Kinetic study of the thermal decomposition of uranium metaphosphate, U(PO 3 ) 4 , into uranium pyrophosphate, UP 2 O 7

Yang, Hee-Chul; Kim, Hyung-Ju; Lee, Siyoung; Yang, In-Hwan; Chung, Dong-Yong

doi:10.1016/j.jnucmat.2017.04.002

Cited by 3 publications

(1 citation statement)

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“…Stable phosphate phases noted for uranium favor the countercation groups, such as the Autunite group of minerals (M 3 n ( n )+ [(UO 2 )(PO 4 )] 2 · x H 2 O) (M = Ca, Na) or the Cs[UO 2 ) x (HPO 3 ) y (H 2 O) z ] family of materials. It is of note that metaphosphate (U(PO 3 ) 4 ) has been shown to decompose into the pyrophosphate (U(P 2 O 7 ), which may explain the variation in the phases noted, as the LnPO 4 materials are reportedly stable to >900 °C.…”

Section: Results and Discussionmentioning

confidence: 99%

Organophosphorus-Modified Lanthanide Nitrates as Potential Actinide Oxide Aerosol Surrogates

et al. 2020

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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(κ 2 -NO3)3·nH2O]) were dissolved in the presence of tributylphosphate (OP(O(CH2)3CH3)3) referred to as TBP) in kerosene or triphenylphosphate (OP(O(C6H5) 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(κ2 -NO3)3(TPhP)3] (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) and [U(O)2(κ2 -NO3)2(TPhP)2] (U), respectively. The lanthanide-TBP, Ln, and U were further characterized using FTIR spectroscopy, 31P NMR spectroscopy, thermogravimetric analysis, and X-ray fluorescence spectroscopy. Further, thermal treatment of the lanthanide-TBP, Ln, and U using a box furnace to mimic pyrolysis conditions was found by PXRD analyses to generate a phosphate phase [LnP3O9 or UP2O7) for all systems. The resultant nuclear waste fire contaminant particulates will impact both aerosol transport and toxicity assessments.

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Section: Results and Discussionmentioning

confidence: 99%