Organophosphorus-Modified Lanthanide Nitrates as Potential Actinide Oxide Aerosol Surrogates.

In search of suitable simulants for aerosol uranium waste products from Plutonium Uranium Redox Extraction (PUREX) process burns, a series of lanthanide nitrate hydrates ([Ln(NO)·HO]) were dissolved in the presence of tributylphosphate (O═P(O(CH)CH)) referred to as TBP) in kerosene or triphenylphosphate (O═P(O(CH) referred to as TPhP) in acetone. The crystal structure of the TPhP derivatives of the lanthanide nitrate series and uranium nitrate were solved as [Ln(κNO)(TPhP)] ( = , , , , , , , , , , , , , ) and [U(O)(κNO)(TPhP)] (), respectively. The lanthanide-TBP, , and were further characterized using FTIR spectroscopy, P NMR spectroscopy, thermogravimetric analysis, and X-ray fluorescence spectroscopy. Further, thermal treatment of the lanthanide-TBP, , and using a box furnace to mimic pyrolysis conditions was found by PXRD analyses to generate a phosphate phase [LnPO or UPO) for all systems. The resultant nuclear waste fire contaminant particulates will impact both aerosol transport and toxicity assessments.