TY - JOUR

T1 - DETERMINATION OF 239,240PU IN CASPIAN SEA WATER USING THE SORPTION–DIFFUSION MODEL OF THE RADIONUCLIDE UPTAKE BY BOTTOM SEDIMENTS

AU - Бакунов, Николай Александрович

AU - Аксенов, Алексей Олегович

PY - 2024/8/1

Y1 - 2024/8/1

N2 - Abstract: The content of global 239,240Pu in Caspian sea water (1996–2056) was calculated using the sorption–diffusion model of the radionuclide uptake by bottom sediments with the distribution coefficient Kd = 50 × 103 and diffusion coefficient D = 0.1 × 10–7 cm2/s. The 239,240Pu global fallout on the sea was assumed to be equal to the experimental value for the mid-latitude belt of Russia, 60 Bq/m2. At the plutonium fallout density on the sea surface of 58 Bq/m2, its inventory in the sea Q as of the year 1964 is 21.9 TBq. In 1996, the experimentally determined 239,240Pu concentration in Caspian sea water was ~20 μBq/L, and the calculation by the model gives 17.8 μBq/L. During the ~30-year migration of global 239,240Pu, about 93% of the radionuclide passed from the aqueous phase to bottom soils. According to the calculations, the 239,240Pu concentration in the seawater in the period 1996–2056 will decrease from 17.8 to 10.5 μBq/L, and the 239,240Pu inventory in the seawater, from 6.3 to 3.7%, of the fallout value. The results were verified using an independent method for 90Sr monitoring in Caspian sea water and determining the 239,240Pu/90Sr concentration ratio in the water. The results of estimating the 239,240Pu concentrations in the seawater (2017–2020) by these two methods reasonably agree with each other.

AB - Abstract: The content of global 239,240Pu in Caspian sea water (1996–2056) was calculated using the sorption–diffusion model of the radionuclide uptake by bottom sediments with the distribution coefficient Kd = 50 × 103 and diffusion coefficient D = 0.1 × 10–7 cm2/s. The 239,240Pu global fallout on the sea was assumed to be equal to the experimental value for the mid-latitude belt of Russia, 60 Bq/m2. At the plutonium fallout density on the sea surface of 58 Bq/m2, its inventory in the sea Q as of the year 1964 is 21.9 TBq. In 1996, the experimentally determined 239,240Pu concentration in Caspian sea water was ~20 μBq/L, and the calculation by the model gives 17.8 μBq/L. During the ~30-year migration of global 239,240Pu, about 93% of the radionuclide passed from the aqueous phase to bottom soils. According to the calculations, the 239,240Pu concentration in the seawater in the period 1996–2056 will decrease from 17.8 to 10.5 μBq/L, and the 239,240Pu inventory in the seawater, from 6.3 to 3.7%, of the fallout value. The results were verified using an independent method for 90Sr monitoring in Caspian sea water and determining the 239,240Pu/90Sr concentration ratio in the water. The results of estimating the 239,240Pu concentrations in the seawater (2017–2020) by these two methods reasonably agree with each other.

KW - 239,240Pu

KW - concentration

KW - diffusion

KW - sorption

KW - water

UR - https://www.mendeley.com/catalogue/f34ba411-a244-3339-92a4-f044b4f45464/

U2 - 10.1134/s1066362224040180

DO - 10.1134/s1066362224040180

M3 - Article

VL - 66

SP - 570

EP - 575

JO - Radiochemistry

JF - Radiochemistry

SN - 1066-3622

IS - 4

ER -