中文摘要：

以200kW空间快堆RAPID-L为对象，建立瞬态分析模型，分析在无保护超功率事故UTOP和无保护失流事故ULOF下的瞬态特性。计算结果表明：快速型锂膨胀模块（LEM）可随冷却剂温度变化自动快速响应，能够在不停堆情况下保证反应堆的安令，因此，RAPID-L具有固有安全特性。

英文摘要：

The transient analysis model for the 200 kW Advanced Space Fast Reactor RAPID-L was developed. The unprotected transient overpower（UTOP） and unprotected loss of flow（ULOF） were analyzed by this model. It is demonstrated that the quick lithium expansion module（LEM） can response promptly according to the coolant temperature variation and safeguard the reactor without shut-down, so RAPID-L has the characteristics of inherent safety.