Mobility of Chernobyl-derived 137Cs in a peatbog system within the catchment of the Pripyat River, Belarus

Abstract

The behaviour of Chernobyl-derived 137Cs in a hydrologically isolated bog system in the catchment of the Pripyat River, Belarus was investigated. Measurements were made of 137Cs activities in the solids and pore waters of the bog soils, as well as the variability in activity in water draining from the bog. It was found that the radiocaesium activity of the pore water, and hence the measured distribution coefficient, Kd, was dependent upon the pressure at which the water was removed from the soil. Measured values of Kd were of the order 10(2) l/kg at an extraction pressure of 0.8 MPa, approximately one order of magnitude lower than those measured in a similar system, Devoke Water, in the UK [1]. Results of comparative measurements suggested that this was a result of the different pore water extraction techniques used. The vertical migration of radiocaesium was modelled using a solution of the advection-diffusion equation. Using a mass balance approach, it was estimated that 137Cs was removed from the system at a rate of 0.3% of the catchment inventory per year, approximately 8 years after the Chernobyl accident. It was shown that both vertical migration and removal of 137Cs is best modelled using a Kd based on a measurement of pore water held at low pressure in the soil, approximately 10(3) l/kg. 137Cs activities in soil pore waters and in drainage waters were very strongly related to the aqueous potassium concentration, and both showed concentration minima in drainage water during the spring. It was shown that runoff coefficients of radiocaesium from peat bogs 8 years after the Chernobyl accident were approximately one order of magnitude greater than those from unsaturated soils of higher mineral content.

Radioisotope contaminations from releases of the Tomsk–Seversk nuclear facility (Siberia, Russia)

“…larger than 10 Bq kg À1 ) can be observed below 30 cm, which is accounted by downward diffusion of this element in the peat. MacKenzie et al (1997) and Kudelsky et al (1996) reported the high mobility of this element in peats from Scotland and from the catchment of the Pripyat River (Belarus). The total accumulation of 137 Cs in the peat profile reaches 11,246 Bq m À2 .…”

Watershed wash-off of atmospherically deposited radionuclides: review of the fluxes and their evolution with time

“…Nuclide Range Unit n Sources Liquid wash-off 137 Cs 6.7 Â 10 À5 e0.02 /yr 62 Beasley and Jennings (1984), Bilyi et al (1997), Carlsson (1978), Kudelsky et al (1996), Linsley et al (1982), Rogowski and Tamura (1970) and Spezzano et al (1993) Liquid wash-off 90 Sr 6.7 Â 10 À4 e0.05 /yr 28 Helton et al (1985), Kamada et al (1974), Linsley et al (1982), Miyake and Tsubota (1963), Monte (1995), Pisarev et al (1972) and Yamagata et al (1963) Solid wash-off 241 Am 1 Â 10 À4 e2 Â 10 À4 /yr 2 Beasley and Jennings (1984) and Solid wash-off 7 Be 0.02 /yr 1 Joshi and Shukla (1991) Solid wash-off 137 Cs 8.9 Â 10 À5 e0.12 /yr 11 Beasley and Jennings (1984), Bonnett (1990), Dominik et al (1987), , Khanbilvardi et al (1999), Rogowski and Tamura (1970), Smith et al (1987) and Walling et al (1986) Solid wash-off 210 Pb 3.3 Â 10 À4 e7.14 Â 10 À4 /yr 2 Dominik et al (1987) and Joshi and Shukla (1991) Solid wash-off Pu 2 Â 10 À5 e6 Â 10 À3 /yr 36 Beasley and Jennings (1984), Bonnett (1990), Foster and Hakonson (1984), and Smith et al (1987) Total wash-off 137 Cs 3.75 Â 10 À5 e0.01 /yr 18 Beasley and Jennings (1984), Bonnett (1990), Ettenhuber et al (1990), Kudelsky et al (1997), Linsalata et al (1985), Matsunaga (2000), Queirazza et al (1987), Smith et al (2000), Spezzano et al (1994) and Yamagata et al (1963) …”

Distribution and mobility of137Cs,90Sr,239,240Pu and241Am in solid phase-interstitial soil solution system

“…The mobility of ,37 Cs essentially depends on the concentration of K + and NH/ in water phase [3,4]. These cations compete with 137 Cs for FES and increase caesium transfer from solid phase into interstitial soil solution and NFL/ is more selective to FES than K + .…”