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用热重法测量加热Gd_2O_3-UO_2烧结芯块,研究其吸湿性。实验结果证明:高密度、低开口孔隙率(≤0.2％)的Gd_2O_3-UO_2芯块暴露在相对湿度为40％～90％空气中吸附的水是可以忽略不计的,并在室温真空条件下就很容易除去;具有特别高开口孔隙率(2％)的芯块中的吸附水可以通过线性升温至150℃保温1.5h以上除去;而芯块中“茶壶状”或称“墨水瓶状”深孔中的水及制备过程中带进的强力化学结合水要到400℃以上才能释放。除气后的Gd_2O_3-UO_2芯块中含水量远低于10μg/g,满足芯块含水量不超过15μg/S的技术要求。可以避免由于芯块水分含量超标致使锆合金包壳管氢脆所造成的燃料棒破损。
The Gd 2 O 3 -UO 2 sintered pellets were heated and measured by TG method to study the hygroscopicity. The experimental results show that Gd 2 O 3 -UO 2 pellets with high density and low open porosity (≤0.2%) are negligible when exposed to air with relative humidity of 40% -90%, and they are neglected at room temperature under vacuum It is easy to remove; the adsorbed water in pellets with a particularly high open porosity (2%) can be removed by a linear ramp up to 150 ° C for 1.5 h, while the “teapot” or “ink bottle” Hole in the water and the preparation process into the strong chemical water to more than 400 ℃ to release. The gas content of Gd_2O_3-UO_2 pellets after degassing is much lower than 10μg / g, which meets the technical requirement that the moisture content of pellets does not exceed 15μg / S. Can avoid the moisture content of the pellets caused by the zirconium alloy cladding tube hydrogen embrittlement caused by broken fuel rods.