海洋环境下浮动核电站堆内燃料组件结构安全分析

针对海洋环境下浮动核电站堆内燃料组件的结构安全问题，结合水动力学和结构力学，考虑燃料组件在堆内作业和海上换料两种状态，以及海洋环境下船体随机运动响应的影响，对燃料组件的结构载荷进行计算，从而校核燃料组件在堆内作业时的结构安全，并为实施海上换料作业的可行性提供理论依据。以海洋核动力平台为例，首先对平台进行时域计算，得到船体重心的六自由度运动时历曲线，然后采用远程位移方法将船体运动传递到反应堆，实现对反应堆随船体运动的数值模拟，进而对燃料组件的应力、应变最大值进行求解。结果表明，与船体静止状态下相比，燃料组件的应力、应变最大值在船体运动状态下明显增大，说明在对浮动核电站堆内燃料组件进行结构安全分析时必须考虑海洋环境下船体的随机运动响应。

Structural Safety Analysis of Fuel Assembly for Floating Nuclear Plant under Marine Environment

In order to analyze the structural safety of fuel assembly for floating nuclear plant under marine environment, the structural loads of fuel assembly in two states of working in reactor and refueling at sea were researched by means of combining hydrodynamics and structural mechanics. Taking the ship random motion response under marine environment into account, the structural safety of fuel assembly working in reactor was checked and the theoretical basis for the feasibility of implementing refueling operation at sea was provided. Taking the marine nuclear power platform as an example, firstly the time domain simulation aiming at platform was conducted to obtain the time serial curves of center of gravity in six degrees of freedom, and then remote displacement method was adopted to transfer the ship motion to the reactor to realize the numerical simulation of reactor moving with the ship, and the maximum values of stress and strain of fuel assembly were calculated finally. The results show that the maximum values of stress and strain of fuel assembly increase obviously in ship moving state compared with in static state, which explains that it is quite essential to consider the ship random motion response during the structural safety analysis of fuel assembly.