Phase Behavior of the Ternary NaCl-PuCl3-Pu Molten Salt

Karlsson, Toni Y.; Adkins, Cynthia A.; Gakhar, Ruchi; Newman, James R.; Monk, Steven L.; Warmann, Stephen A.

doi:10.7733/jnfcwt.2023.011

Phase Behavior of the Ternary NaCl-PuCl₃-Pu Molten Salt

Journal Article · Thu Mar 30 00:00:00 EDT 2023 · Journal of Nuclear Fuel Cycle and Waste Technology

DOI:https://doi.org/10.7733/jnfcwt.2023.011· OSTI ID:1984023

^[1]; ^[1]; ^[1]; Newman, James R. ^[1]; Monk, Steven L. ^[1]; ^[1]

Idaho National Laboratory (INL), Idaho Falls, ID (United States)

There is a gap in our understanding of the behavior of fused and molten fuel salts containing unavoidable contamination, such as those due to fabrication, handling, or storage. Therefore, this work used calorimetry to investigate the change in liquidus temperature of PuCl₃, having an unknown purity and that had been in storage for several decades. Further research was performed by additions of NaCl, making several compositions within the binary system, and summarizing the resulting changes, if any, to the phase diagram. The melting temperature of the PuCl₃ was determined to be 746.5°C, approximately 20°C lower than literature reported values, most likely due to an excess of Pu metal in the PuCl₃ either due to the presence of metallic plutonium remaining from incomplete chlorination or due to the solubility of Pu in PuCl₃. From the melting temperature, it was determined that the PuCl₃ contained between 5.9 to 6.2mol% Pu metal. Analysis of the NaCl-PuCl₃ samples showed that using the Pu rich PuCl₃ resulted in significant changes to the NaCl-PuCl₃ phase diagram. Most notably an unreported phase transition occurring at approximately 406°C and a new eutectic composition of 52.7mol% NaCl–38.7mol% PuCl₃–2.5mol% Pu which melted at 449.3°C. Additionally, an increase in the liquidus temperatures was seen for NaCl rich compositions while lower liquidus temperatures were seen for PuCl₃ rich compositions. It can therefore be concluded that changes will occur in the NaCl-PuCl₃ binary system when using PuCl₃ with excess Pu metal. However, melting temperature analysis can provide valuable insight into the composition of the PuCl₃ and therefore the NaCl-PuCl₃ system.

Research Organization:: Idaho National Laboratory (INL), Idaho Falls, ID (United States)

Sponsoring Organization:: USDOE Office of Nuclear Energy (NE)

Grant/Contract Number:: AC07-05ID14517

OSTI ID:: 1984023

Report Number(s):: INL/JOU-22-68187-Rev000

Journal Information:: Journal of Nuclear Fuel Cycle and Waste Technology, Journal Name: Journal of Nuclear Fuel Cycle and Waste Technology Journal Issue: 1 Vol. 21; ISSN 1738-1894

Publisher:: Korean Radioactive Waste SocietyCopyright Statement

Country of Publication:: United States

Language:: English

References (8)

The PuPuCl3 system Johnson, K. W. R.; Leary, J. A. Journal of Inorganic and Nuclear Chemistry, Vol. 26, Issue 1 https://doi.org/10.1016/0022-1902(64)80236-0	journal	January 1964
Partial phase diagram of the PuCl3PuOCl system Reavis, J. G.; Leary, J. A. Journal of Inorganic and Nuclear Chemistry, Vol. 28, Issue 5 https://doi.org/10.1016/0022-1902(66)80446-3	journal	May 1966
Crystallographic studies of some transuranic trihalides: 239PuCl3, 244CmBr3, 249BkBr3 and 249CfBr3 Burns, John H.; Peterson, J. R.; Stevenson, J. N. Journal of Inorganic and Nuclear Chemistry, Vol. 37, Issue 3 https://doi.org/10.1016/0022-1902(75)80532-X	journal	March 1975
Phase Equilibria in the Binary Systems PuCl ₂ –NaCl and PuCl ₂ –LiCl Bjorklund, C. W.; Reavis, J. G.; Leary, J. A. The Journal of Physical Chemistry, Vol. 63, Issue 10 https://doi.org/10.1021/j150580a049	journal	October 1959
The Vapor Pressure of Plutonium Halides Phipps, T. E.; Sears, G. W.; Seifert, R. L. The Journal of Chemical Physics, Vol. 18, Issue 5 https://doi.org/10.1063/1.1747733	journal	May 1950
Thermodynamics of lanthanide halides and application to high-temperature processes Gaune-Escard, Marcelle Scandinavian Journal of Metallurgy, Vol. 34, Issue 6 https://doi.org/10.1111/j.1600-0692.2005.00757.x	journal	December 2005
Cl-Pu (chlorine-plutonium) Okamoto, H. Journal of Phase Equilibria, Vol. 20, Issue 5 https://doi.org/10.1361/105497199770340806	journal	September 1999
National Low-Level Waste Management Program radionuclide report series. Volume 2, Niobium-94 Adams, J. P.; Carboneau, M. L. https://doi.org/10.2172/137362	report	April 1995

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