2008 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site, Nye County, Nevada: Review of the Performance Assessments and Composite Analyses (open access)

2008 Annual Summary Report for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site, Nye County, Nevada: Review of the Performance Assessments and Composite Analyses

The Maintenance Plan for the Performance Assessments and Composite Analyses for the Area 3 and Area 5 Radioactive Waste Management Sites at the Nevada Test Site requires an annual review to assess the adequacy of the Performance Assessments (PAs) and Composite Analyses (CAs) for each of the facilities, with the results submitted annually to U.S. Department of Energy (DOE) Headquarters. The Disposal Authorization Statements for the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) also require that such reviews be made and that secondary or minor unresolved issues be tracked and addressed as part of the maintenance plan. The U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) performed an annual review in fiscal year (FY) 2008 by evaluating operational factors and research results that impact the continuing validity of the PAs and CAs. This annual summary report presents data and conclusions from the FY 2008 review, and determines the adequacy of the PAs and CAs. Operational factors (e.g., waste forms and containers, facility design, and waste receipts), closure plans, monitoring results, and research and development (R&D) activities were reviewed to determine the adequacy of the PAs. Likewise, the environmental restoration activities at the Nevada …
Date: March 30, 2009
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Bioremediation of Petroleum Hydrocarbon Contaminated Sites (open access)

Bioremediation of Petroleum Hydrocarbon Contaminated Sites

Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for …
Date: March 30, 2009
Creator: Fallgren, Paul
Object Type: Report
System: The UNT Digital Library
Electrical Resistivity and Seismic Surveys at the Nevada Test Site, Nevada, April 2007 (open access)

Electrical Resistivity and Seismic Surveys at the Nevada Test Site, Nevada, April 2007

In April 2007, the USGS collected direct-current (DC) electrical resistivity data and shear- (S) and compressional- (P) wave seismic data to provide new detail of previously mapped, overlapping fault splays at two administrative areas in the Nevada Test Site (NTS). In NTS Area 7, we collected two-dimensional DC resistivity data along a transect crossing the Yucca Fault parallel to, and between, two transects along which resistivity data were collected in a previous study in 2006. In addition, we collected three-dimensional DC resistivity data in a grid that overlies part of the 2007 transect. The DC resistivity data show that the fault has a footwall that is more conductive than the hanging wall and an along-strike progression of the fault in a location where overlapping splays are present. Co-located with the northernmost of the two 2006 DC resistivity transects, we acquired S- and P-wave seismic data for both reflection and refraction processing. The S-wave data are corrupted by large amounts of converted (P-wave) energy likely due to the abundance of fractured caliche in the shallow subsurface. The P-wave data show minimal reflected energy, but they show clear refracted first arrivals. We have inverted these first arrival times to determine P-wave seismic …
Date: March 30, 2009
Creator: Haines, Seth S.; Burton, Bethany L.; Sweetkind, Donald S. & Asch, Theodore H.
Object Type: Report
System: The UNT Digital Library
Energy Security and Restoration Exercise Program/Best Practices and Information Sharing (open access)

Energy Security and Restoration Exercise Program/Best Practices and Information Sharing

The first year of this cooperative agreement focused on the following elements: curriculum development and presentation, curriculum maintenance, enhancements, and effectiveness, and smart card initiative. During the second year of this grant, with redirection from DOE, the IUOE modified its mission statement under the cooperative agreement. It states: 'The mission of the IUOE is to provide expertise to provide best practices, information sharing, and develop scenarios and conduct exercises ranging in size and complexity from table top to national level to prepare all stakeholders to protect and restore energy infrastructure should an event, terrorist or natural, occur'. The Program developed a number of products under this Cooperative Agreement. These products include: FOSTER (Facility Operations Safety Training Event Response) Curriculum and Training Models, Alternative Energy Supply - Generators Training Module, Liquefied Natural Gas Training Module, Education Program - Distributed Generations, Compendium of Resources and References, Energy Security and Restoration Training Manual, Manual of Situations and Scenarios Developed for Emergency Exercises, Manual of Best Practices/Lessons Learned for Energy Load Management, Training Plan, Strategic Information and Exercise Plan, National Certification Plan Report, and a Smart Card Project Report.
Date: March 30, 2009
Creator: McCabe, Barbara & Kovach, John
Object Type: Report
System: The UNT Digital Library
FINAL REPORT WIND POWER WARM SPRINGS RESERVATION TRIBAL LANDS DOE GRANT NUMBER DE-FG36-07GO17077 SUBMITTED BY WARM SPRINGS POWER & WATER ENTERPRISES A CORPORATE ENTITY OF THE CONFEDERATED TRIBES OF WARM SPRINGS WARM SPRINGS, OREGON (open access)

FINAL REPORT WIND POWER WARM SPRINGS RESERVATION TRIBAL LANDS DOE GRANT NUMBER DE-FG36-07GO17077 SUBMITTED BY WARM SPRINGS POWER & WATER ENTERPRISES A CORPORATE ENTITY OF THE CONFEDERATED TRIBES OF WARM SPRINGS WARM SPRINGS, OREGON

Wind Generation Feasibility Warm Springs Power and Water Enterprises (WSPWE) is a corporate entity owned by the Confederated Tribes of the Warm Springs Reservation, located in central Oregon. The organization is responsible for managing electrical power generation facilities on tribal lands and, as part of its charter, has the responsibility to evaluate and develop renewable energy resources for the Confederated Tribes of Warm Springs. WSPWE recently completed a multi-year-year wind resource assessment of tribal lands, beginning with the installation of wind monitoring towers on the Mutton Mountains site in 2003, and collection of on-site wind data is ongoing. The study identified the Mutton Mountain site on the northeastern edge of the reservation as a site with sufficient wind resources to support a commercial power project estimated to generate over 226,000 MWh per year. Initial estimates indicate that the first phase of the project would be approximately 79.5 MW of installed capacity. This Phase 2 study expands and builds on the previously conducted Phase 1 Wind Resource Assessment, dated June 30, 2007. In order to fully assess the economic benefits that may accrue to the Tribes through wind energy development at Mutton Mountain, a planning-level opinion of probable cost was performed …
Date: March 30, 2009
Creator: Manion, Jim; Lofting, Michael; Sando, Wil; Leslie, Emily & Goff, Randy
Object Type: Report
System: The UNT Digital Library
Geochemical Study of Grab Samples Collected From BX Tank Farm Borehole C5989 (open access)

Geochemical Study of Grab Samples Collected From BX Tank Farm Borehole C5989

This is an analytical data report for sediments received from BX Tank Farm.
Date: March 30, 2009
Creator: Lindberg, Michael J.
Object Type: Report
System: The UNT Digital Library
Health Physics Enrollments and Degrees Survey, 2008 Data (open access)

Health Physics Enrollments and Degrees Survey, 2008 Data

The survey includes degrees granted between September 1, 2007 and August 31, 2008. Enrollment information refers to the fall term 2008. Twenty-six academic programs were included in the survey universe, and all 26 programs provided data.
Date: March 30, 2009
Creator: Analysis and Evaluation, Science Education Programs
Object Type: Report
System: The UNT Digital Library
India Energy Outlook: End Use Demand in India to 2020 (open access)

India Energy Outlook: End Use Demand in India to 2020

Integrated economic models have been used to project both baseline and mitigation greenhouse gas emissions scenarios at the country and the global level. Results of these scenarios are typically presented at the sectoral level such as industry, transport, and buildings without further disaggregation. Recently, a keen interest has emerged on constructing bottom up scenarios where technical energy saving potentials can be displayed in detail (IEA, 2006b; IPCC, 2007; McKinsey, 2007). Analysts interested in particular technologies and policies, require detailed information to understand specific mitigation options in relation to business-as-usual trends. However, the limit of information available for developing countries often poses a problem. In this report, we have focus on analyzing energy use in India in greater detail. Results shown for the residential and transport sectors are taken from a previous report (de la Rue du Can, 2008). A complete picture of energy use with disaggregated levels is drawn to understand how energy is used in India and to offer the possibility to put in perspective the different sources of end use energy consumption. For each sector, drivers of energy and technology are indentified. Trends are then analyzed and used to project future growth. Results of this report provide valuable …
Date: March 30, 2009
Creator: de la Rue du Can, Stephane; McNeil, Michael & Sathaye, Jayant
Object Type: Report
System: The UNT Digital Library
Ion Uptake Determination of Dendrochronologically-Dated Trees Using Neutron Activation Analysis (open access)

Ion Uptake Determination of Dendrochronologically-Dated Trees Using Neutron Activation Analysis

Uptake of metal ions by plan roots is a function of the type and concentration of metal in the soil, the nutrient biochemistry of the plant, and the immediate environment of the root. Uptake of gold (Au) is known to be sensitive to soil pH for many species. Soil acidification due to acid precipitation following volcanic eruptions can dramatically increase Au uptake by trees. Identification of high Au content in tree rings in dendrochronologically-dated, overlapping sequences of trees allows the identification of temporally-conscribed, volcanically-influenced periods of environmental change. Ion uptake, specifically determination of trace amounts of gold, was performed for dendrochronologically-dated tree samples utilizing Neutron Activation Analysis (NAA) technique. The concentration of gold was correlated with known enviironmental changes, e.g. volcanic activities, during historic periods.
Date: March 30, 2009
Creator: Unlu, Kenan; Kuniholm, P. I.; Schwarz, D. K. H.; Cetiner, N. O. & Chiment, J. J.
Object Type: Report
System: The UNT Digital Library
Looking for Darwin's footprints in the microbial world (open access)

Looking for Darwin's footprints in the microbial world

As we observe the 200th anniversary of Charles Darwin's birthday, microbiologists interested in the application of Darwin's ideas to the microscopic world have a lot to celebrate: an emerging picture of the (mostly microbial) Tree of Life at ever-increasing resolution, an understanding of horizontal gene transfer as a driving force in the evolution of microbes, and thousands of complete genome sequences to help formulate and refine our theories. At the same time, quantitative models of the microevolutionary processes shaping microbial populations remain just out of reach, a point that is perhaps most dramatically illustrated by the lack of consensus on how (or even whether) to define bacterial species. We summarize progress and prospects in bacterial population genetics, with an emphasis on detecting the footprint of positive Darwinian selection in microbial genomes.
Date: March 30, 2009
Creator: Shapiro, B. Jesse; David, Lawrence A.; Friedman, Jonathan & Alm, Eric J.
Object Type: Article
System: The UNT Digital Library
Low Temperature Combustion with Thermo-Chemical Recuperation to Maximize In-Use Engine Efficiency (open access)

Low Temperature Combustion with Thermo-Chemical Recuperation to Maximize In-Use Engine Efficiency

The key to overcome Low Temperature Combustion (LTC) load range limitations in reciprocating engines is based on proper control over the thermo-chemical properties of the in-cylinder charge. The studied alternative to achieve the required control of LTC is the use of two separate fuel streams to regulate timing and heat release at specific operational points, where the secondary fuel is a reformed product of the primary fuel in the tank. It is proposed in this report that the secondary fuel can be produced using exhaust heat and Thermo-Chemical Recuperation (TCR). TCR for reciprocating engines is a system that employs high efficiency recovery of sensible heat from engine exhaust gas and uses this energy to transform fuel composition. The recuperated sensible heat is returned to the engine as chemical energy. Chemical conversions are accomplished through catalytic and endothermic reactions in a specially designed reforming reactor. An equilibrium model developed by Gas Technology Institute (GTI) for heptane steam reforming was applied to estimate reformed fuel composition at different reforming temperatures. Laboratory results, at a steam/heptane mole ratio less than 2:1, confirm that low temperature reforming reactions, in the range of 550 K to 650 K, can produce 10-30% hydrogen (by volume, wet) …
Date: March 30, 2009
Creator: Clark, Nigel N.; Posada, Francisco; Bedick, Clinton; Pratapas, John; Kozlov, Aleksandr; Linck, Martin et al.
Object Type: Report
System: The UNT Digital Library
Melt spreading code assessment, modifications, and application to the EPR core catcher design. (open access)

Melt spreading code assessment, modifications, and application to the EPR core catcher design.

The Evolutionary Power Reactor (EPR) is under consideration by various utilities in the United States to provide base load electrical production, and as a result the design is undergoing a certification review by the U.S. Nuclear Regulatory Commission (NRC). The severe accident design philosophy for this reactor is based upon the fact that the projected power rating results in a narrow margin for in-vessel melt retention by external cooling of the reactor vessel. As a result, the design addresses ex-vessel core melt stabilization using a mitigation strategy that includes: (1) an external core melt retention system to temporarily hold core melt released from the vessel; (2) a layer of 'sacrificial' material that is admixed with the melt while in the core melt retention system; (3) a melt plug in the lower part of the retention system that, when failed, provides a pathway for the mixture to spread to a large core spreading chamber; and finally, (4) cooling and stabilization of the spread melt by controlled top and bottom flooding. The overall concept is illustrated in Figure 1.1. The melt spreading process relies heavily on inertial flow of a low-viscosity admixed melt to a segmented spreading chamber, and assumes that the …
Date: March 30, 2009
Creator: Farmer, M. T.
Object Type: Report
System: The UNT Digital Library
Next-to-Leading Order Calculation of the Single Transverse Spin Asymmetry in the Drell-Yan Process (open access)

Next-to-Leading Order Calculation of the Single Transverse Spin Asymmetry in the Drell-Yan Process

We calculate the next-to-leading order perturbative QCD corrections to the transverse momentum weighted single transverse spin asymmetry in Drell-Yan lepton pair production in hadronic collisions. We identify the splitting function relevant for the scale evolution of the twist-three quark-gluon correlation function. We comment on the consequences of our results for phenomenology.
Date: March 30, 2009
Creator: Vogelsang, Werner & Yuan, Feng
Object Type: Article
System: The UNT Digital Library
Nuclear Engineering Enrollments and Degrees Survey, 2008 Data (open access)

Nuclear Engineering Enrollments and Degrees Survey, 2008 Data

The survey includes degrees granted between September 1, 2007, and August 31, 2008, and fall 2008 enrollments. Thirty-one academic programs reported having nuclear engineering programs during 2008, and data was provided by all thirty-one programs.
Date: March 30, 2009
Creator: Analysis and Evaluation, Science Education Programs
Object Type: Report
System: The UNT Digital Library
Observations on Faults and Associated Permeability Structures in Hydrogeologic Units at the Nevada Test Site (open access)

Observations on Faults and Associated Permeability Structures in Hydrogeologic Units at the Nevada Test Site

Observational data on Nevada Test Site (NTS) faults were gathered from a variety of sources, including surface and tunnel exposures, core samples, geophysical logs, and down-hole cameras. These data show that NTS fault characteristics and fault zone permeability structures are similar to those of faults studied in other regions. Faults at the NTS form complex and heterogeneous fault zones with flow properties that vary in both space and time. Flow property variability within fault zones can be broken down into four major components that allow for the development of a simplified, first approximation model of NTS fault zones. This conceptual model can be used as a general guide during development and evaluation of groundwater flow and contaminate transport models at the NTS.
Date: March 30, 2009
Creator: Prothro, Lance B.; Drellack, Sigmund L.; Haugstad, Dawn N.; Huckins-Gang, Heather E. & Townsend, Margaret J.
Object Type: Report
System: The UNT Digital Library
Pyramidal and Chiral Groupings of Gold Nanocrystals Assembled Using DNA Scaffolds (open access)

Pyramidal and Chiral Groupings of Gold Nanocrystals Assembled Using DNA Scaffolds

Nanostructures constructed from metal and semiconductor nanocrystals conjugated to, and organized by DNA are an emerging class of material with collective optical properties. We created discrete pyramids of DNA with gold nanocrystals at the tips. By taking small angle X-ray scattering (SAXS) measurments from solutions of these pyramids we confirmed that this pyramidal geometry creates structures which are more rigid in solution than linear DNA. We then took advantage of the tetrahedral symmetry to demonstrate construction of chiral nanostructures.
Date: March 30, 2009
Creator: Mastroianni, Alexander; Claridge, Shelley & Alivisatos, A. Paul
Object Type: Article
System: The UNT Digital Library
Quarkyonic Matter and the Revised Phase Diagram of QCD (open access)

Quarkyonic Matter and the Revised Phase Diagram of QCD

At high baryon number density, it has been proposed that a new phase of QCD matter controlsthe physics. This matter is confining but can have densities much larger than 3QCD. Its existenceis argued from large Nc approximations, and model computations. It is approximately chirallysymmetric.
Date: March 30, 2009
Creator: McLerran, L.
Object Type: Article
System: The UNT Digital Library
Real-Time Gene Expression Profiling of Live Shewanella Oneidensis Cells (open access)

Real-Time Gene Expression Profiling of Live Shewanella Oneidensis Cells

The overall objective of this proposal is to make real-time observations of gene expression in live Shewanella oneidensis cells with high sensitivity and high throughput. Gene expression, a central process to all life, is stochastic because most genes often exist in one or two copies per cell. Although the central dogma of molecular biology has been proven beyond doubt, due to insufficient sensitivity, stochastic protein production has not been visualized in real time in an individual cell at the single-molecule level. We report the first direct observation of single protein molecules as they are generated, one at a time in a single live E. coli cell, yielding quantitative information about gene expression [Science 2006; 311: 1600-1603]. We demonstrated a general strategy for live-cell single-molecule measurements: detection by localization. It is difficult to detect single fluorescence protein molecules inside cytoplasm - their fluorescence is spread by fast diffusion to the entire cell and overwhelmed by the strong autofluorescence. We achieved single-molecule sensitivity by immobilizing the fluorescence protein on the cell membrane, where the diffusion is much slowed. We learned that under the repressed condition protein molecules are produced in bursts, with each burst originating from a stochastically-transcribed single messenger RNA molecule, …
Date: March 30, 2009
Creator: Xie, Xiaoliang Sunney
Object Type: Report
System: The UNT Digital Library
Solving large-scale sparse eigenvalue problems and linear systems of equations for accelerator modeling (open access)

Solving large-scale sparse eigenvalue problems and linear systems of equations for accelerator modeling

The solutions of sparse eigenvalue problems and linear systems constitute one of the key computational kernels in the discretization of partial differential equations for the modeling of linear accelerators. The computational challenges faced by existing techniques for solving those sparse eigenvalue problems and linear systems call for continuing research to improve on the algorithms so that ever increasing problem size as required by the physics application can be tackled. Under the support of this award, the filter algorithm for solving large sparse eigenvalue problems was developed at Stanford to address the computational difficulties in the previous methods with the goal to enable accelerator simulations on then the world largest unclassified supercomputer at NERSC for this class of problems. Specifically, a new method, the Hemitian skew-Hemitian splitting method, was proposed and researched as an improved method for solving linear systems with non-Hermitian positive definite and semidefinite matrices.
Date: March 30, 2009
Creator: Golub, Gene & Ko, Kwok
Object Type: Report
System: The UNT Digital Library
Stress- and Chemistry-Mediated Permeability Enhancement/Degradation in Stimulated Critically-Stressed Fractures (open access)

Stress- and Chemistry-Mediated Permeability Enhancement/Degradation in Stimulated Critically-Stressed Fractures

This work has investigated the interactions between stress and chemistry in controlling the evolution of permeability in stimulated fractured reservoirs through an integrated program of experimentation and modeling. Flow-through experiments on natural and artificial fractures in Coso diorite have examined the evolution of permeability under paths of mean and deviatoric stresses, including the role of dissolution and precipitation. Models accommodating these behaviors have examined the importance of incorporating the complex couplings between stress and chemistry in examining the evolution of permeability in EGS reservoirs. This document reports the findings of experiment [1,2] and analysis [3,4], in four sequential chapters.
Date: March 30, 2009
Creator: Elsworth, Derek; Grader, Abraham S.; Marone, Chris; Halleck, Phillip; Rose, Peter; Faoro, Igor et al.
Object Type: Report
System: The UNT Digital Library
Subtask 7.1 - Strategic Studies (open access)

Subtask 7.1 - Strategic Studies

The Energy & Environmental Research Center (EERC) has recently completed 11 years of research through the Cooperative Agreement with the U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) focused on fossil energy technology development and demonstration. To support a significant number of the different activities being considered within all of our research contracts with NETL, a subtask (7.1 Strategic Studies) was created to focus on small research efforts that came up throughout the year which would support an existing EERC-NETL project or would help to develop a new concept for inclusion in future efforts. Typical efforts conducted under this task were usually between $15,000 and $60,000 in scope and had time lines of less than 6 months. A limited number of larger studies were also conducted, generally at the direct request of NETL. Over the life of this task, 46 projects were conducted. These efforts ranged from quick experiments to gain fundamental knowledge to support a current effort, to literature reviews, to a few larger engineering efforts.
Date: March 30, 2009
Creator: Erickson, Thomas
Object Type: Report
System: The UNT Digital Library
Water Quality Trends in the Entiat River Subbasin: Final 2008 Annual Report. (open access)

Water Quality Trends in the Entiat River Subbasin: Final 2008 Annual Report.

The ISEMP program monitors the status and trend of water quality elements that may affect restoration project effectiveness in the Entiat subbasin. As part of this effort, the PNW Research Station (PNW) measures, analyzes and interprets temporal trends in natural stream water pH, dissolved oxygen, specific conductivity and temperature. The Entiat River is currently on the Clean Water Act 303(d) list for pH exceedence, and there is insufficient information to determine the spatial and temporal extent or potential causes of this exceedence. In the spring 2008, PNW redeployed data-logging, multiparameter probes at four locations in the Entiat subbasin to measure water quality parameters, focusing on pH. This resumed previous data collection that was interrupted by river ice in early December 2007. Instruments were again removed from the river in early December 2008. This annual report covers the period from December 2007 through December 2008. The highest pH values occurred during the low-flow period from midsummer through the following midspring then dropped sharply during the annual snowmelt runoff period from late spring through early summer. Water temperature began rapidly increasing during the receding limb of the annual snowmelt hydrograph. Highest mean monthly temperatures occurred in July and August, while instantaneous maxima …
Date: March 30, 2009
Creator: Woodsmith, Richard & Bookter, Andy
Object Type: Report
System: The UNT Digital Library
EVermont Renewable Hydrogen Production and Transportation Fueling System (open access)

EVermont Renewable Hydrogen Production and Transportation Fueling System

A great deal of research funding is being devoted to the use of hydrogen for transportation fuel, particularly in the development of fuel cell vehicles. When this research bears fruit in the form of consumer-ready vehicles, will the fueling infrastructure be ready? Will the required fueling systems work in cold climates as well as they do in warm areas? Will we be sure that production of hydrogen as the energy carrier of choice for our transit system is the most energy efficient and environmentally friendly option? Will consumers understand this fuel and how to handle it? Those are questions addressed by the EVermont Wind to Wheels Hydrogen Project: Sustainable Transportation. The hydrogen fueling infrastructure consists of three primary subcomponents: a hydrogen generator (electrolyzer), a compression and storage system, and a dispenser. The generated fuel is then used to provide transportation as a motor fuel. EVermont Inc., started in 1993 by then governor Howard Dean, is a public-private partnership of entities interested in documenting and advancing the performance of advanced technology vehicles that are sustainable and less burdensome on the environment, especially in areas of cold climates, hilly terrain and with rural settlement patterns. EVermont has developed a demonstration wind powered …
Date: March 30, 2008
Creator: Wight, Harold T.; Dreier, Gregory & Borland, Ken
Object Type: Report
System: The UNT Digital Library
Fundamental Approach to TRIGA Steady-State Athermal-Hydraulic CHF Analysis. (open access)

Fundamental Approach to TRIGA Steady-State Athermal-Hydraulic CHF Analysis.

Methods are investigated for predicting the power at which critical heat flux (CHF) occurs in TRIGA reactors that rely on natural convection for primary flow. For a representative TRIGA reactor, two sets of functions are created. For the first set, the General Atomics STAT code and the more widely-used RELAP5-3D code are each employed to obtain reactor flow rate as a function of power. For the second set, the Bernath correlation, the 2006 Groeneveld table, the Hall and Mudawar outlet correlation, and each of the four PG-CHF correlations for rod bundles are used to predict the power at which CHF occurs as a function of channel flow rate. The two sets of functions are combined to yield predictions of the power at which CHF occurs in the reactor. A combination of the RELAP5-3D code and the 2006 Groeneveld table predicts 67% more CHF power than does a combination of the STAT code and the Bernath correlation. Replacing the 2006 Groeneveld table with the Bernath CHF correlation (while using the RELAP5-3D code flow solution) causes the increase to be 23% instead of 67%. Additional RELAP5-3D flow-versus-power solutions obtained from Reference 1 and presented in Appendix B for four specific TRIGA reactors …
Date: March 30, 2008
Creator: Feldman, E.
Object Type: Report
System: The UNT Digital Library