Corrosion Behavior of Si3N4 Ceramics under High-Temperature and High-Pressure Water Condition

2007 ◽  
Vol 26-28 ◽  
pp. 259-262 ◽  
Author(s):  
Weon Ju Kim ◽  
Seok Min Kang ◽  
Ji Yeon Park
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Grain Boundary ◽  
Corrosion Behavior ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Boundary Phase ◽  
Pressure Water ◽  
Si3n4 Ceramics

Silicon nitride (Si3N4) ceramics have been considered for various components of nuclear power plants such as mechanical seal of reactor coolant pump (RCP), guide roller for control rod drive mechanism (CRDM), and seal support, etc. Corrosion behavior of Si3N4 ceramics in high-temperature and high-pressure water must be elucidated before they can be considered for components of nuclear power plants. In this study, the corrosion behaviors of Si3N4 ceramics at hydrothermal condition (300°C, 9.0 MPa) were investigated in pure water. The grain-boundary phase was preferentially corroded and the corrosion reaction was controlled by the diffusion of the reactive species and/or products through the corroded layer. Results of this study imply that the variation of sintering aids and/or the control (e.g., crystallization) of the grain-boundary phase are necessary to increase the corrosion resistance of Si3N4 ceramics in high-temperature water.

The New Generation of High-Pressure Heaters for Steam Turbine Units at Nuclear Power Plants

2021 ◽  
Vol 68 (4) ◽  
pp. 285-294
Author(s):  
V. M. Zorin ◽  
A. S. Shamarokov ◽  
S. B. Pustovalov
Keyword(s):  
High Pressure ◽  
Steam Turbine ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
New Generation

scholarly journals Benefits, Drawbacks, and Future Trends of Brayton Helium Gas Turbine Cycles for Gas-Cooled Fast Reactor and Very-High Temperature Reactor Generation IV Nuclear Power Plants

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Arnold Gad-Briggs ◽  
Emmanuel Osigwe ◽  
Pericles Pilidis ◽  
Theoklis Nikolaidis ◽  
Suresh Sampath ◽  
...  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Optimum Operating ◽  
Future Trends ◽  
Design Point ◽  
Gen Iv ◽  
Very High

Abstract Numerous studies are on-going on to understand the performance of generation IV (Gen IV) nuclear power plants (NPPs). The objective is to determine optimum operating conditions for efficiency and economic reasons in line with the goals of Gen IV. For Gen IV concepts such as the gas-cooled fast reactors (GFRs) and very-high temperature reactors (VHTRs), the choice of cycle configuration is influenced by component choices, the component configuration and the choice of coolant. The purpose of this paper to present and review current cycles being considered—the simple cycle recuperated (SCR) and the intercooled cycle recuperated (ICR). For both cycles, helium is considered as the coolant in a closed Brayton gas turbine configuration. Comparisons are made for design point (DP) and off-design point (ODP) analyses to emphasize the pros and cons of each cycle. This paper also discusses potential future trends, include higher reactor core outlet temperatures (COT) in excess of 1000 °C and the simplified cycle configurations.

scholarly journals Corrosion Behavior of SUS 304 Stainless Steel in High Temperature and High Pressure Water Adding Metal Ions

1998 ◽  
Vol 47 (4) ◽  
pp. 275-279 ◽  
Author(s):  
Isao Sekine ◽  
Hiromi Sato ◽  
Yuka Imatamari ◽  
Naoki Mukaida ◽  
Makoto Yuasa ◽  
...  
Keyword(s):  
High Pressure ◽  
Stainless Steel ◽  
High Temperature ◽  
Metal Ions ◽  
Corrosion Behavior ◽  
304 Stainless Steel ◽  
Pressure Water

Determining the thermal power outputs of small high-temperature nuclear power plants

1976 ◽  
Vol 41 (6) ◽  
pp. 1076-1078
Author(s):  
A. I. El'tsov ◽  
A. K. Zabavin ◽  
Yu. A. Kotel'nikov ◽  
A. A. Labut ◽  
E. P. Larin ◽  
...  
Keyword(s):  
High Temperature ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Thermal Power ◽  
Power Outputs

Corrosion of Si3N4-Ceramics in Acids and Basics

2006 ◽  
Vol 45 ◽  
pp. 148-155 ◽  
Author(s):  
Jochen Schilm ◽  
Mathias Herrmann ◽  
G. Michael
Keyword(s):  
Silicon Nitride ◽  
Grain Boundary ◽  
Corrosion Behavior ◽  
Aqueous Media ◽  
Structural Features ◽  
Boundary Phase ◽  
The Subject ◽  
Corrosion Mechanisms ◽  
Si3n4 Ceramics ◽  
Made In

The corrosion behavior of silicon nitride materials in aqueous media strongly depends on the composition and amount of the grain boundary. But there exist no systematic investigations of the relation between the corrosion behavior and the composition and amount of the grain-boundary phase. The subject of this study is based on the evaluation of the corrosion mechanisms of Si3N4 ceramics and YSiAlON glasses, both with defined and characterized compositions, in acidic and basic environments with different concentrations. Special effort has been made in describing the compositions of grain boundary phases in the sintered Si3N4 ceramics. A model to describe structural features of YSiAlON-glasses was developed which allows the correlation of the corrosion behavior of the ceramics and the glasses with their compositions. In combination with SEM and TEM investigations it became possible to give structural reasons for the different observed corrosion mechanisms.

A Procedure for Determining the Safe Operation Time of Equipment and Pipelines Based on Nondestructive Testing Results

Vestnik MEI ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 11-17
Author(s):  
Dmitriy A. Kuz'min ◽  
◽  
Aleksandr Yu. Kuz'michevskiy ◽  
Artem E. Gusarov ◽  
◽  
...  
Keyword(s):  
High Pressure ◽  
Wall Thickness ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Operation Time ◽  
Safe Operation ◽  
Accelerated Corrosion ◽  
Equipment And Pipelines ◽  
Flow Accelerated Corrosion

The reliability of nuclear power plants (NPPs) has an influence on power generation safety and stability. The reliability of NPP equipment and pipelines (E&P), and the frequency of in-service inspections are directly linked with damage mechanisms and their development rates. Flow accelerated corrosion (FAC) is one of significant factors causing damages to E&P because these components experience the influence of high pressure, temperature, and high flow velocity of the inner medium. The majority of feed and steam path components made of pearlitic steels are prone to this kind of wear. The tube elements used in the coils of high pressure heaters (HPH) operating in the secondary coolant circuit of nuclear power plants equipped with a VVER-1000 reactor plant were taken as the subject of the study. The time dependences of changes in the wall thickness in HPH tube elements are studied proceeding from an analysis of statistical data of in-service nondestructive tests. A method for determining the initial state of the E&P metal wall thickness before the commencement of operation is proposed. The article presents a procedure for predicting the distribution of examined objects' wall thicknesses at different times of operation with determining the occurrence probability of damages caused by flow accelerated corrosion to calculate the time of safe operation until reaching a critical state. A function that determines the boundary of permissible values of the HPH wall thickness distributions is obtained, and it is shown that the intervals of in-service inspections can be increased from 6 years (the actual frequency of inspections) to 9 years, and the next in-service inspection is recommended to be carried out after 7.5 years of operation. A method for determining the existence of FAC-induced local thinning in the examined object has been developed. The developed approaches and obtained study results can be adapted for any pipelines prone to wall thinning to determine the frequency of in-service inspections (including an express analysis based on the results of a single nondestructive in-service test), the safe operation time, and quantitative assessment of the critical value reaching probability.

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