Oxidative dissolution of plutonium dioxide in nitric acid in the presence of ozone. I. Reaction of plutonium dixode with cerium (IV) in nitric acid solutions

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Radiochemistry

OSTI ID:174274

Ivanov, Yu E; Nikitina, G P ^[1]

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1. Khlopin Radium Inst., St. Petersburg (Russian Federation)

In this work, the authors report the results of a study of plutonium dioxide oxidation with cerium(IV) in 1-4 M solutions of nitric acid, containing 2 x 10{sup {minus}3}-4 x 10{sup {minus}2} M of Ce(IV) and 1 x 10{sup {minus}3}-2x10{sup {minus}2} mol of PuO{sub 2} per liter of the solvent. The initial rate of dissolution of plutonium dioxide follows the equation (-d(PuO{sub 2})/d{tau}){sub tau}{ge}o = K{sub eff}(PuO{sub 2})(Ce(IV)){sub 0} = K{sup {prime}}{sub eff}S{sub PuO{sub 2}}(Ce(IV)){sub O}. The thermodynamic activation parameters of this process are evaluated as {delta}H{sub 298} = 54.4 {plus_minus}1.6 kJ mol{sup {minus}1}, {delta}G{sup No.}{sub 298} = 94.6{plus_minus} 0.8 kJ mol{sup {minus}1}, and {delta}S{sup No.}{sub 298} = -134{plus_minus}8 J mol{sup {minus}1} K{sup {minus}1}. A probable mechanism of the reaction of Ce(IV) with PuO{sub 2} is discussed.

• OSTI ID: 174274
• Journal Information: Radiochemistry, Journal Name: Radiochemistry Journal Issue: 3 Vol. 37; ISSN RDIOEO; ISSN 1066-3622
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
40 CHEMISTRY
CERIUM
DISSOLUTION
NITRIC ACID
OZONE
PLUTONIUM DIOXIDE
REDUCTION
THERMODYNAMIC PROPERTIES