第13回
原子力プラントにおけるレジリエンス評価法の開発 (その4:システム安全の考え方)
著者:
宮野 廣,Hiroshi MIYANO,出町 和之,Kazuyuki DEMACHI,鈴木 正昭,Masaaki SUZUKI,中村 隆夫,Takao NAKAMURA,釜谷 昌幸,Masayuki KAMAYA
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The total system design on Nuclear Plant ensures “Nuclear safety” with making practically achievable efforts to prevent and mitigate nuclear and radiological accidents. The performance based system design with “Defence in depth (D-I-D)” has been laid out as the key means in “preventing accidents”, “controlling escalation to serious consequences”, and “preventing harmful consequences to the public”. D-I-D is extended to the management of severe accidents, and is an approach intended to provide protection...
英字タイトル:
Development of Resilience Evaluation Method for Nuclear Power Plant (Part4: Concept of System Safety on Operating Nuclear Power Plants)
第9回
原子力発電所の配管減肉管理における局所減肉許容基準導入の検討
著者:
中村 隆夫,Takao NAKAMURA,茨 崇史,Takashi IBARA
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Pipe wall thinning caused by FAC (Flow Accelerated Corrosion) and LDI (Liquid Droplet Impingement)is managed through the measurement of pipe wall using UT (Ultrasonic Test) and the replacement of thinning element until reaching allowable limit in order to prevent pipe failure in Japan. Minimum wall thickness of design codes is applied to the allowable limit of pipe wall thinning management. On the other hand, the thinning area is localized in pipe wall caused by FAC and LDI, so the integr ity of piping sys...
英字タイトル:
Application of local thinning criteria in pipe wall thinning management of nuclear power plant
第10回
国内原子力発電所トラブル情報分析に基づく疲労損傷事象に対する安全性向上に関する検討について
著者:
松下 幹弥,Mikiya MATSUSHIMA,中村 隆夫,Takao NAKAMURA,新井 拓,Taku ARAI
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After Fukushima-Daiichi accident, nuclear power plants are highly requested to enhance safety against severe accident. It is important to prevent fatigue failure for operating nuclear power plants, especially pressure boundary of compon ts to ensure safety. This paper studies the failure database of nuclear power plant in Japan (NUCIA) and extracts the events caused by fatigue failure. Fatigue failure can be classified according to fatigue mechanism such as mechanical vibration, fluid vibration, high-cycl...
英字タイトル:
Study of fatigue failures to improve safety based on the analyses of failure database in Japanese nuclear power plant
論文
炉水環境中における疲労亀裂の 発生・成長挙動に及ぼす温度の影響
著者:
三澤 樹,Tatsuru MISAWA, 北田 孝典,Takanori KITADA, 中村 隆夫,Takao NAKAMURA, 竹田 敏,Satoshi TAKEDA, 釜谷 昌幸,Masayuki KAMAYA
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It has been clarified that the fatigue life is reduced in the fatigue test of high-temperature and high-pressure water that simulates PWR reactor coolant environment compared to that in the tmosphere, and temperature, strain rate,etc. affect the decrease of fatigue life. In this study, the influence of crack growth behavior on fatigue life of SUS316 in simulated PWR reactor coolant environment of different temperature was investigated. Fatigue tests were conducted under different temperatures (325℃ and 200℃...
英字タイトル:
Influence of Temperature on the Fatigue Crack Initiation and Growth in Reactor Coolant Environment
第16回
疲労き裂の発生・成長挙動に与える炉水環境中での温度の影響について
著者:
三澤 樹,北田 孝典,竹田 敏,中村 隆夫,(大阪大),釜谷 昌幸,(INSS)
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The fatigue tests were conducted under different temperature (325℃ and 200℃) in simulated PWR reactor coolant condition with interrupting tests and replica-observation. By observing fatigue crack on the specimen surface, the effect of temperature on crack initiation and growth were studied. From the results of the fatigue tests, the followings were confirmed; ・The number of cycles that fatigue cracks initiate is almost the same in different temperature. On the other hand, the number of cracks that initiate ...
英字タイトル:
Influence of Temperature on the Fatigue Crack Initiation and Growth in Reactor Coolant Environment
第11回
疲労健全性評価グランドデザインの構築(その 2) -国内実機疲労損傷事例分析-
著者:
中村 隆夫,Takao NAKAMURA,藤川 亮祐,Ryousuke FUJIKAWA,松下 幹弥,Mikiya MATSUSHITA,釜谷 昌幸,Masayuki KAMATA
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Abstract: After Fukushima-Daiichi NPP accident, improvement of nuclear safety is highly requested in order to prevent re-occurrence of severe accident. New sc me of fatigue evaluation to confirm system safety in NPPs is enhanced to be established based on Defense-in-Depth concept. In step 1, grand design of fatigue evaluation is reviewed on the viewpoint of fatigue management in long-term safe operation of NPPs, which is required after Fukushima-Daiichi NPP accident. Thi study focuses on the direction to r...
英字タイトル:
Reconstruction of Grand Design for Fatigue Evaluation (Step-2) -Fatigue failure analysis of Japanese NPPs-
第10回
疲労評価グランドデザインの新たな構築に向けて
著者:
中村 隆夫,Takao NAKAMURA,釜谷 昌幸,Masayuki KAMAYA
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Abstract: In this research, we investigate the issues of fatigue we have now and review Grand Design of fatigue evaluation on the basis of new role of fatigue anagement in plant long term operating scheme that is required after Fukushima daiichi NPP accident. ...
英字タイトル:
Reconstruction of Grand Design for Fatigue Evaluation
第11回
疲労試験片表面観察に基づく 微小き裂の発生・成長に与える環境効果の影響評価
著者:
藤川 亮祐,Ryosuke FUJIKAWA,阿部 茂樹,Shigeki ABE,中村 隆夫,Takao NAKAMURA,釜谷 昌幸,Masayuki KAMAYA
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Fatigue life of nuclear facilities tends to be decreased by the influence of reactor coolant, which is called environmental effect. The effect accelerates crack growth rate but the influence for cra ck initiation is not clarified. This study intends to discuss the environmental effect in crack initiation. The crack length and the number of cracks are measured from the investigation of fatigue t est specimens in reactor coolant and air. The behavior of crack initiation is revealed from the measurement of nu...
英字タイトル:
Evaluations of environmental effect on micro crack initiation and propagation by surface observations of fatigue specimens
第11回
膜圧式疲労試験による等二軸応力下での微小疲労き裂進展評価
著者:
飯田 智,Satoshi IIDA,阿部 茂樹,Shigeki ABE,中村 隆夫,Takao NAKAMURA,釜谷 昌幸,Masayuki KAMAYA
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1.はじめに 現在、原子力発電所においては経年劣化による設備の 機能喪失を防ぐため保全活動が行われている。プラント 機器の保全において疲労の累積を予測し損傷の防止を図 ることは事故防止につながる重要な活動である。疲労累 積評価は単軸試験で得たデータを基にして作成された設 計疲労曲線を用いて行われている。設計疲労曲線による 評価はもともと機器の設計に用いる目的で作られている ため、運転中の機器の実際の疲労累積状態や余寿命の評 価が難しいという課題がある。 そこで、実機の疲労累積状態を仮想的なき裂の長さに 置......
英字タイトル:
Evaluation of Micro Fatigue Crack Growth under Equi-biaxial Stress by Membranous Pressure Fatigue Test
第12回
試験片表面観察による機械構造用炭素鋼の 疲労き裂成長予測モデルの検討
著者:
石澤 輝士,Terushi ISHIZAWA,北田 孝典,Takanori KITADA,中村 隆夫,Takao NAKAMURA,釜谷 昌幸,Masayuki KAMAYA
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Cumulative Usage Factor (CUF) is currently used for fatigue design and management to prevent fatigue failure. Fatigue damage is evaluated by CUF but CUF doesn’t show the real extent of fatigue damage and cannot be used for probabilistic index for risk assessment. Therefore, in order to clarify relation between CUF and damage state, the introduction of postulated crack growth curve (P-curve) of stainless steel was examined by Kamaya [1]. This curve was defined by single crack growth curve made from fati...
英字タイトル:
Study on Fatigue Crack Growth Prediction Model of Carbon Steel based on Surface Observation of Fatigue Test Specimen