植物样品中有机氚测量方法的初步研究

Preliminary Study on Determination Methods for Organically Bound Tritium Activity in Plant Sample

为研究植物样品中有机氚(OBT)浓度相关测量的最佳方法,以秦山核电基地所采植物和人为氚污染的植物样品为研究对象,对去除交换性有机氚(E-OBT)所需的最合适浸泡水用量和浸泡时间及样品氧化燃烧和收集过程中氚的残留效应进行了研究。结果表明:用30倍于干物质质量的低氚水浸泡24h,可有效去除植物样品中的E-OBT;用50mL低氚水冲洗氧化燃烧炉1次,即可将残留在其中的氚冲洗干净;经3次大量低氚水冲洗后OBT水样收集瓶与石英舟中无氚残留。

In order to investigate the best determination methods for organically bound tritium（OBT）activities,the plant samples in the vicinity of Qinshan nuclear power base and the plant samples intentionally contaminated were collected.The most suitable volume of immersion water and immersion time to extract most exchangeable organically bound tritium（E-OBT）,the effect of tritium residue during combustion of dry plant samples and collection of combustion water were studied.The results show that the most suitable mass proportion between immersion water with low-level activity tritium and dry sample is 30 times,and the immersion time is 24 hfor the effective elimination of E-OBT by isotopic exchange.The tritium residue in combustion apparatus is completely cleared with 50 mL water.There is no tritium residue in the collection bottle of OBT and quartz boat after washing 3times with large volume of water.