First dataset of 236U and 233U around the Greenland coast: A 5-year snapshot (2012–2016). (October 2020)

• Record Type: Journal Article
• Authors: Qiao, Jixin; Hain, Karin; Steier, Peter
• Is Part Of: Chemosphere. Volume 257(2020)
• Publication Date: 2020-10
• Subjects: 233U -- 236U -- Greenland coast -- Surface seawater -- 2012–2016; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.127185
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: We report the first combined dataset of 236 U and 233 U in the Greenland marine environment during the period of 2012–2016. Results are discussed in terms of time evolution and spatial distribution of 236 U concentration, and atomic ratios of 236 U/ 238 U and 233 U/ 236 U. 236 U concentrations along the Greenland coast are distributed within a relatively narrow range of (0.7–12.9) × 10 7 atom/L, corresponding to 236 U/ 238 U atomic ratios of (1.1–15.5) × 10 −9 . The 233 U/ 236 U atomic ratios obtained vary from 0.12 × 10 −2 to 1.16 × 10 −2, with the majority distributed in the range of (0.2–0.7) × 10 −2 . We applied 233 U/ 236 U and 236 U/ 238 U atomic ratios in a binary mixing model to identify possible 236 U source terms. The results indicate that anthropogenic 236 U and 233 U in Greenland surface seawater originated from the direct global fallout (DGF) and the Sellafield and La Hague reprocessing plants (RP) is diluted by a third endmember, mostly likely natural ocean water (NOW), containing marginal 236 U and 233 U. A preliminary estimation of the source terms of 236 U using 233 U/ 236 U atomic ratios indicate that, for both eastern and western Greenland seawater, contributions from global fallout (GF) constitute about 30% of 236 U. The dominating source for 236 U, i.e. 70 %, is associated to reactor 236 U including discharges from RP and local reactor input in the Arctic Ocean. Graphical abstract: Image 1 Highlights: First results of 236 U and 233 U in the Greenland marine environment. 236 U concentration in Greenland seawater has a narrow distribution range. No significant difference in 236 U level between east and west Greenland coast. Binary mixing using 233 U/ 236 U and 236 U/ 238 U to interpret 236 U source terms. 236 U source contribution is calculated based on 233 U/ 236 U atomic ratios.