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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Separation and purification of Mo-99 produced from natural U 3 0 8 targets via photo-fission

The most-used medical isotope is 99m Tc (t½ = 6.0 h), which comprises over 80% of isotopes used in nuclear medicine today. It is normally derived from its transient equilibrium parent 99 Mo (t½ = 66 h). A recent surge of interest in using the more proliferation-resistant low-enriched uranium (LEU) under the American Medical Isotope Production Act (AMIPA) has presented this technical challenge: can a domestic supplier meet the estimated weekly U.S. demand of 1500 6–day Ci of 99 Mo?

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Irradiation of Sintered Mo Disks with Presence of Organic Impurities in He Gas Flow

Argonne National Laboratory (Argonne) is assisting NorthStar Medical Technologies in the development of a domestic supply of 99 Mo. Specifically, the present study focuses on the production of 99 Mo-feed solution used by the RadioGenix™ 99m Tc generator. During the target-irradiation phase of production, impurities can potentially be introduced into the feed, and can lead to disturbance of ligand- 99m Tc complexation chemistry and contamination of the final radiopharmaceutical that directly interacts with the patient. To address this issue, Argonne performed irradiations and chemical processing to identify whether the potential contamination of He flow with hydrocarbon oil during irradiation affects the radiochemical purity of the final K 2 MoO 4 (K 2 TcO 4 ) in 5M KOH solution. To mimic the conditions of real irradiation at NorthStar, Argonne used its electron linear accelerator and Van de Graaff facilities, heated the target and oil source to >800°C, and controlled oxygen in the presence of He during irradiation. Following irradiation, scanning electron microscopy (SEM) and carbon analysis (CA) were used to detect carbon contamination on the solid targets. The radiochemical purity of the dissolved targets was studied via thin-layer paper chromatography (TLC). As a result of these experiments, small regions of the surface of some irradiated disks were found to be high in carbon, but the total carbon content was still negligible in comparison to the reference sample, which had experienced no irradiation or contact with oil. The summarized results from the SEM, CA, and TLC tests lead to the conclusion that even an excess of oil and heating during irradiation do not affect the radiochemical purity of the final product.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2023

Partitioning of Radionuclides in Various Streams of the Mo-99 Purification Process

The Universal Neutron Irradiator (UNI) was designed to irradiate a small volume of uranium solution and to achieve high fission power without creating a large radionuclide (RN) inventory. The UNI system is equipped with a fully enclosed off-gas system with online hydrogen gas monitoring to prevent the production of an explosive atmosphere, as well as storage cylinders for capturing fission gases. It also includes a catalytic recombiner in the target capsule (to immediately recombine radiolytic hydrogen and oxygen gas in the system) and access ports for sampling the target solution and capsule headspace. In UNI Phase I experiments, 50 mL of uranyl sulfate solution was irradiated at 0.3–0.5 W/mL fission power using a tantalum target assembly to produce photoneutrons via irradiation with an electron beam. The purposes of the Phase I experiments were to test the efficacy of adding 200 ppm Fe 2+ to the target solution to prevent uranyl peroxide precipitation under representative irradiation conditions, and to monitor iodine speciation in the irradiated uranyl sulfate solution. The focus of the UNI Phase II experiments was to use an irradiated uranyl sulfate solution containing a mixture of fission products and monitor their distribution in various streams during the primary recovery column (titania-based column) that separates Mo-99 from uranium. Irradiations were designed to create sufficient activity for tracking their distribution in various processing streams using a combination of gamma counting and inductively coupled plasma mass spectrometry (ICP-MS) analyses. Obtained data will be used to better understand the composition of waste streams, accumulation of RN on the titania column, and identify what RNs accumulate in the uranyl sulfate solution. Furthermore, this knowledge will allow us to determine waste classifications for various streams produced during the Mo-99 purification process and develop an appropriate waste clean-up strategy.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

Baseline Hypothetical Facility for the Production of 131 I, 99 Mo, and 133 Xe from HALEU Fission Targets

The report describes the development of a hypothetical facility to produce the pharmaceutical radioisotope 131 I at an amount of 60 curies per week via the fission of a High Assay Low Enriched Uranium (HALEU) target, along with the chemical and physical processes and equipment needed to separate the 131 I and co-produced 99 Mo and 133 Xe. The hypothetical design was carried out using a 10 MWt research reactor. The irradiation calculation determined that three HALEU targets with aluminum cladding can be used to produce 60 Ci/week of 131 I, 750 Ci/week of 99 Mo and 560 Ci/week of 133 Xe. The process selected for the baseline design uses caustic dissolution of the target material with ion exchange processes to separate and purify the iodine and molybdenum. The xenon is processed using a cryogenic carbon bed separation process. Target processing occurs in seven shielded hot cells with a total footprint of 16m 2 and waste management occurs in an eight hot cell with a 2.5 m 2 footprint. Waste generated from the processing of the three targets per week would generate less than 4 shielded drums of waste annually. These hot cells would need varying levels of shielding due to the amount of fission products being handled in the unit. Hot cell facilities also require support services including QA/QC, health physics, administrative staff, operator changing room, radiological buffer areas, and waste storage. The overall facility would require a footprint of 1050 m 2 with 20.25 m 2 of shielded hot cells.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2020

Carbide Formation in Refractory Mo 15 Nb 20 Re 15 Ta 30 W 20 Alloy under a Combined High-Pressure and High-Temperature Condition

In this work, the formation of carbide with the concertation of carbon at 0.1 at.% in refractory high-entropy alloy (RHEA) Mo 15 Nb 20 Re 15 Ta 30 W 20 was studied under both ambient and high-pressure high-temperature conditions. The x-ray diffraction of dilute carbon (C)-doped RHEA under ambient pressure showed that the phases and lattice constant of RHEA were not influenced by the addition of 0.1 at.% C. In contrast, C-doped RHEA showed unexpected phase formation and transformation under combined high-pressure and high-temperature conditions by resistively employing the heated diamond anvil cell (DAC) technique. The new FCC_L1 2 phase appeared at 6 GPa and 809 °C and preserved the ambient temperature and pressure. High-pressure and high-temperature promoted the formation of carbides Ta 3 C and Nb 3 C, which are stable and may further improve the mechanical performance of the dilute C-doped alloy Mo 15 Nb 20 Re 15 Ta 30 W 20 .

36 MATERIALS SCIENCE↗
DOE OSTI2021

Y-12 NATIONAL SECURITY COMPLEX LEU-MO FEEDSTOCK FABRICATION UPDATE

The Y-12 National Security Complex (Y-12) participates in the fuel fabrication pillar of lhe National Nuclear Security Administration's (NNSA's) Office of Material Minimization and Management (M3) Office of Conversion Pillar. Y-12's primary responsibility is to establish a reliable fabrication process of low-enriched uranium-molybdenum (LEU-Mo) feedstock tor United States High Performance Research Reactors (US HPRRs). This update compares US HPRR LEU-Mo feedstock fabrication ettorts over the past several casting campaigns at Y-12 which vary in process methodologies and fabrication parameters. With recent changes to the latest feedstock casting campaign, Process Design Standard-2 (PD-STD-2). Y-12 has seen a significant decrease in isotopic uranium variability of the fuel feedstock fabricated.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Enhancing Mechanical Properties of a Medium-Entropy Alloy by Regulating Mo Addition

Some multi-principal element alloys (MPEAs), including equiatomic, single-phase CrCoNi and CrCoFeMnNi are now widely recognized for their remarkable combinations of pronounced hardening rates, high ductility, and exceptional fracture toughness at room and cryogenic temperatures. To push the limit of hardenability of the medium-entropy alloy, the strategies associated with local lattice distortion or stacking fault energy (SFE) reduction that promote complex heterogeneity and defect dynamics require further investigation. The purposes of this study are to (1) further enhance the mechanical properties of a typical medium-entropy NiCoCr with alloying Mo, and (2) understand the strengthening mechanism of a Mo-added medium-entropy alloys.

Hung, Chang-Yu↗
DOE OSTI2020

Materials Data on Mo(CO)6 by Materials Project

Mo(CO)6 is Cubic alpha N2-derived structured and crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of twenty-four formaldehyde molecules and four molybdenum(6+) molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo(WSe3)2 by Materials Project

(WSe2)2MoSe2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoSe2 sheet oriented in the (0, 0, 1) direction and two WSe2 sheets oriented in the (0, 0, 1) direction. In the MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In each WSe2 sheet, W3+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo(WS3)2 by Materials Project

(WS2)2MoS2 is Molybdenite-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction and two WS2 sheets oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six equivalent S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.42 Å. S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In each WS2 sheet, W3+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.42 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo(WS3)2 by Materials Project

(WS2)2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction and two WS2 sheets oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six equivalent S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.42 Å. S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In each WS2 sheet, W3+ is bonded to six equivalent S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.42 Å. S2- is bonded in a 3-coordinate geometry to three equivalent W3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo(NO2)2 by Materials Project

MoO4N2 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of four ammonia molecules and two MoNO4 ribbons oriented in the (1, 0, 0) direction. In each MoNO4 ribbon, Mo6+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Mo–O bond distances ranging from 1.73–2.14 Å. N1+ is bonded in a water-like geometry to two O2- atoms. There is one shorter (1.26 Å) and one longer (1.31 Å) N–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Mo6+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Mo6+ and one N1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Mo6+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Mo6+ and one N1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo(NO4)2 by Materials Project

MoO2(NO3)2 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of two MoO2(NO3)2 ribbons oriented in the (0, 1, 0) direction. Mo6+ is bonded to seven O2- atoms to form distorted corner-sharing MoO7 pentagonal bipyramids. There are a spread of Mo–O bond distances ranging from 1.71–2.24 Å. There are two inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.20–1.32 Å. In the second N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.20–1.32 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one N5+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Mo6+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to two equivalent Mo6+ atoms. In the fourth O2- site, O2- is bonded in a single-bond geometry to one N5+ atom. In the fifth O2- site, O2- is bonded in a distorted L-shaped geometry to one Mo6+ and one N5+ atom. In the sixth O2- site, O2- is bonded in a distorted L-shaped geometry to one Mo6+ and one N5+ atom. In the seventh O2- site, O2- is bonded in a distorted L-shaped geometry to one Mo6+ and one N5+ atom. In the eighth O2- site, O2- is bonded in a distorted L-shaped geometry to one Mo6+ and one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Magnetostriction and damping of forced vibrations in Fe-Mo single and polycrystal alloys

Magnetostriction and damping of forced vibrations in Fe-Mo single and polycrystal alloys is studied and analyzed with respect to existing approaches and experimental data. In this work, our data suggest that a more complex dependence (compared with linear dependence predicted by Smith and Birchak) between damping capacity and magnetostriction takes place for this and possibly other Fe-based ferromagnetic alloys. We believe that more factors related to the structural changes, brought about by the additions (elements added to Fe), which can affect phase stability as well as magnetic and electric contributions influencing property response, should be considered to provide a better correlation between the magnetic and magnetomechanical characteristics of this alloy.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Atom probe tomography of segregation at grain boundaries and gas bubbles in neutron irradiated U-10 wt% Mo fuel

During neutron irradiation to fission densities > 5.2 × 10 21 fiss/cm 3 , Xe agglomerates forming gas bubbles of varying size within the U-Mo fuel matrix. Herein, segregation of fission products to Xe bubbles and grain boundaries (GB) were studied using atom probe tomography (APT). Segregation behavior was found to vary among GBs, small bubbles (<10 nm), and larger bubbles (>10 nm). Solid fission products were enriched at GBs and larger bubbles, but not at small bubbles. Finally, a denuded zone was identified adjacent to a > 10 nm Xe gas bubble and a GB.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Transformation and twinning induced plasticity in metastable Ti-Mo alloys under high strain rate deformation

The development of metastable titanium (Ti) alloys provides an unprecedented opportunity to expand their use in plasticity and damage critical applications like protective structures. However, such applications require knowledge of quasi-static to dynamic mechanical behavior, which is currently lacking. Here we perform in-situ, ultrafast synchrotron x-ray diffraction during high strain rate (Kolsky) pressure bar testing in tension and post-mortem electron microscopy to study TRansformation Induced Plasticity (TRIP) and TWinning Induced Plasticity (TWIP) in metastable Ti-Mo alloys. Two alloys, namely Ti-12Mo and Ti-15Mo (wt.%), were selected for study having different β -phase chemical stabilities. TWIP was observed in both Ti-12Mo and Ti-15Mo by in-situ synchrotron diffraction during high strain rate testing. Post-mortem microstructural characterization also revealed the presence of TRIP in Ti-12Mo. TWIP in Ti-15Mo was found to under-perform in terms of total elongation compared to TRIP/TWIP in Ti-12Mo. Ti-12Mo exhibited an average elongation of 17% compared to only 12% for Ti-15Mo with deformation at 1000 s -1 . In conclusion, TRIP resulted in significantly finer microstructure evolution and alleviated local strain accumulations in Ti-12Mo, suggesting TRIP can be used to tune available strength/ductility combinations in metastable Ti alloys under high strain rate deformation conditions.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Mechanical Properties of Irradiated U-10 wt. %Mo Alloy Degraded by Porosity Development

In this study, a plate-type nuclear fuel consisting of a solid monolithic foil of U-10 wt. %Mo is under development for use in the United States' high-performance research reactors. In support of developing this fuel, the fuel has been fabricated for the first time by a commercial fuel vendor and subsequently irradiated in a test reactor. This provides an opportunity to evaluate postirradiation mechanical properties of the commercially fabricated fuel. Four-point bend testing was conducted on the irradiated U-10Mo samples to generate the fuel material properties, including the modulus of elasticity and the bending strength. Although the material behaves in a brittle manner due to the accumulated porosity, a general trend of strength and modulus reduction was found as fission density increases. The data produced was evaluated using both Weibull statistics and a modulus degradation model with recommendations provided.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Evaluation of a Combined Raffinate Waste Stream for Mo-99 Production

Niowave, Inc., based in Lansing, Michigan, intends to produce Mo-99 from the fission of low enriched uranium (LEU) targets. In FY20, SRNL was tasked to provide technical assistance in identifying the primary waste raffinate present in Niowave’s commercial scale system and evaluating methods for disposal. Due to limited information on Niowave’s complete flowsheet and isotope recovery plans, a combined raffinate stream including the entire radionuclide inventory from the irradiated fuel was used for this evaluation. Results of the evaluation indicated the majority of the waste generated can be expected to be Class A; however radioisotopes such as Pu-239, Cs-137, Sr-90, and some of the shorter lived (< 5 year half-life) may challenge Niowave’s ability to meet the waste acceptance criteria for land burial. With appropriate waste management strategies, it is probable that Niowave’s waste could meet Class C requirements for all constituents, with the possible exception of Pu-239. More detailed information of Niowave’s processes are needed to form a more accurate understanding required to execute and effective, economic, and feasible waste management strategy.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗