Title
Large-eddy simulation, fuel rod vibration and grid-to-rod fretting in pressurized water reactors.
Abstract
Grid-to-rod fretting (GTRF) in pressurized water reactors is a flow-induced vibration phenomenon that results in wear and fretting of the cladding material on fuel rods. GTRF is responsible for over 70% of the fuel failures in pressurized water reactors in the United States. Predicting the GTRF wear and concomitant interval between failures is important because of the large costs associated with reactor shutdown and replacement of fuel rod assemblies. The GTRF-induced wear process involves turbulent flow, mechanical vibration, tribology, and time-varying irradiated material properties in complex fuel assembly geometries. This paper presents a new approach for predicting GTRF induced fuel rod wear that uses high-resolution implicit large-eddy simulation to drive nonlinear transient dynamics computations. The GTRF fluid-structure problem is separated into the simulation of the turbulent flow field in the complex-geometry fuel-rod bundles using implicit large-eddy simulation, the calculation of statistics of the resulting fluctuating structural forces, and the nonlinear transient dynamics analysis of the fuel rod. Ultimately, the methods developed here, can be used, in conjunction with operational management, to improve reactor core designs in which fuel rod failures are minimized or potentially eliminated. Robustness of the behavior of both the structural forces computed from the turbulent flow simulations and the results from the transient dynamics analyses highlight the progress made towards achieving a predictive simulation capability for the GTRF problem. A new approach for predicting grid-to-rod fretting wear in reactor fuel is presented.ILES validation is performed using data for a 5 × 5 fuel rod bundle.Richardson extrapolation of statistical fuel rod forces is used to bound wear work-rates.
Year
DOI
Venue
2016
10.1016/j.jcp.2016.06.042
J. Comput. Physics
Keywords
Field
DocType
Thermal-hydraulics,Nuclear reactor,Rod-bundles,Grid-to-rod fretting,Implicit large-eddy simulation,Nonlinear structural dynamics,Incompressible flow,Monotonicity-preserving advection
Tribology,Nuclear reactor core,Fretting,Thermal hydraulics,Nuclear reactor,Large eddy simulation,Mathematical analysis,Vibration,Rod,Mathematics,Nuclear engineering
Journal
Volume
Issue
ISSN
322
C
0021-9991
Citations 
PageRank 
References 
1
0.37
1
Authors
6
Name
Order
Citations
PageRank
Mark Christon161.46
Roger Lu210.37
J. Bakosi362.05
Balasubramanya T. Nadiga471.94
Zeses Karoutas510.37
Markus Berndt65812.06