Concentration and characterization of plutonium in soils of Hubei in central China

Plutonium in Soils from Northeast China and Its Potential Application for Evaluation of Soil Erosion

“…The measured 240 Pu/ 239 Pu atomic ratios in all soil samples in this work agreed very well with the reported values of the global fallout as well as those in similar latitude in China, such as soil samples from Gansu province (40°N, 97° E) of 0.169 ~ 0.192 with an average of 0.182 ± 0.008 (1σ)29, and from Hubei province (31°N, 112°E) of 0.172 ~ 0.22030. Similar 240 Pu/ 239 Pu atomic ratios of 0.157 ~ 193 with an average of 0.182 ± 0.012 (1σ) have also been reported in a sediment core collected in Lake Sihailongwan, northeast China (42°20′N, 126°50′E)33.…”

“…Based on the depth profile of Pu in the DL-01 soil core, the estimated total inventory of 239 + 240 Pu of 86.9 ± 3.1 Bq/m 2 (Table 1) agreed very well with those reported values in soil profiles in similar latitude (30 ~ 40°N) in Korea (84 ~ 88 Bq/m 2 )24. A slightly higher 239 + 240 Pu inventory (101.8 Bq/m 2 ) in Euiwang, Korea24, lower values in Hubei (44.9 ~ 54.6 Bq/m 2 )30 and Lanzhou (32.4 Bq/m 2 )29 in China have also been reported. The deviation of 239 + 240 Pu inventory in the DL-01 core from those values might be attributed to the differences in the locations and climate of specific location.…”

“…Nonetheless, quantification of soil erosion using Pu isotopes has not yet been well established up to date, and very few baseline data of Pu isotopes have been reported22232425. Although concentrations of Pu isotopes in surface soils have been measured in many sites worldwide in the past 40 years232627, a few works on Pu distribution in Chinese soils (less than 15 sampling sites, mainly surface soils) have been reported282930 and no data of Pu isotopes in soils from northeast China is available.…”

Quantifying sources of fine sediment supplied to post-fire debris flows using fallout radionuclide tracers

“…239,240 Pu represent viable alternative tracers to 137 Cs in the long-term because of the much longer half lives of these Pu isotopes and the decline in 137 Cs levels due to decay, particularly in the southern hemisphere where fallout of 137 Cs was less than the northern hemisphere (Moroney, 1979;Tims et al, 2010). In undisturbed forest environments, soil depth profiles of each of the radionuclides tend to decrease exponentially down the profile, with maximum concentrations at the soil surface for 210 Pb ex and slightly below the surface for 137 Cs and 239,240 Pu (Wallbrink and Murray, 1996;Wallbrink et al, 2002;Dong et al, 2010;Hoo et al, 2011).…”

Plutonium and uranium contamination in soils from former nuclear weapon test sites in Australia

“…Studies such as these have in the past commonly used 137 Cs as the tracer isotope [2]. Plutonium, with a similar depositional history and fallout origin as 137 Cs, a similar vertical migration rate in most surface soil types and sediments as 137 Cs [3] (though certain soil compositions, climatic conditions and chemical forms of source material can lead to higher migration rates for Pu compared to Cs [4,5]) and with significantly longer half life ( 239 Pu and 240 Pu have half lives of 24100 and 6560 years, respectively, compared to 137 Cs which has only a 30.07 year half life) is increasingly being used in geomorphological studies such as determination of soil or sediment source materials [6][7][8] and sedimentation determination [9]. Since the peak of atmospheric nuclear testing in 1963, nearly two half lives of 137 Cs have now passed and consequently it is increasingly difficult to detect 137 Cs with high precision in sediments and soils, especially where sample sizes are small.…”