制备125I的堆照循环回路模拟系统调试

利用中国先进研究堆（CARR）辐照制备¹²⁵I的循环回路为全封闭的不锈钢细长管路系统。在入堆安装使用前，需对系统进行严格的调试实验，并测试系统的密封性，使其满足设计要求。本研究根据CARR的场所条件要求，设计¹²⁵I制备循环回路模拟系统并进行调试，包括真空调试和氙气充气收气实验。采用长管路分段调试验证系统真空度并测定真空泄漏率；系统安装调试合格后，充入不同压力的天然氙气进行循环回收模拟实验。结果表明，设计的¹²⁵I循环回路系统为细长多弯曲管路，系统密封性好，经氦质谱检漏测定值小于10^-6 Pa•m³/s；天然氙气在系统中的导气实验结果表明，回收时间约为120 s，符合堆照生产¹²⁵I的要求。实验结果证实了系统入堆安装调试的可行性，可为建立反应堆辐照制备¹²⁵I回路系统提供参考。

Commissioning for 125I Production Loop Simulation System by Reactor Irradiation

The loop system for iodine-125 production by China Advanced Research Reactor (CARR) was a set of device which was fully enclosed and long pipe system that made by stainless steel. The system must be strict installation and debugging before installation in the reactor, and it need to leak detection as well to ensure design requirements. According to the requirements of the place of CARR, the designing and debugging simulation system was primarily focused, mainly including the system’s installation, vaccum debugging and Xenon gas recovery test. The methods of subsection debugging for long pipeline and guiding gas test with the pipe system were carried out. After the installation and commissioning of the system, recovery simulation experiment of natural abundance of xenon was also carried out. The results showed that the I-125 simulation loop was a slender and multi bending pipeline. The system had good sealability and the measured value less than 10^-6 Pa•m³/s of leak detection by helium mass-spectrometer leak detector. It took 120 seconds to recover the guiding natural Xenon,which could meet the design requirements . The system scheme was feasible and provided the basis for further iodine-125 production of loop circuit method by reactor.