The paper presents a complex modelling concept for the nuclear fuel assembly vibration caused by the coolant pressure pulsations generated by the main circulation pumps. The method is based on the two-stage modelling with the reactor’s global model at the first stage and the detailed model of the particular fuel assembly at the second stage. This approach allows respecting all the relevant mechanical nonlinearities — clearances and friction in the key-groove couplings between the reactor core barrel and the pressure vessel and the internal impact or the friction interaction of the fuel assemblies. Numerical simulations allow better interpretation of monitoring data concerning the fuel burn-up.

该论文提出了一个由主循环泵产生的冷却剂压力脉动引起的核燃料组件振动的复杂建模概念。该方法基于两阶段建模，第一阶段是反应堆的全局模型，第二阶段是特定燃料组件的详细模型。这种方法允许考虑所有相关的机械非线性——反应堆芯筒和压力容器之间键槽耦合中的间隙和摩擦，以及燃料组件的内部冲击或摩擦相互作用。数值模拟允许更好地解释关于燃料燃烧的监测数据。