湛江口岸进出口水产品的放射性监测分析

Radioactive monitoring of import and export aquatic products at Zhanjiang port

中文关键词:  水产品  放射性  γ辐射剂量率

英文关键词:aquatic products  radioactivity  γ radiation dose rate

中文摘要:

      目的 应用NaI(Tl)低本底γ谱仪和高纯锗γ谱仪监测水产品中放射性核素的方法对湛江口岸进出口水产品中的核污染情况进行监测。方法 采用3种方法分别得到样品中131I、134Cs、137Cs 3种核素的比活度, 并对待测样品进行特定时期监控。方法1: 样品烘干、切片直接进样到NaI(Tl)低本底γ谱仪; 方法2: 样品烘干、经微波灰化系统灰化后进样到NaI(Tl)低本底γ谱仪; 方法3: 样品烘干、经微波灰化后进样到高纯锗γ谱仪。结果 方法1监测2011~2013年自日本进口的19批水产品, 其监测结果均在检测限以下(检测限均为10 Bq/kg); 方法2监测2014年自日本进口5批次水产品, 其监测结果均在检测限以下(检测限均为0.5 Bq/kg); 方法3监测2015年进出口水产品共13批次, 其监测结果与本底值相当(131I、134Cs、137Cs空白本底值为3 mBq/kg)。结论 利用微波灰化进样到高纯锗γ谱仪对水产品3种核素的检测效果最好。通过对湛江口岸近5年来进出口水产品放射性核素的监测分析, 尚未发现受放射性核素污染的水产品。

英文摘要:

      Objective To monitor the radionuclide pollution situation in aquatic products imported and exported by Zhanjiang port by NaI (Tl) low background γ spectrometer and HPGe γ spectroscopy instrument. Methods The specific activities of 3 kinds of radionuclides including 131I, 134Cs and 137Cs in samples were determined by 3 kinds of detection methods, and samples were monitored during a particular period. The first method was as follows: samples were dried, sliced and directly injected into NaI (Tl) low background γ spectrometer; the second method was as follows: samples were dried, and processed by microwave ashing system and then injected into NaI (Tl) low background γ spectrometer; the third method was as follows: samples were dried and processed by microwave ashing system and then injected into HPGe γ spectroscopy instrument. Results The monitoring results of 19 batches of aquatic products imported from Japan in 2011~2013 by the first method were below the detection limit of 10 Bq/kg. The monitoring results of 5 batches of aquatic products imported from Japan in 2014 by the second method were below the detection limit of 0.5 Bq/kg. The monitoring results of 13 batches of aquatic products in 2015 by the third method were equivalent to the background value of 3 mBq/kg. Conclusion The detection effect of 3 kinds of radionuclides by using microwave ashing sample and HPGe γ spectrometer was the best. Import and export of aquatic products have not yet appeared nuclear pollution phenomenon in Zhanjiang port in recent 5 years.