Browsing by Author "Povinec, PP"

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    AMS measurement of 129I, 36C1 and 14C in underground waters from Mururoa and Fangataufa atolls
    (Elsevier, 2000-10) Jacobsen, GE; Hotchkis, MAC; Fink, D; Child, DP; Tuniz, C; Sacchi, E; Levins, DM; Povinec, PP; Mulsow, S
    AMS analyses of 36Cl, 129I and 14C in underground water have been performed as part of IAEA’s assessment of the radiological situation at Mururoa and Fangataufa atolls. The samples consisted of waters from monitoring wells, and from two cavity-chimneys created by underground nuclear tests. The water samples from the monitoring wells contained varying concentrations of radionuclides, with the highest concentrations of radionuclides found in the two test cavity-chimneys. A comparison of the concentrations of radionuclides determined by AMS, 36Cl and 129I, and with radionuclides determined using conventional methods, 3H, 90Sr and 137Cs, shows a reasonable correlation. However, some differences in behaviour, mainly attributed to differences in the sorption characteristics of the elements, are discernible. The concentrations of radionuclides in the underground environment were used to validate geosphere transport models. © 2000 Elsevier Science B.V.
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    Ultra-low-level determination of 236U in IAEA marine reference materials by ICPMS and AMS
    (Elsevier, 2008-06) Lee, SH; Povinec, PP; Wyse, E; Hotchkis, MAC
    The development of analytical procedures for the measurement of ultra-low levels of U-236 in marine samples using high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) and accelerator mass spectrometry (AMS) techniques are discussed and results are presented for IAEA reference materials-marine sediments (IAEA-135, 306, 384 and 385), marine biota (IAEA-134 and 414) and seawater (IAEA-381), collected in areas affected by nuclear reprocessing plants and nuclear weapons tests. The obtained minimum detection limit of the U-236/U-231 atom ratio was 1 x 10(-8) for AMS and 1 x 10(-6) for HR-ICPMS. © 2008, Elsevier Ltd.