JPH0351788A - Method and apparatus for measuring radioactivity - Google Patents

Method and apparatus for measuring radioactivity

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Publication number
JPH0351788A
JPH0351788A JP1184650A JP18465089A JPH0351788A JP H0351788 A JPH0351788 A JP H0351788A JP 1184650 A JP1184650 A JP 1184650A JP 18465089 A JP18465089 A JP 18465089A JP H0351788 A JPH0351788 A JP H0351788A
Authority
JP
Japan
Prior art keywords
concrete
tritium
water
measured
recovered
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
JP1184650A
Other languages
Japanese (ja)
Inventor
Tatsuo Izumida
龍男 泉田
Tsutomu Baba
務 馬場
Koichi Chino
耕一 千野
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP1184650A priority Critical patent/JPH0351788A/en
Publication of JPH0351788A publication Critical patent/JPH0351788A/en
Pending legal-status Critical Current

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  • Measurement Of Radiation (AREA)

Abstract

PURPOSE:To accurately measure the concn. of tritium by evaporating the moisture in an inorg. material under heating and recovering the evaporated steam under cooling while measuring the radioactivity of the aforementioned recovered water. CONSTITUTION:A sample to be measured is sampled from concrete containing tritium by a concrete sampling and wt. measuring apparatus 1 and the wt. thereof is also measured. The concrete sample 5 is heated in a concrete evaporating and heating apparatus 2 to entirely evaporate the moisture in the sample and the evaporated steam 6 is cooled and recovered as water in the evaporated steam recovery apparatus 3. The recovered water 7 is supplied to a tritium measuring apparatus 4 and the amount of tritium in the recovered water 7 is measured. The steam generated from the concrete evaporating and heating apparatus 2 is returned to water by the evaporated steam recovery apparatus 3. By using the moisture recovered herein, beta-rays from tritium is accurately measured by the tritium measuring apparatus of the next process.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、原子力発電所等から発生する放射性コンクリ
ート中の放射能の測定方法に関する。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for measuring radioactivity in radioactive concrete generated from nuclear power plants and the like.

〔従来の技術〕[Conventional technology]

原子力発電所等の建屋、及び、放射線のしゃへい材はコ
ンクリートで構成されており、これらは原子炉から放射
される中性子によって少なからず放射化されている。す
なわち、コンクリートを構成している原子が中性子との
核反応によって、その一部が放射性物質に変換される。
The buildings of nuclear power plants and other facilities and radiation shielding materials are made of concrete, and these are activated to a large extent by neutrons emitted from nuclear reactors. In other words, some of the atoms that make up concrete are converted into radioactive substances through nuclear reactions with neutrons.

コンクリートを構成する物質は、水とケイ酸カルシウム
が大部分であるが、放射化によって生成する放射性核種
は、水の中の水素から生成するトリチウムが大部分であ
る。具体的には、照射される中性子のエネルギによって
生成量は異なるが、放射性核種の中でトリチウムは70
〜80%を占める。このトリチウムを主体とした放射化
コンクリートは1発電所を廃止、さらには、解体した場
合、大量に発生することとなる。この廃棄物の処分方法
は、廃棄物中の放射能量に応じて選別分類され、場合に
よっては放射能量が通常環境中のものと同一であれば、
非放射性として一般廃材扱いすることも可能である。従
って、このコンクリート廃材中の放射能量の測定は必須
技術となっている。
Most of the substances that make up concrete are water and calcium silicate, but most of the radionuclides produced by activation are tritium, which is produced from hydrogen in water. Specifically, the amount produced varies depending on the energy of the irradiated neutrons, but tritium accounts for 70% of the radionuclides.
It accounts for ~80%. A large amount of this tritium-based radioactive concrete will be generated if a power plant is shut down or even demolished. This waste disposal method is sorted and classified according to the amount of radioactivity in the waste, and in some cases, if the amount of radioactivity is the same as that in the environment,
It is also possible to treat it as general waste as it is non-radioactive. Therefore, measuring the amount of radioactivity in this concrete waste has become an essential technology.

コンクリート廃材中の放射能の大部分を占めるトリチウ
ムは、純β線放出核種であり1通常はアイソトープ便覧
(日本アイソトープ協会編) P439に示されるよう
な液体シンチレーションカウンタが最も良は計測法とい
われている。これは測定試料をシンチレータを含む水溶
液中に溶解して計測するものであり、コンクリートに、
直接、適用するのは困難である。また、放射線計測法と
して。
Tritium, which accounts for most of the radioactivity in concrete waste, is a pure β-ray emitting nuclide.1The best measurement method is usually a liquid scintillation counter as shown in Isotope Handbook (edited by the Japan Isotope Association), page 439. There is. In this method, the measurement sample is dissolved in an aqueous solution containing a scintillator.
It is difficult to apply directly. Also, as a radiation measurement method.

他のGe、NaI等の固体シンチレータも、以下に述べ
る理由で適用は困難である。
Other solid scintillators such as Ge and NaI are also difficult to apply for the reasons described below.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

コンクリート中に存在するトリチウムは、放射線として
β線を放出するが、このβ線は固体中では飛程が短かい
ため、固体内部で放出されたβ線のほとんどは内部で減
衰消滅し、表面からは出てこない。従って、コンクリー
ト表面から出てくるトリチウムからのβ線は、表面上に
存在するトリチウムのみからであり、内部に存在するト
リチウムを放射線計測によって検知するのは本質的に不
可能である。従って、NaI、Ge等の固体の検出器で
は、コンクリート内部のトリチウムを検出できない。
Tritium present in concrete emits beta rays as radiation, but since the range of these beta rays is short in solids, most of the beta rays emitted inside the solid attenuate and annihilate, leaving the surface. does not appear. Therefore, the beta rays from tritium emitted from the concrete surface are only from the tritium present on the surface, and it is essentially impossible to detect the tritium present inside by radiation measurement. Therefore, solid state detectors such as NaI and Ge cannot detect tritium inside concrete.

本発明の目的は、この問題に対し、コンクリート内部の
トリチウムの検出を可能とすることにある。
An object of the present invention is to solve this problem by making it possible to detect tritium inside concrete.

〔課題を解決するための手段〕[Means to solve the problem]

上記目的を達成するためには、コンクリート内部のトリ
チウムを何らかの方法で回収し、これを液体シンチレー
ションカウンタで計測するのが最も効果的である。コン
クリート中のトリチウムは、そのすべてが水として存在
すると考えてよい。なんとなれば、コンクリート試料の
一部を強制的に加熱す、ることで、水分を蒸発させ、そ
の蒸発水を冷却回収することで、コンクリート内部のト
リチウム全量を取扱いの容易な水の形態で回収でき、か
つ、容易に液体シンチレーションカウンタで計測可能で
ある。液体シンチレーションカウンタは。
In order to achieve the above objective, it is most effective to collect tritium inside concrete by some method and measure it with a liquid scintillation counter. It can be assumed that all of the tritium in concrete exists as water. By forcibly heating a part of the concrete sample, the water is evaporated, and by cooling and recovering the evaporated water, the entire amount of tritium inside the concrete can be recovered in the form of water, which is easy to handle. and can be easily measured using a liquid scintillation counter. liquid scintillation counter.

β線を吸収して発光する物質(シンチレータ)を含む水
溶液中に試料溶液を溶かし、この試料から放出されるβ
線をシンチレータが吸収して、その際に発するシンチレ
ータからの発光を検知する。
The sample solution is dissolved in an aqueous solution containing a substance (scintillator) that absorbs β-rays and emits light, and the β-rays released from this sample are
A scintillator absorbs the radiation and detects the light emitted from the scintillator.

従って、計測効率が高く、精確なトリチウムの計測が可
能である。
Therefore, measurement efficiency is high and tritium can be measured accurately.

コンクリート中のトリチウムを含む水は、ゲル水と呼ば
れるコンクリートの構成粒子を間隙を埋めている水が、
もしくは、コンクリート粒子の構成物中の結晶水として
存在する。前者のゲル水は、温度200〜300℃で容
易に蒸発する。一方、後者の結晶水は、もっと高温にし
ないと蒸発しない。通常のコンクリートでは、1000
℃程度で全て蒸発することを実験的に確がめた。従って
、1000℃で試料片を加熱することで、コンクリート
中のトリチウムを含む水が蒸発し、これを冷却回収する
ことで、トリチウムを回収できる。また、この方法は、
コンクリートに限らず、他の無機材料でも同様に回収で
きる。
The tritium-containing water in concrete is called gel water, which is water that fills the gaps between the constituent particles of concrete.
Alternatively, it exists as water of crystallization in the composition of concrete particles. The former gel water easily evaporates at a temperature of 200 to 300°C. On the other hand, the latter crystal water does not evaporate unless it is heated to a much higher temperature. In normal concrete, 1000
It has been experimentally confirmed that all of it evaporates at about ℃. Therefore, by heating the sample piece at 1000° C., the water containing tritium in the concrete evaporates, and by cooling and collecting it, tritium can be recovered. Also, this method
Not only concrete, but also other inorganic materials can be recovered in the same way.

〔作用〕[Effect]

本発明では、まず、コンクリート試料を1000℃まで
加熱することで、その内部に含まれるトリチウムを含む
水分とすべて蒸発させ1次に、その蒸発水を冷却回収し
、その回収水を液体シンチレータで計測することにより
、コンクリート中のトリチウム濃度を正確に測定するこ
とができる。
In the present invention, first, by heating a concrete sample to 1000 degrees Celsius, all the water containing tritium contained within it is evaporated.Then, the evaporated water is cooled and collected, and the collected water is measured with a liquid scintillator. By doing so, it is possible to accurately measure the tritium concentration in concrete.

〔実施例〕〔Example〕

以下、本発明の一実施例を第1図により説明する。 An embodiment of the present invention will be described below with reference to FIG.

本発明の実施例の構成は、コンクリートサンプリング、
及び1重量計測装置1.コンクリート蒸発加熱装置2.
蒸発水回収装置3.トリチウム計測装置1E4から構成
される。まず、計測対象の放射化コンクリート等のトリ
チウムを含むコンクリートから、計測用試料゛をコンク
リートサンプリング。
The configuration of the embodiment of the present invention includes concrete sampling,
and 1 weight measuring device 1. Concrete evaporative heating device 2.
Evaporated water recovery device 3. It is composed of a tritium measuring device 1E4. First, concrete samples for measurement are taken from concrete containing tritium, such as radioactive concrete to be measured.

及び1重量測定装置1によりサンプリングし、かつ、重
量を計測する。このコンクリートサンプル5をコンクリ
ート蒸発加熱装置2で加熱し、サンプリング片内部の水
分を全て蒸発させ、この蒸発蒸気6を次工程の蒸発水回
収装置3で水として冷却回収する0回収した水7をトリ
チウム計測装置4で回収水7中のトリチウム量を計測す
る。以下に実施の際の詳細条件を記述する。
1. Sampling is performed using the weight measuring device 1, and the weight is measured. This concrete sample 5 is heated in a concrete evaporation heating device 2 to evaporate all the moisture inside the sample piece, and this evaporated vapor 6 is cooled and recovered as water in the evaporated water recovery device 3 in the next step.0 The recovered water 7 is converted into tritium. The measuring device 4 measures the amount of tritium in the recovered water 7. The detailed conditions for implementation are described below.

コンクリートサンプリング、及び、重量計測袋!!!1
でサンプリングするサンプリング片の大きさは、次工程
のコンクリート蒸発加熱装置2の処理容量に応じたもの
であれば良く、特に、制限はない。測定精度の向上の点
からは、大きければ大きいほど良いが、次工程の蒸発加
熱装置2の容量、及び、加熱時間が大きくなるという問
題がでてくる。従って、数十gから数−程度までが適当
である。
Concrete sampling and weighing bags! ! ! 1
The size of the sampling piece to be sampled is not particularly limited as long as it corresponds to the processing capacity of the concrete evaporation heating device 2 in the next step. From the point of view of improving measurement accuracy, the larger the value, the better, but this poses a problem in that the capacity of the evaporation heating device 2 in the next step and the heating time become longer. Therefore, it is appropriate to use from several tens of grams to several grams.

コンクリート蒸発加熱装置2での加熱は、温度1000
℃程度で、コンクリート内部の水分は全て蒸発するため
、この温度以上にするのが良い。
Heating with the concrete evaporation heating device 2 is performed at a temperature of 1000.
Since all the moisture inside the concrete evaporates at around ℃, it is best to keep the temperature above this temperature.

しかし、2000度以上になると、コンクリートの構成
物質の溶融、及び、蒸発が始まるため、これ以上は適当
でない。また、加熱時間は、加熱中の重量変化も計測で
きるようにしておけば、加熱初期の水分蒸発による重量
減少が把握でき、その減少がなくなった時点で加熱を停
止すればよい。
However, if the temperature exceeds 2000 degrees, the constituent materials of concrete begin to melt and evaporate, so it is not appropriate to exceed this temperature. In addition, if the heating time is set so that the weight change during heating can be measured, the weight loss due to water evaporation in the early stage of heating can be ascertained, and the heating can be stopped when the weight loss stops.

しかし、事前に水分蒸発量をコンクリート重量に対して
把握しておけば、加熱時の重量変化の測定は不要である
However, if the amount of water evaporation is known in advance relative to the concrete weight, there is no need to measure the weight change during heating.

コンクリート蒸発加熱装置2から発生する水蒸気は、蒸
発水回収装置3で水分にもどされる。これは通常の冷却
装置で実施される。ここで回収された水分により次工程
のトリチウム計測装置で、トリチウムからのβ線が計測
される。この計測装置は、液体シンチレーションカウン
タが最も効率よく、しかも、精度よく計測できる。しか
し、トリチウム濃度が充分高い場合は、NaI、Ge等
の固体シンチレータなどでも計測できる。また、計測時
は、マルチチャンネルの皮高分析器を使用すれば、トリ
チウム以外のC−141”P等も計測することができる
Water vapor generated from the concrete evaporative heating device 2 is converted back into moisture by the evaporative water recovery device 3. This is carried out with conventional cooling equipment. Using the water recovered here, β-rays from tritium are measured in a tritium measuring device in the next step. As for this measuring device, a liquid scintillation counter is the most efficient and can measure with high precision. However, if the tritium concentration is sufficiently high, it can be measured using a solid scintillator such as NaI or Ge. Furthermore, when measuring, if a multi-channel skin height analyzer is used, it is possible to measure C-141''P and the like other than tritium.

〔発明の効果〕〔Effect of the invention〕

本発明によれば、コンクリート中のトリチウムを蒸発加
熱により水分として分離回収することができるので、そ
の回収水の放射線計測により、コンクリート中のトリチ
ウム濃度を精度良く計測することができる。
According to the present invention, since tritium in concrete can be separated and recovered as water by evaporative heating, the tritium concentration in concrete can be measured with high accuracy by radiation measurement of the recovered water.

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

第1図は本発明の一実施例のブロック図である。 1・・・コンクリートサンプリング及び重量計測装置、
2・・・コンクリート蒸発加熱装置、3・・・蒸発水回
収装置、 4・・・トリチウム計測装置、 5・・・コンクリ− 七り 第 図
FIG. 1 is a block diagram of one embodiment of the present invention. 1... Concrete sampling and weight measurement device,
2... Concrete evaporation heating device, 3... Evaporated water recovery device, 4... Tritium measuring device, 5... Concrete seventh diagram

Claims (1)

【特許請求の範囲】 1、無機材料中に含まれるトリチウムを計測する方法に
おいて、 無機材料中の水分を加熱蒸発させ、蒸発した蒸気を冷却
回収した後に、前記回収水の放射能を計測することを特
徴とする放射能計測方法。 2、無機材料中の水分を加熱蒸発させる手段と、蒸発し
た蒸気を回収する手段と、前記回収水の放射能を計測す
る手段となる放射能計測装置。
[Claims] 1. In a method for measuring tritium contained in an inorganic material, water in the inorganic material is heated and evaporated, the evaporated vapor is cooled and collected, and then the radioactivity of the collected water is measured. A radioactivity measurement method characterized by: 2. A radioactivity measuring device that serves as a means for heating and evaporating moisture in an inorganic material, a means for recovering the evaporated steam, and a means for measuring the radioactivity of the recovered water.
JP1184650A 1989-07-19 1989-07-19 Method and apparatus for measuring radioactivity Pending JPH0351788A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1184650A JPH0351788A (en) 1989-07-19 1989-07-19 Method and apparatus for measuring radioactivity

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1184650A JPH0351788A (en) 1989-07-19 1989-07-19 Method and apparatus for measuring radioactivity

Publications (1)

Publication Number Publication Date
JPH0351788A true JPH0351788A (en) 1991-03-06

Family

ID=16156948

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1184650A Pending JPH0351788A (en) 1989-07-19 1989-07-19 Method and apparatus for measuring radioactivity

Country Status (1)

Country Link
JP (1) JPH0351788A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5382344A (en) * 1991-08-02 1995-01-17 Anelva Corporation Sputtering apparatus
US5458759A (en) * 1991-08-02 1995-10-17 Anelva Corporation Magnetron sputtering cathode apparatus
US6306267B1 (en) 1997-05-14 2001-10-23 Canon Kabushiki Kaisha Method of producing a photovoltaic device using a sputtering method
RU2624987C1 (en) * 2016-06-03 2017-07-11 Федеральное государственное унитарное предприятие "Всероссийский научно-исследовательский институт автоматики им. Н.Л. Духова" (ФГУП "ВНИИА") Method of measuring radioactivity of tritium target in sealed neutron tube

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5382344A (en) * 1991-08-02 1995-01-17 Anelva Corporation Sputtering apparatus
US5458759A (en) * 1991-08-02 1995-10-17 Anelva Corporation Magnetron sputtering cathode apparatus
US6306267B1 (en) 1997-05-14 2001-10-23 Canon Kabushiki Kaisha Method of producing a photovoltaic device using a sputtering method
RU2624987C1 (en) * 2016-06-03 2017-07-11 Федеральное государственное унитарное предприятие "Всероссийский научно-исследовательский институт автоматики им. Н.Л. Духова" (ФГУП "ВНИИА") Method of measuring radioactivity of tritium target in sealed neutron tube

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