Variability in the supply, distribution and transport of the transient tracer 99Tc in the NE Atlantic

Assessment of Tc-99 monitoring within the western Irish Sea using a numerical model

“…The main sources of this radionuclide in the Irish Sea waters are discharges from the British Nuclear Fuels (BNF) reprocessing plant at Sellafield (Cumbria, UK). Radionuclides derived form Sellafield are now also known to be a major source to the shelf seas of north-western Europe (Orre et al, 2007) and north east Atlantic (Kershaw, 2004). Controlled discharges into the north-eastern Irish Sea began in 1952 and since then have been the subject of national and international controversy.…”

Diagnosing ocean tracer transport from Sellafield and Dounreay by equivalent diffusion and age

“…After relatively low release rates of 99 Tc during the 1980s and the early 1990s, a rapid increase from Sellafield started from April 1994. This "pulse" of 99 Tc was observed in the Barents Sea region several years later (e.g., Kershaw et al, 2004). In Orre et al (2007) it was demonstrated that the model reproduced the observed values on the north coast of Norway fairly accurately.…”

“…This is to supplement the many studies of 99 Tc in this period (e.g., Kershaw et al, 2004;Karcher et al, 2004;Orre et al, 2007). We consider the following idealized release rates from Sellafield and Dounreay:…”

“…There is also a branch being transported southwards along the east Greenland coast. A more thorough description of tracer transport from Sellafield and possible forcing mechanisms are given in Kershaw et al (2004) and Orre et al (2007).…”

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

“…There was also a substantial amount of work undertaken on Tc-99 dispersion properties in the North-East Atlantic (e.g. Kershaw et al, 1999Kershaw et al, , 2004 and in the North and Norwegian Sea (e.g. Orre et al, 2007).…”