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Title: Diffusive mass transport in agglomerated glassy fallout from a near-surface nuclear test

Abstract

Aerodynamically-shaped glassy fallout is formed when vapor phase constituents from the nuclear device are incorporated into molten carriers (i.e. fallout precursor materials derived from soil or other near-field environmental debris). The effects of speciation and diffusive transport of condensing constituents are not well defined in models of fallout formation. Previously we reported observations of diffuse micrometer scale layers enriched in Na, Fe, Ca, and 235U, and depleted in Al and Ti, at the interfaces of agglomerated fallout objects. Here in this paper, we derive the timescales of uranium mass transport in such fallout as it cools from 2500 K to 1500 K by applying a 1-dimensional planar diffusion model to the observed 235U/30Si variation at the interfaces. By modeling the thermal transport between the fireball and the carrier materials, the time of mass transport is calculated to be <0.6 s, <1 s, <2 s, and <3.5 s for fireball yields of 0.1 kt, 1 kt, 10 kt, and 100 kt respectively. Based on the calculated times of mass transport, a maximum temperature of deposition of uranium onto the carrier material of ~2200 K is inferred (1σ uncertainty of ~200 K). We also determine that the occurrence of micrometer scale layersmore » of material enriched in relatively volatile Na-species as well as more refractory Ca-species provides evidence for an oxygen-rich fireball based on the vapor pressure of the two species under oxidizing conditions. These results represent the first application of diffusion-based modeling to derive material transport, thermal environments, and oxidation-speciation in near-surface nuclear detonation environments.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1]
  1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1417958
Report Number(s):
LLNL-JRNL-728825
Journal ID: ISSN 0016-7037; TRN: US1801219
Grant/Contract Number:  
AC52-07NA27344; NA0000979
Resource Type:
Accepted Manuscript
Journal Name:
Geochimica et Cosmochimica Acta
Additional Journal Information:
Journal Volume: 223; Journal Issue: C; Journal ID: ISSN 0016-7037
Publisher:
The Geochemical Society; The Meteoritical Society
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; 38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY

Citation Formats

Weisz, David G., Jacobsen, Benjamin, Marks, Naomi E., Knight, Kim B., Isselhardt, Brett H., and Matzel, Jennifer E. Diffusive mass transport in agglomerated glassy fallout from a near-surface nuclear test. United States: N. p., 2017. Web. https://doi.org/10.1016/j.gca.2017.12.011.
Weisz, David G., Jacobsen, Benjamin, Marks, Naomi E., Knight, Kim B., Isselhardt, Brett H., & Matzel, Jennifer E. Diffusive mass transport in agglomerated glassy fallout from a near-surface nuclear test. United States. https://doi.org/10.1016/j.gca.2017.12.011
Weisz, David G., Jacobsen, Benjamin, Marks, Naomi E., Knight, Kim B., Isselhardt, Brett H., and Matzel, Jennifer E. Fri . "Diffusive mass transport in agglomerated glassy fallout from a near-surface nuclear test". United States. https://doi.org/10.1016/j.gca.2017.12.011. https://www.osti.gov/servlets/purl/1417958.
@article{osti_1417958,
title = {Diffusive mass transport in agglomerated glassy fallout from a near-surface nuclear test},
author = {Weisz, David G. and Jacobsen, Benjamin and Marks, Naomi E. and Knight, Kim B. and Isselhardt, Brett H. and Matzel, Jennifer E.},
abstractNote = {Aerodynamically-shaped glassy fallout is formed when vapor phase constituents from the nuclear device are incorporated into molten carriers (i.e. fallout precursor materials derived from soil or other near-field environmental debris). The effects of speciation and diffusive transport of condensing constituents are not well defined in models of fallout formation. Previously we reported observations of diffuse micrometer scale layers enriched in Na, Fe, Ca, and 235U, and depleted in Al and Ti, at the interfaces of agglomerated fallout objects. Here in this paper, we derive the timescales of uranium mass transport in such fallout as it cools from 2500 K to 1500 K by applying a 1-dimensional planar diffusion model to the observed 235U/30Si variation at the interfaces. By modeling the thermal transport between the fireball and the carrier materials, the time of mass transport is calculated to be <0.6 s, <1 s, <2 s, and <3.5 s for fireball yields of 0.1 kt, 1 kt, 10 kt, and 100 kt respectively. Based on the calculated times of mass transport, a maximum temperature of deposition of uranium onto the carrier material of ~2200 K is inferred (1σ uncertainty of ~200 K). We also determine that the occurrence of micrometer scale layers of material enriched in relatively volatile Na-species as well as more refractory Ca-species provides evidence for an oxygen-rich fireball based on the vapor pressure of the two species under oxidizing conditions. These results represent the first application of diffusion-based modeling to derive material transport, thermal environments, and oxidation-speciation in near-surface nuclear detonation environments.},
doi = {10.1016/j.gca.2017.12.011},
journal = {Geochimica et Cosmochimica Acta},
number = C,
volume = 223,
place = {United States},
year = {2017},
month = {12}
}

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Works referenced in this record:

The compositions, structures and origins of radioactive fall-out particles
journal, January 1960


Direct Pb Isotopic Analysis of a Nuclear Fallout Debris Particle from the Trinity Nuclear Test
journal, January 2017


A geochemical approach to constraining the formation of glassy fallout debris from nuclear tests
journal, December 2016

  • Bonamici, Chloë E.; Kinman, William S.; Fournelle, John H.
  • Contributions to Mineralogy and Petrology, Vol. 172, Issue 1
  • DOI: 10.1007/s00410-016-1320-2

When the dust settles: stable xenon isotope constraints on the formation of nuclear fallout
journal, November 2014


Constraints on fallout melt glass formation from a near-surface nuclear test
journal, July 2014

  • Eppich, Gary R.; Knight, Kim B.; Jacomb-Hood, Timothy W.
  • Journal of Radioanalytical and Nuclear Chemistry, Vol. 302, Issue 1
  • DOI: 10.1007/s10967-014-3293-9

High Temperature Vaporization Behavior of Oxides. I. Alkali Metal Binary Oxides
journal, January 1984

  • Lamoreaux, R. H.; Hildenbrand, D. L.
  • Journal of Physical and Chemical Reference Data, Vol. 13, Issue 1, p. 151-173
  • DOI: 10.1063/1.555706

High‐Temperature Vaporization Behavior of Oxides II. Oxides of Be, Mg, Ca, Sr, Ba, B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Zn, Cd, and Hg
journal, July 1987

  • Lamoreaux, R. H.; Hildenbrand, D. L.; Brewer, L.
  • Journal of Physical and Chemical Reference Data, Vol. 16, Issue 3
  • DOI: 10.1063/1.555799

Spatially-resolved analyses of aerodynamic fallout from a uranium-fueled nuclear test
journal, October 2015


Actinide diffusion in a haplogranitic melt: Effects of temperature, water content, and pressure
journal, June 1997


Chemical speciation of U, Fe, and Pu in melt glass from nuclear weapons testing
journal, May 2016

  • Pacold, J. I.; Lukens, W. W.; Booth, C. H.
  • Journal of Applied Physics, Vol. 119, Issue 19
  • DOI: 10.1063/1.4948942

Vapor fractionation of silicate melts at high temperatures and atmospheric pressures
journal, July 1967


Deposition of vaporized species onto glassy fallout from a near-surface nuclear test
journal, March 2017

  • Weisz, David G.; Jacobsen, Benjamin; Marks, Naomi E.
  • Geochimica et Cosmochimica Acta, Vol. 201
  • DOI: 10.1016/j.gca.2016.10.036