Evaluation Methods for Corrosion Damage of Components in Cooling Systems of Nuclear Power Plants by Coupling Analysis of Corrosion and Flow Dynamics (I)

Naitoh, Masanori; Uchida, Shunsuke; Koshizuka, Seiichi; Ninokata, Hisashi; Hiranuma, Naoki; DOSAKI, Koji; Nishida, Koji; Akiyama, Minoru; Saitoh, Hiroaki

doi:10.1080/18811248.2008.9711900

Cited by 12 publications

(13 citation statements)

References 20 publications

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“…7) This meant that the finally estimated lifetime for each component was less than twice the actual lifetime or larger than half the actual lifetime. When the estimated lifetime is shorter than 5 years, the component should be inspected carefully, and when it is shorter than 2 years, it should be immediately replaced.…”

Section: Target Accuracy Of Wall Thinning Evaluationmentioning

confidence: 99%

“…The complex flow pattern which enhances FAC should be analyzed by a combination of 1D, 2D, and 3D CFD codes (PLASHY). 7,13) In order to obtain precise flow velocity distributions at the inner surface on the large scale pipes applied at power plants, 2-3D k-" methods supported with wall functions were applied.…”

Section: Mass Transfer Coefficientsmentioning

confidence: 99%

“…Previous papers have outlined evaluation methods for corrosion damage of components in cooling systems of nuclear power plants by coupling analyses of corrosion and flow dynamics 7) and evaluation methods for corrosion conditions along the flow path 8) based on hydrazine-oxygen (N 2 H 4 -O 2 ) reaction analysis. From them, wall thinning rate evaluation procedures based on a coupled FAC model of a static electrochemical analysis and a dynamic oxide layer growth analysis 9) were proposed.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation Methods for Corrosion Damage of Components in Cooling Systems of Nuclear Power Plants by Coupling Analysis of Corrosion and Flow Dynamics (IV) Comparison of Wall Thinning Rates Calculated with the Coupled Model of Static Electrochemical Analysis and Dynamic Double Oxide Layer Analysis and Their Values Measured at a PWR Plant

Uchida

Naitoh

Uehara

et al. 2010

Journal of Nuclear Science and Technology

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In order to confirm applicability and accuracy of FAC evaluation methods based on the coupled FAC model of static electrochemical analysis and dynamic oxide layer growth analysis, wall thinning rates calculated with the proposed methods were compared with those measured for the secondary piping of a PWR plant. Distributions of flow velocity and temperature along the whole system were calculated with 1D and 2D computational flow dynamics (CFD) codes and corrosive conditions were calculated with a N 2 H 4 -O 2 reaction analysis code. Precise flow turbulence at major parts of the system was analyzed with 3D CFD codes to obtain mass transfer coefficients at structure surfaces. Then, wall thinning rates were calculated with the coupled FAC model by applying the mass transfer coefficients. Comparison of the calculated and measured results led to the following conclusions. 1) Structures with complicated geometry in the plant, e.g., the pair of a bend pipe and a valve, could be simplified as a combination of pipes for the calculation.2) Flow distribution calculated with 3D CFD codes for a large-scale piping system could be extrapolated to those at the very surface of the piping to obtain a precise distribution of mass transfer coefficients at the region of interest.3) Wall thinning rates calculated by applying the obtained mass transfer coefficients agreed with the measured rates within a factor of 2.4) The effects of flow turbulence were transferred through a distance of more than 5 times the pipe diameter from the original turbulent point, but the effects on wall thinning rate were negligibly small.

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Section: Target Accuracy Of Wall Thinning Evaluationmentioning

confidence: 99%

Section: Mass Transfer Coefficientsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Evaluation Methods for Corrosion Damage of Components in Cooling Systems of Nuclear Power Plants by Coupling Analysis of Corrosion and Flow Dynamics (IV) Comparison of Wall Thinning Rates Calculated with the Coupled Model of Static Electrochemical Analysis and Dynamic Double Oxide Layer Analysis and Their Values Measured at a PWR Plant

Uchida

Naitoh

Uehara

et al. 2010

Journal of Nuclear Science and Technology

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“…The major parameters 13,15,16,29) to determine FAC are divided into material parameters, flow dynamics parameters, and environmental parameters.…”

Section: Major Parameters To Determine Fac and Ldimentioning

confidence: 99%

“…13) In Ref. 13), the approaches adopted in the project are presented in detail. The countermeasures to mitigate corrosive conditions in secondary cooling systems at PWRs were proposed and examined under the conditions of an actual NPP.…”

Section: Introductionmentioning

confidence: 99%

Evaluation Methods for Corrosion Damage of Components in Cooling Systems of Nuclear Power Plants by Coupling Analysis of Corrosion and Flow Dynamics (V) Flow-Accelerated Corrosion under Single- and Two-phase Flow Conditions

Okada

Uchida

Naitoh

et al. 2011

J. Nucl. Sci. Technol.

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The characteristics of flow-accelerated corrosion (FAC) in the wide sense are overviewed. Overlapping effects of flow dynamics and corrosion are important issues to determine the reliability and lifetime of major structures and components of light water reactor plants. FAC in single-and two-phase flows and liquid droplet impingement (LDI) in two-phase flow are typical phenomena due to both interactions. In order to evaluate local wall thinning due to FAC and LDI, a 6-step evaluation procedure for each has been proposed.(1) For FAC wall thinning evaluation, corrosive conditions along the flow path and mass transfer coefficients at the structure surface under single-and two-phase flow conditions were calculated to evaluate high-risk zones for FAC occurrence, and then wall thinning rates were calculated with the coupled model of static electrochemical analysis and dynamic oxide layer growth analysis at the identified high-FAC-risk zones.(2) For LDI local wall thinning evaluation, trajectories of liquid droplets in high-velocity steam, their collision densities and velocities on the pipe inner surface were calculated to evaluate high-risk zones for LDI occurrence, and then local wall thinning rates were calculated at the identified high-LDI-risk zones. For the region with steam velocity higher than 200 m/s, the wall thinning rate was determined mainly by erosion (LDI (erosion)), while for that with velocity lower than 100 m/s, it was determined by corrosion (LDI (corrosion)).(3) The FAC wall thinning model was applied for two-phase flow as well as single-phase flow, while the FAC wall thinning model was applied for LDI (corrosion). The empirical formula was applied for LDI (erosion) after discriminating LDI (corrosion) and LDI (erosion) based on steam velocity and quality.

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Upconversion Luminescent Material‐Based Inorganic‐Organic Hybrid Sensing System for the Selective Detection of Hydrazine in Environmental Samples

et al. 2018

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Hydrazine is a noxious environmental pollutant, which can be easily absorbed through skin, respiratory and oral paths of exposure and leads to mutagenic and carcinogenic diseases, which demands for the progress of advanced detection methods. In this regard, we report a new detection platform based on luminescence resonance energy transfer (LRET) for the detection of hydrazine (N 2 H 4 ) in environmental samples, where anti-Stokes shift luminescence having optical sensing system is built with upconversion nanophosphors (UCNPs, donor) modified by resorufin propionate (RePr, acceptor). Herein UCNPs were used as an excitation host to significantly minimize the photobleaching of RePr. Upon interaction with N 2 H 4 , the green upconversion luminescence (UCL) intensity of hybrid nanoprobes (RePr-UCNPs) gradually decreases, since the green emission is in resonance with the absorbance of resorufin, whereas the red emission intensity was intact. Hence, green emitting optical sensing system shows red luminescence in the presence of hydrazine. This organic-inorganic hybrid sensing system has been utilized for the sensing of hydrazine in various environmental samples and the obtained results are compared with the sensing efficiency in distilled water. This anti-Stokes shift luminescent hybrid sensing system would be a promising candidate to be utilized in environmental protection, water treatment and safety inspection.

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Evaluation Methods for Corrosion Damage of Components in Cooling Systems of Nuclear Power Plants by Coupling Analysis of Corrosion and Flow Dynamics (I)

Cited by 12 publications

References 20 publications

Evaluation Methods for Corrosion Damage of Components in Cooling Systems of Nuclear Power Plants by Coupling Analysis of Corrosion and Flow Dynamics (V) Flow-Accelerated Corrosion under Single- and Two-phase Flow Conditions

Upconversion Luminescent Material‐Based Inorganic‐Organic Hybrid Sensing System for the Selective Detection of Hydrazine in Environmental Samples

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