title: Plutonium isotopes derived from Nagasaki atomic bomb in the sediment of Nishiyama reservoir at Nagasaki, Japan.
abstract: The source of plutonium in sediments deposited at Nishiyama reservoir at Nagasaki was characterized by their (240)Pu/(239)Pu atom ratio. The average ratio was approximately 0.03, except in two layers. The main source of the plutonium was the Nagasaki atomic bomb. The plutonium continues to flow into the reservoir even now. The (240)Pu/(239)Pu atom ratios in two layers were higher than the average, which showed that plutonium in these layers were made of those of nuclear tests added to those of the atomic bomb.
authors.affiliation: Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan. kokubu.yoko@jaea.go.jp <kokubu.yoko@jaea.go.jp>
authors.forename: Y
authors.initials: Y
authors.lastname: Saito-Kokubu
authors.forename: F
authors.initials: F
authors.lastname: Esaka
authors.forename: K
authors.initials: K
authors.lastname: Yasuda
authors.forename: M
authors.initials: M
authors.lastname: Magara
authors.forename: Y
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: S
authors.initials: S
authors.lastname: Sakurai
authors.forename: S
authors.initials: S
authors.lastname: Usuda
authors.forename: H
authors.initials: H
authors.lastname: Yamazaki
authors.forename: S
authors.initials: S
authors.lastname: Yoshikawa
authors.forename: S
authors.initials: S
authors.lastname: Nagaoka
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis; D019015:Geologic Sediments / Q000737:chemistry*; D007564:Japan; D009689:Nuclear Warfare; D011005:Plutonium / Q000032:analysis*; D011847:Radioactive Fallout / Q000032:analysis; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D012990:Soil Pollutants, Radioactive; D011005:Plutonium