Concentration and characterization of plutonium in soils of Hubei in central China.
To study the Pu concentration and isotope ratio distributions present in China, the (239+240)Pu total activities and (240)Pu/(239)Pu atom ratios in core soil samples from Hubei Province in central China were investigated using Accelerator Mass Spectrometry (AMS). The activities ranged from 0.019 to 0.502 mBqg(-1) and the (239+240)Pu inventories of 45 and approximately 55 Bqm(-2) agree well with that expected from global fallout. The (240)Pu/(239)Pu atom ratios in the soil ranged from 0.172 to 0.220. The ratios are similar to typical global fallout values. Hence, any close-in fallout contribution from the Chinese nuclear weapons tests, mainly conducted in the 1970s, must have either been negligible or had a similar (240)Pu/(239)Pu ratio to that of global fallout. The top 10 cm layer of the soil contributes approximately 90% of the total inventory and the maximum concentrations appeared in the 2-4 cm or 4-6 cm layers. It is suggested that climatic conditions and organic content are the two main factors that affect the vertical migration of plutonium in soil.
Dong
Wei
W
State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China.
Tims
Stephen G
SG
Fifield
L Keith
LK
Guo
Qiuju
Q
D002681:China; D005843:Geography; D011005:Plutonium / Q000032:analysis*; D011834:Radiation Monitoring; D011847:Radioactive Fallout / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
D011847:Radioactive Fallout; D012990:Soil Pollutants, Radioactive; D011005:Plutonium