composition of hot particles coming from Romania’s territory and the radionuclide
concentrations indicate that they belong to type “B” hot particles. The hot particles
identified in Romania by (Dovlete 1990a) were reported in the study of (Pollanen
et al. 1997) regarding the hot particles distributions across Europe.
Measurements of resuspended aerosols in the Chernobyl 30 km exclusion zone
have shown coarse fuel hot particles in the activity range 1–12 Bq
137
Cs per
particle.
Our measurements show a maximum of 6.5 Bq/hot particle for
137 Cs, 110 Bq/hot
particle for
144 Ce, 14.7 Bq/hot particle for
106 Ru and 3.3 Bq/hot particle for
125 Sb.
12.3.5 Post-Chernobyl Radioactivity of Danube and Surface
Waters
Water samples were collected at the NERSN stations, from the main rivers, main
lakes, Danube and Danube Delta. The Danube river water and sediment radioactivity was investigated in 1978 using high resolution gamma ray spectrometry by an
international expedition on-board a research vessel surveying the Danube from
Tulcea to Bratislava (Ghedeonov 1983).
Gross beta measurement and gamma spectrometric analysis were performed for
water samples from rivers from the following stations: Satu Mare, Oradea, Tg.
Mures, Cluj-Napoca, Timisoara, DrobetaTr.Severin, Craiova, Pitesti, Tulcea,
Galati, Buzau, Suceava, Bacau, Bechet, Sf.Gheorghe, Cernavoda, Baia-Mare,
Zimnicea, Ramnicu Valcea, Piatra Neamt, Arad, Focsani, Botosani, Giurgiu, Tg.
Jiu.
137 Cs annual mean spatially averaged specific activities of river water collected
at all the above-mentioned stations for the period 1987–1993, are presented in
Fig. 12.3.
Assuming a simple exponential dependence, the effective half-life for
137
Cs is
2.4 years. Fitting the mean specific activity (C(t)) of
137
Cs in water with a simple
power law, C(t), we obtain:
C t
ð Þ $ t
À0:91
If we select only the Danube river data series and simple exponential dependence, the effective half-life for
137 Cs is 2.1 years and for the power law fit we
obtain:
C t
ð Þ $ t
À0:89
Besides the water samples, sediment samples were taken along the Danube
river and in the Danube Delta twice yearly (June-July and October-December).
Besides
40 K and gamma emitters from natural radioactivity series, artificial
radionuclides of Chernobyl origin such as
137 Cs,
134 Cs,
106 Ru,
144 Ce,
125 Sb
were identified (Sonoc et al. 1989a). The specific activity of
137 Cs in the Danube
214
C. Dovlete et al.
concentrations indicate that they belong to type “B” hot particles. The hot particles
identified in Romania by (Dovlete 1990a) were reported in the study of (Pollanen
et al. 1997) regarding the hot particles distributions across Europe.
Measurements of resuspended aerosols in the Chernobyl 30 km exclusion zone
have shown coarse fuel hot particles in the activity range 1–12 Bq
137
Cs per
particle.
Our measurements show a maximum of 6.5 Bq/hot particle for
137 Cs, 110 Bq/hot
particle for
144 Ce, 14.7 Bq/hot particle for
106 Ru and 3.3 Bq/hot particle for
125 Sb.
12.3.5 Post-Chernobyl Radioactivity of Danube and Surface
Waters
Water samples were collected at the NERSN stations, from the main rivers, main
lakes, Danube and Danube Delta. The Danube river water and sediment radioactivity was investigated in 1978 using high resolution gamma ray spectrometry by an
international expedition on-board a research vessel surveying the Danube from
Tulcea to Bratislava (Ghedeonov 1983).
Gross beta measurement and gamma spectrometric analysis were performed for
water samples from rivers from the following stations: Satu Mare, Oradea, Tg.
Mures, Cluj-Napoca, Timisoara, DrobetaTr.Severin, Craiova, Pitesti, Tulcea,
Galati, Buzau, Suceava, Bacau, Bechet, Sf.Gheorghe, Cernavoda, Baia-Mare,
Zimnicea, Ramnicu Valcea, Piatra Neamt, Arad, Focsani, Botosani, Giurgiu, Tg.
Jiu.
137 Cs annual mean spatially averaged specific activities of river water collected
at all the above-mentioned stations for the period 1987–1993, are presented in
Fig. 12.3.
Assuming a simple exponential dependence, the effective half-life for
137
Cs is
2.4 years. Fitting the mean specific activity (C(t)) of
137
Cs in water with a simple
power law, C(t), we obtain:
C t
ð Þ $ t
À0:91
If we select only the Danube river data series and simple exponential dependence, the effective half-life for
137 Cs is 2.1 years and for the power law fit we
obtain:
C t
ð Þ $ t
À0:89
Besides the water samples, sediment samples were taken along the Danube
river and in the Danube Delta twice yearly (June-July and October-December).
Besides
40 K and gamma emitters from natural radioactivity series, artificial
radionuclides of Chernobyl origin such as
137 Cs,
134 Cs,
106 Ru,
144 Ce,
125 Sb
were identified (Sonoc et al. 1989a). The specific activity of
137 Cs in the Danube
214
C. Dovlete et al.