次世代高速炉の合理的な設計や保全の最適化を実現するためには，もんじゅにおける点検長期化の要因を分析し，課題の整理と対策案を検討することが重要となる．本論文では，高速炉の稼働率向上を目的に，保全合理化検討のための概略的分析の結果を報告する． 具体的には，もんじゅの保全に関する全体傾向の把握及び保全合理化の余地が大きいと考えられる保全内容を抽出するため，もんじゅ保全計画に記載されている点検タスクの情報を分析した．また，得られた分析結果に対し，保全合理化の提案を行った．...
英字タイトル:
Proposal of Maintenance Rationalization for Next-Generation Fast Reactors based on the Analysis of the Prolonged Maintenance of the Prototype Fast-Breeder Reactor in Japan, “Monju” (2) ～Analysis of Maintenance Plan of “Monju” in Reactor Cold Shutdown～

本論文では、点検自体の期間も長く、その遅延が直接プラント工程に影響を及ぼすクリティカルパスの点検に着目し、もんじゅの点検に要する期間が長期化した要因を分析する。この要因に対し、次世代高速炉における合理的な保全を実現し、稼働率を向上させることを目的とした、次世代高速炉の設計や運用に反映すべき対策を検討した。...
英字タイトル:
Proposal of Maintenance Rationalization for Next-Generation Fast Reactors based on the Analysis of the Prolonged Maintenance of the Prototype Fast-Breeder Reactor in Japan, “Monju”? (1) ～Analysis of Plant Schedule of “Monju” in Cold Shutdown～

Probabilistic fracture mechanics (PFM) evaluation requires information on the probabilistic distributions of the number and size of initial defects, material properties such as crack growth rate due to fatigue and creep, and load to evaluate the failure probability of components. In this study, ultrasonic testing was conducted on the welds of the test equipment used in the research and development of fast reactors, and the number and size of defects were evaluated. The results could be used as conservative ...
英字タイトル:
Evaluation of Defect Number Density in Sodium Equipment Stainless Steel Welds

If components can be maintained according to a target reliability of nuclear power plants, plant safety and economic efficiency could be improved by avoiding excessive or insufficient margins. This approach can rationalize the maintenance of low target reliability components and concentrate resources (people, money, and time) on the maintenance of high target reliability components. It would take a long time to evaluate the target reliability for all components in the plant by quantitatively using probabili...
英字タイトル:
Proposal of a Simple Screening Method Which Determines Necessity of Quantitative Risk Assessment for Maintenance Rationalization Using Risk Information

In this paper, we propose a new method for extracting design issues on maintenance. Maintenance periods might be prolonged due to design issues. In the proposed method, maintenance preconditions are extracted by organizing the design information. A maintenance schedule is created by using extracted maintenance preconditions. If the created maintenance schedule doesn't achieve target periods, design issues could be extracted from the viewpoint of maintenance precondition. A simple example using "Monju" desig...
英字タイトル:
Proposal of a Method of Extracting Design Issues on Maintenance for the Rational Design of Next-Generation Reactors

JAEA has started the development of Advanced Reactor Knowledge-and AI-aided Design Integration Approach through the whole plant lifecycle (ARKADIA) that performs integrated design evaluation and optimization from various viewpoints such as safety, economy, and maintainability using risk information, in order to dramatically improve the development efficiency of innovative reactors. In this paper, we report the concept of a knowledge management system to support integrated design evaluation and optimization,...
英字タイトル:
Development of knowledge management system contributing to integrated design evaluation and optimization of innovative reactors

(Times New Roman 10pt) should be about 150 words. How to use the real materials of the Nuclear Power Plant during decommissioning stage are studied and discussed for a research of ageing management for safe long term operating. Moreover the real structural materials of “Fugen” Power Station during decommissioning stage has been performed to study for the research of ageing management. ...
英字タイトル:
Research of using structural materials of decommissioning Nuclear Power Plant for technical evaluation of ageing management for safe long term operating

In order to achieve both safety and economic efficiency of a nuclear power plant, it is necessary to realize rational maintenance based on characteristics of the plant. The fast breeder prototype reactor, Monju, spent most of the year for the maintenance. It is important to identify causes of the prolonged maintenance of Monju and to investigate countermeasures for implementation of rational maintenance of a next fast reactor. In this study, causes of the prolonged maintenance of Monju during reactor cold s...
英字タイトル:
Analysis of issues related to maintenance period of the fast breeder prototype reactor Monju (1) Analysis of plant operation for maintenance of cold shutdown Monju

In order to achieve both safety and economic efficiency of a nuclear power plant, it is necessary to realize rational maintenance based on characteristics of the plant. The fast breeder prototype reactor, Monju, spent most of the year for the maintenance. It is important to identify causes of the prolonged maintenance of Monju and to investigate countermeasures for implementation of rational maintenance of a next fast reactor. In this study, causes of the prolonged maintenance of Monju during reactor cold s...
英字タイトル:
Analysis of issues related to maintenance period in the fast breeder prototype reactor Monju (2) Analysis of plant maintenance plan

To achieve the reasonable and effective maintenance of nuclear power plants, it is essential to optimize the aging management from the viewpoints of both safety and efficiency. We propose an inspection-process-scheduling model that minimizes the number of inspection activities in a fast reactor. In this study, we formulate the inspection-process-scheduling problem as mixed integer programming and 0- integer programming problem....
英字タイトル:
Fundamental Study on Optimal Scheduling of Inspection Process for Fast Reactor