Fukushima Nuclear Accident Impact On The Haiyang NPP Background Survey

Objectives:To grasp the Fukushima nuclear accident impact on the Haiyang NPP background survey.Methods:Measure the aerosol, fallout and air131I samples,which regular collect from5fixed measuring points around the Haiyang NPP,from2010December to2011June,and continuous measure the y dose rate at5fixed measuring points.1.Use high flow sampler to collect the aerosol samples,use medium flow sampler to collect the air131I, use of the basin to collect fallout samples;2.Use Model919E HPGe y spectrometer to measure the134Cs,137Cs,58Co,60Co,54Mn,103Ru and110mAg radioactivity level in the aerosol and fallout,and the air131I radioactivity level;3.Use BH1216low-background α and β detector to measure the totle a and totle β,90Sr radioactivity level in the aerosol and fallout;4.Use YB-IV y dose rate detector to continuous measure the y dose rate at5fixed measuring points;5.Compare the samples measure datum before and after the accident,to analysis the Fukushima nuclear accident impact on the Haiyang NPP background survey.Results:1.At the second mouth after the accident monitor134Cs and137Cs in the aerosol samples,134Cs in the range of58.2～85.7μBq/m3, the mean was74.9μBq/m3,137Cs in the range of19.8～68.3μBq/m3, the mean was46.3μBq/m3;at the same month and second month after the accident monitor90Sr, it in the range of27.6～48.6μBq/m3, the mean was38.3μBq/m3; totle a and totle β has no obvious change; 58Co,60Co,54Mn,103Ru and110mAg were not detected.2.1n the fallout samples after the accident measure the137Cs in the range of0.08～0.20Bq/(m2.M), the mean was0.14±0.05Bq/(m2.M);90Sr in the range of0.05～0.11Bq/(m2.M), the mean was0.076Bq/(m2.M); totle a and totle β has no obvious change;134Cs,58Co,60Co,54Mn,103Ru and110mAg were not detected.3.Air131I was not detected.from the samples after the nuclear accident, for haven’t timely measure.4. The continuous y radiation dose rate after the nuclear accident in15days,the data of Daxinjia Village in the range of80.1～81.7nGy/h,the mean was81.0nGy/h; the data of Zhaiqian Village in the range of65.6-66.8nGy/h,the mean was66.1nGy/h; the data of Haiyang EPA in the range of81.5-82.7nGy/h,the mean was82.4nGy/h.Conclusions:1. Fukushima nuclear accident impact on the Haiyang NPP background survey is mainly in the same month and second month.2. Fukushima nuclear accident impact on the Haiyang NPP background survey the main radionuclides are134Cs and137Cs in the aerosol,the second is137Cs in the fallout,and third is90Sr in the aerosol;3.The radionuclides58Co,60Co,54Mn,103Ru and110mAg,what were discharged by Fukushima nuclear accident,had no effect on the surrounding Haiyang NPP.The air131I radioactivity level less than2.16mBq/m3.