scholarly journals ASSESSMENT OF POSSIBILITY OF PRIMARY WATER STRESS CORROSION CRACKING OCCURRENCE BASED ON RESIDUAL STRESS ANALYSIS IN PRESSURIZER SAFETY NOZZLE OF NUCLEAR POWER PLANT

2012 ◽  
Vol 44 (3) ◽  
pp. 343-354 ◽  
Author(s):  
Kyoung-Soo Lee ◽  
W. Kim ◽  
Jeong-Geun Lee
Keyword(s):  
Residual Stress ◽  
Water Stress ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Stress Analysis ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Nuclear Power ◽  
Primary Water ◽  
Residual Stress Analysis

Application of Surface Stress Improvement Technologies to Nuclear Power Plant Components

2005 ◽  
Author(s):  
Ronald J. Payne ◽  
Stephen Levesque
Keyword(s):  
Water Stress ◽  
Stress State ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Surface Stress ◽  
Nuclear Power ◽  
Alloy 600 ◽  
Contributing Factors ◽  
Primary Water ◽  
Plant Components

The susceptibility of Alloy 600 to Primary Water Stress Corrosion Cracking (PWSCC) has proven detrimental to several nuclear power plant components. Repair, modification or replacement of the components to mitigate the effects of PWSCC on Alloy 600 has been deemed necessary. In some cases, repair or replacement of plant components can be exorbitantly expensive; therefore, modification of the components is necessary to keep the plant operable. A form of modification is surface stress improvement, which alters the stress state of the material. Changing the stress state of the material eliminates one of the contributing factors required for the propagation of PWSCC. This paper discusses the application of surface stress improvement technologies to commercial nuclear power plant components and provides insight to where these technologies can be employed in the future.

scholarly journals Factors Involved in Stress Corrosion Cracking of Tubes from a Nuclear Power Plant Feedwater Heater

2019 ◽  
Vol 70 (11) ◽  
pp. 3926-3930
Author(s):  
Manuela Fulger ◽  
Dumitra Lucan ◽  
Maria Mihalache ◽  
Lucian Velciu
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Nuclear Power ◽  
High Water ◽  
Corrosion Cracking ◽  
304 Stainless Steel ◽  
Final Conclusion ◽  
X Ray

This study has been carried out to identify the operating factors involved in the failure of two tubes made of 304 stainless steel removed from a high pressure feedwater heater working in a nuclear power plant. The samples cut from tubes have been analyzed by different methods: visual examination, optical (metallographic) microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Following analyses, on the surface of tubes was highlighted the presence of many pits in which cracks have started. Inside the pits, impurities of the type S, Cl, K, Ca were detected too. The branched cracks most likely have occurred as a result of precipitation of small amounts of chlorides deposited and concentrated on the surface of the tubes over a long period of operation. The stresses that favored this type of corrosion cracking were both residual stresses and stresses occurring at the torsion and bending of the tubes, while the high water temperature from feed heater was also a favorable factor for corrosion. The final conclusion was that the tubes failed by a chloride induced stress corrosion cracking mechanism.

scholarly journals Factors Involved in Stress Corrosion Cracking of Tubes from a Nuclear Power Plant Feedwater Heater

2019 ◽  
Vol 70 (11) ◽  
pp. 3926-3930
Author(s):  
Manuela Fulger ◽  
Dumitra Lucan ◽  
Maria Mihalache ◽  
Lucian Velciu
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Nuclear Power ◽  
High Water ◽  
Corrosion Cracking ◽  
304 Stainless Steel ◽  
Final Conclusion ◽  
X Ray

This study has been carried out to identify the operating factors involved in the failure of two tubes made of 304 stainless steel removed from a high pressure feedwater heater working in a nuclear power plant. The samples cut from tubes have been analyzed by different methods: visual examination, optical (metallographic) microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Following analyses, on the surface of tubes was highlighted the presence of many pits in which cracks have started. Inside the pits, impurities of the type S, Cl, K, Ca were detected too. The branched cracks most likely have occurred as a result of precipitation of small amounts of chlorides deposited and concentrated on the surface of the tubes over a long period of operation. The stresses that favored this type of corrosion cracking were both residual stresses and stresses occurring at the torsion and bending of the tubes, while the high water temperature from feed heater was also a favorable factor for corrosion. The final conclusion was that the tubes failed by a chloride induced stress corrosion cracking mechanism.

Assessment of J-Integrals for Surface Cracks in a Weld Metal

2012 ◽  
Author(s):  
Young-Chul Park ◽  
Jae-Uk Jeong ◽  
Jae-Boong Choi ◽  
Yoon-Suk Chang ◽  
Sung-Woo Kim ◽  
...  
Keyword(s):  
Residual Stress ◽  
Water Stress ◽  
Stress Corrosion ◽  
Nuclear Power ◽  
Power Plants ◽  
Driving Mechanism ◽  
Surface Cracks ◽  
Stress Distributions ◽  
Control Rod ◽  
Primary Water

Lots of defects due to primary water stress corrosion cracking have been observed at diverse penetration locations of major components in nuclear power plants. To resolve this issue, during the past couple of decades, numerous analytical and experimental researches have been carried out to determine residual stress distributions in dissimilar metal welds that are plausible to crack initiation caused by the primary water stress corrosion. The present research deals with prediction of J-integrals for axial inner surface cracks in a mock-up that is to resemble upper head of reactor pressure vessel with penetrations of control rod driving mechanism. At first, representative residual stress distributions at J-groove welded region of the mock-up were calculated through finite element analyses of un-cracked models according to practical welding procedure. Then, J-integrals were calculated by mapping the residual stress distributions to the cracked models with different shapes. Based on these parametric analyses, effects of varying crack geometries were investigated of which are fully discussed in the manuscript.

Sign in / Sign up

Export Citation Format

Share Document