title: Isotopic ratio of 129I/127I in seaweed measured by neutron activation analysis with gamma-gamma coincidence.
abstract: 129I is a long-lived (1.6 x 10(7) y) radionuclide that is produced in nature as the result of spontaneous fission of heavy elements and reaction of xenon with cosmic rays. Recently, however, artificial sources from nuclear power plants and nuclear test explosions have become a significant component of environmental radioactive iodine. Coincidence gamma-ray detection using Ge detectors makes it possible to simultaneously resolve the numerous gamma-rays produced by neutron activation. In this study, the coincidence gamma-ray detection technique was combined with neutron activation analysis to determine the radioactive iodine composition of seaweed. The ratio of 129I/127I in this common Japanese food item collected from the Ibaraki prefecture has been derived without the need for radiochemical purification. The isotopic ratio of 129I/127I in Kajime algae is 3.5(5) x 10(-10).
authors.affiliation: Japan Atomic Energy Research Institute, Tokai, Ibaraki. toh@jball4.tokai.jaeri.go.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Toh
authors.forename: Y
authors.initials: Y
authors.lastname: Hatsukawa
authors.forename: M
authors.initials: M
authors.lastname: Oshima
authors.forename: N
authors.initials: N
authors.lastname: Shinohara
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
authors.forename: K
authors.initials: K
authors.lastname: Kushita
authors.forename: T
authors.initials: T
authors.lastname: Ueno
mesh_terms: D005720:Gamma Rays; D007456:Iodine Isotopes / Q000032:analysis*; D007457:Iodine Radioisotopes / Q000032:analysis*; D009501:Neutron Activation Analysis / Q000379:methods; D015203:Reproducibility of Results; D012624:Seaweed / Q000737:chemistry*
chemical_list: D007456:Iodine Isotopes; D007457:Iodine Radioisotopes