Correction: Impact of lanthanide ion complexation and temperature on the chemical reactivity of ,,','-tetraoctyl diglycolamide (TODGA) with the dodecane radical cation.

Correction for 'Impact of lanthanide ion complexation and temperature on the chemical reactivity of ,,','-tetraoctyl diglycolamide (TODGA) with the dodecane radical cation' by Gregory P. Horne , , 2023, , 16404-16413, https://doi.org/10.

Multiscale Modeling of Plutonium Radiation Chemistry in Nitric Acid Solutions. 1. Cobalt-60 Gamma Irradiation of Pu(IV).

Careful manipulation of the plutonium oxidation states is essential in the study and utilization of its rich redox chemistry. To achieve this level of control, a comprehensive mechanistic understanding of radiation-induced plutonium redox chemistry is critical due to the unavoidable exposure of plutonium to ionizing radiation fields, both inherent and from in-process applications. To this end, we have developed an experimentally evaluated multiscale computer model for the prediction of gamma radiation-induced Pu(IV) redox chemistry in concentrated nitric acid solutions (1.

Design of a high-temperature cell for cobalt-60 irradiations of aqueous solutions with in situ UV-visible spectroscopy.

To understand the speciation of solutes in aqueous solutions in high temperature radiation environments, we report the design and fabrication of a custom-built, high temperature (≤300 °C) titanium irradiation cell with in situ optical spectroscopy capabilities, as afforded by coupled fiber optic cables. The wetted surfaces of the 8-inch tall cylindrical cell with 3.5 in.

Kinetics of the reaction of ferrous ions with hydroxyl radicals in the temperature range 25-300 °C.

The kinetics and mechanism of the reaction between OH radicals and ferrous ions in the temperature range 25-300 °C were studied using pulse radiolysis. At temperatures <150 °C the rate of reaction is essentially independent of temperature, while at temperatures >150 °C the activation energy is 45.8 ± 3.

High temperature gamma radiation-induced chromium redox chemistry spectroscopic measurements.

Chromium ions can make their way into the primary coolant of nuclear power reactors from the corrosion of stainless-steel reactor components, decreasing the material's corrosion resistance and resulting in increased transport of further corrosion products. Despite these potential effects, the radiation-induced redox speciation of chromium ions in aqueous solution is not well understood, especially at the elevated temperatures experienced by reactor coolants. In the present work, we report new experimental results demonstrating that in aerated aqueous solution, the radiolytic oxidation of Cr(III) to Cr(VI) occurs at pH 4, while the reduction of Cr(VI) to Cr(III) occurs at pH 2.

Kinetics of the Temperature-Dependent e and ⋅OH Radical Reactions with Cr(III) Ions in Aqueous Solutions.

The reactivity of chromium(III) species with the major oxidizing and reducing radiolysis products of water was investigated in aqueous solutions at temperatures up to 150 °C. The reaction between the hydrated electron (e ) and Cr(III) species showed a positive temperature dependence over this temperature range. The reaction was also studied in pH 2.

High-Temperature Reaction Kinetics of the e and HO Radicals with Iron(II) Ions in Aqueous Solutions.

Pulsed electron radiolysis was used to determine the chemical reaction kinetics and Arrhenius parameters for iron(II) reactions in aqueous solutions under irradiation. The second-order Fe reactions with the hydrated electron (e) and the perhydroxyl radical (HO), arising from water radiolysis, were measured to high temperatures using custom-built flow-through cells with a multichannel optical detection system. The reaction with the HO radical was found to proceed via the formation of a metal-ion adduct species, Fe-HO.

Impact of lanthanide ion complexation and temperature on the chemical reactivity of ,,','-tetraoctyl diglycolamide (TODGA) with the dodecane radical cation.

The impact of trivalent lanthanide ion complexation and temperature on the chemical reactivity of ,,','-tetraoctyl diglycolamide (TODGA) with the -dodecane radical cation (RH˙) has been measured by electron pulse radiolysis and evaluated by quantum mechanical calculations. Additionally, Arrhenius parameters were determined for the reaction of the non-complexed TODGA ligand with the RH˙ from 10-40 °C, giving the activation energy ( = 17.43 ± 1.

Impact of iodide ions on the speciation of radiolytic transients in molten LiCl-KCl eutectic salt mixtures.

The fate of fission-product iodine is critical for the deployment of next generation molten salt reactor technologies, owing to its volatility and biological impacts if it were to be released into the environment. To date, little is known on how ionizing radiation fields influence the redox chemistry, speciation, and transport of iodine in high temperature molten salts. Here we employ picosecond electron pulse irradiation techniques to elucidate for the first time the impact of iodide ions (I) on the speciation and chemical kinetics of the primary radiation-induced transient radicals generated in molten chloride salt mixtures (e and Cl˙) as a function of temperature (400-700 °C).

Second ionization constant of sulfuric acid in HO and DO from 150 to 300 °C at = 11.5 MPa using flow AC conductivity.

A custom-built flow-through AC conductivity instrument was used to measure the deuterium isotope effect on the ionization quotient of bisulfate from 150 to 300 °C, at = 11.5 MPa. Standardized solutions of KCl, HCl, KOH, KHSO, KSO, and HSO were prepared in light and heavy waters and their conductivities were measured and fitted with the Quint-Viallard conductivity model to obtain single ion conductivities at infinite dilution for K, Cl, H, OH, HSO, and SO.

Gamma Radiation-Induced Degradation of Acetohydroxamic Acid (AHA) in Aqueous Nitrate and Nitric Acid Solutions Evaluated by Multiscale Modelling.

Acetohydroxamic acid (AHA) has been proposed for inclusion in advanced, single-cycle, used nuclear fuel reprocessing solvent systems for the reduction and complexation of plutonium and neptunium ions. For this application, a detailed description of the fundamental degradation of AHA in dilute aqueous nitric acid is required. To this end, we present a comprehensive, multiscale computer model for the coupled radiolytic and hydrolytic degradation of AHA in aqueous sodium nitrate and nitric acid solutions.

Pulse Radiolysis and Transient Absorption of Aqueous Cr(VI) Solutions up to 325 °C.

Pulse radiolysis with a custom multichannel detection system has been used to measure the kinetics of the radiation chemistry reactions of aqueous solutions of chromium(VI) to 325 °C for the first time. Kinetic traces were measured simultaneously over a range of wavelengths and fit to obtain the associated high-temperature rate coefficients and Arrhenius parameters for the reactions of Cr(VI) + , Cr(VI) + H, and Cr(V) + OH. These kinetic parameters can be used to predict the behavior of toxic Cr(VI) in models of aqueous systems for applications in nuclear technology, industrial wastewater treatment, and chemical dosimetry.

Multiscale modelling of the radical-induced chemistry of acetohydroxamic acid in aqueous solution.

Acetohydroxamic acid (AHA) is a small organic acid with a wide variety of industrial, biological, and pharmacological applications. A deep fundamental molecular level understanding of the mechanisms responsible for the radical-induced reactions of AHA in these environments is necessary to predict and control their behaviour and elucidate their interplay with other attendant chemical species, for example, the oxidative degradation products of AHA. To this end, we present a comprehensive, multiscale computer model for interrogating the radical-induced degradation of AHA in acidic aqueous solutions.

Radiolytic Gas Production from Aluminum Coupons (Alloy 1100 and 6061) in Helium Environments-Assessing the Extended Storage of Aluminum Clad Spent Nuclear Fuel.

Corrosion of aluminium alloy clad nuclear fuel, during reactor operation and under subsequent wet storage conditions, promotes the formation of aluminium hydroxide and oxyhydroxide layers. These hydrated mineral phases and the chemisorbed and physisorbed waters on their surfaces are susceptible to radiation-induced processes that yield molecular hydrogen gas (H), which has the potential to complicate the long-term storage and disposal of aluminium clad nuclear fuel through flammable and explosive gas mixture formation, alloy embrittlement, and pressurization. Here, we present a systematic study of the radiolytic formation of H from aluminium alloy 1100 (AA1100) and 6061 (AA6061) coupons in "dry" (~0% relative humidity) and "wet" (50% relative humidity) helium environments.

Third dissociation constant of phosphoric acid in HO and DO from 75 to 300 °C at = 20.4 MPa using Raman spectroscopy and a titanium-sapphire flow cell.

A custom-built titanium-sapphire flow cell has been used with a confocal Raman microscope to collect solvent-corrected reduced isotropic spectra of sodium and potassium phosphate solutions in light and heavy water from 75 to 300 °C at 20.4 ± 0.4 MPa over a wide range of concentrations.

Second Dissociation Constant of Carbonic Acid in HO and DO from 150 to 325 °C at = 21 MPa Using Raman Spectroscopy and a Sapphire-Windowed Flow Cell.

Solvent-corrected reduced isotropic spectra of carbonate and bicarbonate in light and heavy water have been measured from 150 to 325 °C at 21 MPa using a confocal Raman microscope and a custom-built titanium flow cell with sapphire windows. The positions of the symmetric vibrational modes of CO and HCO/DCO were compared to density functional theory (DFT) calculations with a polarizable continuum model in light and heavy water. The experimental Raman peak positions shifted linearly toward lower wavenumbers with increasing temperatures.