Accumulation of Sellafield-derived radiocarbon ( 14 C) in Irish Sea and West of Scotland intertidal shells and sediments

Abstract

The nuclear energy industry produces radioactive waste at various stages of the fuel cycle. In the United Kingdom, spent fuel is reprocessed at the Sellafield facility in Cumbria on the North West coast of England. Waste generated at the site comprises a wide range of radionuclides including radiocarbon ((14)C) which is disposed of in various forms including highly soluble inorganic carbon within the low level liquid radioactive effluent, via pipelines into the Irish Sea. This (14)C is rapidly incorporated into the dissolved inorganic carbon (DIC) reservoir and marine calcifying organisms, e.g. molluscs, readily utilise DIC for shell formation. This study investigated a number of sites located in Irish Sea and West of Scotland intertidal zones. Results indicate (14)C enrichment above ambient background levels in shell material at least as far as Port Appin, 265 km north of Sellafield. Of the commonly found species (blue mussel (Mytilus edulis), common cockle (Cerastoderma edule) and common periwinkle (Littorina littorea)), mussels were found to be the most highly enriched in (14)C due to the surface environment they inhabit and their feeding behaviour. Whole mussel shell activities appear to have been decreasing in response to reduced discharge activities since the early 2000s but in contrast, there is evidence of continuing enrichment of the carbonate sediment component due to in-situ shell erosion, as well as indications of particle transport of fine (14)C-enriched material close to Sellafield.

Novel Method of Extraction for Radiocarbon Measurements of Atmospheric Carbon dioxide

“…There are also anthropogenic sources of 14 C. A large amount of 14 C was produced and released as a result of nuclear weapons testing in the 1950s and 60s and subsequently distributed via the carbon cycle, doubling the atmospheric inventory of 14 CO 2 (Nydal and Lovseth 1983;Levin et al 1985;Manning et al 1990). The nuclear power industry also releases 14 CO 2 , which offsets the depletion caused by fossil fuel combustion (Vokal and Kobal 1997;McNamara et al 1998;Fontugne et al 2004;Yim and Caron 2006;Magnusson 2007;Molnar et al 2007;Dias et al 2009;Graven and Gruber 2011;Aulagnier et al 2012;Svetlik et al 2012;Wang et al 2012Wang et al , 2013Wang et al , 2014Vogel et al 2013;Metcalfe and Mills 2015;Tierney et al 2016).…”