Journal of Mechanical Science and Technology

The Korean Society of Mechanical Engineers (대한기계학회)
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Structural Integrity Evaluation for Interference-fit Flywheels in Reactor Coolant Pumps of Nuclear Power Plants

  • Park June-soo (Mechanical System Engineering Dept., Korea Power Engineering Company, Inc.) ;
  • Song Ha-cheol (Mechanical System Engineering Dept., Korea Power Engineering Company, Inc.) ;
  • Yoon Ki-seok (Mechanical System Engineering Dept., Korea Power Engineering Company, Inc.) ;
  • Choi Taek-sang (Mechanical System Engineering Dept., Korea Power Engineering Company, Inc.) ;
  • Park Jai-hak (Safety Engineering Dept., College of Engineering, Chungbuk National University)
  • Published : 2005.11.01
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Abstract

This study is concerned with structural integrity evaluations for the interference-fit flywheels in reactor coolant pumps (RCPs) of nuclear power plants. Stresses in the flywheel due to the shrinkage loads and centrifugal loads at the RCP normal operation speed, design overspeed and joint-release speed are obtained using the finite element method (FEM), where release of the deformation-controlled stresses as a result of structural interactions during rotation is considered. Fracture mechanics evaluations for a series of cracks assumed to exist in the flywheel are conducted, considering ductile (fatigue) and non-ductile fracture, and stress intensity factors are obtained for the cracks using the finite element alternating method (FEAM). From analysis results, it is found that fatigue crack growth rates calculated are negligible for smaller cracks. Meanwhile, the material resistance to non-ductile fracture in terms of the critical stress intensity factor (K$_{IC}$) and the nil-ductility transition reference temperature (RT$_{NDT}$) are governing factors for larger cracks.

Keywords

References

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