Origin of artificial radionuclides in soil and sediment from North Wales. (January 2016)

• Record Type: Journal Article
• Authors: Al-Qasmi, Hamza; Law, Gareth T.W.; Fifield, L. Keith; Livens, Francis R.
• Is Part Of: Journal of environmental radioactivity. Volume 151:Part 1(2016:Jan.)
• Page Start: 244
• Page End: 249
• Publication Date: 2016-01
• Subjects: Radionuclide -- Afon Goch -- Irish Sea -- Sellafield; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2015.10.013
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: During the operations at the Sellafield nuclear fuel reprocessing complex, artificial radionuclides are discharged to the Irish Sea under authorisation, where they are dispersed. In this study, the southern distribution and transport of Sellafield derived radionuclides have been investigated. Both natural and artificial radionuclides have been studied in a soil core from the riverbank of the Afon Goch in Anglesey, North Wales. Particulate input is dominant for all artificial radionuclides (including the more soluble 137 Cs and 236 U) with an estimated lag time of about a decade. The preferential northward seawater movement in the NE Irish Sea limits solution input of 137 Cs and 236 U to the areas south of Sellafield. The relatively long lag time reflects both the water circulation pattern and distance between the study site in north Wales and the source point in Cumbria. Two redox active zones are observed in the top and the bottom of this core, although there is no evidence for any redistribution of Pu and natural uranium by these redox processes. However, 236 U, derived from irradiated uranium, showed variable distribution in the core. This could be a potential response to the geochemical conditions, showing that 236 U may be a promising tracer for the environmental processes and a signature of the Sellafield historical discharges of irradiated uranium. Highlights: Particulate input is the dominant mechanism for transport of Am, Pu, Cs and 236 U. Seawater circulation and distance control the lag time for radionuclide transport. Pu and natural uranium do not respond to the redox chemistry in the soil core. 236 U showed a potential response to the redox chemistry in the soil core. 236 U is a powerful marker for historical and geochemical signals.