Dynamics, deterministic nature and correlations of outdoor (222)Rn and (220)Rn progeny concentrations measured at Bacău, Romania.

The long-term variation, nature and correlations of outdoor (222)Rn and (220)Rn progeny concentrations measured during the period 1994-2009 were investigated. The time series of data were obtained within the framework of the monitoring program performed by the Environmental Radioactivity Monitoring Station (ERMS) Bacău, a component part of the National Environmental Radioactivity Survey Network (NERSN), coordinated by National Environmental Protection Agency (NEPA). The measuring method is based on the total beta measurements of atmospheric aerosol filters, using a low background total beta counter and ((90)Sr/Y) reference standard.

Statistical characteristics of radionuclide concentration field around a nuclear power plant.

A Markov chain model with two states is used for investigating the space and time structure of the concentration field around an elevated continuous source. The concentration field is computed with a time-dependent Gaussian puff dispersion model run with observed meteorological data as input. Spatial distributions of transition probability, Besson persistence coefficient and order of Markov chain are presented for tritium routinely released from a nuclear power plant located about 100 miles east of Bucharest, Romania.

Time dependence of the 137Cs resuspension factor on the Romanian territory after the Chernobyl accident.

On the basis of the radioactivity levels in aerosol and atmospherical deposition samples due to the Chernobyl accident, the resuspension factor of 137Cs as a four-parameter function has been inferred. The standard procedure to derive the dependence of resuspension on time assumes that the initial deposit is instantaneous. A simple method assuming a constant deposition rate over a fixed period has been proposed.