Solubility of plutonium in MgCl2 and CaCl2 solutions in contact with metallic iron
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Marcus Altmaier
Abstract
The solubility of Pu(IV) hydrous oxide is studied at 22±2 °C under Ar atmosphere in 0.25 and 3.5 M MgCl2 (pHc≈9) and 3.5 M CaCl2 (pHc=11–12) solutions in contact with iron powder. In alkaline 3.5–4.0 M CaCl2 ternary Ca-Pu-OH complexes are formed and the solubility of PuO2·xH2O(s) increases from about 10-10 M at pHc=11 to 10-8–10-7 M at pHc=12, both in the presence and absence of Fe powder. In the presence of iron the aqueous speciation is dominated by Pu(III) at pHc<10 and by Pu(IV) complexes at pHc>10. In the absence of reducing agents the aqueous speciation is dominated by Pu(V), with significant contributions of Pu(IV) complexes at pHc>10. The effect of ternary Ca-Pu(III,IV,V)-OH complexes in alkaline CaCl2 solutions can be described by assuming complex stoichiometries and experimental data from the oxidation state analogs Cm(III)/Nd(III), Th(IV) and Np(V). The ion interaction Pitzer approach is used for model calculations.
© by Oldenbourg Wissenschaftsverlag, München, Germany
Artikel in diesem Heft
- Preface
- Solubility of Pu and rare-earths in LiCl-Li2O melt
- Solubility of plutonium in MgCl2 and CaCl2 solutions in contact with metallic iron
- Complex formation and solubility of Pu(IV) with malonic and succinic acids
- New insights in the formation processes of Pu(IV) colloids
- Redox equilibria of Pu4+/Pu3+ and PuO22+/Pu4+ couples in molten NaCl-CsCl eutectic as measured by absorption spectrophotometry
- In search of an optimum plutonium density measurement fluid
- Some aspects of neptunium acetohydroxamic acid chemistry under acidic conditions
- Excitation spectra of near-infrared photoluminescence from Np(VI) in Cs2U(Np)O2Cl4
- Study of reaction of curium oxy-compound formation in molten chlorides
- Extraction behaviour of actinides and lanthanides in TALSPEAK, TRUEX and NPEX processes of UREX+
- Effect of oxide ions on separation factors of actinides from lanthanides in reductive extraction
- Solid phase precipitates in (Zr,Th)-OH-(oxalate, malonate) ternary aqueous system
- The adsorption of ammonia on polycrystalline thorium
- Formation and stability of actinide oxides: a valence band photoemission study
- Plutonium traces in atmospheric precipitation and in aerosols from Krakow and Bialystok
- Plutonium in the environment: key factors related to impact assessment in case of an accidental atmospheric release
- Unveiling the history of seized plutonium through nuclear forensic investigations
Artikel in diesem Heft
- Preface
- Solubility of Pu and rare-earths in LiCl-Li2O melt
- Solubility of plutonium in MgCl2 and CaCl2 solutions in contact with metallic iron
- Complex formation and solubility of Pu(IV) with malonic and succinic acids
- New insights in the formation processes of Pu(IV) colloids
- Redox equilibria of Pu4+/Pu3+ and PuO22+/Pu4+ couples in molten NaCl-CsCl eutectic as measured by absorption spectrophotometry
- In search of an optimum plutonium density measurement fluid
- Some aspects of neptunium acetohydroxamic acid chemistry under acidic conditions
- Excitation spectra of near-infrared photoluminescence from Np(VI) in Cs2U(Np)O2Cl4
- Study of reaction of curium oxy-compound formation in molten chlorides
- Extraction behaviour of actinides and lanthanides in TALSPEAK, TRUEX and NPEX processes of UREX+
- Effect of oxide ions on separation factors of actinides from lanthanides in reductive extraction
- Solid phase precipitates in (Zr,Th)-OH-(oxalate, malonate) ternary aqueous system
- The adsorption of ammonia on polycrystalline thorium
- Formation and stability of actinide oxides: a valence band photoemission study
- Plutonium traces in atmospheric precipitation and in aerosols from Krakow and Bialystok
- Plutonium in the environment: key factors related to impact assessment in case of an accidental atmospheric release
- Unveiling the history of seized plutonium through nuclear forensic investigations
