Gas-phase thermal dissociation of uranium hexafluoride: Investigation by the technique of laser-powered homogeneous pyrolysis
In the gas-phase, uranium hexafluoride decomposes thermally in a quasi-unimolecular reaction to yield uranium pentafluoride and atomic fluorine. We have investigated this reaction using the relatively new technique of laser-powered homogeneous pyrolysis, in which a megawatt infrared laser is used to generate short pulses of high gas temperatures under strictly homogeneous conditions. In our investigation, SiF/sub 4/ is used as the sensitizer to absorb energy from a pulsed CO/sub 2/ laser and to transfer this energy by collisions with the reactant gas. Ethyl chloride is used as an external standard ''thermometer'' gas to permit estimation of the unimolecular reaction rate constants by a relative rate approach. When UF/sub 6/ is the reactant, CF/sub 3/Cl is used as reagent to trap atomic fluorine reaction product, forming CF/sub 4/ as a stable indicator which is easily detected by infrared spectroscopy. Using these techniques, we estimate the UF/sub 6/ unimolecular reaction rate constant near the high-pressure limit. In the Appendix, we describe a computer program, written for the IBM PC, which predicts unimolecular rate constants based on the Rice-Ramsperger-Kassel theory. Parameterization of the theoretical model is discussed, and recommendations are made for ''appropriate'' input parameters for use in predicting the gas-phase unimolecular reaction rate for UF/sub 6/ as a function of temperature and gas composition and total pressure. 85 refs., 17 figs., 14 tabs.
- Research Organization:
- Oak Ridge Gaseous Diffusion Plant (K-25), Oak Ridge, TN (United States)
- DOE Contract Number:
- AC05-84OT21400; AC05-84OR21400; W-7405-ENG-36
- OSTI ID:
- 6630899
- Report Number(s):
- K/PS-1187; ON: DE87008955
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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36 MATERIALS SCIENCE
URANIUM HEXAFLUORIDE
THERMAL DEGRADATION
CHEMICAL REACTION KINETICS
INFRARED SPECTRA
URANIUM PENTAFLUORIDE
ACTINIDE COMPOUNDS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
KINETICS
REACTION KINETICS
SPECTRA
URANIUM COMPOUNDS
URANIUM FLUORIDES
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