PSI - Issue 60

10

Rahul Mittal/ Structural Integrity Procedia 00 (2019) 000 – 000

Rahul Mittal et al. / Procedia Structural Integrity 60 (2024) 604–613

613

7.2 Fatigue Cyclic loading of Thermal stresses poses a risk to the structural integrity FWN and if the combined stresses from primary loading are high enough to initiate propagation of pre-existing defects. Hence Fatigue evaluation is performed in accordance with the ASME Section III, sub-section NB has been performed. The most critical locations are identified for susceptible failure to fatigue and detailed evaluation in line with the ASME Section III NB3222.4 is performed for FWN & Thermal sleeve. As observed in tables below for the damage factors reported, the cumulative fatigue damage factor for sleeve and nozzle is much less than 1 and hence safe for fatigue of various transients. 8. Conclusion: Structural integrity of FWN and Thermal sleeve of 700 MWe Steam generators is performed through Thermo mechanical analysis using FEM. The FE results of analysis indicated that FWN with thermal sleeve are having higher stresses at the crotch location. However, they are found to be safe under the stress categorization with reference to the code limits of ASME. Assessment was performed for the primary stresses stress limits to prevent plastic deformation on burst pressures. Also, the primary + secondary stresses limits checked for limits to prevent incremental collapse. Peak stress limits checked by fatigue evaluation for cyclic loadings. References [1] RULES FOR CONSTRUCTION OF NUCLEAR FACILITY COMPONENTS Division 1 - Subsection NB Class 1 Component. AN INTERNATIONAL CODE 2015 ASME Boiler & Pressure Vessel Code 2015 Edition July 1, 2015. [2] Jianjun Wang, Zengfang Ge, Zhongning Sun, Changqi Yan. The Surge Line Stress Analysis Model Setup With the Consideration of Thermal Stratification. 2014 22nd International Conference on Nuclear Engineering. [3] T. L. Meikle, V, E. D. Johnson, M. A. Gray, N. L. Glunt, J. D. Burr. Simulation and Evaluation of Thermal Stratification in a Sloped Surge Nozzle Correlated With Plant Measurements. ASME 2011 Pressure Vessels and Piping Conference July 17 – 21, 2011 Baltimore, Maryland, USA. [4] Dong Gu Kang, Myung Jo Jhung, Soon Heung Chang. Fluid – structure interaction analysis for pressurizer surge line subjected to thermal stratification. Nuclear Engineering and Design Volume 241, Issue 1, January 2011, Pages 257-269 . [5] Young J. Oh, Kwang J. Jeong, Byung G. Park, Il S. Hwang. Local Failure Modes of a Nuclear Reactor Pressure Vessel Nozzle Under Severe Accident Conditions. ASME 2002 Pressure Vessels and Piping Conference; August 5 – 9, 2002; Vancouver, BC, Canada . [6] Shuai Wang, Bin Wang, Guiyi Wu, He Xue, Yuman Sun, Jiajun Zhu. Effects of angles and shapes of a corner crack on the driving force at a set-in nozzle-cylinder in a PWR pressure vessel. Annals of Nuclear Energy; Volume 192, November 2023, 109991 . [7] Wenchun Jiang, Yun Luo, B.Y. Wang, S.T. Tu, J.M. Gong. Residual stress reduction in the penetration nozzle weld joint by overlay welding. Materials & Design Volume 60, August 2014, Pages 443-450 . [8] Timothy Gilman, Archana Chinthapalli, Michael Hoehn, II. Stress-Based Environmental Fatigue Monitoring of PWR Charging Nozzle. ASME 2013 Pressure Vessels and Piping Conference July 14 – 18, 2013 Paris, France . [9] T. L. Meikle, V, E. D. Johnson, M. A. Gray, N. L. Glunt, J. D. Burr. Simulation and Evaluation of Thermal Stratification in a Sloped Surge Nozzle Correlated With Plant Measurements. ASME 2011 Pressure Vessels and Piping Conference, July 17 – 21, 2011, Baltimore, Maryland, USA . [10] Shen Rui, Cao Ming, He Yinbiao, Tao Hongxin. Research on the Fracture Mechanics Analysis Method for Reactor Pressure Vessel Nozzle Corner Flaw. 2017 25th International Conference on Nuclear Engineering; July 2 – 6, 2017; Shanghai, China.