Erik Paul Luther

Nanoporous Metal Foams

Nanoporous metal foams (NMFs) have been a long sought-after class of materials in the quest for high-surface-area conductive and catalytic materials. Herein we present an overview of newly developed synthetic strategies for producing NMFs along with an in-depth discussion of combustion synthesis as a versatile and scalable approach for the preparation of nanoporous, nanostructured metal foams. Current applications of NMFs prepared using combustion synthesis are also presented including hydrogen storage and catalysis.

Update on Fabrication of Extrusions for TREAT Trade Study

This supplemental report describes fuel fabrication efforts conducted for the Idaho National Laboratory Trade Study for the TREAT Conversion project that is exploring the replacement of the HEU (Highly Enriched Uranium) fuel core of the TREAT reactor with LEU (Low Enriched Uranium) fuel. Previous reports have documented fabrication of fuel by the “upgrade” process developed at Los Alamos National Laboratory. These experiments supplement an earlier report that describes efforts to increase the graphite content of extruded fuel and minimize cracking.

Evaluation of LANL Capabilities for Fabrication of TREAT Conversion Fuel

This report estimates costs and schedule associated with scale up and fabrication of a low-enriched uranium (LEU) core for the Transient Reactor Test Facility (TREAT) reactor. This study considers facilities available at Los Alamos National Laboratory, facility upgrades, equipment, installation and staffing costs. Not included are costs associated with raw materials and off-site shipping. These estimates are considered a rough of magnitude. At this time, no specifications for the LEU core have been made and the final schedule needed by the national program. The estimate range (+/-100%) reflects this large uncertainty and is subject to change as the project scope becomes more defined.

Nuclear material identification using resonant ultrasound spectroscopy

Resonant ultrasound spectroscopy (RUS) is a well-established method for determination of the full tensor of elastic moduli of a solid sample in a single frequency sweep. The elastic moduli, together with density, can provide information related to materials fabrication processes, providing a unique signature, or fingerprint, of a material. The goal of this study was to provide forensics for nuclear materials in solid ceramic or metallic form, including composition. The premise of this study was that it is really difficult to find two materials whose density and shear and /or bulk modulus match. We used RUS to determine the bulk and shear modulus for a total of 27 samples. The samples consisted of depleted uranium oxide (MOX) with different doping of Ce, Pu, and Nd oxides, and different methods of fabrication. They were in form of cylinders with flat and parallel faces. Two-dimensional and three-dimensional spaces were investigated, using shear modulus, bulk modulus, and density as variables. The densities...

Energetic Decomposition of High-Nitrogen Metal Complexes and the Formation of Low-Density Nano-Structured Metal Monoliths

Metal complexes of the energetic high-nitrogen ligand, bistetrazole amine (BTA) were ignited in inert environments and their decomposition characteristics were determined. These molecules were found to have the unique properties of a comparatively slow burning rate with very little pressure dependency, unlike most energetic, metal-containing molecules which tend to detonate, rather than burn steadily. This process resulted in unprecedented ultra-low-density, nano-structured, transition metal monoliths, useful as a self-propagating combustion synthesis technique. The resulting nanostructured metal monolithic foams formed in the post flame-front dynamic assembly have remarkably low densities down to 0.011 g cm -3 and extremely high surface areas as high as 270 m 2 g -1 . In this work we discuss primary the production of iron monoliths, however have produced monolithic nano-porous metal foams via this method with cobalt, copper and silver metals as well. We expect to be able to apply this to many other metals and to be able to tailor the resulting structure significantly.