title: Plutonium Isotopes (239-241Pu) Dissolved in Pacific Ocean Waters Detected by Accelerator Mass Spectrometry: No Effects of the Fukushima Accident Observed.
abstract: The concentration of plutonium (Pu) and the isotopic ratios of240Pu to239Pu and241Pu to239Pu were determined by accelerator mass spectrometry (AMS) in Pacific Ocean water samples (20 L each) collected in late 2012. The isotopic Pu ratios are important indicators of different contamination sources and were used to identify a possible release of Pu into the ocean by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. In particular,241Pu is a well-suited indicator for a recent entry of Pu because241Pu from fallout of nuclear weapon testings has already significantly decayed. A total of 10 ocean water samples were prepared at the Radiochemie München of the TUM and analyzed at the Vienna Environmental Research Laboratory (VERA). Several samples showed a slightly elevated240Pu/239Pu ratio of up to 0.22 ± 0.02 compared to global fallout (240Pu/239Pu = 0.180 ± 0.007), whereas all measured241Pu-to-239Pu ratios were consistent with nuclear weapon fallout (241Pu/239Pu < 2.4 × 10-3), which means that no impact from the Fukushima accident was detected. From the average241Pu-to-239Pu ratio of 8-2+3×10-4at a sampling station located at a distance of 39.6 km to FDNPP, the 1-σ upper limit for the FDNPP contribution to the239Pu inventory in the water column was estimated to be 0.2%. Pu, with the signature of weapon-grade Pu was found in a single sample collected around 770 km off the west coast of the United States.
authors.affiliation: Physics Department, Technical University of Munich , James-Franck-Strasse 1, 85748 Garching, Germany.
authors.forename: Karin
authors.identifier: 0000-0001-5083-1986
authors.initials: K
authors.lastname: Hain
authors.affiliation: Physics Department, Technical University of Munich , James-Franck-Strasse 1, 85748 Garching, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Faestermann
authors.affiliation: Physics Department, Technical University of Munich , James-Franck-Strasse 1, 85748 Garching, Germany.
authors.forename: Leticia
authors.initials: L
authors.lastname: Fimiani
authors.affiliation: Faculty of Physics, Isotope Research and Nuclear Physics, University of Vienna , Währinger Strasse 17, 1090 Vienna, Austria.
authors.forename: Robin
authors.initials: R
authors.lastname: Golser
authors.affiliation: Physics Department, Technical University of Munich , James-Franck-Strasse 1, 85748 Garching, Germany.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Gómez-Guzmán
authors.affiliation: Physics Department, Technical University of Munich , James-Franck-Strasse 1, 85748 Garching, Germany.
authors.forename: Gunther
authors.initials: G
authors.lastname: Korschinek
authors.affiliation: Radiochemie München, Technische Universität München , Walther-Meißner-Strasse 3, 85748 Garching, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Kortmann
authors.affiliation: Radiochemie München, Technische Universität München , Walther-Meißner-Strasse 3, 85748 Garching, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Lierse von Gostomski
authors.affiliation: Physics Department, Technical University of Munich , James-Franck-Strasse 1, 85748 Garching, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Ludwig
authors.affiliation: Faculty of Physics, Isotope Research and Nuclear Physics, University of Vienna , Währinger Strasse 17, 1090 Vienna, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Steier
authors.affiliation: Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University , 66-1 Hon-cho, Hirosaki, Aomori, 036 8564 Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tazoe
authors.affiliation: Department of Radiation Chemistry, Institute of Radiation Emergency Medicine, Hirosaki University , 66-1 Hon-cho, Hirosaki, Aomori, 036 8564 Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamada
mesh_terms: D062406:Fukushima Nuclear Accident; D007554:Isotopes; D013058:Mass Spectrometry; D010140:Pacific Ocean; D011005:Plutonium; D011834:Radiation Monitoring; D011847:Radioactive Fallout; D014875:Water Pollutants, Radioactive
chemical_list: D007554:Isotopes; D011847:Radioactive Fallout; D014875:Water Pollutants, Radioactive; D011005:Plutonium