Abstract
The first part of this review considers the prerequisites and scales of damage inflicted to the equipment and pipelines of power plant units as a consequence of flow-accelerated corrosion, and examples of accidents involving lethal outcomes that occurred at nuclear power plants as a result of pipeline ruptures caused by flow-accelerated corrosion are given. It is shown that the scope of items susceptible to flow-accelerated corrosion includes components of condensate–feedwater and wet steam path equipment and pipelines made of carbon and low-alloy steels. The main negative consequences caused by flow-accelerated corrosion are local metal thinning spots that can lead to abrupt failures and depressurization of the process circuit and contamination of working fluid with iron containing products of flow-accelerated corrosion. Sedimentation of these products in a steam generator is one of factors causing damage to and failure of its heat transfer tubes. It is proposed to draw a distinction between general and local flow-accelerated corrosion. General flow-accelerated corrosion causes ingress of iron-containing compounds into the working fluid and is characterized by a moderate metal thinning rate that does not lead to destructions or occurrence of wormholes involving loss of process circuit leak tightness. The effects of local flow-accelerated corrosion manifest themselves in small parts of intricately shaped channels and are characterized by a significant metal thinning rate with possible occurrence of wormholes or abrupt destruction of the pipeline and power-generating equipment components. Typical cases of and statistical data on damages inflicted to nuclear power plant components due to flow-accelerated corrosion are presented. The physicochemical fundamentals and regularities relating to flow-accelerated corrosion of metal occurring in one- and two-phase flows are considered. It is pointed out that the hydrodynamic factor plays the determining role in the occurrence of zones and rate of local thinning caused by flow-accelerated corrosion. The key hydrodynamic characteristics influencing the local flow-accelerated corrosion rate are determined. Fundamental differences between the mechanisms governing flow-accelerated corrosion in two-phase medium and single-phase water flow are shown. These differences stem from the specific features of hydrodynamics pertinent to the motion of liquid film and interphase redistribution of admixtures and gases that gives rise to a change in the pH value of liquid. The results from experiments aimed at studying the effect of temperature on the flow-accelerated corrosion rate of different metals in a two-phase wet steam flow and the effect of steam wetness degree on the liquid film flow mode are presented.
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References
O. A. Povarov, G. V. Tomarov, A. F. Gontarenko, and E. V. Velichko, Erosion-Corrosion Wear of the Metal of Turbine Unit Elements at Thermal and Nuclear Power Plants (TsNIITEItyazhmash, Moscow, 1991) [in Russian].
B. Chexal, J. Horowitz, R. Jones, B. Dooley, C. Wood, M. Bouchacourt, F. Remy, F. Nordmann, and P. Saint-Paul, Flow-Accelerated Corrosion in Power Plants, Electric Power Research Institute Report TR-106611 (1996).
G. Bignold, K. Garbert, R. Garnsey, and L. Woolsey, “Erosion-corrosion in nuclear steam generators,” in Proc. 2nd Int. Conf. on Water Chemistry of Nuclear Reactor Systems, Bournemouth, UK, Oct. 14–17, 1980 (British Nuclear Energy Society, London, 1981), pp. 5–18.
B. Dooley, “Update on FAC in fossil and combined cycle, HRSG Plants,” in Proc. Int. Conf. on Flow Accelerated Corrosion (FAC 2016), Lille, France, May 24–27, 2016.
O. A. Povarov, G. V. Tomarov, S. Yu. Kutyrev, and E. V. Velichko, The Problems of Scaling and Wear of the Elements of Geothermal Power Generation Installations (TsNIITEItyazhmash, Moscow, 1991) [in Russian].
O. A. Povarov, G. V. Tomarov, and V. N. Semenov, “Physical and chemical processes of geothermal fluid impact on metal of geothermal power plant equipment,” in Proc. World Geothermal Congress 2000, Kyushu–Tohoku, Japan, May 28–June 10, 2000 (International Geothermal Association, Auckland, New Zealand, 2000).
P. Combrade, P. Ford, and P. Scott, Key Emerging Issues and Recent Progress Relating to Structural Materials Degradation, LCC8 Annual Report (2012).
Flow Accelerated Corrosion (FAC) of Carbon Steel and Low Alloy Steel Piping in Commercial Nuclear Power Plants, Topical Report, NEA/CSNI/R (2014).
P. Berg and P. Saint-Paul, in Proc. 2nd Int. Conf. on Water Chemistry of Nuclear Reactor Systems, Bournemouth, UK, Oct. 14–17, 1980 (British Nuclear Energy Society, London, 1981).
L. E. Sanchez-Caldera, P. Griffith, and E. Rabinowicz, “The mechanism of corrosion-erosion in steam extraction lines of power station,” Trans. ASME. J. Eng. Gas Turbines Power 110, 180–184 (1988).
H. G. Heitmann and W. Kastner, “Erosion-corrosion in water/steam cycles — Causes and corrective measures,” VGB Kraftwerkstech. 62, 211–219 (1982).
G. V. Tomarov and A. A. Shipkov, “Principles of development and specific features relating to practical application of software for solving problems connected with erosion-corrosion of metal in power engineering,” Therm. Eng. 58, 135–142 (2011).
W. Kastner, K. Riedle, and H. Tratz, “Experimentelle Untersachungen zum Materialabtrag durch Erosionskorrosion,” VGB Kraftwerkstech. 64, 452–465 (1984).
B. Poulson, “Predicting and preventing flow accelerated corrosion in nuclear power plant,” Int. J. Nucl. Energy 23, 423295 (2014).
Y. Utanohara, Y. Nagaya, A. Nakamura, and M. Murase, “Influence of local flow field on flow accelerated corrosion downstream from an orifice,” J. Power Energy Syst. 6, 18–33 (2012).
G. V. Tomarov, A. A. Shipkov, and N. S. Koreshkova, “Calculated and experimental substantiation of operating conditions under which adequate erosion resistance of valves used in power units at nuclear power stations is ensured,” Therm. Eng. 57, 382–390 (2010).
G. V. Tomarov, A. A. Shipkov, T. N. Golubeva, and P. N. Greblov, “An investigation of the effect of hydrodynamics of flow on erosion-corrosion resistance of components of a feedwater control assembly used in power units of nuclear power plants equipped with RBMK-1000 reactors,” Therm. Eng. 60, 591–597 (2013). doi 10.1134/S0040601513080090
G. V. Tomarov, “Erosion-corrosion of structural materials of saturated-steam turbines,” Teploenergetika, No. 7, 33–38 (1987).
O. A. Povarov, B. Stanisa, and G. V. Tomarov, “Erosionskorrosions-Abtragung von Metall im Strömungsteil einer Nassdampfturbine,” Brennstoff Warme-Kraft. 38 (12), 534–538 (1986).
E. Kunze von and W. Allgaier, “Erosionkorrosion in Nabdampf,” VGB Kraftwerkstech. 65, 64–70 (1985).
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Original Russian Text © G.V. Tomarov, A.A. Shipkov, 2018, published in Teploenergetika.
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Tomarov, G.V., Shipkov, A.A. Flow-Accelerated Corrosion Wear of Power-Generating Equipment: Investigations, Prediction, and Prevention: 1. Flow-Accelerated Corrosion Processes and Regularities. Therm. Eng. 65, 493–503 (2018). https://doi.org/10.1134/S0040601518080062
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DOI: https://doi.org/10.1134/S0040601518080062