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DOE OSTI2020

Materials Data on VCr(P2O7)2 by Materials Project

VCr(P2O7)2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. V5+ is bonded to six O2- atoms to form VO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of V–O bond distances ranging from 1.85–1.94 Å. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Cr–O bond distances ranging from 2.00–2.02 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one VO6 octahedra, corners with two equivalent CrO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 39–49°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one VO6 octahedra, corners with two equivalent CrO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–49°. There are a spread of P–O bond distances ranging from 1.51–1.64 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CrO6 octahedra, corners with two equivalent VO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–45°. There are a spread of P–O bond distances ranging from 1.49–1.60 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CrO6 octahedra, corners with two equivalent VO6 octahedra, and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 40–48°. There are a spread of P–O bond distances ranging from 1.50–1.60 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one V5+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one V5+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one V5+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one V5+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one V5+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr3+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr3+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one V5+ and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Cr3+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr3+ and one P5+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on VCr(CuO2)2 by Materials Project

VCr(CuO2)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. V3+ is bonded to six O2- atoms to form VO6 octahedra that share edges with two equivalent VO6 octahedra and edges with four equivalent CrO6 octahedra. There are four shorter (2.04 Å) and two longer (2.09 Å) V–O bond lengths. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share edges with two equivalent CrO6 octahedra and edges with four equivalent VO6 octahedra. There are four shorter (2.03 Å) and two longer (2.04 Å) Cr–O bond lengths. Cu1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.84 Å) and one longer (1.86 Å) Cu–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one V3+, two equivalent Cr3+, and one Cu1+ atom to form distorted OVCr2Cu trigonal pyramids that share corners with five equivalent OV2CrCu tetrahedra, corners with five equivalent OVCr2Cu trigonal pyramids, edges with two equivalent OV2CrCu tetrahedra, and an edgeedge with one OVCr2Cu trigonal pyramid. In the second O2- site, O2- is bonded to two equivalent V3+, one Cr3+, and one Cu1+ atom to form distorted OV2CrCu tetrahedra that share corners with five equivalent OV2CrCu tetrahedra, corners with five equivalent OVCr2Cu trigonal pyramids, an edgeedge with one OV2CrCu tetrahedra, and edges with two equivalent OVCr2Cu trigonal pyramids.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on VCr by Materials Project

CrV is Tungsten-derived structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. V is bonded in a distorted body-centered cubic geometry to four equivalent V and four equivalent Cr atoms. All V–V bond lengths are 2.53 Å. All V–Cr bond lengths are 2.51 Å. Cr is bonded in a distorted body-centered cubic geometry to four equivalent V and four equivalent Cr atoms. All Cr–Cr bond lengths are 2.53 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on VCr(PO4)2 by Materials Project

Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

36 MATERIALS SCIENCE↗

DOE OSTI2022

Container Evaluation: Analysis of the Swagelok Knuckle with Viewport as an Approved Hermetically Sealed Inner Container

This report outlines the results from the water ingress test, helium leak test and additional atmosphere testing for the Swagelok knuckle with viewport container further referred to as the SKV. This container is constructed from a standard union vacuum fitting, 1.33” conflat to 0.5” male VCR, a 1.33” conflat fused silica lensed viewport fitting, and a 0.5 inch VCR cap. The primary intended use of this container is to store Pu metal samples in the vault for a time interval exceeding 40 years. The samples need to be contained in an air free environment to ensure that the material does not oxidize over time. The container viewport is a critical design feature that will help the operators visually inspect and evaluate the state of the metal samples prior to opening the container. These containers are advertised as leak tight, but experimental tests were performed to test the water resistant criteria and the gas leaking criteria set forth by the TA-55 Criticality Safety Program. The results of the water ingress test show that the container is water-tight, with no signs of water penetrating the container within the required guidelines outlined in TA55-AP-522. The preliminary He leak test performed demonstrate that the conflat window port and VCR cap are able to maintain a hermetic seal. Additionally, all containers will be He leak tested independently by the manufacturer prior to shipping to LANL. A third voluntary test was added to assess the container’s ability to hold atmosphere, with successful results indicating the container is able to hold inert atmosphere to prevent lanthanum metal oxidation. It is the conclusion of the authorsthat there is enough evidence through the test conducted and outlined within this document that the proposed container meets the definition of a water-tight container, and it is able to provide a hermetic seal.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2023

Progress Report of Alloy 709 Performance in Liquid Sodium

With improved high-temperature properties, Alloy 709 shows great potential for advanced reactor applications. To understand the effects of sodium on A709, small tensile specimens were machined from two commercial heats and subject to sodium exposure in two forced convection loops operated by Argonne. Thermal aging experiments were also conducted in parallel to isolate any sodium-specific effects. An increasing trend in yield strength and a decrease trend in ultimate tensile strength can be seen with the increasing exposure time, suggesting microstructural changes at these temperatures. Nonetheless, the thermally aged and sodium exposed samples behaved similarly, implying no sodium-specific effect at these temperatures. In contrast, 316H SS exposed to sodium at 650°C showed a strong sodium effect. The different responses of A709 and 316H SS to sodium exposure is of interest and requires additional effort to understand. The cold traps of the sodium loop were replaced early in FY23. During a maintenance operation, an unexpected sodium leak incident occurred at one of the sodium loops, triggering an emergency response. An investigation into the incident revealed that the leak happened at a VCR fitting on the recently replaced cold trap. The metal gasket of the leaked VCR fitting was not compressed sufficiently. A dimensional mismatch between the new component and old piping configuration was responsible for a significant misalignment. A new cold trap with improved design is in production. The new design provides additional flexibility and an access point for post-installation helium leak check and for venting of trapped gas. These design features will make the system more error-tolerant and the installation quality verifiable. A thermodynamic analysis was performed to understand the carburization-decarburization behavior of A709 in sodium environment. The equilibrium carbon activity in the alloy was evaluated with M 23 C 6 , TiC, and NbC. The carburization-decarburization boundary was calculated with different methods developed previously. The results suggests that A709 will be carburized in SMT-1 and SMT-2, and can be decarburized in low-carbon-activity environments such as EBR-II at temperatures above 620-650°C. Nonetheless, A709 should be less likely to be decarburized than 316H SS when exposed to the same low-carbon-activity environment.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2020

Counter-Intuitive Structural Instability Aroused by Transition Metal Migration in Polyanionic Sodium Ion Host

The structure of polyanionic materials is conventionally known to be free of transition metal migration and structurally stable when storing/releasing sodium ions. Herein, the observation of enhanced cycling stability of a typical polyanionic cathode, Na 3 VCr(PO 4 ) 3 (NVCP) at lower temperature (-15 degrees C vs 30 degrees C), triggers the exploration of its structural origins with a surprising finding that the migratable nature of vanadium in NVCP leads to detrimental structural degradation of the polyanionic host upon cycling. The correlation between long range and short range structural change associated with this atomic migration is established via a strong combination of various in situ/ex situ characterization tools, revealing the essential V-to-Na1 site migration. Such transition metal migration is effectively suppressed when V atoms are pinned to their original position in the lattice by lowering the temperature. More importantly and practically, a room temperature-based deep sodiation strategy is further developed to recover the structure. Overall, this work challenges the long-standing assumption of the stability of the polyanionic framework structure and calls for urgent attention to the structural understanding of the NVCP system as well as strategy development for property enhancement.

25 ENERGY STORAGE↗

DOE OSTI2020

Materials Data on VCrB2 by Materials Project

(VCr)B2 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. V3+ is bonded in a 7-coordinate geometry to seven B3- atoms. There are a spread of V–B bond distances ranging from 2.20–2.30 Å. Cr3+ is bonded in a 7-coordinate geometry to seven B3- atoms. There are a spread of Cr–B bond distances ranging from 2.20–2.31 Å. There are two inequivalent B3- sites. In the first B3- site, B3- is bonded in a 9-coordinate geometry to four equivalent V3+, three equivalent Cr3+, and two equivalent B3- atoms. Both B–B bond lengths are 1.78 Å. In the second B3- site, B3- is bonded in a 9-coordinate geometry to three equivalent V3+, four equivalent Cr3+, and two equivalent B3- atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2023

CORPSE model with litter decomposition parameters derived from the LIDET dataset

This is a version of the CORPSE model (Carbon, Organisms, Rhizosphere and Protection in the Soil Environment, Sulman et al. 2014) that uses litter decomposition parameters derived from a modified Monte Carlo simulation using the LIDET litter decomposition dataset (Long-term Intersite Decomposition Experiment Team, Harmon 2013). The code also includes the Baseline parameters, and the eight other best parameter sets identified in a modified Monte Carlo simulation. Related publication:Juice, S.M., Ridgeway, J.R., Hartman, M.D., Parton, W.J., Berardi, D.M., Sulman, B.N., Allen, K.E., & Brzostek, E.R. Reparameterizing litter decomposition using a simplified Monte Carlo method improves litter decay simulated by a microbial model and alters bioenergy soil carbon estimates. Description of files:The folder "Input Files" contains one folder for each LIDET site with data necessary to run the model. Note that "(site)" in the filenames below indicates where the LIDET site code appears (see Table 1 for site codes). Data streams include: CORPSE_full_spinup_litter.csv, CORPSE_full_spinup_rhizo.csv, CORPSE_full_spinup_bulk.csv, litterbag_init_100g_6spp.csv: initial C and N (kg C or N/m2) pool values for each soil layer, the litterbag_init_100_6spp.csv file is for the litterbag layer and is the same file for all sites. All initial C and N files have the same columns (Column - Description - Units) uFastC - Unprotected fast decomposing carbon - kg carbon/m2 uSlowC - Unprotected slow decomposing carbon - kg carbon/m2 uNecroC - Unprotected necromass carbon - kg carbon/m2 pFastC - Protected fast decomposing carbon - kg carbon/m2 pSlowC - Protected slow decomposing carbon - kg carbon/m2 pNecroC - Protected necromass carbon - kg carbon/m2 livingMicrobeC - Carbon in living microbial biomass - kg carbon/m2 uFastN - Unprotected fast decomposing nitrogen - kg nitrogen/m2 uSlowN - Unprotected slow decomposing nitrogen - kg nitrogen/m2 uNecroN - Unprotected necromass nitrogen - kg nitrogen/m2 pFastN - Protected fast decomposing nitrogen - kg nitrogen/m2 pSlowN - Protected slow decomposing nitrogen - kg nitrogen/m2 pNecroN - Protected necromass nitrogen - kg nitrogen/m2 inorganicN - Inorganic nitrogen - kg nitrogen/m2 CO2 - Carbon in carbon dioxide - kg carbon/m2 livingMicrobeN - Nitrogen in living microbial biomass - kg nitrogen/m2 soilT (site) DOY274start.csv: Average daily soil temperature (oC) interpolated from previously calculated monthly values used in DayCent LIDET simulations (Bonan et al., 2013). soilT (site) DOY274start.csv: Average daily soil volumetric water content (VWC) scalar interpolated from previously calculated monthly values used in DayCent LIDET simulations (Bonan et al., 2013). litter production.csv: Average daily litter production values for each site, data sources listed in Table S3 of related publication. litter (site) CN.csv: C:N ratio for each species from LIDET dataset (Table 2, Harmon 2013). (site).csv: Table indicating number of observations for each species decomposed at each site. Instructions: Save the model code ("CORPSE_LIDET.R") and "Input Files" folder in the same folder. Also make a folder for the model output (e.g., "results_Baseline") in the same folder. Set the working directory (setwd) in the model code to the folder with the files saved in step #1. Select the parameter set to use for the litter and litterbag compartments, comment out all other parameter sets. Run code. Output will be saved in the folder made in step 1. Output destination can be changed as necessary in code section called "Running the model." Table 1 LIDET sites and site codes used in model files. Site Code - Site AND - H.J. Andrews Experimental Forest BNZ - Bonanza Creek Experimental Forest BSF - Blodgett Research Forest CDR - Cedar Creek Natural History Area CPR - Central Plains Experimental Range HBR - Hubbard Brook Experimental Forest HFR - Harvard Forest JUN - Juneau KBS - Kellogg Biological Station KNZ - Konza Prairie Research Natural Area NWT - Niwot Ridge/Green Lakes Valley OLY - Olympic National Park OLY Conifer forest SEV - Sevilleta National Wildlife Refuge SMR - Santa Margarita Ecological Reserve UFL - University of Florida VCR - Virginia Coast Reserve Table 2 LIDET species and species codes used in model files (6 common species). Species - Species Code Sugar maple (Acer saccharum) - ACSA Drypetes (Drypetes glauca) - DRGL Red pine (Pinus resinosa) - PIRE Chestnut oak (Quercus prinus) - QUPR Western redcedar (Thuja plicata) - THPL Wheat (Triticum aestivum) - TRAE References:Bonan, G. B., Hartman, M. D., Parton, W. J., & Wieder, W. R. (2013). Evaluating litter decomposition in earth system models with long-term litterbag experiments: an example using the Community Land Model version 4 (CLM4). Global Change Biology, 19(3), 957-974. https://doi.org/https://doi.org/10.1111/gcb.12031 Harmon, M. (2013). LTER Intersite Fine Litter Decomposition Experiment (LIDET), 1990 to 2002. Long-Term Ecological Research. Forest Science Data Bank, Corvallis, OR. [Data set]. Accessed http://andlter.forestry.oregonstate.edu/data/abstract.aspx?dbcode=TD023. https://doi.org/10.6073/pasta/f35f56bea52d78b6a1ecf1952b4889c5. Sulman, B. N., Phillips, R. P., Oishi, A. C., Shevliakova, E., & Pacala, S. W. (2014). Microbe-driven turnover offsets mineral-mediated storage of soil carbon under elevated CO2. Nature Climate Change, 4, 1099 - 1102. https://doi.org/10.1038/nclimate2436

Juice, Stephanie↗