Thermomechanical analysis of fuel rods during transitory events using the RAMONA and FETMA codes

In National Institute of Nuclear Research, the fuel management system (FMS) has been used by long time to simulate the BWR operation in stationary state, as well as during a transitory event. To evaluate the thermomechanical behavior of a fuel element was created and interface between the FMS codes and the fuel element thermo mechanical analysis (FETMA) code properly developed and implemented. In this work, the results of thermomechanical behavior of fuel rods that compose the hot channel during the simulation of a transitory event of a BWR are shown. The transitory events considered in this work are a load rejection and failure in controller of feed water, which are events more important that can to occur in a BWR. The results show that during the developed conditions by both transitory events some failure is not presented in fuel rods. Also, that the transitory event of load rejection is more claimant in security terms that of controller failure of feed water. (Author)