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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Modeling of SRS Aluminum-clad Spent Nuclear Fuel in Standard DOE Sealed Canisters

At the Savannah River Site (SRS), approximately 7 MTHM of aluminum-clad spent nuclear fuel is currently in wet storage at L-basin. A significant portion of this fuel is slated to be dried and sealed in DOE standard canisters for long-term storage. This report will focus on a few fuel types, which should bound all other fuel stored at SRS. These consist of the reference fuel assembly, the MURR fuel and the HFIR fuel. These bound a hypothetical maximum scenario for MTR box fuel, a maximum for decay heat in an assembly, and a maximum for the aluminum surface area, respectively. The geometry for the packages were created from DOE specifications for storage of each of the fuels. As long as the minimum time from reactor discharge to sealed storage is 3 years, then the highest temperatures which occur within the sealed canisters do not exceed 100° C for all scenarios considered here. In the geometry considered, while the HFIR fuel has a large surface area, the packaging configuration leaves large void areas, such that the aluminum surface to free volume ratio is about 30% less than an ATR or MURR packaging configuration.

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DOE OSTI2020

Quantitative Determination of Total Cesium in Savannah River Site (SRS) Tank Waste by Inductively Coupled Plasma Emission Spectroscropy

Utilization of the significant and unique wavelength dynamic range (165 to 1100 nm) available on the Leeman Prodigy Inductively Coupled Plasma Emission Spectroscopy (ICP-ES) allows for quantification of cesium using the emission line 894.347 nm without the potential of Barium interference in nuclear waste samples. Samples are added to a Sodium Peroxide Fusion and Lithium Carbonate buffer in 2% nitric acid solution to increase sensitivity of the easily ionizable (<6 eV) cesium for quantitation to 5 pbb. Through direct comparison of analytical data results, the method is proven to be complementary to the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analysis (LOQ 100 ppt) in support of the Department of Energy’s (DOE) Nuclear Waste Mission.

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DOE OSTI2024

FIU Project1: Chemical Process Alternatives for Radioactive Waste [Slides]

"The U.S. DOE Hanford Site has the largest number of high-level waste (HLW) storage tanks and the largest volume of HLW in the United States. The safe storage, retrieval, treatment, and disposal of approximately 53 million gallons of highly toxic, high-level radioactive waste stored in Hanford’s 177 underground tanks are a national priority. Retrieval and treatment of waste from these tanks pose a considerable challenge. Florida International University has been conducting research on several promising alternative processes and technologies that can be applied to address several technology gaps in the current waste retrieval and conditioning plans. Specifically, FIU has been involved in: the evaluation of non-metallic materials in the waste transfer system, evaluation of alternative HLW instrumentation for in-tank applications and the development of technologies to assist in the inspection of tank bottoms at Hanford."

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DOE OSTI2020

AWCC Simulations

Neutron well counters provide a means to measure fissile mass by detecting coincident neutrons, which is a unique signature to fission. For coincidence counting, mass is determined using a calibration curve established with items that have the same material characteristics. Multiplicity analysis solves the point model equations for mass using known detector parameters. In both cases, mass measurements may exhibit a bias due to item characteristics and should be corrected for. Experiments can be done to estimate bias and material effects, but they require having both the well counter and the material well defined. In pursuit of estimating measurement bias and uncertainty in a High Efficiency Neutron Counter (HENC), an MCNP simulation was matched to measurements performed with an Active Well Coincidence Counter (AWCC) to de ne a neutron source term. The neutron source term will be used to predict measurement performance of similar material types in a HENC.

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DOE OSTI2020

H-Canyon exhaust tunnel LiDAR data request for information review and release

This request is to release LiDAR data files acquired by SRNL R&D Engineering and H-Area Operations and Engineering while performing scans of the interior of the H-Canyon Exhaust tunnel. LiDAR data includes 3-dimensional (3D) point cloud data sets and panoramic digital images of the interior tunnel wall surfaces. Presently two deployments have been completed, the first in November 2019, Fig. 1, and the second in June of 2020. This request is for the release of the data collected during those two deployments. Detailed information on the deployment and data collected can be found in SRS document C-ESR-H-00072, “November 2019 Initial Deployment of LiDAR”. It is planned to perform ongoing scans at approximately 6-month intervals, the purpose of the deployments is to evaluate the usefulness of the data collected to enable quantitative measurements such as tunnel dimensions and rate of surface erosion and as a precursor to a potential deployment of a LiDAR system on the tunnel inspection crawler.

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DOE OSTI2020

November 2019 Initial Deployment of LiDAR in the H-Canyon Exhaust Tunnel

The H-Canyon Exhaust Tunnel (CAEX) structure is periodically inspected under the Structural Integrity Program using camera equipped crawlers or poles to remotely perform visual inspections. To explore the use of enhanced inspection methods a “Proof of Concept” using the Light Detection and Ranging (LiDAR) technology was performed over a 2-day period in November 2019. The purpose of the “Proof of Concept” deployment was to confirm whether a commercially available LiDAR unit could successfully operate and remotely transmit data from the tunnel CAEX environment and whether the data would provide quantitative information to establish baseline measurements. The LiDAR performance requirement was a measurement accuracy of ± 0.25-inches over a 30-foot distance. This report documents the work activities leading to the deployment, the deployment and processing of data, lessons learned from the deployment and the post data processing methods that will be applied to future deployments.

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DOE OSTI2021

Template size and proper overlap detection in Laser Confocal Microscope (LCM) images [Slides]

The LCM has been used to interrogate the inside of hazardous material 3013 storage containers resulting in many LCM images. Joining these images together to create one large image allows one to see features, potential cracking and potential pitting, that extend from one image to another. The images have been found to cover some (5% – 10% at the edges) of the same sample area. This overlap appears to change slightly from image to image so that a global overlap value does not solve the stitching problem. It will be necessary to determine the proper overlap for two adjacent, horizontal or vertical, images. The methodology presented here shows how to estimate the overlap.

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DOE OSTI2022

CAAS-3S Radiation Testing for Y-12 and UPF with Godiva-IV

Goals: 1) Qualify the CAAS-3S system to a mixed-field radiation dose and dose rate, and 2) Extend the Y-12 Shielding MCNP Validation to rad-si. This paper represents the efforts of Y-12 and UPF personnel, and their interpretation of the test results.

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DOE OSTI2023

The Center for Performance and Design of Nuclear Waste Forms and Containers (WastePD) Energy Frontier Research Center (Final Report)

The DOE Office of Environmental Management is responsible for high level nuclear waste that must be safely isolated from humans and the environment for extremely long periods. The waste forms and containers are made of glass, ceramics, and metals. Verified safe disposal requires understanding the fundamental mechanisms of waste form degradation and the design of new waste forms with improved performance, which comprise the goals of the Energy Frontier Research Center known as the Center for the Performance and Design of Nuclear Waste Forms and Containers, WastePD. WastePD was constructed to develop innovative approaches and solutions to those goals through the synergistic interactions of individuals who are experts in the degradation behavior, modeling, and design of glasses, ceramics and metal alloys. WastePD is the first center ever created to address this diverse group of materials in a comprehensive and coordinated manner. The science goals are grouped into three common topics: corrosion mechanisms via advanced characterization, environmental impacts, and materials design. Synergistic interactions in these areas were a key component of WastePD. The fundamental understanding of the degradation mechanisms of the waste forms and containers as well as the development of new materials with improved properties will allow DOE to prevent environmental contamination and to explore totally new repository concepts. WastePD was operational from August 2016 through July 2022, but the DOE support was drastically reduced for the last two years. This final technical report covers the full period of performance. However, much of what was accomplished in the first four years is nicely summarized in a review paper published in 2021, which is appended to this report. Therefore, this final report focuses on the technical findings from the last two years of WastePD activities. Considerable progress was made in the areas of a) the environmental and compositional impacts on the corrosion of borosilicate and aluminosilicate glasses, b) the mechanism of glass corrosion and the structure and evolution of the surface alteration layer, c) the effects of environment and composition on the corrosion of pyrochlore, perovskite, hollandite, and other oxide ceramics, d) the corrosion mechanism of multi-principal element metallic alloys, and e) a new framework for understanding the pitting corrosion of metals.

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DOE OSTI2023

Determination of the uranium content of storage containers filled with waste from Fukushima using cosmic ray data

This report presents the results of an experimental study of cosmic ray tomography aimed at determining the uranium contents of waste containers filled with waste from Fukushima. Data, taken using the Giant Muon Tracker, were obtained on a set of scenes constructed from blocks of polyethylene, concrete, iron, and lead. The data have been provided to Toshiba and have been used to evaluate the composition of scenes using multivariate linear regression.

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DOE OSTI2020

Transient Coupled Chemical-Thermal-Fluid Field Simulation for Sealed Aluminum-clad Spent Nuclear Fuel Storage Canister

As the first step toward developing three-dimensional (3D) multi-physics computational fluid dynamics (CFD) model for unsealed and vented canister storage system, a 3D CFD model coupled with bulk gas radiolysis reactions was developed first for sealed DOE standard canisters filled with inert gas and trace amount of air and water. The workflow for constructing canister-scale 3D CFD models and coupling with gas phase radiolysis reactions were established, which can be readily extended to unsealed, vented canister storage system. This interim milestone report documents the theory of the model, workflow to establish radiolysis reaction network, and initial simulations of the evolutions of thermal fields and hydrogen gas concentrations within sealed DOE standard canisters over long period of time. In addition, a mesh refinement test was done to show that increasing the models mesh refinement had negligible impact upon the temperature profiles.

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DOE OSTI2023

IER-479: Final Design of Low-Temperature TEX Experiments [Slides]

This presentation discusses the final design of low-temperature Thermal Epithermal eXperiments (TEX) experiments. Designed to validate low temperature cross sections and crit safety analyses. The presentation includes discussion on Low-Temp TEX Chamber a Cryostat Chamber capable of cooling between room temp and -40c. Finally, the presentation touches on reactivity via separation where the need to know how the system will behave approaching critical as lifted into annular reflector is analyzed.

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DOE OSTI2020

Complete Documentation of Applicable Regulations and Regulatory Authority for Transportation

This report fulfills the M4 milestone M4MR-20PN0303023, “Complete Documentation of Applicable Regulations and Regulatory Authority for Transportation. Microreactors are very small nuclear reactors with a power output of 20MWe or less and are designed to be factory-built, modular in nature, and highly portable. The objective of this report is to identify and document applicable regulations, the appropriate regulatory authority, and the associated framework for microreactor transport. Sections 2 and 3 of this report summarize U.S. Department of Transportation (DOT) and NRC regulations related to the transportation of Class 7 (radioactive) materials. These sections concentrate on the transport of fissile material packages and Type B packages, which would be most applicable to the transport of a microreactor before and after irradiation. Section 4 summarizes DOE hazardous and radioactive material transportation regulations. Section 5 summarizes U.S. Coast Guard regulations related to the transport of radioactive material. Section 6 discusses state requirements for the permitting of oversize and/or overweight truck shipments. Section 7 presents detailed schedules of requirements for transporting fissile material packages and Type B packages based on NRC and DOT regulations. The schedules are presented in a two-column format, the right column is the regulatory requirement and the left column is the citation of the regulation in which the requirement is found.

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DOE OSTI2020

Particle Size and Density Measurement

This project has developed a miniature gravity settling classifier (flow cell) and flow system that separates slurry particles by settling rate into six different Cuts. The settling rates for particles in each Cut were determined from COMSOL computational fluid dynamics (CFD) modeling of the flow in the flow cell together with particle tracking for particles of differing settling rates. For particles collected in each Cut, the particle concentration and size distribution were measured. The effective particle densities from each Cut are calculated from their respective CFD modeled settling rates using a relationship between the unhindered settling rate, particle size distribution (PSD), and effective density. The particle size and density distribution (PSDD) of the slurry sample is then calculated by combining the size and density distributions determined for the particles collected in each of the settling rate Cuts.

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DOE OSTI2020

Chemical Modeling of ATR Fuel in DOE Standard Canisters with Borated Stainless Steel Corrosion

Road-ready and final disposition packaging configurations for the ATR fuel dictates storage within helium backfilled sealed DOE standard canisters. The packaging configuration for the DOE canisters places 10 ATR elements within a Type 1a basket, and three baskets are loaded within each DOE canister. In order to provide a criticality control mechanism, these stainless baskets are proposed to be built with 1-2 weight percentage of boron. This report seeks to identify effects of corrosion of this basket material over time. The primary reaction found through surveying literature was the oxidation of the iron in steel by water to produce some hydrogen. This reaction was built into the previous chemical model of the DOE canister to assess additional hydrogen and pressure build up over time. Literature for non-borated stainless steel, and carbon steel has shown that irradiation increases the rate of corrosion, and it is assumed a similar effect would occur with borated stainless steel. Due to the wide range of results in literature, and the variation of the corrosion with boron content, a wide range of corrosion rates was tested in the model from 80 nm/yr up to 1800 nm/yr.

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