Document Type

Article

Publication Date

10-1-2010

Abstract

The reaction kinetics of ZrN and HfN immersed in a quaternary salt of composition of 28.5% LiCl-36.3% KCl- 29.4% NaCl- 5.8% UCl3 (in weight percent) were assessed. Coupons of ZrN and HfN were exposed to the quaternary salt at 525 to 900°C for 4 to 485 hours. The reaction kinetics of the salt-refractory interactions were assessed through physical and microstructural characterization including scanning electron microscopy, x-ray diffraction and mass spectrometry. The results indicated that ZrN and HfN lose weight under all conditions investigated. While multiple mechanisms were evident, it is proposed that dissolution and oxidation were the dominant reactions that influence the weight loss. For the overall reaction, negative apparent activation energy values of -46 and -28 kJ/mol were observed in ZrN and HfN, respectively. This seemingly anomalous activation energy was associated with the simultaneous occurrence of electrochemical dissolution and surface oxide formation.

Comments

NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. The definitive version has been published in Journal of Nuclear Materials, Oct. 2010, Vol. 405 Issue 3. DOI: 10.1016/j.jnucmat.2010.08.015