微波碳化减容放射性废物尾气取样研究

RESEARCH ON EXHAUST SAMPLING OF RADIOACTIVE WASTE FROM MICROWAVE CARBONIZATION VOLUME REDUCTION

在微波碳化减容核电放射性废物过程中,将释放出HCl、H2、CO、CO2、二恶英等可燃或有毒气体,利用自行设计的负压状况下取样装置实现尾气样品的采集。通过对废物尾气取样分析,获得如下结论:尾气中氢气、甲烷和总烃等可燃气体的浓度小于4%的燃爆限值;在较高温度(200℃)以上,释放出CO和CO2气体,说明PVC裂解产生的残炭在高温段发生氧化反应,使得减容率和减重率进一步提高;通过控制升温程序可大大降低二恶英的产生,使尾气中二恶英的浓度低于排放标准一个数量级。

In the process of nuclear radioactive waste by microwave carbonization volume reduction,flammable or toxic gases such as HCl,H2,CO,CO2 and dioxin etc would release.The sampling device which work under vacuum condition by self-designed was used to collect the exhaust samples.Through the analysis of waste gas sampling,the following conclusions were got.The concentration of combustible gases of hydrogen,methane and total hydrocarbon in the exhaust gas is less than 4% of the deflagration limited value.At high temperature(200 ℃) above,CO and CO2 gas would release,and it was illuminated that the oxidation reaction of carbon residue from PVC cracking occurred in the high temperature,which had further increases of the volume reduction rate and weight loss rate.By controlling the temperature program could greatly reduced the generation of dioxin,and dioxin concentration in the exhaust was less than one order of magnitude of the emission standard.