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OTjapan Measures for Tsunami Striking Nuclear Power Station in Japan
Special Article: The Great Tohoku Earthquake (1)
OTjapan The Tragedy of “To Be” Principle in the Japanese Nuclear Industry
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ICMST-Kobe 2014
Nov 2(Sun) - 5(Wed), 2014
Kobe, Japan
Nuclear Regulation Authority Outline of the New Safety Standards for Light Water Reactors for Electric Power Generation
For Public Comment
Outline of New Safety Standard (Design Basis)
For Public Comment
New Safety Standards (SA) Outline (Draft)
For Public Comment
Outline of New Safety Standard(Earthquake and Tsunami)(DRAFT)
  Vol.5 No.4(Feb-25)
Vol.5 No.3(Nov-25)
Vol.5 No.2(Aug-26)
Vol.5 No.1(May-27)
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Featured Articles
EJAM5-3NT58 "Development of Future Prediction of Animation by coupling of Principle Component Analysis and Singular Spectrum Analysis"
EJAM5-3NT58 Validation of Multifrequency and Window-Multifrequency Techniques using Remote Field Eddy Currents for ISI of FBR Tubes
EJAM5-3NT59 Remote Controlled Robot with expandable features

(in English)

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Occasional Topics
OT8 (2010-1-28)
Hitachi Inspection Technology for Nuclear Power Plant
Masahiro Tooma*
Yoshiaki Nagashima*
Masahiro Koike**
Kojiro Kodaira**
*Hitachi, Ltd., Energy & Environmental Systems Laboratory
**Hitachi-GE nuclear energy, Ltd.
Eddy Current Testing, Ultrasonic Testing, Phased Array, Underwater Vehicle, Inspection Technology, Stress Corrosion Crack, Length Sizing, Depth Sizing, Core Internals, Nuclear Power Plant

Full Download( PDF)
 1. Hitachi Inspection Technology for Nuclear Power Plant
Masahiro Tooma
Yoshiaki Nagashima
Hitachi, Ltd., Energy & Environmental Systems Laboratory
Yutaka Kometani
Masayoshi Sonobe
Masahiro Koike
Kojiro Kodaira
Hitachi-GE nuclear energy, Ltd.
  2. Contents
  1. Introduction (Overview)
2. Eddy current testing (ECT)
3. Phased array UT
4. Underwater vehicle
5. Conclusion
  3. Overview of Hitachi Inspection Technology for NPP
  Inspection/Monitoring Technology
- Eddy Current Testing (ECT)
- Ultrasonic Testing (UT)
- Underwater Vehicle (ROV)
- Guided Wave Inspection
- Radiation Monitoring
  4. Objectives of Bottom Head Inspection
  Integrity Evaluation of Components at Bottom Head
- Welded to the Reactor Pressure Vessel (RPV)
- Nickel Alloy (SCC)
Nondestructive Testing (NDT)
- Detection of Stress Corrosion Crack (SCC)
- Length and Depth Sizing Measurement
  5. Contents
  1. Introduction (Overview)
2. Eddy current testing (ECT)
3. Phased array UT
4. Underwater vehicle
5. Conclusion
  6. Purpose of flexible Multi ECT Inspection
Conventional ECT
- Single ECT sensor : High sensitivity for SCC, but difficulty to apply to the complicated area
- Expanding inspection area to BHD
- Idea
    Rapid inspection: Multi coils
    Complicated area inspection: Flexible sensor
    Noise reduction: Phase mapping method
  7. Flexible Multi-coil ECT System
Eddy current sensor
ECT software display
  8. SCC Identification
Result of Identification
- We have developed an automatic crack signal identification system.
  9. Crack Length Sizing
  Crack length sizing method was authorized by JAPEIC.
10. Access tools
  6-axes robot arm
11. Contents
  1. Introduction (Overview)
2. Eddy current testing (ECT)
3. Phased array UT
4. Underwater vehicle
5. Conclusion
12. Array Sensors for OD Side of RPV
Optimization by UT Simulation
13. Equipment (2): Phased Array System
Electric Scanning of Ultrasonic Beam: Controlled by Phased Array System
14. Equipment (1): Automated Scanners
Array Sensor: Scanned on the OD Surface of RPV by Automated Scanner mounted on the Guide Rail
- H9 Shroud Support
- H11 Shroud Support
15. Results: H9(1) Horizontal Notch
Horizontal Notch
SN Ratio of Tip Echo: More than 6dB
16. Results of Depth Sizing (Notches)
Sizing accuracy for horizontal and vertical notches is less than 3mm (< ASME Code 0.125 inch)
17. Features of 3D Phased Array UT
18. Data Acquisitions for 3D Scans
Fast data acquisitions by 256 simultaneously active elements
19. Applications / FBHs in Metal Test Piece
- Metal Test Piece
- 3D Image of FBH
Scanned results can be evaluated at one time in a 3D view.
Echoes can be easily related to the reflection sources with the help of CAD data
20. Applications / Bolt Inspections
- Bolts (Φ24)
- 3D Image of Thread and Slit
Bolt inspections can be performed without any mechanical motions.
21. Contents
  1. Introduction (Overview)
2. Eddy current testing (ECT)
3. Phased array UT
4. Underwater vehicle
5. Conclusion
22. ROVs Lineup
23. C-type ROV
Detail of the C-type ROV
24. Inspection ROV : Specifications
25. The vector control using multiple thruster
Generate any motion by allocating thrust force to five thruster
26. The experimental result of the hovering control
Experimental setup
Appearance of the experiment
Experimental result
27. Conclusion
To carry out efficient inspection for core internal, shroud support and bottom mounted instrument of reactor pressure vessel, we have developed
the flexible multi-coil ECT system for novel identification and length sizing of surface breaking crack,
the phased array UT system for depth sizing of sub-surface breaking crack in thick-wall structure,
the remotely operated vehicles with these sensors.
EJAM OT8: "Hitachi Inspection Technology for Nuclear Power Plant" by Masahiro Tooma (Hitachi, Ltd), Yoshiaki Nagashima (Hitachi, Ltd), Masahiro Koike (Hitachi-GE nuclear energy, Ltd.) and Kojiro Kodaira(Hitachi-GE nuclear energy, Ltd.)