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Deuteron-induced reactions on natural Zr from threshold to 50 MeV: production of 86g Y

Two stacks of thin Zr foils were irradiated with 30 and 50 MeV deuterons, respectively, using the Lawrence Berkeley National Laboratory 88-Inch Cyclotron, and 19 excitation functions for nat Zr(d,x) reactions were measured over a beam energy range of 6.3–47.64 MeV, where the independent cross sections for nat Zr(d,x) 88 Nb and nat Zr(d,x) 86m,g Y were measured for the first time. The well-characterized nat Fe(d,x) 56 Co, nat Ni(d,x) 56 Co, nat Ni(d,x) 58 Co, nat Ni(d,x) 61 Cu, nat Ti(d,x) 46 Sc and nat Ti(d,x) 48 V monitor reactions were used to determine the deuteron beam current throughout the stacks. All cross sections were determined using High Purity Germanium (HPGe) detector γ-ray spectroscopy. A variance minimization technique was employed to simultaneously constrain the deuteron beam currents with multiple monitor reactions, thus reducing systematic uncertainties. An additional 16 channels are reported for reactions on the nickel, titanium, and iron monitor foils, leading to a total of 35 excitation functions, with seven reaction channels reported for the first time in this work. The measured excitation functions are compared to calculations provided by the reaction modeling codes TALYS – 2.0, ALICE – 2020, CoH – 3.5.3 and EMPIRE – 3.2.3, as well as the TENDL – 2023 data library. The degree of agreement between theory and experiments is discussed. The possible production of the important PET radionuclide 86g Y via the nat Zr(d,x) route was critically examined. The physical yields for nat Zr(d,x) 86 Y and other yttrium isotopes produced were calculated and compared to other production pathways. Due to high-level of associated radionuclide impurities, this route cannot deliver 86g Y suitable for medical applications.

86gY↗

Materials Data on Zr(Fe2Si)2 by Materials Project

ZrFe4Si2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Zr is bonded in a 6-coordinate geometry to twelve equivalent Fe and six equivalent Si atoms. There are four shorter (3.03 Å) and eight longer (3.13 Å) Zr–Fe bond lengths. There are two shorter (2.77 Å) and four longer (2.83 Å) Zr–Si bond lengths. Fe is bonded in a 12-coordinate geometry to three equivalent Zr, six equivalent Fe, and three equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.38–2.58 Å. There are one shorter (2.31 Å) and two longer (2.35 Å) Fe–Si bond lengths. Si is bonded in a 9-coordinate geometry to three equivalent Zr and six equivalent Fe atoms.

36 MATERIALS SCIENCE↗

Materials Data on Zr(PO3)4 by Materials Project

Zr(PO3)4 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are four inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.12–2.37 Å. In the second Zr4+ site, Zr4+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.11–2.37 Å. In the third Zr4+ site, Zr4+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.14–2.41 Å. In the fourth Zr4+ site, Zr4+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.14–2.37 Å. There are sixteen inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the fifth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the sixth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the seventh P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the eighth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the ninth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the tenth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the eleventh P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the twelfth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the thirteenth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the fourteenth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.60 Å. In the fifteenth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.61 Å. In the sixteenth P5+ site, P5+ is bonded to four O2- atoms to form corner-sharing PO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.49–1.60 Å. There are forty-eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a distorted linear geometry to one Zr4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the fourteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Zr4+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Zr4+ and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the seventeenth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Zr4+ and one P5+ atom. In the nineteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the twentieth O2- site, O2- is bonded in a 2-coordinate geometry to one Zr4+ and one P5+ atom. In the twenty-first O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the twenty-second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the twenty-third O2- site, O2- is bonded in a distorted single-bond geometry to one Zr4+ and one P5+ atom. In the twenty-fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Zr4+ and one P5+ atom. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the twenty-sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the twenty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the twenty-eighth O2- site, O2- is bonded in a distorted single-bond geometry to one Zr4+ and one P5+ atom. In the twenty-ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the thirtieth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the thirty-first O2- site, O2- is bonded in a bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the thirty-second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the thirty-third O2- site, O2- is bonded in a bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the thirty-fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the thirty-fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Zr4+ and one P5+ atom. In the thirty-sixth O2- site, O2- is bonded in a 1-coordinate geometry to one Zr4+ and one P5+ atom. In the thirty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the thirty-eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the thirty-ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Zr4+ and one P5+ atom. In the fortieth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the forty-first O2- site, O2- is bonded in a bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the forty-second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the forty-third O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the forty-fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the forty-fifth O2- site, O2- is bonded in a distorted linear geometry to one Zr4+ and one P5+ atom. In the forty-sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the forty-seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Zr4+ and one P5+ atom. In the forty-eighth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms.

36 MATERIALS SCIENCE↗

Materials Data on Zr(Zn10Co)2 by Materials Project

Zr(CoZn10)2 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Zr is bonded in a 4-coordinate geometry to sixteen Zn atoms. There are four shorter (3.01 Å) and twelve longer (3.06 Å) Zr–Zn bond lengths. Co is bonded to twelve Zn atoms to form CoZn12 cuboctahedra that share corners with six equivalent CoZn12 cuboctahedra, edges with eighteen equivalent ZnZrZn10Co cuboctahedra, and faces with six equivalent ZnZrZn10Co cuboctahedra. There are six shorter (2.47 Å) and six longer (2.72 Å) Co–Zn bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded in a distorted linear geometry to two equivalent Co and ten Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.62–2.75 Å. In the second Zn site, Zn is bonded to one Zr, one Co, and ten Zn atoms to form distorted ZnZrZn10Co cuboctahedra that share corners with fifteen equivalent ZnZrZn10Co cuboctahedra, edges with two equivalent ZnZrZn10Co cuboctahedra, edges with three equivalent CoZn12 cuboctahedra, a faceface with one CoZn12 cuboctahedra, and faces with fifteen equivalent ZnZrZn10Co cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.57–2.96 Å. In the third Zn site, Zn is bonded in a 2-coordinate geometry to two equivalent Zr and twelve equivalent Zn atoms.

36 MATERIALS SCIENCE↗

Materials Data on Zr(Zn10Fe)2 by Materials Project

Zr(FeZn10)2 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Zr is bonded in a 4-coordinate geometry to sixteen Zn atoms. There are four shorter (3.03 Å) and twelve longer (3.07 Å) Zr–Zn bond lengths. Fe is bonded to twelve Zn atoms to form FeZn12 cuboctahedra that share corners with six equivalent FeZn12 cuboctahedra, edges with eighteen equivalent ZnZrZn10Fe cuboctahedra, and faces with six equivalent ZnZrZn10Fe cuboctahedra. There are six shorter (2.48 Å) and six longer (2.73 Å) Fe–Zn bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded in a 2-coordinate geometry to two equivalent Fe and ten Zn atoms. There are a spread of Zn–Zn bond distances ranging from 2.64–2.76 Å. In the second Zn site, Zn is bonded to one Zr, one Fe, and ten Zn atoms to form ZnZrZn10Fe cuboctahedra that share corners with fifteen equivalent ZnZrZn10Fe cuboctahedra, edges with two equivalent ZnZrZn10Fe cuboctahedra, edges with three equivalent FeZn12 cuboctahedra, a faceface with one FeZn12 cuboctahedra, and faces with fifteen equivalent ZnZrZn10Fe cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.59–2.98 Å. In the third Zn site, Zn is bonded in a 2-coordinate geometry to two equivalent Zr and twelve equivalent Zn atoms.

36 MATERIALS SCIENCE↗

Materials Data on Zr(Zn10Ni)2 by Materials Project

Zr(NiZn10)2 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Zr is bonded in a 4-coordinate geometry to sixteen Zn atoms. There are four shorter (3.02 Å) and twelve longer (3.05 Å) Zr–Zn bond lengths. Ni is bonded to twelve Zn atoms to form NiZn12 cuboctahedra that share corners with six equivalent NiZn12 cuboctahedra, edges with eighteen equivalent ZnZrZn10Ni cuboctahedra, and faces with six equivalent ZnZrZn10Ni cuboctahedra. There are six shorter (2.47 Å) and six longer (2.74 Å) Ni–Zn bond lengths. There are three inequivalent Zn sites. In the first Zn site, Zn is bonded in a distorted linear geometry to two equivalent Ni and six equivalent Zn atoms. There are two shorter (2.63 Å) and four longer (2.76 Å) Zn–Zn bond lengths. In the second Zn site, Zn is bonded to one Zr, one Ni, and ten Zn atoms to form distorted ZnZrZn10Ni cuboctahedra that share corners with fifteen equivalent ZnZrZn10Ni cuboctahedra, edges with two equivalent ZnZrZn10Ni cuboctahedra, edges with three equivalent NiZn12 cuboctahedra, a faceface with one NiZn12 cuboctahedra, and faces with fifteen equivalent ZnZrZn10Ni cuboctahedra. There are a spread of Zn–Zn bond distances ranging from 2.57–2.96 Å. In the third Zn site, Zn is bonded in a 2-coordinate geometry to two equivalent Zr and twelve equivalent Zn atoms.

36 MATERIALS SCIENCE↗

TEM characterization of two variants of fuel cladding chemical interaction in a HT-9 Clad U-10Zr Fuel. Variant 1: FCCI with a Zr Rind

Here, this study investigated the fuel cladding chemical interaction (FCCI), a key factor that limits operational temperature and burnup, in an HT-9 clad U-10Zr nuclear fuel sample irradiated to a high burnup of 13.1 at.% at a time-averaged peak inner cladding temperature (PICT) of 530 °C. Previous results showed this fuel sample exhibited two distinct levels of FCCI at d. This paper analyzed the FCCI at an azimuthal position showing an interdiffusion layer of <10 µm using transmission electron microscopy to examine chemical and crystallographic nature of phases at the fuel-cladding interface at the nanoscale level. A ZrC layer and a Zr 3 Si phase were identified at the interface; these, along with the relatively low local temperature, potentially contributed to limit interdiffusion, behaving as inhibitors for deleterious interactions. Lanthanides (Ln) partially consumed the ZrC layer and interacted with Fe, forming a Zr-Ln compound and a (Zr,Ce)Fe 2+x phase while also infiltrating up to 4 µm into the cladding. Neither U nor Zr were observed in the cladding, whereas Fe diffused up to 3–5 µm in the fuel. Fe infiltration formed a ternary U-Zr-Fe ε-phase and likely promoted the precipitation of a Cr-rich α’ phase on the cladding interface. Additionally, a Cr-rich χ-phase, likely formed by the dissociation of pre-existing M 23 C 6 carbide precipitates, was identified about 2–5 µm from the fuel-cladding interface. Irradiation-induced nano-voids were also observed in the HT-9 bulk. These findings provide critical insights into FCCI mechanisms at representative irradiation conditions, essential for developing models simulating in-pile metallic fuel behaviors for next-generation reactors.

36 - MATERIALS SCIENCE↗

Thermo-mechanical behavior of hypoeutectic Ni-Y-Zr alloys

Microstructure refinement and optimized alloying can improve metallic alloy performance: stable nanocrystalline (NC) alloys with immiscible second phases, e.g., Cu-Ta, are stronger than unstable NC alloys and their coarse-grained (CG) counterparts, but higher melting point matrices are needed. Hypoeutectic, CG Ni-Y-Zr alloys were produced via arc-melting to explore their potential as high-performance materials. Microstructures were studied to determine phases present, local composition and length scales, while heat treatments allowed investigating microstructural stability. Alloys had a stable, hierarchical microstructure with ~250 nm ultrafine eutectic, ~10 µm dendritic arm spacing and ~1 mm grain size. Hardness and uniaxial compression tests revealed that mechanical properties of Ni-0.5Y-1.8Zr (in wt%) were comparable to Inconel 617 despite the small alloying additions, due to its hierarchical microstructure. Here, uniaxial compression at 600 °C showed that ternary alloys outperformed Ni-Zr and Ni-Y binary alloys in flow stress and hardening rates, which indicates that the Ni 17 Y 2 phase was an effective reinforcement for the eutectic, which supplemented the matrix hardening due to increased solubility of Zr. Results suggest that ternary Ni-Y-Zr alloys hold significant promise for high temperature applications.

36 MATERIALS SCIENCE↗

Materials Data on Zr by Materials Project

Zr is Magnesium structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Zr is bonded to twelve equivalent Zr atoms to form a mixture of corner, edge, and face-sharing ZrZr12 cuboctahedra. There are six shorter (3.19 Å) and six longer (3.24 Å) Zr–Zr bond lengths.

36 MATERIALS SCIENCE↗

Materials Data on Zr by Materials Project

Zr is Tungsten structured and crystallizes in the cubic Im-3m space group. The structure is three-dimensional. Zr is bonded in a distorted body-centered cubic geometry to eight equivalent Zr atoms. All Zr–Zr bond lengths are 3.10 Å.

36 MATERIALS SCIENCE↗

Materials Data on Zr by Materials Project

Zr is Copper structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Zr is bonded to twelve equivalent Zr atoms to form a mixture of face, edge, and corner-sharing ZrZr12 cuboctahedra. All Zr–Zr bond lengths are 3.21 Å.

36 MATERIALS SCIENCE↗

Materials Data on Zr by Materials Project

Zr is Hg_xSn structured and crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Zr is bonded to eight equivalent Zr atoms to form a mixture of corner and edge-sharing ZrZr8 hexagonal bipyramids. There are six shorter (3.01 Å) and two longer (3.04 Å) Zr–Zr bond lengths.

36 MATERIALS SCIENCE↗

Experimental and Modeling Review of the Plutonium-Zirconium (Pu-Zr) System: Lost in Translation and Over Time?

This article presents a review of the phase equilibria of the Pu-Zr system and discusses the contradictory reports on the experimental phase diagram and misinterpretations that have led to confusion over time. In addition, a review of the few Pu-Zr CALPHAD (CALculation of PHAse Diagrams) assessments is presented with emphasis on the heat of formation of the bcc phase, highlighting a disagreement between CALPHAD and ab initio calculations. Based on the information gathered in this study, a critical re-assessment of the Pu-Zr system involving the ζ (Pu 28 Zr), θ (Pu 4 Zr), kinetically hindered κ (PuZr 2 ), and once observed ι phases is called for.

36 MATERIALS SCIENCE↗

Enhanced low temperature performance of bimetallic Pd/Pt/SiO 2 (core)@Zr(shell) diesel oxidation catalysts

Here, in this study, the diesel oxidation performance of degreened (DG) and hydrothermally aged monometallic and bimetallic Pd/Pt/SiO 2 (core)@Zr(shell) catalysts with varying Pd/Pt molar ratios from 3/1–1/3 was evaluated. Pd/Pt(3/1)/SiO 2 @Zr (DG) achieved 50% and 90% conversion of CO at 166 °C (T 50 ), 169 °C (T 90 ) and total hydrocarbons (THCs) at 198 °C (T 50 ), 244 °C (T 90 ). Decreasing the Pd/Pt molar ratio led to a decrease in the T 50,90 ’s, with Pd/Pt(1/3)/SiO 2 @Zr (DG) achieving T 50,90 ’s at 153, 156 °C for CO and 171, 200 °C for THCs, respectively. Moreover, Pd/Pt(1/3)/SiO 2 @Zr showed enhanced hydrothermal stability. XRD and TEM showed that in the hydrothermally aged bimetallic catalysts, the fraction of Pd present as a Pt-Pd metallic alloy increased with Pt content. The enhanced low temperature performance of Pd/Pt(1/3)/SiO 2 @Zr compared to the other studied catalysts was attributed to Pd being primarily present in metallic form, despite being subjected to severe oxidizing conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Solid-phase isotope harvesting of 88 Zr from a radioactive ion beam facility

During routine operation of the Facility for Rare Isotope Beams (FRIB), radionuclides will accumulate in both the aqueous beam dump and along the beamline in the process of beam purification. These byproduct radionuclides, many of which are far from stability, can be collected and purified for use in other scientific applications in a process called isotope harvesting. In this work, the viability of 88 Zr harvesting from solid components was investigated at the National Superconducting Cyclotron Laboratory. A secondary 88 Zr beam was stopped in a series of collectors comprised of Al, Cu, W, and Au foils. Here, this work details irradiation of the collector foils and the subsequent radiochemical processing to isolate the deposited 88 Zr (and its daughter 88 Y) from them. Total average recovery from the Al, Cu, and Au collector foils was (91.3 ± 8.9) % for 88 Zr and (95.0 ± 5.8) % for 88 Y, respectively, which is over three times higher recovery than in a previous aqueous-phase harvesting experiment. The utility of solid-phase isotope harvesting to access elements such as Zr that readily hydrolyze in near-neutral pH aqueous conditions has been demonstrated for application to harvesting from solid components at FRIB.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Harvesting 88 Zr from heavy-ion beam irradiated tungsten at the National Superconducting Cyclotron Laboratory

Tungsten is a commonly used material at many heavy-ion beam facilities, and it often becomes activated due to interactions with a beam. Many of the activation products are useful in basic and applied sciences if they can be recovered efficiently. In order to develop the radiochemistry for harvesting group (IV) elements from irradiated tungsten, a heavy-ion beam containing 88 Zr was embedded into a stack of tungsten foils at the National Superconducting Cyclotron Laboratory and a separation methodology was devised to recover the 88 Zr. The foils were dissolved in 30% hydrogen peroxide, and the 88 Zr was chemically purified from the tungsten matrix and from other co-implanted radionuclides (such as 85 Sr and 88 Y) using strong cation-exchange (AG MP-50) chromatographic resin in sulfuric acid media. The procedure provided 88 Zr in approximately 60 mL 0.5 M sulfuric acid with no detectable radio-impurities. The overall recovery yield for 88 Zr was (92.3 ± 1.2)%. In conclusion, this proof-of-concept experiment has facilitated the development of methodologies to harvest from tungsten and tungsten-alloy parts that are regularly irradiated at heavy-ion beam facilities.

07 ISOTOPE AND RADIATION SOURCES↗

Relative phase stability of L1 2 and DO 22 /DO 23 structures in Al 3 Nb, Al 3 Zr and Al 3 V compounds

The relative stability of the different tri-aluminide (Al 3 M) phases in three binary systems (M = Zr, Nb and V) was assessed for their potential to form fine cubic L1 2 precipitates in additively manufactured alloys. Supersaturated thin films of Al-(8–30) at% M were sputtered and heat treated during in-situ x-ray diffraction (XRD) measurements to observe the temperature ranges of stability for each phase. As-sputtered films were then processed with laser tracks simulating additive manufacturing solidification conditions, and the formation of phases in the laser tracks was correlated with density functional theory (DFT) and nucleation rate calculations. We found that the metastable L1 2 structure is highly competitive with the stable DO 23 structure in the Al-Zr system, but much less stable than the DO 22 structure in the Al-Nb system, and both the DO 22 and Al 8 V 5 structure in the Al-V system. Furthermore, these experimental results were found to be in good agreement with the DFT and kinetic calculations, as we determined that the metastable L1 2 in Al-Zr only requires a small amount of undercooling to favor its nucleation over the stable DO 23 , suggesting additive manufacturing can be a viable pathway to develop Al-Zr alloys strengthened by a high volume fraction of L1 2 Al 3 Zr phase.

Perrin, Alice E. [Oak Ridge National Laboratory (O↗

Phase evolution of U-Zr system in a thermal cycling neutron diffraction experiment: as-cast U-35Zr and U-50Zr

Here, phase evolution of as-cast U-35 wt% Zr and U-50 wt% Zr alloys during thermal cycling (303–1073 K) was investigated using in-situ neutron diffraction. Analysis was performed using Rietveld crystal and microstructure refinements from time-of-flight neutron diffraction data, with a focus on evolution of lattice parameter, atom ordering, unit cell volume, and weight fractions during the thermal cycling. Disordered δ-UZr 2 and residual γ-(U,Zr) phase are retained in the field of δ of the U-Zr equilibrium phase diagram for the U-50Zr sample, and in the field between δ and α-U for the U-35Zr sample. The α phase that is present in the reported phase diagrams of U-Zr was not observed in the diffraction patterns. The evolutions of lattice parameter and unit cell volume of δ and γ are affected by both thermal expansion and chemistry.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗