On Global 137Cs Diffusion in Bottom Sediments of Northern Seas.

Autor: Bakunov, N. A., Bolshiyanov, D. Yu., Aksenov, A. O., Makarov, A. S.
Předmět:
Zdroj: Radiochemistry; Aug2023, Vol. 65 Issue 4, p485-492, 8p
Abstrakt: In bottom sediments (BSs) of the Laptev and Kara Seas, 137Cs migrated for ~30 years with diffusion coefficients (D) n×(10–9–10–8) cm2/s. In the sediment profile between the soil layers, the 137Cs concentration gradient was preserved. The trend of decreasing concentration from the upper to the lower layers of the core was not violated along the entire path of radionuclide migration. 137Cs migrated into the BS slowly. About 20% of 137Cs remained in the upper (0–1 cm) soil layer. In the Tsivolki Bay of the Novaya Zemlya Archipelago 137Cs migrated at an extremely low temperature of (–1.0 –1.2)°C of the bottom waters and soils. The 137Cs concentration in the upper (0–1 cm) layer of the Laptev Sea and Tsivolki Bay sediments was characterized by close values, 7–18 Bq/kg and 14–24 Bq/kg, corresponding to the global level of soil contamination. The Tsivolki Bay is ice-covered for 10 months. 137Cs profile in BS cores was formed due to radionuclide diffusion in conditions of a short warm period of terrigenic sedimentation. 137Cs concentration in the bay sediments and the type of the concentration profile in the cores demonstrated an absence of radionuclide release from buried radioactive objects in the bay. 137Cs diffusion coefficients determination computed with experimental data will be necessary in models of radionuclide migration in water bodies and scientifically supported measures to minimize damage from the impact of the radiation factor. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index