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Title: Carbothermic Synthesis of ~820- m UN Kernels. Investigation of Process Variables

Abstract

This report details the continued investigation of process variables involved in converting sol-gel-derived, urainia-carbon microspheres to ~820-μm-dia. UN fuel kernels in flow-through, vertical refractory-metal crucibles at temperatures up to 2123 K. Experiments included calcining of air-dried UO3-H2O-C microspheres in Ar and H2-containing gases, conversion of the resulting UO2-C kernels to dense UO2:2UC in the same gases and vacuum, and its conversion in N2 to in UC1-xNx. The thermodynamics of the relevant reactions were applied extensively to interpret and control the process variables. Producing the precursor UO2:2UC kernel of ~96% theoretical density was required, but its subsequent conversion to UC1-xNx at 2123 K was not accompanied by sintering and resulted in ~83-86% of theoretical density. Decreasing the UC1-xNx kernel carbide component via HCN evolution was shown to be quantitatively consistent with present and past experiments and the only useful application of H2 in the entire process.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1254083
Report Number(s):
ORNL/TM-2015/301
AF5810000; NEAF278
DOE Contract Number:  
AC05-00OR22725
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE

Citation Formats

Lindemer, Terrence, Silva, Chinthaka M, Henry, Jr, John James, McMurray, Jake W, Jolly, Brian C, Hunt, Rodney Dale, and Terrani, Kurt A. Carbothermic Synthesis of ~820- m UN Kernels. Investigation of Process Variables. United States: N. p., 2015. Web. doi:10.2172/1254083.
Lindemer, Terrence, Silva, Chinthaka M, Henry, Jr, John James, McMurray, Jake W, Jolly, Brian C, Hunt, Rodney Dale, & Terrani, Kurt A. Carbothermic Synthesis of ~820- m UN Kernels. Investigation of Process Variables. United States. https://doi.org/10.2172/1254083
Lindemer, Terrence, Silva, Chinthaka M, Henry, Jr, John James, McMurray, Jake W, Jolly, Brian C, Hunt, Rodney Dale, and Terrani, Kurt A. 2015. "Carbothermic Synthesis of ~820- m UN Kernels. Investigation of Process Variables". United States. https://doi.org/10.2172/1254083. https://www.osti.gov/servlets/purl/1254083.
@article{osti_1254083,
title = {Carbothermic Synthesis of ~820- m UN Kernels. Investigation of Process Variables},
author = {Lindemer, Terrence and Silva, Chinthaka M and Henry, Jr, John James and McMurray, Jake W and Jolly, Brian C and Hunt, Rodney Dale and Terrani, Kurt A},
abstractNote = {This report details the continued investigation of process variables involved in converting sol-gel-derived, urainia-carbon microspheres to ~820-μm-dia. UN fuel kernels in flow-through, vertical refractory-metal crucibles at temperatures up to 2123 K. Experiments included calcining of air-dried UO3-H2O-C microspheres in Ar and H2-containing gases, conversion of the resulting UO2-C kernels to dense UO2:2UC in the same gases and vacuum, and its conversion in N2 to in UC1-xNx. The thermodynamics of the relevant reactions were applied extensively to interpret and control the process variables. Producing the precursor UO2:2UC kernel of ~96% theoretical density was required, but its subsequent conversion to UC1-xNx at 2123 K was not accompanied by sintering and resulted in ~83-86% of theoretical density. Decreasing the UC1-xNx kernel carbide component via HCN evolution was shown to be quantitatively consistent with present and past experiments and the only useful application of H2 in the entire process.},
doi = {10.2172/1254083},
url = {https://www.osti.gov/biblio/1254083}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jun 01 00:00:00 EDT 2015},
month = {Mon Jun 01 00:00:00 EDT 2015}
}