第13回
Experimental investigation on jet breakup behavior in the lower plenum of a boiling water reactor under isothermal conditions
著者:
Hongyang WEI,Nejdet ERKAN,Koji OKAMOTO
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In a hypothetical severe accident, the fuel assemblies and structure in the core region could melt. The corium from the core region may fall into the reactor lower plenum. Jet breakup phenomenon would happen while corium falling into water pool in the lower plenum. In a boiling water reactor lower plenum, the control rod guide tubes (CRGTs) will create flow channels for the falling jet. Therefore corium jet breakup behavior could be affected by these CRGTs. Thus, it is important to investigate CRGTs effe...
英字タイトル:
Experimental investigation on jet breakup behavior in the lower plenum of a boiling water reactor under isothermal conditions
第13回
Simultaneous Velocity and Temperature Measurements inside Suspended Droplet in Hot Air Flow using TSPs & PIV
著者:
周 騫,Qian ZHOU,Nejdet ERKAN,岡本 孝司,Koji OKAMOTO
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Containment spray cooling is a part of nuclear reactor safety system, which can condense the steam into liquid within the containment structure to realize depressurization and temperature decrease during a reactor accident. In order to investigate the space spray mechanism, which is the heat and mass transfer between falling droplets and surrounding gas, 2-D temperature distribution and velocity field inside a suspended water droplet in upward hot air stream was measured using combined temperature-sens...
英字タイトル:
Simultaneous Velocity and Temperature Measurements inside Suspended Droplet in Hot Air Flow using TSPs & PIV
論文
THALES-2 によるフィルターベントシステムの有効性評価
著者:
近藤 雅裕,Masahiro KONDO,吉本 達哉,Tatsuya YOSHIMOTO,石川 淳,Jun ISHIKAWA,岡本 孝司,Koji OKAMOTO
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Filter vent model for THALES-2 code was developed and the effect of the filter vent system was evaluated with the code. In Japan, the installation of filter venting system to the BWRs was considered after the accident of Fukushima-daiichi, where the total blackout caused by tsunami resulted in the large amount of fission product (FP) release to the environment. In this study, the effect of filter vent system in such a total blackout sequence was evaluated. The amount of fission product release was sma...
英字タイトル:
Effectiveness Evaluation of Filtered Containment Venting System using THALES-2
第14回
ジオポリマーを活用した燃料デブリ取り出し工法の提案
著者:
鈴木 俊一,Shunichi SUZUKI,岡本 孝司,Koji OKAMOTO
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1.緒言 福島第一原子力発電所廃炉の課題を克服するためには、数多くの視点から課題を捉える必要がある [1]。前報告では俯瞰的視点で捉えた、燃料デブリ取り出し、廃棄物管理、及び遠隔技術の3分野の要求機能について概念を示した[2]。本報告ではこのうち燃料デブリ取り出しに絞って、どのような工法が有効であるか議論を行う。なお、工法アイデアを創出するためのブレーンストーミングは、原子力技術専門家の他、化学プラント、再処理技術、土木・建築技術、粉塵技術などに関する学内外の専門家の意見を反映して実施した。 2.燃料デブ......
英字タイトル:
A new method of fuel debris retrieval with geopolymer for Fukushima Dai-ichi NPP
第13回
下部プレナム制御棒支持管のジェットブレークアップ挙動への影響解析
著者:
結城 喬,Takashi YUKI,近藤 雅裕,Masahiro KONDO,岡本 孝司,Koji OKAMOTO,韋 宏洋,Hongyang WEI
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Abstract In 2011 at Fukushima Daiichi Nuclear Power Plant, which was a boiling water reactor (BWR), core meltdown occurred. There are control rod guide tubes (CRGTs) in lower plenum of pressure vessel of BWR and it is considered that CRGTs influence behavior of jet breakup of corium. In this research, the experiment about difference of behavior of jet breakup with and without pillar, which simulate CRGTs, and mechanism of difference of behavior of jet breakup in [5] was simulated and analyzed by parti...
英字タイトル:
Influence of Control Rod Guide Tubes in Lower Plenum for Behavior of Jet Breakup
第13回
俯瞰的アプローチによる福島第一廃止措置の新たな工法検討
著者:
鈴木 俊一,Shunichi SUZUKI,田村 雄介,Yusuke TAMURA,岡本 孝司,Koji OKAMOTO
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The mission of decommissioning of Fukushima Dai-ichi NPP is the long-term, complicated and difficult task. In this paper, technical strategies and expected technical challenges will be discussed for its accomplishment. ...
英字タイトル:
Systems thinking for Fukushima Dai-ichi Decommissioning
第5回
原子力発電所の機器等の地震安全に関する技術課題の抽出と研究・開発ロードマップの提案
著者:
岡本 孝司,Koji OKAMOTO,高木 敏行,Toshiyuki TAKAGI
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This paper describes technical issues for the seismic safety of nuclear power plant components and also shows preliminary roadmaps for the solution of the issues. After the Chuetsu-oki earthquake of July 2007, research committees were established in JSME and AESJ for the disc ussion of the effect of the earthquake on NPP components. Ten technical issues due to the earthquake are pointed out and the discussion co ncerning the roadmaps has started to solve each issue. The goal of the activity is for the adva...
英字タイトル:
Proposal of R&D Roadmaps for Technical Issues of the Seismic Safety of Nuclear Power Plant Components
第14回
国際標準プロアクティブエキスパート育成
著者:
菅野 眞紀,Masanori KANNO,関村 直人,Naoto SEKIMURA,岡本 孝司,Koji OKAMOTO,糸井 達哉,Tatsuya ITOI,エルカン ネジェット,Nejdet ERKAN,蛇川 季嗣,Suetsugu JAGAWA
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After Fukushima Daiich Accident, some international organizations have been discussed on importance of defense in depth (DiD), total comprehensive evaluation contained 14 Safety Factors in PSR (IAEA SSG-25) and HOF (Human and Organization Factors). The NRA allowed review by the IAEA Integrated Regulatory Review Service (IRRS) mission team, over the twice of 2008 and 2016. As a few recommendation examples on above these points to NRA, acquisition of human resources as able talented person and personnel...
英字タイトル:
Human resource Development Activities lesson learned International standard after Fukushima Daiichi Accident towards a Proactive Nuclear Regulatory
第7回
基調講演: 運転中保全-リスクと保全
著者:
岡本 孝司,Koji OKAMOTO
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Abstract Online maintenance is a option of advanced maintenance system started on 2009. With the risk for hardware and software, the online maintenance for important system will be considered to be better than that of offline maintenance. The key issue is the improve ment of software system including the human factor and organizing systems on maintenance....
英字タイトル:
Online Maintenance
第13回
断層変位に対する工学的なリスク評価 (1)事故シナリオと工学的対策
著者:
奈良林 直,Tadashi NARABAYASHI,岡本 孝司,Koji OKAMOTO,亀田 弘行,Hiroyuki KAMEDA,蛯沢 勝三,Katsumi EBISAWA,山崎 晴雄,Haruo YAMAZAKI,神谷 昌伸,Masanobu KAMIYA,小長井 一男,Kazuo KONAGAI,長澤 和幸,Kazuyuki NAGASAWA,千葉 豪,Go CHIBA
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Japan, as a frequent earthquake country, has a responsibility to resolve efficient measures to enhance nuclear safety, to continue utilizing the nuclear power, based on the risks and importance levels in the scientific and rational manner. In his paper describes how to evaluate the risk of faults movement by engineering approach. An open fruitful discussion by experts in the various areas of earthquake, geology, geotechnical, civil, and a seismic design as well as other stakeholders such as academia prof...
英字タイトル:
Risk Evaluation Method for Faults by Engineering Approach (1) Nuclear safety for accident scenario and measures for fault movement