Time series for sea water and seaweed of 99Tc and 125Sb originating from releases at La Hague

Seasonal variation of technetium-99 in Fucus vesiculosus and its application as an oceanographic tracer

“…The measured concentration factor of 99 Tc ranges from 1.3 Â 10 5 to 2.4 Â 10 5 L/kg with a mean value and 2SD of (1.9 AE 0.5) Â 10 5 L/kg. This value agrees with the previously reported values of (1.75 AE 0.21) Â 10 5 L/kg (1SE of uncertainty) measured in F. vesiculosus collected from Klint (Denmark) (Masson et al, 1995), and (1.32 AE 0.46) Â 10 5 L/kg (2SD of uncertainty) in F. vesiculosus collected in Irish coast (Smith et al, 2001). The relatively constant concentration factors of 99 Tc in F. vesiculosus measured in this work (Figs.…”

“…For the monthly seaweed samples collected at Klint, Denmark in 1991e1992, the dominating source of 99 Tc is from La Hague reprocessing plant (Shi et al, 2012b). Although the monthly discharge of 99 Tc in the years of 1989e1990 is not available (the transit time is about 2 years from La Hague to Klint (Masson et al, 1995), according to the report by Patti 99 Tc from reprocessing plant do not significantly contribute to the seasonal variation of 99 Tc concentration in the seaweed from Kint during 1991e1992. Of course, as mentioned above, the increased discharges of 99 Tc increases the concentration of 99 Tc in seawater and accordingly in seaweed.…”

“…Because of the long halflife (T 1/2 ¼ 2.13 Â 10 5 y) as well as long residence time (technetium is assumed to occur in open seawater in the form of TcO À 4 ), 99 Tc has been used as an oceanographic tracer to track seawater movement and coastal pollution Dahlgaard, 1995). The transport of 99 Tc from western European reprocessing plants to distant sea areas, especially to Nordic seas has been a topic of extensive research in the last few decades Masson et al, 1995;Dahlgaard et al, 1995;Kershaw et al, 1999Kershaw et al, , 2004Brown et al, 2002;McCubbin et al, 2002;Karcher et al, 2004;Orre et al, 2007;Finegan et al, 2009).…”

Caractère conservatif de l'antimoine 125 dans les eaux marines soumises à l'influence des rejets de l'usine de retraitement des combustibles irradiés de La Hague

“…Il est apparu que l'utilisation de lZ5Sb ne permet plus actuellement une bonne évaluation de l'impact des rejets, en particulier depuis 1990. Cette situation montre qu'il convient de réactualiser les travaux (Boust et al, 1995 ;Germain et al, 1979 ;Masson et al, 1995 ;Salomon et al, 1991) par rapport aux rejets peu radioactifs de type (T + V). Les travaux cités en référence sont, en effet, relatifs aux années antérieures à 1990 où lZ5Sb pouvait être considéré comme représentatif des effluents A, déversés dans le milieu marin pendant la période de flux de marée le plus élevé, favorable à une dispersion rapide en direction de Manche-est.…”

Effects of complex hydrodynamic processes on the horizontal and vertical distribution of Tc-99 in the Irish Sea

“…Time series of radionuclide concentrations in sessile biota in coastal waters have been of great value in determining the extent and rate of spread of contamination by artificial radionuclides (Dahlgaard et al, 1997). However, it is difficult to account for all the observed temporal variability of Tc-99 in biota as a portion of radionuclides may be due to the seasonal effects of uptake (Masson et al, 1995). Historical data from seafood samples provided a comprehensive validation dataset due to the large sampling areas and long periods of collection.…”