基于燃料组件振动分析软件FAVA的水隙变化研究

Study on Fuel Assembly Gap Change Behavior Based on Fuel Assembly Vibration Analysis Software FAVA

燃料组件振动引起的燃料组件之间水隙变化对反应堆内功率波动具有重要影响.为了研究燃料组件振动和水隙变化行为,根据燃料组件结构及其振动特点建立了燃料组件振动分析模型,并开发了燃料组件振动分析软件FAVA.首先,通过与商用有限元软件Abaqus对比,对燃料组件振动分析模型进行了验证;其次,通过分析燃料组件振动引起的水隙变化,比较FAVA软件计算的燃料组件振动频率与堆芯功率波动频率,说明了堆芯功率波动主要是由燃料组件振动引起的;最后,分析了燃料组件刚度变化对振动的影响.

The change of water gap in fuel assembly caused by fuel assembly vibration has an important influence on the power fluctuation in the reactor.In order to study the behavior of fuel assembly vibration and water gap variation,fuel assembly vibration analysis model is established according to fuel assembly structure and its vibration characteristics,and fuel assembly vibration analysis software FAVA is developed.Firstly,the fuel assembly vibration analysis model is validated by comparing with the commercial finite element software Abaqus.Secondly,by analyzing the change of water gap caused by fuel assembly vibration,the fuel assembly vibration frequency calculated by FAVA software is compared with the core power fluctuation frequency,which shows that the core power fluctuation is mainly caused by the fuel assembly vibration.Finally,the influence of stiffness change of fuel assembly on the vibration is analyzed.