1F事故以前のように「原子力安全は安全の専門家に任せておけばよい。」といった他人事では許されない時代が来た。今後は全ての原子力関係者が原子力安全を理解しそれを常識化する必要がある。本稿ではそのための方策を提案する。...

The PIRT process was developed as a part of the systematic and documented means of demonstrating the validation of best estimate simulation codes in USNRC licensing of nuclear power plants. In this paper the PIRT process was applied for finding influential factors giving an impact on the accuracy of ultrasonic testing and eddy current testing and related problems required to improve the accuracy and also reports the results that the problems were ranked from the viewpoint of importance, knowledge and c...
英字タイトル:
Accuracy of Non-destructive Examination Techniques to Detect Fatigue Crack

The New regulatory standards for nuclear power plants (NPPs) in Japan were strengthened, based on the lessons learned from the Fukushima Daiichi accident. At first glance, it seems that they mainly require improvements in the hardware of NPPs. Of course, improving safety by hardware is very important and needs to be continued. However, on the other hand, improving safety by software or human ware is also very important. Therefore, active discussions have been held on software and/or human ware in internatio...
英字タイトル:
Can we say that the Safety Measures Taken after the Fukushima Daiichi Accident are Sufficient? (Issues Considered Important for Improving Safety)

１．はじめに 　原子力発電所は膨大な数の機械、電気、制御、土木建築の各種機器･構造物から成っており、安全機能をはじめとする多くの機能や性能を発揮し発電している。このハードウェア・システム（ここではこれを総称して「機械系」という。）は深層防護や系統･機器の多重性/多様性/独立性の他、フェイルセーフやフールプルーフ、インターロックなどの各種の安全設計が施されており、機械系として一定の信頼性を確保できるようになっており、その結果として安全性を確保できるようになっている。しかしながら、これだけでは十分でなく、機械系が予め付与された機能/性能を発揮できるように原子力発電所の組織･要員（ここではこれを総称して「人間系」という。）によって運転や保全をはじめとする保安活動が適切に行われてはじめて安全が確保されるようになっている。（図1） ...

The latest trends related to standardization and optimization of US nuclear power plant maintenance are explained as follows, including the history from the past. Standard nuclear performance model (SNPM) of power plants started in the late 1990s. Standardization of maintenance process by TNPO AP-913 "Equipment Reliability" and AP-928 "Work Management" and maintenance optimization by EPRT PM (Preventive Maintenance) Template and PMBD. Critical component reduction and Value Based Maintenance (VBM) as the lat...
英字タイトル:
Standardization and Optimization of Maintenance at US Nuclear Power Plants

For creating a corrective measure plan for industrial plant components, it is very important to have a well-grounded basis. Therefore, this paper proposes a method for determining the following three elements of such a plan: an equipment to be repaired, a corrective measure method to be adopted, and a timing of its implementation using a rational approach. And the importance of corrective measure in plant maintenance is also discussed. ...
英字タイトル:
Codes and Standards in Repair and Replacement Process .Importance of Corrective Action in Maintenance Activities

While the importance of maintenance of NPP is now being well recognized, standardization on maintenance has been mainly implemented for hardware that is SSCs. The quality of the SSCs in service is ensured not only by recognition of physical characteristic of the SCCs, but also by activities of the organization and personnel for maintenance of the SSCs. This paper presents status of study on the guideline for management of repair activities, which provides a typical example of standardization on management o...
英字タイトル:
The Study on the Guideline for Management of Repair Activities

Working Group on Application Enhancement of Repair Replacement Technology has been established since September 2015, for the purpose of studying specific measures to create an environment that Japanese utilities can easily make corrective actions such as repair replacement technology applicable to Nuclear Power Plant to improve the safety of their own plants, and meetings have been held five times until the end of April 2016. In this paper, discussions on the WG meetings so far are shown, as well as th...
英字タイトル:
Current Status of WG on Application Enhancement of Repair Replacement Technology

This paper discusses maintenance optimization by the automatic planning tool for regular plant outage work in nuclear power plant using the logic programmin g language “Prolog”. As a result of consideration, the following results were obtained. (1) The automatic planning tool for regular plant outage in nuclear power plant was developed. (2) Using this tool, the work plan for BWR primary recirculation system and residual heat removal systemwas automatically made on the condition of flattening man loading o...
英字タイトル:
A Study on Maintenance Optimization by the Automatic Planning Tool for Regular Plant OutageWork in Nuclear Power Plant Using the Logic Programming Language “Prolog”

軽水炉炉内構造物の点検評価ガイドラインの体系化 山下 裕宣,酒井 和夫,青木 孝行......