Thermodynamic properties for rare earths and americium in pyropartitioning process solvents

Journal Article · Thu Jul 01 04:00:00 EDT 1999 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1391974· OSTI ID:680051

Fusselman, S P; Roy, J J; Grimmett, D L ^[1]

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1. Boeing Co., Canoga Park, CA (United States). Rocketdyne Propulsion and Power; and others

The design of a molten metal-molten salt based chemical and electrochemical process for separation of actinides from plutonium-uranium extraction waste requires a consistent set of thermodynamic properties for the actinides and rare earths present in nuclear waste. Standard potential data for Y, La, Ce, Pr, and Gd in molten LiCl-KCl were obtained. Americium data obtained were standard potentials in molten LiCl-KCl and activity coefficients for Cd and Bi. Data were obtained between 400 and 500 C. Results for the rare earth chlorides using an improved experimental technique were consistent with theory, with standard free energy of formation values somewhat more negative than those found in the literature. Special attention was given to Am in the LiCl-KCl/Cd system because it can exist as the +2 and/or +3 ion in this system. Americium ions existed only as the +3 ion in LiCl-KCl/Bi. Standard electrochemical potentials for Am/Am{sup +2} in LiCl-KCl eutectic at 400, 450, and 500 C were {minus}2.893, {minus}2.853, and {minus}2.838 V, respectively, relative to Cl{sup 2}/Cl{sup {minus}}. Standard electrochemical potentials vs. Cl{sub 2}/Cl{sup {minus}} for Am/Am{sup +3} in LiCl-KCl eutectic were {minus}2.83 V at 450 C and {minus}2.78 V at 500 C. Activity coefficients for Am in molten Cd were 1 {times} 10{sup {minus}5} and 8 {times} 10{sup {minus}5} at 450 and 500 C.

• Sponsoring Organization: USDOE, Washington, DC (United States); Central Research Inst. of Electric Power Industry, Tokyo (Japan); Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 680051
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 7 Vol. 146; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
36 MATERIALS SCIENCE
AMERICIUM
CERIUM
GADOLINIUM
LANTHANUM
MOLTEN SALT WASTE GASIFICATION PROCESS
PRASEODYMIUM
RADIOACTIVE WASTE PROCESSING
THERMODYNAMIC PROPERTIES
YTTRIUM