空气氚个体防护的高效氚过滤方法研究

Tritium is a radioactive isotope of hydrogen with low radioactive toxicity, which is not the only release of concern at nuclear facilities but the most released artificial radionuclide. Many investigations on the internal dose and hazard induced by tritium to the occupation exposures and public have been done in the world. It is necessary to improve the protection of internal exposure of tritium to the rapid increased radiation workers as many new nuclear power plants and nuclear facilities are built in China. The majority of tritium more than 99% in the air at the occupational workplace of high tritium concentration and ambient environment exists as tritiated water (HTO). The inhalation path of tritiated water in the all modes of intake is the crucial way for the workers exposured to tritium at nuclear plants and other nuclear facilities. New filtering method and technology are expected to reduce tritiated water intake. Molecular sieve filter and ice packed respirator have been widely used by the workers at the high tritium concentration workplace, unfortunately，both of them can work less than one hour and have many other limitations. Hydrogel is expected to be used as HTO filter material due to its powerful water absorptivity. This project is devoted to study new method and mechanism of irradiation synthesis of hydrogel with nontoxicity, super absorbent, low price and long life for practical use. Futhermore, the hydrogel synthesized by irradiation should remain air gaps and path for inhalation air to pass through and to reduce HTO intake when enough water is absorbed.

氚是低毒放射性核素，但却是核设施向工作场地和环境释放的活度最大的人工核素,其对辐射工作人员与公众产生的内照射剂量及健康危害的研究在国际上日益受到重视。随着积极发展核电政策的实施及核能核技术的其它应用，国内氚职业照射人群不断扩大，加强氚致内照射防护研究有着急迫的现实需求。氚浓度较高的工作场地空气中99％的氚为气态氚化水HTO分子，而工作人员体内氚的关键摄入途径为呼吸，项目拟探索呼吸过程HTO的过滤与去除新技术与方法。目前国内外最常使用的空气氚过滤器有分子筛过滤器与冰盒过滤器两种，它们对HTO都有较强的过滤效果，但使用时间较短，一般不超过1小时,另外，还有其它缺点。水凝胶材料具有强吸水性能，可望制成氚过滤材料。项目拟研制无毒、强吸水、廉价、吸收一定水量后仍具有密集缝隙、呼吸气流通畅、有效使用时间较长的凝胶材料的辐射制备方法与技术，并探索相关制备技术的理论与除氚机理。

氚是低毒放射性核素，但却是核设施向工作场地和环境释放的活度最大的人工核素,其对辐射工作人员与公众产生的内照射剂量及健康危害的研究在国际上日益受到重视。随着积极发展核电政策的实施及核能核技术的其它应用，国内氚职业照射人群不断扩大，加强氚致内照射防护研究有着急迫的现实需求。氚浓度较高的工作场地空气中99％的氚为气态氚化水HTO分子，而工作人员体内氚的关键摄入途径为呼吸。本项目主要研究内容是研制无毒、强吸水、廉价、吸收一定水量后仍具有密集缝隙、呼吸气流通畅、有效使用时间较长的凝胶材料，并探索相关制备技术的理论与除氚机理。项目总计研发了三种新型的吸附材料，并且对于现有的吸附材料性能进行了系统的表征，并搭建了一套氚化水的吸附测试装置，可以准确的测量材料的吸附性能。最后根据实验的数据对水凝胶材料的吸附原理进行了一定的分析。实验结果显示：水凝胶材料可以有效吸附氚化水，并且可以实现无毒、舒适的要求，但是结构容易发生坍塌，影响气流的通过；而引入碳纳米管或石墨烯可以有效的提高水凝胶的强度，可以在吸附氚化水后依然保持良好的结构框架，维持气流的通畅，并且可以提高材料的比表面积，更好提高材料的吸附性能。其中合成的碳纳米管复合水凝胶材料显示出比较突出的氚化水持续吸附能力，并且具有比表面积高，吸附能力强的性能，可满足现阶段防护材料的要求。另外机理分析显示，水凝胶材料对氚化水的吸附能力，不仅仅是物理吸附，还包括同位素交换效应，这对于后期氚化水吸附材料的制备具有重要的借鉴意义。