JPH0145595B2 - - Google Patents
Info
- Publication number
- JPH0145595B2 JPH0145595B2 JP6804681A JP6804681A JPH0145595B2 JP H0145595 B2 JPH0145595 B2 JP H0145595B2 JP 6804681 A JP6804681 A JP 6804681A JP 6804681 A JP6804681 A JP 6804681A JP H0145595 B2 JPH0145595 B2 JP H0145595B2
- Authority
- JP
- Japan
- Prior art keywords
- detector
- foil
- liquid
- drum
- alpha
- 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
Links
- 239000007788 liquid Substances 0.000 claims description 17
- 239000011888 foil Substances 0.000 claims description 11
- 239000007789 gas Substances 0.000 claims description 10
- 238000005259 measurement Methods 0.000 claims description 10
- 238000004140 cleaning Methods 0.000 claims description 8
- 229910052778 Plutonium Inorganic materials 0.000 claims description 7
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 claims description 7
- 230000005855 radiation Effects 0.000 claims description 7
- 239000001307 helium Substances 0.000 claims description 4
- 229910052734 helium Inorganic materials 0.000 claims description 4
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 4
- 239000011324 bead Substances 0.000 claims description 3
- 238000009833 condensation Methods 0.000 claims description 3
- 230000005494 condensation Effects 0.000 claims description 3
- 239000011521 glass Substances 0.000 claims description 3
- 230000035945 sensitivity Effects 0.000 description 5
- 238000005202 decontamination Methods 0.000 description 3
- 230000003588 decontaminative effect Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000011109 contamination Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- 238000012958 reprocessing Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T7/00—Details of radiation-measuring instruments
- G01T7/02—Collecting means for receiving or storing samples to be investigated and possibly directly transporting the samples to the measuring arrangement; particularly for investigating radioactive fluids
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- High Energy & Nuclear Physics (AREA)
- Molecular Biology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Measurement Of Radiation (AREA)
- Sampling And Sample Adjustment (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Description
【発明の詳細な説明】
本発明は、特に再処理設備における処理液のプ
ルトニウム濃度を求めるためのアルフア線モニタ
線に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention particularly relates to an alpha radiation monitor line for determining the plutonium concentration of a processing liquid in a reprocessing facility.
この種のモニタで、測定液が測定セル内で検出
器に通じかつ検出器をおおう箔により閉鎖された
開口の近くを案内されるものは文献「ニユークリ
ア・インスツルメンツ・アンド・メソツズ
（Nuclear Instruments and Methods）」74（1969
年）第351−352頁により知られている。 Monitors of this type, in which the measuring liquid is guided in the measuring cell near an opening that leads to the detector and is closed by a foil covering the detector, are described in the document Nuclear Instruments and Methods. )” 74 (1969
2000), pages 351-352.
再処理設備における処理液のα放射能からその
プルトニウム濃度を非常に正確に求めることがで
きる。なぜならば、プルトニウムよりも原子番号
の大きい超ウラン元素のような他のα線放射物質
は既に最初の抽出段階において200〜1000の除染
係数で分離されるからである。また、プルトニウ
ムにくらべて、処理液のなかに同時に存在するウ
ランは10-5倍の小さいα放射能しか有していな
い。α線の到達距離は、物質との強い相互作用に
基づいて、液中で約0.05mm、空気中で約3.5cmに
とどまる。従つて、α放射能の測定に際しては、
液の薄い膜をα線検出器に極めて近接させる必要
がある。また、同時に存在するβおよびτ放射能
が検出器に影響するのを避ける必要がある。公知
のアルフア線モニタはこれらの必要条件を満たす
に至つていない。 The plutonium concentration of the treated liquid in the reprocessing facility can be determined very accurately from the alpha radioactivity. This is because other alpha-emitting substances, such as transuranic elements with higher atomic numbers than plutonium, are already separated in the first extraction stage with a decontamination factor of 200-1000. Furthermore, compared to plutonium, uranium, which is also present in the processing solution, has alpha radioactivity that is 10 -5 times smaller. Based on the strong interaction with substances, the alpha rays can reach approximately 0.05 mm in liquid and approximately 3.5 cm in air. Therefore, when measuring alpha radioactivity,
The thin film of liquid must be brought very close to the alpha detector. It is also necessary to avoid the simultaneous presence of β and τ radioactivity from affecting the detector. Known alpha line monitors fall short of meeting these requirements.
本発明の目的は、冒頭に記載した種類のアルフ
ア線モニタにおいて、バツクグラウンド放射線の
測定および感度校正を正確に行ない得るものを提
供することである。 The object of the invention is to provide an alpha radiation monitor of the type mentioned at the outset, with which background radiation measurement and sensitivity calibration can be carried out accurately.
この目的は本発明によれば、特許請求の範囲第
１項に記載のアルフア線モニタにより達成され
る。本発明の有利な実施態様は特許請求の範囲第
２項にあげられている。 This object is achieved according to the invention by an alpha line monitor according to claim 1. Advantageous embodiments of the invention are listed in claim 2.
本発明の特に有利な点は、検出器保護箔および
校正試料上の凝結がヘリウムガスの洗浄により防
止されることである。ガス洗浄は約４／ｈの小
さな流量で行なわれれば十分である。底に流出口
を有する切頭円錐状に槽を構成することにより、
15mlの洗浄過程を３回繰り返せば、再現可能なバ
ツクグラウンド（零位）計数率が得られる。校正
試料はごく少量のプルトニウムが融かし込まれて
いるガラス玉から成る。それにより、液からのエ
ネルギー分布と類似したエネルギー分布を持ち、
しかも化学的に最良の耐性を持つ試料が得られ
る。校正試料に対する計数率は測定液に対する計
数率の範囲内で感度の変動に比例した値となるの
で、バツクグラウンド放射線の測定の後に校正試
料を挿入することにより、いつでも測定の正しさ
をチエツクすることができる。バツクグラウンド
および感度の補正を行なつた上で記録計用の出力
を生ずる適当な計数率計を用いれば、記録計上に
処理液の連続監視のための測定値を得ることがで
きる。洗浄ガスとしてヘリウムを使用することに
より、感度が3.5倍に高められる。 A particular advantage of the invention is that condensation on the detector protection foil and the calibration sample is prevented by the helium gas flush. It is sufficient for gas cleaning to be carried out at a small flow rate of approximately 4/h. By configuring the tank in the shape of a truncated cone with an outlet at the bottom,
A reproducible background (zero) count rate can be obtained by repeating the 15 ml washing process three times. The calibration sample consists of a glass bead into which a small amount of plutonium is molten. As a result, it has an energy distribution similar to that from the liquid,
Moreover, samples with the best chemical resistance can be obtained. The counting rate for the calibration sample is a value proportional to the variation in sensitivity within the range of the counting rate for the measurement solution, so you can check the accuracy of the measurement at any time by inserting the calibration sample after measuring background radiation. Can be done. Measurements for continuous monitoring of the process liquid can be obtained on the recorder by using a suitable count rate meter that provides an output for the recorder after background and sensitivity corrections. By using helium as a cleaning gas, the sensitivity is increased by a factor of 3.5.
以下、本発明を実施例について図面により一層
詳細に説明する。 DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to the drawings with reference to embodiments.
図面には、主として槽１と蓋７と石英ドラム３
とこのドラムの頂点の上側に位置する半導体検出
器５とから成る測定セル２が断面図で示されてい
る。槽１は流入口９および流出口１０を経て測定
液または放射能のない液８で所定のレベルまで満
たすことができる。石英ドラム３は矢印方向に回
転し、その表面１１に液の膜を形成して、検出器
５の前方の開口１２の下側近くを通過する。この
膜から発せられるα線が検出器５により検出さ
れ、他方測定液８から発せられるα線およびβ線
はドラム３により直線遮蔽される。検出器５の下
側には汚染除去環１３が設けられており、また検
出器５自体は薄いPVC箔１４により直接汚染か
ら保護される。検出器５は保持体１５を介して開
口１２の上側で測定セル２の蓋７に取付けられて
いる。 The drawing mainly shows tank 1, lid 7, and quartz drum 3.
A measuring cell 2 is shown in cross-section, consisting of a semiconductor detector 5 and a semiconductor detector 5 located above the apex of this drum. The tank 1 can be filled to a predetermined level with a measuring liquid or a radioactive-free liquid 8 via an inlet 9 and an outlet 10. The quartz drum 3 rotates in the direction of the arrow, forms a liquid film on its surface 11, and passes near the bottom of the opening 12 in front of the detector 5. The α-rays emitted from this membrane are detected by the detector 5, while the α-rays and β-rays emitted from the measurement liquid 8 are linearly blocked by the drum 3. A decontamination ring 13 is provided on the underside of the detector 5, and the detector 5 itself is protected from direct contamination by a thin PVC foil 14. The detector 5 is attached via a holder 15 to the lid 7 of the measuring cell 2 above the opening 12 .
測定中、検出器５の保護箔１４の付近に洗浄ガ
スとしてヘリウムガスが側部の孔６を通して検出
器の前方に吹込まれ、それにより箔１４への液の
凝結が防止される。洗浄ガスは流出口１６を通つ
て槽１から流出する。 During the measurement, helium gas is blown into the vicinity of the protective foil 14 of the detector 5 as a cleaning gas in front of the detector through the side holes 6, thereby preventing liquid condensation on the foil 14. The cleaning gas leaves the tank 1 through the outlet 16.
感度校正のため校正試料４が用いられ、これは
孔６を通して検出器５の前方に挿入される。その
ために、均等に分布したプルトニウムを含むガラ
ス玉の形態の校正試料４がロツド１７の先端に取
付けられており、たとえば空気圧により軸線（両
方向矢印）方向に移動し得るようになつている。
測定の際、試料は孔６の内部に位置し、検出器に
対して遮蔽されている。 A calibration sample 4 is used for sensitivity calibration and is inserted in front of the detector 5 through the hole 6. For this purpose, a calibration sample 4 in the form of a glass bead containing evenly distributed plutonium is attached to the tip of the rod 17 and can be moved in the axial direction (double arrow), for example by means of air pressure.
During the measurement, the sample is located inside the hole 6 and is shielded from the detector.
バツクグラウンド放射線を求めるため、測定液
８が槽１から排出され、槽１およびドラム３がα
放射能のない有機液で３回繰り返して洗浄により
汚染除去される。この汚染除去の後に、セル２か
らの全残留放射線（バツクグラウンド）が検出器
５により検出される。 To determine the background radiation, the measuring liquid 8 is drained from the tank 1, and the tank 1 and the drum 3 are
It is decontaminated by washing three times with a radioactive-free organic solution. After this decontamination, all residual radiation (background) from the cell 2 is detected by the detector 5.
図面は本発明の実施例の断面図である。
１……槽、２……測定セル、３……ドラム、４
……校正プレパラート、５……検出器、６……
孔、７……蓋、８……液、９……流入口、１０…
…流出口、１１……ドラム表面、１２……開口、
１３……汚染除去環、１４……検出器保護箔、１
５……保持体、１６……洗浄ガス流出口、１７…
…ロツド。
The drawings are cross-sectional views of embodiments of the invention. 1...tank, 2...measuring cell, 3...drum, 4
...Calibration preparation, 5...Detector, 6...
Hole, 7...lid, 8...liquid, 9...inlet, 10...
...Outlet, 11...Drum surface, 12...Opening,
13... Contamination removal ring, 14... Detector protection foil, 1
5...Holding body, 16...Cleaning gas outlet, 17...
...Rotsud.
Claims (1)
が入れられ、該槽１のなかに、検出器５に通じか
つ該検出器をおおう箔１４で閉鎖された開口１２
の下側で回転して測定液の膜をアルフア線測定の
ため形成するドラム３が設けられ、前記開口１２
の側部に前記箔１４への液の凝結を保護する洗浄
ガスを導入するための孔６が設けられ、均等に分
布したプルトニウムを含むガラス玉から成る校正
試料４が前記洗浄ガス導入孔６を介して前記ドラ
ム３と前記箔４の間に挿入可能に配置されること
を特徴とするアルフア線モニタ。 ２ 洗浄ガスとしてヘリウムが用いられることを
特徴とする特許請求の範囲第１項記載のアルフア
線モニタ。[Claims] 1. A measurement liquid 8 is placed in a part of the tank 1 constituting the measurement cell 2.
is placed in the vessel 1, and in the vessel 1 there is an opening 12 leading to the detector 5 and closed with a foil 14 covering the detector.
A drum 3 is provided which rotates under the opening 12 to form a film of the measuring liquid for alpha radiation measurement.
A hole 6 for introducing a cleaning gas to protect the liquid from condensation on the foil 14 is provided on the side of the foil 14, and a calibration sample 4 made of glass beads containing evenly distributed plutonium is inserted through the cleaning gas introduction hole 6. An alpha line monitor characterized in that it is arranged so as to be insertable between the drum 3 and the foil 4 via the drum 3 and the foil 4. 2. The alpha line monitor according to claim 1, wherein helium is used as the cleaning gas.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19803017436 DE3017436A1 (en) | 1980-05-07 | 1980-05-07 | ALPHA MONITOR |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS574570A JPS574570A (en) | 1982-01-11 |
| JPH0145595B2 true JPH0145595B2 (en) | 1989-10-04 |
Family
ID=6101821
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6804681A Granted JPS574570A (en) | 1980-05-07 | 1981-05-06 | Alpha ray monitoring |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS574570A (en) |
| DE (1) | DE3017436A1 (en) |
| FR (1) | FR2482312A1 (en) |
| GB (1) | GB2077423B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0766076B2 (en) * | 1990-08-14 | 1995-07-19 | 動力炉・核燃料開発事業団 | Continuous heating denitration equipment by microwave |
| FR2684451B1 (en) * | 1991-11-29 | 1994-02-04 | Matieres Nucleaires Cie Gle | APPARATUS FOR MEASURING THE ALPHA ACTIVITY OF A SOLUTION. |
| FR2734647B1 (en) * | 1995-05-23 | 1997-07-04 | Cogema | TANK FOR ANALYSIS OF RADIOACTIVE LIQUIDS BY AN OVERLOADING DETECTOR |
| FR2815131B1 (en) * | 2000-10-06 | 2003-01-10 | Forschungszentrum Juelich Gmbh | METHOD AND DEVICE FOR MEASURING THE ACTIVITY OF AN ALPHA TRANSMITTER |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB876237A (en) * | 1958-06-17 | 1961-08-30 | Plessey Co Ltd | Improvements in or relating to equipment for monitoring radioactivity in liquids |
| GB984240A (en) * | 1962-05-10 | 1965-02-24 | Atomic Energy Authority Uk | Improvements in or relating to radiation monitors |
| GB989647A (en) * | 1962-06-27 | 1965-04-22 | Atomic Energy Authority Uk | Improvements in or relating to gamma radiation monitors |
-
1980
- 1980-05-07 DE DE19803017436 patent/DE3017436A1/en active Granted
- 1980-12-29 FR FR8027712A patent/FR2482312A1/en active Granted
-
1981
- 1981-04-07 GB GB8110919A patent/GB2077423B/en not_active Expired
- 1981-05-06 JP JP6804681A patent/JPS574570A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| DE3017436A1 (en) | 1981-11-12 |
| GB2077423B (en) | 1984-05-31 |
| JPS574570A (en) | 1982-01-11 |
| FR2482312A1 (en) | 1981-11-13 |
| GB2077423A (en) | 1981-12-16 |
| DE3017436C2 (en) | 1987-09-03 |
| FR2482312B1 (en) | 1983-04-08 |
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