Iodine 129 levels from R/V Ka`imikai-O-Kanaloa KOK1108 from June 2011 (Fukushima Radionuclide Levels project)

Dataset: Fukushima Radionuclide Iodine 129 levelsIodine 129 data collected using paired Niskin-CTD rosette from R/V Ka`imikai-O-Kanaloa KOK1108 in June 2011 For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/716480Gordon and Betty Moore Foundation (GBMF) GBMF300

Accelerator mass spectrometry of Strontium-90 for homeland security, environmental monitoring, and human health Nuclear Instruments and Methods in Physics Research B: Beam Interactions with Material and Atoms Accelerator mass spectrometry of Strontium-90

Abstract Strontium-90 is one of the most hazardous materials managed by agencies charged with protecting the public from radiation. Traditional radiometric methods have been limited by low sample throughput and slow turnaround times. Mass spectrometry offers the advantage of shorter analysis times and the ability to measure samples immediately after processing, however conventional mass spectrometric techniques are susceptible to molecular isobaric interferences that limit their overall sensitivity. In contrast, accelerator mass spectrometry is insensitive to molecular interferences and we have therefore begun developing a method for determination of 90 Sr by accelerator mass * Corresponding author: 7000 East Avenue, L-397; Livermore, CA 94551; +1-925-423-9012; [email protected] 2 spectrometry. Despite a pervasive interference from 90 Zr, our initial development has yielded an instrumental background of ~10 8 atoms (75 mBq) per sample. Further refinement of our system (e.g., redesign of our detector, use of alternative target materials) is expected to push the background below 10 6 atoms, close to the theoretical limit for AMS. Once we have refined our system and developed suitable sample preparation protocols, we will utilize our capability in applications to homeland security, environmental monitoring, and human health

Plutonium(IV) and (V) Sorption to Goethite at Sub-Femtomolar to Micromolar Concentrations: Redox Transformations and Surface Precipitation

Pu­(IV) and Pu­(V) sorption to goethite was investigated over a concentration range of 10^–15–10^–5 M at pH 8. Experiments with initial Pu concentrations of 10^–15 – 10^–8 M produced linear Pu sorption isotherms, demonstrating that Pu sorption to goethite is not concentration-dependent across this concentration range. Equivalent Pu­(IV) and Pu­(V) sorption <i>K</i>_d values obtained at 1 and 2-week sampling time points indicated that Pu­(V) is rapidly reduced to Pu­(IV) on the goethite surface. Further, it suggested that Pu surface redox transformations are sufficiently rapid to achieve an equilibrium state within 1 week, regardless of the initial Pu oxidation state. At initial concentrations >10^–8 M, both Pu oxidation states exhibited deviations from linear sorption behavior and less Pu was adsorbed than at lower concentrations. NanoSIMS and HRTEM analysis of samples with initial Pu concentrations of 10^–8 – 10^–6 M indicated that Pu surface and/or bulk precipitation was likely responsible for this deviation. In 10^–6 M Pu­(IV) and Pu­(V) samples, HRTEM analysis showed the formation of a body centered cubic (bcc) Pu₄O₇ structure on the goethite surface, confirming that reduction of Pu­(V) had occurred on the mineral surface and that epitaxial distortion previously observed for Pu­(IV) sorption occurs with Pu­(V) as well

Production and Isolation of Homologs of Flerovium and Element 115 at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry

New procedures have been developed to isolate no-carrier-added (NCA) radionuclides of the homologs and pseudo-homologs of flerovium (Hg, Sn) and element 115 (Sb), produced by 12–15 MeV proton irradiation of foil stacks with the tandem Van-de-Graaff accelerator at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry (CAMS) facility. The separation of 113Sn from natIn foil was performed with anion-exchange chromatography from hydrochloric and nitric acid matrices. A cation-exchange chromatography method based on hydrochloric and mixed hydrochloric/hydroiodic acids was used to separate 124Sb from natSn foil. A procedure using Eichrom TEVA resin was developed to separate 197Hg from Au foil. These results demonstrate the suitability of using the CAMS facility to produce NCA radioisotopes for studies of transactinide homologs