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Optimization of electron-cyclotron-resonance charge-breeder ions : Final CRADA Report. (open access)

Optimization of electron-cyclotron-resonance charge-breeder ions : Final CRADA Report.

Measurements of 1+ beam properties and associated performance of ECR Charge Breeder source determined by total efficiency measurement and charge state distributions from the ECR Charge Breeder. These results were communicated to Far-Tech personnel who used them to benchmark the newly developed programs that model ion capture and charge breeding in the ECR Charge Breeder Source. Providing the basic data described above and in the discussion below to Far-Tech allowed them to improve and refine their calculational tools for ECR ion sources. These new tools will be offered for sale to industry and will also provide important guidance to other research labs developing Charge Breeding ion sources for radioactive beam physics research.
Date: October 9, 2009
Creator: Pardo, R.; Physics & Far-Tech, Inc.
System: The UNT Digital Library
YALINA Analytical Benchmark Analyses Using the Deterministic ERANOS Code System. (open access)

YALINA Analytical Benchmark Analyses Using the Deterministic ERANOS Code System.

The growing stockpile of nuclear waste constitutes a severe challenge for the mankind for more than hundred thousand years. To reduce the radiotoxicity of the nuclear waste, the Accelerator Driven System (ADS) has been proposed. One of the most important issues of ADSs technology is the choice of the appropriate neutron spectrum for the transmutation of Minor Actinides (MA) and Long Lived Fission Products (LLFP). This report presents the analytical analyses obtained with the deterministic ERANOS code system for the YALINA facility within: (a) the collaboration between Argonne National Laboratory (ANL) of USA and the Joint Institute for Power and Nuclear Research (JIPNR) Sosny of Belarus; and (b) the IAEA coordinated research projects for accelerator driven systems (ADS). This activity is conducted as a part of the Russian Research Reactor Fuel Return (RRRFR) Program and the Global Threat Reduction Initiative (GTRI) of DOE/NNSA.
Date: August 31, 2009
Creator: Gohar, Y. & Aliberti, G.
System: The UNT Digital Library
Surveillance of Site A and Plot M, Report for 2008. (open access)

Surveillance of Site A and Plot M, Report for 2008.

The results of the environmental surveillance program conducted at Site A/Plot M in the Palos Forest Preserve area for Calendar Year 2008 are presented. Based on the results of the 1976-1978 radiological characterization of the site, a determination was made that a surveillance program be established. The characterization study determined that very low levels of hydrogen-3 (as tritiated water) had migrated from the burial ground and were present in two nearby hand pumped picnic wells. The current surveillance program began in 1980 and consists of sample collection and analysis of surface and subsurface water. The results of the analyses are used to (1) monitor the migration pathway of hydrogen-3 contaminated water from the burial ground (Plot M) to the hand-pumped picnic wells, (2) establish if other buried radionuclides have migrated, and (3) monitor for the presence of radioactive materials in the environment of the area. Hydrogen-3 in the Red Gate Woods picnic wells was still detected this year, but the average and maximum concentrations were significantly less than found earlier. Hydrogen-3 continues to be detected in a number of wells, boreholes, dolomite holes, and a surface stream. Analyses since 1984 have indicated the presence of low levels of strontium-90 in …
Date: May 7, 2009
Creator: Golchert, N. W.
System: The UNT Digital Library
Tests of the Hardware and Software for the Reconstruction of Trajectories in the Experiment MINERvA (open access)

Tests of the Hardware and Software for the Reconstruction of Trajectories in the Experiment MINERvA

MINERvA experiment has a highly segmented and high precision neutrino detector able to record events with high statistic (over 13 millions in a four year run). MINERvA uses FERMILAB NuMI beamline. The detector will allow a detailed study of neutrino-nucleon interactions. Moreover, the detector has a target with different materials allowing, for the first time, the study of nuclear effects in neutrino interactions. We present here the work done with the MINERvA reconstruction group that has resulted in: (a) development of new codes to be added to the RecPack package so it can be adapted to the MINERvA detector structure; (b) finding optimum values for two of the MegaTracker reconstruction package variables: PEcut = 4 (minimum number of photo electrons for a signal to be accepted) and Chi2Cut = 200 (maximum value of {chi}{sup 2} for a track to be accepted); (c) testing of the multi anode photomultiplier tubes used at MINERvA in order to determine the correlation between different channels and for checking the device's dark counts.
Date: May 1, 2009
Creator: Palomino Gallo, Jose Luis & /Rio de Janeiro, CBPF
System: The UNT Digital Library
Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues. (open access)

Impact of drought on U.S. steam electric power plant cooling water intakes and related water resource management issues.

This report was funded by the U.S. Department of Energy's (DOE's) National Energy Technology Laboratory (NETL) Existing Plants Research Program, which has an energy-water research effort that focuses on water use at power plants. This study complements their overall research effort by evaluating water availability at power plants under drought conditions. While there are a number of competing demands on water uses, particularly during drought conditions, this report focuses solely on impacts to the U.S. steam electric power plant fleet. Included are both fossil-fuel and nuclear power plants. One plant examined also uses biomass as a fuel. The purpose of this project is to estimate the impact on generation capacity of a drop in water level at U.S. steam electric power plants due to climatic or other conditions. While, as indicated above, the temperature of the water can impact decisions to halt or curtail power plant operations, this report specifically examines impacts as a result of a drop in water levels below power plant submerged cooling water intakes. Impacts due to the combined effects of excessive temperatures of the returned cooling water and elevated temperatures of receiving waters (due to high ambient temperatures associated with drought) may be examined in …
Date: April 3, 2009
Creator: Kimmell, T. A.; Veil, J. A. & Division, Environmental Science
System: The UNT Digital Library
Well-to-wheels energy use and greenhouse gas emissions analysis of plug-in hybrid electric vehicles. (open access)

Well-to-wheels energy use and greenhouse gas emissions analysis of plug-in hybrid electric vehicles.

Researchers at Argonne National Laboratory expanded the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model and incorporated the fuel economy and electricity use of alternative fuel/vehicle systems simulated by the Powertrain System Analysis Toolkit (PSAT) to conduct a well-to-wheels (WTW) analysis of energy use and greenhouse gas (GHG) emissions of plug-in hybrid electric vehicles (PHEVs). The WTW results were separately calculated for the blended charge-depleting (CD) and charge-sustaining (CS) modes of PHEV operation and then combined by using a weighting factor that represented the CD vehicle-miles-traveled (VMT) share. As indicated by PSAT simulations of the CD operation, grid electricity accounted for a share of the vehicle's total energy use, ranging from 6% for a PHEV 10 to 24% for a PHEV 40, based on CD VMT shares of 23% and 63%, respectively. In addition to the PHEV's fuel economy and type of on-board fuel, the marginal electricity generation mix used to charge the vehicle impacted the WTW results, especially GHG emissions. Three North American Electric Reliability Corporation regions (4, 6, and 13) were selected for this analysis, because they encompassed large metropolitan areas (Illinois, New York, and California, respectively) and provided a significant variation of marginal generation …
Date: March 31, 2009
Creator: Elgowainy, A.; Burnham, A.; Wang, M.; Molburg, J.; Rousseau, A. & Systems, Energy
System: The UNT Digital Library
Structured hints : extracting and abstracting domain expertise. (open access)

Structured hints : extracting and abstracting domain expertise.

We propose a new framework for providing information to help optimize domain-specific application codes. Its design addresses problems that derive from the widening gap between the domain problem statement by domain experts and the architectural details of new and future high-end computing systems. The design is particularly well suited to program execution models that incorporate dynamic adaptive methodologies for live tuning of program performance and resource utilization. This new framework, which we call 'structured hints', couples a vocabulary of annotations to a suite of performance metrics. The immediate target is development of a process by which a domain expert describes characteristics of objects and methods in the application code that would not be readily apparent to the compiler; the domain expert provides further information about what quantities might provide the best indications of desirable effect; and the interactive preprocessor identifies potential opportunities for the domain expert to evaluate. Our development of these ideas is progressing in stages from case study, through manual implementation, to automatic or semi-automatic implementation. In this paper we discuss results from our case study, an examination of a large simulation of a neural network modeled after the neocortex.
Date: March 16, 2009
Creator: Hereld, M.; Stevens, R.; Sterling, T.; Gao, G. R.; Science, Mathematics and Computer; Tech., California Inst. of et al.
System: The UNT Digital Library
Validation of the G-PASS code : status report. (open access)

Validation of the G-PASS code : status report.

Validation is the process of determining whether the models in a computer code can describe the important phenomena in applications of interest. This report describes past work and proposed future work for validating the Gas Plant Analyzer and System Simulator (G-PASS) code. The G-PASS code was developed for simulating gas reactor and chemical plant system behavior during operational transients and upset events. Results are presented comparing code properties, individual component models, and integrated system behavior against results from four other computer codes. Also identified are two experiment facilities nearing completion that will provide additional data for individual component and integrated system model validation. The main goal of the validation exercise is to ready a version of G-PASS for use as a tool in evaluating vendor designs and providing guidance to vendors on design directions in nuclear-hydrogen applications.
Date: March 12, 2009
Creator: Vilim, R. B.
System: The UNT Digital Library
Optimal explicit strong-stability-preserving general linear methods : complete results. (open access)

Optimal explicit strong-stability-preserving general linear methods : complete results.

This paper constructs strong-stability-preserving general linear time-stepping methods that are well suited for hyperbolic PDEs discretized by the method of lines. These methods generalize both Runge-Kutta (RK) and linear multistep schemes. They have high stage orders and hence are less susceptible than RK methods to order reduction from source terms or nonhomogeneous boundary conditions. A global optimization strategy is used to find the most efficient schemes that have low storage requirements. Numerical results illustrate the theoretical findings.
Date: March 3, 2009
Creator: Constantinescu, E. M.; Sandu, A.; Science, Mathematics and Computer & Univ., Virginia Polytechnic Inst. and State
System: The UNT Digital Library
Weather forecast-based optimization of integrated energy systems. (open access)

Weather forecast-based optimization of integrated energy systems.

In this work, we establish an on-line optimization framework to exploit detailed weather forecast information in the operation of integrated energy systems, such as buildings and photovoltaic/wind hybrid systems. We first discuss how the use of traditional reactive operation strategies that neglect the future evolution of the ambient conditions can translate in high operating costs. To overcome this problem, we propose the use of a supervisory dynamic optimization strategy that can lead to more proactive and cost-effective operations. The strategy is based on the solution of a receding-horizon stochastic dynamic optimization problem. This permits the direct incorporation of economic objectives, statistical forecast information, and operational constraints. To obtain the weather forecast information, we employ a state-of-the-art forecasting model initialized with real meteorological data. The statistical ambient information is obtained from a set of realizations generated by the weather model executed in an operational setting. We present proof-of-concept simulation studies to demonstrate that the proposed framework can lead to significant savings (more than 18% reduction) in operating costs.
Date: March 1, 2009
Creator: Zavala, V. M.; Constantinescu, E. M.; Krause, T. & Anitescu, M.
System: The UNT Digital Library
Physics design of a cold neutron source for KIPT neutron source facility. (open access)

Physics design of a cold neutron source for KIPT neutron source facility.

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of a neutron source facility. It is based on the use of an electron accelerator driven subcritical (ADS) facility with low enriched uranium fuel, using the existing electron accelerators at KIPT of Ukraine [1]. The neutron source of the subcritical assembly is generated from the interaction of 100-KW electron beam, which has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, with a natural uranium target [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Neutron beam experiments and material studies are also included. Over the past two-three decades, structures with characteristic lengths of 100 {angstrom} and correspondingly smaller vibrational energies have become increasingly important for both science and technology [3]. The characteristic dimensions of the microstructures can be well matched by neutrons with longer vibrational wavelength and lower energy. In the accelerator-driven subcritical facility, most of the neutrons are generated from fission reactions with energy in the MeV range. They are slowed down to the …
Date: February 17, 2009
Creator: Zhong, Z.; Gohar, Y. & Kellogg, R.
System: The UNT Digital Library
Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2007-November 2008. (open access)

Summary of operations and performance of the Utica aquifer and North Lake Basin Wetlands restoration project in December 2007-November 2008.

This document summarizes the performance of the groundwater restoration systems installed by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) at the former CCC/USDA grain storage facility in Utica, Nebraska, during the fourth year of system operation, from December 1, 2007, until November 30, 2008. Performance in earlier years was reported previously (Argonne 2005, 2006, 2008). In the project at Utica, the CCC/USDA is cooperating with multiple state and federal agencies to remove carbon tetrachloride contamination from a shallow aquifer underlying the town and to provide supplemental treated groundwater for use in the restoration of a nearby wetlands area. Argonne National Laboratory assisted the CCC/USDA by providing technical oversight for the aquifer restoration effort and facilities during this review period. This document presents overviews of the aquifer restoration facilities (Section 2) and system operations (Section 3). The report then describes groundwater production results (Section 4); groundwater treatment results (Section 5); and associated maintenance, system modifications, and costs during the review period (Section 6). Section 7 summarizes the present year of operation.
Date: January 23, 2009
Creator: LaFreniere, L. M.; Sedivy, R. A. & Division, Environmental Science
System: The UNT Digital Library
Fuel cycle comparison of distributed power generation technologies. (open access)

Fuel cycle comparison of distributed power generation technologies.

The fuel-cycle energy use and greenhouse gas (GHG) emissions associated with the application of fuel cells to distributed power generation were evaluated and compared with the combustion technologies of microturbines and internal combustion engines, as well as the various technologies associated with grid-electricity generation in the United States and California. The results were primarily impacted by the net electrical efficiency of the power generation technologies and the type of employed fuels. The energy use and GHG emissions associated with the electric power generation represented the majority of the total energy use of the fuel cycle and emissions for all generation pathways. Fuel cell technologies exhibited lower GHG emissions than those associated with the U.S. grid electricity and other combustion technologies. The higher-efficiency fuel cells, such as the solid oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC), exhibited lower energy requirements than those for combustion generators. The dependence of all natural-gas-based technologies on petroleum oil was lower than that of internal combustion engines using petroleum fuels. Most fuel cell technologies approaching or exceeding the DOE target efficiency of 40% offered significant reduction in energy use and GHG emissions.
Date: December 8, 2008
Creator: Elgowainy, A.; Wang, M. Q. & Systems, Energy
System: The UNT Digital Library
Water issues associated with heavy oil production. (open access)

Water issues associated with heavy oil production.

Crude oil occurs in many different forms throughout the world. An important characteristic of crude oil that affects the ease with which it can be produced is its density and viscosity. Lighter crude oil typically can be produced more easily and at lower cost than heavier crude oil. Historically, much of the nation's oil supply came from domestic or international light or medium crude oil sources. California's extensive heavy oil production for more than a century is a notable exception. Oil and gas companies are actively looking toward heavier crude oil sources to help meet demands and to take advantage of large heavy oil reserves located in North and South America. Heavy oil includes very viscous oil resources like those found in some fields in California and Venezuela, oil shale, and tar sands (called oil sands in Canada). These are described in more detail in the next chapter. Water is integrally associated with conventional oil production. Produced water is the largest byproduct associated with oil production. The cost of managing large volumes of produced water is an important component of the overall cost of producing oil. Most mature oil fields rely on injected water to maintain formation pressure during production. …
Date: November 28, 2008
Creator: Veil, J. A.; Quinn, J. J. & Division, Environmental Science
System: The UNT Digital Library
July 2008 Monitoring Results for Barnes, Kansas. (open access)

July 2008 Monitoring Results for Barnes, Kansas.

The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at Barnes, Kansas, during most of the interval 1949-1974. Carbon tetrachloride contamination was initially detected in 1986 in the town's public water supply wells. In 2006-2007, the CCC/USDA conducted a comprehensive targeted investigation at and near its former property in Barnes to characterize this contamination. Those results were reported previously (Argonne 2008a). In November 2007, the CCC/USDA began quarterly groundwater monitoring at Barnes. The monitoring is being conducted on behalf of the CCC/USDA by Argonne National Laboratory, in accord with the recommendations made in the report for the 2006-2007 targeted investigation (Argonne 2008a). The objective is to monitor the carbon tetrachloride contamination identified in the groundwater at Barnes. The sampling is presently conducted in a network of 28 individual monitoring wells (at 19 distinct locations), 2 public water supply wells, and 1 private well (Figure 1.1). The results of the 2006-2007 targeted investigation and the subsequent monitoring events in November 2007 (Argonne 2008b) and March 2008 (Argonne 2008c) demonstrated the presence of carbon tetrachloride contamination in groundwater at levels slightly exceeding the Kansas Department of Health and Environment (KDHE) Tier 2 risk-based screening level …
Date: November 20, 2008
Creator: LaFreniere, L. M.
System: The UNT Digital Library
Results of groundwater monitoring at Everest, Kansas, in April 2008. (open access)

Results of groundwater monitoring at Everest, Kansas, in April 2008.

On September 7, 2005, the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) presented a Scoping Memo (Argonne 2005) for preliminary consideration by the Kansas Department of Health and Environment (KDHE), suggesting possible remedial options for the carbon tetrachloride contamination in groundwater at Everest, Kansas. The suggested approaches were discussed by representatives of the KDHE, the CCC/USDA, and Argonne at the KDHE office in Topeka on September 8-9, 2005, along with other technical and logistic issues related to the Everest site. In response to these discussions, the KDHE recommended (KDHE 2005) evaluation of several remedial processes, either alone or in combination, as part of a Corrective Action Study (CAS) for Everest. The primary remedial processes suggested by the KDHE were the following: Hydraulic control by groundwater extraction with aboveground treatment; Air sparging (AS) coupled with soil vapor extraction (SVE) in large-diameter boreholes (LDBs); and Phytoremediation. As a further outcome of the 2005 meeting and as a precursor to development of a possible CAS, the CCC/USDA completed the following supplemental investigations at Everest to address several specific technical concerns discussed with the KDHE: (1) Construction of interpretive cross sections at strategic locations selected by the KDHE along the main …
Date: November 5, 2008
Creator: LaFreniere, L. M.
System: The UNT Digital Library
Perspectives on distributed computing : thirty people, four user types, and the distributed computing user experience. (open access)

Perspectives on distributed computing : thirty people, four user types, and the distributed computing user experience.

This report summarizes the methodology and results of a user perspectives study conducted by the Community Driven Improvement of Globus Software (CDIGS) project. The purpose of the study was to document the work-related goals and challenges facing today's scientific technology users, to record their perspectives on Globus software and the distributed-computing ecosystem, and to provide recommendations to the Globus community based on the observations. Globus is a set of open source software components intended to provide a framework for collaborative computational science activities. Rather than attempting to characterize all users or potential users of Globus software, our strategy has been to speak in detail with a small group of individuals in the scientific community whose work appears to be the kind that could benefit from Globus software, learn as much as possible about their work goals and the challenges they face, and describe what we found. The result is a set of statements about specific individuals experiences. We do not claim that these are representative of a potential user community, but we do claim to have found commonalities and differences among the interviewees that may be reflected in the user community as a whole. We present these as a series …
Date: October 15, 2008
Creator: Childers, L.; Liming, L.; Foster, I.; Science, Mathematics and Computer & Chicago, Univ. of
System: The UNT Digital Library
Guidelines for beamline and front-end radiation shielding design at the Advanced Photon Source. (open access)

Guidelines for beamline and front-end radiation shielding design at the Advanced Photon Source.

Shielding for the APS will be such that the individual radiation worker dose will be as low as reasonably achievable (ALARA). The ALARA goals for the APS are to keep the total of the work-related radiation exposure (exposure coming from other than natural or medical sources) as far below 500 person-mrem per year, collective total effective dose equivalent, as reasonably achievable. For an individual APS radiation worker, the goal is to keep the maximum occupational total effective dose equivalent of any one employee as far below 200 mrem/yr as reasonably achievable. The ALARA goal for APS beamline scientists is to keep the total of the work-related radiation exposure (exposure coming from other than natural or medical sources) as far below 100 person-mrem per year, collective total effective dose equivalent, as reasonably achievable. For an individual APS beamline scientist, the goal is to keep the maximum occupational total effective dose equivalent of any one scientist as far below 50 mrem/yr as reasonably achievable. The dose is actively monitored by the radiation monitors on the storage ring wall in each sector and by the frequent area surveys performed by the health physics personnel. For cases in which surveys indicate elevated hourly dose …
Date: September 11, 2008
Creator: Fernandez, P. & Division, X-Ray Science
System: The UNT Digital Library
Final report: results of the 2007 investigation of potential contamination at the former CCC/USDA facility in Powhattan, Kansas. (open access)

Final report: results of the 2007 investigation of potential contamination at the former CCC/USDA facility in Powhattan, Kansas.

The 2007 investigation of carbon tetrachloride and chloroform contamination at Powhattan, Kansas, was conducted at the request of the Kansas Department of Health and Environment (KDHE 2006a). The Environmental Science Division of Argonne National Laboratory implemented the investigation on behalf of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The primary purposes of the investigation were to evaluate potential contaminant source areas on the former CCC/USDA property, determine the horizontal and vertical extent of potential contamination, conduct groundwater monitoring, and provide recommendations for future action.
Date: August 15, 2008
Creator: LaFreniere, L. M.
System: The UNT Digital Library
Operation of the APS photoinjector drive laser system. (open access)

Operation of the APS photoinjector drive laser system.

The APS photoinjector drive laser system has been in operation since 1999 and is achieving a performance level exceeding the requirement of stable operation of the LEUTL FEL system. One remarkable number is the UV energy stability of better than 2% rms, sometimes less than 1% rms. This report summarizes the operation experience of the laser system and the improvements made along the way. We also outline the route of upgrade of the system and some frontier laser research and development opportunities in ultrabright electron beam generation.
Date: August 4, 2008
Creator: Li, Yuelin
System: The UNT Digital Library
Performance improvement options for the supercritical carbon dioxide brayton cycle. (open access)

Performance improvement options for the supercritical carbon dioxide brayton cycle.

The supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle is under development at Argonne National Laboratory as an advanced power conversion technology for Sodium-Cooled Fast Reactors (SFRs) as well as other Generation IV advanced reactors as an alternative to the traditional Rankine steam cycle. For SFRs, the S-CO{sub 2} Brayton cycle eliminates the need to consider sodium-water reactions in the licensing and safety evaluation, reduces the capital cost of the SFR plant, and increases the SFR plant efficiency. Even though the S-CO{sub 2} cycle has been under development for some time and optimal sets of operating parameters have been determined, those earlier development and optimization studies have largely been directed at applications to other systems such as gas-cooled reactors which have higher operating temperatures than SFRs. In addition, little analysis has been carried out to investigate cycle configurations deviating from the selected 'recompression' S-CO{sub 2} cycle configuration. In this work, several possible ways to improve S-CO{sub 2} cycle performance for SFR applications have been identified and analyzed. One set of options incorporates optimization approaches investigated previously, such as variations in the maximum and minimum cycle pressure and minimum cycle temperature, as well as a tradeoff between the component sizes and the …
Date: July 17, 2008
Creator: Moisseytsev, A. & Sienicki, J. J.
System: The UNT Digital Library
Status report on the Small Secure Transportable Autonomous Reactor (SSTAR) /Lead-cooled Fast Reactor (LFR) and supporting research and development. (open access)

Status report on the Small Secure Transportable Autonomous Reactor (SSTAR) /Lead-cooled Fast Reactor (LFR) and supporting research and development.

This report provides an update on development of a pre-conceptual design for the Small Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) plant concept and supporting research and development activities. SSTAR is a small, 20 MWe (45 MWt), natural circulation, fast reactor plant for international deployment concept incorporating proliferation resistance for deployment in non-fuel cycle states and developing nations, fissile self-sufficiency for efficient utilization of uranium resources, autonomous load following making it suitable for small or immature grid applications, and a high degree of passive safety further supporting deployment in developing nations. In FY 2006, improvements have been made at ANL to the pre-conceptual design of both the reactor system and the energy converter which incorporates a supercritical carbon dioxide Brayton cycle providing higher plant efficiency (44 %) and improved economic competitiveness. The supercritical CO2 Brayton cycle technology is also applicable to Sodium-Cooled Fast Reactors providing the same benefits. One key accomplishment has been the development of a control strategy for automatic control of the supercritical CO2 Brayton cycle in principle enabling autonomous load following over the full power range between nominal and essentially zero power. Under autonomous load following operation, the reactor core power adjusts itself to equal …
Date: June 23, 2008
Creator: Sienicki, J. J.; Moisseytsev, A.; Yang, W. S.; Wade, D. C.; Nikiforova, A.; Hanania, P. et al.
System: The UNT Digital Library
Summary of operations and performance of the Murdock site restoration project in 2007. (open access)

Summary of operations and performance of the Murdock site restoration project in 2007.

This document summarizes the performance of the groundwater and surface water restoration systems installed by the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) at the former CCC/USDA grain storage facility in Murdock, Nebraska, during the second full year of system operation, from January 1 through December 31, 2007. Performance in June 2005 through December 2006 was reported previously (Argonne 2007). In the Murdock project, several innovative technologies are being used to remove carbon tetrachloride contamination from a shallow aquifer underlying the town, as well as from water naturally discharged to the surface at the headwaters of a small creek (a tributary to Pawnee Creek) north of the town (Figure 1.1). The restoration activities at Murdock are being conducted by the CCC/USDA as a non-time-critical removal action under the regulatory authority and supervision of the U.S. Environmental Protection Agency (EPA), Region VII. Argonne National Laboratory assisted the CCC/USDA by providing technical oversight for the restoration effort and facilities during this review period. Included in this report are the results of all sampling and monitoring activities performed in accord with the EPA-approved Monitoring Plan for this site (Argonne 2006), as well as additional investigative activities conducted during the review …
Date: June 3, 2008
Creator: LaFreniere, L. M.
System: The UNT Digital Library
Status report on SHARP coupling framework. (open access)

Status report on SHARP coupling framework.

This report presents the software engineering effort under way at ANL towards a comprehensive integrated computational framework (SHARP) for high fidelity simulations of sodium cooled fast reactors. The primary objective of this framework is to provide accurate and flexible analysis tools to nuclear reactor designers by simulating multiphysics phenomena happening in complex reactor geometries. Ideally, the coupling among different physics modules (such as neutronics, thermal-hydraulics, and structural mechanics) needs to be tight to preserve the accuracy achieved in each module. However, fast reactor cores in steady state mode represent a special case where weak coupling between neutronics and thermal-hydraulics is usually adequate. Our framework design allows for both options. Another requirement for SHARP framework has been to implement various coupling algorithms that are parallel and scalable to large scale since nuclear reactor core simulations are among the most memory and computationally intensive, requiring the use of leadership-class petascale platforms. This report details our progress toward achieving these goals. Specifically, we demonstrate coupling independently developed parallel codes in a manner that does not compromise performance or portability, while minimizing the impact on individual developers. This year, our focus has been on developing a lightweight and loosely coupled framework targeted at UNIC …
Date: May 30, 2008
Creator: Caceres, A.; Tautges, T. J.; Lottes, J.; Fischer, P.; Rabiti, C.; Smith, M. A. et al.
System: The UNT Digital Library