Radionuclides and stable elements in vegetation in Australian arid environments: Concentration ratios and seasonal variation

Influence of Temperature History and Flow Mixing on the Vapor-Phase Speciation of Uranium Oxide Nanoparticles

“…Fallout is the remnant radioactive material that condenses from hot vapor into particulates in milliseconds to seconds following a nuclear explosion. , Specific conditions of the fireball such as the cooling rate, mixing, and redox conditions can impact the chemical and physical properties of fallout, including its composition, shape, size, and the oxidation state of the metal species. To understand and plan for the impact of fallout generated by reactor meltdowns or weapon detonations on the environment and population, it is necessary to understand these chemical and physical characteristics as they control subsequent toxicity, solubility, − transport, , and interactions with the local flora . While the analysis of historic nuclear debris has provided extensive insight into the chemical conditions existing in the fireball, , phenomenon such as anomalous fractionation , can heavily complicate the analysis of these samples.…”

“…To understand and plan for the impact of fallout generated by reactor meltdowns or weapon detonations on the environment and population, it is necessary to understand these chemical and physical characteristics as they control subsequent toxicity, 3 solubility, 4−6 transport, 7,8 and interactions with the local flora. 9 While the analysis of historic nuclear debris has provided extensive insight into the chemical conditions existing in the fireball, 10,11 phenomenon such as anomalous fractionation 1,12 can heavily complicate the analysis of these samples. Furthermore, the effects of conditions such as humidity and cooling history on the chemical speciation of radiological materials are largely unknown, making it difficult to directly link different initial conditions to fallout characteristics in historic samples.…”

“…Laser ablation and PFR setups both use plasma (generated via a laser or an inductively coupled RF coil, respectively) to vaporize a sample of interest (typically a metal), and the resulting fallout-like product, typically a metal oxide, condenses from the vapor phase as the system cools. − Laser ablation experiments, which operate on microsecond time scales, are usually conducted in sealed chambers and thereby provide full control of the gas composition in which the fallout forms. Less flexibility is afforded with the sample geometry, however, as these experiments most commonly utilize solid targets.…”