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Payne TE, Harrison JJ, Child DP, Hankin S, Hotchkis MAC, Hughes CE, Johansen MP, Thiruvoth S, Wilsher KL. Accelerator mass spectrometry measurements of 233U in groundwater, soil and vegetation at a legacy radioactive waste site. Chemosphere 2024; 358:141761. [PMID: 38531499 DOI: 10.1016/j.chemosphere.2024.141761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/27/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
Low-level radioactive wastes were disposed at the Little Forest Legacy Site (LFLS) near Sydney, Australia between 1960 and 1968. According to the disposal records, 233U contributes a significant portion of the inventory of actinide activity buried in the LFLS trenches. Although the presence of 233U in environmental samples from LFLS has been previously inferred from alpha-spectrometry measurements, it has been difficult to quantify because the 233U and 234U α-peaks are superimposed. Therefore, the amounts of 233U in groundwaters, soils and vegetation from the vicinity of the LFLS were measured using accelerator mass spectrometry (AMS). The AMS results show the presence of 233U in numerous environmental samples, particularly those obtained within, and in the immediate vicinity of, the trenched area. There is evidence for dispersion of 233U in groundwater (possibly mobilised by co-disposed organic liquids), and the data also suggest other sources of 233U contamination in addition to the trench wastes. These may include leakages and spills from waste drums as well as waste burnings, which also occurred at the site. The AMS results confirm the historic information regarding disposal of 233U in the LFLS trenches. The AMS technique has been valuable to ascertain the distribution and environmental behaviour of 233U at the LFLS and the results demonstrate the applicability of AMS for evaluating contamination of 233U at other radioactive waste sites.
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Affiliation(s)
- Timothy E Payne
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - Jennifer J Harrison
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - David P Child
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Stuart Hankin
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Michael A C Hotchkis
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Catherine E Hughes
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Mathew P Johansen
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Sangeeth Thiruvoth
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Kerry L Wilsher
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
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2
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Johansen MP, Child DP, Collins R, Cook M, Davis J, Hotchkis MAC, Howard DL, Howell N, Ikeda-Ohno A, Young E. Radioactive particles from a range of past nuclear events: Challenges posed by highly varied structure and composition. Sci Total Environ 2022; 842:156755. [PMID: 35718169 DOI: 10.1016/j.scitotenv.2022.156755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia.
| | - David P Child
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | | | - Megan Cook
- International Atomic Energy Agency (IAEA), Environmental Laboratories, Monaco
| | - Joel Davis
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Michael A C Hotchkis
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Daryl L Howard
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Nicholas Howell
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Atsushi Ikeda-Ohno
- Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195, Japan
| | - Emma Young
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
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3
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Harrison JJ, Saunders KM, Child DP, Hotchkis MAC. A record of fallout 239Pu and 240Pu at World Heritage Bathurst Harbour, Tasmania, Australia. J Environ Radioact 2021; 237:106679. [PMID: 34118615 DOI: 10.1016/j.jenvrad.2021.106679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 05/21/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
This study presents the first measurements of anthropogenic plutonium (239Pu and 240Pu) concentrations and atom ratios (240Pu/239Pu) for Tasmania, in sediment collected from Bathurst Harbour, in the Tasmanian Wilderness World Heritage Area, Australia. The weighted mean 240Pu/239Pu atom ratio measured at this site was 0.172 ± 0.007 which is consistent with published data from mainland Australia and global and Southern Hemisphere averages. The 240Pu/239Pu atom ratios ranged between 0.11 and 0.21 with the earliest recorded 240Pu/239Pu atom ratios being the lowest, suggesting an influence of low atom ratio fallout from nuclear testing in Australia. Post-moratorium fallout 240Pu/239Pu atom ratios were consistent with other records. Lead-210 (210Pb) sediment chronologies indicate sediment accumulation rates have increased since the early part of the 19th century at this location.
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Affiliation(s)
- Jennifer J Harrison
- ANSTO, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, New South Wales, 2234, Australia.
| | - Krystyna M Saunders
- ANSTO, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, New South Wales, 2234, Australia.
| | - David P Child
- ANSTO, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, New South Wales, 2234, Australia.
| | - Michael A C Hotchkis
- ANSTO, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, New South Wales, 2234, Australia.
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4
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Wallner A, Froehlich MB, Hotchkis MAC, Kinoshita N, Paul M, Martschini M, Pavetich S, Tims SG, Kivel N, Schumann D, Honda M, Matsuzaki H, Yamagata T. 60Fe and 244Pu deposited on Earth constrain the r-process yields of recent nearby supernovae. Science 2021; 372:742-745. [PMID: 33986180 DOI: 10.1126/science.aax3972] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 04/12/2021] [Indexed: 11/02/2022]
Abstract
Half of the chemical elements heavier than iron are produced by the rapid neutron capture process (r-process). The sites and yields of this process are disputed, with candidates including some types of supernovae (SNe) and mergers of neutron stars. We search for two isotopic signatures in a sample of Pacific Ocean crust-iron-60 (60Fe) (half-life, 2.6 million years), which is predominantly produced in massive stars and ejected in supernova explosions, and plutonium-244 (244Pu) (half-life, 80.6 million years), which is produced solely in r-process events. We detect two distinct influxes of 60Fe to Earth in the last 10 million years and accompanying lower quantities of 244Pu. The 244Pu/60Fe influx ratios are similar for both events. The 244Pu influx is lower than expected if SNe dominate r-process nucleosynthesis, which implies some contribution from other sources.
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Affiliation(s)
- A Wallner
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia. .,Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, 01328 Dresden, Germany
| | - M B Froehlich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M A C Hotchkis
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - N Kinoshita
- Institute of Technology, Shimizu Corporation, Tokyo 135-8530, Japan
| | - M Paul
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - M Martschini
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S Pavetich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S G Tims
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - N Kivel
- Laboratory of Radiochemistry, Department for Nuclear Energy and Safety, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - D Schumann
- Laboratory of Radiochemistry, Department for Nuclear Energy and Safety, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - M Honda
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Ibaraki 305-8577, Japan
| | - H Matsuzaki
- Micro Analysis Laboratory, Tandem Accelerator, The University Museum, The University of Tokyo, Tokyo 113-0032, Japan
| | - T Yamagata
- Micro Analysis Laboratory, Tandem Accelerator, The University Museum, The University of Tokyo, Tokyo 113-0032, Japan
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Johansen MP, Anderson D, Child D, Hotchkis MAC, Tsukada H, Okuda K, Hinton TG. Differentiating Fukushima and Nagasaki plutonium from global fallout using 241Pu/ 239Pu atom ratios: Pu vs. Cs uptake and dose to biota. Sci Total Environ 2021; 754:141890. [PMID: 32916482 DOI: 10.1016/j.scitotenv.2020.141890] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 06/11/2023]
Abstract
Plutonium (Pu) has been released in Japan by two very different types of nuclear events - the 2011 Fukushima accident and the 1945 detonation of a Pu-core weapon at Nagasaki. Here we report on the use of Accelerator Mass Spectrometry (AMS) methods to distinguish the FDNPP-accident and Nagasaki-detonation Pu from worldwide fallout in soils and biota. The FDNPP-Pu was distinct in local environmental samples through the use of highly sensitive 241Pu/239Pu atom ratios. In contrast, other typically-used Pu measures (240Pu/239Pu atom ratios, activity concentrations) did not distinguish the FDNPP Pu from background in most 2016 environmental samples. Results indicate the accident contributed new Pu of ~0.4%-2% in the 0-5 cm soils, ~0.3%-3% in earthworms, and ~1%-10% in wild boar near the FDNPP. The uptake of Pu in the boar appears to be relatively uninfluenced by the glassy particle forms of fallout near the FDNPP, whereas the 134,137Cs uptake appears to be highly influenced. Near Nagasaki, the lasting legacy of Pu is greater with high percentages of Pu sourced from the 1945 detonation (~93% soils, ~88% earthworm, ~96% boar). The Pu at Nagasaki contrasts with that from the FDNPP in having proportionately higher 239Pu and was distinguished by both 240Pu/239Pu and 241Pu/239Pu atom ratios. However, compared with the contamination near the Chernobyl accident site, the Pu amounts at all study sites in Japan are orders of magnitude lower. The dose rates from Pu to organisms in the FDNPP and Nagasaki areas, as well as to human consumers of wild boar meat, have been only slightly elevated above background. Our data demonstrate the greater sensitivity of 241Pu/239Pu atom ratios in tracing Pu from nuclear releases and suggest that the Nagasaki-detonation Pu will be distinguishable in the environment for much longer than the FDNPP-accident Pu.
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Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation, Sydney, Australia.
| | - Donovan Anderson
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan; Symbiotic Systems Science and Technology, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan
| | - David Child
- Australian Nuclear Science and Technology Organisation, Sydney, Australia
| | | | - Hirofumi Tsukada
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan
| | - Kei Okuda
- Faculty of Human Environmental Studies, Hiroshima Shudo University, 731-3195, Hiroshima Prefecture, Asaminami-ku, Ozuka-higashi, Japan
| | - Thomas G Hinton
- Institute of Environmental Radioactivity, Fukushima University, 960-1248, Fukushima Prefecture, Fukushima, Kanayagawa, Japan; CERAD CoE, Norwegian University of Life sciences, Faculty for Environmental Sciences and Nature Research Management, Aas, Norway
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6
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Wallner A, Feige J, Fifield LK, Froehlich MB, Golser R, Hotchkis MAC, Koll D, Leckenby G, Martschini M, Merchel S, Panjkov S, Pavetich S, Rugel G, Tims SG. 60Fe deposition during the late Pleistocene and the Holocene echoes past supernova activity. Proc Natl Acad Sci U S A 2020; 117:21873-21879. [PMID: 32839339 PMCID: PMC7486756 DOI: 10.1073/pnas.1916769117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nuclides synthesized in massive stars are ejected into space via stellar winds and supernova explosions. The solar system (SS) moves through the interstellar medium and collects these nucleosynthesis products. One such product is 60Fe, a radionuclide with a half-life of 2.6 My that is predominantly produced in massive stars and ejected in supernova explosions. Extraterrestrial 60Fe has been found on Earth, suggesting close-by supernova explosions ∼2 to 3 and ∼6 Ma. Here, we report on the detection of a continuous interstellar 60Fe influx on Earth over the past ∼33,000 y. This time period coincides with passage of our SS through such interstellar clouds, which have a significantly larger particle density compared to the local average interstellar medium embedding our SS for the past few million years. The interstellar 60Fe was extracted from five deep-sea sediment samples and accelerator mass spectrometry was used for single-atom counting. The low number of 19 detected atoms indicates a continued but low influx of interstellar 60Fe. The measured 60Fe time profile over the 33 ky, obtained with a time resolution of about ±9 ky, does not seem to reflect any large changes in the interstellar particle density during Earth's passage through local interstellar clouds, which could be expected if the local cloud represented an isolated remnant of the most recent supernova ejecta that traversed the Earth ∼2 to 3 Ma. The identified 60Fe influx may signal a late echo of some million-year-old supernovae with the 60Fe-bearing dust particles still permeating the interstellar medium.
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Affiliation(s)
- A Wallner
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia;
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - J Feige
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
- Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, 10623 Berlin, Germany
| | - L K Fifield
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M B Froehlich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - R Golser
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
| | - M A C Hotchkis
- Centre for Accelerator Science, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - D Koll
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - G Leckenby
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - M Martschini
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
- Isotope Physics, Faculty of Physics, Vienna Environmental Research Accelerator Laboratory, University of Vienna, 1090 Vienna, Austria
| | - S Merchel
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - S Panjkov
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - S Pavetich
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
| | - G Rugel
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - S G Tims
- Department of Nuclear Physics, Research School of Physics, Australian National University, Canberra, ACT 2601, Australia
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7
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Johansen MP, Child DP, Hotchkis MAC, Johansen A, Thiruvoth S, Whiting SD. Radionuclides in sea turtles at the Montebello Islands former nuclear test sites: Current and historical dose rates for adults and embryos. Mar Pollut Bull 2020; 158:111390. [PMID: 32753176 DOI: 10.1016/j.marpolbul.2020.111390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
Radionuclides from 1950s weapons testing at the Montebello Islands, Western Australia, may impact sea turtle embryos incubating within eggs laid in contaminated sands or be taken up into adult body tissues where they can contribute to radiation dose over a turtles' 60+ year lifespan. We measured plutonium in all local samples including turtle skin, bones, hatchlings, eggshells, sea sediments, diet items and beach sands. The amount of Pu in developing embryos/hatchling samples was orders of magnitude lower than that in the surrounding sands. These contaminated sands caused most dose to eggs (external dose from 137Cs, 152Eu), while most of the dose to adults was from internalised radionuclides (98%). While current dose rates are relatively low, local dose rates were high for about ten years following the 1950s detonations and may have resulted in lethality or health impacts to a generation of turtles that likely carry biomarkers today.
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Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation, Sydney, Australia.
| | - David P Child
- Australian Nuclear Science and Technology Organisation, Sydney, Australia
| | | | - Andrea Johansen
- Australian Nuclear Science and Technology Organisation, Sydney, Australia
| | - Sangeeth Thiruvoth
- Australian Nuclear Science and Technology Organisation, Sydney, Australia
| | - Scott D Whiting
- Western Australia Department of Biodiversity Conservation and Attractions, Kensington, Australia
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Johansen MP, Child DP, Cresswell T, Harrison JJ, Hotchkis MAC, Howell NR, Johansen A, Sdraulig S, Thiruvoth S, Young E, Whiting SD. Plutonium and other radionuclides persist across marine-to-terrestrial ecotopes in the Montebello Islands sixty years after nuclear tests. Sci Total Environ 2019; 691:572-583. [PMID: 31325857 DOI: 10.1016/j.scitotenv.2019.06.531] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/29/2019] [Accepted: 06/30/2019] [Indexed: 06/10/2023]
Abstract
Since the 1956 completion of nuclear testing at the Montebello Islands, Western Australia, this remote uninhabited island group has been relatively undisturbed (no major remediations) and currently functions as high-value marine and terrestrial habitat within the Montebello/Barrow Islands Marine Conservation Reserves. The former weapons testing sites, therefore, provide a unique opportunity for assessing the fate and behaviour of Anthropocene radionuclides subjected to natural processes across a range of shallow-marine to island-terrestrial ecological units (ecotopes). We collected soil, sediment and biota samples and analysed their radionuclide content using gamma and alpha spectrometry, photostimulated luminescence autoradiography and accelerator mass spectrometry. We found the activity levels of the fission and neutron-activation products have decreased by ~hundred-fold near the ground zero locations. However, Pu concentrations remain elevated, some of which are high relative to most other Australian and international sites (up to 25,050 Bq kg-1 of 239+240+241Pu). Across ecotopes, Pu ranked from highest to lowest in the following order: island soils > dunes > foredunes > marine sediments > and beach intertidal zone. Low values of Pu and other radionuclides were detected in all local wildlife tested including endangered species. Activity concentrations ranked (highest to lowest) terrestrial arthropods > terrestrial mammal and reptile bones > algae > oyster flesh > whole crab > sea turtle bone > stingray and teleost fish livers > sea cucumber flesh > sea turtle skin > teleost fish muscle. The three detonations (one from within a ship and two from 30 m towers) resulted in differing contaminant forms, with the ship detonation producing the highest activity concentrations and finer more inhalable particulate forms. The three sites are distinct in their 240/239Pu and 241/239Pu atom ratios, including the Pu transported by natural process or within migratory living organisms.
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Affiliation(s)
| | | | | | | | | | | | | | - S Sdraulig
- Australian Radiation Protection and Nuclear Safety Agency, Yallambie, Australia
| | | | | | - S D Whiting
- Department of Biodiversity, Conservation and Attractions, Kensington, WA, Australia
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Smith BS, Child DP, Fierro D, Harrison JJ, Heijnis H, Hotchkis MAC, Johansen MP, Marx S, Payne TE, Zawadzki A. Measurement of fallout radionuclides, (239)(,240)Pu and (137)Cs, in soil and creek sediment: Sydney Basin, Australia. J Environ Radioact 2016; 151 Pt 3:579-586. [PMID: 26344369 DOI: 10.1016/j.jenvrad.2015.06.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 06/12/2015] [Accepted: 06/19/2015] [Indexed: 06/05/2023]
Abstract
Soil and sediment samples from the Sydney basin were measured to ascertain fallout radionuclide activity concentrations and atom ratios. Caesium-137 ((137)Cs) was measured using gamma spectroscopy, and plutonium isotopes ((239)Pu and (240)Pu) were quantified using accelerator mass spectrometry (AMS). Fallout radionuclide activity concentrations were variable ranging from 0.6 to 26.1 Bq/kg for (137)Cs and 0.02-0.52 Bq/kg for (239+240)Pu. Radionuclides in creek sediment samples were an order of magnitude lower than in soils. (137)Cs and (239+240)Pu activity concentration in soils were well correlated (r(2) = 0.80) although some deviation was observed in samples collected at higher elevations. Soil ratios of (137)Cs/(239+240)Pu (decay corrected to 1/1/2014) ranged from 11.5 to 52.1 (average = 37.0 ± 12.4) and showed more variability than previous studies. (240)Pu/(239)Pu atom ratios ranged from 0.117 to 0.165 with an average of 0.146 (±0.013) and an error weighted mean of 0.138 (±0.001). These ratios are lower than a previously reported ratio for Sydney, and lower than the global average. However, these ratios are similar to those reported for other sites within Australia that are located away from former weapons testing sites and indicate that atom ratio measurements from other parts of the world are unlikely to be applicable to the Australian context.
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Affiliation(s)
- B S Smith
- GeoQuEST, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - D P Child
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - D Fierro
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - J J Harrison
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - H Heijnis
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - M A C Hotchkis
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - M P Johansen
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - S Marx
- GeoQuEST, School of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - T E Payne
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
| | - A Zawadzki
- Institute for Environmental Research, Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, 2234, Australia
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10
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Johansen MP, Child DP, Caffrey EA, Davis E, Harrison JJ, Hotchkis MAC, Payne TE, Ikeda-Ohno A, Thiruvoth S, Twining JR, Beresford NA. Accumulation of plutonium in mammalian wildlife tissues following dispersal by accidental-release tests. J Environ Radioact 2016; 151 Pt 2:387-394. [PMID: 25910926 DOI: 10.1016/j.jenvrad.2015.03.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 03/20/2015] [Accepted: 03/26/2015] [Indexed: 06/04/2023]
Abstract
We examined the distribution of plutonium (Pu) in the tissues of mammalian wildlife inhabiting the relatively undisturbed, semi-arid former Taranaki weapons test site, Maralinga, Australia. The accumulation of absorbed Pu was highest in the skeleton (83% ± 6%), followed by muscle (10% ± 9%), liver (6% ± 6%), kidneys (0.6% ± 0.4%), and blood (0.2%). Pu activity concentrations in lung tissues were elevated relative to the body average. Foetal transfer was higher in the wildlife data than in previous laboratory studies. The amount of Pu in the gastrointestinal tract was highly elevated relative to that absorbed within the body, potentially increasing transfer of Pu to wildlife and human consumers that may ingest gastrointestinal tract organs. The Pu distribution in the Maralinga mammalian wildlife generally aligns with previous studies related to environmental exposure (e.g. Pu in humans from worldwide fallout), but contrasts with the partitioning models that have traditionally been used for human worker-protection purposes (approximately equal deposition in bone and liver) which appear to under-predict the skeletal accumulation in environmental exposure conditions.
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Affiliation(s)
- M P Johansen
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - D P Child
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - E A Caffrey
- Oregon State University, Corvallis, OR, USA.
| | - E Davis
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - J J Harrison
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - M A C Hotchkis
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - T E Payne
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - A Ikeda-Ohno
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia; Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
| | - S Thiruvoth
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | | | - N A Beresford
- NERC Centre for Ecology & Hydrology, Lancaster, LA1 4AP, UK.
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Harrison JJ, Payne TE, Wilsher KL, Thiruvoth S, Child DP, Johansen MP, Hotchkis MAC. Measurement of (233)U/(234)U ratios in contaminated groundwater using alpha spectrometry. J Environ Radioact 2016; 151 Pt 3:537-541. [PMID: 26359847 DOI: 10.1016/j.jenvrad.2015.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 08/13/2015] [Accepted: 08/18/2015] [Indexed: 06/05/2023]
Abstract
The uranium isotope (233)U is not usually observed in alpha spectra from environmental samples due to its low natural and fallout abundance. It may be present in samples from sites in the vicinity of nuclear operations such as reactors or fuel reprocessing facilities, radioactive waste disposal sites or sites affected by clandestine nuclear operations. On an alpha spectrum, the two most abundant alpha emissions of (233)U (4.784 MeV, 13.2%; and 4.824 MeV, 84.3%) will overlap with the (234)U doublet peak (4.722 MeV, 28.4%; and 4.775 MeV, 71.4%), if present, resulting in a combined (233+234)U multiplet. A technique for quantifying both (233)U and (234)U from alpha spectra was investigated. A series of groundwater samples were measured both by accelerator mass spectrometry (AMS) to determine (233)U/(234)U atom and activity ratios and by alpha spectrometry in order to establish a reliable (233)U estimation technique using alpha spectra. The Genie™ 2000 Alpha Analysis and Interactive Peak Fitting (IPF) software packages were used and it was found that IPF with identification of three peaks ((234)U minor, combined (234)U major and (233)U minor, and (233)U major) followed by interference correction on the combined peak and a weighted average activity calculation gave satisfactory agreement with the AMS data across the (233)U/(234)U activity ratio range (0.1-20) and (233)U activity range (2-300 mBq) investigated. Correlation between the AMS (233)U and alpha spectrometry (233)U was r(2) = 0.996 (n = 10).
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Affiliation(s)
- Jennifer J Harrison
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia.
| | - Timothy E Payne
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - Kerry L Wilsher
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - Sangeeth Thiruvoth
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - David P Child
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - Mathew P Johansen
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
| | - Michael A C Hotchkis
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia
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Johansen MP, Child DP, Davis E, Doering C, Harrison JJ, Hotchkis MAC, Payne TE, Thiruvoth S, Twining JR, Wood MD. Plutonium in wildlife and soils at the Maralinga legacy site: persistence over decadal time scales. J Environ Radioact 2014; 131:72-80. [PMID: 24238919 DOI: 10.1016/j.jenvrad.2013.10.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 10/17/2013] [Accepted: 10/18/2013] [Indexed: 06/02/2023]
Abstract
The mobility of plutonium (Pu) in soils, and its uptake into a range of wildlife, were examined using recent and ∼25 year old data from the Taranaki area of the former Maralinga weapons test site, Australia. Since its initial deposition in the early 1960s, the dispersed Pu has been incorporated into the soil profile and food chain through natural processes, allowing for the study of Pu sequestration and dynamics in relatively undisturbed semi-arid conditions. The data indicate downward mobility of Pu in soil at rates of ∼0.2-0.3 cm per year for the most mobile fraction. As a result, while all of the Pu was initially deposited on the ground surface, approximately 93% and 62% remained in the top 0-2 cm depth after 25- and 50-years respectively. No large-scale lateral spreading of the Taranaki plume was observed. Pu activity concentrations in 0-1 cm soils with biotic crusts were not elevated when compared with nearby bare soils, although a small number of individual data suggest retention of Pu-containing particles may be occurring in some biotic crusts. Soil-to-animal transfer, as measured by concentration ratios (CRwo-soil), was 4.1E-04 (Geometric Mean (GM)) in mammals, which aligns well with those from similar species and conditions (such as the Nevada Test Site, US), but are lower than the GM of the international mammal data reported in the Wildlife Transfer Database (WTD). These lower values are likely due to the presence of a low-soluble, particulate form of the Pu in Maralinga soils. Arthropod concentration ratios (3.1E-03 GM), were similar to those from Rocky Flats, US, while values for reptiles (2.0E-02 GM) were higher than the WTD GM value which was dominated by data from Chernobyl. Comparison of uptake data spanning approximately 30 years indicates no decrease over time for mammals, and a potential increase for reptiles. The results confirm the persistence of bioavailable Pu after more than 50 years since deposition, and also the presence of larger-sized particles which currently affect CRwo-soil calculations, and which may serve as an ongoing source of bioavailable Pu as they are subjected to weathering into the future.
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Affiliation(s)
- M P Johansen
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, DC, NSW 2232, Australia.
| | - D P Child
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, DC, NSW 2232, Australia.
| | - E Davis
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, DC, NSW 2232, Australia.
| | - C Doering
- Australian Radiation Protection and Nuclear Safety Agency, Yallambie, Australia.
| | - J J Harrison
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, DC, NSW 2232, Australia.
| | - M A C Hotchkis
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, DC, NSW 2232, Australia.
| | - T E Payne
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, DC, NSW 2232, Australia.
| | - S Thiruvoth
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, DC, NSW 2232, Australia.
| | | | - M D Wood
- University of Salford, Manchester, UK.
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Button D, Hotchkis MAC, Milford GN. Design of a compact electron cyclotron resonance ion source for medium charge state light ions. Rev Sci Instrum 2012; 83:02A322. [PMID: 22380169 DOI: 10.1063/1.3669789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
At the Australian Nuclear Science and Technology Organization we are developing a new isotope ratio mass spectrometer based on the measurement of multiple charge state ions. We have carried out a review of our existing ECR ion source and identified a number of design flaws. For the new instrument, we are producing a new ECR source and have refined the design, in particular by using 3D simulations to improve the magnetic confinement field and by a combination of simulations and experiments to improve the design of the microwave coupling.
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Affiliation(s)
- D Button
- Australian Nuclear Science and Technology Organization, Sydney, NSW 2234, Australia.
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Hotchkis MAC, Button D, Waring CL. Use of multiply charged atomic ions for isotope ratio mass spectrometry. Rapid Commun Mass Spectrom 2008; 22:1408-1414. [PMID: 18384197 DOI: 10.1002/rcm.3513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We have investigated the use of multiply charged atomic ions for the measurement of isotopic ratios of gaseous and vapour samples. We use a mass spectrometer system incorporating an electron cyclotron resonance (ECR) ion source for this purpose. In the cases of carbon, nitrogen and oxygen, the selection of the 2+ atomic species is found to be the most effective for obtaining reliable isotopic ratios. Using samples of carbon dioxide, nitrogen, air and water vapour, we have demonstrated the determination of the isotopic ratios 13C/12C, 15N/14N, 17 O/16 O and 18 O/16 O. For oxygen, this technique offers an alternative to the equilibration or purification methods normally required to obtain isotopic ratios of water or other oxygen-containing samples. In particular, 17 O/16 O can be measured directly without isobaric interference from OH+. With typical ionization efficiencies of greater than 10%, ECR ion sources have the potential to enable measurements on very small samples. In addition to those evaluated in the present work, there is scope for application of this method to other sample types, to a variety of sampling methods, and to other elements.
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Affiliation(s)
- Michael A C Hotchkis
- Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234, Australia.
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Hotchkis MAC, Buckley D, Button D. Performance of an electron cyclotron resonance ion source designed for isotope ratio mass spectrometry. Rev Sci Instrum 2008; 79:02A304. [PMID: 18315094 DOI: 10.1063/1.2804878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We have designed, built, and tested an electron cyclotron resonance ion source suited to the needs of an experimental program examining new methods of isotope ratio mass spectrometry using multiply charged ions. Contaminant levels have been reduced to low levels. Sample absorption and desorption effects are under investigation and preliminary results are presented.
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Affiliation(s)
- M A C Hotchkis
- Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW, Australia.
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