Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 412

Full-Text Articles in Engineering

Development And Application Of Discrete Element Models For Granular Materials - From Rigid Spheres To Complex-Shaped Flexible Particles With Breakage, Zakia Tasnim May 2024

Development And Application Of Discrete Element Models For Granular Materials - From Rigid Spheres To Complex-Shaped Flexible Particles With Breakage, Zakia Tasnim

All Dissertations

Granular materials, which can range from nanometers to centimeters, are widely encountered as particles or powders in nature and in engineered systems. Some examples of granular materials include sands, gravels, biomass feedstocks, rice grains, pharmaceutical pills, glass beads, and lunar or martian regolith simulants. The attributes of and the interactions between constituent particles dictate the bulk mechanical properties and behavior of granular materials. The discrete element method (DEM), a particle-based modeling technique, has become a useful numerical tool for modeling the bulk behavior (such as mechanical, flow, and breakage behavior) of granular materials, where interactions between the granular materials' individual …


Evacuation Of Students With Intellectual Disability In Building Fires: A Three-Part Methodology, Haley Hostetter May 2024

Evacuation Of Students With Intellectual Disability In Building Fires: A Three-Part Methodology, Haley Hostetter

All Dissertations

People with disabilities are one of the most vulnerable groups in building fires. Despite this, they have traditionally been overlooked by fire evacuation researchers. This is perhaps the most alarming for the group with Intellectual Disability when given their present statistics for fire involvement, injuries, and death. Annually, people with mental disabilities are involved in 1700 home fires, resulting in 39 fatalities and 122 injuries per 1000 fires. Additionally, 40% of these fires were started intentionally by people with mental disabilities. When combined with their high fire risk, the lack of evacuation research focused on people with Intellectual Disability shows …


Development And Evaluation Of An Arsenic Transport Model For The Maurice River Watershed, Christina Eddleman May 2024

Development And Evaluation Of An Arsenic Transport Model For The Maurice River Watershed, Christina Eddleman

All Theses

For many Superfund sites across the United States, arsenic is one of the most common contaminants of concern that must be cleaned up to protect human and environmental health. Past research and health studies have documented the harmful effects of inorganic arsenic on humans and the environment but selecting an appropriate remediation plan depends on several site-specific factors at each Superfund site. To assist in determining an appropriate remediation plan, sediment and contaminant transport models have been used to simulate the transport of arsenic and other contaminants of concern at contaminated sites to, e.g., make relative comparisons of the efficacy …


Analytical And Experimental Studies To Support Codification Of Lightweight Grout For Masonry Design, Cooper Banks May 2024

Analytical And Experimental Studies To Support Codification Of Lightweight Grout For Masonry Design, Cooper Banks

All Theses

Lightweight (LW) aggregates have many potential benefits in masonry construction including minimizing mass, improving thermal performance, and reducing the potential for shrinkage cracking via internal curing. The current masonry design standard, TMS 402/602-22, permits lightweight aggregate in the production of concrete masonry units (CMU), but there has been insufficient testing of masonry assemblies to permit designing with LW grout. Shrestha et al. characterized LW grouts bond to reinforcement, shear strength, tension and shear pullout behavior of anchors and proposed possible reduction factors for design. Hiner characterized the flexural bond strength LW grouted masonry assemblies and proposed possible reduction factors for …


Quantifying Hurricane Effects On Housing: Evaluating Damage, Loss, And Shelter Demands Using Historical And Simulated Storm Tracks, Adish Deep Shakya May 2024

Quantifying Hurricane Effects On Housing: Evaluating Damage, Loss, And Shelter Demands Using Historical And Simulated Storm Tracks, Adish Deep Shakya

All Theses

This research introduces an advanced framework which employs parametric wind field models for peak wind speeds, and building fragility curves, loss functions, and demographic data to estimate for estimating housing damage and loss. The uninhabitable units immediate displaced households, short-term and long-term shelter need households are determined. with a particular focus on those eligible for FEMA assistance. The framework's validity is reinforced by a high correlation in the analysis of recent hurricane events between estimated numbers of displaced households and actual FEMA aid recipients, where FEMA aids about 20-60% of the predicted long-term displaced households. A novel application of the …


Dynamics Of Link Importance Across Flood Disaster Phases And Flood Impacts On Operation Of An Industry, Navin Bhatta May 2024

Dynamics Of Link Importance Across Flood Disaster Phases And Flood Impacts On Operation Of An Industry, Navin Bhatta

All Theses

Transportation damage and disruptions will become increasingly common as the frequency of floods increases due to climate change. Given the size and cost of the transportation network construction, communities' mitigation measures should be supported by evaluations that cover both normal and disaster management phases. This thesis examines the criticality of road segments in the normal, flood response, and recovery phases, considering the effects on emergency services, healthcare, industry, education, recreation, and transit and analyses that whether a flood disrupts the operational trips of a company in Anderson County, South Carolina. A 100-year event and a 500-year flood event provides context …


Engineering Sustainable Bridge Deck Rehabilitation: Evaluating Mechanical And Electro-Chemical Properties Of Rapid-Set Patching Materials And Their Influence On Repair Durability, James Roberts May 2024

Engineering Sustainable Bridge Deck Rehabilitation: Evaluating Mechanical And Electro-Chemical Properties Of Rapid-Set Patching Materials And Their Influence On Repair Durability, James Roberts

All Theses

As the state of the US infrastructure continues to deteriorate over time, a prominent issue especially in the field of reinforced concrete structures has been the ability to properly rehabilitate and extend the design service life of these structures. A majority of our existing reinforced concrete bridges were built in the construction boom during the 60’s, 70’s and 80’s, and were originally designed with a service life of approximately 50 years, thus showing that many structures are close to or have already exceeded their intended service life. Additionally, with a poor history of government infrastructure funding, it is seen to …


Evaluating Company Culture Of Roofing Contracting Companies To Attract And Retain Women In The Industry, Gopika Viswanathan May 2024

Evaluating Company Culture Of Roofing Contracting Companies To Attract And Retain Women In The Industry, Gopika Viswanathan

All Theses

The US construction industry, similar to many other industries, has a low representation of women. This difference is even more pronounced in construction trades, such as the roofing industry. The admission of more women into the industry is important to address workforce shortage issues that the industry is facing. Company culture has been cited as one of the primary reasons why women choose not to enter the industry or face barriers during their careers. The main objective of this study was to evaluate the company culture of roofing companies through factors identified by literature and by women and companies in …


The Development Of A Convenient And Consistent Methodology For Flight Proficiency To Certify Multi-Rotor Uas Pilots For State Departments Of Transportation, Colin Dees May 2024

The Development Of A Convenient And Consistent Methodology For Flight Proficiency To Certify Multi-Rotor Uas Pilots For State Departments Of Transportation, Colin Dees

All Dissertations

To fly an unmanned aircraft system (UAS), commonly referred to as a “drone,” the Federal Aviation Administration (FAA) requires pilots to pass a knowledge test. There is no requirement at the state or federal level for drone operators to demonstrate the ability to operate a UAS. The National Institute of Science and Technology (NIST) has created an exam for public and private entities to assess basic UAS flight proficiency. It is the only nationally recognized flight proficiency protocol. NIST does not provide a scoring recommendation and leaves it to the user to determine the minimum criteria to pass. There is …


Laboratory Evaluation Of Remediation Alternatives For Groundwater At The Lane Street Superfund Site, Alyssa Costello May 2024

Laboratory Evaluation Of Remediation Alternatives For Groundwater At The Lane Street Superfund Site, Alyssa Costello

All Theses

At the Lane Street Groundwater Contamination Superfund site in Elkhart, Indiana, which includes industrial, commercial, and residential properties, a plume of contaminated groundwater was identified that requires remediation. The plume is chiefly composed of trichloroethylene (TCE) and has impacted residents’ drinking water. A microcosm study was performed to evaluate the potential of various treatment methods to remediate the Lane Street Superfund Site groundwater. The objectives of this microcosm study are to evaluate the potential for biostimulation, bioaugmentation, and abiotic degradation for implementation at this Site and to evaluate toxicity factors that have precluded natural degradation of the site contaminants. The …


Influence Of Photoreactor Design Parameters On The Performance Of Ultraviolet Light-Induced Degradation Of Per-And Polyfluoroalkyl Substances By Bismuth Oxy Hydroxy Phosphate And Hexagonal Boron Nitride Photocatalystsinfluence Of Photoreactor Design Parameters On The Performance Of Ultraviolet Light-Induced Degradation Of Per-And Polyfluoroalkyl Substances By Bismuth Oxy Hydroxy Phosphate And Hexagonal Boron Nitride Photocatalysts, Mojtaba Qanbarzadeh Dec 2023

Influence Of Photoreactor Design Parameters On The Performance Of Ultraviolet Light-Induced Degradation Of Per-And Polyfluoroalkyl Substances By Bismuth Oxy Hydroxy Phosphate And Hexagonal Boron Nitride Photocatalystsinfluence Of Photoreactor Design Parameters On The Performance Of Ultraviolet Light-Induced Degradation Of Per-And Polyfluoroalkyl Substances By Bismuth Oxy Hydroxy Phosphate And Hexagonal Boron Nitride Photocatalysts, Mojtaba Qanbarzadeh

All Dissertations

The main objective of this study is to evaluate the practical applicability of heterogeneous photocatalysis technology powered by ultraviolet (UV) photons for the degradation of per and -polyfluoroalkyl substances (PFAS) in contaminated groundwater samples. For this purpose, bismuth oxyhydroxy phosphate (BOHP) and hexagonal boron nitride (hBN) were utilized as the main photocatalysts in slurry photodegradation systems. BOHP (Bi3O(OH)(PO4)2) is a wide bandgap semiconductor with high activity for degrading long-chain perfluorocarboxylic acids (PFCAs) in mild operational conditions. Boron nitride (BN) is another wide bandgap semiconductor material that was used in this study due to its …


Feasibility Of Using High-Alkali Natural Pozzolans And Reclaimed Fly Ash As Alternative Supplementary Cementitious Materials In Concrete, Weiqi Wang Dec 2023

Feasibility Of Using High-Alkali Natural Pozzolans And Reclaimed Fly Ash As Alternative Supplementary Cementitious Materials In Concrete, Weiqi Wang

All Dissertations

Due to the shortage of supplementary cementitious materials (SCMs) in the concrete industry, it is necessary to seek a new alternative. This study evaluates the feasibility of high-alkali SCMs, which were not recommended previously due to potentially exacerbating alkali-silica reaction (ASR) in concrete. The study addresses theSCMs’ ASR mitigation performance, evaluated by ASTM C1567, C1293, and AASHTO T380. Other concrete durability tests, including ASTM C596 drying shrinkage test, ASTM C1012 sulfate resistance test, and ASTM C1202 rapid chloride ions penetration test, were also conducted in this study. The ASTM C311 strength activity index test, thermal gravimetric analysis (TGA), and ASTM …


Nanobubble Technology For The Removal Of Mib And Geosmin From Drinking Water, Meryem Soyluoglu Dec 2023

Nanobubble Technology For The Removal Of Mib And Geosmin From Drinking Water, Meryem Soyluoglu

All Dissertations

The presence of taste and odor (T&O) compounds in drinking water has been historically a major challenge for water utilities. They are difficult to remove using conventional water treatment processes, a combination of coagulation, flocculation, sedimentation, filtration, and chlorination. However, activated carbon (AC) adsorption, advanced oxidation processes, and biofiltration can be effective. The seasonal nature of T&O events makes it difficult to justify installing dedicated treatment technologies. Additionally, incorporating these technologies into existing water treatment plants can be expensive and require significant upgrades. Therefore, water utilities are always interested in exploring new approaches to minimize the occurrence and removal of …


Development Of Scope Of Services For Procurement Of Professional Consultant Services On Transportation Projects – A Study Of South Carolina Department Of Transportation, Ajay Jadhav Dec 2023

Development Of Scope Of Services For Procurement Of Professional Consultant Services On Transportation Projects – A Study Of South Carolina Department Of Transportation, Ajay Jadhav

All Dissertations

Project Scoping Process (PSP) is one of the significant steps that starts at the very beginning of the project life cycle. During project initiation phase, project scoping is kicked off which includes documenting a list of project-specific goals, deliverables, tasks, costs, and deadlines. The scoping phase duration depends on the project complexity and involves various stakeholders, establishing team, confirming the project purpose and need, initiating the environmental revie process, determining the level of environmental documentation and permit requirements, conducting survey, identifying project risks and tools to mitigate them, and evaluating public involvement strategies. A well-defined PSP is therefore essential for …


Effect Of Latex Modified Concrete Overlays With Reduced Surface Preparation On The Load Distribution And Flexural Strength Of Channel Girders, Samuel Dodd Dec 2023

Effect Of Latex Modified Concrete Overlays With Reduced Surface Preparation On The Load Distribution And Flexural Strength Of Channel Girders, Samuel Dodd

All Theses

This thesis investigates the use of a Latex Modified Concrete (LMC) overlay to increase the strength of prestressed channel girders and enhance their ability to distribute load. The research conducted in this thesis involved material testing of several different LMC mixes and flexural testing of an LMC overlay and girder system. The material testing was used to determine a reasonable LMC mix design and surface preparation method to be used for the overlay. Based on material testing it was concluded that a rapid-set mix and pressure washing of the girder surfaces were a reasonable mix design and surface preparation for …


Generative Neural Network-Based Defense Methods Against Cyberattacks For Connected And Autonomous Vehicles, M Sabbir Salek Aug 2023

Generative Neural Network-Based Defense Methods Against Cyberattacks For Connected And Autonomous Vehicles, M Sabbir Salek

All Dissertations

The rapid advancement of communication and artificial intelligence technologies is propelling the development of connected and autonomous vehicles (CAVs), revolutionizing the transportation landscape. However, increased connectivity and automation also present heightened potential for cyber threats. Recently, the emergence of generative neural networks (NNs) has unveiled a myriad of opportunities for complementing CAV applications, including generative NN-based cybersecurity measures to protect the CAVs in a transportation cyber-physical system (TCPS) from known and unknown cyberattacks. The goal of this dissertation is to explore the utility of the generative NNs for devising cyberattack detection and mitigation strategies for CAVs. To this end, the …


Impact Of Granular Activated Carbon On In-Situ Reductive Dechlorination Of Chlorinated Solvents, Reagan Gregory Aug 2023

Impact Of Granular Activated Carbon On In-Situ Reductive Dechlorination Of Chlorinated Solvents, Reagan Gregory

All Theses

Treatment of chlorinated solvent-contaminated aquifers with in-situ activated carbon offers a simple yet cost-effective treatment opportunity, yet the interactions between activated carbon and the chlorinated solvents and their daughter products are not well understood.

The objective of this research is to demonstrate the impacts of in situ activated carbon on complete reductive dechlorination of chlorinated solvents in contaminated aquifer material with mixed dehalogenating cultures. This research seeks to characterize the sorption of trichloroethene and its daughter products cis-dichloroethene, vinyl chloride, and ethene to granular activated carbon and how that sorption relates to the removal of trichloroethene from contaminated material in …


Understanding The Hydromechanical Effects Of Extreme Events To Improve The Performance Of Infrastructure Foundations, Siddharth Marathe Aug 2023

Understanding The Hydromechanical Effects Of Extreme Events To Improve The Performance Of Infrastructure Foundations, Siddharth Marathe

All Dissertations

Extreme hydroclimatic events like heavy rainfall, flooding, and prolonged drought can potentially cause the failure of infrastructure foundations, leading to socio-economic losses. The objective of this dissertation is to understand the deformation and bearing capacity behavior of drilled shafts subjected to extreme hydroclimatic events, including heavy rainfall, prolonged drought, and earthquake. The Finite Element Method (FEM) results show that during rainfall, the drilled shaft settled caused by a decrease in the porewater pressure in the sand leading to a decrease in the axial bearing capacity. The axial force variation from an experimental investigation showed good agreement with the FEM. The …


Improved Vehicle-Bridge Interaction Modeling And Automation Of Bridge System Identification Techniques, Omar Abuodeh Aug 2023

Improved Vehicle-Bridge Interaction Modeling And Automation Of Bridge System Identification Techniques, Omar Abuodeh

All Dissertations

The Federal Highway Administration (FHWA) recognizes the necessity for cost-effective and practical system identification (SI) techniques within structural health monitoring (SHM) frameworks for asset management applications. Indirect health monitoring (IHM), a promising SHM approach, utilizes accelerometer-equipped vehicles to measure bridge modal properties (e.g., natural frequencies, damping ratios, mode shapes) through bridge vibration data to assess the bridge's condition. However, engineers and researchers often encounter noise from road roughness, environmental factors, and vehicular components in collected vehicle signals. This noise contaminates the vehicle signal with spurious modes corresponding to stochastic frequencies, impacting damage monitoring assessments. Thus, an efficient and reliable SI …


High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman Aug 2023

High-Energy Storm Events And Their Impacts On Carbon Storage In Tidal Wetlands Of South Carolina, Gavin Gleasman

All Dissertations

Atmospheric carbon dioxide (CO2) concentrations have been increasing at an accelerating rate for the past two centuries, profoundly impacting global climate change. Atmospheric CO2 concentrations are influenced by the global carbon cycle through physical and biogeochemical pathways. Tidal wetland environments play a vital role in the global carbon cycle by offsetting atmospheric CO2 concentrations through their natural physiochemical processes of high autotrophic productivity, allochthonous organic matter deposition, anoxic soils, and continuous accretion which promotes carbon sequestration with long-term storage at the land-ocean margin. The Intergovernmental Panel on Climate Change (IPCC) and United States Global Change Research …


Effect Of Transverse Post-Tensioning On Moment Distribution Between Channel Girders, William Eubanks Aug 2023

Effect Of Transverse Post-Tensioning On Moment Distribution Between Channel Girders, William Eubanks

All Theses

This thesis investigates the strength of prestressed concrete channel girders used

in bridges in South Carolina and how to improve their load distribution. The specimens

are 30 feet in length, 33 inches wide and 17 inches deep. South Carolina has 377 bridges

containing prestressed concrete channel girders and many of these bridges received a

poor load rating in a recent load rating project conducted by the South Carolina

Department of Transportation (SCDOT). The research included flexural testing of seven

individual channel girders and load distribution tests of three transversely post-tensioned

channel girders. Individual flexural testing was done to determine the …


Vibration Fatigue Of Leaded Solder Joint Interconnects For Pcb Electronics, John Crowder Aug 2023

Vibration Fatigue Of Leaded Solder Joint Interconnects For Pcb Electronics, John Crowder

All Theses

With the increasing prevalence of electronic equipment worldwide, there is also a decrease in the size of the components on their printed circuit boards (PCBs), leading to an increase in the density of these components. A significant amount of failure in electronic equipment is vibration fatigue of solder joints and their attachments. However, the complexity of these PCBs and their components has made finite element modeling (FEM) more complex, adding considerable time to create and analyze a model.

This paper aims to provide a literature review for the vibration fatigue of leaded solder components, create a test setup, and validate …


Investigation Into The Load Transfer Mechanism Of Trees To Develop An Innovative Foundation Configuration Using 3d Finite Element Modeling, Kaleb Boland Aug 2023

Investigation Into The Load Transfer Mechanism Of Trees To Develop An Innovative Foundation Configuration Using 3d Finite Element Modeling, Kaleb Boland

All Theses

This study was inspired by a tree’s reliance on its root system that enables it to withstand a natural disaster, such as an extreme hydroclimatic event or hurricane. This curiosity has led to an investigation into what makes this possible, developing a new and innovative foundation configuration for infrastructure systems, and a new possible construction material and method. This study provides results on a material that does not have conventional testing procedures or standards: a tree root. The trees studied are common to the upstate of South Carolina, which are Pine, Sweetgum, and White Oak. According to the results, on …


Evaluating The Feasibility Of Using Strain Measured During Sinusoidal Rate Pumping Tests To Characterize An Aquifer, Riley Blais Aug 2023

Evaluating The Feasibility Of Using Strain Measured During Sinusoidal Rate Pumping Tests To Characterize An Aquifer, Riley Blais

All Theses

Pumping tests with sinusoidal variation in pumping rate have been proposed as a method for improving aquifer characterization. These tests can interrogate a larger aquifer volume than slug tests and they can be more sensitive to small variations in drawdown. Current methods of using sinusoidal variations of rate are based on measuring pressure signals from the reservoir or aquifer, which requires access to monitoring wells. An alternative approach has been developed that measures the strain in the vadose zone instead of pressure in the reservoir. An instrument has been developed at Clemson University that can measure small strains using optical …


Experimental Investigation Of The Long-Term Bending Deflection And Creep Performance Of Cross-Laminated Timber (Clt), Aaron Desantis Aug 2023

Experimental Investigation Of The Long-Term Bending Deflection And Creep Performance Of Cross-Laminated Timber (Clt), Aaron Desantis

All Theses

Rising popularity in mass timber construction for residential and commercial projects has escalated the need to develop and increase understanding of mass timber products both from a strength and serviceability perspective. For cross-laminated timber (CLT) there is a significant lack of research on the creep characteristics also known as long-term deflection behavior. Creep is particularly important for products such as CLT that are used for floors with longer spans. Full-scale creep testing was conducted using 5-ply CLT panels over the course of 6 months in a controlled environment under dry service condition. Testing resulted in average final deflections 1.73 times …


The Potential Of Iron Electrodes In Electrochemical Cells For The Stabilization Of Synthetic Urine, Skyler Voisin Aug 2023

The Potential Of Iron Electrodes In Electrochemical Cells For The Stabilization Of Synthetic Urine, Skyler Voisin

All Theses

Source separation and urine treatment present the opportunity to significantly reduce influent concentrations of nitrogen and phosphorus in wastewater treatment plants and to capture those minerals for reuse. This study aims to use electrochemical cells with a sacrificial iron electrode to produce hydrogen peroxide in situ for the stabilization of urea while dissolving ferrous iron ions to promote the precipitation of phosphate into compounds such as vivianite (Fe3 (PO4)2 ∙ 8 H2O), a precipitate with potential uses in agriculture and manufacturing. Synthetic urine samples were treated as anolyte, then were given time to form …


The Extent Of Drone Education Being Taught In Asc Schools To 4-Year Construction Students, Cheran Teja Dumpati Aug 2023

The Extent Of Drone Education Being Taught In Asc Schools To 4-Year Construction Students, Cheran Teja Dumpati

All Theses

The technology of Unmanned Aircraft Systems (UAS) is growing rapidly in many fields and has become one of the skills in demand in the industry. Universities are one of the primary sources of teaching drone technology with a career-oriented approach. The goal of this study is to investigate the content of the drone curriculum being taught in Associated Schools of Construction (ASC) schools. This includes the topics covered, practical training offered, and the key deliverables taught. This information serves as a foundation for the schools that are looking forward to start drone courses in their department. The research found that …


Explainable Physics-Informed Deep Learning For Rainfall-Runoff Modeling And Uncertainty Assessment Across The Continental United States, Sadegh Sadeghi Tabas May 2023

Explainable Physics-Informed Deep Learning For Rainfall-Runoff Modeling And Uncertainty Assessment Across The Continental United States, Sadegh Sadeghi Tabas

All Dissertations

Hydrologic models provide a comprehensive tool to calibrate streamflow response to environmental variables. Various hydrologic modeling approaches, ranging from physically based to conceptual to entirely data-driven models, have been widely used for hydrologic simulation. During the recent years, however, Deep Learning (DL), a new generation of Machine Learning (ML), has transformed hydrologic simulation research to a new direction. DL methods have recently proposed for rainfall-runoff modeling that complement both distributed and conceptual hydrologic models, particularly in a catchment where data to support a process-based model is scared and limited.

This dissertation investigated the applicability of two advanced probabilistic physics-informed DL …


Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin May 2023

Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin

All Dissertations

Inverse problems involve extracting the internal structure of a physical system from noisy measurement data. In many fields, the Bayesian inference is used to address the ill-conditioned nature of the inverse problem by incorporating prior information through an initial distribution. In the nonparametric Bayesian framework, surrogate models such as Gaussian Processes or Deep Neural Networks are used as flexible and effective probabilistic modeling tools to overcome the high-dimensional curse and reduce computational costs. In practical systems and computer models, uncertainties can be addressed through parameter calibration, sensitivity analysis, and uncertainty quantification, leading to improved reliability and robustness of decision and …


Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris May 2023

Impacts Of Preferential Flow On Tc-99and Np-237 Vadose Transport In Soils At The Savannah River Site, Josh Parris

All Theses

Since the 1950s, the United States has produced approximately 90,000 metric tons of spent nuclear fuel (SNF) (Office of Nuclear Energy, 2022); however, no long-term storage solutions are available. Technecium-99 and neptunium-237, two fission products found in SNF, readily form highly mobile species in oxidizing conditions (Hu, 2008; Bondietti, 1979) and have respective half-lives of 2.13 x 105 and 2.14 x106 years (Hu, 2010). Considering these characteristics, 99Tc and 237Np are two risk-driving isotopes found in SNF storage. The process of macropore-facilitated preferential flow, transport through cracks within a soil matrix, has been recognized to increase …