海洋条件下自然循环铅铋反应堆偏环运行特性分析

基于二次开发RELAP5/MOD3.1程序，分析了典型海洋条件下的10 MW自然循环铅铋反应堆偏环运行特性。分析结果表明:反应堆在倾斜条件下偏环运行时，其系统参数对倾角变化敏感性较弱；起伏条件下，偏环运行导致流量的波动幅度降低为9%，出口温度降低约16 K。起伏幅度越大、流量波动越剧烈；起伏周期越大、流量震荡越明显，但影响效果也在减弱；摇摆条件下，堆芯流量、出口温度降低，反应堆引入更高的安全裕量；摇摆幅度越大、摇摆周期越小，流量波动幅度越大，且堆芯出口温度对周期变化敏感性明显高于摇摆幅度变化。

Asymmetrical operation characteristics of natural circulation lead-bismuth reactor under ocean conditions

To ensure the vitality of naval nuclear power at all times, the natural cycle lead-bismuth reactor loop will take partial loop operation when it fails under marine conditions. However, there are few studies on the partial loop operation characteristics of lead-bismuth reactor under marine conditions. Based on the secondary development of RELAP5/MOD3.1 program, the off-loop operation characteristics of a 10 MW natural cycle lead-bismuth reactor under typical oceanic conditions are analyzed. The analysis results show that the system parameters of the reactor are less sensitive to the change of tilt angle when the reactor is operating under inclined conditions. Under undulating conditions, the fluctuation of flow rate is reduced by 9% and the outlet temperature is reduced by about 16 K. The larger the undulating amplitude, the more drastic the flow rate fluctuation; the larger the undulating period, the more obvious the flow rate oscillation, but the effect is also weakening. Under rocking conditions, the core flow and outlet temperature are reduced and the reactor introduces higher safety margins. The larger the swing amplitude and the smaller the swing period, the larger the flow fluctuation, and the core outlet temperature is significantly more sensitive to the cycle change than the swing amplitude change.