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All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Impact of Thermal Scattering Law on Similarity Assessment in Light-Water or Polyethylene-Moderated Systems

A collaborative effort between Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory (ORNL) is underway to provide a technical basis and methodology for the criticality safety community to use the sum of fractions (SoF) method for generating limits for mixtures of “selected actinide nuclides” included in the ANSI/ANS 8.15 standard. The PNNL scope in this project is to define a range of mixtures of 233 U, 235 U, and 239 Pu moderated with either light water or polyethylene and to examine the critical masses for these mixtures. The ORNL scope is primarily to provide validation support for these studies. More complete discussion of the project and its validation aspects will be presented at the upcoming International Conference on Nuclear Criticality Safety (ICNC) this Fall in Sendai, Japan. Clear differences in benchmark similarity to application systems as assessed by the integral parameter ck are noted in the validation studies performed as part of this project as a function of moderator. The c k value is a correlation coefficient that represents that amount of shared uncertainty in k eff due to cross sections between two systems. Individual nuclide-reaction contributions between the two systems can be simply summed to arrive at the total c k value. Specifically, the c k values for light-water–moderated solution experiments are higher for a water-moderated application than for a polyethylene-moderated application. This result is neither totally unexpected nor surprising, but the magnitude of the difference was difficult to anticipate. The TSUNAMI sequence, in the SCALE 6.2.4 code package developed by ORNL, was used to generate eigenvalues and reactivity effects with perturbation-theory based approach through sensitivity coefficients for all nuclides in the system with all reactions and energy groups. The TSUNAMI-Indices and Parameters (IP) sequence then uses the sensitivity data generated through TSUNAMI to generate relational parameters (i.e., c k ) to determine the degree of similarity between systems. One detail of the SCALE material and data implementation must be discussed at this point. Several thermal scattering laws (TSLs) are available for 1 H. SCALE uses a different nuclide ID number for each TSL; essentially, each version of 1 H is treated as a unique nuclide. For example, 1 H bound in water ( 1 H-H2O) is assigned the nuclide ID 1001, whereas 1 H bound in polyethylene (h-poly) is assigned the nuclide ID 9001001. The same cross section data are used for all reactions in 1 H, regardless of TSL, except for scattering below the TSL cutoff energy. TSUNAMI-IP treats different nuclide IDs as different nuclides; thus, no uncertainty is shared between 1 H-H2O and h-poly, despite much of the same data, including covariance data, being used for both nuclides. This presents a question: how much of the difference in assessed similarity between water- and polyethylene-moderated systems is due to the moderators, and how much is caused by the treatment of 1 H-H2O and h poly with cross section and covariance data. The extended edits generated by TSUANMI-IP allow for an investigation of this issue specifically, as well as a demonstration of the general techniques available within TSUNAMI to understand the results of the similarity assessment. This paper presents and analyzes the similarity assessment of both water- and polyethylene-moderated systems for a single benchmark: PST-002-001.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Effect of Plutonium on Uranium Oxide Microstructural Fingerprint

The analysis of particulates from environmental sampling is routinely performed for nuclear forensics applications. In order to increase the tools available for nuclear forensics applications, capability development materials (CDMs), or reference particulates, are necessary for developing and benchmarking new analytical methods. Historically, these CDM particulates have been produced with highly controlled and characterized isotopic and size parameters for applications in developing and benchmarking particle sizers and mass spectrometry analytical methods [1- 4]. However, the development of CDMs with highly characterized particle morphology and phase of the particles is vital for aiding in the development and benchmarking of particle analytical methods for those parameters. In many cases, key properties such as crystallographic phase, morphology, and microstructure, may be correlated to processing history of environmental sampling particulates [5]. To that end, this work investigates determining the structural fingerprint of produced Pu-doped uranium oxide CDMs using transmission electron microscopy (TEM). The particulates, one of which shown in Figure 1, were synthesized to Fig. 1. Single particulate of uranium oxide fabricated using the THESEUS technique. develop capabilities for environmental sampling investigations. These particles are monodisperse at diameter of 1 μm and a range of plutonium concentrations from 0- 1,000 ppm. Given their small diameter, TEM analysis was ideal for studying the particulate structural fingerprint in detail. Previous investigations confirmed the external homogeneity of the particulates at different plutonium concentrations, however this analysis focuses on determining the grain structure, phase distribution, and porosity of the particulates.

Mayer, Jack [Univ. of Florida, Gainesville, FL (Un↗
DOE OSTI2022

Raman Spectroscopy Characterization of Nuclear Materials and Soot from High Explosives

Vibrational and luminescence spectroscopy were used in the investigation of U and Pu-bearing compounds and soot from high explosives testing. Key spectroscopic signatures of UF4 and its hydrates, PuO 2 , and soot from different explosives will be presented. The United States Government retains and the publisher, by accepting this article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for United States Government purposes.

Villa-Aleman, Eliel↗
DOE OSTI2021

Plutonium in Manhattan Project workers: Using autopsy data to evaluate organ content and dose estimates based on urine bioassay with implications for radiation epidemiology

Purpose Radiation dose estimates in epidemiology typically rely on intake predictions based on urine bioassay measurements. The purpose of this article is to compare the conventional dosimetric estimates for radiation epidemiology with the estimates based on additional post-mortem tissue radiochemical analysis results. Methods The comparison was performed on a unique group of 11 former Manhattan Project nuclear workers, who worked with plutonium in the 1940s, and voluntarily donated their bodies to the United States Transuranium and Uranium Registries. Results Post-mortem organ activities were predicted using different sets of urine data and compared to measured activities. Use of urinalysis data collected during the exposure periods overestimated the systemic (liver+skeleton) deposition of 239 Pu by 155±134%, while the average bias from using post-exposure urinalyses was –4±50%. Committed effective doses estimated using early urine data differed from the best estimate by, on average, 196±193%; inclusion of follow-up urine measurements in analyses decreased the mean bias to 0.6±36.3%. Cumulative absorbed doses for the liver, red marrow, bone surface, and brain were calculated for the actual commitment period. Conclusion On average, post-exposure urine bioassay results were in good agreement with post-mortem tissue analyses and were more reliable than results of urine bioassays collected during the exposure.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Biogeochemistry of Pond B (Savannah River Site, South Carolina, USA): Water column and Sediments

Pond B at Savannah River Site (SRS, South Carolina) is a monomictic reservoir that received SRS R reactor cooling water from 1961–1964. Previous studies conducted between the 1980s–1990s on the water column and sediments of Pond B measured trace amounts of Pu (33 MBq 238Pu and 430 MBq 239,240Pu), 241Am, and 137Cs. Since then, the pond has been relatively isolated and the radionuclide concentrations have not been monitored over time. Herein, about 30 years after the last publication on Pond B, we are re-evaluating the geochemistry and radionuclide distribution within Pond B at five locations along a horizontal transect from the inlet to outlet. In addition, we are conducting the first analysis of the microbial community composition. This data package consists of water column measurements (1) using a multi-probe sonde, (2) plutonium isotopes and total concentrations, (3) total organic/inorganic carbon concentrations, (4) trace metals and major ions concentrations, and (6) microbial community composition. Sediment measurements include (1) plutonium isotopes and total concentrations and (2) microbial community composition.For sediment core and porewater, please see other Pond B data package (ess-dive-60d2352a4495472-20200615T203925174).The data in this package will be submitted for peer review in 2023.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Rapid Analytical Methodology for Chloride Molten Salt Reactor Safeguards and Process Monitoring

Technologies that enable near real-time isotopic analysis of advanced molten salt reactor (MSR) fuels are critically needed to safeguard these reactors, increase their operational efficiency, and enable their widespread deployment with confidence. We present a systematic approach to developing near real-time dissolution and chemical isolation of U, Pu, and major fission products from highly radioactive chloride molten salt samples. Chemical yields greater than 95% were observed for both uranium and the lanthanides. Interference reduction enabled the detection and quantification of key diagnostic isotopes (including 112Ag, 147Nd, and 153Sm) that were previously undetectable in the original sample. The results from this initial scoping study lay the foundation for the development of future automated systems that can enable cost-efficient, near-real time chemical separation and analysis of extremely highly radioactive molten salt samples.

38 - RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCL↗
DOE OSTI2020

Materials Data on Ca(BIr)2 by Materials Project

Ca(IrB)2 is alpha Pu-derived structured and crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Ca is bonded in a 10-coordinate geometry to eight equivalent Ir and six equivalent B atoms. There are four shorter (3.05 Å) and four longer (3.29 Å) Ca–Ir bond lengths. There are two shorter (3.00 Å) and four longer (3.15 Å) Ca–B bond lengths. Ir is bonded in a 4-coordinate geometry to four equivalent Ca and four equivalent B atoms. There are two shorter (2.09 Å) and two longer (2.16 Å) Ir–B bond lengths. B is bonded in a 4-coordinate geometry to three equivalent Ca and four equivalent Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Y(BIr)2 by Materials Project

Y(IrB)2 is alpha Pu-derived structured and crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Y is bonded in a 2-coordinate geometry to eight equivalent Ir and six equivalent B atoms. There are four shorter (3.05 Å) and four longer (3.25 Å) Y–Ir bond lengths. There are two shorter (2.97 Å) and four longer (3.15 Å) Y–B bond lengths. Ir is bonded in a 4-coordinate geometry to four equivalent Y and four equivalent B atoms. There are two shorter (2.08 Å) and two longer (2.19 Å) Ir–B bond lengths. B is bonded in a 4-coordinate geometry to three equivalent Y and four equivalent Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nd(BOs)4 by Materials Project

Nd(OsB)4 is alpha Pu-derived structured and crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. Nd2+ is bonded in a 8-coordinate geometry to eight equivalent Os2- atoms. There are four shorter (3.22 Å) and four longer (3.23 Å) Nd–Os bond lengths. Os2- is bonded in a 4-coordinate geometry to two equivalent Nd2+ and four equivalent B+1.50+ atoms. There are a spread of Os–B bond distances ranging from 2.14–2.19 Å. B+1.50+ is bonded in a 4-coordinate geometry to four equivalent Os2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu(BIr)4 by Materials Project

Eu(IrB)4 is alpha Pu-derived structured and crystallizes in the tetragonal P4_2/n space group. The structure is three-dimensional. Eu is bonded in a 4-coordinate geometry to four equivalent B atoms. All Eu–B bond lengths are 2.92 Å. Ir is bonded in a 4-coordinate geometry to four equivalent B atoms. There are a spread of Ir–B bond distances ranging from 2.11–2.17 Å. B is bonded in a 6-coordinate geometry to one Eu, four equivalent Ir, and one B atom. The B–B bond length is 1.87 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu(BIr)2 by Materials Project

Eu(IrB)2 is alpha Pu-derived structured and crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Eu is bonded in a 10-coordinate geometry to eight equivalent Ir and six equivalent B atoms. There are four shorter (3.08 Å) and four longer (3.34 Å) Eu–Ir bond lengths. There are two shorter (3.04 Å) and four longer (3.16 Å) Eu–B bond lengths. Ir is bonded in a 4-coordinate geometry to four equivalent Eu and four equivalent B atoms. There are two shorter (2.10 Å) and two longer (2.17 Å) Ir–B bond lengths. B is bonded in a 4-coordinate geometry to three equivalent Eu and four equivalent Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba7(BIr)12 by Materials Project

Ba7(IrB)12 is alpha Pu-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Ba sites. In the first Ba site, Ba is bonded in a 3-coordinate geometry to one Ir and two equivalent B atoms. The Ba–Ir bond length is 3.14 Å. Both Ba–B bond lengths are 3.15 Å. In the second Ba site, Ba is bonded in a distorted cuboctahedral geometry to six equivalent Ir and six equivalent B atoms. All Ba–Ir bond lengths are 3.58 Å. All Ba–B bond lengths are 3.51 Å. There are two inequivalent Ir sites. In the first Ir site, Ir is bonded in a 4-coordinate geometry to four B atoms. There are two shorter (2.16 Å) and two longer (2.18 Å) Ir–B bond lengths. In the second Ir site, Ir is bonded in a 5-coordinate geometry to two Ba and four B atoms. There are two shorter (2.13 Å) and two longer (2.17 Å) Ir–B bond lengths. There are two inequivalent B sites. In the first B site, B is bonded in a 4-coordinate geometry to three Ba and four Ir atoms. In the second B site, B is bonded in a 5-coordinate geometry to four Ir and one B atom. The B–B bond length is 1.83 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PrSO by Materials Project

PrSO is alpha Pu-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Pr4+ is bonded in a 4-coordinate geometry to two equivalent S2- and four equivalent O2- atoms. Both Pr–S bond lengths are 3.04 Å. There are a spread of Pr–O bond distances ranging from 2.34–2.45 Å. S2- is bonded in a 3-coordinate geometry to two equivalent Pr4+ and one S2- atom. The S–S bond length is 2.10 Å. O2- is bonded to four equivalent Pr4+ atoms to form a mixture of distorted edge and corner-sharing OPr4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(GaPt)2 by Materials Project

Ba(PtGa)2 is alpha Pu-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ba is bonded in a 2-coordinate geometry to eight Pt and nine Ga atoms. There are a spread of Ba–Pt bond distances ranging from 3.32–4.01 Å. There are a spread of Ba–Ga bond distances ranging from 3.44–3.89 Å. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded in a 4-coordinate geometry to four equivalent Ba and four Ga atoms. There are a spread of Pt–Ga bond distances ranging from 2.47–2.56 Å. In the second Pt site, Pt is bonded in a 6-coordinate geometry to four equivalent Ba and four Ga atoms. There are a spread of Pt–Ga bond distances ranging from 2.49–2.59 Å. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a 4-coordinate geometry to four equivalent Ba and four Pt atoms. In the second Ga site, Ga is bonded in a 4-coordinate geometry to five equivalent Ba and four Pt atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H2O by Materials Project

H2O is alpha Pu-like structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of twelve water molecules. there are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. O2- is bonded in a water-like geometry to two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H2O by Materials Project

H2O is alpha Pu-like structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of twelve water molecules. there are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. O2- is bonded in a water-like geometry to two H1+ atoms. Both O–H bond lengths are 1.00 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H2O by Materials Project

H2O is alpha Pu-like structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of twelve water molecules. there are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. O2- is bonded in a water-like geometry to two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Bi24Cl10O31 by Materials Project

Bi24O31Cl10 is alpha Pu-derived structured and crystallizes in the monoclinic P2/c space group. The structure is three-dimensional. there are twelve inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Bi–O bond distances ranging from 2.31–2.72 Å. In the second Bi3+ site, Bi3+ is bonded in a 3-coordinate geometry to three O2- and four Cl1- atoms. There are one shorter (2.11 Å) and two longer (2.15 Å) Bi–O bond lengths. There are a spread of Bi–Cl bond distances ranging from 3.29–3.46 Å. In the third Bi3+ site, Bi3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Bi–O bond distances ranging from 2.30–2.99 Å. In the fourth Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- and three Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.18–2.36 Å. There are a spread of Bi–Cl bond distances ranging from 3.29–3.44 Å. In the fifth Bi3+ site, Bi3+ is bonded in a 5-coordinate geometry to five O2- and one Cl1- atom. There are a spread of Bi–O bond distances ranging from 2.24–2.44 Å. The Bi–Cl bond length is 3.51 Å. In the sixth Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- and four Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.26–2.29 Å. There are a spread of Bi–Cl bond distances ranging from 3.32–3.37 Å. In the seventh Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six O2- and two Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.25–2.69 Å. There are one shorter (3.30 Å) and one longer (3.38 Å) Bi–Cl bond lengths. In the eighth Bi3+ site, Bi3+ is bonded in a 3-coordinate geometry to three O2- and three Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.11–2.16 Å. There are a spread of Bi–Cl bond distances ranging from 3.26–3.50 Å. In the ninth Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six O2- and two Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.23–2.60 Å. There are one shorter (3.26 Å) and one longer (3.44 Å) Bi–Cl bond lengths. In the tenth Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- and four Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.18–2.40 Å. There are a spread of Bi–Cl bond distances ranging from 3.39–3.53 Å. In the eleventh Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- and four Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.24–2.31 Å. There are a spread of Bi–Cl bond distances ranging from 3.25–3.40 Å. In the twelfth Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- and four Cl1- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.33 Å. There are a spread of Bi–Cl bond distances ranging from 3.42–3.54 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Bi3+ atoms to form distorted OBi4 tetrahedra that share corners with three OBi4Cl tetrahedra and edges with four OBi4 tetrahedra. In the second O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the third O2- site, O2- is bonded in a 3-coordinate geometry to four Bi3+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Bi3+ atoms. In the fifth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to three Bi3+ atoms. In the seventh O2- site, O2- is bonded to four Bi3+ and one Cl1- atom to form a mixture of distorted corner and edge-sharing OBi4Cl tetrahedra. The O–Cl bond length is 3.39 Å. In the eighth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Bi3+ and one Cl1- atom. The O–Cl bond length is 3.31 Å. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to four Bi3+ atoms. In the tenth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the eleventh O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to four Bi3+ atoms. In the fourteenth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the fifteenth O2- site, O2- is bonded to four Bi3+ atoms to form a mixture of distorted corner and edge-sharing OBi4 tetrahedra. In the sixteenth O2- site, O2- is bonded in a distorted see-saw-like geometry to four Bi3+ atoms. There are six inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 6-coordinate geometry to six Bi3+ atoms. In the second Cl1- site, Cl1- is bonded in a 8-coordinate geometry to six Bi3+ and two O2- atoms. In the third Cl1- site, Cl1- is bonded in a 2-coordinate geometry to six Bi3+ atoms. In the fourth Cl1- site, Cl1- is bonded in a 4-coordinate geometry to six Bi3+ atoms. In the fifth Cl1- site, Cl1- is bonded in a 7-coordinate geometry to seven Bi3+ atoms. In the sixth Cl1- site, Cl1- is bonded in a 6-coordinate geometry to six Bi3+ atoms.

36 MATERIALS SCIENCE↗