Plutonium(III) oxidation under α-irradiation in nitric acid solutions

Andreychuk, N. N.; Frolov, A. A.; Rotmanov, K. V.; Vasiliev, Victor Ya.

doi:10.1007/bf02039611

Cited by 15 publications

(6 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is evident from the above equilibria that what was once a single valency Pu(IV) system progressively becomes a multivalency system reflective of eq , containing Pu(III), Pu(IV), Pu(V), and Pu(VI) in various proportions. All of these plutonium oxidation states have been found to interact with the radiolysis products of aqueous HNO 3 to some extent. ,− H 2 O 2 plays a significant role in determining the radiolytic yield of HNO 2 and can also be slowly reduced by Pu(III) and oxidized by Pu(IV) and Pu(VI) (reactions –). ,, …”

Section: Discussionmentioning

confidence: 99%

“…The resulting Pu(IV) and Pu(V) can be expected to slowly undergo disproportionation to ultimately yield Pu(VI) and Pu(III). The excess Pu(III) may provide some explanation as to why the initial yield of HNO 2 (<400 Gy) in Figure , from plutonium α-decay, is as high as the upper limit established by Kazanjian et al Pu(III) exhibits an autocatalytic process involving nitrogen peroxide (N 2 O 4 ), a precursor to HNO 2 , given by reaction . − …”

Section: Discussionmentioning

confidence: 99%

“…Nitrous acid (HNO 2 ) is the principal radiolytic degradation product of nitric acid and a significant contributor to altering both the physical and chemical properties of nitric acid media, and its corrosion potential. ,− Furthermore, nitrous acid exhibits complex redox relationships with a number of actinides, of which its reactions with plutonium and neptunium are of concern to the performance of reprocessing solvent systems. − ,− The radiolytic formation of nitrous from aerated nitric acid can be described by the following simple reaction scheme. − Water radiolysis: Nitrate radiolysis: Nitric acid radiolysis: Diffusion-reaction chemistry of nitrogen species: This reaction scheme is not exhaustive, as nitrous acid and its precursors are subject to a plethora of secondary reactions…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Plutonium and Americium Alpha Radiolysis of Nitric Acid Solutions

et al. 2017

View full text Add to dashboard Cite

The yield of HNO, as a function of absorbed dose and HNO concentration, from the α-radiolysis of aerated HNO solutions containing plutonium or americium has been investigated. There are significant differences in the yields measured from solutions of the two different radionuclides. For 0.1 mol dm HNO solutions, the radiolytic yield of HNO produced by americium α-decay is below the detection limit, whereas for plutonium α-decay the yield is considerably greater than that found previously for γ-radiolysis. The differences between the solutions of the two radionuclides are a consequence of redox reactions involving plutonium and the products of aqueous HNO radiolysis, in particular HO and HNO and its precursors. This radiation chemical behavior is HNO concentration dependent with the differences between plutonium and americium α-radiolysis decreasing with increasing HNO concentration. This change may be interpreted as a combination of α-radiolysis direct effects and acidity influencing the plutonium oxidation state distribution, which in turn affects the radiation chemistry of the system.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Plutonium and Americium Alpha Radiolysis of Nitric Acid Solutions

et al. 2017

View full text Add to dashboard Cite

show abstract

“…He justifies the empirical rate law found by Koltunov and Marchenko (1973) Andreychuk, et al (1990) have also measured rates for Pu(III) oxidation in nitric acid. They found that the rate of oxidation is controlled by chemical mechanisms rather than radiolysis at nitric acid concentrations greater than 0.55 M. The Pu(IV) concentration versus time curves cover a nitric acid concentration range of 0.12e2.90 M. A comparison of rates for reoxidation from the papers of Andreychuk et al and Koltunov and Marchenko is very good, providing strong support for the Pu(III) reoxidation part of the model.…”

Section: Resultsmentioning

confidence: 56%

“…The kinetics of Reaction (12) has been determined by Barney (1976). The kinetics of Reaction (13) has been determined by Newton (2002), Koltunov and Marchenko (1973), Andreychuk, Frolov, Rotmanov, and Vasiliev (1990), and by Dukes (1960). If these reaction mechanisms are correct, the HANeH-NO 3 ePu(III) solutions are inherently unstable because of the continuous reoxidation of Pu(III) with HNO 3 and subsequent reduction of Pu(IV) with HAN.…”

Section: Resultsmentioning

confidence: 99%

Model for predicting hydroxylamine nitrate stability in plutonium process solutions

Barney

Duval

2011

Journal of Loss Prevention in the Process Industries

View full text Add to dashboard Cite

Plutonium: Radionuclides

Neu¹,

Goff²,

Runde³

2005

Encyclopedia of Inorganic Chemistry

View full text Add to dashboard Cite

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.

show abstract

Plutonium(III) oxidation under α-irradiation in nitric acid solutions

Cited by 15 publications

References 1 publication

Plutonium and Americium Alpha Radiolysis of Nitric Acid Solutions

Plutonium and Americium Alpha Radiolysis of Nitric Acid Solutions

Model for predicting hydroxylamine nitrate stability in plutonium process solutions

Plutonium: Radionuclides

Contact Info

Product

Resources

About