Geant4 Simulation For Radioactive Particle Tracking (Rpt) Technique, Ahmed A. Alghamdi, Thaar M. Aljuwaya, Abdullah S. Alomari, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In the past two decades, the radioactive particle tracking (RPT) measurement technique has been proven to visualize flow fields of most multiphase flow systems of industrial interest. The accuracy of RPT, and hence the data obtained, depend largely on the calibration process, which stands here as a basis for two subsequent processes: tracking and reconstruction. However, limitations in the RPT calibration process can be found in different experimental constrains and in assumptions made in the classical Monte Carlo approach used to simulate number of counts received by the detectors. Therefore, in this work, we applied a GEANT4-based Monte Carlo code …

Uranium 233: The Nuclear Superfuel No One Is Using, Maris Hanson

Seattle Journal of Technology, Environmental, & Innovation Law

Nuclear power offers more energy in less physical space than solar and wind and yields more energy per pound than fossil fuels. However different nuclear fuels yield different waste profiles and create different beneficial products. Uranium 233 (U233) resists use in nuclear weapons, yields beneficial daughter products, and produces dramatically less of the most problematic waste products than Uranium 235 (U235). U233 results from reactions with Thorium, a plentiful, ubiquitous element currently considered waste from rare earth mines. Additionally, U233 functions well in a liquid fuel reactor resulting in safer, more efficient reactors than current solid fuel U235 or Plutonium …

There From The Beginning: The Women Of Los Alamos National Laboratory Supporting National And International Nuclear Security, Olga Martin, Laura Mcclellan, Octavio Ramos, Heather Quinn

International Journal of Nuclear Security

From the beginning of the Manhattan Project in the early 1940s, the women of what would become Los Alamos National Laboratory (LANL) worked in technical positions alongside their male counterparts, played a key role as computers, and worked in administrative jobs as secretaries, phone operators, bookkeepers, and on behalf of the U.S. Army in the Women’s Army Corps.

Throughout the history of the Laboratory, women experts at LANL helped establish and lead important national and international security programs, with careers in science, technology, engineering, and mathematics. Over time, the women of Los Alamos have come together under various Employee Resource …

Analysis Of Non-Conventional Radiological Terrorism, James N. Padgett

Theses and Dissertations

Nuclear terrorism has been a risk since the dawn of the first atomic bomb. Though state sponsored nuclear weapons development is of concern for countries, non-state sponsored terrorism with radiological material can be of even greater concern. This stems from the fact that the material is under less stringent or no safeguards and can readily change hands between different terrorist groups or innocent civilians may accidently come into contact with the material.

Within this paper an analysis of previous accidents using orphan radiological sources, malicious use of orphan radiological sources, and how these sources could be used by terrorists is …

Effort And Prospective On Nuclear Security In Rok, Jung Soo Kim, Myung-Tak Jung, Kookheui Kwon, Youngwook Lee

International Journal of Nuclear Security

As of July 2013, the Republic of Korea (ROK) has been operating a total of 23 nuclear power reactors at four sites with five new reactors under construction. In addition, the country has planned to construct two more units at two candidate sites, but due to a change in the energy policy, only one candidate site has been constructed while the other was decommissioned. The ROK has also been exporting nuclear power plants to the United Arab Emirates (UAE) and building a research reactor in Jordan. These actions have made the nation’s nuclear industry by far the fastest growing industry …

Women In Nuclear Science & Technology In India: Challenges & Opportunities, Arpita Datta, Dr. Alpana Goel, Ashok Kumar Jain

International Journal of Nuclear Security

Women have been actively contributing toward frontline research and development of various advanced technologies in the nuclear domain and playing a crucial role in key positions. However, proportional representation of women in various decision-making positions at higher levels in politics, diplomacy, military affairs, science, and technology remains low, and most of these positions remain male-dominated. We see that women often find it difficult to achieve leadership roles for several reasons, but often from an implicit bias in society. The stereotypical image of women in society is still propagated very discreetly. In recent times, Indian women have made big strides in …

The Role Of Nuclear Forensics For Determining The Origin Of Nuclear Materials Out Of Regulatory Control And Nuclear Security, Lekhnath Ghimire, Edward Waller

International Journal of Nuclear Security

The international community recognizes the rise in theft and illicit trafficking of nuclear materials and radioactive sources—for malicious use and nuclear terrorism—as a serious threat. That is why a well-developed nuclear forensics capability is an integral part of a robust nuclear security program and a key element of nuclear security infrastructure. Both pre- and post-detonation nuclear forensics are vital for controlling theft and illicit trafficking of nuclear materials, as well as identifying and tracing their sources. Nuclear forensics analysis and interpretation processes for nuclear security is a systematic process that includes: (1) sample collection and categorization techniques and (2) detailed …

Developing Nuclear Security Capacity Of Indonesia’S Police And Security Officer: Lessons From Universitas Gadjah Mada’S Pilot Training, Susetyo Hario Putero Mr

International Journal of Nuclear Security

Due to an increase in global nuclear security issues, there need to be improvements in human resources and security measures. The Republic of Indonesia is an archipelago country, which makes surveilling for nuclear security threats complicated. Recent radioactive material smuggling incidents proved that Indonesian police and security officers’ knowledge in nuclear security has been challenged and must be improved. In response, Universitas Gadjah Mada’s Nuclear Engineering Program composed a three-day pilot training program for local police and UGM's security officers in 2018. The objective of the training was to improve their capabilities in dealing with nuclear security issues around where …

Nuclear Security Awareness Survey At A University, Marcia P. Robinson, Naomi German, Destiny B. White, Shraddha V. Rane, Jason Timothy Harris

International Journal of Nuclear Security

The concept of assessing safety culture in an organization emerged with its application at the nuclear power industry and has expanded since then. An assessment of nuclear security, on the contrary, is still under-developed, especially at non-nuclear facilities, such as academic institutions and medical facilities. To identify the level of the awareness and understanding of credible nuclear and radiological threats, response preparedness, security culture, and the integrity of nuclear security systems among non-radioactive material users at a university setting; a campus-wide survey was deployed. A total of 3,336 non-radioactive material users, including students, faculty, and staff participated in the survey. …

Particle Swarm Optimization For Critical Experiment Design, Cole Michael Kostelac

Masters Theses

“Critical experiments are used by nuclear data evaluators and criticality safety engineers to validate nuclear data and computational methods. Many of these experiments are designed to maximize the sensitivity to a certain nuclide-reaction pair in an energy range of interest. Traditionally, a parameter sweep is conducted over a set of experimental variables to find a configuration that is critical and maximally sensitive. As additional variables are added, the total number of configurations increases exponentially and quickly becomes prohibitively computationally expensive to calculate, especially using Monte Carlo methods.

This work presents the development of a particle swarm optimization algorithm to design …

Performance Degradation Based On Importance Change And Application In Dissimilar Redundancy Actuation System, Yadong Zhang, Chao Zhang, Shaoping Wang, Rentong Chen, Mileta M. Tomovic

Engineering Technology Faculty Publications

The importance measure is a crucial method to identify and evaluate the system weak link. It is widely used in the optimization design and maintenance decision of aviation, aerospace, nuclear energy and other systems. The dissimilar redundancy actuation system (DRAS) is a key aircraft control subsystem which performs aircraft attitude and flight trajectory control. Its performance and reliability directly affect the aircraft flight quality and flight safety. This paper considers the influence of the Birnbaum importance measure (BIM) and integrated importance measure (IIM) on the reliability changes of key components in DRAS. The differences of physical fault characteristics of different …

Helium-Air Mixing In Simulated Reactor Cavities Of Very High Temperature Reactors, Abdullah Abubakar

Dissertations and Theses

Abstract

Very High Temperature Reactors (VHTRs) and High Temperature Gas Reactors (HTGRs) are Generation IV gas reactors that promise to deliver high temperature process heat and efficient electricity for both industrial and commercial purposes. They have a high level of inherent passive safety making them a viable alternative to traditional water-cooled reactors. These helium gas-cooled reactors use graphite containing U-235 TRISO fuel particles in their core, as a moderator to slow down neutrons for fission chain reactions and for general core support. In the event of a primary circuit pipe break, the coolant gas escapes into the surrounding reactor cavity …

การกำจัดสีรีแอคทีฟในน้ำทิ้งจากอุตสาหกรรมสิ่งทอด้วยเครื่องเร่งอนุภาคอิเล็กตรอนพลังงานสูง, พัศราภรณ์ สุวรรณวโรดม

Chulalongkorn University Theses and Dissertations (Chula ETD)

ลำอิเล็กตรอนพลังงานสูงสามารถใช้บำบัดน้ำเสียทั้งในเชิงชีวภาพ (กำจัดเชื้อจุลินทรีย์ต่างๆ) และในเชิงเคมี (ย่อยสลายโมเลกุลขนาดใหญ่และซับซ้อนให้เล็กลง) ในเวลาเดียวกันได้ งานวิจัยนี้จึงนำเทคโนโลยีลำอิเล็กตรอนพลังงานสูงมาใช้ในการกำจัดสีย้อมรีแอคทีฟในน้ำทิ้งจากอุตสาหกรรมสิ่งทอ เพราะเป็นสีที่นิยมนํามาย้อมผ้า มีความคงตัวในสิ่งแวดล้อมสูง ทนทานต่อการซักล้าง และยากต่อการกำจัด ในการศึกษานี้ได้สังเคราะห์น้ำผสมกับสีรีแอคทีฟจำนวน 6 สี ได้แก่ สีแดง สีเหลือง สีน้ำเงิน สีชมพู สีฟ้า และสีดำ พร้อมกับเก็บตัวอย่างน้ำทิ้งจริงจากโรงงานย้อมผ้าในอำเภอสามพราน จังหวัดนครปฐม 1 ตัวอย่าง นำมาฉายลำอิเล็กตรอนพลังงานสูง 10 MeV ที่สถาบันเทคโนโลยีนิวเคลียร์แห่งชาติ (องค์การมหาชน) ที่ปริมาณรังสีต่างๆ กัน ผลการวิจัยพบว่าความเข้มสี, pH, COD, BOD5 และ TDS ลดลงตามปริมาณรังสีที่เพิ่มขึ้น และปริมาณรังสี 10 kGy สามารถกำจัดสีในน้ำที่สังเคราะห์ได้ ~92% ส่วนน้ำทิ้งจริงจากโรงงานย้อมผ้าต้องใช้ปริมาณรังสีสูงขึ้นในช่วง 50 kGy จึงจะสามารถกำจัดสีได้ ~80% ผลลัพธ์เหล่านี้แสดงถึงศักยภาพของการใช้เทคโนโลยีลำอิเล็กตรอนพลังงานสูงในการกำจัดสีย้อมรีแอคทีฟ ซึ่งเป็นเทคโนโลยีที่เป็นมิตรกับสิ่งแวดล้อมมากเพราะไม่ต้องใช้สารเคมีใดๆ ในการบำบัด จึงไม่มีสารเคมีตกค้างออกสู่สิ่งแวดล้อม เป็นการคืนสภาพความสะอาดและความปลอดภัยให้แก่น้ำที่จะปล่อยออกสู่งสิ่งแวดล้อม ซึ่งจะเป็นประโยชน์ต่อประชาชนอย่างยั่งยืน

Modeling Pa-233 Generation In Thorium-Fueled Reactors For Safeguards, Victoria Davis

Theses and Dissertations

Thorium has been researched for many decades as a possible alternative to uranium nuclear fuel. Thorium can be implemented in many different reactor designs including pressurized water reactors (PWRs), pressurized heavy water reactors (PHWRs), and molten salt reactors (MSRs). Its abundance in the earth, decreased long-lived transuranic waste, and claims that there are fewer proliferation concerns contribute to the attractiveness of using thorium as alternative nuclear fuel. However, possible proliferation pathways have been noted and must be investigated, particularly the potential diversion of ²³³Pa which can then decay to ²³³U – special fissionable material that should be under …

Molten Salt Technologies For Advanced Nuclear Fuel Cycles And Molten Salt Reactors, Dimitris Killinger

Theses and Dissertations

This dissertation provides five topics—an assessment of different monitoring and analytical techniques often cited in the literature for molten salt systems and designs for nuclear engineering applications. First, we explored commonly used materials for quasi-reference electrodes in molten chloride salts. Second, the limitations of the electrochemical analysis known as cyclic voltammetry due to the concentration of uranium(III) present were being investigated. Third, we provided an experimental assessment on the development of a spectroelectrochemical cell for interrogating various spectroelectrochemical techniques, namely chronoabsorptometry and chronofluorometry, and their limitations due to the presence of uranium(III) ions. Fourth, a study on the corrosion resistance …

Feasibility Of A Critical Experiment Utilizing Uranium Dioxide-Beryllium Oxide With Neutron Spectrum Shifting Capabilities, Ashley Rachel Raster

Masters Theses

“The goal of this project is to determine the feasibility of utilizing Annular Core Research Reactor (ACRR) fuel in core design with Sandia Pulse Reactor Facility’s (SPRF) Seven Percent Critical Experiment (7uPCX) fuel rods as driver fuel for a critical experiment facility to support future critical and benchmark experiments for the International Criticality Safety Benchmark Evaluation Project (ICSBEP) handbook. This is part of the Critical Experiment Design (CED) process for future criticality experiments. These criticality experiment designs have the main goal of being performed in the same facility at different neutron energy ranges. To test the feasibility of this experiment …

Effects Of Vacancies And Electron Temperature On The Electron Phonon Coupling In Cubic Silicon Carbide And Their Connection To The Inelastic Thermal Spike, Salah Al-Smairat

Doctoral Dissertations

“The electron-phonon interaction is an important interaction in many solids as it influences transport phenomena and related quantities such as the electrical and thermal conductivities, especially in nuclear and space applications. The importance of the electron-phonon interaction in primary damage production in 3C-SiC is the subject of this research.

The electron-phonon coupling factor was calculated using a hybrid Density Functional Perturbation Theory - Classical Electron Gas model. The coupling factor was calculated as a function of electron temperature in pristine and defective 3C-SiC, and relaxed defective cells. The electron-phonon coupling is found to depend strongly on the electronic temperature and …

Using Computational Methods To Optimize High Heat Flux Component Thermal Performance In Magnetic Confinement Fusion Reactor Research, Monica Gehrig

Doctoral Dissertations

"Heat transfer enhancement by means of internally modified geometries in tubes and channels is an important mechanism to improve the survivability of components in extreme high-heat flux environments. Various features such as ribs and fins are studied using computational fluid dynamics in both uniform and one-sided heating in tubes and rectangular channels respectively to determine the most effective geometries across a variety of different flow and heating conditions. This work examines heat transfer enhancement and rib geometry optimization to support experimental research for nuclear fusion applications. The project begins by designing and analyzing test sections supporting a helium flow loop …

Sensitivity Of The Two-Fluid Model To Constitutive Correlations For Large Diameter Pipes, Alexander Lee Swearingen

Doctoral Dissertations

"Multiphase flows are a significant factor in nuclear reactor operations. In order to understand this behavior in reactor systems, system analysis codes are used to simulate reactor conditions. Due to the nature of the nuclear industry, simulations predicting the void development in the core are required to be highly accurate. This work evaluated the sensitivity of the void fraction and interfacial area concentration predictions to changes in correlations used to calculate three parameters that are used to complete the interfacial drag calculation. The three parameters evaluated were drift-flux, void fraction covariance, and interfacial area concentration. The change in drift-flux correlation …

Characterization Of Cermet Fuel For Nuclear Thermal Propulsion (Ntp), James Floyd Mudd

Masters Theses

“A manned flight to Mars is met with many technical challenges, not the least of which is the development of propulsion technology capable of moving a transit vehicle from Earth orbit to Mars orbit. NASA is investigating Nuclear Thermal Propulsion (NTP) as a way of reducing flight time and providing the option for a mid-mission abort. NTP, which uses a high temperature nuclear reactor to heat a propellant, requires advanced fuel materials capable of withstanding temperatures well in excess of 2000 K. Among the fuel options are ceramic metal (cermet) composites composed of refractory metals and Ultra-High Temperature Ceramics (UHTCs). …

Validation Of Athlet-Cd With Cora-28 Test, Murat Tuter

Masters Theses

“Following the incidents at Chernobyl and Fukushima, severe accidents at nuclear power plants (NPP) have become a global concern. These accidents generally occur because of a failure in the reactor cooling system (RCS) and result in the melting of the reactor core and fission product release. This event is mostly caused by a LOCA, loss of flow accident, station blackout or loss of heat sink. During a severe accident, generation of hydrogen as a result of steam-zircaloy fuel cladding is a significant safety concern. To better understand and prevent the hydrogen generation issue, safety related experiments and safety related codes …

An Examination Between Laryngeal Physiology And Parkinson’S Disease: Severity And Treatment, Jillian Pelikan

University Honors Program

The purpose of this in-depth literature review is to examine the relationship between laryngeal physiology and Parkinson’s disease in terms of the severity and possible treatment. This research aims to determine the distinct characteristics of Parkinsonian speech and possible causes of these speech deficits. In addition, a specific type of Parkinson’s disease treatment, deep brain stimulation, was explored to determine effectiveness on laryngeal physiological deficits found in Parkinson’s disease patients. Through synthesizing peer reviewed journals and various studies, data was examined in order to take an in-depth look at the unique relationship between laryngeal physiology and Parkinson’s disease. Findings indicated …

Social Inflation: Rising Tides In The Insurance Markets, Noah E. Heim

University Honors Program

Social inflation, despite its relative recency, has been a strong concern for some of the largest insurance carriers in the world. With claims costs increasing across broad markets, especially in casualty markets, insurers are racing to find the reason why. Increased claims costs can result in a number of negative effects on both insurance carriers as well as insurances buyers. Social inflation seems to be a key driver of these increased costs. Doing a deep dive into the validity of this claim and studying some potential causes as well as markets in which social inflation is occurring has led to …

A New Dead-Time Determination Method For Gamma-Ray Detectors Using Attenuation Law, T. Akyurek

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

This study presents a new dead-time measurement method using the gamma attenuation law and generalized dead-time models for nuclear gamma-ray detectors. The dead-time of the NaI(Tl) detection system was obtained to validate the new dead-time determination method using very thin lead and polyethylene absorbers. Non-paralyzing dead-time was found to be 8.39 μs, and paralyzing dead-time was found to be 8.35 μs using lead absorber for NaI(Tl) scintillator detection system. These dead-time values are consistent with the previously reported dead-time values for scintillator detection systems. The gamma build-up factor's contribution to the dead-time was neglected because a very thin material was …

A Comparative Study Of Machine Learning Methods For Automated Identification Of Radioisotopes Using Nai Gamma-Ray Spectra, S. M. Galib, P. K. Bhowmik, A. V. Avachat, H. K. Lee

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

This article presents a study on the state-of-the-art methods for automated radioactive material detection and identification, using gamma-ray spectra and modern machine learning methods. The recent developments inspired this in deep learning algorithms, and the proposed method provided better performance than the current state-of-the-art models. Machine learning models such as: fully connected, recurrent, convolutional, and gradient boosted decision trees, are applied under a wide variety of testing conditions, and their advantage and disadvantage are discussed. Furthermore, a hybrid model is developed by combining the fully connected and convolutional neural network, which shows the best performance among the different machine learning …

Monte Carlo Perturbation Analysis Of Dimension And Density Variations Of The Annular Core Research Reactor Model Fuel, Karissa Currie

Nuclear Engineering ETDs

This thesis assesses sources of uncertainty in the neutron energy spectrum of the Annular Core Research Reactor (ACRR) Monte Carlo N-Particle Transport Code (MCNP) model. Uncertainty evaluations have been performed on the ACRR core but were computationally intensive and could not isolate the uncertainties associated with discrete sources. Monte Carlo Perturbation Theory (MCPT) is used in MCNP to calculate 640-group neutron energy fluences and their associated uncertainties [1]. To understand the uncertainties associated with only the UO₂-BeO fuel, perturbations in densities and dimensions were evaluated. A 640 by 640 covariance and correlation matrices were produced and compared to …

Athena: A Unique Radiation Environment Platform At The National Ignition Facility, Nicholas J. Quartemont, George Peterson, Colton Moran, Adib J. Samin, Buguo Wang, Charles Yeamans, Brandon Woodworth, Darren Holland, James C. Petrosky, James E. Bevins

Faculty Publications

This paper describes the ATHENA platform, an energy tuning assembly, which was developed to spectrally shape the National Ignition Facility (NIF) deuterium–tritium fusion neutron source to a thermonuclear (fusion) plus prompt fission neutron spectrum with a capability to act as a short-pulse neutron source. This unique, otherwise inaccessible radiation environment complements existing experimental facilities and capabilities. The flexible ATHENA irradiation positions were modeled using an ensemble of Monte Carlo simulations with stochastic sampling of the nuclear cross-sections to characterize the radiation environments and uncertainty for the platform. Validation of the internal neutron spectrum produced from fielding ATHENA at NIF occurred …

Regularized Heuristic Method For Activation Monitor Neutron Spectrum Unfolding, Nicholas J. Quartemont, James E. Bevins

Faculty Publications

his paper describes an activation foil measurement based neutron flux unfolding method utilizing a heuristic optimization approach. A regularization parameter based on the differential neutron flux was introduced into the optimization cost function to remove large nonphysical oscillations in the unfolded neutron energy spectrum. The procedure was completed for two example case studies ranging from thermal energies up to 20 MeV demonstrating recovery of neutron flux energy information on radiation environments where a model was partially missing or there was a discrepancy in a reaction channel. The unfolded results provided a distribution of unfolded spectra that conformed to the activation …

Space And Defense – Volume Twelve – Number Two – Summer 2021, Space And Defense Journal

Space and Defense

No abstract provided.

Thin Safety Margin: The Sefor Super-Prompt-Critical Transient Experiments, Ozark Mountains, Arkansas 1970–1971, Jerry Havens, Collis Geren

Arkansas Scholarly Editions

Thin Safety Margin charts the history of SEFOR, a twenty-megawatt reactor that operated for three years in the rural Ozark Mountains of Arkansas as part of an internationally sponsored program designed to demonstrate the Doppler effect in plutonium-oxide-fueled fast reactors. Authors Jerry Havens and Collis Geren draw upon this history to assess the accidental explosion risk inherent in using fast reactors to reduce the energy industry’s carbon dioxide emissions.

If a sufficiently powerful fast-neutron explosion were to cause the containment of a reactor such as SEFOR’s to fail, the reactor’s radiotoxic plutonium fuel could vaporize and escape into the surrounding …