Baffle Former Bolts (BFBs) in PWR nuclear plant have the possibility to be cracked due to Irradiation Assisted Stress Corrosion Cracking (IASCC). The maintenance guideline for BFBs had been established from Thermal and Nuclear Power Engineering Society in 2000, and BFBs have been maintained in accor dance with this maintenance rules. Recently, the new edition of this guideline has been published in order to reflect latest IASCC data and more preci se stress evaluation of BFB into maintenance rules. The su...
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Improvement activities for the maintenance of Baffle Former Bolts

Japanese utilities have been conducting in-service inspection to assure integrity of nuclear power plant components in compliance with JSME fitness for service code. The JSME fitness for service code prescribes inspection intervals of the components corresponding to the importance of safety function and also it has been constantly updated reflecting operating experience such as leakage events and so on. In order to contribute effective maintenance activities including in-service inspections, it is desire...
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In-service Inspection of Nuclear Power Plant

In order to reutilize nuclear power generation and maintain their presence, it is important to take actions based on assumptions beyond "safety myth". For example, in the field of SCC, long term reliability may be further assured based on evaluation under severer condition than the usual operating environment. Since such severe conditions cannot be reasonably simulated by the experiment in the laboratory, it is effective to utilize numerical simulation as reported in the previous paper. This paper rep...
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Development of an evaluation method utilizing numerical simulation to assure long-term reliability of residual stress improvement by surface treatment

The guideline committee for the inspection and evaluation of Reactor Vessel Internals of JANSI (Japan Nuclear Safety Institute) has been developing many guidelines based on principle which the conservative methodology, and covered both individual inspection method of reactor internals and application of repair methods for reactor internals. In this paper, some aspects of the JANSI-VIP-21 (Guidelines for the inspection and evaluation of Reactor Vessel Internals, revised Mar.2017) which is summary document o...
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Outlines of Guidelines for the Inspection and Evaluation of Reactor Vessel Internals

“The guideline committee for the inspection and evaluation of Reactor Vessel Internals” of JANSI (Japan Nuclear Safety Institute) has been developing many guidelines based on principle which the conservative methodology, and covered both individual inspection method of reactor internals and application of repair methods for reactor internals. In this paper, some aspects of the JANSI-VIP-03 (Guidelines for the inspection and evaluation of Reactor Vessel Internals, revised Dec.2013) which is summary docu...
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Outlines of Guidelines for the Inspection and Evaluation of Reactor Vessel Internals

In this study, a fast simulation technique of Iterative Substructure Method (ISM) was applied for numerical analysis of the distribution of residual stress by J-weld and repair weld of Bottom Mounted Instrument (BMI) nozzle in reactor vessel penetration. The calculated results were compared with the measured values to validate the constructed residual stress analysis model. The effect of BMI mounting angles on distribution of residual stress at J-welds was investigated. Based on the results, similarity and...
英字タイトル:
Numerical Analysis of Residual Stress by J-weld and Repair Weld of Bottom Mounted Instrument Nozzles in Reactor Vessel Penetration