Isotopic Composition and Distribution of Plutonium in Northern South China Sea Sediments Revealed Continuous Release and Transport of Pu from the Marshall Islands
- 6 March 2014
- journal article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 48 (6), 3136-3144
- https://doi.org/10.1021/es405363q
Abstract
The (239+240)Pu activities and (240)Pu/(239)Pu atom ratios in sediments of the northern South China Sea and its adjacent Pearl River Estuary were determined to examine the spatial and temporal variations of Pu inputs. We clarified that Pu in the study area is sourced from a combination of global fallout and close-in fallout from the Pacific Proving Grounds in the Marshall Islands where above-ground nuclear weapons testing was carried out during the period of 1952-1958. The latter source dominated the Pu input in the 1950s, as evidenced by elevated (240)Pu/(239)Pu atom ratios (>0.30) in a dated sediment core. Even after the 1950s, the Pacific Proving Grounds was still a dominant Pu source due to continuous transport of remobilized Pu from the Marshall Islands, about 4500 km away, along the North Equatorial Current followed by the transport of the Kuroshio current and its extension into the South China Sea through the Luzon Strait. Using a simple two end-member mixing model, we have quantified the contributions of Pu from the Pacific Proving Grounds to the northern South China Sea shelf and the Pearl River Estuary are 68% ± 1% and 30% ± 5%, respectively. This study also confirmed that there were no clear signals of Pu from the Fukushima Daiichi Nuclear Power Plant accident impacting the South China Sea.Keywords
This publication has 58 references indexed in Scilit:
- Isotopic evidence of plutonium release into the environment from the Fukushima DNPP accidentScientific Reports, 2012
- Input of anthropogenic radionuclides into the World OceanDeep Sea Research Part II: Topical Studies in Oceanography, 2003
- Sources and Migration of Plutonium in Groundwater at the Savannah River SiteEnvironmental Science & Technology, 2002
- Size-fractionated plutonium isotopes in a coastal environmentJournal of Environmental Radioactivity, 2001
- Iodine-129 and plutonium isotopes in Arctic kelp as historical indicators of transport of nuclear fuel-reprocessing wastes from mid-to-high latitudes in the Atlantic OceanMarine Biology, 1998
- Plutonium from European reprocessing operations — Its behaviour in the marine environmentApplied Radiation and Isotopes, 1995
- The transfer of reprocessing wastes from north-west Europe to the ArcticDeep Sea Research Part II: Topical Studies in Oceanography, 1995
- Plutonium isotopes in the surface air in Japan: Effect of Chernobyl accidentJournal of Radioanalytical and Nuclear Chemistry, 1990
- The geochemistry of plutonium in fresh and marine water environmentsEarth-Science Reviews, 1983
- Plutonium in the environment - A review.Journal of Radiation Research, 1980