An improved method of FBR maintenance program by utilizing the risk-informed approach is discussed through investigation of RI-ISI implementation progr am. This paper presents current activities such as extraction of failure mod es and mechanisms in FBR plant, the risk index ,ranking criteria and so on....
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Study on Risk-Based Maintenance approach to FBR Plant

A Poisson distribution well represents SCC initiation and subsequent small scale growth in material tests. This report describ es the Poisson distribution application to LWR SCC database which was arranged from NUCIA. Frequencies were plotted against ope rated duration, then a Poisson's parameter was set to represent SCC aspect. In subsequent step, for one case of IASCC, a crack propagation was calculated. Fitting degrees of the distributions and a major parameter on failure probability were emphasized....
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Calculation of SCC detection and growth using a Poisson distribution

Furnace tubes are widely used in heat transfer device in petroleum or chemical industries. This study proposes an alternative calculation method for the evaluation of creep rupture damage factor of furnace tubes. The method is consistency with an evaluation procedure described in America n Petroleum Institute document API 581. Three types of creep parameters including Larson-Miller parameter, namely NRIM creep rupture data of fur nace tube material, can be applied for evaluation. The method is rather simpl...
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Damage Factor Calculation Method of Furnace Tube Creep Rupture in RBM

The insulation degradation can be appeared in cables which were installed at radiation and air environment in aged LWRs. It is implicated that the behavior is related to decrease of an antioxidant among the stabilizers which was caused by thermal oxidation and radiation induced oxidation. JNES has prepared a diagnostics method of insulation degradation for safety related low voltage cable used in aged LWRs.Th is paper shows a degradation indicator, for which nondestructive test and, then, probability of in...
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Reliability Aspect of Diagnostics Method of Cable Insulation for LWRs

The exhaust stack of Japan Materials Testing Reactor Hot laboratory is a part of gaseous waste treatment system. It was built in 1970 and is 40 m in height. In 2015, thinning was found at some anchor bolts on base of the stack. When thinning of anchor bolts were investigated, gaps between anchor bolt nuts and flange plate was found. JAEA removed steel cylinder of stack which is 33 m in height for safety. In the end of investigation, thinning was found in all anchor bolts of the stack. Cause investigation f...
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Cause investigation for thinning of anchor bolts and gaps between anchor bolt nuts and a flange plate at the JMTR hot laboratory exhaust stack

This study was performed to enrich the contents of measures for an ageing of t he nuclear power plants at Fukui area, where infrastructures of research works , for example, institutes, universities etc. are intensively existed., accordi ng to the Road-Map established by the Atomic Energy Society of Japan at 2005,...
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Research Program for Ageing of Nuclear Power Plant based on Characteristics of FUKUI Area

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