| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 296242 | Nuclear Engineering and Design | 2014 | 7 Pages |
•Finite element model of CHASNUPP-1 fuel assembly produced, using Shell181 elements.•Non-linear contact and buckling analysis have been performed.•Structural integrity and stress measurement of fuel assembly is calculated.•Calculated stresses and deformations, are compared with test results.•Results of both studies are comparable, which validate finite element methodology.
Fuel assembly of the PWR nuclear power plant is a long and flexible structure. This study has been made in an attempt to find the structural integrity of the fuel assembly (FA) of Chashma Nuclear Power Plant-1 (CHASNUPP-1) at room temperature in air. Non-linear contact and buckling analyses have been performed using ANSYS 13.0, in-order to determine the FA's deformation behaviour as well as the location/values of the maximum stress intensity and stresses developed in axial direction under applied compression load of 7350 N or 1.6 g being the FA's handling load (Zhang et al., 1994). The finite element (FE) model comprises spacer grids, fuel rods, flexible contact between the fuel rods and grids’ supports system (springs and dimples) and guide thimbles with dash-pots and flow holes, in addition to the spot welds between spacer grids and guide thimbles, has been developed using Shell181, Conta174 and Targe170 elements. FA is a non-straight structure. The actual behaviour of the geometry is non-linear. The value of the perturbation force is related to the geometry of the model and/or the tolerance defined for the geometry. Therefore, a sensitivity study has been made to determine the appropriate value of an arbitrary perturbation load.It has been observed that FA deformation values obtained through FE analysis and experiment (SNERDI Tech Doc, 1994) under applied compression load are comparable and show linear behaviours. Therefore, it is confirmed that buckling of FA will not occur at the specified load. Moreover, the values of stresses obtained at different locations of the guide thimbles are also comparable with the stress values of the experiment determined at the same locations through strain gauges.Since the results of both studies (analytical and experimental) are comparable, therefore, validation of the FE methodology is confirmed. The SINT and stresses are less than the design stress limit of the materials used for the grid (ASTM, 2013), fuel rod (ASTM, 2002) and the guide thimble (ASTM, 2004). Therefore, the structural integrity criterion of CHASNUPP-1 FA is fulfilled safely.
