JPH02251784A - Measuring method of radioactive concentration of wall surface - Google Patents
Measuring method of radioactive concentration of wall surfaceInfo
- Publication number
- JPH02251784A JPH02251784A JP1072638A JP7263889A JPH02251784A JP H02251784 A JPH02251784 A JP H02251784A JP 1072638 A JP1072638 A JP 1072638A JP 7263889 A JP7263889 A JP 7263889A JP H02251784 A JPH02251784 A JP H02251784A
- Authority
- JP
- Japan
- Prior art keywords
- wall surface
- measurement
- divided
- determined
- pole
- 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
Links
- 238000000034 method Methods 0.000 title claims description 16
- 230000002285 radioactive effect Effects 0.000 title abstract description 4
- 238000005259 measurement Methods 0.000 claims abstract description 24
- 238000001514 detection method Methods 0.000 claims abstract description 5
- 230000005855 radiation Effects 0.000 claims description 21
- 230000004907 flux Effects 0.000 claims description 12
- 238000010276 construction Methods 0.000 abstract 1
- 206010073306 Exposure to radiation Diseases 0.000 description 4
- 230000005251 gamma ray Effects 0.000 description 4
- 238000011109 contamination Methods 0.000 description 3
- 239000012857 radioactive material Substances 0.000 description 3
- 230000001066 destructive effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000003758 nuclear fuel Substances 0.000 description 2
- 239000000443 aerosol Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003028 elevating effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000007433 macroscopic evaluation Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
Landscapes
- Measurement Of Radiation (AREA)
Abstract
Description
［発明の目的］
（産業上の利用分野）
本発明は、原子力発電プラント等の核燃料あるいは放射
性物質取扱い施設における室内壁面（床、天井及び！り
の放射能濃度分布の評価に利用される壁面放射能濃度測
定方法に関する。
（従来の技術）
従来、原子力発電プラント等の核燃料あるいは放射性物
質取扱い施設において、建屋の壁面（床、天井及び壁）
の放射能含有量あるいは放射能汚染を測定する方法とし
ては、エリヤモニタによる方法、ダストサンプリングに
よるフィルタの放射線計測による方法、ＴＬＤ素子を用
いた被曝線量評価による方法、サーベイメータを用いた
表面サーベイによる方法あるいは壁面を破壊してサンプ
リングした試料の含有放射能量定量による方法等があげ
られる。
（発明が解決しようとする課ｇＡ）
しかしながら、上述した従来の方法では、次のような開
局がある。
すなわち、エリャモニ・りあるいはＴＬＤ素子を用いた
方法では、測定対象が壁面の場合には測定領域が狭い上
、得られる結果はその場所でのＩｌ量であり、コンクリ
ート等の壁材の含有放射能量を評価するのは困難である
。
また、ダストサンプラーを用いた方法では、当然の・こ
とながらエアロゾル成分しか評価できないため、他の方
法との併用が必要となる。
また、サーベイメータを用いての放射線管理作業風の表
面サーベイによる方法では、汚染箇所、レベルを同定で
きる利点はあるものの、膨大な労力、時間が必要となり
、また、作業員の被曝の可能性も生じる。
さらに、壁面の表面をはつり、そのはつり片を破壊分析
あるいは非破壊分析による手法は、そのはつり片の代表
性の問題がついてまわるのみならず、相当の時間と労力
とが必要となる。
本゛発明は、かかる従来の事情に対処してなされたもの
で、従来に較べて簡易かつ正確に壁面放射能濃度分布を
求めることができ、測定に要する労力と時間の大幅な削
減および作業員の被曝低減を図ることのできる壁面放射
能濃度測定方法を提供しようとするものである。[Purpose of the Invention] (Field of Industrial Application) The present invention is directed to the field of wall radiation used to evaluate the radioactivity concentration distribution on indoor walls (floors, ceilings, etc.) in facilities that handle nuclear fuel or radioactive materials such as nuclear power plants. Concerning a method for measuring energy concentration. (Conventional technology) Conventionally, in facilities handling nuclear fuel or radioactive materials such as nuclear power plants, the walls (floors, ceilings, and walls) of buildings
Methods for measuring radioactive content or radioactive contamination include area monitors, filter radiation measurements using dust sampling, exposure dose evaluation using TLD elements, and surface surveys using survey meters. Alternatively, there may be a method of quantifying the amount of radioactivity contained in a sample sampled by destroying the wall surface. (Issue gA to be solved by the invention) However, in the conventional method described above, the following openings occur. In other words, when the measurement target is a wall surface, the measurement area is narrow in the method using Ellamoni-Li or TLD elements, and the result obtained is the amount of Il at that location, and the amount of radioactivity contained in wall materials such as concrete. is difficult to evaluate. Furthermore, since the method using a dust sampler can only evaluate aerosol components, it must be used in combination with other methods. In addition, although surface surveys using survey meters, similar to radiation control work, have the advantage of being able to identify contamination locations and levels, they require a huge amount of labor and time, and also pose the possibility of worker exposure to radiation. . Furthermore, the method of chiseling the surface of a wall and performing destructive or non-destructive analysis of the chipped pieces not only involves problems with the representativeness of the chipped pieces, but also requires considerable time and effort. The present invention has been made in response to the above-mentioned conventional circumstances, and it is possible to obtain the wall surface radioactivity concentration distribution more easily and accurately than in the past, significantly reducing the labor and time required for measurement, and reducing the number of workers required. The purpose of the present invention is to provide a method for measuring wall surface radioactivity concentration that can reduce radiation exposure.
【発明の構成】
（ａｌｉｌを°解決するための手段）
すなわち、本発明の壁面放射能濃度測定方法は、測定対
象壁面に対応した空間中の複数点で放射線検出器により
放射線束を測定し、前記壁面に対する前記放射線束ｎ１
定位置の幾何学的な関係から求められる検出効率と前記
放射線検出器固有の計数効率との積として求められる計
数と、前記放射線束の測定結果とから前記壁面の放射能
濃度分布を求めることを特徴とする。
（作 用）
上記構成の本発明の壁面放射能濃度測定方法では、例え
ば車輪等を有し移動自在とされた基台上に設けられ、昇
降機構により上下動０在とされた放射線検出器等を用い
て、測定対象壁面に対応した空間中の複数点で放射線束
を測定する。
そして、壁面に対する放射線束測定位置の幾何学的な関
係から求められる検出効率と放射線検出器固有の計数効
率との積として求められる計数と、放射線束の測定結果
とから壁面の放射能濃度分布を求める。
したがって、従来に較べて簡易かつ正確に壁面放射能濃
度分布を求めることができ、測定に要する労力と時間の
大幅な削減および作業員の被曝低減を図ることができる
。
（実施例）
以下、本発明の一実施例の壁面放射能濃度測定方法を図
面を参照して説明する。
第１図は本発明の一実施例方法を実現するための壁面放
射能濃度測定装置の構成を示すもので、図において符号
１はγ線検出器を示している。
このγ線検出器１は、伸縮可能なポール２上に設けられ
ており、このポール２により所望の高さに固定可能に構
成されている。また、このポール２は、複数の車輪３を
備え床上を移動自在に構成された基台４上に固定されて
おり、この基台４を移動させ、ポール２を伸縮させるこ
とにより、γ線検出器１を建屋５内の所望の位置に設定
し、３次元的な放射線束分布を測定可能に構成されてい
る。
上記構成の壁面放射能濃度測定装置を用いて、この実施
例で゛は、次のようにして壁面放射能濃度測定を行う。
すなわち、第２図に示すように、測定を行う建ｊｉ５の
各壁面を仮想的に複数に分割し、この仮想分割数に応じ
て建屋内の幾何学的配置（構造）を考慮した上で必要と
される適当な測定位置で順次測定を重ね、各壁仮想分割
面からの規定位置への三次元的効率との関係から、壁面
の各仮想分割面単位での放射能濃度を求める。
すなわち、第２図に示した例では各壁面を４分割したも
のであるが、これらの２４の分割面に対する求める放射
能濃度を、それぞれＡｔ ＳＡ２ 、・・・ＡＩ・・・
、Ａ２４、また測定された値をＣＩ 、Ｃ２、・・・Ｃ
ｔ・・・ Ｃ２４とすると、ＡとＣの間には以下の関係
が成りたつ。
あるいは、
（Ｃｎ ） ＝ （ａ） （Ａｎ ）したが
って、求める放射能濃度は、
（Ａｎ ）＝ （ａ）（Ｃｎ ）
となる。ここで（丁）は（α）の逆行列。
ここでαは各仮想分割面からの測定点に対する幾何学的
効率を示す。言い換えれば、ある測定値ＣＩは６、各分
割面の真の放射能濃度に、それぞれの測定点に対する効
率を掛けたものの和で表わされる。そこで異なる測定点
を少なくとも仮想分割面以上選択することにより、行列
式を作成し、それを解くことにより、壁面での放射能分
布が求められる。なお、そのマトリクス（行列）の大き
さは、当然の事ながら仮想分割面の数に依存する。
また、効率ａは、検出器固有の計数効率と壁面の大きさ
や分割数とから幾何学的に求められる効率との積の形で
表わされる。
なお、上記放射線束の測定点は、壁面からの情報をより
多ぐ′含む位置であることが好ましく、建屋図面及び室
内の壁面構成から適宜選択しておく。
すなわち、この実施例の壁面放射能濃度測定方法では、
建屋壁面といった非常に大きな測定対象に対しての放射
能濃度分布を簡易かつ正確に得ることができ、従来では
なし得なかったマクロ評価が可能となる。
したがって、放射性物質取扱い施設の管理区域解除ある
いは改築といった比較的大規模な汚染評価が必要とされ
る場合に有用であるばかりでな（、汚染壁面を的確に示
すことにより、効率的除染を行う上で非常に有用である
。
［発明の効果］
以上述べたように、本発明の壁面放射能濃度測定方法に
よれば、従来に較べて簡易かつ正確に壁面放射能濃度分
布を求めることができ、測定に要する労力と時間の大幅
な削減および作業員の被曝低減を図ることができる。[Structure of the Invention] (Means for solving alil °) That is, the wall surface radioactivity concentration measuring method of the present invention measures radiation flux using a radiation detector at multiple points in a space corresponding to the wall surface to be measured, The radiation flux n1 to the wall surface
determining the radioactivity concentration distribution on the wall surface from a count determined as a product of a detection efficiency determined from a fixed position geometrical relationship and a counting efficiency specific to the radiation detector and a measurement result of the radiation flux; Features. (Function) In the wall surface radioactivity concentration measuring method of the present invention having the above-mentioned configuration, a radiation detector, etc., which is provided on a movable base having wheels or the like, and which is prevented from vertical movement by an elevating mechanism, etc. The radiation flux is measured at multiple points in the space corresponding to the wall surface to be measured. Then, the radioactivity concentration distribution on the wall surface is determined from the count obtained as the product of the detection efficiency obtained from the geometric relationship of the radiation flux measurement position with respect to the wall surface and the counting efficiency specific to the radiation detector, and the radiation flux measurement results. demand. Therefore, the wall surface radioactivity concentration distribution can be obtained more easily and accurately than in the past, and the labor and time required for measurement can be significantly reduced and the radiation exposure of workers can be reduced. (Example) Hereinafter, a method for measuring wall surface radioactivity concentration according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a wall surface radioactivity concentration measuring device for realizing a method according to an embodiment of the present invention, and in the figure, reference numeral 1 indicates a gamma ray detector. This γ-ray detector 1 is provided on a retractable pole 2, and can be fixed at a desired height by this pole 2. In addition, this pole 2 is fixed on a base 4 that has a plurality of wheels 3 and is configured to be movable on the floor, and by moving this base 4 and expanding and contracting the pole 2, gamma ray detection The device 1 is configured to be able to be set at a desired position within a building 5 and measure a three-dimensional radiation flux distribution. In this embodiment, using the wall surface radioactivity concentration measuring device having the above configuration, the wall surface radioactivity concentration is measured in the following manner. In other words, as shown in Figure 2, each wall surface of the building to be measured is virtually divided into multiple parts, and the necessary The radioactivity concentration for each virtual dividing surface of the wall is determined from the relationship with the three-dimensional efficiency from each virtual dividing surface of the wall to the specified position by sequentially repeating measurements at appropriate measurement positions. That is, in the example shown in Fig. 2, each wall surface is divided into four parts, and the radioactivity concentrations to be determined for these 24 divided faces are respectively At SA2 , ... AI ...
, A24, and the measured values as CI , C2,...C
t... Assuming C24, the following relationship holds between A and C. Alternatively, (Cn) = (a) (An) Therefore, the radioactivity concentration to be determined is (An) = (a) (Cn). Here, (Ding) is the inverse matrix of (α). Here, α represents the geometric efficiency for the measurement points from each virtual dividing plane. In other words, a certain measurement value CI is expressed as the sum of 6, the true radioactivity concentration of each split plane multiplied by the efficiency for each measurement point. Therefore, by selecting different measurement points at least on the virtual dividing plane, a determinant is created, and by solving it, the radioactivity distribution on the wall surface can be determined. Note that the size of the matrix naturally depends on the number of virtual dividing planes. Further, the efficiency a is expressed as the product of the counting efficiency specific to the detector and the efficiency geometrically determined from the size of the wall surface and the number of divisions. The measurement point of the radiation flux is preferably a position that includes more information from the wall surface, and is appropriately selected from the building drawing and the wall structure of the room. That is, in the wall surface radioactivity concentration measurement method of this example,
It is possible to easily and accurately obtain the radioactivity concentration distribution for a very large measurement target such as a building wall surface, making it possible to perform macroscopic evaluations that were not possible in the past. Therefore, it is not only useful when a relatively large-scale contamination assessment is required, such as deregulating or renovating the controlled area of a facility that handles radioactive materials. [Effects of the Invention] As described above, according to the wall surface radioactivity concentration measuring method of the present invention, the wall surface radioactivity concentration distribution can be determined more easily and accurately than before. , it is possible to significantly reduce the labor and time required for measurement and to reduce the radiation exposure of workers.
第１図は本発明の一実施例の壁面放射能濃度測定方法を
説明するための装置構成を示す図、第２図は建屋壁面の
仮想断面を示す図である。
１・・・・・・・・・・・・γ線検出器２・・・・・・
・・・・・・伸縮可能なボール３・・・・・・・・・・
・・車輪
４・・・・・・・・・・・・基台
５・・・・・・・・・・・・建屋
出願人 日本原子力事業株式会社代理人 弁
理士 須 山 佐 −
第１図
！FIG. 1 is a diagram showing the configuration of an apparatus for explaining a wall surface radioactivity concentration measuring method according to an embodiment of the present invention, and FIG. 2 is a diagram showing a virtual cross section of a building wall surface. 1...... Gamma ray detector 2...
・・・・・・Stretchable ball 3・・・・・・・・・・・・
...Wheel 4...Base 5...Building applicant Japan Atomic Energy Corporation Agent Patent attorney Sasu Suyama - Figure 1 !
Claims (1)
検出器により放射線束を測定し、前記壁面に対する前記
放射線束測定位置の幾何学的な関係から求められる検出
効率と前記放射線検出器固有の計数効率との積として求
められる計数と、前記放射線束の測定結果とから前記壁
面の放射能濃度分布を求めることを特徴とする壁面放射
能濃度測定方法。(1) Radiation flux is measured by a radiation detector at multiple points in the space corresponding to the wall surface to be measured, and the detection efficiency determined from the geometrical relationship of the radiation flux measurement position with respect to the wall surface and the characteristic of the radiation detector are determined. A method for measuring radioactivity concentration on a wall surface, characterized in that a radioactivity concentration distribution on the wall surface is determined from a count obtained as a product of a counting efficiency of the radiation flux and a measurement result of the radiation flux.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1072638A JPH02251784A (en) | 1989-03-25 | 1989-03-25 | Measuring method of radioactive concentration of wall surface |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1072638A JPH02251784A (en) | 1989-03-25 | 1989-03-25 | Measuring method of radioactive concentration of wall surface |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02251784A true JPH02251784A (en) | 1990-10-09 |
Family
ID=13495129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1072638A Pending JPH02251784A (en) | 1989-03-25 | 1989-03-25 | Measuring method of radioactive concentration of wall surface |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02251784A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005274367A (en) * | 2004-03-25 | 2005-10-06 | Atox Co Ltd | Apparatus for inspecting pollution of elevated large area |
| JP2007333463A (en) * | 2006-06-13 | 2007-12-27 | Mitsubishi Electric Corp | Radiation measuring apparatus |
-
1989
- 1989-03-25 JP JP1072638A patent/JPH02251784A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005274367A (en) * | 2004-03-25 | 2005-10-06 | Atox Co Ltd | Apparatus for inspecting pollution of elevated large area |
| JP2007333463A (en) * | 2006-06-13 | 2007-12-27 | Mitsubishi Electric Corp | Radiation measuring apparatus |
| JP4637794B2 (en) * | 2006-06-13 | 2011-02-23 | 三菱電機株式会社 | Radiation measurement equipment |
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