Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Hot Hydrogen Testing of W-Coated UN Kernels in a Mo30W Matrix

Journal Article · · Nuclear Science and Engineering
Ceramic uranium mononitride (UN) is being considered as a reactor fuel for nuclear thermal propulsion. To avoid or reduce the dissociation of UN at the high temperatures needed, embedding it in a metallic matrix (cermet) has been proposed. To assess the viability of this concept, hot hydrogen testing of tungsten-coated UN kernels embedded in a Mo-30 wt% W (Mo30W) alloy matrix has been performed at temperatures from 1800°C to 2300°C. Both the isolated kernels and kernels consolidated by spark plasma sintering in the Mo30W matrix were tested. In addition to direct observations and mass loss measurements, the samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) after each run. The decomposition of UN started at 1800°C despite the coating and matrix, and increased at 2000°C. Uranium seeped through the tungsten grain boundaries of the coating at all temperatures. The consolidated sample expanded irregularly at 2000°C through the formation of voids, and SEM/EDS analysis showed uranium-containing veins in the matrix consisting of U2Mo according to the XRD data. The observed pore generation at 2000°C was explained by the formation of water vapor from residual oxides and diffused hydrogen. At 2200°C and above, both the kernels and the consolidated samples melted through the formation of uranium or low–melting point uranium-molybdenum alloys.
Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
National Aeronautics and Space Administration (NASA); USDOE
Grant/Contract Number:
89233218CNA000001
OSTI ID:
2340868
Report Number(s):
LA-UR--23-20007
Journal Information:
Nuclear Science and Engineering, Journal Name: Nuclear Science and Engineering Journal Issue: 1 Vol. 199; ISSN 0029-5639
Publisher:
Taylor & FrancisCopyright Statement
Country of Publication:
United States
Language:
English

References (35)

Critical Composition of Antiferromagnetic Ordering in UNxC1−x journal September 1983
The N-W (nitrogen-tungsten) system journal August 1989
Spectral Emissivities and Emissivity X-Points of Pure Molybdenum and Tungsten journal July 2005
Hydrogen Embrittlement of Metals: A Primer for the Failure Analyst journal May 2008
U-W (Uranium-Tungsten) journal May 2009
Mo-U (Molybdenum-Uranium) journal July 2012
Review and Preliminary Investigation into Fuel Loss from Cermets Composed of Uranium Nitride and a Molybdenum-Tungsten Alloy for Nuclear Thermal Propulsion Using Mesoscale Simulations journal September 2021
Reactions of uranium carbonitrides and uranium nitride with aqueous solutions of hydrochloric, sulfuric, and nitric acids journal September 1970
Thermochemische und technologische untersuchungen im system uranmononitrid-kohlenstoff journal February 1968
Phase relations and thermodynamic properties of the uranium-nitrogen system journal May 1974
Investigations on uranium carbonitrides (I) journal June 1975
Vaporization of uranium-carbon-nitrogen system journal February 1976
Investigations on uranium carbonitrides journal April 1980
Effect of liquid uranium on tungsten foils up to 1350°C journal November 1988
Progressive dissolution of molybdenum foils in liquid uranium at 1160°C journal December 1988
Material property correlations for uranium mononitride journal May 1990
Material property correlations for uranium mononitride journal May 1990
Vapour pressures of uranium and uranium nitride over UN(s) journal February 1992
The uranium monocarbide-uranium mononitride system journal June 1959
Advances in fuel fabrication book March 2020
Thermodynamic and Thermophysical Properties of the Actinide Nitrides book August 2020
Thermal conductivity of UC1 − xNx from 100 to 1000 °K journal January 1974
Thermal stability investigation technique for uranium nitride journal January 2016
A review of uranium corrosion by hydrogen and the formation of uranium hydride journal May 2018
Consolidation behavior of Mo30W alloy using spark plasma sintering journal April 2022
Literature review of thermal and radiation performance parameters for high-temperature, uranium dioxide fueled cermet materials journal July 2007
Thermophysical properties of U2Mo intermetallic journal January 2012
Uranium migration in spark plasma sintered W/UO2 CERMETS journal March 2018
Microstructural evolution of Mo-UO2 cermets under high temperature hydrogen environments journal September 2020
The Powder Diffraction File: a quality materials characterization database journal November 2019
Space Nuclear Propulsion Fuel and Moderator Development Plan Conceptual Testing Reference Design journal April 2021
On the Formation of UC1-xN1-x journal April 1964
Model for the Calculation of the Dissociation Rate of Nitride Fuel at High Temperatures journal March 2020
Hot Hydrogen Testing of W-Coated UN Kernels for Nuclear Thermal Propulsion conference January 2022
Hydrogen Reactions with Graphite Materials at High Temperatures and Pressures journal March 1968

Similar Records

Formation and Consolidation of UN Nanostructures in U-Mo Fuel via Mechanical Alloying and Spark Plasma Sintering
Thesis/Dissertation · Thu Apr 27 00:00:00 EDT 2023 · OSTI ID:1983625

Hot explosive compaction of Mo-Ti alloys
Journal Article · Wed Sep 01 00:00:00 EDT 1999 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science · OSTI ID:684465

Evaluation of plasma sprayed crucible coatings for melt processing copper-refractory metal alloys
Conference · Tue Dec 31 23:00:00 EST 1991 · OSTI ID:5467089