1．はじめに保全は、機械、電気、制御などの機器から成る、いわゆる「機械系」とそれを保全する「人間系」から構成されている。これまでの保全はこの２つの要素が渾然一体となって取り扱われ、両者を明確に分離して分析評価する手法が十分には取られて来なかった。これには社会的状況や規制などの影響もあったと考えられるが、いずれにしても保全の体系化や保全学の構築など、学術的アプローチを積極的に進めようとする気運が希薄であった。しかしながら、近年、保全を学術として捉え、それを体系化することによって、合理的効率的に保全の最適解が......

In this paper the virtual plant concept for optimization of maintenance in nuclear power plan t is proposed. The purpose of the virtual plant is the enhancement of accountability for gene ral public. Functions of virtual plant are discussed. They are the visualization of plant info rmation, the optimization of resource management, and the assessment of maintenance schedule....
英字タイトル:
Concept of Virtual Plant for Maintenance Optimization

Abstract Optimization of the replacement and/or inspection period of plant equipment is one of the main items to rationalize the activities on pla nt maintenance. In this study, we summarized the formulations to optimize the relpacement periods of equipment and/or parts based on the replacem ent policies. We also formulated the mathematical models for optimizing the inspection period of equipment. Then we numerically calculated the opt imum periods of the replacement and/or inspection for hypothetical equi...
英字タイトル:
Mathematical Approach to Rationalization of Maintenance Frequency

1. はじめに米国では、リスク概念を導入した確率論的安全評 価 (PSA) を原子力発電所の安全管理に利用し合理化を 進めている。ASME Section XI(維持規格) については、 すでに確率論を導入し合理的な保守管理に入っており、 Section II (設計・建設規格)についても、今後確率 論を導入した合理的な規格に改定していくことを計画 している。日本では、原子力配管設計においては、これまでASME Section IIを参考にして設計技術基準を定めてきた。 現行の ASME の手法は主に決定......
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Study on Prediction of Thickness in Nuclear Reactor Piping and Estimation of Inspection Intervals by Applying Reliability-base Method

This paper proposes a quantitative evaluation method of maintenance plan for nuclear power plants, developed by introducing the scientific approach, and also proposes a method to search an optimum maintenance plan to be obtained by maximizing nuclear safety and economic efficiency simultaneously, then balancing them. As a result of consideration, the following results were obtained. (1) The quantitative evaluation methodology for optimizing maintenance plan for nuclear power plants was developed. (2) ...
英字タイトル:
Study of Optimization of Maintenance Plan for Nuclear Power Plants

This paper discusses maintenance optimization in maintenance implementation stage following maintenance planning stage in nuclear power plants and proposes a methodology to get an optimum maintenance work plan. As a result of consideration, the followings were obtained. (1) The quantitative evaluation methodology for optimizing maintenance work plan in nuclear power plants was developed. (2) Utilizing the above methodology, a simulation analysis of maintenance work planning for BWR's PLR and RHR syste...
英字タイトル:
Study on Optimization of Normal Plant Outage Work Plan for Nuclear Power Plants

A research project in ASME is developing a technical basis for reliability-based load and resistance factor design (LRFD) methods for piping in nuclear power plant. In LRFD, the probabilistic properties of load and resistance of components are taken into considerati on. There are several advantages in LRFD methods comparing to the traditional design methods based on the deterministic theory. In th is document theoretical basis of LRFD is discussed and the present research progress in ASME is reviewed based...
英字タイトル:
Load and Resistance Factor Design For Piping of Nuclear Power Plant

This work investigates the effective method for detecting structural abnormality such as misalignment or unbalance in rotating machines. Experiments are performed which acquire vibration acceleration data of a horizontal pump under various structural abnormality. In order to detect abnormality comparing to the normal state, feature vector is defined as a set of magnitude of rotational frequency and its harmonics of vibration signal, then change of it is evaluated with SBM (Similarity Based Modeling). W...
英字タイトル:
Study of the capability of detection of structural abnormality in rotating machines with multipoint analysis

In order to investigate effective methods to detect the abnormality of pipe supports, vibration data of piping was acquired under various operating pressure and conditions of supports. Single feature value such as RMS of vibration acceleration, vibration velocity, vibration displacement, was not always able to detect the abnormality. To make the feature value more informative, the feature vector was defined as the combination of 3 aforementioned feature value. Then the difference of feature vectors compa...
英字タイトル:
Multivariate analysis method to detect abnormality of pipe supports

In the present study, effect of spurious diagnostics to improvement of safety, and po ssibility of extension in the interval of TBM (Time-Based Maintenance) by introducing CBM (Condition-Based Maintenance) and necessity of TBM were investigated. From these investigations, improvement of safety and reduction of maintenance cost can be seen....
英字タイトル:
Study on Best-Mix of CBM and TBM Considering Effect of Spurious Diagnostics Using State Transition Model