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You searched for +publisher:"Texas A&M University" +contributor:("Yates, Justin T"). Showing records 1 – 3 of 3 total matches.

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Texas A&M University

1. Martin, John Francis. Prototype Demonstration of Gamma Insensitive Centrifugally Tensioned Metastable Fluid Neutron / Alpha Detector.

Degree: 2015, Texas A&M University

Tensioned metastable fluid detectors are a novel detector concept with a wide array of potential uses. A particularly interesting application is as a real-time alpha and neutron detector that is also insensitive to gamma rays. This type of detector could have many uses for safeguards and nonproliferation including reprocessing facilities and border protection. For safeguards facilities, the detector could be used to perform online measurements of alpha-emitting nuclides such as uranium and plutonium in the reprocessing fluids. The online measurements could include dissolver tank fluids and products solution fluids where conventional detector use is infeasible. In this research, an initial characterization of one version of the tensioned metastable fluid detector (TMFD) was performed. A TMFD works by putting a fluid under negative pressure or tension. Once under tension, small amounts of energy can cause the tensioned molecules in the fluid to burst apart forming a visible bubble. The small amount of energy can come from nuclear particles such as alphas and neutrons. Another key concept of the TMFD is that the amount of energy needed to form a bubble is dependent on the negative pressure of the fluid. By varying the negative pressure, only particles of a desired energy or higher would form bubbles in the system allowing for a form of spectroscopy. The spectroscopy could be used, along with a volume measurement, to quantify the amount of uranium or plutonium in the reprocessing fluid. The initial characterization was performed using gamma, neutron, and alpha radiation. The gamma-ray tests were performed using an external 137Cs source next to the system. Several neutron tests were performed using an external 252Cf sourceincluding a test to verify compliance with the inverse square law and a test varying the pressure of the TMFD to test spectroscopy uses. Last, alpha-radiation tests were conducted using various amounts of depleted uranium dissolved in the working fluid of the detector. This study confirmed that the detector system is insensitive to low amounts of gamma-rays. It also confirmed that by varying the negative pressure in the detector, different energy neutrons could be detected. Last, the study confirmed that the detector could be used to detect alpha particles in real time but that additional work was needed on the design to ensure reliable results. The TMFD can be used to detect alpha particles and neutrons and is insensitive to gamma-rays. However, the current design of the system is a prototype and must be redesigned in order to be used in a reprocessing facility. Also, a lower negative pressure is needed for neutron detection compared to alpha detection. The pressure discrepancy would cause the detector to be unable to detect alpha particles in a large neutron radiation field making the detector unusable at the dissolver tank, but still usable for the reprocessing product lines. Advisors/Committee Members: Charlton, William S (advisor), Poston, John W (committee member), Yates, Justin T (committee member).

Subjects/Keywords: Nuclear Engineering; Nuclear Safeguards; Nuclear Nonproliferation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Martin, J. F. (2015). Prototype Demonstration of Gamma Insensitive Centrifugally Tensioned Metastable Fluid Neutron / Alpha Detector. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/155630

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Martin, John Francis. “Prototype Demonstration of Gamma Insensitive Centrifugally Tensioned Metastable Fluid Neutron / Alpha Detector.” 2015. Thesis, Texas A&M University. Accessed June 25, 2019. http://hdl.handle.net/1969.1/155630.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Martin, John Francis. “Prototype Demonstration of Gamma Insensitive Centrifugally Tensioned Metastable Fluid Neutron / Alpha Detector.” 2015. Web. 25 Jun 2019.

Vancouver:

Martin JF. Prototype Demonstration of Gamma Insensitive Centrifugally Tensioned Metastable Fluid Neutron / Alpha Detector. [Internet] [Thesis]. Texas A&M University; 2015. [cited 2019 Jun 25]. Available from: http://hdl.handle.net/1969.1/155630.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Martin JF. Prototype Demonstration of Gamma Insensitive Centrifugally Tensioned Metastable Fluid Neutron / Alpha Detector. [Thesis]. Texas A&M University; 2015. Available from: http://hdl.handle.net/1969.1/155630

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Texas A&M University

2. Gitau, Ernest Travis Ngure. Development and Evaluation of a Safeguards System Concept for a Pebble-Fueled High Temperature Gas-cooled Reactor.

Degree: 2012, Texas A&M University

Pebble-fueled high temperature gas-cooled reactor (HTGR) technology was first developed by the Federal Republic of Germany in the 1950s. More recently, the design has been embraced by the People's Republic of China and the Republic of South Africa. Unlike light water reactors that generate heat from fuel assemblies comprised of fuel rods, pebble-fueled HTGRs utilize thousands of 60-mm diameter fuel spheres (pebbles) comprised of thousands of TRISO particles. As this reactor type is deployed across the world, adequate methods for safeguarding the reactor must be developed. Current safeguards methods for the pebble-fueled HTGR focus on extensive, redundant containment and surveillance (C/S) measures or a combination of item-type and bulk-type material safeguards measures to deter and detect the diversion of fuel pebbles. The disadvantages to these approaches are the loss of continuity of knowledge (CoK) when C/S systems fail, or are compromised, and the introduction of material unaccounted for (MUF). Either vulnerability can be exploited by an adversary to divert fuel pebbles from the reactor system. It was determined that a solution to maintaining CoK is to develop a system to identify each fuel pebble that is inserted and removed from the reactor. Work was performed to develop and evaluate the use of inert microspheres placed in each fuel pebble, whose random placement could be used as a fingerprint to identify the fuel pebble. Ultrasound imaging of 1 mm zirconium oxide microspheres was identified as a possible imaging system and microsphere material for the new safeguards system concept. The system concept was evaluated, and it was found that a minimum of three microspheres are necessary to create enough random fingerprints for 10,000,000 pebbles. It was also found that, over the lifetime of the reactor, less than 0.01% of fuel pebbles can be expected to have randomly the same microsphere fingerprint. From an MCNP 5.1 model, it was determined that less than fifty microspheres in each pebble will have no impact on the reactivity or temperature coefficient of reactivity of the reactor system. Finally, using an ultrasound system it was found that ultrasound waves can penetrate thin layers of graphite to image the microsphere fingerprint. Advisors/Committee Members: Charlton, William S. (advisor), Tsvetkov, Pavel V. (committee member), Yates, Justin T. (committee member).

Subjects/Keywords: non-proliferation; PBMR; pebble bed; nuclear safeguards; nonproliferation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Gitau, E. T. N. (2012). Development and Evaluation of a Safeguards System Concept for a Pebble-Fueled High Temperature Gas-cooled Reactor. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9868

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Gitau, Ernest Travis Ngure. “Development and Evaluation of a Safeguards System Concept for a Pebble-Fueled High Temperature Gas-cooled Reactor.” 2012. Thesis, Texas A&M University. Accessed June 25, 2019. http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9868.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Gitau, Ernest Travis Ngure. “Development and Evaluation of a Safeguards System Concept for a Pebble-Fueled High Temperature Gas-cooled Reactor.” 2012. Web. 25 Jun 2019.

Vancouver:

Gitau ETN. Development and Evaluation of a Safeguards System Concept for a Pebble-Fueled High Temperature Gas-cooled Reactor. [Internet] [Thesis]. Texas A&M University; 2012. [cited 2019 Jun 25]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9868.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gitau ETN. Development and Evaluation of a Safeguards System Concept for a Pebble-Fueled High Temperature Gas-cooled Reactor. [Thesis]. Texas A&M University; 2012. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9868

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Texas A&M University

3. Na, Hyeong Suk. Large-Scale Evacuation Network Model for Transporting Evacuees with Multiple Priorities.

Degree: 2014, Texas A&M University

There are increasing numbers of natural disasters occurring worldwide, particularly in populated areas. Such events affect a large number of people causing injuries and fatalities. With ever increasing damage being caused by large-scale natural disasters, the need for appropriate evacuation strategies has grown dramatically. Providing rapid medical treatment is of utmost importance in such circumstances. The problem of transporting patients to medical facilities is a subject of research that has been studied to some extent. One of the challenges is to find a strategy that can maximize the number of survivors and minimize the total cost simultaneously under a given set of resources and geographic constraints. However, some existing mathematical programming methodologies cannot be applied effectively to such large-scale problems. In this thesis, two mathematical optimization models are proposed for abating the extensive damage and tragic impact by large-scale natural disasters. First of all, a mathematical optimization model called Triage-Assignment-Transportation (TAT) model is suggested in order to decide on the tactical routing assignment of several classes of evacuation vehicles between staging areas and shelters in the nearby area. The model takes into account the severity level of the evacuees, the evacuation vehicles? capacities, and available resources of each shelter. TAT is a mixed-integer linear programming (MILP) and minimum-cost flow problem. Comprehensive computational experiments are performed to examine the applicability and extensibility of the TAT model. Secondly, a MILP model is addressed to solve the large-scale evacuation network problem with multi-priorities evacuees, multiple vehicle types, and multiple candidate shelters. An exact solution approach based on modified Benders? decomposition is proposed for seeking relevant evacuation routes. A geographical methodology for a more realistic initial parameter setting is developed by employing spatial analysis techniques of a GIS. The objective is to minimize the total evacuation cost and to maximize the number of survivors simultaneously. In the first stage, the proposed model identifies the number and location of shelters and strategy to allocate evacuation vehicles. The subproblem in the second stage determines initial stock and distribution of medical resources. To validate the proposed model, the solutions are compared with solutions derived from two solution approaches, linear programming relaxation and branch-and-cut algorithm. Finally, results from comprehensive computational experiments are examined to determine applicability and extensibility of the proposed model. The two evacuation models for large-scale natural disasters can offer insight to decision makers about the number of staging areas, evacuation vehicles, and medical resources that are required to complete a large-scale evacuation based on the estimated number of evacuees. In addition, we believe that our proposed model can serve as the centerpiece for a disaster evacuation… Advisors/Committee Members: Banerjee, Amarnath P (advisor), Yates, Justin T (committee member), Quadrifoglio, Luca (committee member).

Subjects/Keywords: Large-scale optimization model; modified Benders' decomposition; natural disaster evacuation plan; geographic information system; mixed integer linear programming

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Na, H. S. (2014). Large-Scale Evacuation Network Model for Transporting Evacuees with Multiple Priorities. (Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152810

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Na, Hyeong Suk. “Large-Scale Evacuation Network Model for Transporting Evacuees with Multiple Priorities.” 2014. Thesis, Texas A&M University. Accessed June 25, 2019. http://hdl.handle.net/1969.1/152810.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Na, Hyeong Suk. “Large-Scale Evacuation Network Model for Transporting Evacuees with Multiple Priorities.” 2014. Web. 25 Jun 2019.

Vancouver:

Na HS. Large-Scale Evacuation Network Model for Transporting Evacuees with Multiple Priorities. [Internet] [Thesis]. Texas A&M University; 2014. [cited 2019 Jun 25]. Available from: http://hdl.handle.net/1969.1/152810.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Na HS. Large-Scale Evacuation Network Model for Transporting Evacuees with Multiple Priorities. [Thesis]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152810

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.