Strontium-90 transport parameters from source term to aquifer in the Chernobyl Pilot Site

Abstract

Results are presented from multidisciplinary radiological and hydrogeological studies of process and parameters controlling W ST releases from the shallow trench containing nuclear fuel particles and subsequent radionuclide transport in the underlying eolian and alluvial sand aquifer at Chernobyl Pilot Site located at 2.5 km distance from the Chernobyl NPP. Microscopic analyses of fuel particles separated from waste have identified two families of particles: U-0 and Zr-U-0 (-25% and 75% of the fuel particles respectively). The Zj-contaming particles exhibits low dissolution rate, therefore radionuclide inventory in source term available for migration is significantly less than estimated before. The w Sr migration velocity in the eolian sand layer is estimated at =7% of real groundwater flow velocity (K<f=3 ml/g). Alluvial sediments comprising the middle part of the aquifer have notably higher sorption capacity (Kj»20 ml/g), and may represent essential natural sorption barrier to geo-raigrarion. Radioactivity balance calculations show that 4 -7% of initial trench inventory of '"Sr has migrated by now to the geological environment. Presented results have important implications on safety assessment and remedial analyses of the radioactive waste dumps at ChNPP.

Soil-to-plant halogens transfer studies 2. Root uptake of radiochlorine by plants

“…During the experiment, data concerning air and soil temperature, rainfall, atmospheric pressure, air and soil humidity, intensity of solar irradiation, and wind direction and velocity were recorded by the meteorological stations located at the IRSN-IGS-UIAR-DAMRI experimental sites at a distance of 2 km (Bugai et al, 2002).…”

Soil-to-plant halogens transfer studies

“…During the experiment, data regarding the air and soil temperature, rain amount, atmospheric pressure, air and soil humidity, intensity of solar irradiation, and wind direction and velocity were recorded by the weather stations located at a distance of 2 km from the IRSN-IGS-UIAR-DAMRI experimental sites (Bugai et al, 2002).…”

Impact of Scots pine (Pinus sylvestris L.) plantings on long term 137Cs and 90Sr recycling from a waste burial site in the Chernobyl Red Forest

“…On the trench, the current extraction rate of 90 Sr by trees was 216 times more efficient than that of 137 Cs, and trees on the trench mobilized 5 times more 90 Sr than outside the trench. That large upward flux of 90 Sr through root uptake from the trench was at least of the same magnitude as 90 Sr downward migration losses from the trench as reported by Bugai et al (2002) and Dewiere et al (2004). Those authors determined that by 2001, 2-7% of the 90 Sr initial inventory in the trench was present in the underlying aquifer which corresponds to apparent annual rates of 90 Sr leaching from the waste material of 0.14-0.50%.…”

“…Sampling results of the waste material have been presented by Bugai et al (2002Bugai et al ( , 2005. They estimated the total inventory of initial radioactivity in trench no.22 in 2000 as 600 AE 240 GBq for 137 Cs and 290 AE 140 GBq for 90 Sr, with activity concentrations of the waste material varying from tens to thousands kBq kg À1 for both 137 Cs and 90 Sr.…”