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At least 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Control Selection for the Neutralization Tank in the Aqueous Recovery System at the Savannah River Plutonium Processing Facility

The Aqueous Recovery System (ARS) at the Savannah River Plutonium Processing Facility (SRPPF) recovers and purifies plutonium (Pu) using aqueous chemistry techniques. The neutralization tanks in the ARS collect the waste streams, containing various impurities and greatly reduced concentrations of Pu, that are produced during aqueous processing. Criticality safety is primarily achieved in the ARS by using geometrically favorable process vessels. However, due to the geometry of neutralization tanks, each tank is administratively limited to no more than 450 g Pu, thus representing the transition from geometry to mass control. To ensure that this mass limit is not exceeded, an administrative control requires taking two samples of any solution to be sent to a neutralization tank. Normal operations are expected to result in less than 50 g Pu in a neutralization tank filled to its capacity of 250 L. Process upsets may cause an inadvertent transfer of up to 1000 g Pu to a neutralization tank, producing a system that is potentially not subcritical for all possible configurations of the tank. To ensure that a neutralization tank remains safety subcritical, passive engineered controls (e.g.changing tank geometry or adding fixed poisons), active engineered controls (e.g. interlocks), and administrative controls (e.g. soluble poisons and valve isolation) were considered and their viability evaluated. Ultimately, the team chose an administrative, dual-valve isolation strategy. This paper will thoroughly discuss the various control strategy options and why many of the options were not feasible for maintaining criticality safety.

Dressman, Phillip M. [Savannah River Nuclear Solut↗
DOE OSTI2025

Use of Captured CO2 for Production of Sustainable Polyurethane Foams in Automotive Applications

Captured CO2 has been investigated as a feedstock for the production of polyurethane (PU) foams for automotive applications. Previous work has shown successful incorporation of CO2 into polyols via three distinct reaction pathways. These CO2-derived polyols, as well as several commercially available polyols with varying CO2 content, were used to produce PU foams for automotive seating and NVH (noise, vibration, and harshness) applications. Foam formulations were optimized to maximize sustainable content while maintaining manufacturability constraints and performance requirements for each end use application. PU foams were first formulated at lab scale to confirm free rise and molded foam properties, then scaled up to pilot and industrial scales to evaluate production manufacturing feasibility. Finally, CO2-derived foams were used to produce molded components for end use product validation. Life cycle assessment (LCA) was used to quantify the environmental impact of using captured CO2 and bio-renewable content into polyols and PU foams through the metrics of global warming potential and embodied energy. Tradeoffs among environmental impacts, energy usage, manufacturability, and PU foam performance from the incorporation of CO2 and bio-renewable content will be discussed.

Lee, Ellen [Ford Motor Company]↗
DOE OSTI2020

Materials Data on Pu2Si4Tc3 by Materials Project

Pu2Tc3Si4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Pu+4.50+ is bonded in a 1-coordinate geometry to four Tc3- atoms. There are a spread of Pu–Tc bond distances ranging from 2.84–3.20 Å. There are two inequivalent Tc3- sites. In the first Tc3- site, Tc3- is bonded in a 12-coordinate geometry to four equivalent Pu+4.50+ and six Si atoms. There are a spread of Tc–Si bond distances ranging from 2.50–2.52 Å. In the second Tc3- site, Tc3- is bonded in a 7-coordinate geometry to two equivalent Pu+4.50+ and five Si atoms. There are a spread of Tc–Si bond distances ranging from 2.42–2.50 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 6-coordinate geometry to four Tc3- atoms. In the second Si site, Si is bonded in a 4-coordinate geometry to four Tc3- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuNi5 by Materials Project

PuNi5 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Pu is bonded in a 6-coordinate geometry to eighteen Ni atoms. There are six shorter (2.83 Å) and twelve longer (3.15 Å) Pu–Ni bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to three equivalent Pu and six equivalent Ni atoms. All Ni–Ni bond lengths are 2.43 Å. In the second Ni site, Ni is bonded to four equivalent Pu and eight Ni atoms to form a mixture of edge, face, and corner-sharing NiPu4Ni8 cuboctahedra. All Ni–Ni bond lengths are 2.45 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuH18C3S3(O2F)9 by Materials Project

Pu(H2O)9(CF3)3(SO3)3 crystallizes in the hexagonal P6_3/m space group. The structure is zero-dimensional and consists of six fluoroform molecules, six sulfur trioxide molecules, and two Pu(H2O)9 clusters. In each Pu(H2O)9 cluster, Pu5+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are six shorter (2.50 Å) and three longer (2.58 Å) Pu–O bond lengths. There are three 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 0.98 Å. In the second 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 third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Pu5+ and two equivalent H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Pu5+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuGa6 by Materials Project

PuGa6 crystallizes in the tetragonal P4/nbm space group. The structure is three-dimensional. Pu is bonded to twelve Ga atoms to form a mixture of edge and face-sharing PuGa12 cuboctahedra. There are four shorter (3.10 Å) and eight longer (3.18 Å) Pu–Ga bond lengths. There are two inequivalent Ga sites. In the first Ga site, Ga is bonded in a 4-coordinate geometry to one Pu and three Ga atoms. There are one shorter (2.56 Å) and two longer (2.62 Å) Ga–Ga bond lengths. In the second Ga site, Ga is bonded in a 9-coordinate geometry to four equivalent Pu and five Ga atoms. The Ga–Ga bond length is 2.41 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pu2O3 by Materials Project

Pu2O3 is Spinel-derived structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are four inequivalent Pu3+ sites. In the first Pu3+ site, Pu3+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing PuO6 octahedra. The corner-sharing octahedra tilt angles range from 57–58°. There are a spread of Pu–O bond distances ranging from 2.29–2.41 Å. In the second Pu3+ site, Pu3+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing PuO6 octahedra. The corner-sharing octahedra tilt angles range from 57–58°. There are a spread of Pu–O bond distances ranging from 2.30–2.40 Å. In the third Pu3+ site, Pu3+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing PuO6 octahedra. The corner-sharing octahedral tilt angles are 58°. There are four shorter (2.34 Å) and two longer (2.35 Å) Pu–O bond lengths. In the fourth Pu3+ site, Pu3+ is bonded to six equivalent O2- atoms to form a mixture of distorted edge and corner-sharing PuO6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Pu–O bond lengths are 2.32 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Pu3+ atoms to form a mixture of edge and corner-sharing OPu4 tetrahedra. In the second O2- site, O2- is bonded to four Pu3+ atoms to form a mixture of edge and corner-sharing OPu4 tetrahedra. In the third O2- site, O2- is bonded to four Pu3+ atoms to form a mixture of edge and corner-sharing OPu4 tetrahedra. In the fourth O2- site, O2- is bonded to four Pu3+ atoms to form a mixture of edge and corner-sharing OPu4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuPd3 by Materials Project

PuPd3 is Uranium Silicide-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pu is bonded to twelve Pd atoms to form a mixture of corner, edge, and face-sharing PuPd12 cuboctahedra. All Pu–Pd bond lengths are 2.93 Å. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded to four equivalent Pu atoms to form a mixture of distorted corner and edge-sharing PdPu4 cuboctahedra. In the second Pd site, Pd is bonded in a distorted square co-planar geometry to four equivalent Pu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuBi3 by Materials Project

PuBi3 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pu is bonded to twelve Bi atoms to form PuBi12 cuboctahedra that share corners with four equivalent PuBi12 cuboctahedra, edges with eight equivalent PuBi12 cuboctahedra, edges with sixteen equivalent BiPu4Bi8 cuboctahedra, faces with four equivalent PuBi12 cuboctahedra, and faces with eight equivalent BiPu4Bi8 cuboctahedra. There are four shorter (3.26 Å) and eight longer (3.59 Å) Pu–Bi bond lengths. There are two inequivalent Bi sites. In the first Bi site, Bi is bonded to four equivalent Pu and eight Bi atoms to form distorted BiPu4Bi8 cuboctahedra that share corners with twelve equivalent BiPu4Bi8 cuboctahedra, edges with eight equivalent PuBi12 cuboctahedra, edges with eight equivalent BiPu4Bi8 cuboctahedra, faces with four equivalent PuBi12 cuboctahedra, and faces with ten equivalent BiPu4Bi8 cuboctahedra. There are four shorter (3.26 Å) and four longer (3.59 Å) Bi–Bi bond lengths. In the second Bi site, Bi is bonded in a square co-planar geometry to four equivalent Pu and eight equivalent Bi atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuHg3 by Materials Project

PuHg3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pu is bonded in a distorted body-centered cubic geometry to fourteen Hg atoms. There are eight shorter (3.19 Å) and six longer (3.68 Å) Pu–Hg bond lengths. There are two inequivalent Hg sites. In the first Hg site, Hg is bonded in a distorted body-centered cubic geometry to four equivalent Pu and four equivalent Hg atoms. All Hg–Hg bond lengths are 3.19 Å. In the second Hg site, Hg is bonded in a 8-coordinate geometry to six equivalent Pu and eight equivalent Hg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuSn2 by Materials Project

PuSn2 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Pu is bonded in a 10-coordinate geometry to ten Sn atoms. There are a spread of Pu–Sn bond distances ranging from 3.19–3.40 Å. There are two inequivalent Sn sites. In the first Sn site, Sn is bonded in a distorted square co-planar geometry to four equivalent Pu atoms. In the second Sn site, Sn is bonded in a 12-coordinate geometry to six equivalent Pu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuAg3 by Materials Project

PuAg3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pu is bonded in a distorted body-centered cubic geometry to fourteen Ag atoms. There are eight shorter (3.07 Å) and six longer (3.54 Å) Pu–Ag bond lengths. There are two inequivalent Ag sites. In the first Ag site, Ag is bonded to four equivalent Pu and four equivalent Ag atoms to form a mixture of distorted edge, face, and corner-sharing AgPu4Ag4 tetrahedra. All Ag–Ag bond lengths are 3.07 Å. In the second Ag site, Ag is bonded in a 8-coordinate geometry to six equivalent Pu and eight equivalent Ag atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuIn7Pt2 by Materials Project

PuPt2In7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pu is bonded to twelve In atoms to form a mixture of corner and face-sharing PuIn12 cuboctahedra. There are four shorter (3.20 Å) and eight longer (3.32 Å) Pu–In bond lengths. Pt is bonded in a body-centered cubic geometry to eight In atoms. There are four shorter (2.76 Å) and four longer (2.82 Å) Pt–In bond lengths. There are three inequivalent In sites. In the first In site, In is bonded in a distorted square co-planar geometry to four equivalent Pu atoms. In the second In site, In is bonded to four equivalent Pt atoms to form a mixture of corner and edge-sharing InPt4 tetrahedra. In the third In site, In is bonded in a 2-coordinate geometry to two equivalent Pu and two equivalent Pt atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuAl2Pd5 by Materials Project

PuPd5Al2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pu is bonded to twelve Pd atoms to form a mixture of corner and face-sharing PuPd12 cuboctahedra. There are four shorter (2.95 Å) and eight longer (3.03 Å) Pu–Pd bond lengths. There are two inequivalent Pd sites. In the first Pd site, Pd is bonded in a distorted square co-planar geometry to four equivalent Pu atoms. In the second Pd site, Pd is bonded in a 6-coordinate geometry to two equivalent Pu and four equivalent Al atoms. There are two shorter (2.59 Å) and two longer (2.63 Å) Pd–Al bond lengths. Al is bonded in a body-centered cubic geometry to eight equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuPb2 by Materials Project

PuPb2 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Pu is bonded in a 10-coordinate geometry to ten Pb atoms. There are a spread of Pu–Pb bond distances ranging from 3.37–3.48 Å. There are two inequivalent Pb sites. In the first Pb site, Pb is bonded in a distorted rectangular see-saw-like geometry to four equivalent Pu atoms. In the second Pb site, Pb is bonded in a 12-coordinate geometry to six equivalent Pu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PuPa3 by Materials Project

PuPa3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pu is bonded to twelve Pa atoms to form PuPa12 cuboctahedra that share corners with four equivalent PuPa12 cuboctahedra, corners with eight equivalent PaPu4Pa8 cuboctahedra, edges with eight equivalent PuPa12 cuboctahedra, edges with sixteen equivalent PaPu4Pa8 cuboctahedra, faces with four equivalent PuPa12 cuboctahedra, and faces with fourteen PaPu4Pa8 cuboctahedra. There are four shorter (3.20 Å) and eight longer (3.22 Å) Pu–Pa bond lengths. There are two inequivalent Pa sites. In the first Pa site, Pa is bonded to four equivalent Pu and eight Pa atoms to form PaPu4Pa8 cuboctahedra that share corners with twelve equivalent PaPu4Pa8 cuboctahedra, edges with eight equivalent PuPa12 cuboctahedra, edges with sixteen PaPu4Pa8 cuboctahedra, faces with four equivalent PuPa12 cuboctahedra, and faces with fourteen PaPu4Pa8 cuboctahedra. There are four shorter (3.20 Å) and four longer (3.22 Å) Pa–Pa bond lengths. In the second Pa site, Pa is bonded to four equivalent Pu and eight equivalent Pa atoms to form PaPu4Pa8 cuboctahedra that share corners with four equivalent PaPu4Pa8 cuboctahedra, corners with eight equivalent PuPa12 cuboctahedra, edges with twenty-four PaPu4Pa8 cuboctahedra, faces with six equivalent PuPa12 cuboctahedra, and faces with twelve PaPu4Pa8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Lu3Pu by Materials Project

PuLu3 is Copper-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pu is bonded to twelve Lu atoms to form PuLu12 cuboctahedra that share corners with four equivalent PuLu12 cuboctahedra, corners with eight equivalent LuLu8Pu4 cuboctahedra, edges with eight equivalent PuLu12 cuboctahedra, edges with sixteen equivalent LuLu8Pu4 cuboctahedra, faces with four equivalent PuLu12 cuboctahedra, and faces with fourteen LuLu8Pu4 cuboctahedra. There are eight shorter (3.30 Å) and four longer (3.31 Å) Pu–Lu bond lengths. There are two inequivalent Lu sites. In the first Lu site, Lu is bonded to four equivalent Pu and eight Lu atoms to form LuLu8Pu4 cuboctahedra that share corners with twelve equivalent LuLu8Pu4 cuboctahedra, edges with eight equivalent PuLu12 cuboctahedra, edges with sixteen LuLu8Pu4 cuboctahedra, faces with four equivalent PuLu12 cuboctahedra, and faces with fourteen LuLu8Pu4 cuboctahedra. There are four shorter (3.30 Å) and four longer (3.31 Å) Lu–Lu bond lengths. In the second Lu site, Lu is bonded to four equivalent Pu and eight equivalent Lu atoms to form LuLu8Pu4 cuboctahedra that share corners with four equivalent LuLu8Pu4 cuboctahedra, corners with eight equivalent PuLu12 cuboctahedra, edges with twenty-four LuLu8Pu4 cuboctahedra, faces with six equivalent PuLu12 cuboctahedra, and faces with twelve LuLu8Pu4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Strategies for thorium fuel cycle transition in the SD-TMSR

Liquid-fueled Molten Salt Reactor (MSR) systems represent advances in safety, economics, and sustainability. The MSR has been designed to operate with a Th/ 233 U fuel cycle with 233 U used as startup fissile material. Since 233 U does not exist in nature, we must examine other available fissile materials to start up these reactor concepts. This work investigates the fuel cycle and neutronics performance of the Single-fluid Double-zone Thorium-based Molten Salt Reactor (SD-TMSR) with different fissile material loadings at startup: High Assay Low Enriched Uranium (HALEU) (19.79%), Pu mixed with HALEU (19.79%), reactor-grade Pu (a mixture of Pu isotopes chemically extracted from Pressurized Water Reactor (PWR) spent nuclear fuel (SNF) with 33 GW d/tHM burnup), transuranic elements (TRU) from Light Water Reactor (LWR) SNF, and 233 U. The MSR burnup routine provided by SERPENT-2 is used to simulate the online reprocessing and refueling in the SD-TMSR. The effective multiplication factor, fuel salt composition evolution, and net production of 233 U are studied in the present work. Additionally, the neutron spectrum shift during the reactor operation is calculated. The results show that the continuous flow of reactorgrade Pu helps transition to the thorium fuel cycle within a relatively short time (≈ 4.5 years) compared to 26 years for 233 U startup fuel. Finally, using TRU as the initial fuel materials offers the possibility of operating the SD-TMSR for an extended period of time (≈ 40 years) without any external feed of 233 U.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗