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Applied Laser Technology Institute
Japan Atomic Energy Agency
65-20 Kizaki Tsuruga-shi,Fukui-ken 914-8585,Japan P h o n e : +81-(0)770-21-5050 Facsimile: +81-(0)770-25-5782
Summary
Organization of Applied Laser Technology Institute
We are pursuing to develop useful laser based techniques in the field of nuclear engineering. At the same time we are also pursuing to develop the safe and robust techniques as advance industrial technology. We are happy to advertise our own efforts to the variety of industrial and academic societies all over the world to extend the applicability of laser and light technology originated from the nuclear applications. On the other hand, we are also very happy to make fruitful collaborations with people in Fukui prefecture such as Wakasa wan Energy Research Center, the University of Fukui and local industries.
H.Daido ,Director
Subjects of the Applied Laser Technology Institute
・Organization of symposiums, research meetings
○Various meetings of academic societies and so on
○Seminars
・Responding to business needs
○Implementation of laboratory tours from the industry
○Technology transfer to the industry
Laser Technology Promotion Office General Manager : Noboru Tsuchida
Applied Laser Technology Development Office General Manager : Toshiharu Muramatsu
Principal Researcher (Group Leader): Akihiko Nishimura
1 Summer intern ship Laboratory tours Result debrief session
Advertisement and consultation of development of laser technology for Industrial applications.
Research and development of laser techniques for nuclear engineering and nuclear facilities as well as industrial applications originated from nuclear engineering.
・The laser engineering for nuclear engineering and relevant techniques
・Outreach activities
○Summer Science Camp (for High school students)
○Organization of laboratory tours
○Summer internship ( for Graduate students and university students )
Applied Laser Technology Institute Director : Hiroyuki Daido
Noboru Tsuchida
Toshiharu Muramatsu Akihiko Nishimura
Hiroyuki Daido
Research content
・Development of fiber laser cutting and crushing techniques applied to removal of fuel debris for decommissioning of the Fukushima Daiichi NPPs.
・Monitoring techniques with laser and light technology for decommissioning of nuclear plants.
・Standardization of laser welding / cutting technologies supported by high quality experiments and computer science simulations.
・Maintenance and repair techniques of heat exchanger tubes in the nuclear facilities
・Medical applications of laser technology originated by nuclear engineering.
・Fundamental study on transparent sodium in the vacuum ultraviolet spectral range.
・Research on improving surface properties by laser irradiation
・Research and development of structural health monitoring with an optical fiber technique for a coolant pipeline of nuclear power plants
・Composition analysis for Laser Induced Breakdown Spectroscopy
Laser cutting experiment
2
Laser micromachining experiments
using a microscope objective
Laser irradiation experiments of
simulated blood vessel using a
composite optical fiber
Laser crushing experiment Laser cutting -crushing experiment
Heat exchanger tube repair experiment
Development of laser cutting and crushing control system and classification of irradiation conditions fit to an object . Experiments are being conducted by 6kW+4kW fiber lasers.
Reactor construction of nuclear power plant
Underwater laser cutting and crushing system
According to the decommissioning of the Three Mile Island Nuclear Power Station Unit 2, fuel debris were characterized by indefinite shapes, porous bodies, multi-compositions, higher-hardness.
Laser crushing by pulse irradiation
Laser cutting by a continuous irradiation
Development of fiber laser cutting and crushing techniques applied to removal of fuel debris for decommissioning of the Fukushima Daiichi NPPs.
Laser light
Laser light
20mm
10mm
Alumina pellet attachment
SUS304 austenitic stainless steel
1.A surface of a test piece is characterized as a complicated geometry.
2.An indefinite shape is measured by a 3D underwater laser scanner.
3.Form an optical path of a laser by an assist gas.
4. A continuous irradiation and pulsed irradiation makes it possible to cut the stainless steel and to crush the ceramic pellet underwater.
Shape scanning by 3D laser scanner
Laser power:6 kW
Pulse irradiation time:100 ms
Assist gas:compressed air
Assist gas flow rate:
350 ℓ/min.
Sweep velocity:30 mm/min.
Stand-off:5 mm
Water depth:130 mm
3
Laser Head
Assist gas Laser light
water
Indefinite shapes Higher hardness (Ceramics) Porous bodies (18±11%) Multi-compositions
Moving direction
Continuous wave irradiation
Pulsed irradiation
Continuous irradiation
water
Laser working head
Drag Lines
Dross
5mm
Inlet of coolant
Inlet of coolant
Upper grid damage
Solidifiedmaterial
Hole in the baffle plate
Ablated in-core instrument guide
Cavity
Core debris
Crust
Solidifiedmaterial
Lower plenum debris
Debris
12 m
Pore
Metallic ingots
Ceramic two-phase region (U, Zr)O2
200μm
Fuel debris microstructure
Laser cutting
The work is performed under the collaboration with the Wakasa Wan Energy Research Center, Fugen Decommissioning Research Center , etc. The objective of this collaboration is development of a nuclear reactor dismantling technique using a 6kW+4kW high-power fiber lasers.
Melting a target by laser irradiation.
Remove a molten metal by an assist gas.
Cutting
Mechanism of laser cutting
Underwater cutting example of stainless steel
Supplementary building for Reactor
Core of Reactor such as calandria tanks
Reactor building
Helium cleaning room, poison resolution room
Helium circulation system (3rd Floor)
Room for Cleaning heavy water
Kerf width : 1.5~2mm 1
0 c
m
15 cm
Laser illuminates from the audience.
Cross-section
5 c
m
Dross (Solidified molten metal)
Bird view of Transfer reactor “Fugen” under a decommissioning process.
Cutting direction
Laser light
Assist gas (compressed air)
Molten metal
Dragline
Nozzle
Test underwater laser of the cutting for decommissioning of a nuclear reactor.
4
Heat exchange pump for heavy water
Total Height:
66m
Monitoring techniques with laser and light technology for decommissioning of nuclear plants.
K
【Laser welding】 Toward the understanding of the welding phenomena and controlling the residual stresses, we have been developed a real-time X-ray imaging technique using an intense monochromatic X-ray beam and simulation code.
Standardization of laser welding / cutting technologies supported by high quality experiments and numerical simulation.
【Laser cutting】 Optimization of laser cutting conditions for decommissioning of aging nuclear power plants with help of the numerical simulation code.
【Multi-physics phenomena in a laser cutting process】
Real-time observation of interior of a molten pool during laser welding using an intense monochromatic X-ray beam at SPring-8.
The result of the SPLICE code which simulates interior of a molten pool during laser welding.
【Multi-physics phenomena in a laser welding process】
Real-time observation of laser cutting process using video camera The laser cutting simulation using SPLICE code
Laser working head
Steel plate
30 mm
Molten metal
Laser light
Tracer particle (Tantalum carbide)
Convection flow Solid phase
Molten pool Solid-liquid interface
1mm
Molten pool
Solid phase Solid-liquid interface
1mm
Steel plate
30 mm
Molten metal
Laser working head 1600
1400
1200
1000
800
600
400
200
0
Tem
pe
ratu
re [
oC
]
0
10
20
30
40
50
60
70
y [m
m]
0 10 20 30 40 50 60 x [mm]
25 m/s
Assist gas
5
Based on thermofluid dynamics Thermofluid dynamics, Fluid-solid interaction,
Surface transfer (gas-liquid-solid), Phase change
溶融金属対流領域
q..
き裂補修前処理部
半溶融帯q..
q..Heating Cooling
半溶融帯 半溶融帯凝固
熱伝導領域
レーザー光 レーザー光
加熱 冷却
溶融金属対流領域
q..
き裂補修前処理部
半溶融帯q..
q..Heating Cooling
半溶融帯 半溶融帯凝固
熱伝導領域
レーザー光 レーザー光
加熱 冷却
Laser cladding device to repair wall thinning in 1-inch tube
We have developed maintenance and repair techniques of heat exchanger tubes in nuclear facilities and industrial plants by composite-type optical fiberscope system. This was composed of a central fiber for beam delivery surrounded by fibers for visible image delivery including illumination.
We could irradiate the work with the best accuracy of laser beam and with a filler wire in laser cladding. This device was designed to work in a 1-inch tube.
Demonstration of laser cladding by a welding expert
Example of a clad on a flat plate.
A welding expert successfully made a line clad on a flat plate by manual handling of a laser torch and a wire.
Simulated thinning
SS400 test piece
The guide tube
Welding wire
Laser light
Molten droplet
X-ray shadowgraph of a laser cladding process
A molten droplet of a wire tip was formed and grew up. It is important that the wire is contact with a base metal to make a clad.
6
Laser light
Wire
Laser spot
1 mm
Heat exchange tube
Adjust the position of the wire and laser heats guides by an observation image
Wall thinning of petrochemical plant
23 mm
Thinning point (A shadowed area)
10 mm
900 mm
150 mm
Cross section
Maintenance and repair techniques of heat exchanger tubes in the nuclear facilities
Heat exchanger tube
Laser torch
Visible and near-infrared heat-resistant mirror
Condenser lens
Argon gas Wire feeder
Circumferential position adjustment
Z-axis position adjustment
Composite-type optical fiber
Coupling device
Heat source (QCW fiber laser)
Laser spot
We should pay careful attention to the strength degradation at every aging welded joints when massive earthquakes may attack nuclear power plants. Advanced monitoring system is now getting more important against coming catastrophic earthquakes along the Nankai Trough.
Heat resistant strain sensor fabricated by ultra-short laser processing
We are now fabricating heat resistant strain sensors using an ultra-short pulsed laser in our laboratory. The installation of the stain sensors on the sodium coolant pipeline of Fast Breeder Reactor is under development.
Core
Grating structure in a fiber core
Reflection of the grating structure shows peak shift due to strain and heat.
Ultra-short laser pulses can generate a grating structure along a fiber core (Fiber Bragg Grating :FBG). The FBG can hold the designed reflection peak even over 600 ℃. Such a superior heat resistance can make it possible that laser cladding strongly embedded it on a SUS plate.
Weld bead sealing a FBG sensor in a SUS plate
Heating laser pulses
Seismic-vibration-strain measurement under laser heating by heat resistant FBG sensor
7
1545 1550 1555 1560
Wavelength (nm)
1545 1550 1555 1560
Processing stage and microscope Ultra-short pulse laser system
Femtosecond laser pulse
Oscillator Pulse stretcher
Regenerative amplifier
Multi-pass amplifier
Pulse compressor
Objective lens
1m 100mm stage
1mm
10mm
50μm
Irradiating a laser at equal intervals
Research and development of structural health monitoring with an optical fiber technique for a coolant pipeline of nuclear power plants
Detection light
Minimally invasive laser treatment device
We have developed a laser treatment system that keeps minimum damage to patients and treat precisely by irradiating a laser while watching the affected part. Started to commercialize at OK Fiber Technology Co., Ltd. that is the venture company certified by JAEA.
Optical fibers for image transmission (~f4 mm ,~10,000 pixels)
A fiber for laser irradiation (f100~200μm, 1 unit)
f1~2mm
Optical fibers for illumination
Applications of Minimally invasive laser treatment device
Laser source
CCD camera
Dichroic mirror Coupling device
Source for illumination
Monitor
Illumination light Laser
Image
Composite-type optical fiber scope
Composite-type optical fiber Constitution of device
Laser hyperthermia for cancer of the uterine body
Photodynamic therapy (PDT) for peripheral lung cancer
Non‐occlusive bypass surgery
Hemostasis of bloody issue Diagnostic equipment
for Bile duct and Pancreatic duct Small-bowel endoscope
for the ileus patient
Development of laser treatment system for early cancer of the uterine body that can be uterus-sparing.
Peripheral lung cancer
(The onset in the peripheral part)
Endoscope
Development of laser treatment system for peripheral lung cancer that can observe and treat.
Building a tool that allows to bypass surgery without cutting off the blood flow.
Development of non-contact hemostatic tool using a laser.
Aneurysm
Recipient vessel
Donor vessel
Incision and suturing of the vessel wall
Endoscope
cerebral hemorrhage
Development of diagnostic equipment without having to incise the duodenum papilla.
Gallbladder
Liver
Bile duct
Pancreas
Duodenum papilla
Endoscope
Pancreatic duct Small bowel disease
Development of a new small bowel endoscope that combines optical fiber scope and ileus tube.
8
Medical applications of laser technology originated by nuclear engineering.
Uterine cancer (The onset in the uterine body)
Layout drawing of sodium transparent
Optical property of alkali metals including sodium was intensively investigated in the 20th century. Wood and Sutherland et al. Obtained the plasma wavelength of 218 nm. In the wavelength range of 218 nm, the sodium can be partially transparent down to the threshold of the core electron excitation wavelength of 40.5 nm. On the basis of the previous works, we should extend the characterization into much thicker sodium region to clarify the value of the coefficient. We have made the direct measurement of actual transmittance of a sodium samples in a spectral range longer than 115 nm, resulting in several tens of % transmittance of a 3 mm-thick solid sodium sample including windows at the wavelength of ~120 nm
Experimental setup of an imaging experiment
Image of the metal mesh. A blackened area corresponds to that covered with a pyrex glass plate which is opaque in the vacuum ultraviolet spectral range.
The extinction coefficient ~5 orders of magnitude lower than the previous result. We also find very weak temperature dependency of the transmittance up to 150 degrees centigrade where the solid sample is melted at 97 degrees. In order to confirm measured transmittance, we also make a simple imaging experiment with a 8-mm-thick sodium sample. The photo of the sample and the mesh with the optical system is shown. We successfully obtain a clear image The result opens a way to construct an optical imaging device for objects inside or through a solid or a liquid sodium medium. The result also encourages us to find out the physical origin of the high transparency.
9
10 mm
Heater
Sodium sample (Thickness=8mm) Phosphor
+ CCD
MgF2 Lens
MgF2 Lens VUV light
Deuterium lamp
MgF2 Windows
Mesh
Pyrex glass
Fundamental study on transparent sodium in the vacuum ultraviolet spectral range.
Sodium dedicated glove box
Material irradiation technique by laser pulses
We are trying to improve surface properties of materials by laser irradiation. Nanosecond or femtosecond laser pulses are available for industrial demands. A compact vacuum chamber, X-Y linear translation stage, focusing optics are prepared. Highly trained technical staff will support you to proceed your study. Surface modification for advanced materials is under development by laser irradiation.
Example was continuously irradiated over a wide range of materials
A sample was held on a material position control stage in an irradiation chamber. Laser light timing is controlled by a mechanical shutter. It is possible to perform the sample in various irradiation environments such as an inert gas atmosphere or under reduced pressure depending on the characteristics of the material.
10
Laser irradiation range
Irradiation target sample range
About 1.1cm
Irradiation interval =150μm
Users can try surface modifications for a test sample with femtosecond laser pulses.
Examples of materials irradiation test environment
State of the material irradiation test
Laser light
Material position control stage
Irradiation chamber
100mm
Test system
Control system
Monitoring system
1mm
Research on improving surface properties by laser irradiation.
When laser pulses are focused on a target, one can see a tiny flash by laser induced plasma on the target. This can be used for a real time composition analysis of the target material. A nanosecond laser pulse can generate plasma effectively. By combining a laser system, a multichannel spectrometer and fiber optics, you can get the information of breakdown plasma emission spectra.
11
Spectral comparison of the welded parts and piping material by LIBS
This technique is named laser-induced breakdown spectroscopy.(”Laser-Induced Breakdown Spectroscopy”=LIBS). The following is an example to apply LIBS to the mold made by laser cladding. It can also be applied to verify the distribution of specific elements on the sample. You can see that the chromium containment is higher at the cladding mold (yellow) than that of piping material (red).
300 400 500 600 700 800 900 1000
配管材料
溶接部分
鉄
クロム
Stre
ngt
h[a
.u.]
Wavelength[nm]
Peak of chromium-specific
Coupling device
CCD camera
Spectroscope
Plasma emission on the sample surface
Video observation monitor
Acquisition of spectrum
Composite-type optical fiber
Laser Pulse
Laser pulse Visible Image
10mm 100mm
0.8mm
0.2mm
Example of the combination of the monitoring system and laser equipment
Piping material
Cladding mold
Iron
Chromium
Composition analysis for Laser Induced Breakdown Spectroscopy.
12
6kW+4kW Fiber laser:
Laboratory equipment
Chiller
Laser oscillator
4kW
6kW
Water depth 3m
≪ Applications ≫ Development of laser processing technology aimed at using in general industrial facilities and nuclear facilities. ≪ Specifications ≫ ・4kW Fiber Laser,Chiller Emission Wavelength:1070 ~1080nm Nominal Output Power:4 kW ・6kW Fiber Laser,Chiller Emission Wavelength:1070 ~1080nm Nominal Output Power:6 kW
Particle Image Velocimetry (PIV) system
≪ Applications ≫ Development on the quantitative evaluation method of an assist gas flow related to laser cutting. ≪ Specifications ≫ ・ Double-pulsed Nd: YAG laser Wavelength :532nm, Power :50mJ/pulse, Repetition rate :20Hz Pulse width:6~8ns ・High-speed camera
Test flow channel
Nozzle
High-speed camera
Laser sheet
Equipment for High-Power Laser Welding
Equipment for High-Power Laser Cutting in Air / Under Water
≪ Applications ≫ Development of technology for laser welding of same kind or different kinds of materials intended for thick plates. ≪ Specifications ≫ ・x-y-z Stage,Welding jig
≪ Applications ≫ Development of laser cutting in air / under water. ≪ Specifications ≫ ・X-Y-Z Triaxial Robot System Speed Range : 5 mm/min~5000 mm/min ・Laser Scanner Wavelength :520 nm, Power :30 mW, Waterproof Performance : Maximum Water Depth 100 m ・ Water Tank Maximum Water Depth:3 m
Laser Welding head
Welding jig
x-y-z Stage
Laser scanner head
Test pieces
X-Y-Z Triaxial
450mm
Laser Cutting Head
Robotic arm
Joint research with The Wakasa Wan Energy Research Center, Fugen, Lasax.
Inner wall laser welding repair device for a heat exchanger tube
Femtosecond laser system
≪ Applications ≫ Fiber Bragg Grating(FBG) processing into the optical fiber. Development of ultra-short pulsed laser processing. ≪ Specifications ≫ ・Laser unit Center wavelength :790nm Pulse width :~150fs Pulse energy:~10mJ Repetition rate :~1kHz ・ Processing stage and microscope
≪ Applications ≫ Technical development of weld repair of metal piping and other. ≪ Specifications ≫ ・Fiber laser 1)YLR-300-AC:Wavelength:1,070nm,CW,Power:300W 2)YLR-150/1500/QCW:Wavelength:1,070nm,Pulse/CW, Pulse width:0.2-50ms,Power:150W/250W(CW) ・ Coupling device : Light guide up to 1kW , The observation by the CCD camera ・Composite optical fiber:(Core fiber)Φ0.2mm (Image transmission fiber)About 20,000 ・ Laser torch :Φ15mm,Length:120mm, Jet of gas can be ・ Wire feeder :Φ0.4mm use wire,Feed rate:0.5-20mm/s
13
Q-switched Nd:YAG laser
≪ Applications ≫ Development of pulsed laser processing. ≪ Specifications ≫ ・ Laser unit Wavelength:1064nm or 532nm(SHG) Pulse width :5-7ns Pulse energy : ~ 270mJ@1,064nm,
~130mJ@532nm Repetition rate :10Hz ・ Processing stage
150cm
77cm
Soft X-ray and ultraviolet spectroscopy, microscopy test equipment
14
≪ Applications ≫ Fundamental and applied studies on ultraviolet light and soft x-ray such as measurement of sodium transmission , microscopy , and surface cleaning. ≪ Specifications ≫ ・Soft X-ray microscope Wavelength:20nm,4nm Optics:Schwarzschild Resolution in the XY direction :100nm Observed area :1mm×1mm Resolution in the Z direction :30nm Imaging range :40×40μm~200×200μm ・ Soft X-ray, ultraviolet spectrometer Main vacuum vessel : Inner diameter 560mm Vacuum ultraviolet spectrometer : Wavelength 100nm~300nm Soft X-ray spectrometer : Wavelength 0.5nm~5nm,5nm~30nm
Minimally invasive laser treatment equipment 1
≪ Applications ≫ Development of techniques of irradiating a laser to the affected area while watching an image using the composite optical fiber. ≪ Specifications ≫ ・Fiber laser YLR-50-SMLP:Wavelength 1,070nm,CW,Power 50W ・Blood flow meter ・Coupling device ・Control of certain irradiation output ・Monitor ・Composite optical fiber
Minimally invasive laser treatment equipment 2
≪ Applications ≫ Development of techniques to observe the affected area by placing minimally invasively optical fiber inside pancreas. ≪ Specifications ≫ ・Uninterruptible power system ・Image observation device ・Monitor ・Optical fiber:outer diameter 0.8mm
45cm
Applied Laser Technology Institute at Quantum Beam Science Center, Sector of Nuclear Science Research Japan Atomic Energy Agency (JAEA)
and at Tsuruga Head Office
65-20 Kizaki Tsuruga-shi,Fukui-ken 914-8585 Japan Phone☎:+81-(0)770-21-5050 Facsimile:+81-(0)770-25-5782
Home page:http://www.jaea.go.jp/04/turuga/laser/index.html
Revised:July 7th 2014
Tsuruga Head Office/ Applied Laser technology Institute
Fugen Decommissioning Engineering Center
Fast Breeder Reactor Research and Development
Center
FBR Safety Technology Center/ International Nuclear Information
and Training Center
【Photo】 The Tsuruga Peninsula from a airplane on the Japan sea.
Tsuruga Station
The Wakasa Wan Energy Research Center