Abstract In order to reduce the time for core verification or visual inspection of BWR fuels, the underwater camera using a High- Definition camera has been developed. As a result of this development, the underwater camera has 2 lights and 370×400×328mm dimen sions and 20.5kg weight, Using the camera, 6 or so spent-fuel IDs are identified at lor 1.5m distance at a time, and 0.3mm $ pin-h ole is recognized at 1.5m distance and 20 times zoom-up. Noises caused by radiation less than 15Gy/h are not affected th...
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Development of underwater camera using High-Definition camea

This study proposes a novel nondestructive evaluation method of chill contents in gray cast irons by means of AC magnetization method. For the purpose, magnetic properties of cast irons w ith different chill contents were evaluated by B-H loop analyzer. Results were discussed in view of matrices and graphite, and it was found that some magnetic parameters, especially B-H l oop area, correlate well with ratio of cementite area to graphite one. Focusing on the fact, AC magnetic method was applied to evaluati...
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Evaluation of Chill Contents in Flaky Cast Irons Based on AC Magnetization Method

Inspection technique for complex surface profiles has been required in order to ensure the reliable operation and high operating rate of nuclear power plants, because many parts due to inspection have complex geometry. We have developed Pha sed Array (PA) ultrasonic testing with immersion technique which suitable to complex geometry. In this paper, we developed precise inspection technique for curvature surface profile such as a nozzle of pressure vessel. For curved surface pro file, Synthesis Aperture Foc...
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Development of Phased Array Inspection Technique for Nozzle Pipes with Curved Surface

Phased Array Ultrasonic Testing (PAUT) techniques for complex geometries are greatly progressing. We developed an immersion PAUT which is suitable for complex surface profiles such as nozzles and deformed welded areas. Furthermore, we have developed a shape adaptive beam steering technique for 3D complex surface structures with conventional array probe and flexible coupling gel which makes the immersion beam forming technique usable under dry conditions. This system consists of 3 steps. Step1 is surfac...
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Verification and Application of Beam Steering Phased Array UT Technique for Complex Structures

Laser peening is a surface enhancement process that introduces compressive residual stress on materials by irradiating laser pulses under aqueous environment. The process utilizes the impulsive effect of high-pressure plasma generated by ablative interaction of each laser pulse. It is very beneficial to shorten ou tage period if laser peening is available during refueling work. It is confirmed that laser peening can be available in the situation by experiment and analys is. This report describes detail of ...
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Study on availability of laser peening during refueling work- Preventive maintenance to shorten outage period

高温ガス炉は、基本構成要素である耐熱性の高いセラミックス製被覆燃料粒子や黒鉛減速材、不活性ヘリウム冷却材の特長を活用することで、高温熱を原子炉の外に取り出すことが可能である。図 1に高温ガス炉供給熱の温度範囲と熱利用が想定される産業プロセスの温度条件を示す。高温ガス炉供給熱の温度範囲は 100℃から 1000℃と幅広いため、発電のみならず種々の産業分野での熱利用が想定されている。例えば、エネルギー転換分野における原子力エネルギー利用の高効率化に資するヘリウム冷却材を用いたガスタービン発電、製鉄分野での還元剤・燃料や運輸分野における燃料電池自動車に供給する水素の熱化学水分解法やメタン水蒸気改質法による製造、炭酸ガス排出量の削減を目的としたスチレン等の化学製品製造やオイルシェール等の非在来型化石資源回収、石油精製プラントの熱源に用いる高温蒸気製造、発電システムでの排熱を利用した海水淡水化や地域暖房などでの多様な熱利用が期待される。 本稿では、高温ガス炉の熱利用技術として、発電熱電併給、再生可能エネルギーハイブリッドシステム及び熱化学法 ISプロセスの概要を述べる。...

In-Vessel Visual Inspection (IVVI) is usually conducted as indirect visual inspection with remote TV cameras. We often face the following issues in IVVI. When IVVI is conducted at narrow spa ce in the vessel, it is difficult for inspectors to set the cameras to the best position remotely and manually. When the cameras are quickly moved to reduce hours of IVVI, the visibility be comes poor because of motion blurs. For overcoming these problems, we focused on “Super Resolution (SR)” that is one of image proc...
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In-Vessel Visual Inspection System using Super Resolution Technique

A newly developed in-vessel visual inspection (IVVI) device designed to improve the quality of visual inspection in Boiling Water R eactors (BWRs) while providing significant critical path savings during refueling outages. And Super Resolution Visual Testing (VT) system enhances the inspection image resolution. The system assists the examiners under the condition of relatively faster scanning speed and longer work distance. The effectiveness of the time saving was qualified by the resolution testing with V...
英字タイトル:
Maintenance and Inspection Technologies for Shorter Outage

Mitsubishi Heavy Industries, LTD (MHI) developed accident tolerant in-containment hydrogen monitoring system that can operate under harsh environmental conditions during severe accident. The new hydrogen monitoring system consists of two types of detectors, which have different features and operating principles such as high sensitivity (for monitoring low hydrogen concentration) and wide range (for monitoring high hydrogen concentration of up to 20vol%), and hydrogen indication and transmitting module...
英字タイトル:
Development of In-containment Hydrogen Sensor System against Harsh Environment