针对医院中子照射器I型堆（IHNI-1）的堆芯特点和运行工况，建立了适用于IHNI-1反应堆堆芯的热工分析模型，并对模型进行了验证。利用所建模型，计算了IHNI-1反应堆堆芯热工参数。最后分析了IHNI-1反应堆堆芯入口流量对堆芯出口温度的影响，同时给出了堆芯发生过冷沸腾时的功率计算结果。

According to the characteristics and operation condition of IHNI-1 reactor, a subchannel model is developed in this paper. It also has been verified that the model is reasonable and effective in IHNI-1's thermal hydraulic analysis. Using the model, some thermal parameters of IHNI-1reactor are calculated. The relation between the core's coolant inlet flux and outlet temperature is analyzed, and the variation of rod temperature with reactor power is also calculated.