scholarly journals Simulation of Porous Magnetite Deposits on Steam Generator Tubes in Circulating Water at 270 °C

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 729
Author(s):  
Soon-Hyeok Jeon ◽  
Hee-Sang Shim ◽  
Ji-Min Lee ◽  
Jeoh Han ◽  
Do Haeng Hur
Keyword(s):  
Steam Generator ◽  
Loop System ◽  
Pressurized Water ◽  
Accelerated Corrosion ◽  
Heating Source ◽  
Circulating Water ◽  
Research Fields ◽  
Water Reactors ◽  
Heat Transfer Degradation ◽  
Deposition Test

In the secondary side of pressurized water reactors (PWRs), the main corrosion product accumulated on the steam generator (SG) tubes is magnetite, which has a porous structure. The purpose of this work is to simulate the porous magnetite deposited to the SG tubes using a loop system. We newly developed a circulating loop system for a porous magnetite deposition test. A test section was designed as a single hydraulic flow channel, and a cartridge heater was fabricated and mounted into a commercial SG tube to provide an equal heating source for the primary water. After the deposition test, the simulated magnetite deposits were characterized for comparison to real SG tube deposits collected from an operating PWR plant. The magnetite deposits produced using the loop system were appropriate for simulating the real SG tube deposits because the particle characteristics, phase, and porous morphology are closely similar to those of real deposit samples. Using the loop system, the chemical impurities such as Na and Cl can be easily concentrated within the pores of the simulated magnetite deposits. These simulated magnetite samples are expected to be widely utilized in various research fields such as the heat transfer degradation and magnetite accelerated corrosion of SG tubes.

U.S. Operating Experience With Thermally Treated Alloy 600 Steam Generator Tubes

2002 ◽  
Author(s):  
April Smith ◽  
Kenneth J. Karwoski
Keyword(s):  
Steam Generator ◽  
Operating Experience ◽  
Alloy 600 ◽  
Steam Generators ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Water Reactors ◽  
1960S And 1970S ◽  
The 1960S ◽  
Thermally Treated

Steam generators placed in service in the 1960s and 1970s were primarily fabricated from mill-annealed Alloy 600. Over time, this material proved to be susceptible to stress corrosion cracking in the highly pure primary and secondary water chemistry environments of pressurized-water reactors. The corrosion ultimately led to the replacement of steam generators at numerous facilities, the first U.S. replacement occurring in 1980. Many of the steam generators placed into service in the 1980s used tubes fabricated from thermally treated Alloy 600. This tube material was thought to be less susceptible to corrosion. Because of the safety significance of steam generator tube integrity, this paper evaluates the operating experience of thermally treated Alloy 600 by looking at the extent to which it is used and recent results from steam generator tube examinations.

An Automated System for Detection of Through-Wall Cracks in Racks in Steam Generator Tubes

2005 ◽  
Vol 297-300 ◽  
pp. 2071-2076 ◽  
Author(s):  
Sung Jin Song ◽  
Chang Hwan Kim ◽  
Deok Hyun Lee ◽  
Myung Sik Choi ◽  
Do Haeng Hur ◽  
...  
Keyword(s):  
Steam Generator ◽  
Automated System ◽  
Pressurized Water ◽  
Promising Tool ◽  
Primary Water ◽  
Water Reactors ◽  
The Difference ◽  
Human Operators ◽  
Shape Curve ◽  
Steam Generator Tubes

Through-wall axial cracks occurred by primary water stress corrosion are one of the serious defects in steam generator (SG) tubes (made of alloy 600) in pressurized water reactors. Therefore, it is necessary to detect and size them by eddy current testing (ECT) conducted during in-service inspection of SG tubes. To address this issue, it has been recently proposed an effective method, namely „M-shape profile“ approach, which relies on the difference in the amplitude between the pancake and plus point coils in a MRPC probe. Even though the M-shape curve approach is straightforward in principle, it requires time-consuming data processing if performed by human operators. In order to get rid of this tedious task, an automated system is developed in the present work. This paper addresses the principle of the M-shape approach together with the automated system and its performances for the detection of natural axial cracks in SG tubes. The results observed in the present work demonstrate the high potential of the developed system as a very promising tool for detecting through-wall cracks in many practical field applications.

scholarly journals Micro-Galvanic Corrosion of Steam Generator Materials within Pores of Magnetite Flakes in Alkaline Solutions

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 899 ◽  
Author(s):  
Soon-Hyeok Jeon ◽  
Geun Song ◽  
Do Hur
Keyword(s):  
Steam Generator ◽  
Galvanic Corrosion ◽  
Area Ratio ◽  
Corrosion Products ◽  
Alkaline Solutions ◽  
Galvanic Coupling ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Alloy 690 ◽  
Water Reactors

In secondary coolant system of the pressurized water reactors, the reduced corrosion products such as metallic Cu and Pb particles were accumulated in the pores of the magnetite flakes and electrically contacted to the steam generator materials. The micro-galvanic corrosion behavior of steam generator materials (steam generator tube materials: Alloy 600 and Alloy 690, steam generator tube sheet materials: SA508 Gr.3) contacted to the corrosion products (magnetite, Cu, and Pb) was investigated in an alkaline solution. The steam generator materials considered in this study were all the anodic elements of the galvanic pair because their corrosion potentials were lower than those of the corrosion products. The corrosion rate of the steam generator materials was increased by the galvanic coupling with the each corrosion products, and was more accelerated with increasing the area ratio of the corrosion products to the steam generator materials. Among the corrosion products, Cu has the largest galvanic effect on steam generator materials in the pores when area ratio of cathode to anode is 10.

Evaluation of single heated channel and subchannel modeling of a nuclear once through steam generator (OTSG)

Kerntechnik ◽  
2020 ◽  
Vol 85 (1) ◽  
pp. 54-67
Author(s):  
A. Hamedani ◽  
O. Noori-Kalkhoran ◽  
R. Ahangari ◽  
M. Gei
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Axial Direction ◽  
Pressurized Water Reactors ◽  
Steam Generators ◽  
Pressurized Water ◽  
Heated Channel ◽  
Water Reactors ◽  
Secondary Side

Abstract Steam generators are one of the most important components of pressurized-water reactors. This component plays the role of heat transfer and pressure boundary between primary and secondary side fluids. The Once Through Steam Generator (OTSG) is an essential component of the integrated nuclear power system. In this paper, steady-state analysis of primary and secondary fluids in the Integral Economizer Once Through Steam Generator (IEOTSG) have been presented by Single Heated Channel (SHC) and subchannel modelling. Models have been programmed by MATLAB and FORTRAN. First, SHC model has been used for this purpose (changes are considered only in the axial direction in this model). Second, the subchannel approach that considers changes in the axial and also radial directions has been applied. Results have been compared with Babcock and Wilcox (B&W) 19- tube once through steam generator experimental data. Thermal- hydraulic profiles have been presented for steam generator using both of models. Accuracy and simplicity of SHC model and importance of localization of thermal-hydraulic profiles in subchannel approach have been proved.

scholarly journals Simulation of the Thermal Hydraulic Processes in the Horizontal Steam Generator with the Use of the Different Interfacial Friction Correlations

2011 ◽  
Vol 2011 ◽  
pp. 1-9
Author(s):  
Vladimir Melikhov ◽  
Oleg Melikhov ◽  
Yury Parfenov ◽  
Alexey Nerovnov
Keyword(s):  
Steam Generator ◽  
Three Dimensional ◽  
Test Facility ◽  
Interfacial Friction ◽  
Water Mixture ◽  
Pressurized Water ◽  
Design And Optimization ◽  
Water Flows ◽  
Horizontal Steam Generator ◽  
Water Reactors

The horizontal steam generator (SG) is one of specific features of Russian-type pressurized water reactors (VVERs). The main advantages of horizontal steam generator are connected with low steam loads on evaporation surface, simple separation scheme and high circulation ratio. The complex three-dimensional steam-water flows in the steam generator vessel influence significantly the processes of the steam separation, distribution, and deposition of the soluble and nonsoluble impurities and determine the efficiency and reliability of the steam generator operation. The 3D code for simulation of the three-dimensional steam-water flows in the steam generator could be effective tool for design and optimization of the horizontal steam generator. The results of the code calculations are determined mainly by the set of the correlations describing interaction of the steam-water mixture with the inner constructions of the SG and interfacial friction. The results obtained by 3D code STEG with the usage of the different interfacial friction correlations are presented and discussed in the paper. These results are compared with the experimental ones obtained at the experimental test facility PGV-1500 constructed for investigation of the processes in the horizontal steam generator.

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