炭/炭复合材料对活化片辐照的影响

Effects of C/C composites on the irradiation of activation foil

根据钍基熔盐堆高温环境辐射测量需求,采用具有高温抗氧化Si C涂层的炭/炭复合材料作为待测活化片的载体材料,介绍了采用炭/炭复合材料作为辐照载体的优越性,对其进行了成分和热分析测试,并详细描述了带有炭/炭复合材料的一组活化片和不带有炭/炭复合材料的另一组活化片同时在铀氢锆脉冲堆的径向实验孔道中进行中子辐照的实验过程。通过比较两组活化片的单核反应率,详细分析了炭/炭复合材料对活化片辐照结果的影响。结果表明,载体采用涂层为Si C的炭/炭复合材料,并且壁厚为几个毫米时,对多种活化片的中子辐照结果影响很小,可以作为高温环境下辐照材料的载体。

Background： C/C composites coated with SiC were introduced for the irradiation measurement at high temperature in Thorium Molten Salt Reactor-Solid Fuel （TMSR-SF） due to their excellent performance as an irradiation carrier of activation foil. Purpose： This study aims at the effects of C/C composites to activation foils. Methods： Based on the characteristics and service environment of C/C composites, component test and thermos analysis were carried out by element gravimetric density （GD） and calorimeter respectively to verify whether they would have influence on the irradiation results. Neutron irradiation experiment for activation foils with/without C/C composites was performed in a horizontal radial hole of uranium zirconium hydride reactor. And the activation rates of mononuclear were calculated respectively. Results： Experimental results show that SiC coating is essential for C/C composites to enhance oxidation resistance. The activation rate of mononuclear with C/C composites was reduced slightly. When the thickness of C/C was of ram-level, the decrement of activation rate for mononuclear was less than 10%. Conclusion： C/C composites coated with SiC could be used as carrier materials for activation foils at high temperature when the carrier wall is thin. The results of irradiation could be corrected based on the measurement of C/C composites.