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

Adams, Carl E.; Farlow, N. H.; Schell, W.R.

doi:10.1016/0016-7037(60)90016-8

Cited by 87 publications

(52 citation statements)

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“…In summary, the co-location of Na-and Ca-species would be possible in an oxygen-rich environment (which the fireball is theorized to be during fallout formation [6,15]), where there was substantial contribution of Ca to the vapor from an additional source undergoing continuous fractionation (as described in Section 4.3). The assertion that sodium deposition is the result of an oxygenated fireball is in apparent contrast to what was shown by Cassata et al (2014), where measurements of volumetric xenon isotope concentrations indicate that the fireball was in a reducing state [54].…”

Section: Discussionmentioning

confidence: 99%

“…However, in an oxygen-rich environment, the vapor pressure of Na approaches atmospheric pressure at around 2200 K [103]; this does not happen until temperatures cool to 1400 K in reducing conditions. Thus, co-location of Na-and Ca-species would be possible in an oxygen-rich environment (which the fireball is theorized to be during fallout formation [6,15]), where there was substantial contribution of Ca to the vapor from an additional source undergoing continuous fractionation (as described in Section 4.3).…”

Section: Chapter 5 Diffusive Mass Transport In Agglomerates From a Dmentioning

confidence: 99%

“…The autoradiographs revealed patterns of radionuclide incorporation which were used to develop fallout formation models [15,16]. For example, studies commonly reported a relative increase in the radionuclide activity at the surface of fallout objects, which suggested a fractionation sequence based on condensation temperature, wherein more refractory (higher vaporization temperature) species condensed early, while the more volatile species condensed later, at cooler fireball temperatures [6,12]. Autoradiography, however, cannot determine the identity of these radionuclides, and the spatial resolution of this technique is typically limited to 10's of microns.…”

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confidence: 99%

“…These objects, which formed in the fireball and quenched prior to hitting the ground, would have had the highest probability of interaction and incorporation of vaporized device material. Fallout has been a subject of study over several decades to understand how radionuclides are incorporated into fallout, and determine how radionuclides would be distributed over a geographic area following a nuclear event [6,10,11,12]. Understanding how radionuclides are distributed around ground zero is essential to public safety and strategic deployment of emergency personnel in the event of a nuclear detonation [2].…”

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confidence: 99%

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Mass Transport of Condensed Species in Aerodynamic Fallout Glass from a Near-Surface Nuclear Test

Weisz¹

2016

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In a near-surface nuclear explosion, vaporized device materials are incorporated into molten soil and other carrier materials, forming glassy fallout upon quenching. Mechanisms by which device materials mix with carrier materials have been proposed, however, the specific mechanisms and physical conditions by which soil and other carrier materials interact in the fireball, as well as the subsequent incorporation of device materials with carrier materials, are not well constrained. A surface deposition layer was observed preserved at interfaces where two aerodynamic fallout glasses agglomerated and fused. Eleven such boundaries were studied using spatially resolved analyses to better understand the vaporization and condensation behavior of species in the fireball. Using nano-scale secondary ion mass spectrometry (NanoSIMS), we identified higher concentrations of uranium from the device in 7 of the interface layers, as well as isotopic enrichment (>75% 235 U) in 9 of the interface layers. Major element analysis of the interfaces revealed the deposition layer to be chemically enriched in Fe-, Ca-and Na-bearing species and depleted in Ti-and Al-bearing species. The concentration profiles of the enriched species at the interface are characteristic of diffusion. Three of the uranium concentration profiles were fit with a modified Gaussian function, representative of 1-D diffusion from a planar source, to determine time and temperature parameters of mass transport. By using a historical model of fireball temperature to simulate the cooling rate at the interface, the temperature of deposition was estimated to be ∼2200 K, with 1σ uncertainties in excess of 140 K. The presence of Na-species in the layers at this estimated temperature of deposition is indicative of an oxygen rich fireball. The notable depletion of Al-species, a refractory oxide that is highly abundant in the soil, together with the enrichment of Ca-, Fe-, and 235 U-species, suggests an anthropogenic source of the enriched species, together with a continuous chemical fractionation process as these species condensed.

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Section: Discussionmentioning

confidence: 99%

Section: Chapter 5 Diffusive Mass Transport In Agglomerates From a Dmentioning

confidence: 99%

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confidence: 99%

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Mass Transport of Condensed Species in Aerodynamic Fallout Glass from a Near-Surface Nuclear Test

Weisz¹

2016

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“…Freiling hat discussed fractionation in several papers (4,5,6). The work of Adams et al (7,8) and that of Norman et al (9,10) is of interest in consideration of fractionation processes. Many others have made contributions to fractionation information; among them are those who have participated in symposia (11,12) on fallout.…”

Section: Introductionmentioning

confidence: 99%

Gamma-Ray Spectra of Fractionated Fission Products

Bunney¹,

Sam²

1971

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Plutonium: Radionuclides

Neu¹,

Goff²,

Runde³

2005

Encyclopedia of Inorganic Chemistry

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Plutonium is the most debated actinide element because of its dual use in devastating nuclear weapons and beneficial generation of nuclear energy. Plutonium metal exists in several allotropic phases and plutonium in solution exhibits a rich and complex chemistry. The ability to exist in up to four oxidation states makes plutonium unique among all elements. Pu(III) and Pu(VI) form only under reducing or oxidizing conditions, respectively; whereas Pu(IV) and Pu(V) have broad stability ranges within the geochemical bounds of environmental systems. When Pu(IV) is above trace concentration and particulate matter is present, then solids or suspended colloids are the predominant chemical forms. In contrast, Pu(V), as PuO $_{2}^{+}$ , has relatively higher solubility as an aquo species or a monomeric complex of natural ligands (hydroxide, chloride, sulfate, etc.). Stronger complexing, polydentate ligands, such as carbonate and organics, tend to increase plutonium solubility by forming very stable Pu(IV) complexes. Minerals, high molecular weight organic matter, and bacteria can either increase or decrease the solubility of plutonium, depending upon their chemical properties, mechanisms of interaction, and the geochemical conditions of the surrounding environment. Plutonium generally has very low solubility, low mobility, and few health consequences from environmental forms, and therefore poses little risk to living systems under nearly all conditions. This article provides a brief overview of the chemistry and behavior of plutonium in aqueous solutions and in the environment.

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

Cited by 87 publications

References 3 publications

Mass Transport of Condensed Species in Aerodynamic Fallout Glass from a Near-Surface Nuclear Test

Mass Transport of Condensed Species in Aerodynamic Fallout Glass from a Near-Surface Nuclear Test

Gamma-Ray Spectra of Fractionated Fission Products

Plutonium: Radionuclides

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