Structural features of early fuel cycle taggant incorporation for intentional nuclear forensics
To develop strategies for incorporating transition metal taggants (Fe, Cr, and Ni) into oxide fuels and to understand how these taggant candidates persist through early fuel cycle processes, synthetic procedures are modified from established production routes to yield intentionally tagged early fuel cycle intermediates including uranyl nitrate hexahydrate (UNH, UO2(NO3)2·6H2O), uranyl peroxide tetrahydrate (studtite, UO2O2·4H2O), and uranyl peroxide dihydrate (metastudtite, UO2O2·2H2O). First, Fe, Cr, and Ni nitrate solutions are introduced to an aqueous solution of UNH followed by precipitation to produce tagged UNH. Then, studtite is precipitated from UNH followed by dehydration to metastudtite. Structural influences of taggant incorporation within all synthesized phases are investigated using powder X-ray diffraction (PXRD) and Raman spectroscopy to provide insight into crystallographic modifications resulting from the addition of tags to these early fuel cycle materials and elucidate the chemical form of taggants introduced at these stages. The possibility of segregation of taggant species into discrete phases within U matrices was examined using scanning electron microscopy with energy dispersive X-ray spectroscopy. Taggant concentrations in solid-phase materials were determined using inductively coupled plasma-optical emission spectroscopy. Observations from Raman spectroscopy and PXRD indicate that introducing transition metal tags during uranyl nitrate precipitation results in potential impurity phase segregation in UNH, but transition metal incorporation is suggested by results for tagged uranyl peroxide materials. Further, results from this study will inform strategies for optimizing taggant incorporation in UO2.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 2217722
- Journal Information:
- Journal of Nuclear Materials, Vol. 588, Issue 1; ISSN 0022-3115
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dehydration of the Uranyl Peroxide Studtite, [UO2(η2-O2)(H2O)2]·2H2O, Affords a Drastic Change in the Electronic Structure: A Combined X-ray Spectroscopic and Theoretical Analysis
In Situ Liquid Cell Transmission Electron Microscopy Study of Studtite Particle Formation and Growth via Electron Beam Radiolysis