EP0507641B1 - Verfahren und Einrichtung zum Arbeiten mit Laser in einer kontaminierten Zone einer Nuklearanlage - Google Patents

Verfahren und Einrichtung zum Arbeiten mit Laser in einer kontaminierten Zone einer Nuklearanlage Download PDF

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Publication number
EP0507641B1
EP0507641B1 EP92400622A EP92400622A EP0507641B1 EP 0507641 B1 EP0507641 B1 EP 0507641B1 EP 92400622 A EP92400622 A EP 92400622A EP 92400622 A EP92400622 A EP 92400622A EP 0507641 B1 EP0507641 B1 EP 0507641B1
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EP
European Patent Office
Prior art keywords
amplifier
laser
laser beam
amplified
electrode
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
Application number
EP92400622A
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English (en)
French (fr)
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EP0507641A1 (de
Inventor
Jean-Pierre Cartry
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.)
Areva NP SAS
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Framatome SA
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Publication date
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B7/00—Cleaning by methods not provided for in a single other subclass or a single group in this subclass
    • B08B7/0035—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by radiant energy, e.g. UV, laser, light beam or the like
    • B08B7/0042—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by radiant energy, e.g. UV, laser, light beam or the like by laser
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
    • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
    • G21F9/28—Treating solids
    • G21F9/30—Processing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/002—Component parts or details of steam boilers specially adapted for nuclear steam generators, e.g. maintenance, repairing or inspecting equipment not otherwise provided for
    • F22B37/003—Maintenance, repairing or inspecting equipment positioned in or via the headers
    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
    • G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
    • G21F9/001—Decontamination of contaminated objects, apparatus, clothes, food; Preventing contamination thereof
    • G21F9/005—Decontamination of the surface of objects by ablation

Definitions

  • the present invention relates to a method and an installation for laser work on a surface contained in a contaminated area of a nuclear installation.
  • the invention applies in particular to the decontamination by laser beam, in aqueous or gaseous medium, of surfaces which have received a deposit of radioactive materials such as activated metal oxides, in order to reduce the level of radiation and thus allow the access or approach of response personnel.
  • the primary circuit of pressurized water nuclear power plants is concerned with this invention and more particularly the water box of the steam generators and the primary pipes.
  • Decontamination may be necessary during a check or repair to be carried out in the contaminated part of the plant, when replacing equipment such as a steam generator, and also when dismantling this plant.
  • the object of the invention is to make it possible to work efficiently by means of a laser in a contaminated area.
  • a pulsed laser beam is emitted outside the contaminated area, this beam is transported by means of an optical fiber to a location close to said surface, and, at this location, the beam is amplified and the amplified beam is sent onto said surface, possibly by means of a deflection mirror, the laser beam, after amplification, having pulses having an energy of 0 , 3 to 5 joules, or more, a duration of 10 to 30 ns, and an energy density of 1 to 15 J / cm2.
  • FIG. 1 there is shown in Figure 1, in axial section, one 1 of the two compartments of the water box 2 of a steam generator of a pressurized water nuclear reactor.
  • This compartment 1 is delimited upwards by the tubular plate 3, on one side by the middle vertical partition 4 of the water box, and on the other side and downwards by the hemispherical bottom 5 of the water box , which is crossed by a manhole 6.
  • a equipment 7 adapted to allow the decontamination by laser beam of the surfaces which delimit compartment 1.
  • This equipment comprises an external apparatus 8 arranged outside the water box, in an appropriate room protected from radiation, and an internal apparatus 9 arranged inside compartment 1 and which can be introduced therein through the manhole.
  • the apparatus 8 comprises a control console 10, a generator of electrical energy and fluids 11, a pulsed laser beam generator 12, constituted by an oscillator possibly followed by a preamplifier, and a suction pump 13 at the inlet which is provided with a filter 14.
  • the apparatus 9 comprises a laser beam amplifier 15 and a confinement enclosure 16 carried by a support 17.
  • the input of the amplifier 15 is connected to the output of the generator 12 by an optical fiber 18 of multimode type having a length at least about 15 m.
  • the enclosure 16 is connected on the one hand, via a line 19, to a source of protective (neutral or reducing) or active gas contained in the generator 11, and on the other hand, via a line 20, to the filter 14 and at the pump 13.
  • the support 17 constitutes the end of an articulated robot, shown diagrammatically at 21, remotely controlled from the console 10 and making it possible to arrange the apparatus 9 facing any region of the surfaces 3, 4, 5 to decontaminate and in the vicinity thereof.
  • the apparatus 9 is shown in more detail in Figure 2.
  • the amplifier 15 is housed in a housing 22 fixed to the support 17 and provided with supply lines 23 and power supply 24 and 25 for cooling water discharge. Lines 23 to 25 are connected via a line 26 ( Figure 1) to the generator 11.
  • An inlet face of the housing 22 is pierced with an orifice in which the distal end of the optical fiber 18 is fixed, and an inlet optic 27 makes it possible to introduce at the input of the amplifier 15 a parallel beam of diameter equal to that of the bar of the amplifier.
  • This amplified spring beam at the other end of the amplifier 15, and its diameter is reduced by an exit optic 28, then leaves the housing 22 in the form of a parallel pulsed beam through an exit orifice 29.
  • the support 17 carries a frame 30 in which several columns 31 parallel to the axis X-X of the amplifier 15, biased by springs 32 in the opposite direction to this amplifier, are slidably mounted.
  • the enclosure 16, which has a cup shape, has a bottom 33 perpendicular to the axis XX which is fixed to the distal end of the balusters 31, and a side wall 34 whose free edge is provided with rollers 35.
  • the bottom 33 has an orifice 36 of axis XX whose diameter is slightly greater than that of the amplified beam 37.
  • the laser generator 12 is of a type allowing the transport of the beam by optical fiber. It can in particular be of the Nd-YAG type (wavelength 1.06 ⁇ m), of the sapphire type (wavelength centered on 0.78 ⁇ m) or of the excimer type (wavelength 0.3 ⁇ m) . It emits pulses with a duration of 10 to 30 ns.
  • This generator 12 and the amplifier 15 are adjusted to provide an amplified beam 37 whose pulses have an energy of 0.3 to 5 joules or more and an energy density (or fluence) of 1 to 15 J / cm2.
  • rollers 35 are applied, with a force determined by the springs 32, to the surface to be decontaminated, which is the partition 4 in the example shown.
  • a protective or active gas scans the enclosure 16, and the pulsed beam emitted by the generator 12, transported by the optical fiber 18 and amplified at 15, is sent directly, in the form of the parallel beam 37, to the surface to be treated, perpendicular to it. All the surfaces to be decontaminated are scanned in this way by moving the support 17 by means of the robot 21.
  • the above-mentioned energy density is chosen so as to allow thermal penetration corresponding to the thickness, or part of the thickness, of the layer of radioactive oxide to be eliminated, each pulse creating a shock wave on this layer.
  • the use of a neutral or sweeping gas reduces the oxidation of the etched surface, while the use of an active gas, in particular oxygen, makes it possible to increase the thickness of the oxide layer. interested in laser pulses.
  • the choice of sweep gas will therefore be established according to the specific conditions of each application.
  • the use of a multimode optical fiber for the transport of the unamplified laser beam provides a considerable advantage linked to the energy distribution in the beam leaving said fiber, and therefore at the level of the beam impact spot. on the wall. Indeed, in this case, the energy distribution is substantially constant over the entire surface of the spot; it is in the form of a slot instead of having a distribution comprising a central peak as is the case with transmission of the beam by air.
  • the fiber must be long enough for the energy homogenization to be correct, for example at least 15 m. With a shorter optical fiber, it would be appropriate in certain cases to use in the generator 12 a so-called "Gaussian" mirror, known per se, providing a homogeneous, niche distribution of energy.
  • the apparatus 9A shown in Figure 3 differs from that of Figure 2 in that the support 17 is arranged so that the axis X-X of the amplifier 15 is parallel to the surface to be treated.
  • the posts 31 are perpendicular to this axis X-X, and a deflection mirror 38 inclined at 45 ° is fixed opposite the orifice 36 of the enclosure 16.
  • This variant is particularly applicable to laser work in reduced spaces, for example to decontaminate the wall of primary pipes.
  • the variant of Figure 3 can be modified as follows: the 16-column 31-mirror enclosure assembly 38 is connected to the support 17 by means of another support mounted mobile on the latter, in translation and / or in rotation about the axis of the amplifier 15. It is thus possible, for each position of the amplifier , effectively sweep a relatively large region to be treated, regardless of the shape of this region.
  • Figure 4 illustrates means other than suction means for capturing the oxide particles detached from the surface by the impact of the laser beam. It is in this case an electrode 39 held parallel to the surface to be treated by spacers not shown and pierced with an orifice 40 allowing the passage of the laser beam 37. This electrode is carried, thanks to a power supply 41 , at a high potential with respect to the treated surface, so that the detached oxide particles, ionized by the laser beam, are attracted to the electrode 39.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Optics & Photonics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Food Science & Technology (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Laser Beam Processing (AREA)
  • Lasers (AREA)
  • Cleaning In General (AREA)

Claims (8)

  1. Verfahren zur Dekontaminierung einer Fläche (3, 4, 5) innerhalb einer kontaminierten Zone einer Nuklearanlage mittels eines impulsförmigen Laserstrahls (12), der außerhalb der kontaminierten Zone abgegeben wird, dadurch gekennzeichnet, daß dieser Strahl mittels einer Lichtleitfaser (18) bis zu einer Stelle transportiert wird, die nahe bei der genannten, in der kontaminierten Zone befindlichen Fläche liegt, und daß an dieser Stelle der Strahl verstärkt wird (15) und der verstärkte Strahl (37), eventuell über einen Umlenkspiegel (38), auf die genannte Fläche gesandt wird, wobei der Laserstrahl nach der Verstärkung Impulse mit einer Energie von 0,3 bis 5 Joules oder mehr, einer Dauer von 10 bis 30 ns und einer Energiedichte von 1 bis 15 J/cm² hat.
  2. Verfahren nach Anspruch 1,
    dadurch gekennzeichnet, daß während der Arbeit mit dem Laser ein Schutzgas oder aktives Gas in den Arbeitsbereich geleitet wird.
  3. Verfahren nach Anspruch 1 oder 2,
    dadurch gekennzeichnet, daß der Arbeitsbereich eingeschlossen ist und daß während der Arbeit mit dem Laser das in dem eingeschlossenen Bereich enthaltene Gas abgesaugt wird.
  4. Verfahren nach einem der Ansprüche 1 bis 3,
    dadurch gekennzeichnet, daß der verstärkte Strahl (37) durch eine Öffnung (40) einer Elektrode (39) geleitet wird, die parallel zu der genannten Fläche ist, und daß während der Arbeit mit dem Laser ein elektrisches Feld zwischen dieser Elektrode und der genannten Fläche erzeugt wird.
  5. Einrichtung zur Dekontaminierung einer Fläche (3, 4, 5) innerhalb einer kontaminierten Zone (2) einer Nuklearanlage mittels Laser zur Durchführung eines Verfahrens nach einem der Ansprüche 1 bis 4,
    dadurch gekennzeichnet, daß sie umfaßt:
    - einen Erzeuger von impulsförmigen Laserstrahlen (12) des Typs Nd-YAG, Saphir oder Exzimer, der eventuell mit einem Gaußschen Umlenkspiegel ausgestattet ist, der außerhalb der kontaminierten Zone (2) angeordnet ist,
    - einen Laserstrahlen-Verstärker (15),
    - eine Lichtleitfaser (18) zum Transport des impulsförmigen Laserstrahls bis zum Eingang dieses Verstärkers, wobei diese Lichtleitfaser (18) eine Länge von mindestens ca. 15 m hat, und
    - Mittel (21) zum Verschieben des Verstärkers (15) gegenüber der genannten Fläche und in deren Nähe.
  6. Einrichtung nach Anspruch 5,
    dadurch gekennzeichnet, daß sie einen Umlenkspiegel (38) aufweist, der am Ausgang des Verstärkers (15) und eventuell beweglich gegenüber diesem angebracht ist.
  7. Einrichtung nach Anspruch 5 oder 6,
    dadurch gekennzeichnet, daß sie einen Einschlußbehälter (16) aufweist, der zusammen mit dem Verstärker (15) oder mit dem Spiegel (38) verschiebbar ist und mit Absaugmitteln (13, 14, 20) und ggf. mit Mitteln (19) zum Einführen eines Schutzgases oder aktiven Gases versehen ist.
  8. Einrichtung nach einem der Ansprüche 5 bis 7
    dadurch gekennzeichnet, daß sie eine Elektrode (39), die parallel zu der genannten Fläche liegt, mit einer durchgehenden Öffnung (40) für den Durchlaß des verstärkten Laserstrahls versehen ist und zusammen mit dem Verstärker (15) verschiebbar ist, sowie Mittel (41) zur Erzeugung eines elektrischen Feldes zwischen dieser Elektrode und der genannten Fläche aufweist.
EP92400622A 1991-04-05 1992-03-10 Verfahren und Einrichtung zum Arbeiten mit Laser in einer kontaminierten Zone einer Nuklearanlage Expired - Lifetime EP0507641B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR919104189A FR2674983B1 (fr) 1991-04-05 1991-04-05 Procede et equipement de travail au laser dans une zone contaminee d'une installation nucleaire.
FR9104189 1991-04-05

Publications (2)

Publication Number Publication Date
EP0507641A1 EP0507641A1 (de) 1992-10-07
EP0507641B1 true EP0507641B1 (de) 1995-09-20

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ID=9411538

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Application Number Title Priority Date Filing Date
EP92400622A Expired - Lifetime EP0507641B1 (de) 1991-04-05 1992-03-10 Verfahren und Einrichtung zum Arbeiten mit Laser in einer kontaminierten Zone einer Nuklearanlage

Country Status (9)

Country Link
EP (1) EP0507641B1 (de)
KR (1) KR920020528A (de)
CA (1) CA2062623A1 (de)
DE (1) DE69204879T2 (de)
ES (1) ES2078681T3 (de)
FR (1) FR2674983B1 (de)
RU (1) RU2084978C1 (de)
TW (1) TW201356B (de)
ZA (1) ZA922453B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3100002A1 (fr) 2019-08-21 2021-02-26 Onet Technologies Cn Procédé pour décontaminer par laser pulsé une pièce métallique comprenant à sa surface une couche d’oxydes de métaux

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2168413C (en) * 1995-01-31 2000-04-18 Kouki Okazaki Underwater laser processing method and apparatus
RU2199162C1 (ru) * 2001-10-08 2003-02-20 Максимов Лев Николаевич Способ переработки отработавшего ядерного топлива (оят) и устройство для его осуществления
GB2391691B (en) * 2002-08-07 2006-02-08 Remote Marine Systems Ltd Method and apparatus for removing material from a target object
FR2879101B1 (fr) * 2004-12-14 2007-03-02 Cogema Decontamination laser de la surface d'une piece profilee.
FR2894711B1 (fr) 2005-12-09 2009-04-10 Cogema Dispositif et procede de decontamination automatisee d'un crayon de combustible nucleaire
RU2468457C1 (ru) * 2011-08-03 2012-11-27 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Санкт-Петербургский национальный исследовательский университет информационных технологий, механики и оптики" Способ удаления радиоактивной пленки с поверхности объекта
CN104438227B (zh) * 2013-09-16 2018-12-18 上海海固电器设备有限公司 一种飞机蒙漆激光清洗设备
CN104438230A (zh) * 2014-11-17 2015-03-25 成都莱普科技有限公司 工业制品激光清洗系统及其控制方法
CN112605068A (zh) * 2020-12-15 2021-04-06 湖南大学 一种耐辐照可变焦激光清洗装置及使用方法
CN113198802B (zh) * 2021-05-17 2022-07-12 圣同激光设备(上海)有限公司 一种大幅面激光清洗机

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LU71852A1 (de) * 1975-02-14 1977-01-05
DE3310117A1 (de) * 1982-04-05 1983-10-06 Maxwell Lab Verfahren zur photochemischen entseuchung
CA1198482A (en) * 1982-04-14 1985-12-24 Thaddeus A. Wojcik Laser decontamination method
JPS61242273A (ja) * 1985-04-18 1986-10-28 株式会社フジタ 鉄筋コンクリ−ト構造物の切断工法及びその装置
JPS63241399A (ja) * 1987-03-30 1988-10-06 株式会社東芝 レ−ザ除染装置

Non-Patent Citations (1)

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Title
WORLD PATENTS INDEX LATEST, Derwent Publications Ltd, London, GB, AN AN-88-327038 & JP-A-63 241 399 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3100002A1 (fr) 2019-08-21 2021-02-26 Onet Technologies Cn Procédé pour décontaminer par laser pulsé une pièce métallique comprenant à sa surface une couche d’oxydes de métaux

Also Published As

Publication number Publication date
ES2078681T3 (es) 1995-12-16
DE69204879D1 (de) 1995-10-26
TW201356B (de) 1993-03-01
ZA922453B (en) 1993-10-04
EP0507641A1 (de) 1992-10-07
FR2674983A1 (fr) 1992-10-09
DE69204879T2 (de) 1996-04-04
KR920020528A (ko) 1992-11-21
FR2674983B1 (fr) 1994-08-05
RU2084978C1 (ru) 1997-07-20
CA2062623A1 (fr) 1992-10-06

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