Spectroscopic investigation on the formation of hypochlorite by alpha radiolysis in concentrated NaCl solutions

Kelm, M.; Pashalidis, Ioannis; Kim, J.I

doi:10.1016/s0969-8043(99)00113-x

Cited by 24 publications

(26 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The α-irradiation of pH 12 NaCl solutions exposed to 238 Pu resulted in increasing amounts of OCl − with both increasing salt concentration and absorbed dose [91]. This autoradiolysis results in the oxidation of insoluble Pu IV to Pu VI , and its subsequent complexation as PuO 2 (OH)OCl, or PuO 2 (ClO) 2 [92].…”

Section: Effects On Actinide Oxidation States In Salt Brinementioning

confidence: 99%

Radiation chemical effects on radiochemistry: A review of examples important to nuclear power

Mincher¹,

Mezyk

2009

Radiochimica Acta

View full text Add to dashboard Cite

Radiolysis / Linear energy transfer / Redox reactions / Ligand degradation / Free radicals / Solvent extractionSummary. Radiochemistry deals with the chemistry of the radioactive elements. In the nuclear industry successful fuel reprocessing, high-level waste treatment, and long-term storage of spent fuel depend on an understanding of the radiochemistry of actinides and fission products in these settings. Radiation chemistry is concerned with the chemical effects of ionizing radiation, with the most common types of radiation encountered by the radiochemist being low linear energy transfer (LET) β − and γ radiation, and higher LET α radiation. These radiations can have profound and important effects on radiochemistry, including changes in metal oxidation states and degradation of the organic ligands designed to complex radioelements. This may occur by direct action of the incident radiation on compounds present with high abundance or by reaction with radiolytically produced reactive species for trace components, such as the complexing agents. This review examines the role of reactive species created in irradiated aqueous and organic solution and their effects on radiochemistry. The sources and nature of these reactive species are discussed. Examples of radiation chemical effects are provided related to solvent extraction of the actinides from acidic solution, metal complexation and technetium redox chemistry in alkaline tank waste, and the corrosion of spent fuel stored in repository brine.

show abstract

Section: Effects On Actinide Oxidation States In Salt Brinementioning

confidence: 99%

Radiation chemical effects on radiochemistry: A review of examples important to nuclear power

Mincher¹,

Mezyk

2009

Radiochimica Acta

View full text Add to dashboard Cite

show abstract

“…Radiolysis of water by high‐energy radiation is known to produce a combination of hydroxyl radicals (•OH) and solvated electrons / hydrogen atoms (•H), which result after the initial ionization of water to H 2 O •+ . Our curiosity was piqued by reports that radiolysis of NaCl solutions generate hypochlorite ( − OCl) through a mechanism thought to be initiated by the scavenging of •OH by Cl − , although mechanisms involving direct ionization of Cl − , as well as H 2 O •+ hole‐scavenging, likely contribute significantly at large chloride concentrations. Moreover, hypochlorous acid (HOCl) as well as chloramine (NH 2 Cl, formed in water from NH 3 and HOCl) react rapidly with − CN to produce ClCN ( k HOCl =1.22•10 9 M –1 s –1 ; [H 3 O + ]‐assisted k NH2Cl =4.32•10 10 M –2 s –1 ).…”

Section: Introductionmentioning

confidence: 99%

Radiolytic Synthesis of Cyanogen Chloride, Cyanamide and Simple Sugar Precursors

Hongo

Yoda

et al. 2018

ChemistrySelect

View full text Add to dashboard Cite

Chemical evolution, from simple molecules to complex systems, is fundamental to modern origins of life research, and complex reaction networks are often supposed to have operated on the early Earth. Herein, a variety of compounds useful particularly for RNA synthesis − namely, cyanogen chloride, cyanamide, and nitrile precursors to simple sugars − are produced in short order by a chemical reaction network starting from hydrogen cyanide and driven by gamma radiolysis. The radiolytic yield of cyanamide was found to be proportional to the concentration of chloride, an often overlooked spectator anion. Aqueous irradiation of hydrogen cyanide in the presence of sodium chloride also affords cyanogen chloride, a possible intermediate in the radiolytic synthesis of cyanamide. Meanwhile, the synthesis of simple sugar precursors is proposed to proceed through a Kiliani‐Fischer homologation mechanism made possible by the reducing power of the solvated electron and hydrogen atom. Such a reaction network has the potential to serve as a model for better understanding and engineering chemical evolution of complex mixtures in the laboratory that could have happened on the early Earth.

show abstract

“…The gas formation does not depend on pH and upon the distribution of the α-emitter in the solution. The solutions with doped pellets, where the primary products are formed in a volume of only 4 mm 3 give the same results as the solutions with Pu homogeneously distributed in 20 ml having the same mean dose. In addition to the gases, hypochlorite (figure 3), chlorite and chlorate (figure 4) are formed.…”

Section: Resultsmentioning

confidence: 55%

“…In the past, the αand γ-radiolysis of concentrated chloride brines was investigated with respect to the final disposal of spent nuclear fuel in a rock salt formation. [1][2][3][4] The radiation chemical processes in the solution could be simulated with a reaction kinetic model. 2,4,5 The first step in the mobilization of radionuclides from spent fuel is oxidative dissolution of the fuel matrix.…”

Section: Introductionmentioning

confidence: 99%

Radiolysis and corrosion of238Pu-doped UO2 pellets in chloride brine

Kelm

Bohnert

2002

J Chem Sci

View full text Add to dashboard Cite

Deaerated 5 M NaCl solution is irradiated in the presence of UO 2 pellets with α-radiation from 238 Pu. Experiments are conducted with 238 Pu doped pellets and others with 238 Pu dissolved in the brine. The radiolysis products and yields of mobilized U and Pu from the oxidative dissolution of UO 2 are determined. Results found for radiolysis products and for the oxidation/dissolution of pellets immersed in Pu containing brine are similar to results for Pu doped pellets, where the radiation chemical processes occur only in the liquid layer of some 10 µm thickness adjacent to the pellet. The yield of radiolysis products is comparable to earlier results, that of mobilized U from the pellets is < 1% of the total amount of oxidized species. Thus, the radiation chemical yield (G-value) for mobilized hexavalent U is < 0⋅01 ions/ 100 eV. In spite of the low radiation yield for the corrosion, the rate of UO 2 dissolution is higher than expected for the concentrations of long-lived oxidizing radiolysis compounds found in the solutions.

show abstract

Spectroscopic investigation on the formation of hypochlorite by alpha radiolysis in concentrated NaCl solutions

Cited by 24 publications

References 18 publications

Radiation chemical effects on radiochemistry: A review of examples important to nuclear power

Radiation chemical effects on radiochemistry: A review of examples important to nuclear power

Radiolytic Synthesis of Cyanogen Chloride, Cyanamide and Simple Sugar Precursors

Radiolysis and corrosion of238Pu-doped UO2 pellets in chloride brine

Contact Info

Product

Resources

About