Static bending characteristic analysis of a PWR fuel assembly by experimental and finite element method

The objective of this research is to determine the lateral bending behaviour of a pressurized water reactor fuel assembly. To perform this objective, an experimental method and a finite element analysis method for predicting the lateral bending behaviour on a fuel structure using commercial finite element code ANSYS are established. In both methods, appropriate boundary conditions are applied to simulate the actual core conditions. The 40 mm lateral displacement of a fuel assembly for the PWR power plant is applied at the middle spacer grid position using the power screw jack in the test method. On the other hand, the finite element analysis is simulated the static lateral bending analysis, which is applied the rigid surface withstand the structure. The lateral bending characteristics has been investigated by obtaining the reaction force vs. lateral displacement. The analysis results were compared with the experimental results. The reaction forces at the uppermost and lowermost position were very similar with the test results. In addition to this, the maximum bending stress at the lowermost guide tube position was very good agreement with the test result, but the value of the uppermost position was much difference from the test result. After comparing these results with the test results, it was discussed on the basis of the 16 by 16 type fuel assembly. The developed finite element model and analysis procedure will be useful tools for evaluating the static behaviour of a fuel assembly. Finally, this analysis model will be used for safety analysis of a reactor core. (author)