Westinghouse Presentation Template Class 3
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Review of reactor containment building corrosion events and prediction corrosion rates Andrew Ruminski Westinghouse Electric Company Materials Center of Excellence Churchill
1
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Operating Experience • Non-uniform, through-wall, corrosion at interface between containment liner steel & concrete • Several incidents worldwide1-3 – Brunswick Unit 2 - 1999 – Anna Unit 2 - 1999 – D.C. Cook Unit 2 - 1999 – Beaver Valley Unit 1 - 2009 and 2013 National Laboratory Report SAND2010-8718, “Nuclear Containment – Ringhals Unit 2 - 2006 1) Sandia Steel Liner Corrosion Workshop: Final Summary and Recommendations Report,” July 2011. – Various French plants 2) V. Shah and C. Hookman, “Long-term aging of light water reactor concrete containments,” Nuclear Engineering & Design, Vol. 185 (1998), pp. 51-81 3) P. Effsing, “Containment Leakages – Ringhals Unit 2,” PWROG-MSC Hollywood, Florida, April 2015. 2
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Through-Wall Corrosion Incidents • Incidents associated with organic foreign material – Embedded gloves, brushes, and / or lumber – Source of chlorides, sulfates & organic acids • Ringhals Unit 2 attributed to pitting corrosion & MIC Average Penetration Rates (mmpy) North Anna 2 0.41 D. C. Cook 2 0.38 Beaver Valley Unit 1 0.25 Passivity perturbed 3
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Conditions of Through-wall Corrosion • • • •
Measurable sulfates, fluorides, & chlorides at interface Black corrosion deposits (magnetite) at concrete interface Formation of magnetite due to low oxygen & chlorides3-6 Sulfur bearing specimens & yellow deposits on plant side – Possible evidence of MIC
• pH from swipe ~ 6 – Non-passivating – Conducive to SRB-MIC 7
3) R. Javaherdashti, Microbiologically Influenced Corrosion: An Engineering Insight, Springer-Verlag, London (2008). 4) F. R. Pérez et al.,“Effect of Chloride Concentration, Immersion Time and Steel Composition on the Spinel Phase Formation”, Materials Chemistry and Physics, 117, 214-223, (2009). 5) C. T. Lee et al., “An In Situ Raman-Electrochemical Investigation of Carbon Steel Corrosion in Na2CO3 / NaHCO3, Na2SO4 and NaCl Solutions”, Journal of the Electrochemical Society, 153 (2), B33-B41, (2006). 6) C. A. Barrero et al., “On Magnetite Formation as a Corrosion Product of Steel”, Proceedings of the International Conference on the Applications of the Mössbauer Effect, September 2-7 2001, Oxford. 7) R. Javaherdashti, Microbiologically Influenced Corrosion: An Engineering Insight, Springer-Verlag, London (2008). 4
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Liner / Concrete Interface Swipe: pH ~6 SO4-2 0.8 µg / cm2 F- 0.2 µg / cm2 Cl- 0.1 µg / cm2 Black Oxide
EDS Data from Thick Black Oxide (Magnetite) C O Si Ca Mn Spectrum (w %) (w %) (w %) (w %) (w %) 2.6 30.6 0.1 0.1 1.2 1 5
Fe (w %) 65.4
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Plant Side, Leaking from Hole
Yellow Deposit
Sulfur bearing Possible MIC byproduct
Spectra 1 2 3 4 5 6
C (w %) 13.3 2.5 12.4 14.5 18.4 77.2
O (w %) 37.0 5.3 38.1 42.7 29.6 22.8
EDS Data from Yellow Deposit Cr Si S Ti Mn (w %) (w %) (w %) (w %) (w %) 0.2 0.2 1.6 0.1 0.2 0.2 1.3 0.8 0.5 0.1 0.4 1.1 1.0 1.6 0.2 0.6 0.3 0.9 0.6 0.2 6
Fe (w %) 46.7 88.3 48.2 37.0 48.9 -
Cu (w %) 0.9 -
Zn (w %) 0.7 1.2 0.7 0.4 1.1 -
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Published Data • General corrosion rates of steels near ambient 6-9 – Less severe than liner plate rates observed in NPP
• Atmospheric conditions ~ 0.025 mm per year (mpy) • Passivating high pH environment (~ 12.5) in concrete 1-2 – Corrosion rates in concrete 5 to 10 lower 6) ASM Handbook of Corrosion Data, edited by B. D. Craig, First Edition, p. 160. 7) M. Raphael and R. Shalon, “Influence of Climate on Corrosion of Reinforcement,” Proceedings International RILEM Symposium, Vol. 1, 1971, pp. 177-196. 8) E. Escalante and S. Ito, “Measuring the Rate of Corrosion of Steel in Concrete,” Corrosion Rates of Steel in Concrete, ASTM STP 1065, N. Berke et al. editors, pp. 86-102. 9) C. Locke and A. Siman, “Electrochemistry of Reinforcing Steel in Salt Contaminated Concrete,” Corrosion of Reinforcing Steel in Concrete, ASTM STP 713, D. Tonini and J. Gaidis editors, pp. 3-16.
7
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Summary of Published Ambient Corrosion Rates Corrosion Rates for Structural Carbon Steel Exposure Conditions
mmpy
Ref
Atmospheric, 1st Several Years Atmospheric, Past Several Years Encased in concrete, no salt Encased in concrete, exposed salt Encased in concrete,1.0% NaCl
0.025 0.013 0.003 0.013 0.14
6 6 7 8 9
Observed NPP Liner Corrosion ~3x greater 8
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Thermal Effects • • • •
Corrosion data assumed to be 25oC (77oF) Operating temperature of NPP liner 100 years with active corrosion (non contamination)
• Penetration incidents associated with contamination – Chlorides, organic acids, MIC – Up to 0.4 mmpy – >25 year to penetrate liners
15
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Review of reactor containment building corrosion events and prediction corrosion rates Andrew Ruminski Westinghouse Electric Company Materials Center of Excellence Churchill
1
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Operating Experience • Non-uniform, through-wall, corrosion at interface between containment liner steel & concrete • Several incidents worldwide1-3 – Brunswick Unit 2 - 1999 – Anna Unit 2 - 1999 – D.C. Cook Unit 2 - 1999 – Beaver Valley Unit 1 - 2009 and 2013 National Laboratory Report SAND2010-8718, “Nuclear Containment – Ringhals Unit 2 - 2006 1) Sandia Steel Liner Corrosion Workshop: Final Summary and Recommendations Report,” July 2011. – Various French plants 2) V. Shah and C. Hookman, “Long-term aging of light water reactor concrete containments,” Nuclear Engineering & Design, Vol. 185 (1998), pp. 51-81 3) P. Effsing, “Containment Leakages – Ringhals Unit 2,” PWROG-MSC Hollywood, Florida, April 2015. 2
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Through-Wall Corrosion Incidents • Incidents associated with organic foreign material – Embedded gloves, brushes, and / or lumber – Source of chlorides, sulfates & organic acids • Ringhals Unit 2 attributed to pitting corrosion & MIC Average Penetration Rates (mmpy) North Anna 2 0.41 D. C. Cook 2 0.38 Beaver Valley Unit 1 0.25 Passivity perturbed 3
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Conditions of Through-wall Corrosion • • • •
Measurable sulfates, fluorides, & chlorides at interface Black corrosion deposits (magnetite) at concrete interface Formation of magnetite due to low oxygen & chlorides3-6 Sulfur bearing specimens & yellow deposits on plant side – Possible evidence of MIC
• pH from swipe ~ 6 – Non-passivating – Conducive to SRB-MIC 7
3) R. Javaherdashti, Microbiologically Influenced Corrosion: An Engineering Insight, Springer-Verlag, London (2008). 4) F. R. Pérez et al.,“Effect of Chloride Concentration, Immersion Time and Steel Composition on the Spinel Phase Formation”, Materials Chemistry and Physics, 117, 214-223, (2009). 5) C. T. Lee et al., “An In Situ Raman-Electrochemical Investigation of Carbon Steel Corrosion in Na2CO3 / NaHCO3, Na2SO4 and NaCl Solutions”, Journal of the Electrochemical Society, 153 (2), B33-B41, (2006). 6) C. A. Barrero et al., “On Magnetite Formation as a Corrosion Product of Steel”, Proceedings of the International Conference on the Applications of the Mössbauer Effect, September 2-7 2001, Oxford. 7) R. Javaherdashti, Microbiologically Influenced Corrosion: An Engineering Insight, Springer-Verlag, London (2008). 4
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Liner / Concrete Interface Swipe: pH ~6 SO4-2 0.8 µg / cm2 F- 0.2 µg / cm2 Cl- 0.1 µg / cm2 Black Oxide
EDS Data from Thick Black Oxide (Magnetite) C O Si Ca Mn Spectrum (w %) (w %) (w %) (w %) (w %) 2.6 30.6 0.1 0.1 1.2 1 5
Fe (w %) 65.4
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Plant Side, Leaking from Hole
Yellow Deposit
Sulfur bearing Possible MIC byproduct
Spectra 1 2 3 4 5 6
C (w %) 13.3 2.5 12.4 14.5 18.4 77.2
O (w %) 37.0 5.3 38.1 42.7 29.6 22.8
EDS Data from Yellow Deposit Cr Si S Ti Mn (w %) (w %) (w %) (w %) (w %) 0.2 0.2 1.6 0.1 0.2 0.2 1.3 0.8 0.5 0.1 0.4 1.1 1.0 1.6 0.2 0.6 0.3 0.9 0.6 0.2 6
Fe (w %) 46.7 88.3 48.2 37.0 48.9 -
Cu (w %) 0.9 -
Zn (w %) 0.7 1.2 0.7 0.4 1.1 -
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Published Data • General corrosion rates of steels near ambient 6-9 – Less severe than liner plate rates observed in NPP
• Atmospheric conditions ~ 0.025 mm per year (mpy) • Passivating high pH environment (~ 12.5) in concrete 1-2 – Corrosion rates in concrete 5 to 10 lower 6) ASM Handbook of Corrosion Data, edited by B. D. Craig, First Edition, p. 160. 7) M. Raphael and R. Shalon, “Influence of Climate on Corrosion of Reinforcement,” Proceedings International RILEM Symposium, Vol. 1, 1971, pp. 177-196. 8) E. Escalante and S. Ito, “Measuring the Rate of Corrosion of Steel in Concrete,” Corrosion Rates of Steel in Concrete, ASTM STP 1065, N. Berke et al. editors, pp. 86-102. 9) C. Locke and A. Siman, “Electrochemistry of Reinforcing Steel in Salt Contaminated Concrete,” Corrosion of Reinforcing Steel in Concrete, ASTM STP 713, D. Tonini and J. Gaidis editors, pp. 3-16.
7
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Summary of Published Ambient Corrosion Rates Corrosion Rates for Structural Carbon Steel Exposure Conditions
mmpy
Ref
Atmospheric, 1st Several Years Atmospheric, Past Several Years Encased in concrete, no salt Encased in concrete, exposed salt Encased in concrete,1.0% NaCl
0.025 0.013 0.003 0.013 0.14
6 6 7 8 9
Observed NPP Liner Corrosion ~3x greater 8
Westinghouse Non-Proprietary Class 3
© 2016 Westinghouse Electric Company LLC. All Rights Reserved.
Thermal Effects • • • •
Corrosion data assumed to be 25oC (77oF) Operating temperature of NPP liner 100 years with active corrosion (non contamination)
• Penetration incidents associated with contamination – Chlorides, organic acids, MIC – Up to 0.4 mmpy – >25 year to penetrate liners
15
