Thermodynamics of neptunium(V) fluoride and sulfate at elevatedtemperatures

Conference · Tue Oct 31 04:00:00 EST 2006

OSTI ID:919372

Rao, Linfeng; Tian, Guoxin; Xia, Yuanxian; Friese, Judah I

Complexation of neptunium(V) with fluoride and sulfate at elevated temperatures was studied by microcalorimetry. Thermodynamic parameters, including the equilibrium constants and enthalpy of protonation of fluoride and sulfate, and the enthalpy of complexation between Np(V) and fluoride and sulfate at 25 - 70 C were determined. Results show that the complexation of Np(V) with fluoride and sulfate is endothermic and that the complexation is enhanced by the increase in temperature - a three-fold increase in the stability constants of NpO{sub 2}F(aq) and NpO{sub 2}SO{sub 4}{sup -} as the temperature is increased from 25 to 70 C.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE. Office of Civilian Radioactive Waste Management.Waste Management System
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 919372
• Report Number(s): LBNL--59805; BnR: DF0961000
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ENTHALPY
FLUORIDES
HIGH-LEVEL RADIOACTIVE WASTES
MANAGEMENT
STABILITY
SULFATES
THERMODYNAMICS