Kinetics of the high temperature oxygen exchange reaction on 238PuO2 powder

JOURNAL OF NUCLEAR MATERIALS

卷:467

Article

Whiting, Christofer E.¹  Du, Miting²  Felker, L. Kevin²  Wham, Robert M.²  Barklay, Chadwick D.¹  Kramer, Daniel P.¹ 

[1] Univ Dayton, Res Inst, Dayton, OH 45469 USA

[2] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA

关键词: Oxygen exchange;    Kinetics;    Internal chemical reaction;    Surface exchange;    Surface mobility;    Plutonium (IV) oxide;   

DOI  :  10.1016/j.jnucmat.2015.10.020

来源: Elsevier

【 摘 要 】

Oxygen exchange reactions performed on PuO2 suggest the reaction is influenced by at least three mechanisms: an internal chemical reaction, surface mobility of active species/defects, and surface exchange of gaseous oxygen with lattice oxygen. Activation energies for the surface mobility and internal chemical reaction are presented. Determining which mechanism is dominant appears to be a complex function including at least specific surface area and temperature. Thermal exposure may also impact the oxygen exchange reaction by causing reductions in the specific surface area of PuO2. Previous CeO2 surrogate studies exhibit similar behavior, confirming that CeO2 is a good qualitative surrogate for PuO2, in regards to the oxygen exchange reaction. Comparison of results presented here with previous work on the PuO2 oxygen exchange reaction allows complexities in the previous work to be explained. These explanations allowed new conclusions to be drawn, many of which confirm the conclusions presented here. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free