AREVA’s Fatigue Concept – An Integrated and Multidisciplinary Approach to the Fatigue Assessment of NPP Components
Jürgen Rudolph, Steffen Bergholz, Benedikt Heinz,
and Nikolaus Wirtz
Department PEEA-G, AREVA NP GmbH, Henri-Dunant-Strasse 50, 91058 Erlangen, Germany
Preventing fatigue damage is crucial in changing boundary conditions such as code modification, lifetime extension, new plants with operating periods of 60 years. The AREVA fatigue concept (AFC) provides for a multiple-step multidisciplinary process – process engineering, fatigue monitoring, fatigue analysis, etc. – against fatigue before and during the entire nuclear power plant (NPP) operation. Fatigue analysis is based on real operational loads measured continuously on site in plants via fatigue monitoring, enabling qualified fatigue usage factors to be determined. Potential fatigue failure sites are reliably identified, reducing expensive inspection costs. Direct processing of measured temperatures is immediately used for a first automated fast fatigue estimation. In the periodic safety inspection (PSI) framework, detailed fatigue check conforming to code rules and based on real loads is recommended. The additional check against progressive plastic deformation (ratcheting) is unique. In the elastic plastic approach, much care must be taken in applying appropriate material law and extrapolation emanating from a low number of analyzed cycles.
and Nikolaus Wirtz, “AREVA’s Fatigue Concept – An Integrated and Multidisciplinary Approach to the Fatigue Assessment of NPP Components,” J. Disaster Res., Vol.6, No.1, pp. 155-164, 2011.
-  ASME, “Boiler & Pressure Vessel Code,” Section III, Division 1 – Subsection NB: Class 1 Components, Rules for Construction of Nuclear Power Plant Components, 2007.
-  “Components of the Reactor Coolant Pressure Boundary of Light Water Reactors, Part 2: Design and Analysis,” KTA, 3201.2 (06/96), 1996.
-  “RCC-M Edition 2000,” Section I, Subsection B: Class 1 components, Design and Construction Rules for Mechanical Components of PWR Nuclear Islands.
-  “Pressure and Activity Retaining Components of Systems Outside the Primary Circuit, Part 2: Design and Analysis,” KTA, 3211.2 (06/92), 1992.
-  W. Kleinöder and C. Pöckl, “Developing and implementation of a fatigue monitoring system for the new European pressurized water reactor EPR,” Proceedings of the International Conference “Nuclear Energy for New Europe 2007,” Portoroz, Slovenia, September 10-13, 2007.
-  M. Matsuishi and T. Endo, “Fatigue of metals subjected to varying stresses,” Proceedings of the Kyushu branch of the Japanese Society of Mechanical Engineers, March 1968.
-  M. Miksch, G. Schön, and B. Thomas, “FAMOS – a tool for transient recording and fatigue monitoring,” Proceedings of PVP-1988, 1988 ASME Pressure Vessels and Piping Division Conference, June 19-23, 1988, Pittsburgh, Pennsylvania, USA.
-  S. A. Adams, “An Alternate Simplified Elastic-Plastic Analysis Method,” ASME Code correspondence, Technical Support Document, January 19, 2005.
-  M. Hoffmann, T. Seeger, and H. Führing, “Proposal for an improvement of the Ke-procedure of the ASME-Code,” Technical University of Darmstadt, FF-2/1985.
-  B. O’Donnell, “Proposed Section III Fatigue Design Curves for Air Environments,” ASME Code correspondence, November 7, 2007.
-  NUREG/CR-6909 ANL-06/08, 2007, “Effect of LWR Coolant Environments on the Fatigue Life of Reactor Materials,” Final Report, Argonne National Laboratory, February 2007.
-  S. Bari and T. Hassan, “Anatomy of coupled constitutive models for ratcheting simulation,” International Journal of Plasticity, Vol.16, pp. 381-409, 2000.
-  S. M. Rahman and T. Hassan, “Advanced Cyclic Plasticity Models in Simulating Ratcheting Responses of Straight and Elbow Piping Components, and Notched Plates,” Proceedings of PVP-2005, Denver, Colorado, USA, 2005.
-  “Multi Purpose Finite Elemente Code,” ANSYS Rev. 11. 2007.
-  A. Willuweit, “Implementierung der Materialmodelle von Chaboche und Ohno & Wang in ANSYS zur Simulation von mechanisch- und thermomechanisch induzierter fortschreitender plastischer Deformation,” Proceedings of ANSYS Conference & 27th CADFEM Users’ Meeting, November 18-20, 2009, Leipzig, Germany.
-  M. Vormwald, “The Consequences of Short Crack Closure on Fatigue Crack Growth Under Variable Amplitude Loading,” Fatigue Fract. Engng. Mater. Struct., Vol.14, No.2/3, pp. 205-225, 1991.
-  M. Vormwald, P. Heuler, and C. Krae, “Spectrum Fatigue Life Assessment of Notched Specimens Using a Fracture Mechanics Based Approach,” ASTM STP 1231, pp. 221-240, 1994.
-  G. Savaidis and T. Seeger, “Consideration of Multiaxiality in Fatigue Life Prediction Using the Closure Concept,” Fatigue Fract. Engng. Mater. Struct., Vol.20, No.7, pp. 985-1004, 1997.
-  G. Savaidis, A. Savaidis, and T. Seeger, “Engineering Components under Multiaxial Loading. Fatigue Analysis and Lifetime Evaluation,” MP Materialprüfung, Vol.43, No.3, pp. 76-86, 2001.
-  K. Bauerbach, M. Vormwald, and J. Rudolph, “Fatigue assessment of nuclear power plant components subjected to thermal cyclic loading,” PVP-2009-77450, Proceedings of PVP-2009, 2009 ASME Pressure Vessels and Piping Division Conference, Prague, Czech Republic, July 26-30, 2009.
-  J. Rudolph, K. Bauerbach, and M. Vormwald, “Numerical Investigations of Phenomena Caused by the Closure and Growth Behavior of Short Cracks Under Thermal Cyclic Loading,” Proceedings of PVP-2010, 2010 ASME Pressure Vessels and Piping Division Conference, July 18-22, 2010, Bellevue, Washington, USA.
-  S. Palm, H. Gertkemper, P. Knoch, and K. Maile, “A study of the early stages of fatigue damage in power plant steels,” Proceedings of the 31st MPA-Seminar in conjunction with the symposium “Materials & Components Behaviour in Energy & Plant Technology,” Stuttgart, Germany, October 13-14, 2005.
-  J. Schreiber and M. Kröning, “Evaluation of fatigue damage of steel for nuclear power stations by the fractal features of deformation structures and their noise behaviour,” Proceedings of the 31st MPASeminar in conjunction with the symposium “Materials & Components Behaviour in Energy & Plant Technology,” Stuttgart, Germany, October 13-14, 2005 (in German).