JP3012891B2 - Identification of waste drum contents by active neutron method - Google Patents
Identification of waste drum contents by active neutron methodInfo
- Publication number
- JP3012891B2 JP3012891B2 JP4037259A JP3725992A JP3012891B2 JP 3012891 B2 JP3012891 B2 JP 3012891B2 JP 4037259 A JP4037259 A JP 4037259A JP 3725992 A JP3725992 A JP 3725992A JP 3012891 B2 JP3012891 B2 JP 3012891B2
- Authority
- JP
- Japan
- Prior art keywords
- thermal neutron
- waste
- count rate
- neutron
- contents
- 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
Landscapes
- Analysing Materials By The Use Of Radiation (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は，放射性廃棄物を収容
した，いわゆる廃棄物ドラム缶の内容物を非破壊にて識
別する（内容物を同定する）方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for non-destructively identifying the contents of a so-called waste drum containing radioactive waste (identifying the contents).
【０００２】[0002]
【従来の技術】従来、廃棄物ドラム缶中における内容物
の種類確認は，廃棄物をドラム缶に収容する際の記録に
よるか，廃棄物ドラム缶を開放するか，あるいは，分析
容器内に配置したパルス状中性子発生源より発生した高
速中性子が中性子減速材により減速されて生ずる分析容
器内の熱中性子束強度を測定する（例えば，特開平２−
２３８３５０号）ことによって行われた。2. Description of the Related Art Conventionally, the type of contents in a waste drum can be confirmed by recording the waste in a drum, by opening the waste drum, or by a pulse-like method arranged in an analysis container. fast neutrons generated from the neutron generator to measure the thermal neutron flux intensity in the analysis vessel caused is decelerated by the neutron moderating material (e.g., JP-2-
No. 238350 ).
【０００３】[0003]
【発明が解決しようとする課題】上記のような方法によ
り廃棄物ドラム缶中の内容物の種類の確認を行う場合，
記録による確認では誤記，取違い，記録の紛失等のトラ
ブルを生じる可能性があり，また，廃棄物ドラム缶を開
放する破壊検査を行った場合は，事後の除染作業から生
ずる新たな廃棄物とそれを処理するための作業量の増加
を招く。また，分析容器内の熱中性子束強度を測定して
行う場合，強度のわずかな変化が内容物の種類の大幅な
変化に対応することになり易く，同定性が悪い。When the type of the contents in the waste drum can is confirmed by the above-described method,
Confirmation by records may cause troubles such as clerical errors, mistakes, and loss of records. In addition, if destructive inspection is performed to open waste drums, new waste resulting from subsequent decontamination work may be added. This leads to an increase in the amount of work for processing it. Further, when measuring the thermal neutron flux intensity in the analysis container, a slight change in the intensity tends to correspond to a large change in the type of the content, and the identification property is poor.
【０００４】この発明は，このような事情に鑑みてなさ
れたものであり，廃棄物ドラム缶中の内容物の種類を非
破壊で精度よく判別する方法を提供することを目的とし
ている。The present invention has been made in view of such circumstances, and has as its object to provide a method for non-destructively and accurately discriminating the type of contents in a waste drum.
【０００５】[0005]
【課題を解決するための手段】前記の目的を達成するた
め，この発明では，核燃料サイクル施設より生ずる廃棄
物の種類を判別するに際して，アクティブ中性子法によ
り，被検査体である廃棄物ドラム缶へパルス状中性子発
生源より発生した高速中性子を照射し，該廃棄物ドラム
缶を収納する分析容器の壁を構成する中性子減速材およ
び廃棄物ドラム缶中の中性子減速材等により減速させ
る。減速された中性子束を分析容器壁表面から内部の種
々の距離に配置した熱中性子検出器で計測する。In order to attain the above object, according to the present invention, when discriminating the type of waste generated from a nuclear fuel cycle facility, a pulse is applied to a waste drum as a test object by an active neutron method. The neutrons are irradiated with high-speed neutrons generated from the source of neutrons, and the neutrons are decelerated by a neutron moderator constituting the wall of the analysis container accommodating the waste drum and a neutron moderator in the waste drum. The decelerated neutron flux is measured by a thermal neutron detector arranged at various distances from the surface of the analysis vessel wall to the interior.
【０００６】このようなアクティブ中性子法により廃棄
物ドラム缶中の種類を非破壊の状態で判別するものであ
る。The type in the waste drum can is determined in a non-destructive state by such an active neutron method.
【０００７】[0007]
【作用】この発明のアクティブ中性子法による廃棄物ド
ラム缶中の内容物の同定法は，同一の中性子発生条件の
ときには分析装置内部および分析容器壁内部の中性子の
エネルギ−スペクトルと廃棄物ドラム缶中の内容物の種
類との間には密接な関係があることを利用して，壁表面
から内部の種々の距離に配置した熱中性子検出器の熱中
性子計数率の計測結果と廃棄物ドラム缶中の内容物の重
量とによりそのドラム缶中の内容物を同定する。The method for identifying contents in a waste drum by the active neutron method according to the present invention is based on the following method. Utilizing the fact that there is a close relationship with the type of material, the measurement results of the thermal neutron count rate of thermal neutron detectors placed at various distances inside from the wall surface and the contents in waste drums And the weight of the drum identifies the contents in the drum.
【０００８】[0008]
【実施例】図１は，この発明において使用する装置の概
略図であり，１は中性子発生器（中性子発生管）でパル
ス状に高速中性子を発生する。２は分析容器で中性子減
速材（例えば，黒鉛）により作られ，中性子発生器１の
周囲を取り巻いており，中性子発生器１からの高速中性
子を減速することにより前記容器内に配置される廃棄物
ドラム缶３に減速中性子が照射される。４は熱中性子検
出器で，分析容器２の壁表面から種々の距離に配置さ
れ，更に，５は水ジャケットのような中性子の遮蔽体で
あるが，これは装置周辺の放射線防護のために設けられ
る生体遮蔽であり，必要に応じて設けられるものであ
る。６は秤を備えた廃棄物ドラム缶置台である。FIG. 1 is a schematic view of an apparatus used in the present invention. In FIG. 1, a neutron generator (neutron generating tube) generates fast neutrons in a pulse form. Reference numeral 2 denotes an analysis vessel, which is made of a neutron moderator (eg, graphite), surrounds the neutron generator 1, and is disposed in the vessel by decelerating fast neutrons from the neutron generator 1. The drum 3 is irradiated with deceleration neutrons. Numeral 4 is a thermal neutron detector, which is arranged at various distances from the wall surface of the analysis vessel 2. Numeral 5 is a neutron shield such as a water jacket, which is provided for radiation protection around the apparatus. The living body shield is provided as needed. Reference numeral 6 denotes a waste drum can table provided with a scale.
【０００９】廃棄物ドラム缶３中の内容物の同定は，上
記のような装置を用いて行われる。先ず，中性子発生器
１を作動して高速中性子を発生する。発生した高速中性
子は分析容器２の黒鉛減速材および廃棄物ドラム缶３中
の廃棄物に含まれる減速材によって減速され，熱中性子
と熱外中性子を主体とする中性子のエネルギ−・スペク
トルが形成される。これらの中性子の量を分析容器２の
壁表面から種々の距離に設置されている熱中性子検出器
４により計測し，各検出器の計数率と各検出器間の計数
率の比を求める。と同時に廃棄物ドラム缶３の重量をド
ラム缶置台６の秤により測定し，ドラム缶の自重を差引
いて内容物の重量を算出する。内容物の重量および熱中
性子計数率と各検出器間の熱中性子計数率比の計測結果
を，予め取得しているデ−タ（図３参照）と比較するこ
とにより，内容物の重量が同一の場合は，熱中性子計数
率および各検出器間の熱中性子計数率比より，また，同
一の熱中性子計数率および熱中性子計数率比の場合は，
内容物の重量より廃棄物の種類を判定できる。The identification of the contents in the waste drum 3 is performed using the above-described apparatus. First, the neutron generator 1 is operated to generate fast neutrons. The generated fast neutrons are slowed down by the graphite moderator in the analysis vessel 2 and the moderator contained in the waste in the waste drum 3 to form an energy spectrum of neutrons mainly composed of thermal neutrons and epithermal neutrons. . The amounts of these neutrons are measured by the thermal neutron detectors 4 installed at various distances from the wall surface of the analysis vessel 2, and the ratio between the count rate of each detector and the count rate between the detectors is determined. At the same time, the weight of the waste drum 3 is measured by the scale of the drum mounting table 6, and the weight of the contents is calculated by subtracting the weight of the drum. By comparing the weight of the contents and the measurement result of the thermal neutron count rate and the ratio of the thermal neutron count rates between the detectors with data obtained in advance (see FIG. 3), the weight of the contents is the same. In the case of, the thermal neutron count rate and the thermal neutron count rate ratio between each detector, and for the same thermal neutron count rate and thermal neutron count rate ratio,
The type of waste can be determined from the weight of the contents.
【００１０】尚，図３は，廃棄物ドラム缶３中の内容物
の種類・重量と分析容器２の壁内の熱中性子計数率およ
び各検出器間の熱中性子計数率との比との関係（高速中
性子照射条件：１×１０8 ｎ／秒）を示しており，同図
から分かるように，内容物の重量が同一の場合はその種
類により熱中性子計数率は異なっている。また，同一の
内容物でも分析容器壁内の検出器の位置によって熱中性
子計数率は異なっている。鉄パイプと塩化ビニ−ルとは
分析容器内の熱中性子計数率では同定が困難であるが，
図３から明らかなように，分析容器壁内の熱中性子計数
率と分析容器壁内の各検出器間の熱中性子計数率の比か
ら同定できる。FIG. 3 shows the relationship between the type and weight of the contents in the waste drum 3 and the ratio of the thermal neutron count rate in the wall of the analysis container 2 and the thermal neutron count rate between the detectors ( Fast neutron irradiation conditions: 1 × 10 8 n / sec). As can be seen from the figure, when the contents have the same weight, the thermal neutron counting rate differs depending on the type. Also, the thermal neutron counting rate differs depending on the position of the detector in the wall of the analysis container even for the same contents. It is difficult to identify iron pipe and vinyl chloride based on the thermal neutron count rate in the analytical vessel.
As can be seen from FIG. 3, it can be identified from the ratio between the thermal neutron count rate in the analysis vessel wall and the thermal neutron count rate between the detectors in the analysis vessel wall.
【００１１】[0011]
【発明の効果】以上の説明から明らかなように，この発
明によれば廃棄物ドラム缶中の内容物を非破壊で判別
（同定）することができ，廃棄物ドラム缶中の廃棄物の
種類に関する記録を再確認することができる。また，記
録等によっては内容物の種類が不明な廃棄物ドラム缶に
対してもその内容物の種類を把握することが可能とな
る。As is apparent from the above description, according to the present invention, the contents in the waste drum can be discriminated (identified) in a non-destructive manner, and the record on the type of the waste in the waste drum can is obtained. Can be reconfirmed. In addition, the type of the contents can be grasped even for a waste drum can whose type is unknown depending on records or the like.
【図１】本発明において使用する装置の説明図である。FIG. 1 is an explanatory diagram of an apparatus used in the present invention.
【図２】分析容器壁内に配置された熱中性子検出器の配
置例を示す図であり，図１におけるＡ−Ａ部断面を示す
図である。FIG. 2 is a diagram showing an arrangement example of a thermal neutron detector arranged in an analysis container wall, and is a diagram showing a cross section taken along the line AA in FIG. 1;
【図３】廃棄物ドラム缶中の内容物の種類・重量と分析
容器の壁内の熱中性子計数率と壁内各検出器間の熱中性
子計数率との比との関係を示す図である。FIG. 3 is a diagram showing the relationship between the type and weight of contents in a waste drum and the ratio of the thermal neutron count rate in the wall of the analysis container to the thermal neutron count rate between detectors in the wall.
１ 中性子発生器 ２ 分析容器 ３ 廃棄物ドラム缶 ４ 熱中性子検出器 ５ 遮蔽体 ６ 廃棄物ドラム缶置台（秤） Reference Signs List 1 neutron generator 2 analysis container 3 waste drum 4 thermal neutron detector 5 shield 6 waste drum can (weigher)
───────────────────────────────────────────────────── フロントページの続き (72)発明者 舘野 徹 東京都港区芝公園２−４−１ 三菱原子 力工業株式会社内 (56)参考文献 特開 平２−238350（ＪＰ，Ａ) 特開 平１−244345（ＪＰ，Ａ) 特開 平１−140051（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 23/00 - 23/227 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toru Tateno 2-4-1 Shiba Park, Minato-ku, Tokyo Inside Mitsubishi Nuclear Power Industry Co., Ltd. (56) References JP-A-2-238350 (JP, A) JP-A JP-A-1-244345 (JP, A) JP-A-1-140051 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) G01N 23/00-23/227
Claims (1)
器および廃棄物ドラム缶を配置し，また，前記分析容器
壁内に複数の熱中性子検出器を配置し，前記中性子発生
器にて高速中性子を発生させ，これを減速して前記廃棄
物ドラム缶に照射するとともに， ａ．前記熱中性子検出器にて前記分析容器壁内の熱中性
子計数率を計測するステップ，ｂ．いくつかの熱中性子検出器間の熱中性子計数率比を
求めるステップ， ｃ ．前記廃棄物ドラム缶の内容物の重量を求めるステッ
プ，ｄ ．前記ステップａと同一の高速中性子照射条件下にて
予め求めた廃棄物種別・重量別の分析容器壁内の熱中性
子計数率を用い，前記ステップａにて計測した熱中性子
計数率，前記ステップｂにて計測した熱中性子計数率比
および前記ステップｃにて計測した廃棄物重量からその
内容物を判定するステップ，とを包含し、前記熱中性子
検出器は，壁表面から種々の深さの位置に複数配置され
ており、壁表面からの深さが相互に異なることにより熱
外中性子に対するエネルギー感度がそれぞれ異なること
を特徴とするアクティブ中性子法による廃棄物ドラム缶
内容物の同定法。1. A neutron generator and a waste drum can are arranged in an analysis vessel made of a moderator, and a plurality of thermal neutron detectors are arranged in the analysis vessel wall. And irradiates the waste drum at a reduced speed with a. Measuring the thermal neutron count rate in the analysis vessel wall with the thermal neutron detector; b. The thermal neutron count rate ratio between several thermal neutron detectors
Seeking step, c . Determining the weight of the contents of said waste drum, d . Previously determined waste thermal neutron count rate using a type and weight Analysis by vessel wall, thermal neutron count rate measured in step a at the same fast neutron irradiation conditions with said step a, step b determining its content from waste weight measured by the measured thermal neutron count rate ratio <br/> and the step c at encompasses capital, the thermal neutron
Multiple detectors are placed at various depths from the wall surface.
Heat at different depths from the wall surface
Different energy sensitivities to outer neutrons
A method for identifying the contents of waste drums by the active neutron method characterized by the following.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4037259A JP3012891B2 (en) | 1992-01-28 | 1992-01-28 | Identification of waste drum contents by active neutron method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4037259A JP3012891B2 (en) | 1992-01-28 | 1992-01-28 | Identification of waste drum contents by active neutron method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05281158A JPH05281158A (en) | 1993-10-29 |
| JP3012891B2 true JP3012891B2 (en) | 2000-02-28 |
Family
ID=12492663
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4037259A Expired - Lifetime JP3012891B2 (en) | 1992-01-28 | 1992-01-28 | Identification of waste drum contents by active neutron method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3012891B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2764383B1 (en) * | 1997-06-06 | 1999-07-23 | Commissariat Energie Atomique | METHOD AND DEVICE FOR MEASURING THE RELATIVE PROPORTION OF PLUTONIUM AND URANIUM IN A BODY |
| JP2007218663A (en) * | 2006-02-15 | 2007-08-30 | Japan Atomic Energy Agency | Device and method for searching for existing location of fissionable material in radioactive waste |
| JP5404143B2 (en) * | 2009-04-07 | 2014-01-29 | 株式会社東芝 | Nondestructive inspection method and nondestructive inspection device for sealed container |
| CN103454669B (en) * | 2012-05-28 | 2015-08-19 | 中国原子能科学研究院 | The scale method of barreled nuclear waste neutron measurement device |
-
1992
- 1992-01-28 JP JP4037259A patent/JP3012891B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05281158A (en) | 1993-10-29 |
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