Stony Brook University2015-01-06 3:46 PM

Molten uranium dioxide structure and dynamics

Abstract


Uranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and leakage of radioactive UO2 as it corrodes through its zirconium cladding and steel containment. Yet, the very high temperatures (>3140 kelvin) and chemical reactivity of molten UO2 have prevented structural studies. In this work, we combine laser heating, sample levitation, and synchrotron x-rays to obtain pair distribution function measurements of hot solid and molten UO2. The hot solid shows a substantial increase in oxygen disorder around the lambda transition (2670 K) but negligible U-O coordination change. On melting, the average U-O coordination drops from 8 to 6.7 ± 0.5. Molecular dynamics models refined to this structure predict higher U-U mobility than 8-coordinated melts.


Full Article:

http://www.sciencemag.org/content/346/6212/984.abstract

KEYWORDS

SHARE & LIKE

COMMENTS

ABOUT THE AUTHOR

Stony Brook University

0 Following 0 Fans 0 Projects 3 Articles

SIMILAR ARTICLES

Keywords:Emotion;empathy;highly sensitive person;magnetic resonance imaging;mirror neurons;sensory processing sensitivityAbstractBackgroundTheory an

Read More

Abstract Microraptorines are a group of predatory dromaeosaurid theropod dinosaurs with aerodynamic capacity. These close relatives of birds are esse

Read More

AbstractUranium dioxide (UO2) is the major nuclear fuel component of fission power reactors. A key concern during severe accidents is the melting and l

Read More