JP2555347B2 - Fuel element helium leak detection test method - Google Patents
Fuel element helium leak detection test methodInfo
- Publication number
- JP2555347B2 JP2555347B2 JP62086662A JP8666287A JP2555347B2 JP 2555347 B2 JP2555347 B2 JP 2555347B2 JP 62086662 A JP62086662 A JP 62086662A JP 8666287 A JP8666287 A JP 8666287A JP 2555347 B2 JP2555347 B2 JP 2555347B2
- Authority
- JP
- Japan
- Prior art keywords
- chamber
- fuel element
- helium
- gas replacement
- gas
- 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.)
- Expired - Lifetime
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
- Monitoring And Testing Of Nuclear Reactors (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は燃料要素１本毎にオンラインでヘリウムガス
の漏れ量を高精度に検出する燃料要素のヘリウムリーク
検出試験方法に関する。TECHNICAL FIELD The present invention relates to a helium leak detection test method for a fuel element, which detects the leak amount of helium gas online with high accuracy for each fuel element.
従来のヘリウムリーク試験は、例えば、「軽水炉のふ
るまい」（原子力安全保安研究協会）に示されているよ
うに、複数の燃料要素を集合体に組立てた後に行う方式
と、複数（10〜20数本）の燃料要素をひとつのパレツト
に並べた状態で行う方式とがある。The conventional helium leak test, for example, as shown in "Light Water Reactor Behavior" (Nuclear Safety and Security Research Association), is performed after assembling a plurality of fuel elements into an assembly. There is a method in which fuel elements (book) are arranged in one pallet.
パレツトを用いる方式にあつても、従来はペレツト充
填から上部端栓溶接までの工程でも、グローブボツクス
とオープンボツクスとの間を通過させて製造する必要が
なく、ガス置換チヤンバは不必要である。しかし、最近
になつて毒性の強い核燃料ペレツトを能率よく生産する
為に、ペレツト充填及び上部端栓溶接工程迄は負圧雰囲
気のグローブボツクスで取扱い、それから後の工程では
ガス置換チヤンバを通して空気雰囲気で取り扱う工程に
なつている。Even in the method using the pallet, conventionally, even in the steps from the pellet filling to the upper end plug welding, it is not necessary to pass through the glove box and the open box for manufacturing, and the gas replacement chamber is unnecessary. However, in recent years, in order to efficiently produce highly toxic nuclear fuel pellets, they are handled in a negative pressure glove box until the pellet filling and upper end plug welding steps, and then in the air atmosphere through a gas replacement chamber in the subsequent steps. It is in the process of handling.
第３図は、燃料要素をパレツトに並べてヘリウムリー
ク試験を行う方式を採用した従来の系統構成の一部を示
す図である。この系統部分は、不活性ガス負圧（例え
ば、−30mmAq±5mmAq）に維持されたグローブボツクス
Ａと、ガス置換チヤンバＢと、大気圧のオープンボツク
スＣと、ヘリウムリーク試験設備Ｄとからなる。グロー
ブボツクスＡは、前工程から供給される被覆管ペレツト
やスプリング等を挿入しヘリウムを充填した後に上部端
栓を溶接する場所である。オープンボツクスＣは、そう
して形成された燃料要素の溶接部等の外観を検査する場
所である。オープンボツクスＣでの検査終了後、燃料要
素はヘリウムリーク試験設備Ｄに送られ、所定本数まで
パレツトに蓄えられ、ヘリウムリーク試験に付される。
ガス置換チヤンバＢは、グローブボツクスＡ側の負圧を
乱さず、しかも大気中に核物質を飛散させないように、
上部端栓を密封した燃料要素をオープンボツクスＣ側に
送るために設置されている。FIG. 3 is a diagram showing a part of a conventional system configuration in which a fuel element is arranged in a pallet and a helium leak test is performed. This system part consists of a glove box A maintained at an inert gas negative pressure (for example, −30 mmAq ± 5 mmAq), a gas replacement chamber B, an atmospheric open box C, and a helium leak test facility D. The glove box A is a place where the cladding pipe pellets and springs supplied from the previous step are inserted, helium is filled, and then the upper end plug is welded. The open box C is a place where the appearance of the welded portion of the fuel element thus formed is inspected. After completion of the inspection in the open box C, the fuel elements are sent to the helium leak test equipment D, stored in a pallet up to a predetermined number, and subjected to the helium leak test.
The gas replacement chamber B does not disturb the negative pressure on the side of the globe box A, and also does not scatter the nuclear material into the atmosphere.
It is installed to send the fuel element with the upper end plug sealed to the open box C side.
次に、これらの系統部分での操作の概要を説明する。
グローブボツクスＡ内のヘリウム雰囲気で燃料要素の上
部端栓を溶接する。この燃料要素をグローブボツクスＡ
からオープンボツクスＣに送る際に、オープンボツクス
Ｃ側の空気がグローブボツクスＡ側のヘリウムガスに混
入しないように、またグローブボツクスＡ側の核物質を
オープンボツクスＣ側に飛散させないように、まず、ガ
ス置換チヤンバＢの両側のシヤツタを閉じた状態で、ガ
ス置換チヤンバＢ内を一旦10-2Torrまで真空排気する。
次に、ヘリウムガスをガス置換チヤンバＢに導入し、グ
ローブボツクスＡと同じ負圧（−30mmAq±5mmAq）にす
る。そこで、溶接完了の燃料要素をグローブボツクスＡ
からガス置換チヤンバＢに引き出し、グローブボツクス
Ａ側のシヤツタを閉じる。その後、オープンボツクスＣ
側のシヤツタを開き、燃料要素を送り出す。オープンボ
ツクスＣでは、燃料要素の溶接部等の外観を検査し、ヘ
リウムリーク試験設備Ｄのパレツトに送る。ヘリウムリ
ーク試験設備Ｄは、所定本数の燃料要素が送られてきた
ところで、パレツトごとにヘリウムリーク試験を行な
い、次工程に送る。Next, the outline of the operation in these system parts will be described.
Weld the upper end plug of the fuel element in a helium atmosphere in the glove box A. This fuel element is Grove Box A
When sending from the open box C to the open box C, the air on the open box C side should not be mixed with the helium gas on the glove box A side, and the nuclear material on the glove box A side should not be scattered to the open box C side. With the shutters on both sides of the gas replacement chamber B closed, the gas replacement chamber B is temporarily evacuated to 10 -2 Torr.
Next, helium gas is introduced into the gas replacement chamber B to make the same negative pressure (-30 mmAq ± 5 mmAq) as the glove box A. Therefore, the fuel element for the completion of welding is replaced by the glove box A.
To the gas replacement chamber B, and close the shutter on the glove box A side. After that, open box C
Open the side shatter and deliver the fuel element. In the open box C, the appearance of the welded portion of the fuel element is inspected and sent to the pallet of the helium leak test facility D. When a predetermined number of fuel elements have been sent, the helium leak test facility D performs a helium leak test for each pallet and sends it to the next step.
さて、複数の燃料要素を集合体に組み立てた後にヘリ
ウムリーク試験を行う方式では、リークが検出された場
合、既に組み立てられたたくさんの燃料要素のどれから
リークが生じているのか分からず、何度も検査を繰り返
さなければならなかつた。By the way, in the method of conducting a helium leak test after assembling a plurality of fuel elements into an assembly, if a leak is detected, it is not possible to know which of the many fuel elements already assembled is causing the leak. I had to repeat the inspection.
一方、第３図のパレツトに燃料要素を蓄えてヘリウム
リーク試験を行う従来例でも、状況はあまり改善されて
いない。On the other hand, even in the conventional example in which the fuel element is stored in the pallet shown in FIG. 3 and the helium leak test is performed, the situation is not so much improved.
この方法では、通常数本から10数本の燃料要素をパレ
ツトに蓄えて試験しているので、リークが発生してもパ
レツト単位での合否判定しかできず、リークがある燃料
要素を特定するには、オフラインで１本毎に全数検査が
必要となり、二度手間となる。In this method, normally several to ten or more fuel elements are stored in a pallet and tested, so even if a leak occurs, only pass / fail judgment can be made on a pallet basis. Requires 100% inspection for each line off-line, which is troublesome twice.
さらに問題なのは、パレツトからの放出ガスである。
第４図により、それを説明する。図において、ａは、パ
レツトおよび燃料要素が無いときのヘリウムリーク試験
チヤンバそのものの放出ガス量（バツクグラウンド）、
ｂは、パレツトおよび燃料要素が無い状態で例えば３×
10-8Torr・・secの標準リーク線源からヘリウムガス
を放出させたときの放出ガス量、ｃは、パレツトおよび
ヘリウムガスを封入しない燃料要素を挿入したときの放
出ガス量（バツクグラウンド）、c2は、パレツトおよび
ヘリウムガスを封入した燃料要素を挿入したときの放出
ガス量、ｄは、ヘリウムガスを封入しない燃料要素のみ
を挿入したときの放出ガス量（バツクグラウンド）、ｅ
は、例えば１×10-8Torr./secの合否判定基準レベル
である。A further problem is the gas released from the pallet.
This will be described with reference to FIG. In the figure, a is the amount of released gas (back ground) from the helium leak test chamber itself when there is no pallet and fuel element,
b is, for example, 3 × with no pallet and fuel element
The amount of emitted gas when helium gas is released from a standard leak radiation source of 10 -8 Torr ·· sec, c is the amount of emitted gas (back ground) when a pallet and a fuel element that does not enclose helium gas are inserted, c 2 is the amount of gas released when a fuel element containing pallet and helium gas is inserted, d is the amount of gas released when only a fuel element without helium gas is inserted (back ground), e
Is a pass / fail judgment reference level of, for example, 1 × 10 −8 Torr./sec.
この場合、ヘリウムリーク試験の検出感度ｆは、（３
×10-8Torr・/sec）／（ｂ−ａ）で与えられる。ま
た、実際の燃料要素の判定は、（c2−ｃ）×ｆが所定の
基準値ｅ以下か否かを測ることによりなされる。In this case, the detection sensitivity f of the helium leak test is (3
× 10 −8 Torr · / sec) / (ba). Further, the actual determination of the fuel element is made by measuring whether or not (c 2 −c) × f is equal to or less than a predetermined reference value e.
ヘリウムリーク試験設備で用いるパレツトは、前回の
試験以後、様々な試験工程を経る。そのため、パレツト
自体の放出ガス量をその都度測定する必要があつた。し
かも、パレツトには機械油や水分等が付着してパレツト
そのものの放出ガス量が一定でなく、パレツトからの放
出ガス量があまりに大きく、燃料要素のヘリウムリーク
試験の精度を低下させる問題があつた。The pallet used in the helium leak test facility goes through various test steps since the previous test. Therefore, it was necessary to measure the amount of gas released from the pallet itself each time. Moreover, the amount of gas released from the pallet itself was not constant due to the adhesion of mechanical oil, water, etc. to the pallet, and the amount of gas released from the pallet was too large, which reduced the accuracy of the helium leak test for fuel elements. .
すなわち、パレツトおよびヘリウムガスを封入しない
燃料要素を挿入したときの放出ガス量ｃが、合否判定基
準ｅをはるかに越えてしまい、それが安定しないので、
一定のバツクグラウンドｃとして計算条件に入れてお
き、実際の測定結果c2から、（c2−ｃ）×ｆが合否判定
基準ｅ以下を満足しているかどうかを判定することに熟
練を要していた。通常、燃料要素の合否判定は、10-8To
rr・/sec程度の漏れを測定するので、チヤンバは10-5
Torr程度まで真空排気し、10-8/10-5＝10-3/secの漏
れ量を測定する。パレツトが汚れ、規定時間内のチヤン
バの真空度が例えば10-3Torrになると、10-8/10-3＝10
-5/secの漏れ量を測ることになり、測定が益々困難で
ある。That is, the amount c of released gas when the fuel element that does not enclose the pallet and helium gas is inserted far exceeds the acceptance criterion e, and it is not stable.
It takes a certain amount of skill to determine whether (c 2 −c) × f satisfies the pass / fail criterion e or less from the actual measurement result c 2 in advance as a constant back ground c. Was there. Normally, the pass / fail judgment of fuel element is 10 -8 To
Since leaks of about rr ・ / sec are measured, the chamber is 10 -5
Evacuate to about Torr and measure the leak rate of 10 -8 / 10 -5 = 10 -3 / sec. If the pallet becomes dirty and the vacuum level of the chamber within the specified time reaches 10 -3 Torr, for example, 10 -8 / 10 -3 = 10
The leak rate of -5 / sec must be measured, which makes the measurement even more difficult.
結局は、ヘリウムリーク試験直前でパレツト自体の放
出ガス量をオンラインで測定しなければならず、手間が
かかるとともに、燃料要素のヘリウムリークの測定精度
が上がらなかつた。Eventually, the amount of gas released from the pallet itself had to be measured online immediately before the helium leak test, which was troublesome and the helium leak measurement accuracy of the fuel element could not be improved.
本発明の目的は、燃料要素１本毎にオンラインでヘリ
ウムガスの漏れ量を高精度に検出する燃料要素のヘリウ
ムリーク検出試験方法を提供することにある。An object of the present invention is to provide a helium leak detection test method for a fuel element, which detects the leak amount of helium gas online with high accuracy for each fuel element.
本発明は、上記目的を達成するために、燃料要素の上
部端栓を溶接する負圧の第１室へ溶接された燃料要素の
上部端栓を外観検査する大気圧の第２室雰囲気が混入し
ないように前記第１室と前記第２室間に配置されたガス
置換チヤンバを真空に吸引後ヘリウムを供給して前記第
１室と同じ負圧に調整する工程と、ヘリウムを封入せざ
る１本の燃料要素を前記ガス置換チヤンバへ搬入する工
程と、前記ガス置換チヤンバを所定の真空に吸引した後
に前記ガス置換チヤンバ内の圧力上昇ｄを検出する工程
と、上部端栓を溶接し外観検査の対象となる１本の燃料
要素を前記ガス置換チヤンバへ搬入する工程と、前記ガ
ス置換チヤンバを所定の真空に吸引した後に前記ガス置
換チヤンバ内の圧力上昇ｐを検出する工程と、該圧力上
昇ｐから前記圧力上昇ｄを差し引いた値と所定の合否判
定基準値とを比較して前記燃料要素からのヘリウムリー
クを判定する工程とを有する燃料要素のヘリウムリーク
検出試験方法を提供するものである。In order to achieve the above-mentioned object, the present invention mixes the atmosphere of the second chamber atmosphere of the atmospheric pressure for visual inspection of the upper end plug of the welded fuel element with the first chamber of the negative pressure for welding the upper end plug of the fuel element. In order not to do so, the gas replacement chamber disposed between the first chamber and the second chamber is evacuated to a vacuum, and then helium is supplied to adjust the negative pressure to the same negative pressure as that of the first chamber. The step of bringing the fuel element of the book into the gas replacement chamber, the step of detecting the pressure increase d in the gas replacement chamber after sucking the gas replacement chamber into a predetermined vacuum, and the appearance inspection by welding the upper end plug. The step of bringing in one fuel element to be subject to the gas replacement chamber, the step of detecting the pressure increase p in the gas replacement chamber after the gas replacement chamber is evacuated to a predetermined vacuum, and the pressure increase. Above the pressure from p By comparing the values obtained by subtracting the d with a predetermined acceptance criteria value it is intended to provide a helium leak detection test method for a fuel element and a step of determining helium leak from the fuel element.
第２図を参照して、本発明の構成の概要を説明する。
この第２図と従来例を示す第３図との比較から明らかな
ように、ヘリウムリーク試験の最大の外乱ノイズ源とな
つているパレツトをヘリウムリーク試験設備Ｄに持ち込
まなければ、その影響から解放される。ヘリウムを封入
せざる燃料要素の真空中における圧力上昇ｄを検出して
バツクグラウンドとし、検査対象となる燃料要素の真空
中における圧力上昇ｐを検出し、圧力上昇ｐからバツク
グラウンドの圧力上昇ｄを差し引いた値と所定の合否判
定基準値とを比較してヘリウムリークを判定することよ
り、ヘリウムリークを高精度に測定できる。The outline of the configuration of the present invention will be described with reference to FIG.
As is clear from the comparison between FIG. 2 and FIG. 3 showing the conventional example, if the pallet, which is the largest disturbance noise source in the helium leak test, is not brought into the helium leak test equipment D, it will be released from its influence. To be done. The pressure increase d in the vacuum of the fuel element that does not contain helium is detected as the background, and the pressure increase p in the vacuum of the fuel element to be inspected is detected, and the pressure increase d of the background is calculated from the pressure increase p. The helium leak can be measured with high accuracy by comparing the subtracted value and a predetermined pass / fail judgment reference value to judge the helium leak.
第１図は、本発明によるガス置換チヤンバの一実施例
を示す系統図である。図において、１は不活性ガス（ヘ
リウム）の負圧に維持された第１室（グローブボツク
ス）、２はそこで作られ空気雰囲気中に運び出される燃
料要素、３は第１室と空気雰囲気の第２室（オープンボ
ツクス）とをつなぐガス置換チヤンバ本体、４は真空粗
引系、５は標準リーク排気系、６は本引排気系、７はヘ
リウムリークテスト系、８はヘリウム供給量制御系、９
は真空計（ピラニ真空計）、10は開閉弁（エア作動
弁）、11は差圧真空計、12はシヤツタ、13は電磁弁、14
は電離真空計、15は標準線源、16は電磁弁、17は真空ス
イツチである。FIG. 1 is a system diagram showing an embodiment of a gas replacement chamber according to the present invention. In the figure, 1 is a first chamber (grove box) maintained at a negative pressure of an inert gas (helium), 2 is a fuel element created therein and is carried into an air atmosphere, and 3 is a first chamber and an air atmosphere. Gas replacement chamber body connecting two chambers (open box), 4 vacuum roughing system, 5 standard leak exhaust system, 6 main exhaust system, 7 helium leak test system, 8 helium supply control system, 9
Is a vacuum gauge (Pirani vacuum gauge), 10 is an open / close valve (air operated valve), 11 is a differential pressure vacuum gauge, 12 is a shutter, 13 is a solenoid valve, 14
Is an ionization vacuum gauge, 15 is a standard radiation source, 16 is a solenoid valve, and 17 is a vacuum switch.
このように構成したガス置換チヤンバを用いて、ヘリ
ウムリーク試験をしながら、第１室から第２室に燃料要
素を１本ずつ移送する作業を説明する。An operation of transferring the fuel elements one by one from the first chamber to the second chamber while performing a helium leak test using the gas replacement chamber thus configured will be described.
まず、両側のシヤツタ12A,12Bを閉じ、スイツチ17を
入れて真空粗引系４により、チヤンバ３を所定の真空
（例えば１×10-2Torr）まで真空に引く。First, the shutters 12A and 12B on both sides are closed, the switch 17 is inserted, and the chamber 3 is evacuated to a predetermined vacuum (for example, 1 × 10 -2 Torr) by the vacuum evacuation system 4.
ここでもし、そのままシヤツタ12Aを開き燃料要素２
を搬出すると、第１室１からガス置換チヤンバ３に汚染
されたヘリウムガスが流れて、図示しない第１室負圧監
視装置が作動し、第１室側のヘリウム制御系が働き、規
定の負圧に戻るまで燃料要素を搬出できないので、タイ
ムロスにつながる。Here too, open the shutter 12A as it is and fuel element 2
When the gas is carried out, the helium gas contaminated by the gas displacement chamber 3 flows from the first chamber 1, the first chamber negative pressure monitoring device (not shown) is activated, and the helium control system on the first chamber side operates to operate the specified negative pressure. Since the fuel element cannot be carried out until it returns to pressure, it leads to time loss.
これを防ぐために、ガス置換チヤンバ３を真空引き
後、ヘリウム供給口からヘリウム流量制御系８を介して
ヘリウムを供給し、第１室と同じ負圧（例えば−30mmA
q）にする。In order to prevent this, after the gas replacement chamber 3 is evacuated, helium is supplied from the helium supply port through the helium flow rate control system 8, and the same negative pressure as that in the first chamber (eg, -30 mmA
q).
この場合、所定の真空（１×10-2Torr）から第１室１
の真空−30mmAq（約758Torr）よりも若干低い値（以下
Ａ点という）までは、第１管路の大流量の絞りを通じ
て、10Torr/sec以上の圧力勾配で流す。Ａ点圧力から−
30mmAqまでは、第２管路の小流量の絞りを通じて、7Tor
r/sec以下の圧力勾配で流す。In this case, from the predetermined vacuum (1 × 10 -2 Torr) to the first chamber 1
Up to a value (hereinafter referred to as point A) slightly lower than the vacuum of -30 mmAq (about 758 Torr), flow with a pressure gradient of 10 Torr / sec or more through the large flow restriction of the first conduit. From point A pressure-
Up to 30mmAq, 7Tor through the small flow throttle of the 2nd pipeline
Flow with a pressure gradient of r / sec or less.
ここで、デジタルマノメータを用いた差圧計11の耐圧
保護のために、一定の真空（−2000mmAq）になつてから
閉く開閉弁10を作動させる信号を、ピラニ真空計９から
得ている。また、ヘリウム供給量制御系８の第１管路と
第２管路との切換信号は、差圧計11から出される。Here, in order to protect the differential pressure gauge 11 using a digital manometer from pressure resistance, a signal for activating the on-off valve 10 which is closed after a constant vacuum (−2000 mmAq) is obtained from the Pirani vacuum gauge 9. Further, a switching signal between the first pipeline and the second pipeline of the helium supply amount control system 8 is output from the differential pressure gauge 11.
このように途中で流量を変えるのは、グローブボツク
ス内で温度変化を起こすことなく、短時間に精度良く目
標圧力を達成するためである。The reason for changing the flow rate on the way is to achieve the target pressure accurately in a short time without causing a temperature change in the glove box.
第１室１とガス置換チヤンバ３の負圧が同じになつた
ら、シヤツタ12Aを開き、１本の燃料要素をガス置換チ
ヤンバ３に挿入する。When the negative pressures in the first chamber 1 and the gas replacement chamber 3 become the same, the shutter 12A is opened and one fuel element is inserted into the gas replacement chamber 3.
次に、第１室１側のシヤツタ12Aを閉じ、再度、真空
粗引系４により真空スイツチ17の設定圧（１×10-2Tor
r）まで粗引きする。Next, the shutter 12A on the side of the first chamber 1 is closed, and the set pressure (1 × 10 -2 Torr of the vacuum switch 17 is again set by the vacuum roughing system 4.
Roughly pull up to r).
さらに、電離真空計でモニタしながら本引排気系６に
より１×10-5Torrまで真空排気する。Further, the main exhaust system 6 is evacuated to 1 × 10 −5 Torr while monitoring with an ionization vacuum gauge.
そこで、バツクグラウンドの影響により、ガス置換チ
ヤンバ内の圧力が１×10-5Torrから上昇する度合を記録
する。Therefore, the degree to which the pressure inside the gas displacement chamber rises from 1 × 10 -5 Torr due to the influence of the background is recorded.
この場合、バツクグラウンドを低く抑え、感度を高め
るためには、できるだけ高真空にして測定する必要があ
る。現在、実験室的には１×10-10Torr程度でチヤンバ
内を真空排気することも出来るが、生産ラインで大気圧
からさらに超真空に頻繁に繰り返し動作させることは、
技術的に困難であり、生産性も上がらなくなるので１×
10-5Torr程度の真空度で測定するのが実用的である。本
ガス置換チヤンバ３では、バツクグラウンドの大きな不
安定要因であつたパレツトをヘリウムリーク試験部分に
持ち込まないので、バツクグラウンドは安定し、第４図
のｃに比較してかなり低い値ｄになる。In this case, in order to keep the background low and increase the sensitivity, it is necessary to make the measurement as high vacuum as possible. At present, in the laboratory, it is possible to evacuate the chamber at about 1 × 10 -10 Torr, but it is not possible to repeatedly operate from atmospheric pressure to ultra-vacuum repeatedly on the production line.
1 × because it is technically difficult and productivity will not increase
It is practical to measure at a vacuum degree of about 10 -5 Torr. In this gas replacement chamber 3, since the pallet, which is a major instability factor of the background, is not brought into the helium leak test portion, the background is stable and the value d is considerably lower than that in c of FIG.
ガス置換チヤンバ３に燃料要素２を１本挿入し、所定
の真空度まで引いた後、数分経過したときのガス置換チ
ヤンバ３の圧力上昇をｐとすると、（ｐ−ｄ）×ｆを求
め、第４図のｅと比較し、合否を判定する。When one fuel element 2 is inserted into the gas replacement chamber 3 and a predetermined vacuum degree is drawn, and the pressure increase of the gas replacement chamber 3 after a few minutes has elapsed is p, (p−d) × f is calculated. , And e in FIG.
なお、標準リーク排気系は、操業前にガス置換チヤン
バ３を１×10-5Torrまで真空排気し、すべての弁を閉じ
てチヤンバに入つてくるバツクグラウンドａを測定して
おき、次に、標準線源から３×10-8Torr・/secのガス
を放出させ、バツクグラウンドｂを測定し、装置感度ｆ
を求めるためのものである。The standard leak exhaust system evacuates the gas replacement chamber 3 to 1 × 10 -5 Torr before operation, closes all valves, and measures the back ground a entering the chamber. Gas of 3 × 10 -8 Torr · / sec was emitted from the standard radiation source, the background ground b was measured, and the device sensitivity f
Is for seeking.
本発明によれば、ヘリウムを封入せざるバツクグラウ
ンド測定のための燃料要素と、ヘリウムを封入した製品
となる燃料要素のそれぞれの真空中における圧力上昇値
を検出し、バックグラウンドを差し引いた圧力上昇値と
合否判定基準値とを比較してヘリウムリークを判定する
ことより、ヘリウムリークを高精度に測定できる効果が
得られる。According to the present invention, the pressure increase value in which the background is subtracted by detecting the pressure increase value in the vacuum of each of the fuel element for measuring the background without enclosing helium and the fuel element as the product in which helium is contained. By determining the helium leak by comparing the value with the pass / fail judgment reference value, the effect that the helium leak can be measured with high accuracy can be obtained.
第１図は本発明によるガス置換チヤンバの一実施例を示
す系統図、第２図は本発明のガス置換チヤンバの構成の
概要を示す図、第３図はガス置換チヤンバとヘリウムリ
ーク試験設備を分けて設けた従来の系統構成の概略を示
す図、第４図はヘリウムリーク試験の漏れ量測定のガス
レベルの関係を示す図である。 １……第１室（グローブボツクス）、２……燃料要素、
３……ガス置換チヤンバ、４……真空粗引系、５……標
準リーク排気系、６……本引排気系、７……ヘリウムリ
ークテスト系、８……ヘリウム供給量制御系、９……ピ
ラニ真空計、10……開閉弁、11……差圧真空計、12……
シヤツタ、13……電磁弁、14……電磁真空計、15……標
準線源、16……電磁弁、17……真空スイツチ。FIG. 1 is a system diagram showing an embodiment of a gas replacement chamber according to the present invention, FIG. 2 is a diagram showing an outline of the configuration of the gas replacement chamber of the present invention, and FIG. 3 is a gas replacement chamber and a helium leak test facility. FIG. 4 is a diagram showing an outline of a conventional system configuration provided separately, and FIG. 4 is a diagram showing a relationship of gas levels in leak amount measurement of a helium leak test. 1 ... First chamber (grove box), 2 ... Fuel element,
3 ... Gas replacement chamber, 4 ... Vacuum evacuation system, 5 ... Standard leak exhaust system, 6 ... Main exhaust system, 7 ... Helium leak test system, 8 ... Helium supply control system, 9 ... … Pirani vacuum gauge, 10 …… Open / close valve, 11 …… Differential pressure gauge, 12 ……
Shutter, 13 ... Solenoid valve, 14 ... Electromagnetic vacuum gauge, 15 ... Standard source, 16 ... Solenoid valve, 17 ... Vacuum switch.
Claims (1)
室へ溶接された燃料要素の上部端栓を外観検査する大気
圧の第２室雰囲気が混入しないように前記第１室と前記
第２室間に配置されたガス置換チヤンバを真空に吸引後
ヘリウムを供給して前記第１室と同じ負圧に調整する工
程と、 ヘリウムを封入せざる１本の燃料要素を前記ガス置換チ
ヤンバへ搬入する工程と、 前記ガス置換チヤンバを所定の真空に吸引した後に前記
ガス置換チヤンバ内の圧力上昇ｄを検出する工程と、 上部端栓を溶接し外観検査の対象となる１本の燃料要素
を前記ガス置換チヤンバへ搬入する工程と、 前記ガス置換チヤンバを所定の真空に吸引した後に前記
ガス置換チヤンバ内の圧力上昇ｐを検出する工程と、 該圧力上昇ｐから前記圧力上昇ｄを差し引いた値と所定
の合否判定基準値とを比較して前記燃料要素からのヘリ
ウムリークを判定する工程と、 を有することを特徴とする燃料要素のヘリウムリーク検
出試験方法。1. A negative first pressure welding upper plug of a fuel element.
A visual inspection of the upper end plug of the fuel element welded to the chamber is performed. After suctioning the gas replacement chamber disposed between the first chamber and the second chamber into a vacuum so that the atmosphere in the second chamber at atmospheric pressure is not mixed, helium is introduced. To adjust the negative pressure to the same negative pressure as in the first chamber, to bring in one fuel element that does not contain helium into the gas replacement chamber, and to suction the gas replacement chamber to a predetermined vacuum. After that, a step of detecting a pressure increase d in the gas replacement chamber, a step of welding one upper end plug and carrying in one fuel element to be inspected for visual inspection into the gas replacement chamber, and a predetermined operation of the gas replacement chamber. From the fuel element by comparing the value obtained by subtracting the pressure increase d from the pressure increase p with a predetermined pass / fail judgment reference value with the step of detecting the pressure increase p in the gas replacement chamber after suctioning to the vacuum. of Helium leak detection test method of the fuel elements and having a a step of determining Riumuriku.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62086662A JP2555347B2 (en) | 1987-04-08 | 1987-04-08 | Fuel element helium leak detection test method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62086662A JP2555347B2 (en) | 1987-04-08 | 1987-04-08 | Fuel element helium leak detection test method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63252296A JPS63252296A (en) | 1988-10-19 |
| JP2555347B2 true JP2555347B2 (en) | 1996-11-20 |
Family
ID=13893244
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62086662A Expired - Lifetime JP2555347B2 (en) | 1987-04-08 | 1987-04-08 | Fuel element helium leak detection test method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2555347B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2164672C1 (en) * | 1999-07-23 | 2001-03-27 | Открытое акционерное общество "Машиностроительный завод" | Process of uninterrupted test of leak-proofness of fuel elements and gear for its realization |
| JP4595152B2 (en) * | 2000-02-01 | 2010-12-08 | パナソニック株式会社 | Vacuum exhaust apparatus and method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4117333A (en) * | 1977-04-29 | 1978-09-26 | Westinghouse Electric Corp. | Nuclear fuel element leak detection system |
| JPS60181693A (en) * | 1984-02-28 | 1985-09-17 | 株式会社島津製作所 | Manufacturing system of fuel element for nuclear reactor |
-
1987
- 1987-04-08 JP JP62086662A patent/JP2555347B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63252296A (en) | 1988-10-19 |
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