Air concentrations of Chernobyl fallout radionuclides in the area Debrecen (Hungary)

Measurements of aerosol activity from the Chernobyl reactor accident are reported. The concentrations of 14 radionuclides were obtained by gamma spectrometry for the period 30 April–9 May, 1986. Gross beta measurements were also done through 11 August 1986 of which137Cs activity concentrations were derived.90Sr activity concentrations were also determined for selected aerosol samples using nondestructive procedure. The time course of contamination observed in Debrecen (Hungary) is discussed in terms of trajectory analysis. Isotopic ratios are also used to trace down routes of contaminated air. In addition, such ratios are also used to characterize the status of the damaged reactor at different times.