. 4). This hopper 2
The powder 11 containing the agglomerated powder is stored in 6, and the pre-treatment powder transfer means 25 is a transfer means for supplying the powder 11 stored in the hopper 26 to the supply case 23. The shape of the hopper 26 is formed so that the powder 11 containing agglomerated powder does not become critical. If, for example, a screw feeder is used as the conveying unit 25, the supply amount of the powder 11 can be adjusted by adjusting the rotation speed of a screw (not shown). A third friction reducing member 33 is interposed at a connecting portion between the supply case 23 and the powder downstream side pipeline 24 (FIG. 1).
A discharge case 27 is fixed on the base 17. The discharge case 27 includes a drive gear 22b and a driven gear 19d.
A ring-shaped powder container 27a is fixed on the base 17 so as to cover the above, and the ring-shaped powder container 27a is formed in the upper part so as to face the through hole 19e of the pot container 19a and contain the powder 12 discharged from the through hole 19e. The upper end of the outer peripheral wall 27b and the upper end of the inner peripheral wall 27c of the powder container 27a are in contact with the bottom surface of the pot container 19a via the fourth friction reducing member 34 (FIGS. 1 and 3) (FIG. 1). A discharge port 27d is formed on the outer peripheral wall 27b of the powder container 27a.

【0011】処理後粉末搬送手段16は図4に詳しく示
すように、N2ガスを貯留するタンク16aと、一端が
タンク16aに接続され他端が供給ケース23に接続さ
れたガス供給管路16bと、一端が排出ケース27の排
出口27dに接続され他端がサイクロン分離器28の入
口に接続された第1搬送管路16cと、一端がサイクロ
ン分離器28のガス排出口に接続され他端がバッグフィ
ルタ29の入口に接続された第2搬送管路16dと、バ
ッグフィルタ29のガス排出口から排出されたN2ガス
をタンク16aに供給するブロア16eとを有する。タ
ンク16a、ガス供給管路16b、ボールミル13、第
1搬送管路16c、サイクロン分離器28、第2搬送管
路16d、バッグフィルタ29及びブロア16eにより
2ガスが循環する閉ループが構成される。タンク16
a内の圧力は大気圧と略同一であり、このタンク16a
はN2ガスを貯留するための他に、ブロア16eにより
発生するN2ガスの脈動を防止する機能も有する。また
ミルポット21、第1搬送管路16c、サイクロン分離
器28、第2搬送管路16d及びバッグフィルタ29内
はブロア16eによるN2の吸引にて負圧状態に保たれ
るように構成される。またガス供給管路16bには流量
調整弁16fが設けられ、ボールミル13に供給される
2ガスの流量が調整される。またタンク16aには図
示しない圧力センサが設けられ、このセンサの検出出力
に基づいてタンク16a内の圧力が所定値未満になる
と、N2ガスが別のタンク(図示せず)から補充管路1
6gを介して補充されるようになっている。
As shown in detail in FIG. 4, the post-treatment powder conveying means 16 is a tank 16a for storing N 2 gas, and a gas supply conduit 16b having one end connected to the tank 16a and the other end connected to the supply case 23. And a first transfer conduit 16c having one end connected to the outlet 27d of the discharge case 27 and the other end connected to the inlet of the cyclone separator 28, and one end connected to the gas outlet of the cyclone separator 28 and the other end. Has a second transfer conduit 16d connected to the inlet of the bag filter 29, and a blower 16e for supplying N 2 gas discharged from the gas outlet of the bag filter 29 to the tank 16a. The tank 16a, the gas supply pipeline 16b, the ball mill 13, the first transport pipeline 16c, the cyclone separator 28, the second transport pipeline 16d, the bag filter 29 and the blower 16e constitute a closed loop in which N 2 gas circulates. Tank 16
The pressure in a is almost the same as the atmospheric pressure, and this tank 16a
The other for storing the N 2 gas, has a function of preventing the pulsation of N 2 gas generated by the blower 16e. The inside of the mill pot 21, the first transfer pipe line 16c, the cyclone separator 28, the second transfer pipe line 16d and the bag filter 29 are kept in a negative pressure state by suctioning N 2 by the blower 16e. A flow rate adjusting valve 16f is provided in the gas supply line 16b to adjust the flow rate of the N 2 gas supplied to the ball mill 13. Further, a pressure sensor (not shown) is provided in the tank 16a, and when the pressure in the tank 16a becomes less than a predetermined value based on the detection output of this sensor, N 2 gas is supplied from another tank (not shown) to the replenishment conduit 1
It is designed to be replenished via 6g.

【0012】サイクロン分離器28は粉砕・混合した粉
末12を含むN2ガスを上記分離器28の内周壁に沿っ
て回転させ、その遠心力により上記粉末12とN2ガス
とを概ね分離するように構成される。またバッグフィル
タ29は内部に収容された布製のバッグ(図示せず)に
より上記サイクロン分離器28で分離できなかった粉末
12とN2ガスとを分離するように構成される。サイク
ロン分離器28の粉末排出口及びバッグフィルタ29の
粉末排出口は粉砕・混合した粉末12を収容する回収容
器14に接続される。この回収容器14の形状は粉砕・
混合した粉末12が臨界にならない形状に形成される。
なお、不活性ガスとしてN2ガスを用いたが、これは一
例であってArガスやHeガス等の不活性ガスを用いて
もよいが、経済的にはN2ガスが望ましい。
The cyclone separator 28 rotates the N 2 gas containing the pulverized and mixed powder 12 along the inner peripheral wall of the separator 28, and generally separates the powder 12 and the N 2 gas by the centrifugal force. Is composed of. Further, the bag filter 29 is configured to separate the powder 12 and the N 2 gas, which cannot be separated by the cyclone separator 28, by a cloth bag (not shown) housed inside. The powder outlet of the cyclone separator 28 and the powder outlet of the bag filter 29 are connected to a collection container 14 that stores the powder 12 that has been crushed and mixed. The shape of this collection container 14 is
The mixed powder 12 is formed into a non-critical shape.
Although N 2 gas is used as the inert gas, this is an example, and an inert gas such as Ar gas or He gas may be used, but N 2 gas is economically preferable.

【0013】このように構成された核燃料粉末、ここで
はウラン・プルトニウム混合酸化物粉末の粉砕・混合方
法を図1〜図5に基づいて説明する。凝集粉を含むウラ
ン・プルトニウム混合酸化物粉末11を粉砕・混合し回
収する装置は、図5に示すようにMOXペレットの製造
工程における粉砕・混合工程とミクロ混合工程において
使用される。MOXペレットを製造するには、先ずPu
2粉末とUO2粉末の混合原料粉と、PuO2−UO2
収粉を粉砕・混合する。PuO2−UO2回収粉はペレッ
ト焼結工程においてペレットに欠けや割れ等が発見され
た場合に再度粉砕した粉末である。混合原料粉と回収粉
の粉砕・混合は、上述した装置により行われる。図1〜
図4に示すように、この装置のミルポット21の直径、
即ち凝集粉を含むウラン・プルトニウム混合酸化物粉末
11及び粉砕・混合したウラン・プルトニウム混合酸化
物粉末12が臨界にならない直径を7〜18cmの範囲
内に設定した。
A method of pulverizing and mixing the nuclear fuel powder thus constituted, here the uranium-plutonium mixed oxide powder, will be described with reference to FIGS. The apparatus for pulverizing / mixing and collecting the uranium / plutonium mixed oxide powder 11 containing agglomerated powder is used in the pulverizing / mixing step and the micromixing step in the manufacturing process of MOX pellets as shown in FIG. In order to manufacture MOX pellets, first, Pu
The mixed raw material powder of O 2 powder and UO 2 powder and the PuO 2 —UO 2 recovered powder are pulverized and mixed. The PuO 2 -UO 2 recovered powder is a powder that is pulverized again when chips or cracks are found in the pellets in the pellet sintering process. The pulverization and mixing of the mixed raw material powder and the recovered powder are performed by the above-mentioned device. Figure 1
As shown in FIG. 4, the diameter of the mill pot 21 of this device,
That is, the diameter at which the uranium-plutonium mixed oxide powder 11 containing agglomerated powder and the uranium-plutonium mixed oxide powder 12 crushed and mixed do not become critical is set within the range of 7 to 18 cm.

【0014】次に、処理前粉末搬送手段25及び供給ケ
ース23を介してミルポット21に、0〜10%の回収
粉を含むウラン・プルトニウム混合粉末11を供給す
る。供給された粉末11はミルポット21の自転及び主
軸回りの公転により生じる遠心力等により、ボール21
eが複雑な運動をするため、このボール21eにより粉
体相互の凝集力は剪断される。この剪断された粉末12
は上記遠心力等の力を殆ど受けなくなりかつ網21fを
通過可能な大きさになるため、N2ガスにより排出ケー
ス27及び第1搬送管路16cを介してサイクロン分離
器28に搬送され、粉末12とN2ガスに概ね分離され
る。粉末12は回収容器14に収容され、未だ粉末12
を含むN2ガスはバッグフィルタ29に搬送されて粉末
12とN2ガスに完全に分離される。
Then, the uranium-plutonium mixed powder 11 containing 0 to 10% of recovered powder is supplied to the mill pot 21 through the pre-treatment powder conveying means 25 and the supply case 23. The supplied powder 11 is dispersed in the balls 21 by the centrifugal force generated by the rotation of the mill pot 21 and the revolution around the spindle.
Since e moves in a complicated manner, the cohesive force between the powder particles is sheared by the balls 21e. This sheared powder 12
Is almost not subjected to the force such as the centrifugal force and has a size capable of passing through the net 21f. Therefore, N 2 gas conveys the powder to the cyclone separator 28 through the discharge case 27 and the first conveying pipe line 16c, and It is roughly separated into 12 and N 2 gas. The powder 12 is stored in the collection container 14 and is still powder 12.
The N 2 gas containing P is conveyed to the bag filter 29 and completely separated into the powder 12 and the N 2 gas.

【0015】回収容器14に収容されたウラン・プルト
ニウム混合酸化物粉末12は図5に示すように、マクロ
混合工程に送られる。マクロ混合工程では予め設定され
た混合比になるようにUO2粉末を添加してV型ブレン
ダ等によって回転混合される。このように混合された酸
化物燃料粉末は造粒工程を経てペレット成形工程でウラ
ン・プルトニウム混合酸化物ペレットに成形される。
The uranium / plutonium mixed oxide powder 12 contained in the recovery container 14 is sent to a macro mixing step, as shown in FIG. In the macro mixing step, UO 2 powder is added so as to have a preset mixing ratio, and the mixture is rotatively mixed by a V-type blender or the like. The oxide fuel powder thus mixed is molded into uranium-plutonium mixed oxide pellets in a pellet forming step through a granulating step.

【0016】[0016]

【発明の効果】以上述べたように、本発明によれば、ミ
ルポットを内部に粉砕媒体を収容した状態で自転させな
がら主軸回りを公転させ、ミルポットの供給部に凝集粉
を含む核燃料粉末及び不活性ガスを供給し、凝集粉を含
む核燃料粉末を不活性ガス雰囲気下でミルポットの自転
と公転により生じる遠心力で粉砕媒体により粉砕し、粉
砕した粉末を上記不活性ガスにより回収容器に回収した
ので、上記粉末がウラン酸化物粉末の場合にはこの粉末
が粉砕媒体により効率よく粉砕され、比較的短時間で均
一に粉砕されたウラン酸化物粉末が得られ、上記粉末が
ウラン・プルトニウム混合酸化物粉末の場合にはこれら
の粉末が効率よく分散されて粉砕・混合され、比較的短
時間で均一に粉砕・混合されたウラン・プルトニウム混
合酸化物粉末が得られる。また核燃料粉末は順次ミルポ
ットに所定量ずつ供給され、このミルポットで粉砕され
た粉末は不活性ガスにより回収容器に回収されるので、
UO2粉末の酸素とウランとの比を一定に保持したまま
連続的に核燃料粉末を粉砕できる。このように連続処理
が可能なため、核燃料粉末の粉砕又は粉砕・混合の処理
能力を大幅に向上できる。
As described above, according to the present invention, the mill pot is revolved around the main axis while rotating in a state where the milling medium is housed therein, and the nuclear fuel powder containing the aggregated powder and the non-mixed powder are contained in the feed portion of the mill pot. Since the active gas is supplied, the nuclear fuel powder containing the agglomerated powder is crushed by the grinding medium by the centrifugal force generated by the rotation and the revolution of the mill pot under the inert gas atmosphere, and the crushed powder is recovered in the recovery container by the inert gas. When the powder is a uranium oxide powder, the powder is efficiently crushed by a crushing medium to obtain a uniformly crushed uranium oxide powder in a relatively short time, and the powder is a uranium-plutonium mixed oxide. In the case of powder, these powders are efficiently dispersed and crushed and mixed to obtain uranium-plutonium mixed oxide powder that is uniformly crushed and mixed in a relatively short time. It is. Further, the nuclear fuel powder is sequentially supplied to the mill pot by a predetermined amount, and the powder pulverized in this mill pot is recovered by the inert gas in the recovery container.
The nuclear fuel powder can be continuously pulverized while keeping the ratio of oxygen and uranium in the UO 2 powder constant. Since continuous processing is possible in this way, the processing capacity for crushing or crushing / mixing nuclear fuel powder can be greatly improved.

【0017】また粉砕・混合するのに比較的長時間を要
する従来のミルポットによる粉砕・混合と比較して、本
発明では核燃料粉末が粉砕媒体と接触する時間が比較的
短いため、粉砕媒体の摩耗粉が粉砕後の核燃料粉末に混
入する量が極めて僅かで済む。またミルポット内は不活
性ガスにより常に満たされているため、核燃料粉末の酸
化を防止でき、ミルポットの直径が核燃料粉末が臨界に
ならない大きさなので、容易に臨界安全管理が行える。
この結果、運転が容易で、保全性の向上を図ることがで
きる。
Further, in the present invention, the contact time of the nuclear fuel powder with the grinding medium is relatively short as compared with the grinding and mixing by the conventional mill pot which requires a relatively long time for the grinding and mixing, so that the grinding medium is worn out. The amount of powder mixed in the nuclear fuel powder after grinding is extremely small. Further, since the inside of the mill pot is constantly filled with the inert gas, the oxidation of the nuclear fuel powder can be prevented, and the diameter of the mill pot is such that the nuclear fuel powder does not become critical, so that the criticality safety control can be easily performed.
As a result, the operation is easy and the maintainability can be improved.

【0018】また粉砕した核燃料粉末を回収容器に搬送
する不活性ガスを、再び供給部に供給することにより、
不活性ガスの全流路を閉ループとすれば、粉砕した核燃
料粉末を回収容器に搬送した不活性ガスを循環させて何
度も使用するため、比較的少量の不活性ガスで済む。ま
たミルポットより不活性ガス下流側を負圧状態に保つこ
とにより、核燃料粉末の散逸を防止できる。更に凝集粉
を含む粉末の供給量及び不活性ガスの供給量のいずれか
一方又は双方を調整可能にすれば、粉砕した核燃料粉末
を更に均一にすることができる。
Further, the inert gas which conveys the pulverized nuclear fuel powder to the recovery container is supplied again to the supply section,
If all the flow paths of the inert gas are closed loop, the crushed nuclear fuel powder is conveyed to the recovery container and the inert gas is circulated and used many times, so that a relatively small amount of the inert gas is required. Further, by maintaining the negative pressure state on the downstream side of the inert gas from the mill pot, it is possible to prevent the nuclear fuel powder from dissipating. Further, if one or both of the supply amount of the powder containing the aggregated powder and the supply amount of the inert gas can be adjusted, the crushed nuclear fuel powder can be made more uniform.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明一実施形態の核燃料粉末を粉砕するボー
ルミルの縦断面図。
FIG. 1 is a vertical sectional view of a ball mill for pulverizing a nuclear fuel powder according to an embodiment of the present invention.

【図2】図1のA−A線断面図。FIG. 2 is a sectional view taken along line AA of FIG.

【図3】図1のB−B線断面図。FIG. 3 is a sectional view taken along line BB of FIG. 1;

【図4】そのボールミルにより粉砕された核燃料粉末の
回収方法を示す構成図。
FIG. 4 is a configuration diagram showing a method for recovering nuclear fuel powder crushed by the ball mill.

【図5】MOXペレットの製造工程図。FIG. 5 is a manufacturing process diagram of MOX pellets.

【符号の説明】[Explanation of symbols]

11 凝集粉を含むウラン・プルトニウム混合酸化物粉
末(凝集分を含む核燃料粉末) 12 粉砕・混合したウラン・プルトニウム混合酸化物
粉末(粉砕した核燃料粉末) 14 回収容器 18 主軸 21 ミルポット 21e ボール(粉砕媒体) 23 供給ケース(供給部)
11 Uranium-plutonium mixed oxide powder containing agglomerated powder (nuclear fuel powder containing agglomerates) 12 Crushed and mixed uranium-plutonium mixed oxide powder (crushed nuclear fuel powder) 14 Recovery container 18 Spindle 21 Millpot 21e ball (crushing medium) ) 23 Supply case (supply section)

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 主軸(18)の軸方向周囲に配設されポット
(21)内に粉砕媒体(21e)を収容しかつ核燃料粉末(11,12)
が臨界にならない直径を有する複数のミルポット(21)を
自転させながら前記主軸(18)回りに公転させる工程と、 凝集粉を含む核燃料粉末(11)を前記ミルポット(21)の供
給部(23)に搬送する工程と、 前記供給部(23)に不活性ガスを供給する工程と、 前記供給部(23)から前記粉末(11)を前記ミルポット(21)
内に供給し前記不活性ガス雰囲気下で前記自転と公転に
より生じる遠心力で前記粉砕媒体(21e)により前記凝集
粉を含む粉末(11)を粉砕する工程と、 前記粉砕した粉末(12)を前記不活性ガスにより前記粉末
(12)が臨界にならない形状の回収容器(14)に回収する工
程とを含む核燃料粉末の粉砕方法。
1. A pot arranged around the main shaft (18) in the axial direction.
(21) contains grinding medium (21e) and nuclear fuel powder (11, 12)
A step of revolving a plurality of mill pots (21) having a diameter that does not become critical around the main shaft (18), and supplying a nuclear fuel powder (11) containing agglomerated powder (23) to the mill pot (21). And a step of supplying an inert gas to the supply part (23), the powder (11) from the supply part (23) to the mill pot (21)
A step of pulverizing the powder (11) containing the agglomerated powder by the pulverizing medium (21e) by the centrifugal force generated by the rotation and the revolution under the inert gas atmosphere, and the pulverized powder (12). The powder by the inert gas
A method of pulverizing nuclear fuel powder, comprising the step of collecting (12) in a recovery container (14) having a shape that does not become critical.
【請求項2】 粉砕した核燃料粉末(12)を回収容器(14)
に搬送する不活性ガスが供給部(23)に供給され、前記前
記不活性ガスの全流路が閉ループを構成する請求項1記
載の核燃料粉末の粉砕方法。
2. A container (14) for collecting the crushed nuclear fuel powder (12).
2. The method for pulverizing nuclear fuel powder according to claim 1, wherein the inert gas to be conveyed to is supplied to the supply unit (23), and all the flow paths of the inert gas form a closed loop.
【請求項3】 凝集粉を含む粉末の供給量及び不活性ガ
スの供給量のいずれか一方又は双方を調整可能にした請
求項1又は2記載の核燃料粉末の粉砕方法。
3. The method for pulverizing nuclear fuel powder according to claim 1, wherein one or both of the supply amount of the powder containing the aggregated powder and the supply amount of the inert gas can be adjusted.
JP7340285A 1995-12-27 1995-12-27 Crushing method for nuclear fuel powder Pending JPH09178890A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7340285A JPH09178890A (en) 1995-12-27 1995-12-27 Crushing method for nuclear fuel powder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7340285A JPH09178890A (en) 1995-12-27 1995-12-27 Crushing method for nuclear fuel powder

Publications (1)

Publication Number Publication Date
JPH09178890A true JPH09178890A (en) 1997-07-11

Family

ID=18335484

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7340285A Pending JPH09178890A (en) 1995-12-27 1995-12-27 Crushing method for nuclear fuel powder

Country Status (1)

Country Link
JP (1) JPH09178890A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100969942B1 (en) * 2008-12-26 2010-07-14 한전원자력연료 주식회사 Crusher of raw materials
JP2013504049A (en) * 2009-09-02 2013-02-04 コミッサリア ア ロンネルジー アトミック エ オ ゾンネルジー ザルテルナティーフ Method for preparing a porous nuclear fuel based on at least one minor actinide

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100969942B1 (en) * 2008-12-26 2010-07-14 한전원자력연료 주식회사 Crusher of raw materials
JP2013504049A (en) * 2009-09-02 2013-02-04 コミッサリア ア ロンネルジー アトミック エ オ ゾンネルジー ザルテルナティーフ Method for preparing a porous nuclear fuel based on at least one minor actinide

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