Abstract This paper discusses the possibility of in-situ evaluation of crack propagation using Eddy Current Monitoring (ECM) system in a Boiling Water Reactor (BWR) environment. For the purpose, an ECM experiment was conducted at the System Safety Benchma rk Facility (SSBF). The target for the monitoring was a large-scale pipe specimen made of austenitic stainless steels 304L, 316L, and carbon steel STS410, connected by weld joints of nickel based alloy 182. Slits were prepared at the Heat Affected Zones (...
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In-situ Crack Evaluation using Eddy Current Monitoring in a Boiling Water Reactor Environment

By incorporating the film slip-dissolution/oxidation model and the elastic-plastic finite element method (EPFEM), the effect of the over load on stress corrosion cracking (SCC) growth rate of stainless steel in high temperature water is discussed in this paper. Results sho w that SCC growth rate of a 20% cold worked 316L stainless steel in high temperature water decrease in the overload affected zone ahead of the growing crack tip. Therefore, a reasonable overload could availably reduce the SCC growth rat...
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Effect of Overload on SCC Growth in Stainless Steels in High Temperature Water

The effects of electrochemical parameters in terms of electrochemical potential on stress corrosion cracking growth rates of au stenitic stainless steels in high temperature pure water are analyzed based on obtained experimental results and reported data. The effect of decreasing electrochemical potential is more significant in non-hardened sensitized and non-hardened stainless s teels than that in strain-hardened stainless steels, which is also supported by the results of Ni-base alloys and weld metals....
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Effects of Electrochemical Parameters on SCC of Stainless Steels inSimulated BWR Environments

The effect of scratches on oxidation evolution of Alloy 600 was monitored by EIS in 290A°C simulated primary water. EIS result indicates that oxide film reached a stable condition until 7 days' immersion. The scratched Alloy 600 possessed almost the same evolution of oxide film with plain specimens. Anodic polarization was pe rformed to study combined effect of scratches and charged hydrogen. The anodic current changes of scratched A lloy 600 after hydrogen charging were not the simple superimposition bet...
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Electrochemical response of scratched Alloy 600 in simulated primary waterand its influence with hydrogen entry

A Proactive Materials Degradation Management (PMDM) project has been carried out at the Frontier Research Initiative (FRI), New Industry Creation Hatchery Center, Tohoku University for 5 years, as a part of a Nuclear Industries Safety Agency (NISA, now the Secretariat of the Nuclear Regulation Authority) project that was originally formed in 2007 to define an Aging Management Program that addresses unexpected structural material failures in Light Water Reactors (LWRs). Such a program required, therefor...
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Proactive Evaluation of Potential and Latent Materials Degradation Phenomena by PIRT

In order to improve the understanding of the effect of dissolved hydrogen (DH) on the property of oxide film in high temperature water, the electronic properties of the oxide film on Alloy 600 in hi gh temperature water under various levels of DH were studied by contact electric resistance (CER) technique and electrochemical impedance spectroscopy. The results showed that the oxide film exhibit ed n-type semiconductivity. The film resistance, charge transfer resistance and ionic defect transport resistance...
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Investigation of the Effect of Dissolved Hydrogen on the Oxide Film on Alloy 600 in HighTemperature Water by In-situ Electrochemical Techniques

This study investigates the anodic behavior of Alloy 690 thermal treated (TT) in Pressurized Water Reactors (PWRs) primary water at 290°C, 9 MPa by means of polarization measurement, electrochemical impedance spectroscopy (EIS) and X-ray photoelect ron spectroscopy (XPS) analysis. Experimental results of hydrogen charged and uncharged Alloy 690TT show that hydrogen increases anodic steady current density and decreases capacitance loop, which implies that charged hydrogen changes the electroch emical proces...
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?The anodic behavior of Alloy 690 in simulated PWR primary water at 290°C

This study proposes an innovative technique for repairing of cracked or damaged parts of structures, such as nuclear or thermal power plants, by means of cold gas dynamic spray (CS) technique. In the case of generation of cracks etc, in the structure, the cracks can be repaired by welding. However, the welding spends considerable time on repair, and also needs special skills. The CS techni que is known as a new technique not only for coatings but also for thick depositions. It has many advantages, i.e. ...
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Fundamental Study on Repairing Technique for Cracked or Damaged Parts of Structuresby Cold Gas Dynamic Spray Technique

A Proactive Materials Degradation Management (PMDM) project has been carried out at the Fronti er Research Initiative (FRI), New Industry Creation Hatchery Center, Tohoku University for 5 ye ars, as a part of a Nuclear Industries Safety Agency (NISA) project that was originally formed in 2007 to define an Aging Management Program that addresses unexpected structural material fa ilures in Light Water Reactors (LWRs). Such a program required, therefore, the development of a life prediction capability for sp...
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Proactive Evaluation of Potential/Latent Degradation Phenomena for Light Water Reactor Structural Materials and System Safety

The predictive and preventive maintenance technologies are of increasingly importance for the long term operation (LTO) of Light Water Reactor (LWR) plants. In order f or the realization of LTO, it is essential to prevent the degradation phenomena from emergence using proper maintenance programs on foreseeing the phenomena and evalua ting their rates of development. In this paper, the proactive activities and the aging degradation phenomenon which were discussed in the Proactive Aging Management Gro up Mee...
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Proactive Materials Degradation Management and Development ofCondition Monitoring Technology