In this study, a structure of code and standard system for plant maintenance is discussed. And also where the guideline for leakage management, developed by the special research committee of Japan society of cenology (ISM), should occupy a position in the code and standard system is discussed. As a result of deration, it was concluded as follows. Iaintenance program for plant compone nts consists of two (2) parts, a regular program for dealing with ninor ageing and a special program for dealing with specif...
英字タイトル:
Study on the Position of Leakage Management Guideline in OM Code and Standard System

１．緒言 福島事故以降、原子力施設における核セキュリティの重要性は増大している。原子力発電所における核セキュリティの最大の目的は悪意のある行為者による原子力施設の安全機能の喪失のリスクを可能な限り下げることである。その中でも特に重要視すべきものが妨害破壊行為である。妨害破壊行為は一般的にアウトサイダーによるものとインサイダーによるものの2 つに分類される。現状の核セキュリティはアウトサイダーへの対応に比べインサイダーへの対応は十分とは言えない可能性がある。そのため原子力施設内でインサイダーが行う妨害破壊行......
英字タイトル:
Development of Dangerous Behavior Detection Method using Machine Learning

核セキュリティ脅威は現在進行形で多様化・巧妙化・拡大を続けているが、世界の核セキュリティ対策は、「新たな脅威」や「想定を超える脅威(BDBT; Beyond Design Based Threats)」に対し後れを取っている。...

近年の計算機性能の向上に伴い、人工知能（ Artificial Intelligence: AI）が目覚ましく進歩している。人工知能の分野の１つに機械学習 (Machine Learning)があり、さらに機械学習のなかの１つの分野が、深層学習 (Deep Learning)である。これら３つの関係を図示すると下のようになる。 このなかでも深層学習は、人間が自然に行っている学習能力と同様の機能をコンピュータで実現できるまで至っており、画像認識、音声認識、自然言語処理、リスク予測などの分野で大成功を収めつつある。 身近な例では、自動運転技術、画像認識技術や音声認識技術、自動音声応答技術など、さまざまな AI技術がすでに我々の身近に実用化されている。さらに原子力規制委員会は、ホームページ公開用の電力会社と職員との 「ヒアリング」の文字起こしに、この４月より音声自動認識 AIを活用し始めた。このように他産業における AI導入例は言わずもがな、規制にさえも遅れをとっている我が国の原子力産業はいつのまにか保守的な思考の虜になり、新技術導入に慎重になりすぎている可能性がある。さらには、どこにどのように AIを導入すれ...

現在のAI研究は各々の分野で閉じており、インターフェイスは皆無である。そこで、画像AIと自然言語処理AIとを、グラフ構造という共通のデータ形態を介して相関させる異種AIインターフェイスを提案し、そのための自動計算アルゴリズムを開発・実装した。...

Experiments that simulate bearing failures and the presence of cavitation are performed on a pump loop. During the experiments several types of data are acquired such as vibrations, system pressure, flow rate and motor current. A multivariate analysis is then applied to these data. Abnormalities are detected by evaluating the residual between the measured value and the estimated value that is determined from the model in a normal state. Because the influence of bearing failures is limited to a very loc...
英字タイトル:
Evaluation of a Multi-Sensors Condition Monitoring Method

Two magnetic methods are proposed for the evaluation of initial degradations of type 304 stainless steel in stress corrosion cracking (SCC). The first one is the measurement of the distribution of chromium depletion by means of a magnetic force microscope (MEM). MEM observations are performed for some samples sensitized in various conditions, and the obtained results coincide with the expected ones from the chromium behavior. Moreover, the phase distributions in the solution-annealed and sensitized states a...
英字タイトル:
Evaluation of Initial Degradation in Stress Corrosion Cracking by Magnetic Methods

Particularly, Since the on Fukushima the system Dai-ichi safety assessment accident, the of importance plants in operation, of “system the safety” various has degradation been recognized. aspects with transiti on of time ha been emphasized. Accordingly, functional degradation will be the assessment target, reliability and assessment the changes will in the be made safety on codes the consolidation and the concept of of important safety will functions be dealt under with; a where, system, the not on individ...
英字タイトル:
Lessons & Learns from Fukushima Daiichi Accident and New Concept of System Safety on Nuclear Power Plants

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 protectio...
英字タイトル:
Concept of System Safety on Operating Nuclear Power Plant

Since the Fukushima Dai-ichi accident, the importance of “system safety'' has been recognized anew. Particularly, system safety assessment of plants in operation from the various degradation perspectives, specifically, transition of time is very important. Accordingly, functional degradation will be the assessment target of degradation, and the changes in the safety standards and the concept of safety will be dealt with; where, the reliability assessment will be made on the consolidation of important func...
英字タイトル:
Study of System Safety Evaluation on LTO of National Project - Functional Degradation and System Safety Assessment of Nuclear Plants in Operation