JPS62257078A - Distribution type radiation measuring system - Google Patents
Distribution type radiation measuring systemInfo
- Publication number
- JPS62257078A JPS62257078A JP10181286A JP10181286A JPS62257078A JP S62257078 A JPS62257078 A JP S62257078A JP 10181286 A JP10181286 A JP 10181286A JP 10181286 A JP10181286 A JP 10181286A JP S62257078 A JPS62257078 A JP S62257078A
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- radiation
- loss
- atmosphere
- reflected light
- 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
- 230000005855 radiation Effects 0.000 title claims abstract description 63
- 239000013307 optical fiber Substances 0.000 claims abstract description 81
- 238000010438 heat treatment Methods 0.000 claims abstract description 30
- 238000005259 measurement Methods 0.000 claims description 18
- 230000005540 biological transmission Effects 0.000 claims description 17
- 239000002184 metal Substances 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 7
- 230000005611 electricity Effects 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 abstract description 21
- 239000010949 copper Substances 0.000 abstract description 21
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 abstract description 20
- 238000001514 detection method Methods 0.000 abstract description 5
- 239000000835 fiber Substances 0.000 description 12
- 239000011247 coating layer Substances 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 5
- 229920006231 aramid fiber Polymers 0.000 description 4
- 206010073306 Exposure to radiation Diseases 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 150000001879 copper Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000012857 radioactive material Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 231100000987 absorbed dose Toxicity 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 239000008280 blood Substances 0.000 description 1
- 210000004369 blood Anatomy 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 238000000253 optical time-domain reflectometry Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
Landscapes
- Measurement Of Radiation (AREA)
Abstract
Description
【発明の詳細な説明】
「産業上の利用分野」
この発明は、短時間でかつ区域外において遠方から放射
線雰囲気を測定することができろとともに、被曝した先
ファイバを容易に再使用できる経「従来技術とその問題
点Ｊ
原子力発電所や原子力関連の研究施設などにおいて、こ
れら施設内外の作業区域内では、従来より例えばガイガ
ーカウンタなどの放射線計測器を用いて作業区域を全域
に亙ってくまなく放射線強度を測定することによって放
射線管理が行なわれている。Detailed Description of the Invention "Industrial Field of Application" The present invention is a method for measuring a radiation atmosphere from a distance outside an area in a short time, as well as for easily reusing a fiber that has been exposed to radiation. Conventional technology and its problems J At nuclear power plants and nuclear-related research facilities, radiation measuring instruments such as Geiger counters have traditionally been used to monitor the entire working area inside and outside of these facilities. Radiation control is carried out by measuring radiation intensity.
ところが、このような方法による放射線管理に ゛あっ
ては、放射線の測定に時間がかかるとともにその測定中
に測定音が放射線雰囲気内に立ち入った際に被曝する危
険があるなどの問題があった。However, radiation control using this method has problems such as the time it takes to measure radiation and the risk of exposure to radiation if the measurement sound enters the radiation atmosphere during the measurement.
「問題点を解決するための手段」
そこで、この発明の分布型放射線測定システムは、その
構成を光ファイバと、この光ファイバ上に設けられた金
属発熱体と、上記光ファイバの一端部に接続されかつ上
記光ファイバ内に先パルスを入射しその反射光を受光し
てＯＴＤＲ法により放射線による光ファイバの部分的な
伝送損失増加を倹Ｍ＋−４−る測定装置と、上記金属発
熱体に通電し送損失を回復させる加熱装置とからなる乙
のとしたことにより、上記の問題点を解消するようにし
た。"Means for Solving the Problems" Therefore, the distributed radiation measurement system of the present invention has an optical fiber, a metal heating element provided on the optical fiber, and a metal heating element connected to one end of the optical fiber. and a measuring device that injects a first pulse into the optical fiber and receives the reflected light to reduce the partial increase in transmission loss of the optical fiber due to radiation using the OTDR method, and energizes the metal heating element. The above-mentioned problem has been solved by providing a heating device that recovers the transmission loss.
「作用 Ｊ
このような構成からなる分布型放射線測定システムにあ
っては、先ファイバの周囲が放射線雰囲気とｔろと、光
ファイバか被曝し、この被曝部分の光ファイバが劣化し
、光ファイバの伝送損失が部分的に増加する。このとき
、上記の光ファイバの一端部から光パルスを入射すると
、光ファイバの損失増加位置で反射した反射光パルスの
時間的な遅れを検出して光ファイバの入力端からの被曝
位置を測定することができ、また反射光パルスの変化か
ら損失増加量を知ることかできる。よって、上記の光フ
ァイバの損失位置と損失増加量とにより放射線雰囲気の
位置と放射線強度とを知ることができる。``Effect J'' In a distributed radiation measurement system with such a configuration, when the surroundings of the tip fiber enter a radiation atmosphere, the optical fiber is exposed to radiation, and the optical fiber in this exposed portion deteriorates, causing damage to the optical fiber. Transmission loss partially increases.At this time, when an optical pulse is input from one end of the optical fiber, the time delay of the reflected optical pulse reflected at the position of increased loss of the optical fiber is detected and the optical fiber is The exposure position from the input end can be measured, and the amount of loss increase can be determined from changes in the reflected light pulse.Therefore, the position of the radiation atmosphere and the radiation You can know the strength.
また、このシステムにあっては、加熱装置により金属発
熱体に通電してこれを加熱することによって光ファイバ
の伝送損失を回復させることができるので、光ファイバ
を取り替えることなく、放射線センサとして光ファイバ
を放射線測定に繰り返し使１ｔｌてきる。In addition, in this system, the transmission loss of the optical fiber can be recovered by applying electricity to the metal heating element and heating it using the heating device, so the optical fiber can be used as a radiation sensor without replacing the optical fiber. 1 tl can be used repeatedly for radiation measurements.
「実１血例」 以−ト、図面を参照してこの発明の詳細な説明する。"One actual blood case" The present invention will now be described in detail with reference to the drawings.
第１図は、この発明の分布型放射線測定７ステムの一例
を示す乙のであって、図中符号ｌは光ファイバ障害点検
出器（以下、検出器と略称する。）である。FIG. 1 shows an example of the seven distributed radiation measurement systems of the present invention, and reference numeral l in the figure represents an optical fiber failure point detector (hereinafter abbreviated as detector).
検出器ｌは、後述の光ファイバの入力端から光パルスを
入射し反射光パルスの時間的な遅れを検出ずろＯＴ Ｄ
ｎ （Ｏｐｔｉｃａｌ Ｔ ｉｍｅ Ｄ ｏｍａ
ｉｎＥｌ ｅｒｒｅｃｔｒｏｍｅＬｅｒ）法を利用し１
ニ乙のであって、このらのは光ファイバの入力端から光
パルスを入射するパルス発生器と発光ダイオードとから
なる発光部と、光ファイバからフレネル反射光や後方散
乱光などの反射光パルスを受光する光検出部と、この光
検出部で受光されｆ二叉射光パルスの時間的な遅れを演
算処理する演算部と、この処理結果を表示する表示部と
からなるものである。そして、この検出器ｌの検出感度
は、放射線雰囲気下で劣化した光ファイバの損失増加量
が０．５ｄＢ／Ｎ程度以下である場合、この損失増加を
十分に検出できろ程度であることが望ましい。この検出
器ｌには、先ファイバ２の一端部が接続されている。The detector l receives a light pulse from the input end of an optical fiber, which will be described later, and detects the time delay of the reflected light pulse.
n (Optical Time Doma
1 using the inEl errectromeLer) method.
These two components include a light emitting unit consisting of a pulse generator and a light emitting diode that input optical pulses from the input end of the optical fiber, and a light emitting unit that receives reflected light pulses such as Fresnel reflected light and backscattered light from the optical fiber. It consists of a photodetection section that receives light, a calculation section that processes the time delay of the f-bifurcated light pulse received by the photodetection section, and a display section that displays the processing results. The detection sensitivity of this detector l is preferably such that it can sufficiently detect the increase in loss of an optical fiber degraded in a radiation atmosphere when the increase in loss is about 0.5 dB/N or less. . One end of the tip fiber 2 is connected to this detector l.
この光ファイバ２は、その周囲が放射線雰囲気となった
際に部分的に伝送損失が増加する放射線センサであって
、この乙のは、第２図に示すように光ファイバ裸ｔｉＡ
３と、−次被覆層４と、二次被覆層５と、銅−組（金属
発熱体）６と、アラミツド繊維層７と、ジャケット８と
からなるものである。This optical fiber 2 is a radiation sensor whose transmission loss partially increases when the surrounding area becomes a radiation atmosphere, and as shown in FIG.
3, a secondary coating layer 4, a secondary coating layer 5, a copper set (metal heating element) 6, an aramid fiber layer 7, and a jacket 8.
光ファイバ裸線３は、僅かな量の放射線によって伝送損
失が大きく増加する（放射線感度が高い）放射線センサ
であって、このものの放射線感度（損失増加量）は、通
常の計画被曝量３０ＲＲ７日程度以下の放射線環境下に
おいて上記の検出器１の検出感度に匹敵する程度である
ことが望ましい。そして、この光ファイバ裸線３として
は、放射線によ１ 少Ｉし λＩＡ−”ｃ／ に
ＩＡ ＋１圧 ツ、半 七 ■＼ ダ に廿ムーイ
ニ フコアファイバなどが好適に用いられ、その外径は
通常１００〜１５０μ次程度の範囲とされる。この先フ
ァイバ裸線３の外周面一にには、この光ファイバ裸線３
を外力から保護する変性ノリコーン樹脂やノリコーン樹
脂などからなる一次披ｒｒ１層４が形成され、その膜厚
は通常１００〜１５０μａ程度の範囲とされる。The bare optical fiber 3 is a radiation sensor whose transmission loss greatly increases (high radiation sensitivity) due to a small amount of radiation, and its radiation sensitivity (loss increase) is about 30RR7 days, which is the normal planned exposure dose. It is desirable that the detection sensitivity be comparable to the detection sensitivity of the detector 1 described above under the following radiation environment. Then, as for this optical fiber bare wire 3, 1 little I λIA−”c/ to IA +1 pressure tsu, half 7 ■＼ da to 廿mui due to radiation
A nifcore fiber or the like is preferably used, and its outer diameter is usually in the range of about 100 to 150 μm. From now on, on the outer peripheral surface of the bare fiber wire 3, this bare optical fiber wire 3 is
A primary layer 4 made of modified oricone resin or the like that protects the substrate from external forces is formed, and its thickness is usually in the range of about 100 to 150 μa.
この−次彼蕩層、１上には、さらに光ファイバ２の取扱
性を容易にして作業性を向上さけろためのナイロンなと
からなる二次被覆層５が形成され、モの膜厚は通常１０
０〜２５０μｍ程度の範囲とされるつさらによｆコ、二
次被覆層５上には、後述の加熱装置に連結して加熱装置
の加熱により光ファイバ裸線３の１云送損失を回復させ
る長尺の銅編組６が被覆ごれている。この銅編組６は、
外径０．１ｆｆｉａ程度の銅線か編まれてなる乙のであ
って、その波頂［１７はＪｉ！ｉ富’ １５０〜２５０
μｄ程度５）範囲とされろ。さらに、この銅編組６」二
には、先ファイバ２に機ｔａ的強度を付５ ’：ｉるア
ラミツトａ百ｒ層７が４００〜５００μに程度のＰ７５
て設；すらイｔでいる。このアラミツド繊維層７は、１
ｕ敗の長尺あるいは短尺のアラミツド繊椎を光ファイバ
２の長手方向に沿って配設されてなるものである。そし
て、このアラミツド繊維層７上には、銅編組６の熱を光
ファイバ２内に保持することにより光ファイバ裸線３の
伝送損失を効率良く回復さ仕るｎめのジャケント８がＰ
Ｉｉ覆されている。このジャケット８を形成する（オ料
としては、耐熟性を有する塩化ビニル樹脂などの合成樹
脂が好適に用いられ、ジャケット８の膜厚は、通常４５
０〜５５０μ屑程度の範囲とされろ。A secondary coating layer 5 made of nylon is further formed on this secondary coating layer 1 to facilitate handling of the optical fiber 2 and improve workability. Usually 10
Further, the secondary coating layer 5 has a thickness in the range of about 0 to 250 μm, and is connected to a heating device, which will be described later, to recover the transmission loss of the bare optical fiber 3 by heating the heating device. The long copper braid 6 is covered with dirt. This copper braid 6 is
It is made of woven copper wire with an outer diameter of about 0.1 ffia, and its wave crest [17 is Ji! i wealth' 150~250
5) Let the range be about μd. Furthermore, this copper braid 6'' has a P75 layer 7 of about 400 to 500μ, which adds mechanical strength to the end fiber 2.
It's easy to set up. This aramid fiber layer 7 has 1
The optical fiber 2 is made up of long or short aramid fibers arranged along the longitudinal direction of the optical fiber 2. Then, on this aramid fiber layer 7, there is an n-th jacket 8 that efficiently recovers the transmission loss of the bare optical fiber 3 by retaining the heat of the copper braid 6 within the optical fiber 2.
Ii has been overturned. This jacket 8 is formed (as the material, a synthetic resin such as vinyl chloride resin having aging resistance is preferably used, and the film thickness of the jacket 8 is usually 45 mm.
It should be in the range of 0 to 550 micron particles.
このような光ファイバ２は、例えば第１図に示すように
原子力発電所等の作業区域９の全域にくまなく配設され
ている。For example, as shown in FIG. 1, such optical fibers 2 are disposed throughout a working area 9 of a nuclear power plant or the like.
そして、このように構成された光フフイバ２の銅編組６
の両端部間には、加熱装；ξｌＯか配設されている。こ
の加熱装置ｌＯは、上記銅編組６の両端部間に通電して
光ファイバ裸線３を加熱し、この銅編組６の発熱により
光ファイバ裸線３の放射線被曝による伝送損失を回復さ
せるもので、光ファイバ２の長さにより必要な電流を供
給できろ可変電圧の電源である。Then, the copper braid 6 of the optical fiber 2 configured in this way
A heating device; ξlO is disposed between both ends of the . This heating device IO heats the bare optical fiber 3 by passing current between both ends of the copper braid 6, and uses the heat generated by the copper braid 6 to recover the transmission loss of the bare optical fiber 3 due to radiation exposure. It is a variable voltage power supply that can supply the necessary current depending on the length of the optical fiber 2.
次に、ここ０よ−：ｒ ｆ； ４１“り成からなる分布
型放射線測定システムを用い几放射線の測定方法の一例
を説明する。まず、作業区域９内の全域にくまなく配設
されｆコ光ファイバ２の一端部を検出器１に接続する。Next, an example of a method for measuring radiation using a distributed radiation measurement system consisting of 41" components will be explained. One end of the optical fiber 2 is connected to the detector 1.
次に、光ファイバ２の銅編組６の両端部間に」二足の可
変電圧の電源を接続してシステムが完成する。Next, two variable voltage power supplies are connected between both ends of the copper braid 6 of the optical fiber 2 to complete the system.
しし、作業区域９内のへ区画が放射線雰囲気とな−た場
ｈ、その、へ区画内の光ファイバ２が彼曝し検知＋＋Ｊ
能となる。そして、例えば作業開始前に検出器ｌにより
先ファイバ２の損失増加を検知する。オなわち、先ファ
イバ２の入力端から光ファイバ２内に発光部より光パル
スを入射し、この光パルスのフレネル反射光や後方散乱
光などの反射光パルスを光検出部で受光し、反射光パル
スの時間的な遅れを演Ｊγ部で演算処理する。この反射
光パルス５つ時間的な遅れにより光ファイバ２の入力端
からの損失位置を測定するとともに、反射光パルスの変
化から損失増ｌＩＪ量を検出する。そして、この光ファ
イバ２の損失位置と損失増加量とにより放射線雰囲気の
位置（被曝位置）と放射線強度とを知ることができる。However, if the compartment in the working area 9 is in a radiation atmosphere, the optical fiber 2 in the compartment will be exposed to radiation.
Becomes Noh. Then, for example, before starting the work, an increase in loss in the tip fiber 2 is detected by the detector 1. In other words, a light pulse is input from the light emitting part into the optical fiber 2 from the input end of the tip fiber 2, and reflected light pulses such as Fresnel reflected light and backscattered light of this light pulse are received by the light detection part and reflected. The time delay of the optical pulse is processed by the calculation unit Jγ. The loss position from the input end of the optical fiber 2 is measured by the time delay of these five reflected light pulses, and the amount of loss increase lIJ is detected from the change in the reflected light pulses. The position of the radiation atmosphere (exposed position) and the radiation intensity can be determined from the loss position and the amount of loss increase in the optical fiber 2.
次いで、この測定データから検出器ｌの位置で作業区域
９のＡ区画の放射線雰囲気を検知してへ区画内への立ち
入りを制限あるいは禁止するなどの対応措置をとる。Next, based on this measurement data, the radiation atmosphere in section A of the working area 9 is detected at the position of the detector 1, and countermeasures are taken, such as restricting or prohibiting entry into the section.
次に、光ファイバ２の銅編組６の両端部間に加熱装置Ｉ
Ｏにより所定の電圧を所定時間印加して銅編組６を加熱
する。この銅編組６の発熱により光ファイバ裸線３の部
分的な劣化を解消ずろ。このときの銅編組６に対する加
熱温度は、光ファイバ裸線３の劣化の度合などに応じて
決められるが、通常６０〜１２０°Ｃ程度の範囲とされ
る。６０℃未満では、光ファイバ裸線３の劣化を回復さ
せるのに時間かかかり過ぎるなどの不都合が生じ、また
１２０℃を越える場合では、得られる効果が頭打ちとな
り、不経済となる。Next, a heating device I is placed between both ends of the copper braid 6 of the optical fiber 2.
The copper braid 6 is heated by applying a predetermined voltage with O for a predetermined time. Partial deterioration of the bare optical fiber 3 due to the heat generated by the copper braid 6 can be eliminated. The heating temperature for the copper braid 6 at this time is determined depending on the degree of deterioration of the bare optical fiber 3, but is usually in the range of about 60 to 120°C. If the temperature is less than 60°C, there will be problems such as it takes too much time to recover from the deterioration of the bare optical fiber 3, and if the temperature exceeds 120°C, the effect obtained will reach a ceiling and become uneconomical.
この分布型放射線測定システムにあっては、作業区域９
内に光ファイバ２を配設し、この先ファのて、作業区域
９内が放射線雰囲気となる事態となってしその事態を検
出器１の近傍において迅速に検知セろととらに、その放
射線雰囲気の状態（放射線強度）を、１１１定すること
が可能である。また、この分４１型枚射線測定ンステム
にあっては、光ファイバ２内に加熱装置ＩＯに連結士ろ
銅編組６を設けた乙のであるので、加熱装置１０により
銅編組６を加熱−４−ろことにより放射線被曝による光
ファイバ裸線３の伝送損失を迅速かつ確実に回復さ仕る
ことかてきろ。In this distributed radiation measurement system, the work area 9
If an optical fiber 2 is disposed inside the working area 9 and a radiation atmosphere develops in the working area 9, the radiation atmosphere can be quickly detected near the detector 1. It is possible to determine the state (radiation intensity) of 111 times. In addition, in this type 41 sheet ray measurement system, since the coupling copper braid 6 is provided in the heating device IO within the optical fiber 2, the copper braid 6 is heated by the heating device 10. By doing so, the transmission loss of the bare optical fiber 3 due to radiation exposure can be quickly and reliably recovered.
上記の実施例て：よ、広範な作業区域を測定対象とした
か、例えばその制定対象を放射性物質格納容器とし、こ
の容器の外壁面全面に検出器に接続され几光−７アイバ
を張り巡らした構成であってもよい。この場合、容器の
破損なとによる容器内の放射性物質の漏出事故等を迅速
に検知することが可能でとうる。In the above example, a wide range of work areas was the object of measurement, for example, the object was a radioactive material storage container, and the outer wall of this container was connected to a detector and lined with phosphor-7 fibers. It may also have a different configuration. In this case, it may be possible to quickly detect leakage of radioactive materials within the container due to damage to the container.
以下、実験例を示す。Experimental examples are shown below.
（実験例１ ）
？ＴｒｌｆＪｌ＋−］＝−−１−ト−二、ｒ、Ｑｋ＃１
％１１．）＊７１ｅ：、−ｙ２Ｊ、を全長１００Ｒの多
成分ガラスコアファイバを用いて作製した。この先ファ
イバを放射線雰囲気（放射線吸収線量１０Ｒａｄｓ）下
に置き、放射線による光ファイバの損失増加量を測定し
たところ、その放射線雰囲気を０．５ｄＢ／７＋の光フ
ァイバの伝送損失として測定することかでさた。また、
放射線雰囲気の位置確認を行な〜たところ、光ファイバ
の長手方向に沿って＝Ｉｘの誤差範囲で放射線雰囲気の
場所を確認することができた。(Experiment example 1)? TrlfJl+-]=--1-T-2, r, Qk#1
%11. )*71e:, -y2J, was produced using a multi-component glass core fiber with a total length of 100R. After placing the fiber in a radiation atmosphere (radiation absorbed dose: 10 Rads) and measuring the amount of loss increase in the optical fiber due to radiation, it was found that the radiation atmosphere was measured as the transmission loss of the optical fiber of 0.5 dB/7+. Ta. Also,
When the location of the radiation atmosphere was confirmed, it was possible to confirm the location of the radiation atmosphere along the longitudinal direction of the optical fiber within an error range of =Ix.
（実験例２ ）
多成分ガラスコア光ファイバ１００１を６０分、１ｏＲ
ａｄｓ照射したのち、銅編組を加熱装置により下記の条
件で約１０（１°Ｃとなるまで加熱した。すなわち、銅
編組の両端部間に印加した電圧を約５０Ｖとし、電流を
約１５Ａとし、その出力を約８００Ｗとした。(Experiment Example 2) Multi-component glass core optical fiber 1001 was heated at 1oR for 60 minutes.
After the ADs irradiation, the copper braid was heated to about 10°C (1°C) using a heating device under the following conditions. That is, the voltage applied between both ends of the copper braid was about 50V, the current was about 15A, The output was approximately 800W.
銅編組全体の温度の安定を考慮して約１２０分間、銅編
組を加熱し続けた。そして、上記の光ファイバの伝送損
失を加熱処理前から経時的に測定したところ、第３図の
グラフに示すような結果を得た。The copper braid was continued to be heated for about 120 minutes in consideration of stabilizing the temperature of the entire copper braid. When the transmission loss of the above optical fiber was measured over time before the heat treatment, results as shown in the graph of FIG. 3 were obtained.
第３図から明らかなように、光ファイバは照射中損失増
加が大きいが、照射を中止して加熱を開始すると急激に
その損失が低下することがわかる。As is clear from FIG. 3, the optical fiber has a large loss increase during irradiation, but when the irradiation is stopped and heating is started, the loss decreases rapidly.
そして、全部で１２０分間の加熱処理を施すことにより
光ファイバの伝送損失が零に近い水錦まで収束すること
がわかる。したがって、この分布型放射線測定ンステム
においては、放射線により光ファイバの損失が増加して
も光ファイバの再生が可能であるので、光ファイバの取
り替えを行なう必要がなく、同じ光ファイバを再生して
繰り返し使用することができるとともに、長期間使用す
ることかできるので経済的である。It can be seen that by performing the heat treatment for a total of 120 minutes, the transmission loss of the optical fiber converges to near zero. Therefore, in this distributed radiation measurement system, even if the loss of the optical fiber increases due to radiation, it is possible to regenerate the optical fiber, so there is no need to replace the optical fiber, and the same optical fiber can be regenerated repeatedly. It is economical because it can be used for a long period of time.
「発明の効果ｆ
以上説明したように、この発明の分布型放射線測定ソス
テムは、光ファイバの周囲が放射線雰囲気となると光フ
ァイバの伝送損失か部分的に増加し、この損失増加を測
定装置により測定することが可能であるので、光ファイ
バの損失増加位置から放射線雰囲気の位置を短時間に検
知し、かつ光ファイバの損失増加量から放射線強度を正
確に測定す之ことが可能であるとともに、光ファイバに
対して加熱処理を施すことが可能であるので、光ファイ
バの伝送損失を低減させて光ファイバを被＠館の状態に
まで回復させろことが可能である。"Effects of the Invention f As explained above, in the distributed radiation measurement system of the present invention, when a radiation atmosphere exists around an optical fiber, the transmission loss of the optical fiber partially increases, and this loss increase is measured by a measuring device. Therefore, it is possible to detect the position of the radiation atmosphere from the position of increased loss in the optical fiber in a short time, and to accurately measure the radiation intensity from the increased amount of loss in the optical fiber. Since it is possible to perform heat treatment on the fiber, it is possible to reduce the transmission loss of the optical fiber and restore the optical fiber to a damaged state.
また、この分布型放射線測定システムによれば、放射線
雰囲気を例えば作業開始前に知ることができるので、作
業者等を誤って被曝させることなく作業者等の安全を確
保することができろ。Further, according to this distributed radiation measurement system, the radiation atmosphere can be known, for example, before the start of work, so that the safety of the workers can be ensured without accidentally exposing them to radiation.
第１図はこの発明の分布型放射線測定システムの一例を
示す概略構成図、第２図はこの発明の分布型放射線測定
システムの光ファイバの一１３’ｌｉを示す概略斜視図
、第３図はこの発明の分布型放射線測定ンステムの光フ
ァイバのｊｎ失回復例を示すグラフである。
ｌ・・・光ファイバ障害点検出器（測定装置）、２・・
・光ファイバ、６ 銅−組（金属発熱体）、ｌＯ・・加
熱装置。FIG. 1 is a schematic configuration diagram showing an example of the distributed radiation measurement system of the present invention, FIG. 2 is a schematic perspective view showing one optical fiber 13'li of the distributed radiation measurement system of the invention, and FIG. It is a graph showing an example of jn loss recovery of the optical fiber of the distributed radiation measurement system of the present invention. l...Optical fiber failure point detector (measuring device), 2...
- Optical fiber, 6 copper sets (metal heating element), lO... heating device.
Claims (1)
体と、上記光ファイバの一端部に接続されかつ上記光フ
ァイバ内に光パルスを入射しその反射光を受光してＯＴ
ＤＲ法により放射線による光ファイバの部分的な伝送損
失増加を検知する測定装置と、上記金属発熱体に通電し
これを加熱することによって上記光ファイバの伝送損失
を回復させる加熱装置とからなる分布型放射線測定シス
テム。An optical fiber, a metal heating element provided on the optical fiber, and a metal heating element connected to one end of the optical fiber, which injects a light pulse into the optical fiber and receives the reflected light.
A distributed type consisting of a measuring device that detects a partial increase in transmission loss of an optical fiber due to radiation using the DR method, and a heating device that restores the transmission loss of the optical fiber by applying electricity to the metal heating element and heating it. Radiation measurement system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10181286A JPS62257078A (en) | 1986-05-01 | 1986-05-01 | Distribution type radiation measuring system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10181286A JPS62257078A (en) | 1986-05-01 | 1986-05-01 | Distribution type radiation measuring system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS62257078A true JPS62257078A (en) | 1987-11-09 |
Family
ID=14310540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10181286A Pending JPS62257078A (en) | 1986-05-01 | 1986-05-01 | Distribution type radiation measuring system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62257078A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL2025411B1 (en) * | 2020-04-23 | 2021-11-01 | Optical Fibre Dosimetry B V | Radiation monitoring device and inspection system. |
-
1986
- 1986-05-01 JP JP10181286A patent/JPS62257078A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL2025411B1 (en) * | 2020-04-23 | 2021-11-01 | Optical Fibre Dosimetry B V | Radiation monitoring device and inspection system. |
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