Pu-241 in samples of forest soil from Poland

Fluvial Transport of Chernobyl Plutonium (Pu) to the Black Sea: Evidence from 240Pu/239Pu Atom Ratios in Danube Delta Sediments

“…The non-volatile actinides, along with nonvolatile fission products are contained in individual "hot" fuel particles of 1-10 μm aerodynamic diameter [14]; these particles have been previously identified in Poland [11][12][13][14] and in Finland [15,16]. The transport of "hot" fuel particles over distances of up to ~ 1000 km is evident in these previous studies [11][12][13][14][15][16]. Deposition of non-volatile Chernobyl particles into the Danube watershed occurred during the course of the accident; over subsequent years, material has been eroding from the catchment basin, entering the Danube River, and is thereafter transported towards the Black Sea.…”

Determining 241Pu in environmental samples: case studies in alpine soils

“…The Pu in all these sites has been shown to come from the NWTs. However, increased levels of 241 Pu in low altitude soils have been reported for regions also affected by radioactive fallout from the Chernobyl accident, such as in Poland [5] and in Ukraine [41].…”

“…For example, NWT fallout was characterized by a 241 Pu/ 239,240 Pu activity ratio of about 12-16 for the latitudes [40][41][42][43][44][45][46][47][48][49][50] • North in 1963 [1][2][3]. For Chernobyl deposition, in contrast, the 241 Pu activity was higher by a factor of around 70-100 than that of 239,240 Pu at the time of the accident [1,[3][4][5][6][7]. Weapons grade plutonium, which is another important source of Pu in the environment, is characterized by a much lower 241 Pu/ 239,240 Pu activity ratio of about 0.5-4 [8][9][10].…”

“…The indirect methods are mainly based on the 241 Am built up in Pu originally electrodeposited on stainless steel discs [3]. This method is hindered by a lack of accuracy in comparison to direct methods because of a high uncertainty and high detection limit [5], and it also requires a lengthy storage of the samples before the analysis [5,7]. Among the direct methods, low-level liquid scintillation counting (LSC) is most commonly used for quantifying 241 Pu [11][12][13][14][15].…”

“…However, a major drawback of ICP-MS is the high detection limit of 2-4 Bq/kg [17,20] 241 Pu, a high degree of radiochemical purification is required in order to eliminate interferences from other environmental radionuclides. This has been successfully achieved by separation and purification steps involving the use of ion chromatography or liquid-liquid extraction methods [5,12,13].…”