Uranium isotope exchange between gaseous UF{sub 6} and solid UF{sub 5}

Book · Thu Aug 01 04:00:00 EDT 1996

OSTI ID:268073

Yato, Yumio; Kishimoto, Yoichiro; Sasao, Nobuyuki ^[1]; Suto, Osamu; Funasaka, Hideyuki ^[2]

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1. Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)
2. Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Nuclear Fuel Technology Development Div.

Based on a collision model, a new rate equation is derived for uranium isotope exchange between gaseous UF{sub 6} and solid UF{sub 5} by considering the number of UF{sub 5} molecules on the solid surface to be dependent on time. The reaction parameters included in the equation are determined from the experimental data and compared with the previous ones. A remarkable agreement is found between the particle sizes of UF{sub 5} estimated from the reaction parameter and from the direct observation with an electron microscope. The rate equation given in this work fully satisfies the related mass conservation and furthermore includes explicitly the terms related to the UF{sub 6} density and the mean size of UF{sub 5} particles, both of which are considered to cause an important effect on the reaction. This remarkable feature facilitates the simulation studies on this reaction under various conditions. The long term behavior of a simulated exchange reaction is studied under the condition considered to be close to that in a recovery zone of the MLIS process. The result indicates that the reaction is virtually limited to the solid surface under this conditions and thus the depletion of {sup 235}UF{sub 5} concentration averaged over the whole UF{sub 5} particles is not significant even after 200 h of the exchange reaction.

• OSTI ID: 268073
• Report Number(s): CONF-960306--; ISBN 0-7918-1226-X
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
40 CHEMISTRY
DECOMPOSITION
DEPLETED URANIUM
EXPERIMENTAL DATA
INFRARED RADIATION
ISOTOPE ENRICHED MATERIALS
ISOTOPIC EXCHANGE
KINETIC EQUATIONS
LASER ISOTOPE SEPARATION
PHOTOLYSIS
THEORETICAL DATA
URANIUM 235
URANIUM HEXAFLUORIDE
URANIUM PENTAFLUORIDE