Spatially-resolved analyses of aerodynamic fallout from a uranium-fueled nuclear test

L A Lewis; K B Knight; J E Matzel; S G Prussin; M M Zimmer; W S Kinman; F J Ryerson; I D Hutcheon

doi:10.1016/j.jenvrad.2015.04.006

Spatially-resolved analyses of aerodynamic fallout from a uranium-fueled nuclear test

J Environ Radioact. 2015 Oct:148:183-95. doi: 10.1016/j.jenvrad.2015.04.006. Epub 2015 Jul 28.

Authors

L A Lewis¹, K B Knight², J E Matzel², S G Prussin³, M M Zimmer⁴, W S Kinman⁴, F J Ryerson², I D Hutcheon²

Affiliations

¹ Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA; Department of Nuclear Engineering, University of California, Berkeley, 4113 Etcheverry Hall MC 1730, Berkeley, CA 94720, USA. Electronic address: lewis105@llnl.gov.
² Glenn T. Seaborg Institute, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA.
³ Department of Nuclear Engineering, University of California, Berkeley, 4113 Etcheverry Hall MC 1730, Berkeley, CA 94720, USA.
⁴ Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87544, USA.

PMID: 26225462
DOI: 10.1016/j.jenvrad.2015.04.006

Abstract

Five silicate fallout glass spherules produced in a uranium-fueled, near-surface nuclear test were characterized by secondary ion mass spectrometry, electron probe microanalysis, autoradiography, scanning electron microscopy, and energy-dispersive x-ray spectroscopy. Several samples display compositional heterogeneity suggestive of incomplete mixing between major elements and natural U ((238)U/(235)U = 0.00725) and enriched U. Samples exhibit extreme spatial heterogeneity in U isotopic composition with 0.02 < (235)U/(238)U < 11.84 among all five spherules and 0.02 < (235)U/(238)U < 7.41 within a single spherule. In two spherules, the (235)U/(238)U ratio is correlated with changes in major element composition, suggesting the agglomeration of chemically and isotopically distinct molten precursors. Two samples are nearly homogenous with respect to major element and uranium isotopic composition, suggesting extensive mixing possibly due to experiencing higher temperatures or residing longer in the fireball. Linear correlations between (234)U/(238)U, (235)U/(238)U, and (236)U/(238)U ratios are consistent with a two-component mixing model, which is used to illustrate the extent of mixing between natural and enriched U end members.

Keywords: Device debris; Fallout; Nuclear forensics; SIMS; Trinitite.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Nuclear Weapons
Radiation Monitoring / methods*
Radioactive Fallout / analysis*
Soil Pollutants, Radioactive / analysis*
Spatial Analysis
Uranium / analysis*

Substances

Radioactive Fallout
Soil Pollutants, Radioactive
Uranium