【摘要】 大气中氚主要以氚化水（HTO）、氚化氢（HT）以及氚化甲烷（CH₃T）的形态存在,其危害与其化学形态相关。为了准确评价核设施周围大气中不同化学形态的氚水平,基于高温催化氧化和低温冷阱捕集的原理,建立了一套适用于核设施周围大气中多形态氚的取样及测量方法,并对秦山核电站周围大气中不同形态氚进行了初步测量。该方法中催化剂在大气环境下对HT和CH₃T的催化氧化效率≥99%,冷阱对水样的收集效率≥95%,具备了同时采集和测量HTO、HT和CH₃T的功能。基于秦山核电站周围大气中氚的初步测量结果发现:秦山核电站周围大气中存在HTO、CH₃T和HT三种形态的氚,且HTO>CH₃T>HT,CH₃T和HT浓度与环境本底水平相当,由此表明,建立的取样和测量方法有较高的灵敏度,可以用于核设施周边大气中环境水平氚的采样测量。更多还原

【Abstract】 [Background] Tritium in the atmosphere exists mainly as tritiated water（HTO）, tritiated hydrogen（HT） and tritiated methane（CH₃T）. Radiation hazard of tritium is related to its chemical form. Atmospheric tritium in these three chemical forms should be measured simultaneously in the vicinity of nuclear facilities. [Purpose] This study aims to evaluate the level of atmospheric tritium in these three chemical forms accurately. [Methods] Based on the principle of high temperature catalytic oxidation and low temperature cold trap collection, a novel atmospheric tritium sampling system and measurement method were developed. Catalytic efficiencies for hydrogen and methane at different temperatures were measured. Concentrations of hydrogen and methane that needed were evaluated. And the concentrations of atmospheric tritium in the vicinity of Qinshan nuclear power plant（QNPP） were preliminary measured. [Results] Catalytic efficiencies for hydrogen and methane by using self-developed atmospheric sampling system could up to be about 99%, and water vapor collecting efficiency could be more than 95%. The concentrations of atmospheric tritium in the vicinity of QNPP, displayed in a decreasing order, were HTO, CH₃T and HT. [Conclusion] The novel atmospheric tritium sampling system had the ability to collect HTO, HT and CH₃T simultaneously. Atmospheric tritium in forms of HTO, HT and CH₃T were firstly measured in the vicinity of QNPP. The concentrations of HT and CH₃T measured were comparable to the background levels, which indicated that the sampling system and measurement method in this paper had a very high sensitivity and could be applied to atmospheric tritium sampling within environmental levels in different forms.更多还原