Group Contribution Based Process Flowsheet Synthesis, Design and Modelling
DEFF Research Database (Denmark)
d'Anterroches, Loïc; Gani, Rafiqul
2004-01-01
This paper presents a process-group-contribution Method to model. simulate and synthesize a flowsheet. The process-group based representation of a flowsheet together with a process "property" model are presented. The process-group based synthesis method is developed on the basis of the computer...... aided molecular design methods and gives the ability to screen numerous process alternatives without the need to use the rigorous process simulation models. The process "property" model calculates the design targets for the generated flowsheet alternatives while a reverse modelling method (also...... developed) determines the design variables matching the target. A simple illustrative example highlighting the main features of the methodology is also presented....
Group Contribution Based Process Flowsheet Synthesis, Design and Modelling
DEFF Research Database (Denmark)
d'Anterroches, Loïc; Gani, Rafiqul
2005-01-01
In a group contribution method for pure component property prediction, a molecule is described as a set of groups linked together to form a molecular structure. In the same way, for flowsheet "property" prediction, a flowsheet can be described as a set of process-groups linked together to represent...... the flowsheet structure. Just as a functional group is a collection of atoms, a process-group is a collection of operations forming an "unit" operation or a set of "unit" operations. The link between the process-groups are the streams similar to the bonds that are attachments to atoms/groups. Each process-group...... provides a contribution to the "property" of the flowsheet, which can be performance in terms of energy consumption, thereby allowing a flowsheet "property" to be calculated, once it is described by the groups. Another feature of this approach is that the process-group attachments provide automatically...
Use of Flowsheet Monitoring to Perform Environmental Evaluation of Chemical Process Flowsheets
Flowsheet monitoring interfaces have been proposed to the Cape-Open Laboratories Network to enable development of applications that access to multiple parts of the flowsheet or its thermodynamic models, without interfering with the flowsheet itself. These flowsheet monitoring app...
Flowsheet model for the electrochemical treatment of liquid radioactive wastes. Final report
International Nuclear Information System (INIS)
Hobbs, D.T.; Prasad, S.; Farell, A.E.; Weidner, J.W.; White, R.E.
1995-01-01
The objective of this report is to describe the modeling and optimization procedure for the electrochemical removal of nitrates and nitrites from low level radioactive wastes. The simulation is carried out in SPEEDUP trademark, which is a state of the art flowsheet modeling package. The flowsheet model will provide a better understanding of the process and aid in the scale-up of the system. For example, the flowsheet model has shown that the electrochemical cell must be operated in batch mode to achieve 95 percent destruction. The flowsheet model is detailed in this report along with a systematic description of the batch optimization of the electrochemical cell. Results from two batch runs and one optimization run are also presented
Report on the flowsheet model for the electrochemical treatment of liquid radioactive wastes
International Nuclear Information System (INIS)
Hobbs, D.T.
1995-01-01
The objective of this report is to describe the modeling and optimization procedure for the electrochemical removal of nitrates and nitrites from low level radioactive wastes. The simulation is carried out in SPEEDUP trademark, which is a state of the art flowsheet modeling package. The flowsheet model will provide a better understanding of the process and aid in the scale-up of the system. For example, the flowsheet model has shown that the electrochemical cell must be operated in batch mode to achieve 95% destruction. The present status of the flowsheet model is detailed in this report along with a systematic description of the batch optimization of the electrochemical cell. Results from two batch runs and one optimization run are also presented
Modelling Template for the Development of the Process Flowsheet
DEFF Research Database (Denmark)
Fedorova, Marina; Gani, Rafiqul
2015-01-01
Models are playing important roles in design and analysis of chemicals/bio-chemicals based products and the processes that manufacture them. Model-based methods and tools have the potential to decrease the number of experiments, which can be expensive and time consuming, and point to candidates...... in connection to other modelling tools within the modelling framework are forming a user-friendly system, which will make the model development process easier and faster and provide the way for unified and consistent model documentation. The modeller can use the template for their specific problem or to extend...... models systematically, efficiently and reliably. In this way, development of products and processes can be faster, cheaper and very efficient. The developed modelling framework involves three main parts: 1) a modelling tool, that includes algorithms for model generation; 2) a template library, which...
Validation and Refinement of a Pain Information Model from EHR Flowsheet Data.
Westra, Bonnie L; Johnson, Steven G; Ali, Samira; Bavuso, Karen M; Cruz, Christopher A; Collins, Sarah; Furukawa, Meg; Hook, Mary L; LaFlamme, Anne; Lytle, Kay; Pruinelli, Lisiane; Rajchel, Tari; Settergren, Theresa Tess; Westman, Kathryn F; Whittenburg, Luann
2018-01-01
Secondary use of electronic health record (EHR) data can reduce costs of research and quality reporting. However, EHR data must be consistent within and across organizations. Flowsheet data provide a rich source of interprofessional data and represents a high volume of documentation; however, content is not standardized. Health care organizations design and implement customized content for different care areas creating duplicative data that is noncomparable. In a prior study, 10 information models (IMs) were derived from an EHR that included 2.4 million patients. There was a need to evaluate the generalizability of the models across organizations. The pain IM was selected for evaluation and refinement because pain is a commonly occurring problem associated with high costs for pain management. The purpose of our study was to validate and further refine a pain IM from EHR flowsheet data that standardizes pain concepts, definitions, and associated value sets for assessments, goals, interventions, and outcomes. A retrospective observational study was conducted using an iterative consensus-based approach to map, analyze, and evaluate data from 10 organizations. The aggregated metadata from the EHRs of 8 large health care organizations and the design build in 2 additional organizations represented flowsheet data from 6.6 million patients, 27 million encounters, and 683 million observations. The final pain IM has 30 concepts, 4 panels (classes), and 396 value set items. Results are built on Logical Observation Identifiers Names and Codes (LOINC) pain assessment terms and extend the need for additional terms to support interoperability. The resulting pain IM is a consensus model based on actual EHR documentation in the participating health systems. The IM captures the most important concepts related to pain. Schattauer GmbH Stuttgart.
Technetium removal: preliminary flowsheet options
International Nuclear Information System (INIS)
Eager, K.M.
1995-01-01
This document presents the results of a preliminary investigation into options for preliminary flowsheets for 99Tc removal from Hanford Site tank waste. A model is created to show the path of 99Tc through pretreatment to disposal. The Tank Waste Remediation (TWRS) flowsheet (Orme 1995) is used as a baseline. Ranges of important inputs to the model are developed, such as 99Tc inventory in the tanks and important splits through the TWRS flowsheet. Several technetium removal options are discussed along with sensitivities of the removal schemes to important model parameters
Energy Technology Data Exchange (ETDEWEB)
Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Zamecnik, J. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Missimer, D. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-03-08
Control of the REDuction/OXidation (REDOX) state of glasses containing high concentrations of transition metals, such as High Level Waste (HLW) glasses, is critical in order to eliminate processing difficulties caused by overly reduced or overly oxidized melts. Operation of a HLW melter at Fe^{+2}/ΣFe ratios of between 0.09 and 0.33, a range which is not overly oxidizing or overly reducing, helps retain radionuclides in the melt, i.e. long-lived radioactive ^{99}Tc species in the less volatile reduced Tc^{4+} state, ^{104}Ru in the melt as reduced Ru^{+4} state as insoluble RuO_{2}, and hazardous volatile Cr^{6+} in the less soluble and less volatile Cr^{+3} state in the glass. The melter REDOX control balances the oxidants and reductants from the feed and from processing additives such as antifoam. Currently, the Defense Waste Processing Facility (DWPF) is running a formic acid-nitric acid (FN) flowsheet where formic acid is the main reductant and nitric acid is the main oxidant. During decomposition formate and formic acid releases H_{2} gas which requires close control of the melter vapor space flammability. A switch to a nitric acid-glycolic acid (GN) flowsheet is desired as the glycolic acid flowsheet releases considerably less H_{2} gas upon decomposition. This would greatly simplify DWPF processing. Development of an EE term for glycolic acid in the GN flowsheet is documented in this study.
International Nuclear Information System (INIS)
Davison, J.E.; Eldershaw, C.E.
1992-01-01
This document forms the final report on a study of a coal-fired magnetohydrodynamic (MHD)/steam electric power generation system carried out by British Coal Corporation for the Commission of the European Communities. The study objective was to provide mass and energy balances and overall plant efficiency predictions for MHD to assist the Commission in their evaluation of advanced power generation technologies. In early 1990 the British Coal Corporation completed a study for the Commission in which a computer flowsheet modelling package was used to predict the performance of a conceptual air blown MHD plant. Since that study was carried out increasing emphasis has been placed on the possible need to reduce CO 2 emissions to counter the so-called greenhouse effect. Air blown MHD could greatly reduce CO 2 emissions per KWh by virtue of its high thermal efficiency. However, if even greater reductions in CO 2 emissions were required the CO 2 produced by coal combustion may have to be disposed of, for example into the deep ocean or underground caverns. To achieve this at minimum cost a concentrated CO 2 flue gas would be required. This could be achieved in an MHD plant by using a mixture of high purity oxygen and recycled CO 2 flue gas in the combustor. To assess this plant concept the European Commission awarded British Coal a contract to produce performance predictions using the access computer program
Modeling and flowsheet design of an Am separation process using TODGA and H{sub 4}TPAEN
Energy Technology Data Exchange (ETDEWEB)
Vanel, V.; Marie, C.; Montuir, M.; Boubals, N.; Sorel, C. [CEA, Centre de Marcoule, Nuclear Energy Division, Radiochemistry and Processes Department, Bagnols-sur-Ceze, F-30207 (France); Kaufholz, P.; Modolo, G. [Forschungszentrum Juelich GmbH, Institute of Energy and Climate Research, Nuclear Waste Management and Reactor Safety, D-52428 (Germany); Geist, A. [Karlsruher Institut fuer Technologie - KIT, Institut fuer Nukleare Entsorgung - INE, Karlsruhe (Germany)
2016-07-01
Recycling americium from spent fuels is an important consideration for the future nuclear fuel cycle, as americium is the main contributor to the long-term radiotoxicity and heat power of the final waste, after separation of uranium and plutonium using the PUREX process. The separation of americium alone from a PUREX raffinate can be achieved by co-extracting lanthanide (Ln(III)) and actinide (An(III)) cations into an organic phase containing the diglycolamide extractant TODGA, and then stripping Am(III) with selectivity towards Cm(III) and lanthanides. The water soluble ligand H{sub 4}TPAEN was tested to selectively strip Am from a loaded organic phase. Based on experimental data obtained by Juelich, NNL and CEA laboratories since 2013, a phenomenological model has been developed to simulate the behavior of americium, curium and lanthanides during their extraction by TODGA and their complexation by H{sub 4}TPAEN (complex stoichiometry, extraction and complexation constants, kinetics). The model was gradually implemented in the PAREX code and helped to narrow down the best operating conditions. Thus, the following 2 modifications of initial operating conditions were proposed: -) an increase in the concentration of TPAEN as much as the solubility limit allows, and -) an improvement of the lanthanide scrubbing from the americium flow by adding nitrates to the aqueous phase. A qualification of the model was begun by comparing on the one hand constants determined with the model to those measured experimentally, and on the other hand, simulation results and experimental data on new independent batch experiments. A first sensitivity analysis identified which parameter has the most dominant effect on the process. A flowsheet was proposed for a spiked test in centrifugal contactors performed with a simulated PUREX raffinate with trace amounts of Am and Cm. If the feasibility of the process is confirmed, the results of this test will be used to consolidate the model and to
Process Options Description for Vitrification Flowsheet Model of INEEL Sodium Bearing Waste
Energy Technology Data Exchange (ETDEWEB)
Nichols, Todd Travis; Taylor, Dean Dalton; Lauerhass, Lance; Barnes, Charles Marshall
2001-02-01
The purpose of this document is to provide the technical information to Savannah River Site (SRS) personnel that is required for the development of a basic steady-state process simulation of the vitrification treatment train of sodium bearing waste (SBW) at Idaho National Engineering and nvironmental Laboratory (INEEL). INEEL considers simulation to have an important role in the integration/optimization of treatment process trains for the High Level Waste (HLW) Program. This project involves a joint Technical Task Plan (TTP ID77WT31, Subtask C) between SRS and INEEL. The work scope of simulation is different at the two sites. This document addresses only the treatment of SBW at INEEL. The simulation model(s) is to be built by SRS for INEEL in FY-2001.
Process Options Description for Vitrification Flowsheet Model of INEEL Sodium Bearing Waste
Energy Technology Data Exchange (ETDEWEB)
Nichols, T.T.; Taylor, D.D.; Lauerhass, L.; Barnes, C.M.
2002-02-21
The technical information required for the development of a basic steady-state process simulation of the vitrification treatment train of sodium bearing waste (SBW) at Idaho National Engineering and Environmental Laboratory (INEEL) is presented. The objective of the modeling effort is to provide the predictive capability required to optimize an entire treatment train and assess system-wide impacts of local changes at individual unit operations, with the aim of reducing the schedule and cost of future process/facility design efforts. All the information required a priori for engineers to construct and link unit operation modules in a commercial software simulator to represent the alternative treatment trains is presented. The information is of a mid- to high-level nature and consists of the following: (1) a description of twenty-four specific unit operations--their operating conditions and constraints, primary species and key outputs, and the initial modeling approaches that will be used in the first year of the simulation's development; (2) three potential configurations of the unit operations (trains) and their interdependencies via stream connections; and (3) representative stream compositional makeups.
Process Options Description for Vitrification Flowsheet Model of INEEL Sodium Bearing Waste
International Nuclear Information System (INIS)
Nichols, T.T.; Taylor, D.D.; Lauerhass, L.; Barnes, C.M.
2002-01-01
The technical information required for the development of a basic steady-state process simulation of the vitrification treatment train of sodium bearing waste (SBW) at Idaho National Engineering and Environmental Laboratory (INEEL) is presented. The objective of the modeling effort is to provide the predictive capability required to optimize an entire treatment train and assess system-wide impacts of local changes at individual unit operations, with the aim of reducing the schedule and cost of future process/facility design efforts. All the information required a priori for engineers to construct and link unit operation modules in a commercial software simulator to represent the alternative treatment trains is presented. The information is of a mid- to high-level nature and consists of the following: (1) a description of twenty-four specific unit operations--their operating conditions and constraints, primary species and key outputs, and the initial modeling approaches that will be used in the first year of the simulation's development; (2) three potential configurations of the unit operations (trains) and their interdependencies via stream connections; and (3) representative stream compositional makeups
A technetium rejection flowsheet
International Nuclear Information System (INIS)
Baker, R.; Miles, J.H.; Roberts, P.T.
1990-01-01
A single contactor unit has been designed which enables Tc to be removed from a TBP/diluent stream bearing U and Pu, by means of a 5M HNO 3 wash. A Tc waste stream is produced which is virtually free from U and Pu. The flowsheet has been tested firstly with U and Tc, then with U, Pu and Tc, and finally in a highly active facility with real PWR fuel solution. About 97% of the Tc was removed from the organic phase and U and Pu levels in the Tc waste have usually been below 0.04% of those in the product stream. (author)
Reprocessing flowsheet and material balance for MEU spent fuel
International Nuclear Information System (INIS)
Abraham, L.
1978-10-01
In response to nonproliferation concerns, the high-temperature gas-cooled reactor (HTGR) Fuel Recycle Development Program is investigating the processing requirements for a denatured medium-enriched uranium--thorium (MEU/Th) fuel cycle. Prior work emphasized the processing requirements for a high-enriched uranium--thorium (HEU/Th) fuel cycle. This report presents reprocessing flowsheets for an HTGR/MEU fuel recycle base case. Material balance data have been calculated for reprocessing of spent MEU and recycle fuels in the HTGR Recycle Reference Facility (HRRF). Flowsheet and mass flow effects in MEU-cycle reprocessing are discussed in comparison with prior HEU-cycle flowsheets
Hot Experimental Facility reference flowsheet
International Nuclear Information System (INIS)
North, E.D.
1982-01-01
This paper is a useful set of background information of HEF flowsheets, although many changes have been made in the past three years. The HEF reference flowsheet is a modified high-acid PUREX flowsheet capable of operating in the coprocessing mode or with full partitioning of U and Pu. Adequate decontamination factors are provided to purify high-burnup, fast breeder-reactor fuels to levels required for recycle back to a fuel fabrication facility. Product streams are mixed U-Pu oxide and uranium oxide. No contaminated liquid wastes are intentionally discharged to the environment. All wastes are solidified and packaged for appropriate disposal. Acid and water are recovered for internal recycle. Excess water is treated and discharged from the plant stack. Several changes have been made in the reference flowsheet since that time, and these are noted briefly
Heat integrated ethanol dehydration flowsheets
Energy Technology Data Exchange (ETDEWEB)
Hutahaean, L.S.; Shen, W.H.; Brunt, V. Van [Univ. of South Carolina, Columbia, SC (United States)
1995-04-01
zA theoretical evaluation of heat-integrated heterogeneous-azeotropic ethanol-water distillation flowsheets is presented. Simulations of two column flowsheets using several different hydrocarbon entrainers reveal a region of potential heat integration and substantial reduction in operating energy. In this paper, methods for comparing hydrocarbon entrainers are shown. Two aspects of entrainers are related to operating and capital costs. The binary azeotropic composition of the entrainer-ethanol mixture is related to the energy requirements of the flowsheet. A temperature difference in the azeotrophic column is related to the size of the column and overall process staging requirements. Although the hydrophobicity of an entrainer is essential for specification of staging in the dehydration column, no substantial increase in operating energy results from an entrainer that has a higher water content. Likewise, liquid-liquid equilibria between several entrainer-ethanol-water mixtures have no substantial effect on either staging or operation. Rather, increasing the alcohol content of the entrainer-ethanol azeotrope limits its recovery in the dehydration column, and increases the recycle and reflux streams. These effects both contribute to increasing the separation energy requirements and reducing the region of potential heat integration. A cost comparison with a multieffect extractive distillation flowsheet reveals that the costs are comparable; however, the extractive distillation flowsheet is more cost effective as operating costs increase.
A new flowsheeting tool for flue gas treating
van Elk, E. P.; Arendsen, A. R. J.; Versteeg, G. F.
2009-01-01
A new flowsheeting tool, specifically designed for steady-state simulation of acid gas treating processes, has been developed. The models implemented in the new tool combine all issues relevant for the design, optimization and analysis of acid gas treating processes, including post-combustion and
Mixed Waste Treatment Project: Computer simulations of integrated flowsheets
International Nuclear Information System (INIS)
Dietsche, L.J.
1993-12-01
The disposal of mixed waste, that is waste containing both hazardous and radioactive components, is a challenging waste management problem of particular concern to DOE sites throughout the United States. Traditional technologies used for the destruction of hazardous wastes need to be re-evaluated for their ability to handle mixed wastes, and in some cases new technologies need to be developed. The Mixed Waste Treatment Project (MWTP) was set up by DOE's Waste Operations Program (EM30) to provide guidance on mixed waste treatment options. One of MWTP's charters is to develop flowsheets for prototype integrated mixed waste treatment facilities which can serve as models for sites developing their own treatment strategies. Evaluation of these flowsheets is being facilitated through the use of computer modelling. The objective of the flowsheet simulations is to provide mass and energy balances, product compositions, and equipment sizing (leading to cost) information. The modelled flowsheets need to be easily modified to examine how alternative technologies and varying feed streams effect the overall integrated process. One such commercially available simulation program is ASPEN PLUS. This report contains details of the Aspen Plus program
Enriched uranium recovery flowsheet improvements
International Nuclear Information System (INIS)
Holt, D.L.
1986-01-01
Savannah River uses 7.5% TBP to recover and purify enriched uranium. Adequate decontamination from fission products is necessary to reduce personnel exposure and to ensure that the enriched uranium product meets specifications. Initial decontamination of the enriched uranium from the fission products is carried out in the 1A bank, 16 stages of mixer-settlers. Separation of the enriched uranium from the fission product, 95 Zr, has been adequate, but excessive solvent degradation caused by the long phase contact times in the mixer-settlers has limited the 95 Zr decontamination factor (DF). An experimental program is investigating the replacement of the current 1A bank with either centrifugal contactors or a combination of centrifugal contactors and mixer-settlers. Experimental work completed has compared laboratory-scale centrifugal contactors and mixer-settlers for 95 Zr removal efficiencies. Feed solutions spiked with actual plant solutions were used. The 95 Zr DF was significantly better in the mixer-settlers than in the centrifugal contactors. As a result of this experimental study, a hybrid equipment flowsheet has been proposed for plant use. The hybrid equipment flowsheet combines the advantages of both types of solvent extraction equipment. Centrifugal contactors would be utilized in the extraction and initial scrub sections, followed by additional scrub stages of mixer-settlers
International Nuclear Information System (INIS)
Homma, Shunji; Sakamoto, Susumu; Takanashi, Mitsuhiro; Nammo, Akihiko; Satoh, Yoshihiro; Soejima, Takayuki; Koga, Jiro; Matsumoto, Shiro
1995-01-01
A computer aided process flowsheet design and analysis system, COMPAS has been developed in order to carry out the flowsheet calculation on the process flow diagram of nuclear fuel reprocessing. All of equipments, such as dissolver, mixer-settler, and so on, in the process flowsheet diagram are graphically visualized as icon on a bitmap display of UNIX workstation. Drawing of a flowsheet can be carried out easily by the mouse operation. Not only a published numerical simulation code but also a user's original one can be used on the COMPAS. Specifications of the equipment and the concentration of components in the stream displayed as tables can be edited by a computer user. Results of calculation can be also displayed graphically. Two examples show that the COMPAS is applicable to decide operating conditions of Purex process and to analyze extraction behavior in a mixer-settler extractor. (author)
International Nuclear Information System (INIS)
Williams, D.F.; Knauer, J.B.; O'Kelley, G.D.; Wiggins, J.T.; Porter, C.E.
1992-01-01
The production of large quantities of high specific activity 63 Ni (>10Ci/g) requires both a highly enriched 62 Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products (mainly transition metals) can be easily removed as chloride complexes during anion exchange, chromium, present as 51 Cr, and manganese, present as 54 Mn, are exceptions and require solvent extraction of the in-cell product to achieve the desired purity. In addition to summarizing the current development and production experience, optimized flowsheets are discussed
Application of structured flowsheets to global evaluation of tank waste processing alternatives
International Nuclear Information System (INIS)
Jansen, G.; Knutson, B.J.; Niccoli, L.G.; Frank, D.D.
1994-01-01
Remediation of the Hanford waste tanks requires integration of chemical technologies and evaluation of alternatives from the perspective of the overall Hanford cleanup purpose. The use of Design/IDEF (R) logic to connect chemical process functions to the overall cleanup mission in the Hanford Strategic Analysis (HSA) and to Aspen Plus (R) process models can show the effect of each process step on global performance measures such as safety, cost, and public perception. This hybrid of chemical process analysis and systems engineering produces structured material balance flowsheets at any level of process aggregation within the HSA. Connectivity and consistent process and stream nomenclature are automatically transferred between detailed process models, the HSA top purpose, and the global material balance flowsheet evaluation. Applications to separation processes is demonstrated for a generic Truex-Sludge Wash flowsheet with many process options and for the aggregation of a Clean Option flowsheet from a detailed chemical process level to a global evaluation level
Equilibrium fission model calculations
International Nuclear Information System (INIS)
Beckerman, M.; Blann, M.
1976-01-01
In order to aid in understanding the systematics of heavy ion fission and fission-like reactions in terms of the target-projectile system, bombarding energy and angular momentum, fission widths are calculated using an angular momentum dependent extension of the Bohr-Wheeler theory and particle emission widths using angular momentum coupling
Low temperature dissolution flowsheet for plutonium metal
Energy Technology Data Exchange (ETDEWEB)
Daniel, W. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Almond, P. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Rudisill, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-05-01
The H-Canyon flowsheet used to dissolve Pu metal for PuO_{2} production utilizes boiling HNO_{3}. SRNL was requested to develop a complementary dissolution flowsheet at two reduced temperature ranges. The dissolution and H_{2} generation rates of Pu metal were investigated using a dissolving solution at ambient temperature (20-30 °C) and for an intermediate temperature of 50-60 °C. Additionally, the testing included an investigation of the dissolution rates and characterization of the off-gas generated from the ambient temperature dissolution of carbon steel cans and the nylon bags that contain the Pu metal when charged to the dissolver.
Purex Process Improvements for Pu and NP Control in Total Actinide Recycle Flowsheets
International Nuclear Information System (INIS)
Birkett, J.E.; Carrott, M.J.; Crooks, G.; Fox, O.D.; Maher, C.J.; Taylor, R.J.; Woodhead, D.A.
2006-01-01
Significant improvements are required in the Purex process to optimise it for Advanced Fuel Cycles. Two key challenges we have identified are, firstly, developing more efficient methods for U/Pu separations especially at elevated Pu concentrations and, secondly, improving recovery, control and routing of Np in a modified Purex process. A series of Purex-like flowsheets for improved Pu separations based on hydroxamic acids and are reported. Purex-like flowsheets have been tested on a glovebox-housed 30-stage miniature centrifugal contactor train. A series of trials have been performed to demonstrate the processing of feeds with varying Pu contents ranging from 7 - 40% by weight. These flowsheets have demonstrated hydroxamic acids are excellent reagents for complexant stripping of Pu being able to achieve high decontamination factors (DF) on both the U and Pu product streams and co - recover Np with Pu. The advantages of a complexant-based approach are shown to be especially relevant when AFC scenarios are considered, where the Pu content of the fuel is expected to b e significantly higher. Recent results towards modifying the Purex process to improve recovery and control of Np in short residence time contactors are reported. Work on the development of chemical and process models to describe the complicated behaviour of Np under primary separation conditions (i.e. the HA extraction contactor) is described. To test the performance of the model a series of experiments were performed including testing of flowsheets on a fume-hood housed miniature centrifugal contactor train. The flowsheet was designed to emulate the conditions of a primar y separations contactor with the Np split between the U-solvent product and aqueous raffinate. In terms of Np routing the process model showed good agreement with flowsheet trial however much further work is required to fully understand this complex system. (authors)
Method for innovative synthesis-design of chemical process flowsheets
DEFF Research Database (Denmark)
Kumar Tula, Anjan; Gani, Rafiqul
Chemical process synthesis-design involve the identification of the processing route to reach a desired product from a specified set of raw materials, design of the operations involved in the processing route, the calculations of utility requirements, the calculations of waste and emission...... to the surrounding and many more. Different methods (knowledge-based [1], mathematical programming [2], hybrid, etc.) have been proposed and are also currently employed to solve these synthesis-design problems. D’ Anterroches [3] proposed a group contribution based approach to solve the synthesis-design problem...... of chemical processes, where, chemical process flowsheets could be synthesized in the same way as atoms or groups of atoms are synthesized to form molecules in computer aided molecular design (CAMD) techniques [4]. That, from a library of building blocks (functional process-groups) and a set of rules to join...
Computer Aided Flowsheet Design using Group Contribution Methods
DEFF Research Database (Denmark)
Bommareddy, Susilpa; Eden, Mario R.; Gani, Rafiqul
2011-01-01
In this paper, a systematic group contribution based framework is presented for synthesis of process flowsheets from a given set of input and output specifications. Analogous to the group contribution methods developed for molecular design, the framework employs process groups to represent...... information of each flowsheet to minimize the computational load and information storage. The design variables for the selected flowsheet(s) are identified through a reverse simulation approach and are used as initial estimates for rigorous simulation to verify the feasibility and performance of the design....
Tank SY-102 remediation project: Flowsheet and conceptual design report
Energy Technology Data Exchange (ETDEWEB)
Yarbro, S.L.; Punjak, W.A.; Schreiber, S.B.; Dunn, S.L.; Jarvinen, G.D.; Marsh, S.F.; Pope, N.G.; Agnew, S.; Birnbaum, E.R.; Thomas, K.W.; Ortic, E.A.
1994-01-01
The US Department of Energy established the Tank Waste Remediation System (TWRS) to safely manage and dispose of radioactive waste stored in underground tanks on the Hanford Site. A major program in TWRS is pretreatment which was established to process the waste prior to disposal. Pretreatment is needed to resolve tank safety issues and to separate wastes into high-level and low-level fractions for subsequent immobilization and disposal. There is a fixed inventory of actinides and fission products in the tank which must be prepared for disposal. By segregating the actinides and fission products from the bulk of the waste, the tank`s contents can be effectively managed. Due to the high public visibility and environmental sensitivity of this problem, real progress and demonstrated efforts toward addressing it must begin as soon as possible. As a part of this program, personnel at the Los Alamos National Laboratory (LANL) have developed and demonstrated a flowsheet to remediate tank SY-102 which is located in the 200 West Area and contains high-level radioactive waste. This report documents the results of the flowsheet demonstrations performed with simulated, but radioactive, wastes using an existing glovebox line at the Los Alamos Plutonium Facility. The tank waste was characterized using both a tank history approach and an exhaustive evaluation of the available core sample analyses. This report also presents a conceptual design complete with a working material flow model, a major equipment list, and cost estimates.
Tank SY-102 remediation project: Flowsheet and conceptual design report
International Nuclear Information System (INIS)
Yarbro, S.L.; Punjak, W.A.; Schreiber, S.B.; Dunn, S.L.; Jarvinen, G.D.; Marsh, S.F.; Pope, N.G.; Agnew, S.; Birnbaum, E.R.; Thomas, K.W.; Ortic, E.A.
1994-01-01
The US Department of Energy established the Tank Waste Remediation System (TWRS) to safely manage and dispose of radioactive waste stored in underground tanks on the Hanford Site. A major program in TWRS is pretreatment which was established to process the waste prior to disposal. Pretreatment is needed to resolve tank safety issues and to separate wastes into high-level and low-level fractions for subsequent immobilization and disposal. There is a fixed inventory of actinides and fission products in the tank which must be prepared for disposal. By segregating the actinides and fission products from the bulk of the waste, the tank's contents can be effectively managed. Due to the high public visibility and environmental sensitivity of this problem, real progress and demonstrated efforts toward addressing it must begin as soon as possible. As a part of this program, personnel at the Los Alamos National Laboratory (LANL) have developed and demonstrated a flowsheet to remediate tank SY-102 which is located in the 200 West Area and contains high-level radioactive waste. This report documents the results of the flowsheet demonstrations performed with simulated, but radioactive, wastes using an existing glovebox line at the Los Alamos Plutonium Facility. The tank waste was characterized using both a tank history approach and an exhaustive evaluation of the available core sample analyses. This report also presents a conceptual design complete with a working material flow model, a major equipment list, and cost estimates
First-cycle studies of coprocessing flowsheets
International Nuclear Information System (INIS)
Gray, J.H.
1981-06-01
Selected portions of two coprocessing flowsheets developed for use at the Barnwell Nuclear Fuel Plant (BNFP) have been tested in the laboratory with uranium, plutonium, and fission products. Processing conditions and stream compositions for first cycle extraction and uranium-plutonium partitioning in an electropulse column were controlled to examine the behavior of nitric acid, uranium, plutonium, and fission products during coprocessing. The ability to adapt coprocessing technology for use in the BNFP reprocessing facility was successful for first cycle extraction and partition. The only process adjustment involved a reduction in nitric acid concentration to attain proper uranium to plutonium ratios
A flowsheet for a wave power unit
Energy Technology Data Exchange (ETDEWEB)
Sobierajski, E.; Kasperowicz, Z.
1984-01-01
A flowsheet is examined for a wave power unit designed to produce electricity, for flooding or drying a coastal zone, cleaning or protecting water areas of ports from sand deposits. The unit includes a vertical cylinder attached to the sea floor with input and output water ducts and valves. The cylinder has a rod with piston that is actuated through a flexible cable by float arranged next to the cylinder. The water injected under pressure into the pressure pipe can be used directly or as an intermediate energy source.
Shafiee, Alireza; Arab, Mobin; Lai, Zhiping; Liu, Zongwen; Abbas, Ali
2016-01-01
In optimization-based process flowsheet synthesis, optimization methods, including genetic algorithms (GA), are used as advantageous tools to select a high performance flowsheet by ‘screening’ large numbers of possible flowsheets. In this study, we
Evaluation of quartz melt rate furnace with the nitric-glycolic flowsheet
Energy Technology Data Exchange (ETDEWEB)
Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Miller, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-08-03
The Savannah River National Laboratory (SRNL) was tasked to support validation of the Defense Waste Processing Facility (DWPF) melter offgas flammability model for the Nitric-Glycolic (NG) flowsheet. The work is supplemental to the Cold Cap Evaluation Furnace (CEF) testing conducted in 20141 and the Slurry-fed Melt Rate Furnace (SMRF) testing conducted in 20162 that supported Deliverable 4 of the DWPF & Saltstone Facility Engineering Technical Task Request (TTR).3 The Quartz Melt Rate Furnace (QMRF) was evaluated as a bench-scale scoping tool to potentially be used in lieu of or simply prior to the use of the larger-scale SMRF or CEF. The QMRF platform has been used previously to evaluate melt rate behavior and offgas compositions of DWPF glasses prepared from the Nitric-Formic (NF) flowsheet but not for the NG flowsheet and not with continuous feeding.4 The overall objective of the 2016-2017 testing was to evaluate the efficacy of the QMRF as a lab-scale platform for steady state, continuously fed melter testing with the NG flowsheet as an alternative to more expensive and complex testing with the SMRF or CEF platforms.
Flowsheet development for HTGR fuel reprocessing
International Nuclear Information System (INIS)
Baxter, B.; Benedict, G.E.; Zimmerman, R.D.
1976-01-01
Development studies to date indicate that the HTGR fuel blocks can be effectively crushed with two stages of eccentric jaw crushing, followed by a double-roll crusher, a screener and an eccentrically mounted single-roll crusher for oversize particles. Burner development results indicate successful long-term operation of both the primary and secondary fluidized-bed combustion systems can be performed with the equipment developed in this program. Aqueous separation development activities have centered on adapting known Acid-Thorex processing technology to the HTGR reprocessing task. Significant progress has been made on dissolution of burner ash, solvent extraction feed preparation, slurry transfer, solids drying and solvent extraction equipment and flowsheet requirements
Flowsheet finalisation for immobilisation of SGHWR wastes
International Nuclear Information System (INIS)
Lee, D.J.
1984-09-01
This report summarises research and development work carried out during the year ended March 1983 on the programme for cementing the Winfrith Reactor (SGHWR) sludge. Further results from the characterisation programme are reported, together with data from the cementation programme. Formulations based on Ordinary Portland Cement (OPC), ground granulated blast furnace slag (BFS) and Pulverised Fuel Ash (PFA) have been tested. The results show that a blend of 90% BFS/10% OPC by weight, gives the best properties. Chemical pretreatment as a method for producing a stable waste form is discussed. A dewatering pretreatment to provide a sludge suitable for direct cementation is also outlined. A flowsheet for cementing the SGHWR sludge is proposed based on these laboratory and pilot scale studies. The major components required for the active plant are identified and provisional plant layouts are given. (author)
Integrated HLW Conceptual Process Flowsheet(s) for the Crystalline Silicotitanate Process SRDF-98-04
International Nuclear Information System (INIS)
Jacobs, R.A.
1998-01-01
The Strategic Research and Development Fund (SRDF) provided funds to develop integrated conceptual flowsheets and material balances for a CST process as a potential replacement for, or second generation to, the ITP process. This task directly supports another SRDF task: Glass Form for HLW Sludge with CST, SRDF-98-01, by M. K. Andrews which seeks to further develop sludge/CST glasses that could be used if the ITP process were replaced by CST ion exchange. The objective of the proposal was to provide flowsheet support for development and evaluation of a High Level Waste Division process to replace ITP. The flowsheets would provide a conceptual integrated material balance showing the impact on the HLW division. The evaluation would incorporate information to be developed by Andrews and Harbour on CST/DWPF glass formulations and provide the bases for evaluating the economic impact of the proposed replacement process. Coincident with this study, the Salt Disposition Team began its evaluation of alternatives for disposition of the HLW salts in the SRS waste tanks. During that time, the CST IX process was selected as one of four alternatives (of eighteen Phase II alternatives) for further evaluation during Phase III
An evaluation of five flowsheets for the recovery of uranium from Wits leach pulps
International Nuclear Information System (INIS)
Boydell, D.W.; Viljoen, E.B.
1978-01-01
This article evaluates five flowsheets for uranium recovery and an incremental net present value is calculated for each by the discounting of cash flows at 25 per cent per year over a projected life of 15 years. The highest net present value results from the circuit that employs belt filtration followed by continuous ion exchange, plus solvent extraction, in the particular case of the material used in the examples
Nitric acid flowsheet with late wash PHA testing
International Nuclear Information System (INIS)
Zamecnik, J.R.
1993-01-01
This Task Technical Plan outlines the activities to be conducted in the Integrated DWPF Melter System (IDMS) in ongoing support of the Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) utilizing the Nitric Acid Flowsheet in the Sludge Receipt and Adjustment Tank (SRAT) and Precipitate Hydrolysis Aqueous (PHA) produced by the Late Wash Flowsheet. The IDMS facility is to be operated over a series of runs (2 to 4) using the Nitric Acid Flowsheet. The PHA will be produced with the Late Wash Flowsheet in the Precipitate Hydrolysis Experimental Facility (PHEF). All operating conditions shall simulate the expected DWPF operating conditions as closely as possible. The task objectives are to perform at least two IDMS runs with as many operating conditions as possible at nominal DWPF conditions. The major purposes of these runs are twofold: verify that the combined Late Wash and Nitric Acid flowsheets produce glass of acceptable quality without additional changes to process equipment, and determine the reproducibility of data from run to run. These runs at nominal conditions will be compared to previous runs made with PHA produced from the Late Wash flowsheet and with the Nitric Acid flowsheet in the SRAT (Purex 4 and Purex 5)
An equation oriented approach to steady state flowsheeting of methanol synthesis loop
International Nuclear Information System (INIS)
Fathikalajahi, J.; Baniadam, M.; Rahimpour, M.R.
2008-01-01
An equation-oriented approach was developed for steady state flowsheeting of a commercial methanol plant. The loop consists of fixed bed reactor, flash separator, preheater, coolers, and compressor. For steady sate flowsheeting of the plant mathematical model of reactor and other units are needed. Reactor used in loop is a Lurgi type and its configuration is rather complex. Previously reactor and flash separator are modeled as two important units of plant. The model is based on mass and energy balances in each equipment and utilizing some auxiliary equations such as rate of reaction and thermodynamics model for activity coefficients of liquid. In order to validate the mathematical model for the synthesis loop, some simulation data were performed using operating conditions and characteristics of the commercial plant. The good agreement between the steady state simulation results and the plant data shows the validity of the model
FRACTIONAL CRYSTALLIZATION FLOWSHEET TESTS WITH ACTUAL TANK WASTE
International Nuclear Information System (INIS)
HERTING, D.L.
2006-01-01
Laboratory-scale flowsheet tests of the fractional crystallization process were conducted with actual tank waste samples in a hot cell at the 222-S Laboratory. The process is designed to separate medium-curie liquid waste into a low-curie stream for feeding to supplemental treatment and a high-curie stream for double-shell tank storage. Separations criteria (for Cs-137 sulfate, and sodium) were exceeded in all three of the flowsheet tests that were performed
Recommendation of ruthenium source for sludge batch flowsheet studies
Energy Technology Data Exchange (ETDEWEB)
Woodham, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-09-13
Included herein is a preliminary analysis of previously-generated data from sludge batches 7a, 7b, 8, and 9 sludge simulant and real-waste testing, performed to recommend a form of ruthenium for future sludge batch simulant testing under the nitric-formic flowsheet. Focus is given to reactions present in the Sludge Receipt and Adjustment Tank cycle, given that this cycle historically produces the most changes in chemical composition during Chemical Process Cell processing. Data is presented and analyzed for several runs performed under the nitric-formic flowsheet, with consideration given to effects on the production of hydrogen gas, nitrous oxide gas, consumption of formate, conversion of nitrite to nitrate, and the removal and recovery of mercury during processing. Additionally, a brief discussion is given to the effect of ruthenium source selection under the nitric-glycolic flowsheet. An analysis of data generated from scaled demonstration testing, sludge batch 9 qualification testing, and antifoam degradation testing under the nitric-glycolic flowsheet is presented. Experimental parameters of interest under the nitric-glycolic flowsheet include N2O production, glycolate destruction, conversion of glycolate to formate and oxalate, and the conversion of nitrite to nitrate. To date, the number of real-waste experiments that have been performed under the nitric-glycolic flowsheet is insufficient to provide a complete understanding of the effects of ruthenium source selection in simulant experiments with regard to fidelity to real-waste testing. Therefore, a determination of comparability between the two ruthenium sources as employed under the nitric-glycolic flowsheet is made based on available data in order to inform ruthenium source selection for future testing under the nitric-glycolic flowsheet.
Integration of SWPF into the DWPF Flowsheet: Gap Analysis and Test Matrix Development
Energy Technology Data Exchange (ETDEWEB)
Peeler, D. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2014-12-10
Based on Revision 19 of the High Level Waste (HLW) System Plan, it is anticipated that the Salt Waste Processing Facility (SWPF) will be integrated into the Defense Waste Processing Facility (DWPF) flowsheet in October 2018 (or with Sludge Batch 11 (SB11)). Given that, Savannah River Remediation (SRR) has requested a technical basis be developed that validates the current Product Composition Control System (PCCS) models for use during the processing of the SWPF-based coupled flowsheet or that leads to the refinements of or modifications to the models that are needed so that the models may be used during the processing of the SWPF-based coupled flowsheet. To support this objective, Savannah River National Laboratory (SRNL) has completed three key interim activities prior to validation of the current or development of refined PCCS models over the anticipated glass composition region for SWPF processing. These three key activities include: (1) defining the glass compositional region over which SWPF is anticipated to be processed, (2) comparing the current PCCS model validation ranges to the SWPF glass compositional region from which compositional gaps can be identified, and (3) developing a test matrix to cover the compositional gaps.
Recommendations for DSD model calculations
International Nuclear Information System (INIS)
Cvelbar, F.
1999-01-01
The latest achievements of the DSD (direct-semidirect) capture model, such as the extension to unbound final states or to densely distributed bound states, and the introduction of the consistent DSD model are reviewed. Recommendations for the future use of the model are presented. (author)
Transition Models for Engineering Calculations
Fraser, C. J.
2007-01-01
While future theoretical and conceptual developments may promote a better understanding of the physical processes involved in the latter stages of boundary layer transition, the designers of rotodynamic machinery and other fluid dynamic devices need effective transition models now. This presentation will therefore center around the development of of some transition models which have been developed as design aids to improve the prediction codes used in the performance evaluation of gas turbine blading. All models are based on Narasimba's concentrated breakdown and spot growth.
Temperature Calculations in the Coastal Modeling System
2017-04-01
ERDC/CHL CHETN-IV-110 April 2017 Approved for public release; distribution is unlimited . Temperature Calculations in the Coastal Modeling...tide) and river discharge at model boundaries, wave radiation stress, and wind forcing over a model computational domain. Physical processes calculated...calculated in the CMS using the following meteorological parameters: solar radiation, cloud cover, air temperature, wind speed, and surface water temperature
Processing flowsheet for the accelerator transmutation of waste (ATW) program
International Nuclear Information System (INIS)
Dewey, H.; Walker, R.; Yarbro, S.
1992-01-01
At Los Alamos, an innovative approach to transmuting long-lived radioactive waste is under investigation. The concept is to use a linear proton accelerator coupled to a solid target to produce an intense neutron flux. The intense stream of neutrons can then be used to fission or transmute long-lived radionuclides to either stable or shorter-lived isotopes. For the program to be successful, robust chemical separations with high efficiencies (>10 5 ) are required. The actual mission, either defense or commercial, will determine what suite of unit operations will be needed. If the mission is to process commercial spent fuel, there are several options available for feed preparation and blanket processing. The baseline option would be an improved PUREX system with the main alternative being the current ATW actinide blanket processing flowsheet. 99 Tc and 129 I are more likely to reach the biosphere than the actinides. Many models have been developed for predicting how the radionuclides will behave in a repository over long time periods. The general conclusion is that the actinides will be sorbed by the soil. Therefore, over a long time period, e.g., a million years their hazard will be lessened because of radioactive decay and dispersion. However, some of the long-lived fission products are not sorbed and could potentially reach the environment over a few thousand year period. Hence, they could present a significant safety hazard. Because of limited resources, most of the priority has been focused on the actinide and technetium blanket assemblies
Nitric-glycolic flowsheet testing for maximum hydrogen generation rate
Energy Technology Data Exchange (ETDEWEB)
Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-03-01
The Defense Waste Processing Facility (DWPF) at the Savannah River Site is developing for implementation a flowsheet with a new reductant to replace formic acid. Glycolic acid has been tested over the past several years and found to effectively replace the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the chemical generation of hydrogen and ammonia, allows purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective adjustment of the SRAT/SME rheology, and is favorable with respect to melter flammability. The objective of this work was to perform DWPF Chemical Process Cell (CPC) testing at conditions that would bound the catalytic hydrogen production for the nitric-glycolic flowsheet.
Calculation models for a nuclear reactor
International Nuclear Information System (INIS)
Tashanii, Ahmed Ali
2010-01-01
Determination of different parameters of nuclear reactors requires neutron transport calculations. Due to complicity of geometry and material composition of the reactor core, neutron calculations were performed for simplified models of the real arrangement. In frame of the present work two models were used for calculations. First, an elementary cell model was used to prepare cross section data set for a homogenized-core reactor model. The homogenized-core reactor model was then used to perform neutron transport calculation. The nuclear reactor is a tank-shaped thermal reactor. The semi-cylindrical core arrangement consists of aluminum made fuel bundles immersed in water which acts as a moderator as well as a coolant. Each fuel bundle consists of aluminum cladded fuel rods arranged in square lattices. (author)
Precipitates/Salts Model Sensitivity Calculation
International Nuclear Information System (INIS)
Mariner, P.
2001-01-01
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation on potential seepage waters within a potential repository drift. This work is developed and documented using procedure AP-3.12Q, ''Calculations'', in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The specific objective of this calculation is to examine the sensitivity and uncertainties of the Precipitates/Salts model. The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b). The calculation in the current document examines the effects of starting water composition, mineral suppressions, and the fugacity of carbon dioxide (CO 2 ) on the chemical evolution of water in the drift
Model cross section calculations using LAHET
International Nuclear Information System (INIS)
Prael, R.E.
1992-01-01
The current status of LAHET is discussed. The effect of a multistage preequilibrium exciton model following the INC is examined for neutron emission benchmark calculations, as is the use of a Fermi breakup model for light nuclei rather than an evaporation model. Comparisons are made also for recent fission cross section experiments, and a discussion of helium production cross sections is presented
Hybrid reduced order modeling for assembly calculations
International Nuclear Information System (INIS)
Bang, Youngsuk; Abdel-Khalik, Hany S.; Jessee, Matthew A.; Mertyurek, Ugur
2015-01-01
Highlights: • Reducing computational cost in engineering calculations. • Reduced order modeling algorithm for multi-physics problem like assembly calculation. • Non-intrusive algorithm with random sampling. • Pattern recognition in the components with high sensitive and large variation. - Abstract: While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system.
Hybrid reduced order modeling for assembly calculations
Energy Technology Data Exchange (ETDEWEB)
Bang, Youngsuk, E-mail: ysbang00@fnctech.com [FNC Technology, Co. Ltd., Yongin-si (Korea, Republic of); Abdel-Khalik, Hany S., E-mail: abdelkhalik@purdue.edu [Purdue University, West Lafayette, IN (United States); Jessee, Matthew A., E-mail: jesseema@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Mertyurek, Ugur, E-mail: mertyurek@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN (United States)
2015-12-15
Highlights: • Reducing computational cost in engineering calculations. • Reduced order modeling algorithm for multi-physics problem like assembly calculation. • Non-intrusive algorithm with random sampling. • Pattern recognition in the components with high sensitive and large variation. - Abstract: While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system.
A Novel Hybrid Similarity Calculation Model
Directory of Open Access Journals (Sweden)
Xiaoping Fan
2017-01-01
Full Text Available This paper addresses the problems of similarity calculation in the traditional recommendation algorithms of nearest neighbor collaborative filtering, especially the failure in describing dynamic user preference. Proceeding from the perspective of solving the problem of user interest drift, a new hybrid similarity calculation model is proposed in this paper. This model consists of two parts, on the one hand the model uses the function fitting to describe users’ rating behaviors and their rating preferences, and on the other hand it employs the Random Forest algorithm to take user attribute features into account. Furthermore, the paper combines the two parts to build a new hybrid similarity calculation model for user recommendation. Experimental results show that, for data sets of different size, the model’s prediction precision is higher than the traditional recommendation algorithms.
A revised calculational model for fission
Energy Technology Data Exchange (ETDEWEB)
Atchison, F
1998-09-01
A semi-empirical parametrization has been developed to calculate the fission contribution to evaporative de-excitation of nuclei with a very wide range of charge, mass and excitation-energy and also the nuclear states of the scission products. The calculational model reproduces measured values (cross-sections, mass distributions, etc.) for a wide range of fissioning systems: Nuclei from Ta to Cf, interactions involving nucleons up to medium energy and light ions. (author)
Precipitates/Salts Model Sensitivity Calculation
Energy Technology Data Exchange (ETDEWEB)
P. Mariner
2001-12-20
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation on potential seepage waters within a potential repository drift. This work is developed and documented using procedure AP-3.12Q, ''Calculations'', in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The specific objective of this calculation is to examine the sensitivity and uncertainties of the Precipitates/Salts model. The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b). The calculation in the current document examines the effects of starting water composition, mineral suppressions, and the fugacity of carbon dioxide (CO{sub 2}) on the chemical evolution of water in the drift.
EARTHWORK VOLUME CALCULATION FROM DIGITAL TERRAIN MODELS
Directory of Open Access Journals (Sweden)
JANIĆ Milorad
2015-06-01
Full Text Available Accurate calculation of cut and fill volume has an essential importance in many fields. This article shows a new method, which has no approximation, based on Digital Terrain Models. A relatively new mathematical model is developed for that purpose, which is implemented in the software solution. Both of them has been tested and verified in the praxis on several large opencast mines. This application is developed in AutoLISP programming language and works in AutoCAD environment.
Plutonium--uranium partitioning; alternate flowsheet Plutonium Reclamation Facility. [SEPHIS
Energy Technology Data Exchange (ETDEWEB)
Fort, L.A.
1975-12-01
The SEPHIS computer program was used to predict the transient and steady-state concentrations in a stage-wise scheme for the Pu reclamation solvent extraction system. With the aid of the computer an alternative flowsheet for Pu--U partitioning was constructed. The goal of the alternative program is to reduce Pu losses from the initial stripping column and reduce the quantity of Pu-bearing wastes from the solvent extraction system. (JSR)
Dissolution flowsheet for high flux isotope reactor fuel
Energy Technology Data Exchange (ETDEWEB)
Foster, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-09-27
As part of the Spent Nuclear Fuel (SNF) processing campaign, H-Canyon is planning to begin dissolving High Flux Isotope Reactor (HFIR) fuel in late FY17 or early FY18. Each HFIR fuel core contains inner and outer fuel elements which were fabricated from uranium oxide (U_{3}O_{8}) dispersed in a continuous Al phase using traditional powder metallurgy techniques. Fuels fabricated in this manner, like other SNF’s processed in H-Canyon, dissolve by the same general mechanisms with similar gas generation rates and the production of H_{2}. The HFIR fuel cores will be dissolved and the recovered U will be down-blended into low-enriched U. HFIR fuel was previously processed in H-Canyon using a unique insert in both the 6.1D and 6.4D dissolvers. Multiple cores will be charged to the same dissolver solution maximizing the concentration of dissolved Al. The objective of this study was to identify flowsheet conditions through literature review and laboratory experimentation to safely and efficiently dissolve the HFIR fuel in H-Canyon. Laboratory-scale experiments were performed to evaluate the dissolution of HFIR fuel using both Al 1100 and Al 6061 T6 alloy coupons. The Al 1100 alloy was considered a representative surrogate which provided an upper bound on the generation of flammable (i.e., H_{2}) gas during the dissolution process. The dissolution of the Al 6061 T6 alloy proceeded at a slower rate than the Al 1100 alloy and was used to verify that the target Al concentration in solution could be achieved for the selected Hg concentration. Mass spectrometry and Raman spectroscopy were used to provide continuous monitoring of the concentration of H_{2} and other permanent gases in the dissolution offgas allowing the development of H_{2} generation rate profiles. The H_{2} generation rates were subsequently used to evaluate if a full HFIR core could be dissolved in an H-Canyon dissolver without exceeding 60% of the
International Nuclear Information System (INIS)
Cardona Alzate, C.A.; Sanchez Toro, O.J.
2006-01-01
Fuel ethanol is considered one of the most important renewable fuels due to the economic and environmental benefits of its use. Lignocellulosic biomass is the most promising feedstock for producing bioethanol due to its global availability and to the energy gain that can be obtained when non-fermentable materials from biomass are used for cogeneration of heat and power. In this work, several process configurations for fuel ethanol production from lignocellulosic biomass were studied through process simulation using Aspen Plus. Some flowsheets considering the possibilities of reaction-reaction integration were taken into account among the studied process routes. The flowsheet variants were analyzed from the energy point of view utilizing as comparison criterion the energy consumption needed to produce 1 L of anhydrous ethanol. Simultaneous saccharification and cofermentation process with water recycling showed the best results accounting an energy consumption of 41.96 MJ/L EtOH. If pervaporation is used as dehydration method instead of azeotropic distillation, further energy savings can be obtained. In addition, energy balance was estimated using the results from the simulation and literature data. A net energy value of 17.65-18.93 MJ/L EtOH was calculated indicating the energy efficiency of the lignocellulosic ethanol
Energy Technology Data Exchange (ETDEWEB)
Cardona Alzate, C.A. [Department of Chemical Engineering, National University of Colombia at Manizales, Cra. 27 No. 64-60, Manizales (Colombia)]. E-mail: ccardonaal@unal.edu.co; Sanchez Toro, O.J. [Department of Chemical Engineering, National University of Colombia at Manizales, Cra. 27 No. 64-60, Manizales (Colombia); Department of Engineering, University of Caldas, Calle 65 No. 26-10, Manizales (Colombia)
2006-10-15
Fuel ethanol is considered one of the most important renewable fuels due to the economic and environmental benefits of its use. Lignocellulosic biomass is the most promising feedstock for producing bioethanol due to its global availability and to the energy gain that can be obtained when non-fermentable materials from biomass are used for cogeneration of heat and power. In this work, several process configurations for fuel ethanol production from lignocellulosic biomass were studied through process simulation using Aspen Plus. Some flowsheets considering the possibilities of reaction-reaction integration were taken into account among the studied process routes. The flowsheet variants were analyzed from the energy point of view utilizing as comparison criterion the energy consumption needed to produce 1 L of anhydrous ethanol. Simultaneous saccharification and cofermentation process with water recycling showed the best results accounting an energy consumption of 41.96 MJ/L EtOH. If pervaporation is used as dehydration method instead of azeotropic distillation, further energy savings can be obtained. In addition, energy balance was estimated using the results from the simulation and literature data. A net energy value of 17.65-18.93 MJ/L EtOH was calculated indicating the energy efficiency of the lignocellulosic ethanol.
Hybrid reduced order modeling for assembly calculations
Energy Technology Data Exchange (ETDEWEB)
Bang, Y.; Abdel-Khalik, H. S. [North Carolina State University, Raleigh, NC (United States); Jessee, M. A.; Mertyurek, U. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)
2013-07-01
While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system. (authors)
Model and calculations for net infiltration
International Nuclear Information System (INIS)
Childs, S.W.; Long, A.
1992-01-01
In this paper a conceptual model for calculating net infiltration is developed and implemented. It incorporates the following important factors: viability of climate for the next 10,000 years, areal viability of net infiltration, and important soil/plant factors that affect the soil water budget of desert soils. Model results are expressed in terms of occurrence probabilities for time periods. In addition the variability of net infiltration is demonstrated both for change with time and differences among three soil/hydrologic units present at the site modeled
Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet
International Nuclear Information System (INIS)
Jain, V.; Shah, H.; Wilmarth, W. R.
2016-01-01
Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated
Reactor Thermal Hydraulic Numerical Calculation And Modeling
International Nuclear Information System (INIS)
Duong Ngoc Hai; Dang The Ba
2008-01-01
In the paper the results of analysis of thermal hydraulic state models using the numerical codes such as COOLOD, EUREKA and RELAP5 for simulation of the reactor thermal hydraulic states are presented. The calculations, analyses of reactor thermal hydraulic state and safety were implemented using different codes. The received numerical results, which were compared each to other, to experiment measurement of Dalat (Vietnam) research reactor and published results, show their appropriateness and capacity for analyses of different appropriate cases. (author)
Nitric-glycolic flowsheet evaluation with the slurry-fed melt rate furnace
Energy Technology Data Exchange (ETDEWEB)
Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Miller, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fowley, M. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Zamecnik, J. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-03-01
The Savannah River National Laboratory (SRNL) was tasked to support validation of the Defense Waste Processing Facility (DWPF) melter offgas flammability model for the nitric-glycolic (NG) flowsheet. The work supports Deliverable 4 of the DWPF & Saltstone Facility Engineering Technical Task Request (TTR)1 and is supplemental to the Cold Cap Evaluation Furnace (CEF) testing conducted in 2014.2 The Slurry-fed Melt Rate Furnace (SMRF) was selected for the supplemental testing as it requires significantly less resources than the CEF and could provide a tool for more rapid analysis of melter feeds in the future. The SMRF platform has been used previously to evaluate melt rate behavior of DWPF glasses, but was modified to accommodate analysis of the offgas stream. Additionally, the Melt Rate Furnace (MRF) and Quartz Melt Rate Furnace (QMRF) were utilized for evaluations. MRF data was used exclusively for melt behavior observations and REDuction/OXidation (REDOX) prediction comparisons and will be briefly discussed in conjunction with its support of the SMRF testing. The QMRF was operated similarly to the SMRF for the same TTR task, but will be discussed in a separate future report. The overall objectives of the SMRF testing were to; 1) Evaluate the efficacy of the SMRF as a platform for steady state melter testing with continuous feeding and offgas analysis; and 2) Generate supplemental melter offgas flammability data to support the melter offgas flammability modelling effort for DWPF implementation of the NG flowsheet.
An Improved Plutonium Trifluoride Precipitation Flowsheet
Energy Technology Data Exchange (ETDEWEB)
Harmon, H.D.
2001-06-26
This report discusses results of the plutonium trifluoride two-stage precipitation study. A series of precipitation experiments was used to identify the significant process variables affecting precipitation performance. A mathematical model of the precipitation process was developed which is based on the formation of plutonium fluoride complexes. The precipitation model relates all process variables, in a single equation, to a single parameter which can be used to control the performance of the plutonium trifluoride precipitation process. Recommendations have been made which will optimize the FB-Line plutonium trifluoride precipitation process.
An Improved Plutonium Trifluoride Precipitation Flowsheet
International Nuclear Information System (INIS)
Harmon, H.D.
2001-01-01
This report discusses results of the plutonium trifluoride two-stage precipitation study. A series of precipitation experiments was used to identify the significant process variables affecting precipitation performance. A mathematical model of the precipitation process was developed which is based on the formation of plutonium fluoride complexes. The precipitation model relates all process variables, in a single equation, to a single parameter which can be used to control the performance of the plutonium trifluoride precipitation process. Recommendations have been made which will optimize the FB-Line plutonium trifluoride precipitation process
Technology development in support of the TWRS process flowsheet. Revision 1
International Nuclear Information System (INIS)
Washenfelder, D.J.
1995-01-01
The Tank Waste Remediation System is to treat and dispose of Hanford's Single-Shell and Double-Shell Tank Waste. The TWRS Process Flowsheet, (WHC-SD-WM-TI-613 Rev. 1) described a flowsheet based on a large number of assumptions and engineering judgements that require verification or further definition through process and technology development activities. This document takes off from the TWRS Process Flowsheet to identify and prioritize tasks that should be completed to strengthen the technical foundation for the flowsheet
Matrix model calculations beyond the spherical limit
International Nuclear Information System (INIS)
Ambjoern, J.; Chekhov, L.; Kristjansen, C.F.; Makeenko, Yu.
1993-01-01
We propose an improved iterative scheme for calculating higher genus contributions to the multi-loop (or multi-point) correlators and the partition function of the hermitian one matrix model. We present explicit results up to genus two. We develop a version which gives directly the result in the double scaling limit and present explicit results up to genus four. Using the latter version we prove that the hermitian and the complex matrix model are equivalent in the double scaling limit and that in this limit they are both equivalent to the Kontsevich model. We discuss how our results away from the double scaling limit are related to the structure of moduli space. (orig.)
Development of Dynamic Environmental Effect Calculation Model
International Nuclear Information System (INIS)
Jeong, Chang Joon; Ko, Won Il
2010-01-01
The short-term, long-term decay heat, and radioactivity are considered as main environmental parameters of SF and HLA. In this study, the dynamic calculation models for radioactivity, short-term decay heat, and long-term heat load of the SF are developed and incorporated into the Doneness code. The spent fuel accumulation has become a major issue for sustainable operation of nuclear power plants. If a once-through fuel cycle is selected, the SF will be disposed into the repository. Otherwise, in case of fast reactor or reuse cycle, the SF will be reprocessed and the high level waste will be disposed
Cost Calculation Model for Logistics Service Providers
Directory of Open Access Journals (Sweden)
Zoltán Bokor
2012-11-01
Full Text Available The exact calculation of logistics costs has become a real challenge in logistics and supply chain management. It is essential to gain reliable and accurate costing information to attain efficient resource allocation within the logistics service provider companies. Traditional costing approaches, however, may not be sufficient to reach this aim in case of complex and heterogeneous logistics service structures. So this paper intends to explore the ways of improving the cost calculation regimes of logistics service providers and show how to adopt the multi-level full cost allocation technique in logistics practice. After determining the methodological framework, a sample cost calculation scheme is developed and tested by using estimated input data. Based on the theoretical findings and the experiences of the pilot project it can be concluded that the improved costing model contributes to making logistics costing more accurate and transparent. Moreover, the relations between costs and performances also become more visible, which enhances the effectiveness of logistics planning and controlling significantly
Flowsheets and source terms for radioactive waste projections
International Nuclear Information System (INIS)
Forsberg, C.W.
1985-03-01
Flowsheets and source terms used to generate radioactive waste projections in the Integrated Data Base (IDB) Program are given. Volumes of each waste type generated per unit product throughput have been determined for the following facilities: uranium mining, UF 6 conversion, uranium enrichment, fuel fabrication, boiling-water reactors (BWRs), pressurized-water reactors (PWRs), and fuel reprocessing. Source terms for DOE/defense wastes have been developed. Expected wastes from typical decommissioning operations for each facility type have been determined. All wastes are also characterized by isotopic composition at time of generation and by general chemical composition. 70 references, 21 figures, 53 tables
Effective hamiltonian calculations using incomplete model spaces
International Nuclear Information System (INIS)
Koch, S.; Mukherjee, D.
1987-01-01
It appears that the danger of encountering ''intruder states'' is substantially reduced if an effective hamiltonian formalism is developed for incomplete model spaces (IMS). In a Fock-space approach, the proof a ''connected diagram theorem'' is fairly straightforward with exponential-type of ansatze for the wave-operator W, provided the normalization chosen for W is separable. Operationally, one just needs a suitable categorization of the Fock-space operators into ''diagonal'' and ''non-diagonal'' parts that is generalization of the corresponding procedure for the complete model space. The formalism is applied to prototypical 2-electron systems. The calculations have been performed on the Cyber 205 super-computer. The authors paid special attention to an efficient vectorization for the construction and solution of the resulting coupled non-linear equations
Model for fission-product calculations
International Nuclear Information System (INIS)
Smith, A.B.
1984-01-01
Many fission-product cross sections remain unmeasurable thus considerable reliance must be placed upon calculational interpolation and extrapolation from the few available measured cross sections. The vehicle, particularly for the lighter fission products, is the conventional optical-statistical model. The applied goals generally are: capture cross sections to 7 to 10% accuracies and inelastic-scattering cross sections to 25 to 50%. Comparisons of recent evaluations and experimental results indicate that these goals too often are far from being met, particularly in the area of inelastic scattering, and some of the evaluated fission-product cross sections are simply physically unreasonable. It is difficult to avoid the conclusion that the models employed in many of the evaluations are inappropriate and/or inappropriately used. In order to alleviate the above unfortunate situations, a regional optical-statistical (OM) model was sought with the goal of quantitative prediction of the cross sections of the lighter-mass (Z = 30-51) fission products. The first step toward that goal was the establishment of a reliable experimental data base consisting of energy-averaged neutron total and differential-scattering cross sections. The second step was the deduction of a regional model from the experimental data. It was assumed that a spherical OM is appropriate: a reasonable and practical assumption. The resulting OM then was verified against the measured data base. Finally, the physical character of the regional model is examined
International Nuclear Information System (INIS)
Seymour, R.G.
1995-01-01
High-level waste (HLW) feed preparation flowsheet development was initiated in fiscal year (FY) 1994 to evaluate alternative flowsheets for preparing melter feed for high-temperature melter (HTM) vitrification testing. Three flowsheets were proposed that might lead to increased processing capacity relative to the Hanford Waste Vitrification Plant (HWVP) and that were flexible enough to use with other HLW melter technologies. This document describes the decision path that led to the selection of flowsheets to be tested in the FY 1994 small-scale HTM tests. Feed preparation flowsheet development for the HLW HTM was based on the feed preparation flowsheet that was developed for the HWVP. This approach allowed the HLW program to build upon the extensive feed preparation flowsheet database developed under the HWVP Project. Primary adjustments to the HWVP flowsheet were to the acid adjustment and glass component additions. Developmental background regarding the individual features of the HLW feed preparation flowsheets is provided. Applicability of the HWVP flowsheet features to the new HLW vitrification mission is discussed. The proposed flowsheets were tested at the laboratory-scale at Pacific Northwest Laboratory. Based on the results of this testing and previously established criteria, a reductant-based flowsheet using glycolic acid and a nitric acid-based flowsheet were selected for the FY 1994 small-scale HTM testing
Preliminary evaluation of Am/Cm melter feed preparation process upset recovery flowsheets
International Nuclear Information System (INIS)
Stone, M.E.
2000-01-01
This document summarizes the results from the development of flowsheets to recover from credible processing errors specified in TTR 99-MNSS/SE-006. The proposed flowsheets were developed in laboratory scale equipment and will be utilized with minor modifications for full scale demonstrations in the Am/Cm Pilot Facility
Sludge batch 9 follow-on actual-waste testing for the nitric-glycolic flowsheet
Energy Technology Data Exchange (ETDEWEB)
Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-03-23
An actual-waste Sludge Batch 9 qualification run with the nitric-glycolic flowsheet (SC-18) was performed in FY16. In order to supplement the knowledge base for the nitric-glycolic flowsheet, additional testing was performed on the product slurries, condensates, and intermediate samples from run SC-18.
Acceleration methods and models in Sn calculations
International Nuclear Information System (INIS)
Sbaffoni, M.M.; Abbate, M.J.
1984-01-01
In some neutron transport problems solved by the discrete ordinate method, it is relatively common to observe some particularities as, for example, negative fluxes generation, slow and insecure convergences and solution instabilities. The commonly used models for neutron flux calculation and acceleration methods included in the most used codes were analyzed, in face of their use in problems characterized by a strong upscattering effect. Some special conclusions derived from this analysis are presented as well as a new method to perform the upscattering scaling for solving the before mentioned problems in this kind of cases. This method has been included in the DOT3.5 code (two dimensional discrete ordinates radiation transport code) generating a new version of wider application. (Author) [es
Dissolution Flowsheet for High Flux Isotope Reactor Fuel
Energy Technology Data Exchange (ETDEWEB)
Daniel, W. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Rudisill, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); O' Rourke, P. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Karay, N. S [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-09-27
As part of the Spent Nuclear Fuel (SNF) processing campaign, H-Canyon is planning to begin dissolving High Flux Isotope Reactor (HFIR) fuel in late FY17 or early FY18. Each HFIR fuel core contains inner and outer fuel elements which were fabricated from uranium oxide (U_{3}O_{8}) dispersed in a continuous Al phase using traditional powder metallurgy techniques. Fuels fabricated in this manner, like other SNF’s processed in H-Canyon, dissolve by the same general mechanisms with similar gas generation rates and the production of H_{2}. The HFIR fuel cores will be dissolved and the recovered U will be down-blended into low-enriched U. HFIR fuel was previously processed in H-Canyon using a unique insert in both the 6.1D and 6.4D dissolvers. Multiple cores will be charged to the same dissolver solution maximizing the concentration of dissolved Al. The objective of this study was to identify flowsheet conditions through literature review and laboratory experimentation to safely and efficiently dissolve the HFIR fuel in H-Canyon. Laboratory-scale experiments were performed to evaluate the dissolution of HFIR fuel using both Al 1100 and Al 6061 T6 alloy coupons. The Al 1100 alloy was considered a representative surrogate which provided an upper bound on the generation of flammable (i.e., H_{2}) gas during the dissolution process. The dissolution of the Al 6061 T6 alloy proceeded at a slower rate than the Al 1100 alloy, and was used to verify that the target Al concentration in solution could be achieved for the selected Hg concentration. Mass spectrometry and Raman spectroscopy were used to provide continuous monitoring of the concentration of H_{2} and other permanent gases in the dissolution offgas, allowing the development of H_{2} generation rate profiles. The H_{2} generation rates were subsequently used to evaluate if a full HFIR core could be dissolved in an H-Canyon dissolver without exceeding 60% of the
Energy Technology Data Exchange (ETDEWEB)
Bugrov, K.V.; Korotaev, V.G.; Korchenkin, K.K.; Logunov, M.V.; Ludin, S.A.; Mashkin, A.N.; Melentev, A.B.; Samarina, N.S. [FSUE ' PAMayak' , Lenin st., 35, Ozersk 456780 (Russian Federation)
2016-07-01
In order to improve the extraction flowsheet of RT-1 Plant two versions of plutonium purification unit flowsheet were developed: a flowsheet with stabilization of Pu(IV)-Np(IV) valence pair and Pu, Np co-recovery, and a flowsheet with stabilization of Pu(IV)-Np(V) valence pair and Pu recovery. The task related to stabilization of the valence pair of the target components in the required state was solved with the use of reactants already applied at RT-1 Plant, namely, hydrogen peroxide, hydrazine nitrate and catalyst (Fe). Both flowsheets were adapted for the plant purification facility with minimum modifications of the equipment, and passed the full scale industrial testing. As a result of this work, reduction in volume and salt content of the raffinate was achieved. (authors)
DWPF nitric-glycolic flowsheet chemical process cell chemistry. Part 1
Energy Technology Data Exchange (ETDEWEB)
Zamecnik, J. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-02-01
The conversions of nitrite to nitrate, the destruction of glycolate, and the conversion of glycolate to formate and oxalate were modeled for the Nitric-Glycolic flowsheet using data from Chemical Process Cell (CPC) simulant runs conducted by SRNL from 2011 to 2015. The goal of this work was to develop empirical correlations for these variables versus measureable variables from the chemical process so that these quantities could be predicted a-priori from the sludge composition and measurable processing variables. The need for these predictions arises from the need to predict the REDuction/OXidation (REDOX) state of the glass from the Defense Waste Processing Facility (DWPF) melter. This report summarizes the initial work on these correlations based on the aforementioned data. Further refinement of the models as additional data is collected is recommended.
Hanford Low-Activity Waste Processing: Demonstration of the Off-Gas Recycle Flowsheet - 13443
Energy Technology Data Exchange (ETDEWEB)
Ramsey, William G.; Esparza, Brian P. [Washington River Protection Solutions, LLC, Richland, WA 99532 (United States)
2013-07-01
Vitrification of Hanford Low-Activity Waste (LAW) is nominally the thermal conversion and incorporation of sodium salts and radionuclides into borosilicate glass. One key radionuclide present in LAW is technetium-99. Technetium-99 is a low energy, long-lived beta emitting radionuclide present in the waste feed in concentrations on the order of 1-10 ppm. The long half-life combined with a high solubility in groundwater results in technetium-99 having considerable impact on performance modeling (as potential release to the environment) of both the waste glass and associated secondary waste products. The current Hanford Tank Waste Treatment and Immobilization Plant (WTP) process flowsheet calls for the recycle of vitrification process off-gas condensates to maximize the portion of technetium ultimately immobilized in the waste glass. This is required as technetium acts as a semi-volatile specie, i.e. considerable loss of the radionuclide to the process off-gas stream can occur during the vitrification process. To test the process flowsheet assumptions, a prototypic off-gas system with recycle capability was added to a laboratory melter (on the order of 1/200 scale) and testing performed. Key test goals included determination of the process mass balance for technetium, a non-radioactive surrogate (rhenium), and other soluble species (sulfate, halides, etc.) which are concentrated by recycling off-gas condensates. The studies performed are the initial demonstrations of process recycle for this type of liquid-fed melter system. This paper describes the process recycle system, the waste feeds processed, and experimental results. Comparisons between data gathered using process recycle and previous single pass melter testing as well as mathematical modeling simulations are also provided. (authors)
Impact of scaling on the nitric-glycolic acid flowsheet
Energy Technology Data Exchange (ETDEWEB)
Lambert, D. [Savannah River Site (SRS), Aiken, SC (United States)
2016-02-01
Savannah River Remediation (SRR) is considering using glycolic acid as a replacement for formic acid in Sludge Receipt and Adjustment Tank (SRAT) processing in the Defense Waste Processing Facility (DWPF). Catalytic decomposition of formic acid is responsible for the generation of hydrogen, a potentially flammable gas, during processing. To prevent the formation of a flammable mixture in the offgas, an air purge is used to dilute the hydrogen concentration below the 60% of the Composite Lower Flammability Limit (CLFL). The offgas is continuously monitored for hydrogen using Gas Chromatographs (GCs). Since formic acid is much more volatile and toxic than glycolic acid, a formic acid spill would lead to the release of much larger quantities to the environment. Switching from formic acid to glycolic acid is expected to eliminate the hydrogen flammability hazard leading to lower air purges, thus downgrading of Safety Significant GCs to Process Support GCs, and minimizing the consequence of a glycolic acid tank leak in DWPF. Overall this leads to a reduction in process operation costs and an increase in safety margin. Experiments were completed at three different scales to demonstrate that the nitric-glycolic acid flowsheet scales from the 4-L lab scale to the 22-L bench scale and 220-L engineering scale. Ten process demonstrations of the sludge-only flowsheet for SRAT and Slurry Mix Evaporator (SME) cycles were performed using Sludge Batch 8 (SB8)-Tank 40 simulant. No Actinide Removal Process (ARP) product or strip effluent was added during the runs. Six experiments were completed at the 4-L scale, two experiments were completed at the 22-L scale, and two experiments were completed at the 220-L scale. Experiments completed at the 4-L scale (100 and 110% acid stoichiometry) were repeated at the 22-L and 220-L scale for scale comparisons.
International Nuclear Information System (INIS)
Shekhar Kumar; Koganti, S.B.
2003-07-01
Benchmarking and application of a computer code SIMPSEX for high plutonium FBR flowsheets was reported recently in an earlier report (IGC-234). Improvements and recompilation of the code (Version 4.01, March 2003) required re-validation with the existing benchmarks as well as additional benchmark flowsheets. Improvements in the high Pu region (Pu Aq >30 g/L) resulted in better results in the 75% Pu flowsheet benchmark. Below 30 g/L Pu Aq concentration, results were identical to those from the earlier version (SIMPSEX Version 3, code compiled in 1999). In addition, 13 published flowsheets were taken as additional benchmarks. Eleven of these flowsheets have a wide range of feed concentrations and few of them are β-γ active runs with FBR fuels having a wide distribution of burnup and Pu ratios. A published total partitioning flowsheet using externally generated U(IV) was also simulated using SIMPSEX. SIMPSEX predictions were compared with listed predictions from conventional SEPHIS, PUMA, PUNE and PUBG. SIMPSEX results were found to be comparable and better than the result from above listed codes. In addition, recently reported UREX demo results along with AMUSE simulations are also compared with SIMPSEX predictions. Results of the benchmarking SIMPSEX with these 14 benchmark flowsheets are discussed in this report. (author)
Concurrent algorithms for nuclear shell model calculations
International Nuclear Information System (INIS)
Mackenzie, L.M.; Macleod, A.M.; Berry, D.J.; Whitehead, R.R.
1988-01-01
The calculation of nuclear properties has proved very successful for light nuclei, but is limited by the power of the present generation of computers. Starting with an analysis of current techniques, this paper discusses how these can be modified to map parallelism inherent in the mathematics onto appropriate parallel machines. A prototype dedicated multiprocessor for nuclear structure calculations, designed and constructed by the authors, is described and evaluated. The approach adopted is discussed in the context of a number of generically similar algorithms. (orig.)
Shell model calculations for exotic nuclei
International Nuclear Information System (INIS)
Brown, B.A.; Wildenthal, B.H.
1991-01-01
A review of the shell-model approach to understanding the properties of light exotic nuclei is given. Binding energies including p and p-sd model spaces and sd and sd-pf model spaces; cross-shell excitations around 32 Mg, including weak-coupling aspects and mechanisms for lowering the ntw excitations; beta decay properties of neutron-rich sd model, of p-sd and sd-pf model spaces, of proton-rich sd model space; coulomb break-up cross sections are discussed. (G.P.) 76 refs.; 12 figs
Uncertainty calculation in transport models and forecasts
DEFF Research Database (Denmark)
Manzo, Stefano; Prato, Carlo Giacomo
Transport projects and policy evaluations are often based on transport model output, i.e. traffic flows and derived effects. However, literature has shown that there is often a considerable difference between forecasted and observed traffic flows. This difference causes misallocation of (public...... implemented by using an approach based on stochastic techniques (Monte Carlo simulation and Bootstrap re-sampling) or scenario analysis combined with model sensitivity tests. Two transport models are used as case studies: the Næstved model and the Danish National Transport Model. 3 The first paper...... in a four-stage transport model related to different variable distributions (to be used in a Monte Carlo simulation procedure), assignment procedures and levels of congestion, at both the link and the network level. The analysis used as case study the Næstved model, referring to the Danish town of Næstved2...
Shell model calculations at superdeformed shapes
International Nuclear Information System (INIS)
Nazarewicz, W.; Dobaczewski, J.; Van Isacker, P.
1991-01-01
Spectroscopy of superdeformed nuclear states opens up an exciting possibility to probe new properties of the nuclear mean field. In particular, the unusually deformed atomic nucleus can serve as a microscopic laboratory of quantum-mechanical symmetries of a three dimensional harmonic oscillator. The classifications and coupling schemes characteristic of weakly deformed systems are expected to be modified in the superdeformed world. The ''superdeformed'' symmetries lead to new quantum numbers and new effective interactions that can be employed in microscopic calculations. New classification schemes can be directly related to certain geometrical properties of the nuclear shape. 63 refs., 7 figs
Shafiee, Alireza
2016-06-25
In optimization-based process flowsheet synthesis, optimization methods, including genetic algorithms (GA), are used as advantageous tools to select a high performance flowsheet by ‘screening’ large numbers of possible flowsheets. In this study, we expand the role of GA to include flowsheet generation through proposing a modified Greedysub tour crossover operator. Performance of the proposed crossover operator is compared with four other commonly used operators. The proposed GA optimizationbased process synthesis method is applied to generate the optimum process flowsheet for a multicomponent membrane-based CO2 capture process. Within defined constraints and using the random-point crossover, CO2 purity of 0.827 (equivalent to 0.986 on dry basis) is achieved which results in improvement (3.4%) over the simplest crossover operator applied. In addition, the least variability in the converged flowsheet and CO2 purity is observed for random-point crossover operator, which approximately implies closeness of the solution to the global optimum, and hence the consistency of the algorithm. The proposed crossover operator is found to improve the convergence speed of the algorithm by 77.6%.
Models for Automated Tube Performance Calculations
International Nuclear Information System (INIS)
Brunkhorst, C.
2002-01-01
High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance
Beyond standard model calculations with Sherpa
Energy Technology Data Exchange (ETDEWEB)
Hoeche, Stefan [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Kuttimalai, Silvan [Durham University, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Schumann, Steffen [Universitaet Goettingen, II. Physikalisches Institut, Goettingen (Germany); Siegert, Frank [Institut fuer Kern- und Teilchenphysik, TU Dresden, Dresden (Germany)
2015-03-01
We present a fully automated framework as part of the Sherpa event generator for the computation of tree-level cross sections in Beyond Standard Model scenarios, making use of model information given in the Universal FeynRules Output format. Elementary vertices are implemented into C++ code automatically and provided to the matrix-element generator Comix at runtime. Widths and branching ratios for unstable particles are computed from the same building blocks. The corresponding decays are simulated with spin correlations. Parton showers, QED radiation and hadronization are added by Sherpa, providing a full simulation of arbitrary BSM processes at the hadron level. (orig.)
International Nuclear Information System (INIS)
Yan Guanghua; Liu, Chihray; Lu Bo; Palta, Jatinder R; Li, Jonathan G
2008-01-01
The purpose of this study was to choose an appropriate head scatter source model for the fast and accurate independent planar dose calculation for intensity-modulated radiation therapy (IMRT) with MLC. The performance of three different head scatter source models regarding their ability to model head scatter and facilitate planar dose calculation was evaluated. A three-source model, a two-source model and a single-source model were compared in this study. In the planar dose calculation algorithm, in-air fluence distribution was derived from each of the head scatter source models while considering the combination of Jaw and MLC opening. Fluence perturbations due to tongue-and-groove effect, rounded leaf end and leaf transmission were taken into account explicitly. The dose distribution was calculated by convolving the in-air fluence distribution with an experimentally determined pencil-beam kernel. The results were compared with measurements using a diode array and passing rates with 2%/2 mm and 3%/3 mm criteria were reported. It was found that the two-source model achieved the best agreement on head scatter factor calculation. The three-source model and single-source model underestimated head scatter factors for certain symmetric rectangular fields and asymmetric fields, but similar good agreement could be achieved when monitor back scatter effect was incorporated explicitly. All the three source models resulted in comparable average passing rates (>97%) when the 3%/3 mm criterion was selected. The calculation with the single-source model and two-source model was slightly faster than the three-source model due to their simplicity
Energy Technology Data Exchange (ETDEWEB)
Yan Guanghua [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Liu, Chihray; Lu Bo; Palta, Jatinder R; Li, Jonathan G [Department of Radiation Oncology, University of Florida, Gainesville, FL 32610-0385 (United States)
2008-04-21
The purpose of this study was to choose an appropriate head scatter source model for the fast and accurate independent planar dose calculation for intensity-modulated radiation therapy (IMRT) with MLC. The performance of three different head scatter source models regarding their ability to model head scatter and facilitate planar dose calculation was evaluated. A three-source model, a two-source model and a single-source model were compared in this study. In the planar dose calculation algorithm, in-air fluence distribution was derived from each of the head scatter source models while considering the combination of Jaw and MLC opening. Fluence perturbations due to tongue-and-groove effect, rounded leaf end and leaf transmission were taken into account explicitly. The dose distribution was calculated by convolving the in-air fluence distribution with an experimentally determined pencil-beam kernel. The results were compared with measurements using a diode array and passing rates with 2%/2 mm and 3%/3 mm criteria were reported. It was found that the two-source model achieved the best agreement on head scatter factor calculation. The three-source model and single-source model underestimated head scatter factors for certain symmetric rectangular fields and asymmetric fields, but similar good agreement could be achieved when monitor back scatter effect was incorporated explicitly. All the three source models resulted in comparable average passing rates (>97%) when the 3%/3 mm criterion was selected. The calculation with the single-source model and two-source model was slightly faster than the three-source model due to their simplicity.
Model calculations for electrochemically etched neutron detectors
International Nuclear Information System (INIS)
Pitt, E.; Scharmann, A.; Werner, B.
1988-01-01
Electrochemical etching has been established as a common method for visualisation of nuclear tracks in solid state nuclear track detectors. Usually the Mason equation, which describes the amplification of the electrical field strength at the track tip, is used to explain the treeing effect of electrochemical etching. The yield of neutron-induced tracks from electrochemically etched CR-39 track detectors was investigated with respect to the electrical parameters. A linear dependence on the response from the macroscopic field strength was measured which could not be explained by the Mason equation. It was found that the reality of a recoil proton track in the detector does not fit the boundary conditions which are necessary when the Mason equation is used. An alternative model was introduced to describe the track and detector geometry in the case of a neutron track detector. The field strength at the track tip was estimated with this model and compared with the experimental data, yielding good agreement. (author)
Model calculation of thermal conductivity in antiferromagnets
Energy Technology Data Exchange (ETDEWEB)
Mikhail, I.F.I., E-mail: ifi_mikhail@hotmail.com; Ismail, I.M.M.; Ameen, M.
2015-11-01
A theoretical study is given of thermal conductivity in antiferromagnetic materials. The study has the advantage that the three-phonon interactions as well as the magnon phonon interactions have been represented by model operators that preserve the important properties of the exact collision operators. A new expression for thermal conductivity has been derived that involves the same terms obtained in our previous work in addition to two new terms. These two terms represent the conservation and quasi-conservation of wavevector that occur in the three-phonon Normal and Umklapp processes respectively. They gave appreciable contributions to the thermal conductivity and have led to an excellent quantitative agreement with the experimental measurements of the antiferromagnet FeCl{sub 2}. - Highlights: • The Boltzmann equations of phonons and magnons in antiferromagnets have been studied. • Model operators have been used to represent the magnon–phonon and three-phonon interactions. • The models possess the same important properties as the exact operators. • A new expression for the thermal conductivity has been derived. • The results showed a good quantitative agreement with the experimental data of FeCl{sub 2}.
An analysis of alternative New Technical Strategy flowsheets for tank waste remediation system
International Nuclear Information System (INIS)
Booker, C.P.
1994-01-01
The Hanford Tank remediation plans have gone through a few revisions for the best waste processing system. Some designs have been complex while others have been fairly simple. One of the key means in understanding and selecting among the various proposed systems is a discrete events modeling of the system. This modeling provides insight into (1) The total required size of the system; (2) The amount of material, such as reagents and other added materials that must be supplied; (3) The final mass of waste that must be stored; and (4) Areas within the system where a small change can greatly effect the total system. Discrete events modeling also provides the means by which various proposed systems may be compared. It is the framework in which variations within a particular system may be explored and compared to other instantiations. This study examines the current New Technical Strategy flowsheet system with discrete event modeling. Some of the possible variations within that system are examined and compared. Further, an previously proposed, more complex system is examined
International Nuclear Information System (INIS)
Bell, J.T.; Burch, W.D.; Collins, E.D.; Forsberg, C.W.; Prince, B.E.; Bond, W.D.; Campbell, D.O.; Delene, J.G.; Mailen, J.C.
1990-08-01
A preliminary study by a group of experts at ORNL has generated and evaluated a number of aqueous and non-aqueous flowsheets for recovering transuranium actinides from LWR fuel for use as fuel in an LMR and, at the same time, for transmutation of the wastes to less hazardous materials. The need for proliferation resistance was a consideration in the flowsheets. The current state of development of the flowsheets was evaluated and recommendations for additional study were made. 3 refs., 6 figs
Standard Model theory calculations and experimental tests
International Nuclear Information System (INIS)
Cacciari, M.; Hamel de Monchenault, G.
2015-01-01
To present knowledge, all the physics at the Large Hadron Collider (LHC) can be described in the framework of the Standard Model (SM) of particle physics. Indeed the newly discovered Higgs boson with a mass close to 125 GeV seems to confirm the predictions of the SM. Thus, besides looking for direct manifestations of the physics beyond the SM, one of the primary missions of the LHC is to perform ever more stringent tests of the SM. This requires not only improved theoretical developments to produce testable predictions and provide experiments with reliable event generators, but also sophisticated analyses techniques to overcome the formidable experimental environment of the LHC and perform precision measurements. In the first section, we describe the state of the art of the theoretical tools and event generators that are used to provide predictions for the production cross sections of the processes of interest. In section 2, inclusive cross section measurements with jets, leptons and vector bosons are presented. Examples of differential cross sections, charge asymmetries and the study of lepton pairs are proposed in section 3. Finally, in section 4, we report studies on the multiple production of gauge bosons and constraints on anomalous gauge couplings
Chemical flowsheet conditions for preparing urania spheres by internal gelation
International Nuclear Information System (INIS)
Haas, P.A.; Begovich, J.M.; Ryon, A.D.; Vavruska, J.S.
1979-01-01
Small, ceramic urania spheres can be prepared for use as nuclear fuel by internal chemical gelation of uranyl nitrate solution droplets. Decomposition of hexamethylenetetramine (HMTA) dissolved in the uranyl nitrate solution releases ammonia to precipitate hydrated UO 3 . Previously established flowsheet conditions have been improved and modified at ORNL and have been applied to prepare dense UO 2 spheres with average diameters of 1200, 300, and 30 μm. Acid-deficient uranyl nitrate (ADUN) solutions up to 3.4 M in uranium with NO 3 - /U mole ratios of 1.5 to 1.7 are prepared by dissolution of U 3 O 8 or UO 3 . Continuous mixing of metered, cooled ADUN containing urea and HMTA solutions provides a smooth, regulated flow of the temperature-sensitive feed solution. The gelation times for solution drops in organic liquids at 45 to 95 0 C depend on both the chemical reaction rates and the rates of heat transfer. The gel properties vary with temperature and other gelation variables. Gelation conditions were determined which allow easy washing, drying, firing, and sintering to produce dense UO 2 spheres of all three sizes. The 1200- and 300-μm UO 2 spheres were pepared by gelation in trichloroethylene at 50 to 65 0 C; 2-ethyl-l-hexanol was used as the gelation medium to prepare 30-μm UO 2 spheres. Washing and drying requirements were determined. The gel dried to 225 0 C contains about 95% UO 3 ; the remaining components are H 2 O, NH 3 - , which are volatilized during firing to UO 2
International Nuclear Information System (INIS)
Penwell, D.L.
1994-01-01
This preliminary flowsheet document describes an ion exchange process which uses resorcinol-formaldehyde (R-F) resin to remove cesium from Hanford tank waste. The flowsheet describes one possible equipment configuration, and contains mass balances based on that configuration with feeds of Neutralized Current Acid Waste, and Double Shell Slurry Feed. The flowsheet also discusses process alternatives, unresolved issues, and development needs associated with the ion exchange process. It is expected that this flowsheet will evolve as open issues are resolved and progress is made on development needs. This is part of the Tank Waste Remediation Program at Hanford. 26 refs, 6 figs, 25 tabs
Defense Waste Processing Facility Nitric- Glycolic Flowsheet Chemical Process Cell Chemistry: Part 2
Energy Technology Data Exchange (ETDEWEB)
Zamecnik, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-06-06
The conversions of nitrite to nitrate, the destruction of glycolate, and the conversion of glycolate to formate and oxalate were modeled for the Nitric-Glycolic flowsheet using data from Chemical Process Cell (CPC) simulant runs conducted by Savannah River National Laboratory (SRNL) from 2011 to 2016. The goal of this work was to develop empirical correlation models to predict these values from measureable variables from the chemical process so that these quantities could be predicted a-priori from the sludge or simulant composition and measurable processing variables. The need for these predictions arises from the need to predict the REDuction/OXidation (REDOX) state of the glass from the Defense Waste Processing Facility (DWPF) melter. This report summarizes the work on these correlations based on the aforementioned data. Previous work on these correlations was documented in a technical report covering data from 2011-2015. This current report supersedes this previous report. Further refinement of the models as additional data are collected is recommended.
Swartjes F; ECO
2003-01-01
Twenty scenarios, differing with respect to land use, soil type and contaminant, formed the basis for calculating human exposure from soil contaminants with the use of models contributed by seven European countries (one model per country). Here, the human exposures to children and children
Precipitates/Salts Model Calculations for Various Drift Temperature Environments
International Nuclear Information System (INIS)
Marnier, P.
2001-01-01
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation within a repository drift. This work is developed and documented using procedure AP-3.12Q, Calculations, in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The primary objective of this calculation is to predict the effects of evaporation on the abstracted water compositions established in ''EBS Incoming Water and Gas Composition Abstraction Calculations for Different Drift Temperature Environments'' (BSC 2001c). A secondary objective is to predict evaporation effects on observed Yucca Mountain waters for subsequent cement interaction calculations (BSC 2001d). The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b)
DIGA/NSL new calculational model in slab geometry
International Nuclear Information System (INIS)
Makai, M.; Gado, J.; Kereszturi, A.
1987-04-01
A new calculational model is presented based on a modified finite-difference algorithm, in which the coefficients are determined by means of the so-called gamma matrices. The DIGA program determines the gamma matrices and the NSL program realizes the modified finite difference model. Both programs assume slab cell geometry, DIGA assumes 2 energy groups and 3 diffusive regions. The DIGA/NSL programs serve to study the new calculational model. (author)
A universal calculation model for the controlled electric transmission line
International Nuclear Information System (INIS)
Zivzivadze, O.; Zivzivadze, L.
2009-01-01
Difficulties associated with the development of calculation models are analyzed, and the ways of resolution of these problems are given. A version of the equivalent circuit as a six-pole network, the parameters of which do not depend on the angle of shift Θ between the voltage vectors of circuits is offered. The interrelation between the parameters of the equivalent circuit and the transmission constants of the line was determined. A universal calculation model for the controlled electric transmission line was elaborated. The model allows calculating the stationary modes of lines of such classes at any angle of shift Θ between the circuits. (author)
FLOWSHEET FOR ALUMINUM REMOVAL FROM SLUDGE BATCH 6
International Nuclear Information System (INIS)
Pike, J.; Gillam, J.
2008-01-01
Samples of Tank 12 sludge slurry show a substantially larger fraction of aluminum than originally identified in sludge batch planning. The Liquid Waste Organization (LWO) plans to formulate Sludge Batch 6 (SB6) with about one half of the sludge slurry in Tank 12 and one half of the sludge slurry in Tank 4. LWO identified aluminum dissolution as a method to mitigate the effect of having about 50% more solids in High Level Waste (HLW) sludge than previously planned. Previous aluminum dissolution performed in a HLW tank in 1982 was performed at approximately 85 C for 5 days and dissolved nearly 80% of the aluminum in the sludge slurry. In 2008, LWO successfully dissolved 64% of the aluminum at approximately 60 C in 46 days with minimal tank modifications and using only slurry pumps as a heat source. This report establishes the technical basis and flowsheet for performing an aluminum removal process in Tank 51 for SB6 that incorporates the lessons learned from previous aluminum dissolution evolutions. For SB6, aluminum dissolution process temperature will be held at a minimum of 65 C for at least 24 days, but as long as practical or until as much as 80% of the aluminum is dissolved. As planned, an aluminum removal process can reduce the aluminum in SB6 from about 84,500 kg to as little as 17,900 kg with a corresponding reduction of total insoluble solids in the batch from 246,000 kg to 131,000 kg. The extent of the reduction may be limited by the time available to maintain Tank 51 at dissolution temperature. The range of dissolution in four weeks based on the known variability in dissolution kinetics can range from 44 to more than 80%. At 44% of the aluminum dissolved, the mass reduction is approximately 1/2 of the mass noted above, i.e., 33,300 kg of aluminum instead of 66,600 kg. Planning to reach 80% of the aluminum dissolved should allow a maximum of 81 days for dissolution and reduce the allowance if test data shows faster kinetics. 47,800 kg of the dissolved
Procafd: Computer Aided Tool for Synthesis-Design & Analysis of Chemical Process Flowsheets
DEFF Research Database (Denmark)
Kumar Tula, Anjan; Eden, Mario R.; Gani, Rafiqul
2015-01-01
and emission to the surrounding and many more. In terms of approaches to solve the synthesis-design problem three major lines of attack have emerged: (a) the knowledge based approach [1] which relies on engineering knowledge & problem insights, (b) the optimization approach [2] which relies on the use...... of mathematical programming techniques, (c) hybrid approach which combine two or more approaches. D’Anterroches [3] proposed a group contribution based hybrid approach to solve the synthesis-design problem where, chemical process flowsheets could be synthesized in the same way as atoms or groups of atoms...... parameters for the operations of the high ranked flowsheets are established through reverse engineering approaches based on driving forces available for each operation. In the final stage, rigorous simulation is performed to validate the synthesis-design. Note that since the flowsheet is synthesized...
ECP evaluation by water radiolysis and ECP model calculations
Energy Technology Data Exchange (ETDEWEB)
Hanawa, S.; Nakamura, T.; Uchida, S. [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan); Kus, P.; Vsolak, R.; Kysela, J. [Nuclear Research Inst. Rez plc, Rez (Czech Republic)
2010-07-01
In-pile ECP measurements data was evaluated by water radiolysis calculations. The data was obtained by using an in-pile loop in an experimental reactor, LVR-15, at the Nuclear Research Institute (NRI) in Czech Republic. Three types of ECP sensors, a Pt electrode, an Ag/AgCl sensor and a zirconia membrane sensor containing Ag/Ag{sub 2}O were used at several levels of the irradiation rig at various neutron flux and gamma rates. For water radiolysis calculation, the in-pile loop was modeled to several nodes following their design specifications, operating conditions such as flow rates, dose rate distributions of neutron and gamma-ray and so on. Concentration of chemical species along the water flow was calculated by a radiolysis code, WRAC-J. The radiolysis calculation results were transferred to an ECP model. In the model, anodic and cathodic current densities were calculated with combination of an electrochemistry model and an oxide film growth model. The measured ECP data were compared with the radiolysis/ECP calculation results, and applicability the of radiolysis model was confirmed. In addition, anomalous phenomenon appears in the in-pile loop was also investigated by radiolysis calculations. (author)
Comparative calculations and validation studies with atmospheric dispersion models
International Nuclear Information System (INIS)
Paesler-Sauer, J.
1986-11-01
This report presents the results of an intercomparison of different mesoscale dispersion models and measured data of tracer experiments. The types of models taking part in the intercomparison are Gaussian-type, numerical Eulerian, and Lagrangian dispersion models. They are suited for the calculation of the atmospherical transport of radionuclides released from a nuclear installation. For the model intercomparison artificial meteorological situations were defined and corresponding arithmetical problems were formulated. For the purpose of model validation real dispersion situations of tracer experiments were used as input data for model calculations; in these cases calculated and measured time-integrated concentrations close to the ground are compared. Finally a valuation of the models concerning their efficiency in solving the problems is carried out by the aid of objective methods. (orig./HP) [de
Model calculations of nuclear data for biologically-important elements
International Nuclear Information System (INIS)
Chadwick, M.B.; Blann, M.; Reffo, G.; Young, P.G.
1994-05-01
We describe calculations of neutron-induced reactions on carbon and oxygen for incident energies up to 70 MeV, the relevant clinical energy in radiation neutron therapy. Our calculations using the FKK-GNASH, GNASH, and ALICE codes are compared with experimental measurements, and their usefulness for modeling reactions on biologically-important elements is assessed
Energy Technology Data Exchange (ETDEWEB)
Lambert, Dan P.; Stone, Michael E.; Newell, J. David; Fellinger, Terri L.; Bricker, Jonathan M.
2012-09-14
The Defense Waste Processing Facility (DWPF) processes legacy nuclear waste generated at the Savannah River Site (SRS) during production of plutonium and tritium demanded by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass canisters is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. Testing was initiated to determine whether the elimination of formic acid from the DWPF's chemical processing flowsheet would eliminate catalytic hydrogen generation. Historically, hydrogen is generated in chemical processing of alkaline High Level Waste sludge in DWPF. In current processing, sludge is combined with nitric and formic acid to neutralize the waste, reduce mercury and manganese, destroy nitrite, and modify (thin) the slurry rheology. The noble metal catalyzed formic acid decomposition produces hydrogen and carbon dioxide. Elimination of formic acid by replacement with glycolic acid has the potential to eliminate the production of catalytic hydrogen. Flowsheet testing was performed to develop the nitric-glycolic acid flowsheet as an alternative to the nitric-formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be reduced and removed by steam stripping in DWPF with no catalytic hydrogen generation. All processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Ten DWPF tests were performed with nonradioactive simulants designed to cover a broad compositional range. No hydrogen was generated in testing without formic acid.
In-Drift Microbial Communities Model Validation Calculations
Energy Technology Data Exchange (ETDEWEB)
D. M. Jolley
2001-09-24
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data.
In-Drift Microbial Communities Model Validation Calculation
Energy Technology Data Exchange (ETDEWEB)
D. M. Jolley
2001-10-31
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data.
IN-DRIFT MICROBIAL COMMUNITIES MODEL VALIDATION CALCULATIONS
Energy Technology Data Exchange (ETDEWEB)
D.M. Jolley
2001-12-18
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN M09909SPAMINGl.003 using its replacement DTN M00106SPAIDMO 1.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 200 1) which includes controls for the management of electronic data.
In-Drift Microbial Communities Model Validation Calculations
International Nuclear Information System (INIS)
Jolley, D.M.
2001-01-01
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS MandO 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS MandO 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS MandO 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS MandO (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data
IN-DRIFT MICROBIAL COMMUNITIES MODEL VALIDATION CALCULATIONS
International Nuclear Information System (INIS)
D.M. Jolley
2001-01-01
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M andO 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M andO 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN M09909SPAMINGl.003 using its replacement DTN M00106SPAIDMO 1.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M andO 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M andO (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 200 1) which includes controls for the management of electronic data
Hualien forced vibration calculation with a finite element model
International Nuclear Information System (INIS)
Wang, F.; Gantenbein, F.; Nedelec, M.; Duretz, Ch.
1995-01-01
The forced vibration tests of the Hualien mock-up were useful to validate finite element models developed for soil-structure interaction. In this paper the two sets of tests with and without backfill were analysed. the methods used are based on finite element modeling for the soil. Two approaches were considered: calculation of soil impedance followed by the calculation of the transfer functions with a model taking into account the superstructure and the impedance; direct calculation of the soil-structure transfer functions, with the soil and the structure being represented in the same model by finite elements. Blind predictions and post-test calculations are presented and compared with the test results. (author). 4 refs., 8 figs., 2 tabs
The accuracy of heavy ion optical model calculations
International Nuclear Information System (INIS)
Kozik, T.
1980-01-01
There is investigated in detail the sources and magnitude of numerical errors in heavy ion optical model calculations. It is shown on example of 20 Ne + 24 Mg scattering at Esub(LAB)=100 MeV. (author)
NLOM - a program for nonlocal optical model calculations
International Nuclear Information System (INIS)
Kim, B.T.; Kyum, M.C.; Hong, S.W.; Park, M.H.; Udagawa, T.
1992-01-01
A FORTRAN program NLOM for nonlocal optical model calculations is described. It is based on a method recently developed by Kim and Udagawa, which utilizes the Lanczos technique for solving integral equations derived from the nonlocal Schroedinger equation. (orig.)
Experimental evaluation of analytical penumbra calculation model for wobbled beams
International Nuclear Information System (INIS)
Kohno, Ryosuke; Kanematsu, Nobuyuki; Yusa, Ken; Kanai, Tatsuaki
2004-01-01
The goal of radiotherapy is not only to apply a high radiation dose to a tumor, but also to avoid side effects in the surrounding healthy tissue. Therefore, it is important for carbon-ion treatment planning to calculate accurately the effects of the lateral penumbra. In this article, for wobbled beams under various irradiation conditions, we focus on the lateral penumbras at several aperture positions of one side leaf of the multileaf collimator. The penumbras predicted by an analytical penumbra calculation model were compared with the measured results. The results calculated by the model for various conditions agreed well with the experimental ones. In conclusion, we found that the analytical penumbra calculation model could predict accurately the measured results for wobbled beams and it was useful for carbon-ion treatment planning to apply the model
A methodology for constructing the calculation model of scientific spreadsheets
Vos, de M.; Wielemaker, J.; Schreiber, G.; Wielinga, B.; Top, J.L.
2015-01-01
Spreadsheets models are frequently used by scientists to analyze research data. These models are typically described in a paper or a report, which serves as single source of information on the underlying research project. As the calculation workflow in these models is not made explicit, readers are
Mathematical models for calculating radiation dose to the fetus
International Nuclear Information System (INIS)
Watson, E.E.
1992-01-01
Estimates of radiation dose from radionuclides inside the body are calculated on the basis of energy deposition in mathematical models representing the organs and tissues of the human body. Complex models may be used with radiation transport codes to calculate the fraction of emitted energy that is absorbed in a target tissue even at a distance from the source. Other models may be simple geometric shapes for which absorbed fractions of energy have already been calculated. Models of Reference Man, the 15-year-old (Reference Woman), the 10-year-old, the five-year-old, the one-year-old, and the newborn have been developed and used for calculating specific absorbed fractions (absorbed fractions of energy per unit mass) for several different photon energies and many different source-target combinations. The Reference woman model is adequate for calculating energy deposition in the uterus during the first few weeks of pregnancy. During the course of pregnancy, the embryo/fetus increases rapidly in size and thus requires several models for calculating absorbed fractions. In addition, the increases in size and changes in shape of the uterus and fetus result in the repositioning of the maternal organs and in different geometric relationships among the organs and the fetus. This is especially true of the excretory organs such as the urinary bladder and the various sections of the gastrointestinal tract. Several models have been developed for calculating absorbed fractions of energy in the fetus, including models of the uterus and fetus for each month of pregnancy and complete models of the pregnant woman at the end of each trimester. In this paper, the available models and the appropriate use of each will be discussed. (Author) 19 refs., 7 figs
Model for calculating the boron concentration in PWR type reactors
International Nuclear Information System (INIS)
Reis Martins Junior, L.L. dos; Vanni, E.A.
1986-01-01
A PWR boron concentration model has been developed for use with RETRAN code. The concentration model calculates the boron mass balance in the primary circuit as the injected boron mixes and is transported through the same circuit. RETRAN control blocks are used to calculate the boron concentration in fluid volumes during steady-state and transient conditions. The boron reactivity worth is obtained from the core concentration and used in RETRAN point kinetics model. A FSAR type analysis of a Steam Line Break Accident in Angra I plant was selected to test the model and the results obtained indicate a sucessfull performance. (Author) [pt
Microbial Communities Model Parameter Calculation for TSPA/SR
International Nuclear Information System (INIS)
D. Jolley
2001-01-01
This calculation has several purposes. First the calculation reduces the information contained in ''Committed Materials in Repository Drifts'' (BSC 2001a) to useable parameters required as input to MING V1.O (CRWMS M and O 1998, CSCI 30018 V1.O) for calculation of the effects of potential in-drift microbial communities as part of the microbial communities model. The calculation is intended to replace the parameters found in Attachment II of the current In-Drift Microbial Communities Model revision (CRWMS M and O 2000c) with the exception of Section 11-5.3. Second, this calculation provides the information necessary to supercede the following DTN: M09909SPAMING1.003 and replace it with a new qualified dataset (see Table 6.2-1). The purpose of this calculation is to create the revised qualified parameter input for MING that will allow ΔG (Gibbs Free Energy) to be corrected for long-term changes to the temperature of the near-field environment. Calculated herein are the quadratic or second order regression relationships that are used in the energy limiting calculations to potential growth of microbial communities in the in-drift geochemical environment. Third, the calculation performs an impact review of a new DTN: M00012MAJIONIS.000 that is intended to replace the currently cited DTN: GS9809083 12322.008 for water chemistry data used in the current ''In-Drift Microbial Communities Model'' revision (CRWMS M and O 2000c). Finally, the calculation updates the material lifetimes reported on Table 32 in section 6.5.2.3 of the ''In-Drift Microbial Communities'' AMR (CRWMS M and O 2000c) based on the inputs reported in BSC (2001a). Changes include adding new specified materials and updating old materials information that has changed
A model to calculate the burn of gadolinium in PWR
International Nuclear Information System (INIS)
Sannazzaro, L.R.
1983-01-01
A cell model to calculate the burnup of a PWR fuel element with gadolinium as a poison, projected by KWU, is presented. With the model proposed, the burn of the gadolinium isotopes is analyzed, as well as the effect of these isotopes in the fuel element behaviour. The results obtained with this cell model are compared with those obtained by a conventional cell model. (E.G.) [pt
batman: BAsic Transit Model cAlculatioN in Python
Kreidberg, Laura
2015-11-01
I introduce batman, a Python package for modeling exoplanet transit light curves. The batman package supports calculation of light curves for any radially symmetric stellar limb darkening law, using a new integration algorithm for models that cannot be quickly calculated analytically. The code uses C extension modules to speed up model calculation and is parallelized with OpenMP. For a typical light curve with 100 data points in transit, batman can calculate one million quadratic limb-darkened models in 30 seconds with a single 1.7 GHz Intel Core i5 processor. The same calculation takes seven minutes using the four-parameter nonlinear limb darkening model (computed to 1 ppm accuracy). Maximum truncation error for integrated models is an input parameter that can be set as low as 0.001 ppm, ensuring that the community is prepared for the precise transit light curves we anticipate measuring with upcoming facilities. The batman package is open source and publicly available at https://github.com/lkreidberg/batman .
Comparison of Calculation Models for Bucket Foundation in Sand
DEFF Research Database (Denmark)
Vaitkunaite, Evelina; Molina, Salvador Devant; Ibsen, Lars Bo
The possibility of fast and rather precise preliminary offshore foundation design is desirable. The ultimate limit state of bucket foundation is investigated using three different geotechnical calculation tools: [Ibsen 2001] an analytical method, LimitState:GEO and Plaxis 3D. The study has focused...... on resultant bearing capacity of variously embedded foundation in sand. The 2D models, [Ibsen 2001] and LimitState:GEO can be used for the preliminary design because they are fast and result in a rather similar bearing capacity calculation compared with the finite element models of Plaxis 3D. The 2D models...
Statistical Model Calculations for (n,γ Reactions
Directory of Open Access Journals (Sweden)
Beard Mary
2015-01-01
Full Text Available Hauser-Feshbach (HF cross sections are of enormous importance for a wide range of applications, from waste transmutation and nuclear technologies, to medical applications, and nuclear astrophysics. It is a well-observed result that diﬀerent nuclear input models sensitively aﬀect HF cross section calculations. Less well known however are the eﬀects on calculations originating from model-specific implementation details (such as level density parameter, matching energy, back-shift and giant dipole parameters, as well as eﬀects from non-model aspects, such as experimental data truncation and transmission function energy binning. To investigate the eﬀects or these various aspects, Maxwellian-averaged neutron capture cross sections have been calculated for approximately 340 nuclei. The relative eﬀects of these model details will be discussed.
Interacting boson model: Microscopic calculations for the mercury isotopes
Energy Technology Data Exchange (ETDEWEB)
Druce, C.H.; Pittel, S.; Barrett, B.R.; Duval, P.D.
1987-05-15
Microscopic calculations of the parameters of the proton--neutron interacting boson model (IBM-2) appropriate to the even Hg isotopes are reported. The calculations are based on the Otsuka--Arima--Iachello boson mapping procedure, which is briefly reviewed. Renormalization of the parameters due to exclusion of the l = 4 g boson is treated perturbatively. The calculations employ a semi-realistic shell-model Hamiltonian with no adjustable parameters. The calculated parameters of the IBM-2 Hamiltonian are used to generate energy spectra and electromagnetic transition probabilities, which are compared with experimental data and with the result of phenomenological fits. The overall agreement is reasonable with some notable exceptions, which are discussed. Particular attention is focused on the parameters of the Majorana interaction and on the F-spin character of low-lying levels. copyright 1987 Academic Press, Inc.
The interacting boson model: Microscopic calculations for the mercury isotopes
Druce, C. H.; Pittel, S.; Barrett, B. R.; Duval, P. D.
1987-05-01
Microscopic calculations of the parameters of the proton-neutron interacting boson model (IBM-2) appropriate to the even Hg isotopes are reported. The calculations are based on the Otsuka-Armia-Iachello boson mapping procedure, which is briefly reviewed. Renormalization of the parameters due to exclusion of the l=4 g boson is treated perturbatively. The calculations employ a semi-realistic shell-model Hamiltonian with no adjustable parameters. The calculated parameters of the IBM-2 Hamiltonian are used to generate energy spectra and electromagnetic transition probabilities, which are compared with experimental data and with the result of phenomenological fits. The overall agreement is reasonable with some notable exceptions, which are discussed. Particular attention is focused on the parameters of the Majorana interaction and on the F-spin character of low-lying levels.
Optimal Height Calculation and Modelling of Noise Barrier
Directory of Open Access Journals (Sweden)
Raimondas Grubliauskas
2011-04-01
Full Text Available Transport is one of the main sources of noise having a particularly strong negative impact on the environment. In the city, one of the best methods to reduce the spread of noise in residential areas is a noise barrier. The article presents noise reduction barrier adaptation with empirical formulas calculating and modelling noise distribution. The simulation of noise dispersion has been performed applying the CadnaA program that allows modelling the noise levels of various developments under changing conditions. Calculation and simulation is obtained by assessing the level of noise reduction using the same variables. The investigation results are presented as noise distribution isolines. The selection of a different height of noise barriers are the results calculated at the heights of 1, 4 and 15 meters. The level of noise reduction at the maximum overlap of data, calculation and simulation has reached about 10%.Article in Lithuanian
Preliminary flowsheet for the conversion of Hanford high-level waste to glass
International Nuclear Information System (INIS)
Beary, M.M.; Chick, L.A.; Ely, P.C.; Gott, S.A.
1977-06-01
The flowsheets describe a process for converting waste removed from the Hanford underground waste tanks to more immobile form. The process involves a chemical separation of the radionuclides from industrial chemicals, and then making glass from the resulting small volume of highly radioactive waste. Removal of Sr, actinides, cesium, and technetium is discussed
Recoil corrected bag model calculations for semileptonic weak decays
International Nuclear Information System (INIS)
Lie-Svendsen, Oe.; Hoegaasen, H.
1987-02-01
Recoil corrections to various model results for strangeness changing weak decay amplitudes have been developed. It is shown that the spurious reference frame dependence of earlier calculations is reduced. The second class currents are generally less important than obtained by calculations in the static approximation. Theoretical results are compared to observations. The agreement is quite good, although the values for the Cabibbo angle obtained by fits to the decay rates are somewhat to large
Optical model calculations with the code ECIS95
Energy Technology Data Exchange (ETDEWEB)
Carlson, B V [Departamento de Fisica, Instituto Tecnologico da Aeronautica, Centro Tecnico Aeroespacial (Brazil)
2001-12-15
The basic features of elastic and inelastic scattering within the framework of the spherical and deformed nuclear optical models are discussed. The calculation of cross sections, angular distributions and other scattering quantities using J. Raynal's code ECIS95 is described. The use of the ECIS method (Equations Couplees en Iterations Sequentielles) in coupled-channels and distorted-wave Born approximation calculations is also reviewed. (author)
Use of nuclear reaction models in cross section calculations
International Nuclear Information System (INIS)
Grimes, S.M.
1975-03-01
The design of fusion reactors will require information about a large number of neutron cross sections in the MeV region. Because of the obvious experimental difficulties, it is probable that not all of the cross sections of interest will be measured. Current direct and pre-equilibrium models can be used to calculate non-statistical contributions to neutron cross sections from information available from charged particle reaction studies; these are added to the calculated statistical contribution. Estimates of the reliability of such calculations can be derived from comparisons with the available data. (3 tables, 12 figures) (U.S.)
Realistic shell-model calculations for Sn isotopes
International Nuclear Information System (INIS)
Covello, A.; Andreozzi, F.; Coraggio, L.; Gargano, A.; Porrino, A.
1997-01-01
We report on a shell-model study of the Sn isotopes in which a realistic effective interaction derived from the Paris free nucleon-nucleon potential is employed. The calculations are performed within the framework of the seniority scheme by making use of the chain-calculation method. This provides practically exact solutions while cutting down the amount of computational work required by a standard seniority-truncated calculation. The behavior of the energy of several low-lying states in the isotopes with A ranging from 122 to 130 is presented and compared with the experimental one. (orig.)
Prioritized List of Research Needs to support MRWFD Case Study Flowsheet Advancement
International Nuclear Information System (INIS)
Law, Jack Douglas; Soelberg, Nicholas Ray
2015-01-01
In FY-13, a case study evaluation was performed of full recycle technologies for both the processing of light-water reactor (LWR) used nuclear fuels as well as fast reactor (FR) fuel in the full recycle option. This effort focused on the identification of the case study processes and the initial preparation of material balance flowsheets for the identified technologies. In identifying the case study flowsheets, it was decided that two cases would be developed: one which identifies the flowsheet as currently developed and another near-term target flowsheet which identifies the flowsheet as envisioned within two years, pending the results of ongoing research. The case study focus is on homogeneous aqueous recycle of the U/TRU resulting from the processing of LWR fuel as feed for metal fuel fabrication. The metal fuel is utilized in a sodium-cooled fast reactor, and the used fast reactor fuel is processed using electrochemical separations. The recovered U/TRU from electrochemical separations is recycled to fuel fabrication and the fast reactor. Waste streams from the aqueous and electrochemical processing are treated and prepared for disposition. Off-gas from the separations and waste processing are also treated. As part of the FY-13 effort, preliminary process unknowns and research needs to advance the near-term target flowsheets were identified. In FY-14, these research needs were updated, expanded and prioritized. This report again updates the prioritized list of research needs based upon results to date in FY-15. The research needs are listed for each of the main portions of the flowsheet: 1) Aqueous headend, 2) Headend tritium pretreatment off-gas, 3) Aqueous U/Pu/Np recovery, 4) Aqueous TRU product solidification, 5) Aqueous actinide/lanthanide separation, 6) Aqueous off-gas treatment, 7) Aqueous HLW management, 8) Treatment of aqueous process wastes, 9) E-chem actinide separations, 10) E-chem off-gas, 11) E-chem HLW management. The identified research needs
Prioritized List of Research Needs to support MRWFD Case Study Flowsheet Advancement
Energy Technology Data Exchange (ETDEWEB)
Law, Jack Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Soelberg, Nicholas Ray [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2015-06-17
In FY-13, a case study evaluation was performed of full recycle technologies for both the processing of light-water reactor (LWR) used nuclear fuels as well as fast reactor (FR) fuel in the full recycle option. This effort focused on the identification of the case study processes and the initial preparation of material balance flowsheets for the identified technologies. In identifying the case study flowsheets, it was decided that two cases would be developed: one which identifies the flowsheet as currently developed and another near-term target flowsheet which identifies the flowsheet as envisioned within two years, pending the results of ongoing research. The case study focus is on homogeneous aqueous recycle of the U/TRU resulting from the processing of LWR fuel as feed for metal fuel fabrication. The metal fuel is utilized in a sodium-cooled fast reactor, and the used fast reactor fuel is processed using electrochemical separations. The recovered U/TRU from electrochemical separations is recycled to fuel fabrication and the fast reactor. Waste streams from the aqueous and electrochemical processing are treated and prepared for disposition. Off-gas from the separations and waste processing are also treated. As part of the FY-13 effort, preliminary process unknowns and research needs to advance the near-term target flowsheets were identified. In FY-14, these research needs were updated, expanded and prioritized. This report again updates the prioritized list of research needs based upon results to date in FY-15. The research needs are listed for each of the main portions of the flowsheet: 1) Aqueous headend, 2) Headend tritium pretreatment off-gas, 3) Aqueous U/Pu/Np recovery, 4) Aqueous TRU product solidification, 5) Aqueous actinide/lanthanide separation, 6) Aqueous off-gas treatment, 7) Aqueous HLW management, 8) Treatment of aqueous process wastes, 9) E-chem actinide separations, 10) E-chem off-gas, 11) E-chem HLW management. The identified research needs
Approximate dynamic fault tree calculations for modelling water supply risks
International Nuclear Information System (INIS)
Lindhe, Andreas; Norberg, Tommy; Rosén, Lars
2012-01-01
Traditional fault tree analysis is not always sufficient when analysing complex systems. To overcome the limitations dynamic fault tree (DFT) analysis is suggested in the literature as well as different approaches for how to solve DFTs. For added value in fault tree analysis, approximate DFT calculations based on a Markovian approach are presented and evaluated here. The approximate DFT calculations are performed using standard Monte Carlo simulations and do not require simulations of the full Markov models, which simplifies model building and in particular calculations. It is shown how to extend the calculations of the traditional OR- and AND-gates, so that information is available on the failure probability, the failure rate and the mean downtime at all levels in the fault tree. Two additional logic gates are presented that make it possible to model a system's ability to compensate for failures. This work was initiated to enable correct analyses of water supply risks. Drinking water systems are typically complex with an inherent ability to compensate for failures that is not easily modelled using traditional logic gates. The approximate DFT calculations are compared to results from simulations of the corresponding Markov models for three water supply examples. For the traditional OR- and AND-gates, and one gate modelling compensation, the errors in the results are small. For the other gate modelling compensation, the error increases with the number of compensating components. The errors are, however, in most cases acceptable with respect to uncertainties in input data. The approximate DFT calculations improve the capabilities of fault tree analysis of drinking water systems since they provide additional and important information and are simple and practically applicable.
Comparison of the performance of net radiation calculation models
DEFF Research Database (Denmark)
Kjærsgaard, Jeppe Hvelplund; Cuenca, R.H.; Martinez-Cob, A.
2009-01-01
. The long-wave radiation models included a physically based model, an empirical model from the literature, and a new empirical model. Both empirical models used only solar radiation as required for meteorological input. The long-wave radiation models were used with model calibration coefficients from......Daily values of net radiation are used in many applications of crop-growth modeling and agricultural water management. Measurements of net radiation are not part of the routine measurement program at many weather stations and are commonly estimated based on other meteorological parameters. Daily...... values of net radiation were calculated using three net outgoing long-wave radiation models and compared to measured values. Four meteorological datasets representing two climate regimes, a sub-humid, high-latitude environment and a semi-arid mid-latitude environment, were used to test the models...
EMPIRE-II statistical model code for nuclear reaction calculations
Energy Technology Data Exchange (ETDEWEB)
Herman, M [International Atomic Energy Agency, Vienna (Austria)
2001-12-15
EMPIRE II is a nuclear reaction code, comprising various nuclear models, and designed for calculations in the broad range of energies and incident particles. A projectile can be any nucleon or Heavy Ion. The energy range starts just above the resonance region, in the case of neutron projectile, and extends up to few hundreds of MeV for Heavy Ion induced reactions. The code accounts for the major nuclear reaction mechanisms, such as optical model (SCATB), Multistep Direct (ORION + TRISTAN), NVWY Multistep Compound, and the full featured Hauser-Feshbach model. Heavy Ion fusion cross section can be calculated within the simplified coupled channels approach (CCFUS). A comprehensive library of input parameters covers nuclear masses, optical model parameters, ground state deformations, discrete levels and decay schemes, level densities, fission barriers (BARFIT), moments of inertia (MOMFIT), and {gamma}-ray strength functions. Effects of the dynamic deformation of a fast rotating nucleus can be taken into account in the calculations. The results can be converted into the ENDF-VI format using the accompanying code EMPEND. The package contains the full EXFOR library of experimental data. Relevant EXFOR entries are automatically retrieved during the calculations. Plots comparing experimental results with the calculated ones can be produced using X4TOC4 and PLOTC4 codes linked to the rest of the system through bash-shell (UNIX) scripts. The graphic user interface written in Tcl/Tk is provided. (author)
Evaluation of calculational and material models for concrete containment structures
International Nuclear Information System (INIS)
Dunham, R.S.; Rashid, Y.R.; Yuan, K.A.
1984-01-01
A computer code utilizing an appropriate finite element, material and constitutive model has been under development as a part of a comprehensive effort by the Electric Power Research Institute (EPRI) to develop and validate a realistic methodology for the ultimate load analysis of concrete containment structures. A preliminary evaluation of the reinforced and prestressed concrete modeling capabilities recently implemented in the ABAQUS-EPGEN code has been completed. This effort focuses on using a state-of-the-art calculational model to predict the behavior of large-scale reinforced concrete slabs tested under uniaxial and biaxial tension to simulate the wall of a typical concrete containment structure under internal pressure. This paper gives comparisons between calculations and experimental measurements for a uniaxially-loaded specimen. The calculated strains compare well with the measured strains in the reinforcing steel; however, the calculations gave diffused cracking patterns that do not agree with the discrete cracking observed in the experiments. Recommendations for improvement of the calculational models are given. (orig.)
Precipitates/Salts Model Calculations for Various Drift Temperature Environments
Energy Technology Data Exchange (ETDEWEB)
P. Marnier
2001-12-20
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation within a repository drift. This work is developed and documented using procedure AP-3.12Q, Calculations, in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The primary objective of this calculation is to predict the effects of evaporation on the abstracted water compositions established in ''EBS Incoming Water and Gas Composition Abstraction Calculations for Different Drift Temperature Environments'' (BSC 2001c). A secondary objective is to predict evaporation effects on observed Yucca Mountain waters for subsequent cement interaction calculations (BSC 2001d). The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b).
The models of internal dose calculation in ICRP
International Nuclear Information System (INIS)
Nakano, Takashi
1995-01-01
There are a lot discussions about internal dose calculation in ICRP. Many efforts are devoted to improvement in models and parameters. In this report, we discuss what kind of models and parameters are used in ICRP. Models are divided into two parts, the dosimetric model and biokinetic model. The former is a mathematical phantom model, and it is mainly developed in ORNL. The results are used in many researchers. The latter is a compartment model and it has a difficulty to decide the parameter values. They are not easy to estimate because of their age dependency. ICRP officially sets values at ages of 3 month, 1 year, 5 year, 10 year, 15 year and adult, and recommends to get values among ages by linear age interpolate. But it is very difficult to solve the basic equation with these values, so we calculate by use of computers. However, it has complex shame and needs long CPU time. We should make approximated equations. The parameter values include much uncertainty because of less experimental data, especially for a child. And these models and parameter values are for Caucasian. We should inquire whether they could correctly describe other than Caucasian. The body size affects the values of calculated SAF, and the differences of metabolism change the biokinetic pattern. (author)
Interactions of model biomolecules. Benchmark CC calculations within MOLCAS
Energy Technology Data Exchange (ETDEWEB)
Urban, Miroslav [Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Bottova 25, SK-917 24 Trnava, Slovakia and Department of Physical and Theoretical Chemistry, Faculty of Natural Scie (Slovakia); Pitoňák, Michal; Neogrády, Pavel; Dedíková, Pavlína [Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava (Slovakia); Hobza, Pavel [Institute of Organic Chemistry and Biochemistry and Center for Complex Molecular Systems and biomolecules, Academy of Sciences of the Czech Republic, Prague (Czech Republic)
2015-01-22
We present results using the OVOS approach (Optimized Virtual Orbitals Space) aimed at enhancing the effectiveness of the Coupled Cluster calculations. This approach allows to reduce the total computer time required for large-scale CCSD(T) calculations about ten times when the original full virtual space is reduced to about 50% of its original size without affecting the accuracy. The method is implemented in the MOLCAS computer program. When combined with the Cholesky decomposition of the two-electron integrals and suitable parallelization it allows calculations which were formerly prohibitively too demanding. We focused ourselves to accurate calculations of the hydrogen bonded and the stacking interactions of the model biomolecules. Interaction energies of the formaldehyde, formamide, benzene, and uracil dimers and the three-body contributions in the cytosine – guanine tetramer are presented. Other applications, as the electron affinity of the uracil affected by solvation are also shortly mentioned.
Laminated materials with plastic interfaces: modeling and calculation
International Nuclear Information System (INIS)
Sandino Aquino de los Ríos, Gilberto; Castañeda Balderas, Rubén; Diaz Diaz, Alberto; Duong, Van Anh; Chataigner, Sylvain; Caron, Jean-François; Ehrlacher, Alain; Foret, Gilles
2009-01-01
In this paper, a model of laminated plates called M4-5N and validated in a previous paper is modified in order to take into account interlaminar plasticity by means of displacement discontinuities at the interfaces. These discontinuities are calculated by adapting a 3D plasticity model. In order to compute the model, a Newton–Raphson-like method is employed. In this method, two sub-problems are considered: one is linear and the other is non-linear. In the linear problem the non-linear equations of the model are linearized and the calculations are performed by making use of a finite element software. By iterating the resolution of each sub-problem, one obtains after convergence the solution of the global problem. The model is then applied to the problem of a double lap, adhesively bonded joint subjected to a tensile load. The adhesive layer is modeled by an elastic–plastic interface. The results of the M4-5N model are compared with those of a commercial finite element software. A good agreement between the two computation techniques is obtained and validates the non-linear calculations proposed in this paper. Finally, the numerical tool and a delamination criterion are applied to predict delamination onset in composite laminates
Use of results from microscopic methods in optical model calculations
International Nuclear Information System (INIS)
Lagrange, C.
1985-11-01
A concept of vectorization for coupled-channel programs based upon conventional methods is first presented. This has been implanted in our program for its use on the CRAY-1 computer. In a second part we investigate the capabilities of a semi-microscopic optical model involving fewer adjustable parameters than phenomenological ones. The two main ingredients of our calculations are, for spherical or well-deformed nuclei, the microscopic optical-model calculations of Jeukenne, Lejeune and Mahaux and nuclear densities from Hartree-Fock-Bogoliubov calculations using the density-dependent force D1. For transitional nuclei deformation-dependent nuclear structure wave functions are employed to weigh the scattering potentials for different shapes and channels [fr
Precision calculations in supersymmetric extensions of the Standard Model
International Nuclear Information System (INIS)
Slavich, P.
2013-01-01
This dissertation is organized as follows: in the next chapter I will summarize the structure of the supersymmetric extensions of the standard model (SM), namely the MSSM (Minimal Supersymmetric Standard Model) and the NMSSM (Next-to-Minimal Supersymmetric Standard Model), I will provide a brief overview of different patterns of SUSY (supersymmetry) breaking and discuss some issues on the renormalization of the input parameters that are common to all calculations of higher-order corrections in SUSY models. In chapter 3 I will review and describe computations on the production of MSSM Higgs bosons in gluon fusion. In chapter 4 I will review results on the radiative corrections to the Higgs boson masses in the NMSSM. In chapter 5 I will review the calculation of BR(B → X s γ in the MSSM with Minimal Flavor Violation (MFV). Finally, in chapter 6 I will briefly summarize the outlook of my future research. (author)
International Nuclear Information System (INIS)
Dimenna, R.A.; Jacobs, R.A.; Taylor, G.A.; Durate, O.E.; Paul, P.K.; Elder, H.H.; Pike, J.A.; Fowler, J.R.; Rutland, P.L.; Gregory, M.V.; Smith III, F.G.; Hang, T.; Subosits, S.G.
2000-01-01
The High Level Waste Salt Disposition Systems Engineering Team was formed on March 13, 1998, under the sponsorship of the Westinghouse Savannah River Company High Level Waste (HLW) Vice President and General Manager. The Team is chartered to identify options, evaluate alternatives, and recommend a selected alternative(s) for processing HLW salt to a permitted waste form
Energy Technology Data Exchange (ETDEWEB)
Elder, H.H.
2001-07-11
The HLW salt waste (salt cake and supernate) now stored at the SRS must be treated to remove insoluble sludge solids and reduce the soluble concentration of radioactive cesium radioactive strontium and transuranic contaminants (principally Pu and Np). These treatments will enable the salt solution to be processed for disposal as saltstone, a solid low-level waste.
Do calculated conflicts in microsimulation model predict number of crashes?
Dijkstra, Atze; Marchesini, Paula; Bijleveld, Frits; Kars, Vincent; Drolenga, Hans; Maarseveen, Martin Van
2010-01-01
A microsimulation model and its calculations are described, and the results that are subsequently used to determine indicators for traffic safety are presented. The method demonstrates which changes occur at the level of traffic flow (number of vehicles per section of road) and at the vehicle level
A shell-model calculation in terms of correlated subsystems
International Nuclear Information System (INIS)
Boisson, J.P.; Silvestre-Brac, B.
1979-01-01
A method for solving the shell-model equations in terms of a basis which includes correlated subsystems is presented. It is shown that the method allows drastic truncations of the basis to be made. The corresponding calculations are easy to perform and can be carried out rapidly
TTS-Polttopuu - cost calculation model for fuelwood
International Nuclear Information System (INIS)
Naett, H.; Ryynaenen, S.
1999-01-01
The TTS-Institutes's Forestry Department has developed a computer based cost-calculation model, 'TTS-Polttopuu', for the calculation of unit costs and resource needs in the harvesting systems for wood chips and split firewood. The model enables to determine the productivity and device cost per operating hour by each working stage of the harvesting system. The calculation model also enables the user to find out how changes in the productivity and cost bases of different harvesting chains influence the unit cost of the whole system. The harvesting chain includes the cutting of delimbed and non-delimbed fuelwood, forest haulage, road transportation, chipping and chopping of longwood at storage. This individually operating software was originally developed to serve research needs, but it also serves the needs of the forestry and agricultural education, training and extension as well as individual firewood producers. The system requirements for this cost calculation model are at least 486- level processor with the Windows 95/98 -operating system, 16 MB of memory (RAM) and 5 MB of available hard-disk. This development work was carried out in conjunction with the nation-wide BIOENERGY-research programme. (orig.)
Calculation of extreme wind atlases using mesoscale modeling. Final report
DEFF Research Database (Denmark)
Larsén, Xiaoli Guo; Badger, Jake
This is the final report of the project PSO-10240 "Calculation of extreme wind atlases using mesoscale modeling". The overall objective is to improve the estimation of extreme winds by developing and applying new methodologies to confront the many weaknesses in the current methodologies as explai...
Overview of models allowing calculation of activity coefficients
Energy Technology Data Exchange (ETDEWEB)
Jaussaud, C.; Sorel, C
2004-07-01
Activity coefficients must be estimated to accurately quantify the extraction equilibrium involved in spent fuel reprocessing. For these calculations, binary data are required for each electrolyte over a concentration range sometimes exceeding the maximum solubility. The activity coefficients must be extrapolated to model the behavior of binary supersaturated aqueous solution. According to the bibliography, the most suitable models are based on the local composition concept. (authors)
Shell model calculations for stoichiometric Na β-alumina
International Nuclear Information System (INIS)
Wang, J.C.
1985-01-01
Walker and Catlow recently reported the results of their shell model calculations for the structure and transport of Na β-alumina (Naβ). The main computer programs used by Walker and Catlow for their calculations are PLUTO and HADES III. The latter, a recent version of HADES II written for cubic crystals, is believed to be applicable to defects in crystals of both cubic and hexagonal symmetry. PLUTO is usually used in calculating properties of perfect crystals before defects are introduced into the structure. Walker and Catlow claim that, in some respects, their models are superior to those of Wang et al. Yet, their results are quite different from those observed experimentally. In this work these differences are investigated by using a computer program designed to calculate lattice energies for s Naβ using the same shell model parameters adopted by Walker and Catlow. The core and shell positions of all ions, as well as the lattice parameters, were fully relaxed. The calculated energy difference between aBR and BR sites (0.33 eV) is about twice as large as that reported by Walker and Catlow. The present results also show that the relaxed oxygen ion positions next to the conduction plane in this case are displaced from their observed sites reported. When the core-shell spring constant of the oxygen ion was adjusted to minimize these displacements, the above-mentioned energy difference increased to about 0.56 eV. These results cast doubt on the fluid conduction plane structure suggested by Walker and Catlow and on the defect structure and activation energy obtained from their calculations
Cluster model calculations of alpha decays across the periodic table
International Nuclear Information System (INIS)
Merchant, A.C.; Buck, B.
1988-10-01
The cluster model of Buck, Dover and Vary has been used to calculate partial widths for alpha decay from the ground states of all nuclei for which experimental measurements exist. The cluster-core potential is represented by a simple three-parameter form having fixed diffuseness, a radius which scales as A 1/3 and a depth which is adjusted to fit the Q-value of the particular decay. The calculations yield excellent agreement with the vast majority of the available data, and some typical examples are presented. (author) [pt
Modelling of Control Bars in Calculations of Boiling Water Reactors
International Nuclear Information System (INIS)
Khlaifi, A.; Buiron, L.
2004-01-01
The core of a nuclear reactor is generally composed of a neat assemblies of fissile material from where neutrons were descended. In general, the energy of fission is extracted by a fluid serving to cool clusters. A reflector is arranged around the assemblies to reduce escaping of neutrons. This is made outside the reactor core. Different mechanisms of reactivity are generally necessary to control the chain reaction. Manoeuvring of Boiling Water Reactor takes place by controlling insertion of absorbent rods to various places of the core. If no blocked assembly calculations are known and mastered, blocked assembly neutronic calculation are delicate and often treated by case to case in present studies [1]. Answering the question how to model crossbar for the control of a boiling water reactor ? requires the choice of a representation level for every chain of variables, the physical model, and its representing equations, etc. The aim of this study is to select the best applicable parameter serving to calculate blocked assembly of a Boiling Water Reactor. This will be made through a range of representative configurations of these reactors and used absorbing environment, in order to illustrate strategies of modelling in the case of an industrial calculation. (authors)
Modelling and parallel calculation of a kinetic boundary layer
International Nuclear Information System (INIS)
Perlat, Jean Philippe
1998-01-01
This research thesis aims at addressing reliability and cost issues in the calculation by numeric simulation of flows in transition regime. The first step has been to reduce calculation cost and memory space for the Monte Carlo method which is known to provide performance and reliability for rarefied regimes. Vector and parallel computers allow this objective to be reached. Here, a MIMD (multiple instructions, multiple data) machine has been used which implements parallel calculation at different levels of parallelization. Parallelization procedures have been adapted, and results showed that parallelization by calculation domain decomposition was far more efficient. Due to reliability issue related to the statistic feature of Monte Carlo methods, a new deterministic model was necessary to simulate gas molecules in transition regime. New models and hyperbolic systems have therefore been studied. One is chosen which allows thermodynamic values (density, average velocity, temperature, deformation tensor, heat flow) present in Navier-Stokes equations to be determined, and the equations of evolution of thermodynamic values are described for the mono-atomic case. Numerical resolution of is reported. A kinetic scheme is developed which complies with the structure of all systems, and which naturally expresses boundary conditions. The validation of the obtained 14 moment-based model is performed on shock problems and on Couette flows [fr
Diffusion theory model for optimization calculations of cold neutron sources
International Nuclear Information System (INIS)
Azmy, Y.Y.
1987-01-01
Cold neutron sources are becoming increasingly important and common experimental facilities made available at many research reactors around the world due to the high utility of cold neutrons in scattering experiments. The authors describe a simple two-group diffusion model of an infinite slab LD 2 cold source. The simplicity of the model permits to obtain an analytical solution from which one can deduce the reason for the optimum thickness based solely on diffusion-type phenomena. Also, a second more sophisticated model is described and the results compared to a deterministic transport calculation. The good (particularly qualitative) agreement between the results suggests that diffusion theory methods can be used in parametric and optimization studies to avoid the generally more expensive transport calculations
Hybrid Reduced Order Modeling Algorithms for Reactor Physics Calculations
Bang, Youngsuk
Reduced order modeling (ROM) has been recognized as an indispensable approach when the engineering analysis requires many executions of high fidelity simulation codes. Examples of such engineering analyses in nuclear reactor core calculations, representing the focus of this dissertation, include the functionalization of the homogenized few-group cross-sections in terms of the various core conditions, e.g. burn-up, fuel enrichment, temperature, etc. This is done via assembly calculations which are executed many times to generate the required functionalization for use in the downstream core calculations. Other examples are sensitivity analysis used to determine important core attribute variations due to input parameter variations, and uncertainty quantification employed to estimate core attribute uncertainties originating from input parameter uncertainties. ROM constructs a surrogate model with quantifiable accuracy which can replace the original code for subsequent engineering analysis calculations. This is achieved by reducing the effective dimensionality of the input parameter, the state variable, or the output response spaces, by projection onto the so-called active subspaces. Confining the variations to the active subspace allows one to construct an ROM model of reduced complexity which can be solved more efficiently. This dissertation introduces a new algorithm to render reduction with the reduction errors bounded based on a user-defined error tolerance which represents the main challenge of existing ROM techniques. Bounding the error is the key to ensuring that the constructed ROM models are robust for all possible applications. Providing such error bounds represents one of the algorithmic contributions of this dissertation to the ROM state-of-the-art. Recognizing that ROM techniques have been developed to render reduction at different levels, e.g. the input parameter space, the state space, and the response space, this dissertation offers a set of novel
TTS-Polttopuu - cost calculation model for fuelwood
International Nuclear Information System (INIS)
Naett, H.; Ryynaenen, S.
1998-01-01
The TTS-Institutes's Forestry Department has developed a computer based costcalculation model, 'TTS-Polttopuu', for the calculation of unit costs and resource needs in the harvesting systems for wood chips and split firewood. The model enables to determine the productivity and device cost per operating hour by each working stage of the harvesting system. The calculation model also enables the user to find out how changes in the productivity and cost bases of different harvesting chains influence the unit cost of the whole system. The harvesting chain includes the cutting of delimbed and non-delimbed fuelwood, forest haulage, road transportation chipping and chopping of longwood at storage. This individually operating software was originally developed to serve research needs, but it also serves the needs of the forestry and agricultural education, training and extension as well as individual firewood producers. The system requirements for this cost calculation model are at least 486-level processor with the Windows 95/98 -operating system, 16 MB of memory (RAM) and 5 MB of available hard-disk. This development work was carried out in conjunction with the nation-wide BIOENERGY Research Programme. (orig.)
Calculations of dose distributions using a neural network model
International Nuclear Information System (INIS)
Mathieu, R; Martin, E; Gschwind, R; Makovicka, L; Contassot-Vivier, S; Bahi, J
2005-01-01
The main goal of external beam radiotherapy is the treatment of tumours, while sparing, as much as possible, surrounding healthy tissues. In order to master and optimize the dose distribution within the patient, dosimetric planning has to be carried out. Thus, for determining the most accurate dose distribution during treatment planning, a compromise must be found between the precision and the speed of calculation. Current techniques, using analytic methods, models and databases, are rapid but lack precision. Enhanced precision can be achieved by using calculation codes based, for example, on Monte Carlo methods. However, in spite of all efforts to optimize speed (methods and computer improvements), Monte Carlo based methods remain painfully slow. A newer way to handle all of these problems is to use a new approach in dosimetric calculation by employing neural networks. Neural networks (Wu and Zhu 2000 Phys. Med. Biol. 45 913-22) provide the advantages of those various approaches while avoiding their main inconveniences, i.e., time-consumption calculations. This permits us to obtain quick and accurate results during clinical treatment planning. Currently, results obtained for a single depth-dose calculation using a Monte Carlo based code (such as BEAM (Rogers et al 2003 NRCC Report PIRS-0509(A) rev G)) require hours of computing. By contrast, the practical use of neural networks (Mathieu et al 2003 Proceedings Journees Scientifiques Francophones, SFRP) provides almost instant results and quite low errors (less than 2%) for a two-dimensional dosimetric map
Effects of solvent-extraction contactor selection on flowsheet and facility design
International Nuclear Information System (INIS)
Whatley, M.E.
1982-01-01
The notion is developed that the selection of a solvent extraction contactor is part of a more general development of principles and philosophy guiding the overall plant design. Specifically, the requirements and constraints placed on the plant by the solvent extraction system must be consistent with those imposed by the other operations, which generally are more expensive and more complicated. Were a conservative philosophy employed throughout the plant, the choice of pulsed columns seem correct. Were the plant intended to employ modern techniques and state-of-the-art technology, particularly in remote maintenance and process control, the selection of centrifugal contactors seems appropriate. The process improvements attainable from employing more stages in a more tightly controlled solvent extraction system seem marginal at present when applied to conventional flowsheets, although the cost-benefit may be attractive in a modern plant. The potential for improvement through major flowsheet modification can not presently be assessed quantitatively
Model and calculation of in situ stresses in anisotropic formations
Energy Technology Data Exchange (ETDEWEB)
Yuezhi, W.; Zijun, L.; Lixin, H. [Jianghan Petroleum Institute, (China)
1997-08-01
In situ stresses in transversely isotropic material in relation to wellbore stability have been investigated. Equations for three horizontal in- situ stresses and a new formation fracture pressure model were described, and the methodology for determining the elastic parameters of anisotropic rocks in the laboratory was outlined. Results indicate significantly smaller differences between theoretically calculated pressures and actual formation pressures than results obtained by using the isotropic method. Implications for improvements in drilling efficiency were reviewed. 13 refs., 6 figs.
Perturbation theory instead of large scale shell model calculations
International Nuclear Information System (INIS)
Feldmeier, H.; Mankos, P.
1977-01-01
Results of large scale shell model calculations for (sd)-shell nuclei are compared with a perturbation theory provides an excellent approximation when the SU(3)-basis is used as a starting point. The results indicate that perturbation theory treatment in an SU(3)-basis including 2hω excitations should be preferable to a full diagonalization within the (sd)-shell. (orig.) [de
Calculation of relativistic model stars using Regge calculus
International Nuclear Information System (INIS)
Porter, J.
1987-01-01
A new approach to the Regge calculus, developed in a previous paper, is used in conjunction with the velocity potential version of relativistic fluid dynamics due to Schutz [1970, Phys. Rev., D, 2, 2762] to calculate relativistic model stars. The results are compared with those obtained when the Tolman-Oppenheimer-Volkov equations are solved by other numerical methods. The agreement is found to be excellent. (author)
Actual waste demonstration of the nitric-glycolic flowsheet for sludge batch 9 qualification
Energy Technology Data Exchange (ETDEWEB)
Newell, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martino, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reboul, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coleman, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Johnson, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-03-09
For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs qualification testing to demonstrate that the sludge batch is processable. Based on the results of this actual-waste qualification and previous simulant studies, SRNL recommends implementation of the nitric-glycolic acid flowsheet in DWPF. Other recommendations resulting from this demonstration are reported in section 5.0.
Structure-dynamic model verification calculation of PWR 5 tests
International Nuclear Information System (INIS)
Engel, R.
1980-02-01
Within reactor safety research project RS 16 B of the German Federal Ministry of Research and Technology (BMFT), blowdown experiments are conducted at Battelle Institut e.V. Frankfurt/Main using a model reactor pressure vessel with a height of 11,2 m and internals corresponding to those in a PWR. In the present report the dynamic loading on the pressure vessel internals (upper perforated plate and barrel suspension) during the DWR 5 experiment are calculated by means of a vertical and horizontal dynamic model using the CESHOCK code. The equations of motion are resolved by direct integration. (orig./RW) [de
Development and Testing of an Americium/Lanthanide Separation Flowsheet Using Sodium Bismuthate
Energy Technology Data Exchange (ETDEWEB)
Jack Law; Bruce Mincher; Troy Garn; Mitchell Greenhalgh; Nicholas Schmitt; Veronica Rutledge
2014-04-01
The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term heat load of material interred in a future high-level waste repository. A separation process amenable to process scale-up remains elusive. Given only subtle chemistry differences within and between the ions of the trivalent actinide and lanthanide series this separation is challenging ; however, higher oxidation states of americium can be prepared using sodium bismuthate and separated via solvent extraction using diamylamylphosphonate (DAAP) extraction. Among the other trivalent metals only Ce is also oxidized and extracted. Due to the long-term instability of Am(VI) , the loaded organic phase is readily selectively stripped to partition the actinide to a new acidic aqueous phase. Batch extraction distribution ratio measurements were used to design a flowsheet to accomplish this separation. Additionally, crossflow filtration was investigated as a method to filter the bismuthate solids from the feed solution prior to extraction. Results of the filtration studies, flowsheet development work and flowsheet performance testing using a centrifugal contactor are detailed.
Sludge batch 9 simulant runs using the nitric-glycolic acid flowsheet
Energy Technology Data Exchange (ETDEWEB)
Lambert, D. P. [Savannah River Site (SRS), Aiken, SC (United States); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States); Brandenburg, C. H. [Savannah River Site (SRS), Aiken, SC (United States); Luther, M. C. [Savannah River Site (SRS), Aiken, SC (United States); Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States); Woodham, W. H. [Savannah River Site (SRS), Aiken, SC (United States)
2016-11-01
Testing was completed to develop a Sludge Batch 9 (SB9) nitric-glycolic acid chemical process flowsheet for the Defense Waste Processing Facility’s (DWPF) Chemical Process Cell (CPC). CPC simulations were completed using SB9 sludge simulant, Strip Effluent Feed Tank (SEFT) simulant and Precipitate Reactor Feed Tank (PRFT) simulant. Ten sludge-only Sludge Receipt and Adjustment Tank (SRAT) cycles and four SRAT/Slurry Mix Evaporator (SME) cycles, and one actual SB9 sludge (SRAT/SME cycle) were completed. As has been demonstrated in over 100 simulations, the replacement of formic acid with glycolic acid virtually eliminates the CPC’s largest flammability hazards, hydrogen and ammonia. Recommended processing conditions are summarized in section 3.5.1. Testing demonstrated that the interim chemistry and Reduction/Oxidation (REDOX) equations are sufficient to predict the composition of DWPF SRAT product and SME product. Additional reports will finalize the chemistry and REDOX equations. Additional testing developed an antifoam strategy to minimize the hexamethyldisiloxane (HMDSO) peak at boiling, while controlling foam based on testing with simulant and actual waste. Implementation of the nitric-glycolic acid flowsheet in DWPF is recommended. This flowsheet not only eliminates the hydrogen and ammonia hazards but will lead to shorter processing times, higher elemental mercury recovery, and more concentrated SRAT and SME products. The steady pH profile is expected to provide flexibility in processing the high volume of strip effluent expected once the Salt Waste Processing Facility starts up.
HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS
Energy Technology Data Exchange (ETDEWEB)
Gorensek, M.
2011-07-06
Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.
a Proposed Benchmark Problem for Scatter Calculations in Radiographic Modelling
Jaenisch, G.-R.; Bellon, C.; Schumm, A.; Tabary, J.; Duvauchelle, Ph.
2009-03-01
Code Validation is a permanent concern in computer modelling, and has been addressed repeatedly in eddy current and ultrasonic modeling. A good benchmark problem is sufficiently simple to be taken into account by various codes without strong requirements on geometry representation capabilities, focuses on few or even a single aspect of the problem at hand to facilitate interpretation and to avoid that compound errors compensate themselves, yields a quantitative result and is experimentally accessible. In this paper we attempt to address code validation for one aspect of radiographic modeling, the scattered radiation prediction. Many NDT applications can not neglect scattered radiation, and the scatter calculation thus is important to faithfully simulate the inspection situation. Our benchmark problem covers the wall thickness range of 10 to 50 mm for single wall inspections, with energies ranging from 100 to 500 keV in the first stage, and up to 1 MeV with wall thicknesses up to 70 mm in the extended stage. A simple plate geometry is sufficient for this purpose, and the scatter data is compared on a photon level, without a film model, which allows for comparisons with reference codes like MCNP. We compare results of three Monte Carlo codes (McRay, Sindbad and Moderato) as well as an analytical first order scattering code (VXI), and confront them to results obtained with MCNP. The comparison with an analytical scatter model provides insights into the application domain where this kind of approach can successfully replace Monte-Carlo calculations.
Ordinary Mathematical Models in Calculating the Aviation GTE Parameters
Directory of Open Access Journals (Sweden)
E. A. Khoreva
2017-01-01
Full Text Available The paper presents the analytical review results of the ordinary mathematical models of the operating process used to study aviation GTE parameters and characteristics at all stages of its creation and operation. Considers the mathematical models of the zero and the first level, which are mostly used when solving typical problems in calculating parameters and characteristics of engines.Presents a number of practical problems arising in designing aviation GTE for various applications.The application of mathematical models of the zero-level engine can be quite appropriate when the engine is considered as a component in the aircraft system to estimate its calculated individual flight performance or when modeling the flight cycle of the aircrafts of different purpose.The paper demonstrates that introduction of correction functions into the first-level mathematical models in solving typical problems (influence of the Reynolds number, characteristics deterioration of the units during the overhaul period of engine, as well as influence of the flow inhomogeneity at the inlet because of manufacturing tolerance, etc. enables providing a sufficient engineering estimate accuracy to reflect a realistic operating process in the engine and its elements.
Freeway travel speed calculation model based on ETC transaction data.
Weng, Jiancheng; Yuan, Rongliang; Wang, Ru; Wang, Chang
2014-01-01
Real-time traffic flow operation condition of freeway gradually becomes the critical information for the freeway users and managers. In fact, electronic toll collection (ETC) transaction data effectively records operational information of vehicles on freeway, which provides a new method to estimate the travel speed of freeway. First, the paper analyzed the structure of ETC transaction data and presented the data preprocess procedure. Then, a dual-level travel speed calculation model was established under different levels of sample sizes. In order to ensure a sufficient sample size, ETC data of different enter-leave toll plazas pairs which contain more than one road segment were used to calculate the travel speed of every road segment. The reduction coefficient α and reliable weight θ for sample vehicle speed were introduced in the model. Finally, the model was verified by the special designed field experiments which were conducted on several freeways in Beijing at different time periods. The experiments results demonstrated that the average relative error was about 6.5% which means that the freeway travel speed could be estimated by the proposed model accurately. The proposed model is helpful to promote the level of the freeway operation monitoring and the freeway management, as well as to provide useful information for the freeway travelers.
Mathematical model of kinetostatithic calculation of flat lever mechanisms
Directory of Open Access Journals (Sweden)
A. S. Sidorenko
2016-01-01
Full Text Available Currently widely used graphical-analytical methods of analysis largely obsolete, replaced by various analytical methods using computer technology. Therefore, of particular interest is the development of a mathematical model kinetostatical calculation mechanisms in the form of library procedures of calculation for all powered two groups Assyrians (GA and primary level. Before resorting to the appropriate procedure that computes all the forces in the kinematic pairs, you need to compute inertial forces, moments of forces of inertia and all external forces and moments acting on this GA. To this end shows the design diagram of the power analysis for each species GA of the second class, as well as the initial link. Finding reactions in the internal and external kinematic pairs based on equilibrium conditions with the account of forces of inertia and moments of inertia forces (Dalembert principle. Thus obtained equations of kinetostatical for their versatility have been solved by the Cramer rule. Thus, for each GA of the second class were found all 6 unknowns: the forces in the kinematic pairs, the directions of these forces as well as forces the shoulders. If we study kinetostatic mechanism with parallel consolidation of two GA in the initial link, in this case, power is the geometric sum of the forces acting on the primary link from the discarded GA. Thus, the obtained mathematical model kinetostatical calculation mechanisms in the form of libraries of mathematical procedures for determining reactions of all GA of the second class. The mathematical model kinetostatical calculation makes it relatively simple to implement its software implementation.
Hirarchical emotion calculation model for virtual human modellin - biomed 2010.
Zhao, Yue; Wright, David
2010-01-01
This paper introduces a new emotion generation method for virtual human modelling. The method includes a novel hierarchical emotion structure, a group of emotion calculation equations and a simple heuristics decision making mechanism, which enables virtual humans to perform emotionally in real-time according to their internal and external factors. Emotion calculation equations used in this research were derived from psychologic emotion measurements. Virtual humans can utilise the information in virtual memory and emotion calculation equations to generate their own numerical emotion states within the hierarchical emotion structure. Those emotion states are important internal references for virtual humans to adopt appropriate behaviours and also key cues for their decision making. A simple heuristics theory is introduced and integrated into decision making process in order to make the virtual humans decision making more like a real human. A data interface which connects the emotion calculation and the decision making structure together has also been designed and simulated to test the method in Virtools environment.
Modeling and Calculation of Dent Based on Pipeline Bending Strain
Directory of Open Access Journals (Sweden)
Qingshan Feng
2016-01-01
Full Text Available The bending strain of long-distance oil and gas pipelines can be calculated by the in-line inspection tool which used inertial measurement unit (IMU. The bending strain is used to evaluate the strain and displacement of the pipeline. During the bending strain inspection, the dent existing in the pipeline can affect the bending strain data as well. This paper presents a novel method to model and calculate the pipeline dent based on the bending strain. The technique takes inertial mapping data from in-line inspection and calculates depth of dent in the pipeline using Bayesian statistical theory and neural network. To verify accuracy of the proposed method, an in-line inspection tool is used to inspect pipeline to gather data. The calculation of dent shows the method is accurate for the dent, and the mean relative error is 2.44%. The new method provides not only strain of the pipeline dent but also the depth of dent. It is more benefit for integrity management of pipeline for the safety of the pipeline.
Theoretical model for calculation of molecular stopping power
International Nuclear Information System (INIS)
Xu, Y.J.
1984-01-01
A modified local plasma model based on the work of Linhard-Winther, Bethe, Brown, and Walske is established. The Gordon-Kim's molecular charged density model is employed to obtain a formula to evaluate the stopping power of many useful molecular systems. The stopping power of H 2 and He gas was calculated for incident proton energy ranging from 100 KeV to 2.5 MeV. The stopping power of O 2 , N 2 , and water vapor was also calculated for incident proton energy ranging from 40 keV to 2.5 MeV. Good agreement with experimental data was obtained. A discussion of molecular effects leading to departure from Bragg's rule is presented. The equipartition rule and the effect of nuclear momentum recoiling in stopping power are also discussed in the appendix. The calculation procedure presented hopefully can easily be extended to include the most useful organic systems such as the molecules composed of carbon, nitrogen, hydrogen and oxygen which are useful in radiation protection field
Total energy calculations from self-energy models
International Nuclear Information System (INIS)
Sanchez-Friera, P.
2001-06-01
Density-functional theory is a powerful method to calculate total energies of large systems of interacting electrons. The usefulness of this method, however, is limited by the fact that an approximation is required for the exchange-correlation energy. Currently used approximations (LDA and GGA) are not sufficiently accurate in many physical problems, as for instance the study of chemical reactions. It has been shown that exchange-correlation effects can be accurately described via the self-energy operator in the context of many-body perturbation theory. This is, however, a computationally very demanding approach. In this thesis a new scheme for calculating total energies is proposed, which combines elements from many-body perturbation theory and density-functional theory. The exchange-correlation energy functional is built from a simplified model of the self-energy, that nevertheless retains the main features of the exact operator. The model is built in such way that the computational effort is not significantly increased with respect to that required in a typical density-functional theory calculation. (author)
Calculations of the electrostatic potential adjacent to model phospholipid bilayers.
Peitzsch, R M; Eisenberg, M; Sharp, K A; McLaughlin, S
1995-03-01
We used the nonlinear Poisson-Boltzmann equation to calculate electrostatic potentials in the aqueous phase adjacent to model phospholipid bilayers containing mixtures of zwitterionic lipids (phosphatidylcholine) and acidic lipids (phosphatidylserine or phosphatidylglycerol). The aqueous phase (relative permittivity, epsilon r = 80) contains 0.1 M monovalent salt. When the bilayers contain equipotential surfaces are discrete domes centered over the negatively charged lipids and are approximately twice the value calculated using Debye-Hückel theory. When the bilayers contain > 25% acidic lipid, the -25 mV equipotential profiles are essentially flat and agree well with the values calculated using Gouy-Chapman theory. When the bilayers contain 100% acidic lipid, all of the equipotential surfaces are flat and agree with Gouy-Chapman predictions (including the -100 mV surface, which is located only 1 A from the outermost atoms). Even our model bilayers are not simple systems: the charge on each lipid is distributed over several atoms, these partial charges are non-coplanar, there is a 2 A ion-exclusion region (epsilon r = 80) adjacent to the polar headgroups, and the molecular surface is rough. We investigated the effect of these four factors using smooth (or bumpy) epsilon r = 2 slabs with embedded point charges: these factors had only minor effects on the potential in the aqueous phase.
Improved SVR Model for Multi-Layer Buildup Factor Calculation
International Nuclear Information System (INIS)
Trontl, K.; Pevec, D.; Smuc, T.
2006-01-01
The accuracy of point kernel method applied in gamma ray dose rate calculations in shielding design and radiation safety analysis is limited by the accuracy of buildup factors used in calculations. Although buildup factors for single-layer shields are well defined and understood, buildup factors for stratified shields represent a complex physical problem that is hard to express in mathematical terms. The traditional approach for expressing buildup factors of multi-layer shields is through semi-empirical formulas obtained by fitting the results of transport theory or Monte Carlo calculations. Such an approach requires an ad-hoc definition of the fitting function and often results with numerous and usually inadequately explained and defined correction factors added to the final empirical formula. Even more, finally obtained formulas are generally limited to a small number of predefined combinations of materials within relatively small range of gamma ray energies and shield thicknesses. Recently, a new approach has been suggested by the authors involving one of machine learning techniques called Support Vector Machines, i.e., Support Vector Regression (SVR). Preliminary investigations performed for double-layer shields revealed great potential of the method, but also pointed out some drawbacks of the developed model, mostly related to the selection of one of the parameters describing the problem (material atomic number), and the method in which the model was designed to evolve during the learning process. It is the aim of this paper to introduce a new parameter (single material buildup factor) that is to replace the existing material atomic number as an input parameter. The comparison of two models generated by different input parameters has been performed. The second goal is to improve the evolution process of learning, i.e., the experimental computational procedure that provides a framework for automated construction of complex regression models of predefined
Freight Calculation Model: A Case Study of Coal Distribution
Yunianto, I. T.; Lazuardi, S. D.; Hadi, F.
2018-03-01
Coal has been known as one of energy alternatives that has been used as energy source for several power plants in Indonesia. During its transportation from coal sites to power plant locations is required the eligible shipping line services that are able to provide the best freight rate. Therefore, this study aims to obtain the standardized formulations for determining the ocean freight especially for coal distribution based on the theoretical concept. The freight calculation model considers three alternative transport modes commonly used in coal distribution: tug-barge, vessel and self-propelled barge. The result shows there are two cost components very dominant in determining the value of freight with the proportion reaching 90% or even more, namely: time charter hire and fuel cost. Moreover, there are three main factors that have significant impacts on the freight calculation, which are waiting time at ports, time charter rate and fuel oil price.
Nuclear model calculations on cyclotron production of {sup 51}Cr
Energy Technology Data Exchange (ETDEWEB)
Kakavand, Tayeb [Imam Khomeini International Univ., Qazvin (Iran, Islamic Republic of). Dept. of Physics; Aboudzadeh, Mohammadreza [Nuclear Science and Technology Research Institute/AEOI, Karaj (Iran, Islamic Republic of). Agricultural, Medical and Industrial Research School; Farahani, Zahra; Eslami, Mohammad [Zanjan Univ. (Iran, Islamic Republic of). Dept. of Physics
2015-12-15
{sup 51}Cr (T{sub 1/2} = 27.7 d), which decays via electron capture (100 %) with 320 keV gamma emission (9.8 %), is a radionuclide with still a large application in biological studies. In this work, ALICE/ASH and TALYS nuclear model codes along with some adjustments are used to calculate the excitation functions for proton, deuteron, α-particle and neutron induced on various targets leading to the production of {sup 51}Cr radioisotope. The production yields of {sup 51}Cr from various reactions are determined using the excitation function calculations and stopping power data. The results are compared with corresponding experimental data and discussed from point of view of feasibility.
Optical model calculation of neutron-nucleus scattering cross sections
International Nuclear Information System (INIS)
Smith, M.E.; Camarda, H.S.
1980-01-01
A program to calculate the total, elastic, reaction, and differential cross section of a neutron interacting with a nucleus is described. The interaction between the neutron and the nucleus is represented by a spherically symmetric complex potential that includes spin-orbit coupling. This optical model problem is solved numerically, and is treated with the partial-wave formalism of scattering theory. The necessary scattering theory required to solve this problem is briefly stated. Then, the numerical methods used to integrate the Schroedinger equation, calculate derivatives, etc., are described, and the results of various programming tests performed are presented. Finally, the program is discussed from a user's point of view, and it is pointed out how and where the program (OPTICAL) can be changed to satisfy particular needs
Computational techniques used in the development of coprocessing flowsheets
International Nuclear Information System (INIS)
Groenier, W.S.; Mitchell, A.D.; Jubin, R.T.
1979-01-01
The computer program SEPHIS, developed to aid in determining optimum solvent extraction conditions for the reprocessing of nuclear power reactor fuels by the Purex method, is described. The program employs a combination of approximate mathematical equilibrium expressions and a transient, stagewise-process calculational method to allow stage and product-stream concentrations to be predicted with accuracy and reliability. The possible applications to inventory control for nuclear material safeguards, nuclear criticality analysis, and process analysis and control are of special interest. The method is also applicable to other counntercurrent liquid--liquid solvent extraction processes having known chemical kinetics, that may involve multiple solutes and are performed in conventional contacting equipment
A relativistic point coupling model for nuclear structure calculations
International Nuclear Information System (INIS)
Buervenich, T.; Maruhn, J.A.; Madland, D.G.; Reinhard, P.G.
2002-01-01
A relativistic point coupling model is discussed focusing on a variety of aspects. In addition to the coupling using various bilinear Dirac invariants, derivative terms are also included to simulate finite-range effects. The formalism is presented for nuclear structure calculations of ground state properties of nuclei in the Hartree and Hartree-Fock approximations. Different fitting strategies for the determination of the parameters have been applied and the quality of the fit obtainable in this model is discussed. The model is then compared more generally to other mean-field approaches both formally and in the context of applications to ground-state properties of known and superheavy nuclei. Perspectives for further extensions such as an exact treatment of the exchange terms using a higher-order Fierz transformation are discussed briefly. (author)
Model for calculation of electrostatic contribution into protein stability
Kundrotas, Petras; Karshikoff, Andrey
2003-03-01
Existing models of the denatured state of proteins consider only one possible spatial distribution of protein charges and therefore are applicable to a limited number of cases. In this presentation a more general framework for the modeling of the denatured state is proposed. It is based on the assumption that the titratable groups of an unfolded protein can adopt a quasi-random distribution, restricted by the protein sequence. The model was tested on two proteins, barnase and N-terminal domain of the ribosomal protein L9. The calculated free energy of denaturation, Δ G( pH), reproduces the experimental data essentially better than the commonly used null approximation (NA). It was demonstrated that the seemingly good agreement with experimental data obtained by NA originates from the compensatory effect between the pair-wise electrostatic interactions and the desolvation energy of the individual sites. It was also found that the ionization properties of denatured proteins are influenced by the protein sequence.
Physical model and calculation code for fuel coolant interactions
International Nuclear Information System (INIS)
Goldammer, H.; Kottowski, H.
1976-01-01
A physical model is proposed to describe fuel coolant interactions in shock-tube geometry. According to the experimental results, an interaction model which divides each cycle into three phases is proposed. The first phase is the fuel-coolant-contact, the second one is the ejection and recently of the coolant, and the third phase is the impact and fragmentation. Physical background of these phases are illustrated in the first part of this paper. Mathematical expressions of the model are exposed in the second part. A principal feature of the computational method is the consistent application of the fourier-equation throughout the whole interaction process. The results of some calculations, performed for different conditions are compiled in attached figures. (Aoki, K.)
Intravascular brachytherapy: a model for the calculation of the dose
International Nuclear Information System (INIS)
Pirchio, Rosana; Martin, Gabriela; Rivera, Elena; Cricco, Graciela; Cocca, Claudia; Gutierrez, Alicia; Nunez, Mariel; Bergoc, Rosa; Guzman, Luis; Belardi, Diego
2002-01-01
In this study we present the radiation dose distribution for a theoretical model with Montecarlo simulation, and based on an experimental model developed for the study of the prevention of restenosis post-angioplasty employing intravascular brachytherapy. In the experimental in vivo model, the atherosclerotic plaques were induced in femoral arteries of male New Zealand rabbits through surgical intervention and later administration of cholesterol enriched diet. For the intravascular irradiation we employed a 32P source contained within the balloon used for the angioplasty. The radiation dose distributions were calculated using the Monte Carlo code MCNP4B according to a segment of a simulated artery. We studied the radiation dose distribution in the axial and radial directions for different thickness of the atherosclerotic plaques. The results will be correlated with the biologic effects observed by means of histological analysis of the irradiated arteries (Au)
MODEL OF FEES CALCULATION FOR ACCESS TO TRACK INFRASTRUCTURE FACILITIES
Directory of Open Access Journals (Sweden)
M. I. Mishchenko
2014-12-01
Full Text Available Purpose. The purpose of the article is to develop a one- and two-element model of the fees calculation for the use of track infrastructure of Ukrainian railway transport. Methodology. On the basis of this one can consider that when planning the planned preventive track repair works and the amount of depreciation charges the guiding criterion is not the amount of progress it is the operating life of the track infrastructure facilities. The cost of PPTRW is determined on the basis of the following: the classification track repairs; typical technological processes for track repairs; technology based time standards for PPTRW; costs for the work of people, performing the PPTRW, their hourly wage rates according to the Order 98-Ts; the operating cost of machinery; regulated list; norms of expenditures and costs of materials and products (they have the largest share of the costs for repairs; railway rates; average distances for transportation of materials used during repair; standards of general production expenses and the administrative costs. Findings. The models offered in article allow executing the objective account of expenses in travelling facilities for the purpose of calculation of the proved size of indemnification and necessary size of profit, the sufficient enterprises for effective activity of a travelling infrastructure. Originality. The methodological bases of determination the fees (payments for the use of track infrastructure on one- and two-element base taking into account the experience of railways in the EC countries and the current transport legislation were grounded. Practical value. The article proposes the one- and two-element models of calculating the fees (payments for the TIF use, accounting the applicable requirements of European transport legislation, which provides the expense compensation and income formation, sufficient for economic incentives of the efficient operation of the TIE of Ukrainian railway transport.
Practical model for the calculation of multiply scattered lidar returns
International Nuclear Information System (INIS)
Eloranta, E.W.
1998-01-01
An equation to predict the intensity of the multiply scattered lidar return is presented. Both the scattering cross section and the scattering phase function can be specified as a function of range. This equation applies when the cloud particles are larger than the lidar wavelength. This approximation considers photon trajectories with multiple small-angle forward-scattering events and one large-angle scattering that directs the photon back toward the receiver. Comparisons with Monte Carlo simulations, exact double-scatter calculations, and lidar data demonstrate that this model provides accurate results. copyright 1998 Optical Society of America
The calculation of exchange forces: General results and specific models
International Nuclear Information System (INIS)
Scott, T.C.; Babb, J.F.; Dalgarno, A.; Morgan, J.D. III
1993-01-01
In order to clarify questions about the calculation of the exchange energy of a homonuclear molecular ion, an analysis is carried out of a model problem consisting of the one-dimensional limit of H 2 + . It is demonstrated that the use of the infinite polarization expansion for the localized wave function in the Holstein--Herring formula yields an approximate exchange energy which at large internuclear distances R has the correct leading behavior to O(e -R ) and is close to but not equal to the exact exchange energy. The extension to the n-dimensional double-well problem is presented
Modeling Dynamic Objects in Monte Carlo Particle Transport Calculations
International Nuclear Information System (INIS)
Yegin, G.
2008-01-01
In this study, the Multi-Geometry geometry modeling technique was improved in order to handle moving objects in a Monte Carlo particle transport calculation. In the Multi-Geometry technique, the geometry is a superposition of objects not surfaces. By using this feature, we developed a new algorithm which allows a user to make enable or disable geometry elements during particle transport. A disabled object can be ignored at a certain stage of a calculation and switching among identical copies of the same object located adjacent poins during a particle simulation corresponds to the movement of that object in space. We called this powerfull feature as Dynamic Multi-Geometry technique (DMG) which is used for the first time in Brachy Dose Monte Carlo code to simulate HDR brachytherapy treatment systems. Our results showed that having disabled objects in a geometry does not effect calculated dose values. This technique is also suitable to be used in other areas such as IMRT treatment planning systems
International Nuclear Information System (INIS)
Fitzgerald, C.L.; Vaughen, V.C.A.; Lamb, C.E.
1977-07-01
Experiments using High-Temperature Gas-Cooled Reactor (HTGR) fuel material, TRISO-coated (2.75 Th/U)C 2 --TRISO-coated ThC 2 and TRISO-coated UO 2 --BISO-coated ThO 2 , were performed in Building 4507 (the High-Level Chemical Development Facility) to determine the inventory and transport behavior of fission products and heavy metals from a grind-burn-leach process flowsheet. In addition, values calculated by the ORNL Isotope Generation and Depletion Code (ORIGEN, a computer program used for predicting quantities of activation products, actinides, and fission products from irradiation data and nuclear data libraries) are compared with values derived by chemical analyses (CA) and those measured by a gamma-scan nondestructive analytical (NDA) technique. Reasonable agreement was obtained between ORIGEN and NDA results for one of the tests, but the values obtained by chemical analysis were lower than either of the two other sets of values. With the exception of 234 U, isotopic uranium values determined by chemical analysis (mass spectrometry) agreed within 15 percent of the ORIGEN prediction
Determination of appropriate models and parameters for premixing calculations
Energy Technology Data Exchange (ETDEWEB)
Park, Ik-Kyu; Kim, Jong-Hwan; Min, Beong-Tae; Hong, Seong-Wan
2008-03-15
The purpose of the present work is to use experiments that have been performed at Forschungszentrum Karlsruhe during about the last ten years for determining the most appropriate models and parameters for premixing calculations. The results of a QUEOS experiment are used to fix the parameters concerning heat transfer. The QUEOS experiments are especially suited for this purpose as they have been performed with small hot solid spheres. Therefore the area of heat exchange is known. With the heat transfer parameters fixed in this way, a PREMIX experiment is recalculated. These experiments have been performed with molten alumina (Al{sub 2}O{sub 3}) as a simulant of corium. Its initial temperature is 2600 K. With these experiments the models and parameters for jet and drop break-up are tested.
Determination of appropriate models and parameters for premixing calculations
International Nuclear Information System (INIS)
Park, Ik-Kyu; Kim, Jong-Hwan; Min, Beong-Tae; Hong, Seong-Wan
2008-03-01
The purpose of the present work is to use experiments that have been performed at Forschungszentrum Karlsruhe during about the last ten years for determining the most appropriate models and parameters for premixing calculations. The results of a QUEOS experiment are used to fix the parameters concerning heat transfer. The QUEOS experiments are especially suited for this purpose as they have been performed with small hot solid spheres. Therefore the area of heat exchange is known. With the heat transfer parameters fixed in this way, a PREMIX experiment is recalculated. These experiments have been performed with molten alumina (Al 2 O 3 ) as a simulant of corium. Its initial temperature is 2600 K. With these experiments the models and parameters for jet and drop break-up are tested
Calculating excess lifetime risk in relative risk models
International Nuclear Information System (INIS)
Vaeth, M.; Pierce, D.A.
1990-01-01
When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate
Recent Developments in No-Core Shell-Model Calculations
International Nuclear Information System (INIS)
Navratil, P.; Quaglioni, S.; Stetcu, I.; Barrett, B.R.
2009-01-01
We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this aproach, we start from realistic two-nucleon or two- plus three-nucleon interactions. Many-body calculations are performed using a finite harmonic-oscillator (HO) basis. To facilitate convergence for realistic inter-nucleon interactions that generate strong short-range correlations, we derive effective interactions by unitary transformations that are tailored to the HO basis truncation. For soft realistic interactions this might not be necessary. If that is the case, the NCSM calculations are variational. In either case, the ab initio NCSM preserves translational invariance of the nuclear many-body problem. In this review, we, in particular, highlight results obtained with the chiral two- plus three-nucleon interactions. We discuss efforts to extend the applicability of the NCSM to heavier nuclei and larger model spaces using importance-truncation schemes and/or use of effective interactions with a core. We outline an extension of the ab initio NCSM to the description of nuclear reactions by the resonating group method technique. A future direction of the approach, the ab initio NCSM with continuum, which will provide a complete description of nuclei as open systems with coupling of bound and continuum states is given in the concluding part of the review.
Recent Developments in No-Core Shell-Model Calculations
Energy Technology Data Exchange (ETDEWEB)
Navratil, P; Quaglioni, S; Stetcu, I; Barrett, B R
2009-03-20
We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this aproach, we start from realistic two-nucleon or two- plus three-nucleon interactions. Many-body calculations are performed using a finite harmonic-oscillator (HO) basis. To facilitate convergence for realistic inter-nucleon interactions that generate strong short-range correlations, we derive effective interactions by unitary transformations that are tailored to the HO basis truncation. For soft realistic interactions this might not be necessary. If that is the case, the NCSM calculations are variational. In either case, the ab initio NCSM preserves translational invariance of the nuclear many-body problem. In this review, we, in particular, highlight results obtained with the chiral two- plus three-nucleon interactions. We discuss efforts to extend the applicability of the NCSM to heavier nuclei and larger model spaces using importance-truncation schemes and/or use of effective interactions with a core. We outline an extension of the ab initio NCSM to the description of nuclear reactions by the resonating group method technique. A future direction of the approach, the ab initio NCSM with continuum, which will provide a complete description of nuclei as open systems with coupling of bound and continuum states is given in the concluding part of the review.
Modeling and calculation of open carbon dioxide refrigeration system
International Nuclear Information System (INIS)
Cai, Yufei; Zhu, Chunling; Jiang, Yanlong; Shi, Hong
2015-01-01
Highlights: • A model of open refrigeration system is developed. • The state of CO 2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO 2 has little relation to the state of CO 2 . • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration
Computational models for probabilistic neutronic calculation in TADSEA
International Nuclear Information System (INIS)
Garcia, Jesus A.R.; Curbelo, Jesus P.; Hernandez, Carlos R.G.; Oliva, Amaury M.; Lira, Carlos A.B.O.
2013-01-01
The Very High Temperature Reactor is one of the main candidates for the next generation of nuclear power plants. In pebble bed reactors, the fuel is contained within graphite pebbles in the form of TRISO particles, which form a randomly packed bed inside a graphite-walled cylindrical cavity. In previous studies, the conceptual design of a Transmutation Advanced Device for Sustainable Energy Applications (TADSEA) has been made. The TADSEA is a pebble-bed ADS cooled by helium and moderated by graphite. In order to simulate the TADSEA correctly, the double heterogeneity of the system must be considered. It consists on randomly located pebbles into the core and randomly located TRISO particles into the fuel pebbles. These features are often neglected due to the difficulty to model with MCNP code. The main reason is that there is a limited number of cells and surfaces to be defined. In this paper a computational tool, which allows to get a new geometrical model for fuel pebble to neutronic calculation with MCNPX, was presented. The heterogeneity of system is considered, and also the randomly located TRISO particles inside the pebble. There are also compared several neutronic computational models for TADSEA's fuel pebbles in order to study heterogeneity effects. On the other hand the boundary effect given by the intersection between the pebble surface and the TRISO particles could be significative in the multiplicative properties. A model to study this e ect is also presented. (author)
Volume-based geometric modeling for radiation transport calculations
International Nuclear Information System (INIS)
Li, Z.; Williamson, J.F.
1992-01-01
Accurate theoretical characterization of radiation fields is a valuable tool in the design of complex systems, such as linac heads and intracavitary applicators, and for generation of basic dose calculation data that is inaccessible to experimental measurement. Both Monte Carlo and deterministic solutions to such problems require a system for accurately modeling complex 3-D geometries that supports ray tracing, point and segment classification, and 2-D graphical representation. Previous combinatorial approaches to solid modeling, which involve describing complex structures as set-theoretic combinations of simple objects, are limited in their ease of use and place unrealistic constraints on the geometric relations between objects such as excluding common boundaries. A new approach to volume-based solid modeling has been developed which is based upon topologically consistent definitions of boundary, interior, and exterior of a region. From these definitions, FORTRAN union, intersection, and difference routines have been developed that allow involuted and deeply nested structures to be described as set-theoretic combinations of ellipsoids, elliptic cylinders, prisms, cones, and planes that accommodate shared boundaries. Line segments between adjacent intersections on a trajectory are assigned to the appropriate region by a novel sorting algorithm that generalizes upon Siddon's approach. Two 2-D graphic display tools are developed to help the debugging of a given geometric model. In this paper, the mathematical basis of our system is described, it is contrasted to other approaches, and examples are discussed
Development of nuclear models for higher energy calculations
International Nuclear Information System (INIS)
Bozoian, M.; Siciliano, E.R.; Smith, R.D.
1988-01-01
Two nuclear models for higher energy calculations have been developed in the regions of high and low energy transfer, respectively. In the former, a relativistic hybrid-type preequilibrium model is compared with data ranging from 60 to 800 MeV. Also, the GNASH exciton preequilibrium-model code with higher energy improvements is compared with data at 200 and 318 MeV. In the region of low energy transfer, nucleon-nucleus scattering is predominately a direct reaction involving quasi-elastic collisions with one or more target nucleons. We discuss various aspects of quasi-elastic scattering which are important in understanding features of cross sections and spin observables. These include (1) contributions from multi-step processes; (2) damping of the continuum response from 2p-2h excitations; (3) the ''optimal'' choice of frame in which to evaluate the nucleon-nucleon amplitudes; and (4) the effect of optical and spin-orbit distortions, which are included in a model based on the RPA the DWIA and the eikonal approximation. 33 refs., 15 figs
Updated thermal model using simplified short-wave radiosity calculations
International Nuclear Information System (INIS)
Smith, J.A.; Goltz, S.M.
1994-01-01
An extension to a forest canopy thermal radiance model is described that computes the short-wave energy flux absorbed within the canopy by solving simplified radiosity equations describing flux transfers between canopy ensemble classes partitioned by vegetation layer and leaf slope. Integrated short-wave reflectance and transmittance-factors obtained from measured leaf optical properties were found to be nearly equal for the canopy studied. Short-wave view factor matrices were approximated by combining the average leaf scattering coefficient with the long-wave view factor matrices already incorporated in the model. Both the updated and original models were evaluated for a dense spruce fir forest study site in Central Maine. Canopy short-wave absorption coefficients estimated from detailed Monte Carlo ray tracing calculations were 0.60, 0.04, and 0.03 for the top, middle, and lower canopy layers corresponding to leaf area indices of 4.0, 1.05, and 0.25. The simplified radiosity technique yielded analogous absorption values of 0.55, 0.03, and 0.01. The resulting root mean square error in modeled versus measured canopy temperatures for all layers was less than 1°C with either technique. Maximum error in predicted temperature using the simplified radiosity technique was approximately 2°C during peak solar heating. (author)
Updated thermal model using simplified short-wave radiosity calculations
Energy Technology Data Exchange (ETDEWEB)
Smith, J. A.; Goltz, S. M.
1994-02-15
An extension to a forest canopy thermal radiance model is described that computes the short-wave energy flux absorbed within the canopy by solving simplified radiosity equations describing flux transfers between canopy ensemble classes partitioned by vegetation layer and leaf slope. Integrated short-wave reflectance and transmittance-factors obtained from measured leaf optical properties were found to be nearly equal for the canopy studied. Short-wave view factor matrices were approximated by combining the average leaf scattering coefficient with the long-wave view factor matrices already incorporated in the model. Both the updated and original models were evaluated for a dense spruce fir forest study site in Central Maine. Canopy short-wave absorption coefficients estimated from detailed Monte Carlo ray tracing calculations were 0.60, 0.04, and 0.03 for the top, middle, and lower canopy layers corresponding to leaf area indices of 4.0, 1.05, and 0.25. The simplified radiosity technique yielded analogous absorption values of 0.55, 0.03, and 0.01. The resulting root mean square error in modeled versus measured canopy temperatures for all layers was less than 1°C with either technique. Maximum error in predicted temperature using the simplified radiosity technique was approximately 2°C during peak solar heating. (author)
Studies on the behaviour of heat transfer flowsheets with fluids
International Nuclear Information System (INIS)
Munser, H.
1989-01-01
A model is presented which provides a dynamic description of plant components in the secondary coolant circuit of WWER-1000-type nuclear power stations. These components employ combined heat exchangers as their main constituents which themselves are composed of simple water-water and steam-water heat exchangers. The simple heat exchangers are described by means of linearized sets of partial differential equations which can be solved by Laplace transformation. The code system DAW has been established for dynamic modulation of plant components. (author)
Energy Technology Data Exchange (ETDEWEB)
Kneur, J.L
2006-06-15
This document is divided into 2 parts. The first part describes a particular re-summation technique of perturbative series that can give a non-perturbative results in some cases. We detail some applications in field theory and in condensed matter like the calculation of the effective temperature of Bose-Einstein condensates. The second part deals with the minimal supersymmetric standard model. We present an accurate calculation of the mass spectrum of supersymmetric particles, a calculation of the relic density of supersymmetric black matter, and the constraints that we can infer from models.
Cluster model calculations of the solid state materials electron structure
International Nuclear Information System (INIS)
Pelikan, P.; Biskupic, S.; Banacky, P.; Zajac, A.; Svrcek, A.; Noga, J.
1997-01-01
Materials of the general composition ACuO 2 are the parent compounds of so called infinite layer superconductors. In the paper presented the electron structure of the compounds CaCuO 2 , SrCuO2, Ca 0.86 Sr 0.14 CuO2 and Ca 0.26 Sr 0.74 CuO 2 were calculated. The cluster models consisting of 192 atoms were computed using quasi relativistic version of semiempirical INDO method. The obtained results indicate the strong ionicity of Ca/Sr-O bonds and high covalency of Cu-bonds. The width of energy gap at the Fermi level increases as follows: Ca 0.26 Sr 0.74 CuO 2 0.86 Sr 0.14 CuO2 2 . This order correlates with the fact that materials of the composition Ca x Sr 1-x CuO 2 have have the high temperatures of the superconductive transition (up to 110 K). Materials partially substituted by Sr 2+ have also the higher density of states in the close vicinity at the Fermi level that ai the additional condition for the possibility of superconductive transition. It was calculated the strong influence of the vibration motions to the energy gap at the Fermi level. (authors). 1 tabs., 2 figs., 10 refs
Selection of models to calculate the LLW source term
International Nuclear Information System (INIS)
Sullivan, T.M.
1991-10-01
Performance assessment of a LLW disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). In turn, many of these physical processes are influenced by the design of the disposal facility (e.g., infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This document provides a brief overview of disposal practices and reviews existing source term models as background for selecting appropriate models for estimating the source term. The selection rationale and the mathematical details of the models are presented. Finally, guidance is presented for combining the inventory data with appropriate mechanisms describing release from the disposal facility. 44 refs., 6 figs., 1 tab
Calculational models of close-spaced thermionic converters
International Nuclear Information System (INIS)
McVey, J.B.
1983-01-01
Two new calculational models have been developed in conjunction with the SAVTEC experimental program. These models have been used to analyze data from experimental close-spaced converters, providing values for spacing, electrode work functions, and converter efficiency. They have also been used to make performance predictions for such converters over a wide range of conditions. Both models are intended for use in the collisionless (Knudsen) regime. They differ from each other in that the simpler one uses a Langmuir-type formulation which only considers electrons emitted from the emitter. This approach is implemented in the LVD (Langmuir Vacuum Diode) computer program, which has the virtue of being both simple and fast. The more complex model also includes both Saha-Langmuir emission of positive cesium ions from the emitter and collector back emission. Computer implementation is by the KMD1 (Knudsen Mode Diode) program. The KMD1 model derives the particle distribution functions from the Vlasov equation. From these the particle densities are found for various interelectrode motive shapes. Substituting the particle densities into Poisson's equation gives a second order differential equation for potential. This equation can be integrated once analytically. The second integration, which gives the interelectrode motive, is performed numerically by the KMD1 program. This is complicated by the fact that the integrand is often singular at one end point of the integration interval. The program performs a transformation on the integrand to make it finite over the entire interval. Once the motive has been computed, the output voltage, current density, power density, and efficiency are found. The program is presently unable to operate when the ion richness ratio β is between about .8 and 1.0, due to the occurrence of oscillatory motives
International Nuclear Information System (INIS)
Mueller, R.G.
1987-06-01
Due to the strong influence of vapour bubbles on the nuclear chain reaction, an exact calculation of neutron physics and thermal hydraulics in light water reactors requires consideration of subcooled boiling. To this purpose, in the present study a dynamic model is derived from the time-dependent conservation equations. It contains new methods for the time-dependent determination of evaporation and condensation heat flow and for the heat transfer coefficient in subcooled boiling. Furthermore, it enables the complete two-phase flow region to be treated in a consistent manner. The calculation model was verified using measured data of experiments covering a wide range of thermodynamic boundary conditions. In all cases very good agreement was reached. The results from the coupling of the new calculation model with a neutron kinetics program proved its suitability for the steady-state and transient calculation of reactor cores. (orig.) [de
The conceptual flowsheet of effluent treatment during preparing spherical fuel elements of HTR
Energy Technology Data Exchange (ETDEWEB)
Ying, Quan, E-mail: quanying@tsinghua.edu.cn; Xiao-tong, Chen; Bing, Liu; Gen-na, Fu; Yang, Wang; You-lin, Shao; Zhen-ming, Lu; Ya-ping, Tang; Chun-he, Tang
2014-05-01
High temperature gas-cooled reactor (HTR) is one of the advanced nuclear reactors owing to its inherent safety and broad applications. For HTR, one of the key components is the ceramic fuel element. During the preparation of spherical fuel elements, the radioactive effluent treatment is necessary. Referring to the current treatment technologies and methods, the conceptual flowsheet of low-level radioactive effluent treatment during preparing spherical fuel elements was established. According to the above treatment process, the uranium concentration was decreased from 200 mg/l to the level of discharged standard.
Characterization of Neptunium Oxide Generated Using the HB-Line Phase II Flowsheet
Energy Technology Data Exchange (ETDEWEB)
Duffey, J
2003-08-29
Approximately 98 grams of neptunium(IV) oxide (NpO{sub 2}) were produced at the Savannah River Technology Center (SRTC) for use in gas generation tests to support the neptunium stabilization program at the Savannah River Site (SRS). The NpO{sub 2} was produced according to the anticipated HB-Line flowsheet consisting of anion exchange, oxalate precipitation, filtration, and calcination. Characterization of the NpO{sub 2} product to be used in gas generation tests included bulk and tap density measurements, X-ray diffraction, particle size distribution, specific surface area measurements, and moisture analysis.
Calculating ε'/ε in the standard model
International Nuclear Information System (INIS)
Sharpe, S.R.
1988-01-01
The ingredients needed in order to calculate ε' and ε are described. Particular emphasis is given to the non-perturbative calculations of matrix elements by lattice methods. The status of the electromagnetic contribution to ε' is reviewed. 15 refs
Comparative analysis of calculation models of railway subgrade
Directory of Open Access Journals (Sweden)
I.O. Sviatko
2013-08-01
Full Text Available Purpose. In transport engineering structures design, the primary task is to determine the parameters of foundation soil and nuances of its work under loads. It is very important to determine the parameters of shear resistance and the parameters, determining the development of deep deformations in foundation soils, while calculating the soil subgrade - upper track structure interaction. Search for generalized numerical modeling methods of embankment foundation soil work that include not only the analysis of the foundation stress state but also of its deformed one. Methodology. The analysis of existing modern and classical methods of numerical simulation of soil samples under static load was made. Findings. According to traditional methods of analysis of ground masses work, limitation and the qualitative estimation of subgrade deformations is possible only indirectly, through the estimation of stress and comparison of received values with the boundary ones. Originality. A new computational model was proposed in which it will be applied not only classical approach analysis of the soil subgrade stress state, but deformed state will be also taken into account. Practical value. The analysis showed that for accurate analysis of ground masses work it is necessary to develop a generalized methodology for analyzing of the rolling stock - railway subgrade interaction, which will use not only the classical approach of analyzing the soil subgrade stress state, but also take into account its deformed one.
Accurate Holdup Calculations with Predictive Modeling & Data Integration
Energy Technology Data Exchange (ETDEWEB)
Azmy, Yousry [North Carolina State Univ., Raleigh, NC (United States). Dept. of Nuclear Engineering; Cacuci, Dan [Univ. of South Carolina, Columbia, SC (United States). Dept. of Mechanical Engineering
2017-04-03
In facilities that process special nuclear material (SNM) it is important to account accurately for the fissile material that enters and leaves the plant. Although there are many stages and processes through which materials must be traced and measured, the focus of this project is material that is “held-up” in equipment, pipes, and ducts during normal operation and that can accumulate over time into significant quantities. Accurately estimating the holdup is essential for proper SNM accounting (vis-à-vis nuclear non-proliferation), criticality and radiation safety, waste management, and efficient plant operation. Usually it is not possible to directly measure the holdup quantity and location, so these must be inferred from measured radiation fields, primarily gamma and less frequently neutrons. Current methods to quantify holdup, i.e. Generalized Geometry Holdup (GGH), primarily rely on simple source configurations and crude radiation transport models aided by ad hoc correction factors. This project seeks an alternate method of performing measurement-based holdup calculations using a predictive model that employs state-of-the-art radiation transport codes capable of accurately simulating such situations. Inverse and data assimilation methods use the forward transport model to search for a source configuration that best matches the measured data and simultaneously provide an estimate of the level of confidence in the correctness of such configuration. In this work the holdup problem is re-interpreted as an inverse problem that is under-determined, hence may permit multiple solutions. A probabilistic approach is applied to solving the resulting inverse problem. This approach rates possible solutions according to their plausibility given the measurements and initial information. This is accomplished through the use of Bayes’ Theorem that resolves the issue of multiple solutions by giving an estimate of the probability of observing each possible solution. To use
Glass operational file. Operational models and integration calculations
International Nuclear Information System (INIS)
Ribet, I.
2004-01-01
This document presents the operational choices of dominating phenomena, hypotheses, equations and numerical data of the parameters used in the two operational models elaborated for the calculation of the glass source terms with respect to the waste packages considered: existing packages (R7T7, AVM and CEA glasses) and future ones (UOX2, UOX3, UMo, others). The overall operational choices are justified and demonstrated and a critical analysis of the approach is systematically proposed. The use of the operational model (OPM) V 0 → V r , realistic, conservative and robust, is recommended for glasses with a high thermal and radioactive load, which represent the main part of the vitrified wastes. The OPM V 0 S, much more overestimating but faster to parameterize, can be used for the long-term behaviour forecasting of glasses with low thermal and radioactive load, considering today's lack of knowledge for the parameterization of a V 0 → V r type OPM. Efficiency estimations have been made for R7T7 glasses (OPM V 0 → V r ) and AVM glasses (OPM V 0 S), which correspond to more than 99.9% of the vitrified waste packages activity. The very contrasted results obtained, illustrate the importance of the choice of operational models: in conditions representative of a geologic disposal, the estimation of R7T7-type package lifetime exceeds several hundred thousands years. Even if the estimated lifetime of AVM packages is much shorter (because of the overestimating character of the OPM V 0 S), the release potential radiotoxicity is of the same order as the one of R7T7 packages. (J.S.)
Groundwater flow modelling under ice sheet conditions. Scoping calculations
Energy Technology Data Exchange (ETDEWEB)
Jaquet, O.; Namar, R. (In2Earth Modelling Ltd (Switzerland)); Jansson, P. (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden))
2010-10-15
The potential impact of long-term climate changes has to be evaluated with respect to repository performance and safety. In particular, glacial periods of advancing and retreating ice sheet and prolonged permafrost conditions are likely to occur over the repository site. The growth and decay of ice sheets and the associated distribution of permafrost will affect the groundwater flow field and its composition. As large changes may take place, the understanding of groundwater flow patterns in connection to glaciations is an important issue for the geological disposal at long term. During a glacial period, the performance of the repository could be weakened by some of the following conditions and associated processes: - Maximum pressure at repository depth (canister failure). - Maximum permafrost depth (canister failure, buffer function). - Concentration of groundwater oxygen (canister corrosion). - Groundwater salinity (buffer stability). - Glacially induced earthquakes (canister failure). Therefore, the GAP project aims at understanding key hydrogeological issues as well as answering specific questions: - Regional groundwater flow system under ice sheet conditions. - Flow and infiltration conditions at the ice sheet bed. - Penetration depth of glacial meltwater into the bedrock. - Water chemical composition at repository depth in presence of glacial effects. - Role of the taliks, located in front of the ice sheet, likely to act as potential discharge zones of deep groundwater flow. - Influence of permafrost distribution on the groundwater flow system in relation to build-up and thawing periods. - Consequences of glacially induced earthquakes on the groundwater flow system. Some answers will be provided by the field data and investigations; the integration of the information and the dynamic characterisation of the key processes will be obtained using numerical modelling. Since most of the data are not yet available, some scoping calculations are performed using the
Groundwater flow modelling under ice sheet conditions. Scoping calculations
International Nuclear Information System (INIS)
Jaquet, O.; Namar, R.; Jansson, P.
2010-10-01
The potential impact of long-term climate changes has to be evaluated with respect to repository performance and safety. In particular, glacial periods of advancing and retreating ice sheet and prolonged permafrost conditions are likely to occur over the repository site. The growth and decay of ice sheets and the associated distribution of permafrost will affect the groundwater flow field and its composition. As large changes may take place, the understanding of groundwater flow patterns in connection to glaciations is an important issue for the geological disposal at long term. During a glacial period, the performance of the repository could be weakened by some of the following conditions and associated processes: - Maximum pressure at repository depth (canister failure). - Maximum permafrost depth (canister failure, buffer function). - Concentration of groundwater oxygen (canister corrosion). - Groundwater salinity (buffer stability). - Glacially induced earthquakes (canister failure). Therefore, the GAP project aims at understanding key hydrogeological issues as well as answering specific questions: - Regional groundwater flow system under ice sheet conditions. - Flow and infiltration conditions at the ice sheet bed. - Penetration depth of glacial meltwater into the bedrock. - Water chemical composition at repository depth in presence of glacial effects. - Role of the taliks, located in front of the ice sheet, likely to act as potential discharge zones of deep groundwater flow. - Influence of permafrost distribution on the groundwater flow system in relation to build-up and thawing periods. - Consequences of glacially induced earthquakes on the groundwater flow system. Some answers will be provided by the field data and investigations; the integration of the information and the dynamic characterisation of the key processes will be obtained using numerical modelling. Since most of the data are not yet available, some scoping calculations are performed using the
Flowsheet Validation For The Permanganate Digestion Of REILLEX(trademark) HPQ Anion Resin
International Nuclear Information System (INIS)
Kyser, E.
2009-01-01
The flowsheet for the digestion of Reillex(trademark) HPQ was validated both under the traditional alkaline conditions and under strongly acidic conditions. Due to difficulty in performing a pH adjustment in the large tank where this flowsheet must be performed, the recommended digestion conditions were changed from pH 8-10 to 8 M HNO 3 . Thus, no pH adjustment of the solution is required prior to performing the permanganate addition and digestion and the need to sample the digestion tank to confirm appropriate pH range for digestion may be avoided. Neutralization of the acidic digestion solution will be performed after completion of the resin digestion cycle. The amount of permanganate required for this type of resin (Reillex(trademark) HPQ) was increased from 1 kg/L resin to 4 kg/L resin to reduce the amount of residual resin solids to a minimal amount ( 2 ) solids (1.71 kg/L resin) and involves the generation of a significant liquid volume due to the low solubility of permanganate. However, since only two batches of resin (40 L each) are expected to be digested, the total waste generated is limited.
Actual Waste Demonstration of the Nitric-Glycolic Flowsheet for Sludge Batch 9 Qualification
Energy Technology Data Exchange (ETDEWEB)
Newell, J. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Martino, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reboul, S. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coleman, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Johnson, F. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-09-01
For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) performs qualification testing to demonstrate that the sludge batch is processable. Testing performed by the Savannah River National Laboratory has shown glycolic acid to be effective in replacing the function of formic acid in the DWPF chemical process. The nitric-glycolic flowsheet reduces mercury, significantly lowers the catalytic generation of hydrogen and ammonia which could allow purge reduction in the Sludge Receipt and Adjustment Tank (SRAT), stabilizes the pH and chemistry in the SRAT and the Slurry Mix Evaporator (SME), allows for effective rheology adjustment, and is favorable with respect to melter flammability. In order to implement the new flowsheet, SRAT and SME cycles, designated SC-18, were performed using a Sludge Batch (SB) 9 slurry blended from SB8 Tank 40H and Tank 51H samples. The SRAT cycle involved adding nitric and glycolic acids to the sludge, refluxing to steam strip mercury, and dewatering to a targeted solids concentration. Data collected during the SRAT cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. The SME cycle demonstrated the addition of glass frit and the replication of six canister decontamination additions. The demonstration concluded with dewatering to a targeted solids concentration. Data collected during the SME cycle included offgas analyses, process temperatures, heat transfer, and pH measurements. Slurry and condensate samples were collected for subsequent analysis
Simplified nuclear fuel reprocessing flowsheet: a single-cycle Purex process
International Nuclear Information System (INIS)
Montuir, M.; Dinh, B.; Baron, P.
2004-01-01
A simplified flowsheet with only one purification cycle instead of three is proposed for reprocessing spent nuclear fuel using the Purex process. A single-cycle flowsheet minimizes the process equipment required, the number of control points before transfer between process units, and the solvent and effluent quantities. For the uranium stream, an alpha barrier is used to strip any residual contaminants (Np, Th, Pu) from the uranium-loaded solvent. This additional step eliminates the need for a second uranium cycle. For the plutonium stream, an additional βγ co-decontamination step and a higher plutonium concentration are required before the oxalate conversion step; a plutonium 'half-cycle' is added downstream. The unloaded solvent from this half-cycle is returned to the selective plutonium stripping step, allowing significant plutonium half-cycle losses. It should be possible to reduce the number of stages in the half-cycle extraction step by recycling the raffinate to the upstream separation process. (authors)
Hydrogen generation in SRAT with nitric acid and late washing flowsheets
International Nuclear Information System (INIS)
Hsu, C.W.
1992-01-01
Melter feed preparation processes, incorporating a final wash of the precipitate slurry feed to Defense Waste Processing Facility (DWPF) and a partial substitution of the SRAT formic acid requirement with nitric acid, should not produce peak hydrogen generation rates during Cold Chemical Runs (CCR's) and radioactive operation greater than their current, respective hydrogen design bases of 0.024 lb/hr and 1.5 lb/hr. A single SRAT bench-scale process simulation for CCR-s produced a DWPF equivalent peak hydrogen generation rate of 0.004 lb/hr. During radioactive operation, the peak hydrogen generation rate will be dependent on the extent DWPF deviates from the nominal precipitate hydrolysis and melter feed preparation process operating parameters. Two actual radioactive sludges were treated according to the new flowsheets. The peak hydrogen evolution rates were equivalent to 0.038 and 0.20 lb/hr (DWPF scale) respectively. Compared to the formic acid -- HAN hydrolysis flowsheets, these peak rates were reduced by a factor of 2.5 and 3.4 for Tank 15 and Tank 11 sludges, respectively
Calculation of real optical model potential for heavy ions in the framework of the folding model
International Nuclear Information System (INIS)
Goncharov, S.A.; Timofeyuk, N.K.; Kazacha, G.S.
1987-01-01
The code for calculation of a real optical model potential in the framework of the folding model is realized. The program of numerical Fourier-Bessel transformation based on Filon's integration rule is used. The accuracy of numerical calculations is ∼ 10 -4 for a distance interval up to a bout (2.5-3) times the size of nuclei. The potentials are calculated for interactions of 3,4 He with nuclei from 9 Be to 27 Al with different effective NN-interactions and densities obtained from electron scattering data. Calculated potentials are similar to phenomenological potentials in Woods-Saxon form. With calculated potentials the available elastic scattering data for the considered nuclei in the energy interval 18-56 MeV are analysed. The needed renormalizations for folding potentials are < or approx. 20%
Models for calculation of dissociation energies of homonuclear diatomic molecules
International Nuclear Information System (INIS)
Brewer, L.; Winn, J.S.
1979-08-01
The variation of known dissociation energies of the transition metal diatomics across the Periodic Table is rather irregular like the bulk sublimation enthalpy, suggesting that the valence-bond model for bulk metallic systems might be applicable to the gaseous diatomic molecules and the various intermediate clusters. Available dissociation energies were converted to valence-state bonding energies considering various degrees of promotion to optimize the bonding. The degree of promotion of electrons to increase the number of bonding electrons is smaller than for the bulk, but the trends in bonding energy parallel the behavior found for the bulk metals. Thus using the established trends in bonding energies for the bulk elements, it was possible to calculate all unknown dissociation energies to provide a complete table of dissociation energies for all M 2 molecules from H 2 to Lr 2 . For solids such as Mg, Al, Si and most of the transition metals, large promotion energies are offset by strong bonding between the valence state atoms. The main question is whether bonding in the diatomics is adequate to sustain extensive promotion. The most extreme example for which a considerable difference would be expected between the bulk and the diatomics would be that of the Group IIA and IIB metals. The first section of this paper which deals with the alkaline earths Mg and Ca demonstrates a significant influence of the excited valence state even for these elements. The next section then expands the treatment to transition metals
The COST model for calculation of forest operations costs
Ackerman, P.; Belbo, H.; Eliasson, L.; Jong, de J.J.; Lazdins, A.; Lyons, J.
2014-01-01
Since the late nineteenth century when high-cost equipment was introduced into forestry there has been a need to calculate the cost of this equipment in more detail with respect to, for example, cost of ownership, cost per hour of production, and cost per production unit. Machine cost calculations
Improvements in the model of neutron calculations for research reactors
International Nuclear Information System (INIS)
Calzetta, Osvaldo; Leszczynski, Francisco
1987-01-01
Within the research program in the field of neutron physics calculations being carried out in the Nuclear Engineering Division at the Centro Atomico Bariloche, the errors which due to some typical approximations appear in the final results are researched. For research MTR type reactors, two approximations, for high and low enrichment are investigated: the treatment of the geometry and the method of few-group cell cross-sections calculation, particularly in the resonance energy region. Commonly, the cell constants used for the entire reactor calculation are obtained making an homogenization of the full fuel elements, by one-dimensional calculations. An improvement is made that explicitly includes the fuel element frames in the core calculation geometry. Besides, a detailed treatment-in energy and space- is used to find the resonance few-group cross sections, and a comparison of the results with detailed and approximated calculations is made. The least number and the best mesh of energy groups needed for cell calculations is fixed too. (Author) [es
International Nuclear Information System (INIS)
Ainsworth, T.L.
1983-01-01
The Δ(1232) plays an important role in determining the properties of nuclear and neutron matter. The effects of the Δ resonance are incorporated explicitly by using a coupled channel formalism. A method for constraining a lowest order variational calculation, appropriate when nucleon internal degrees of freedom are made explicity, is presented. Different N-N potentials were calculated and fit to phase shift data and deuteron properties. The potentials were constructed to test the relative importance of the Δ resonance on nuclear properties. The symmetry energy and incompressibility of nuclear matter are generally reproduced by this calculation. Neutron matter results lead to appealing neutron star models. Fermi liquid parameters for 3 He are calculated with a model that includes both direct and induced terms. A convenient form of the direct interaction is obtained in terms of the parameters. The form of the direct interaction ensures that the forward scattering sum rule (Pauli principle) is obeyed. The parameters are adjusted to fit the experimentally determined F 0 /sup s/, F 0 /sup a/, and F 1 /sup s/ Landau parameters. Higher order Landau parameters are calculated by the self-consistent solution of the equations; comparison to experiment is good. The model also leads to a preferred value for the effective mass of 3 He. Of the three parameters only one shows any dependence on pressure. An exact sum rule is derived relating this parameter to a specific summation of Landau parameters
International Nuclear Information System (INIS)
Law, J.D.; Wood, D.J.; Todd, T.A.
1999-01-01
Laboratory experimentation has indicated that the SREX process is effective for partitioning 90 Sr from acidic radioactive waste solutions located at the Idaho Nuclear Technology and Engineering Center. These laboratory results were used to develop a flowsheet for countercurrent testing of the SREX process with dissolved pilot plant calcine. Testing was performed using 24 stages of 2-cm diameter centrifugal contactors which are installed in the Remote Analytical Laboratory hot cell. Dissolved Run No.64 pilot plant calcine spiked with 85 Sr was used as feed solution for the testing. The flowsheet tested consisted of an extraction section (0.15 M 4prime,4prime(5prime)-di-(tert-butylcyclohexo)-18-crown-6 and 1.5 M TBP in Isopar-L.), a 1.0 M NaNO 3 scrub section to remove extracted K from the SREX solvent, a 0.01 M HNO 3 strip section for the removal of Sr from the SREX solvent, a 0.25 M Na2CO 3 wash section to remove degradation products from the solvent, and a 0.1 M HNO 3 rinse section. The behavior of 85 Sr, Na, K, Al, B, Ca, Cr, Fe, Ni, and Zr was evaluated. The described flowsheet successfully extracted 85 Sr from the dissolved pilot plant calcine with a removal efficiency of 99.6%. Distribution coefficients for 85 Sr ranged from 3.6 to 4.5 in the extraction section. With these distribution coefficients a removal efficiency of approximately >99.99% was expected. It was determined that the lower than expected removal efficiency can be attributed to a stage efficiency of only 60% in the extraction section. Extracted K was effectively scrubbed from the SREX solvent with the 1.0 M NaNO 3 resulting in only 6.4% of the K in the HLW strip product. Sodium was not extracted from the dissolved calcine by the SREX solvent; however, the use of a 1.0 M NaNO 3 scrub solution resulted in a Na concentration of 70 mg/L (12.3% of the feed concentration) in the HLW strip product. Al, B, Ca, Cr, Fe, Ni, and Zr were determined to be essentially inextractable
Energy Technology Data Exchange (ETDEWEB)
Mallik, G K; Malav, R K; Karande, A P; Bhargava, V K; Kamath, H S [Advanced Fuel Fabrication Facility, Bhabha Atomic Research Centre, Tarapur (India)
1999-01-01
A simple, short and efficient scrap, recycling flow-sheet, which is exclusively based on microwave heating techniques and, includes both dry and wet routes, for (U,Pu)O{sub 2} fuel scrap recycling has been developed and evaluated. (author) 6 refs., 1 tab.
International Nuclear Information System (INIS)
Barnes, C.M.; Lauerhass, L.; Olson, A.L.; Taylor, D.D.; Valentine, J.H.; Lockie, K.A.
2002-01-01
The High-Level Waste (HLW) Program at the Idaho National Engineering and Environmental Laboratory (INEEL) must implement technologies and processes to treat and qualify radioactive wastes located at the Idaho Nuclear Technology and Engineering Center (INTEC) for permanent disposal. This paper describes the approach and accomplishments to date for completing development of a baseline vitrification treatment flowsheet for sodium-bearing waste (SBW), including development of a relational database used to manage the associated process assumptions. A process baseline has been developed that includes process requirements, basis and assumptions, process flow diagrams, a process description, and a mass balance. In the absence of actual process or experimental results, mass and energy balance data for certain process steps are based on assumptions. Identification, documentation, validation, and overall management of the flowsheet assumptions are critical to ensuring an integrated, focused program. The INEEL HLW Program initially used a roadmapping methodology, developed through the INEEL Environmental Management Integration Program, to identify, document, and assess the uncertainty and risk associated with the SBW flowsheet process assumptions. However, the mass balance assumptions, process configuration and requirements should be accessible to all program participants. This need resulted in the creation of a relational database that provides formal documentation and tracking of the programmatic uncertainties related to the SBW flowsheet
International Nuclear Information System (INIS)
Lazarev, L.N.; Galkin, B.Ya; Lyubtsev, R.I.; Romanovskii, V.N.; Velikhov, E.P.
1981-01-01
The fuel reprocessing pilot plants for high active materials would permit the study and development or particular processing steps and flowsheet variations; in some cases, these experimental installations realize on a small scale practically all technological chains of large reprocessing plants. Such a fuel reprocessing pilot plant with capacity of 3 kg U/d has been built at V. G. Khlopin Radium Institute. The pilot plant is installed in the hot cell of radiochemical compartment, and is composed of the equipments for fuel element cutting and dissolving, the preparation of feed solution (clarification, correction), extraction reprocessing and the production of uranium, plutonium and neptunium concentrates, the complex processing of liquid and solid wastes and a special unit for gas purification and analysis. In the last few years, a series of experiments have been carried out on the reprocessing of spent VVER fuel. (J.P.N.)
Comparison of standard fast reactor calculations (Baker model)
Energy Technology Data Exchange (ETDEWEB)
Voropaev, A I; Van' kov, A A; Tsybulya, A M
1978-12-01
Compared are standard fast reactor calculations performed at different laboratories using several nuclear data files: BNAB-70 and OSKAR-75 (the USSR), CARNAVAL-4 (France), FD-5 (Great Britain), KFK-INR (West Germany), ENDF/B4 (the USA). Three fuel compositions were chosen: (1) /sup 239/Pu and /sup 238/U; (2) /sup 239/Pu, /sup 238/U and fission products; (3) /sup 239/Pu, /sup 240/Pu, /sup 238/U and fission products. Medium temperature was 300K. The calculations have been conducted in the diffusion approximation. Data on critical masses and breeding ratios are tabulated. Discrepancies in the calculations of all the characteristics are small since all the countries possess practically the same nuclear data files.
Calculational advance in the modeling of fuel-coolant interactions
International Nuclear Information System (INIS)
Bohl, W.R.
1982-01-01
A new technique is applied to numerically simulate a fuel-coolant interaction. The technique is based on the ability to calculate separate space- and time-dependent velocities for each of the participating components. In the limiting case of a vapor explosion, this framework allows calculation of the pre-mixing phase of film boiling and interpenetration of the working fluid by hot liquid, which is required for extrapolating from experiments to a reactor hypothetical accident. Qualitative results are compared favorably to published experimental data where an iron-alumina mixture was poured into water. Differing results are predicted with LMFBR materials
Decontamination flowsheet development for a waste oil containing mixed radioactive contaminants
International Nuclear Information System (INIS)
Vijayan, S.; Buckley, L.P.
1993-01-01
The majority of waste oils contaminated with both radioactive and hazardous components are generated in nuclear power plant, research lab. and uranium-refinery operations. The waste oils are complex, requiring a detailed examination of the waste management strategies and technology options. It may appear that incineration offers a total solution, but this may not be true in all cases. An alternative approach is to decontaminate the waste oils to very low contaminant levels, so that the treated oils can be reused, burned as fuel in boilers, or disposed of by commercial incineration. This paper presents selected experimental data and evaluation results gathered during the development of a decontamination flowsheet for a specific waste oil stores at Chalk River Labs. (CRL). The waste oil contains varying amounts of lube oils, grease, paint, water, particulates, sludge, light chloro- and fluoro-solvents, polychlorinated biphenyls (PCB), complexing chemicals, uranium, chromium, iron, arsenic and manganese. To achieve safe management of this radioactive and hazardous waste, several treatment and disposal methods were screened. Key experiments were performed at the laboratory-scale to confirm and select the most appropriate waste-management scheme based on technical, environmental and economic criteria. The waste-oil-decontamination flowsheet uses a combination of unit operations, including prefiltration, acid scrubbing, and aqueous-leachage treatment by precipitation, microfiltration, filter pressing and carbon adsorption. The decontaminated oil containing open-quotes de minimisclose quotes levels of contaminants will undergo chemical destruction of PCBs and final disposal by incineration. The recovered uranium will be recycled to a uranium milling process
FY13 GLYCOLIC-NITRIC ACID FLOWSHEET DEMONSTRATIONS OF THE DWPF CHEMICAL PROCESS CELL WITH SIMULANTS
Energy Technology Data Exchange (ETDEWEB)
Lambert, D.; Zamecnik, J.; Best, D.
2014-03-13
Savannah River Remediation is evaluating changes to its current Defense Waste Processing Facility flowsheet to replace formic acid with glycolic acid in order to improve processing cycle times and decrease by approximately 100x the production of hydrogen, a potentially flammable gas. Higher throughput is needed in the Chemical Processing Cell since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the safety significant gas chromatographs and the potential for production of flammable quantities of hydrogen, eliminating the use of formic acid is highly desirable. Previous testing at the Savannah River National Laboratory has shown that replacing formic acid with glycolic acid allows the reduction and removal of mercury without significant catalytic hydrogen generation. Five back-to-back Sludge Receipt and Adjustment Tank (SRAT) cycles and four back-to-back Slurry Mix Evaporator (SME) cycles were successful in demonstrating the viability of the nitric/glycolic acid flowsheet. The testing was completed in FY13 to determine the impact of process heels (approximately 25% of the material is left behind after transfers). In addition, back-to-back experiments might identify longer-term processing problems. The testing was designed to be prototypic by including sludge simulant, Actinide Removal Product simulant, nitric acid, glycolic acid, and Strip Effluent simulant containing Next Generation Solvent in the SRAT processing and SRAT product simulant, decontamination frit slurry, and process frit slurry in the SME processing. A heel was produced in the first cycle and each subsequent cycle utilized the remaining heel from the previous cycle. Lower SRAT purges were utilized due to the low hydrogen generation. Design basis addition rates and boilup rates were used so the processing time was shorter than current processing rates.
Calculation of the 3D density model of the Earth
Piskarev, A.; Butsenko, V.; Poselov, V.; Savin, V.
2009-04-01
The study of the Earth's crust is a part of investigation aimed at extension of the Russian Federation continental shelf in the Sea of Okhotsk Gathered data allow to consider the Sea of Okhotsk' area located outside the exclusive economic zone of the Russian Federation as the natural continuation of Russian territory. The Sea of Okhotsk is an Epi-Mesozoic platform with Pre-Cenozoic heterogeneous folded basement of polycyclic development and sediment cover mainly composed of Paleocene - Neocene - Quaternary deposits. Results of processing and complex interpretation of seismic, gravity, and aeromagnetic data along profile 2-DV-M, as well as analysis of available geological and geophysical information on the Sea of Okhotsk region, allowed to calculate of the Earth crust model. 4 layers stand out (bottom-up) in structure of the Earth crust: granulite-basic (density 2.90 g/cm3), granite-gneiss (limits of density 2.60-2.76 g/cm3), volcanogenic-sedimentary (2.45 g/cm3) and sedimentary (density 2.10 g/cm3). The last one is absent on the continent; it is observed only on the water area. Density of the upper mantle is taken as 3.30 g/cm3. The observed gravity anomalies are mostly related to the surface relief of the above mentioned layers or to the density variations of the granite-metamorphic basement. So outlining of the basement blocks of different constitution preceded to the modeling. This operation is executed after Double Fourier Spectrum analysis of the gravity and magnetic anomalies and following compilation of the synthetic anomaly maps, related to the basement density and magnetic heterogeneity. According to bathymetry data, the Sea of Okhotsk can be subdivided at three mega-blocks. Taking in consideration that central Sea of Okhotsk area is aseismatic, i.e. isostatic compensated, it is obvious that Earth crust structure of these three blocks is different. The South-Okhotsk depression is characteristics by 3200-3300 m of sea depths. Moho surface in this area is at
Power plant reliability calculation with Markov chain models
International Nuclear Information System (INIS)
Senegacnik, A.; Tuma, M.
1998-01-01
In the paper power plant operation is modelled using continuous time Markov chains with discrete state space. The model is used to compute the power plant reliability and the importance and influence of individual states, as well as the transition probabilities between states. For comparison the model is fitted to data for coal and nuclear power plants recorded over several years. (orig.) [de
Calculation of single chain cellulose elasticity using fully atomistic modeling
Xiawa Wu; Robert J. Moon; Ashlie Martini
2011-01-01
Cellulose nanocrystals, a potential base material for green nanocomposites, are ordered bundles of cellulose chains. The properties of these chains have been studied for many years using atomic-scale modeling. However, model predictions are difficult to interpret because of the significant dependence of predicted properties on model details. The goal of this study is...
Model calculation for energy loss in ion-surface collisions
International Nuclear Information System (INIS)
Miraglia, J.E.; Gravielle, M.S.
2003-01-01
The so-called local plasma approximation is generalized to deal with projectiles colliding with surfaces of amorphous solids and with a specific crystalline structure (plannar channeling). Energy loss of protons grazingly colliding with aluminum, SnTe alloy, and LiF surfaces is investigated. The calculations agree quite well with previous theoretical results and explain the experimental findings of energy loss for aluminum and SnTe alloy, but they fall short to explain the data for LiF surfaces
Model Hamiltonian Calculations of the Nonlinear Polarizabilities of Conjugated Molecules.
Risser, Steven Michael
This dissertation advances the theoretical knowledge of the nonlinear polarizabilities of conjugated molecules. The unifying feature of these molecules is an extended delocalized pi electron structure. The pi electrons dominate the electronic properties of the molecules, allowing prediction of molecular properties based on the treatment of just the pi electrons. Two separate pi electron Hamiltonians are used in the research. The principal Hamiltonian used is the non-interacting single-particle Huckel Hamiltonian, which replaces the Coulomb interaction among the pi electrons with a mean field interaction. The simplification allows for exact solution of the Hamiltonian for large molecules. The second Hamiltonian used for this research is the interacting multi-particle Pariser-Parr-Pople (PPP) Hamiltonian, which retains explicit Coulomb interactions. This limits exact solutions to molecules containing at most eight electrons. The molecular properties being investigated are the linear polarizability, and the second and third order hyperpolarizabilities. The hyperpolarizabilities determine the nonlinear optical response of materials. These molecular parameters are determined by two independent approaches. The results from the Huckel Hamiltonian are obtained through first, second and third order perturbation theory. The results from the PPP Hamiltonian are obtained by including the applied field directly in the Hamiltonian and determining the ground state energy at a series of field strengths. By fitting the energy to a polynomial in field strength, the polarizability and hyperpolarizabilities are determined. The Huckel Hamiltonian is used to calculate the third order hyperpolarizability of polyenes. These calculations were the first to show the average hyperpolarizability of the polyenes to be positive, and also to show the saturation of the hyperpolarizability. Comparison of these Huckel results to those from the PPP Hamiltonian shows the lack of explicit Coulomb
Energy Technology Data Exchange (ETDEWEB)
Moeller, M. P.; Urbanik, II, T.; Desrosiers, A. E.
1982-03-01
This paper describes the methodology and application of the computer model CLEAR (Calculates Logical Evacuation And Response) which estimates the time required for a specific population density and distribution to evacuate an area using a specific transportation network. The CLEAR model simulates vehicle departure and movement on a transportation network according to the conditions and consequences of traffic flow. These include handling vehicles at intersecting road segments, calculating the velocity of travel on a road segment as a function of its vehicle density, and accounting for the delay of vehicles in traffic queues. The program also models the distribution of times required by individuals to prepare for an evacuation. In order to test its accuracy, the CLEAR model was used to estimate evacuatlon tlmes for the emergency planning zone surrounding the Beaver Valley Nuclear Power Plant. The Beaver Valley site was selected because evacuation time estimates had previously been prepared by the licensee, Duquesne Light, as well as by the Federal Emergency Management Agency and the Pennsylvania Emergency Management Agency. A lack of documentation prevented a detailed comparison of the estimates based on the CLEAR model and those obtained by Duquesne Light. However, the CLEAR model results compared favorably with the estimates prepared by the other two agencies.
International Nuclear Information System (INIS)
Moeller, M.P.; Desrosiers, A.E.; Urbanik, T. II
1982-03-01
This paper describes the methodology and application of the computer model CLEAR (Calculates Logical Evacuation And Response) which estimates the time required for a specific population density and distribution to evacuate an area using a specific transportation network. The CLEAR model simulates vehicle departure and movement on a transportation network according to the conditions and consequences of traffic flow. These include handling vehicles at intersecting road segments, calculating the velocity of travel on a road segment as a function of its vehicle density, and accounting for the delay of vehicles in traffic queues. The program also models the distribution of times required by individuals to prepare for an evacuation. In order to test its accuracy, the CLEAR model was used to estimate evacuation times for the emergency planning zone surrounding the Beaver Valley Nuclear Power Plant. The Beaver Valley site was selected because evacuation time estimates had previously been prepared by the licensee, Duquesne Light, as well as by the Federal Emergency Management Agency and the Pennsylvania Emergency Management Agency. A lack of documentation prevented a detailed comparison of the estimates based on the CLEAR model and those obtained by Duquesne Light. However, the CLEAR model results compared favorably with the estimates prepared by the other two agencies. (author)
Energy Technology Data Exchange (ETDEWEB)
Meeks, E.; Chou, C. -P.; Garratt, T.
2013-03-31
Engineering simulations of coal gasifiers are typically performed using computational fluid dynamics (CFD) software, where a 3-D representation of the gasifier equipment is used to model the fluid flow in the gasifier and source terms from the coal gasification process are captured using discrete-phase model source terms. Simulations using this approach can be very time consuming, making it difficult to imbed such models into overall system simulations for plant design and optimization. For such system-level designs, process flowsheet software is typically used, such as Aspen Plus® [1], where each component where each component is modeled using a reduced-order model. For advanced power-generation systems, such as integrated gasifier/gas-turbine combined-cycle systems (IGCC), the critical components determining overall process efficiency and emissions are usually the gasifier and combustor. Providing more accurate and more computationally efficient reduced-order models for these components, then, enables much more effective plant-level design optimization and design for control. Based on the CHEMKIN-PRO and ENERGICO software, we have developed an automated methodology for generating an advanced form of reduced-order model for gasifiers and combustors. The reducedorder model offers representation of key unit operations in flowsheet simulations, while allowing simulation that is fast enough to be used in iterative flowsheet calculations. Using high-fidelity fluiddynamics models as input, Reaction Design’s ENERGICO® [2] software can automatically extract equivalent reactor networks (ERNs) from a CFD solution. For the advanced reduced-order concept, we introduce into the ERN a much more detailed kinetics model than can be included practically in the CFD simulation. The state-of-the-art chemistry solver technology within CHEMKIN-PRO allows that to be accomplished while still maintaining a very fast model turn-around time. In this way, the ERN becomes the basis for
Carbon dioxide fluid-flow modeling and injectivity calculations
Burke, Lauri
2011-01-01
At present, the literature lacks a geologic-based assessment methodology for numerically estimating injectivity, lateral migration, and subsequent long-term containment of supercritical carbon dioxide that has undergone geologic sequestration into subsurface formations. This study provides a method for and quantification of first-order approximations for the time scale of supercritical carbon dioxide lateral migration over a one-kilometer distance through a representative volume of rock. These calculations provide a quantified foundation for estimating injectivity and geologic storage of carbon dioxide.
Quark model calculations of current correlators in the nonperturbative domain
International Nuclear Information System (INIS)
Celenza, L.S.; Shakin, C.M.; Sun, W.D.
1995-01-01
The authors study the vector-isovector current correlator in this work, making use of a generalized Nambu-Jona-Lasinio (NJL) model. In their work, the original NJL model is extended to describe the coupling of the quark-antiquark states to the two-pion continuum. Further, a model for confinement is introduced that is seen to remove the nonphysical cuts that appear in various amplitudes when the quark and antiquark go on mass shell. Quite satisfactory results are obtained for the correlator. The authors also use the correlator to define a T-matrix for confined quarks and discuss a rho-dominance model for that T-matrix. It is also seen that the Bethe-Salpeter equation that determines the rho mass (in the absence of the coupling to the two-pion continuum) has more satisfactory behavior in the generalized model than in the model without confinement. That improved behavior is here related to the absence of the q bar q cut in the basic quark-loop integral of the generalized model. In this model, it is seen how one may work with both quark and hadron degrees of freedom, with only the hadrons appearing as physical particles. 12 refs., 16 figs., 1 tab
Real-time dispersion calculation using the Lagrange model LASAT
International Nuclear Information System (INIS)
Janicke, L.
1987-01-01
The LASAT (Lagrange Simulation of Aerosol Transport) dispersion model demonstrates pollutant transport in the atmosphere by simulating the paths of representative random samples of pollutant particles on the computer as natural as possible. The author demonstrates the generated particle paths and refers to literature for details of the model algorithm. (DG) [de
Long-Term Calculations with Large Air Pollution Models
DEFF Research Database (Denmark)
Ambelas Skjøth, C.; Bastrup-Birk, A.; Brandt, J.
1999-01-01
Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...
A review of Higgs mass calculations in supersymmetric models
DEFF Research Database (Denmark)
Draper, P.; Rzehak, H.
2016-01-01
The discovery of the Higgs boson is both a milestone achievement for the Standard Model and an exciting probe of new physics beyond the SM. One of the most important properties of the Higgs is its mass, a number that has proven to be highly constraining for models of new physics, particularly those...... related to the electroweak hierarchy problem. Perhaps the most extensively studied examples are supersymmetric models, which, while capable of producing a 125 GeV Higgs boson with SM-like properties, do so in non-generic parts of their parameter spaces. We review the computation of the Higgs mass...
A simple model for calculating air pollution within street canyons
Venegas, Laura E.; Mazzeo, Nicolás A.; Dezzutti, Mariana C.
2014-04-01
This paper introduces the Semi-Empirical Urban Street (SEUS) model. SEUS is a simple mathematical model based on the scaling of air pollution concentration inside street canyons employing the emission rate, the width of the canyon, the dispersive velocity scale and the background concentration. Dispersive velocity scale depends on turbulent motions related to wind and traffic. The parameterisations of these turbulent motions include two dimensionless empirical parameters. Functional forms of these parameters have been obtained from full scale data measured in street canyons at four European cities. The sensitivity of SEUS model is studied analytically. Results show that relative errors in the evaluation of the two dimensionless empirical parameters have less influence on model uncertainties than uncertainties in other input variables. The model estimates NO2 concentrations using a simple photochemistry scheme. SEUS is applied to estimate NOx and NO2 hourly concentrations in an irregular and busy street canyon in the city of Buenos Aires. The statistical evaluation of results shows that there is a good agreement between estimated and observed hourly concentrations (e.g. fractional bias are -10.3% for NOx and +7.8% for NO2). The agreement between the estimated and observed values has also been analysed in terms of its dependence on wind speed and direction. The model shows a better performance for wind speeds >2 m s-1 than for lower wind speeds and for leeward situations than for others. No significant discrepancies have been found between the results of the proposed model and that of a widely used operational dispersion model (OSPM), both using the same input information.
Calculation of the fermionic determinant in the Schwinger model
International Nuclear Information System (INIS)
Dias, S.A.; Linhares, C.A.
1991-01-01
We compute explicitly the fermionic determinant and the effective action for the generalized Schwinger model in two dimensions and compare it with respective results for the particular cases of the Schwinger, chiral Schwinger and axial Schwinger models. The parameters that signal the ambiguity in the regularization scheme fo the determinant are introduced through the point-splitting method. The Wess-Zumino functional is also obtained and compared with the known expressions for the above-mentioned particular cases. (author)
Li, Chang; Wang, Qing; Shi, Wenzhong; Zhao, Sisi
2018-05-01
The accuracy of earthwork calculations that compute terrain volume is critical to digital terrain analysis (DTA). The uncertainties in volume calculations (VCs) based on a DEM are primarily related to three factors: 1) model error (ME), which is caused by an adopted algorithm for a VC model, 2) discrete error (DE), which is usually caused by DEM resolution and terrain complexity, and 3) propagation error (PE), which is caused by the variables' error. Based on these factors, the uncertainty modelling and analysis of VCs based on a regular grid DEM are investigated in this paper. Especially, how to quantify the uncertainty of VCs is proposed by a confidence interval based on truncation error (TE). In the experiments, the trapezoidal double rule (TDR) and Simpson's double rule (SDR) were used to calculate volume, where the TE is the major ME, and six simulated regular grid DEMs with different terrain complexity and resolution (i.e. DE) were generated by a Gauss synthetic surface to easily obtain the theoretical true value and eliminate the interference of data errors. For PE, Monte-Carlo simulation techniques and spatial autocorrelation were used to represent DEM uncertainty. This study can enrich uncertainty modelling and analysis-related theories of geographic information science.
An hydrodynamic model for the calculation of oil spills trajectories
Energy Technology Data Exchange (ETDEWEB)
Paladino, Emilio Ernesto; Maliska, Clovis Raimundo [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Dinamica dos Fluidos Computacionais]. E-mails: emilio@sinmec.ufsc.br; maliska@sinmec.ufsc.br
2000-07-01
The aim of this paper is to present a mathematical model and its numerical treatment to forecast oil spills trajectories in the sea. The knowledge of the trajectory followed by an oil slick spilled on the sea is of fundamental importance in the estimation of potential risks for pipeline and tankers route selection, and in combating the pollution using floating barriers, detergents, etc. In order to estimate these slicks trajectories a new model, based on the mass and momentum conservation equations is presented. The model considers the spreading in the regimes when the inertial and viscous forces counterbalance gravity and takes into account the effects of winds and water currents. The inertial forces are considered for the spreading and the displacement of the oil slick, i.e., is considered its effects on the movement of the mass center of the slick. The mass loss caused by oil evaporation is also taken into account. The numerical model is developed in generalized coordinates, making the model easily applicable to complex coastal geographies. (author)
Uncertain hybrid model for the response calculation of an alternator
International Nuclear Information System (INIS)
Kuczkowiak, Antoine
2014-01-01
The complex structural dynamic behavior of alternator must be well understood in order to insure their reliable and safe operation. The numerical model is however difficult to construct mainly due to the presence of a high level of uncertainty. The objective of this work is to provide decision support tools in order to assess the vibratory levels in operation before to restart the alternator. Based on info-gap theory, a first decision support tool is proposed: the objective here is to assess the robustness of the dynamical response to the uncertain modal model. Based on real data, the calibration of an info-gap model of uncertainty is also proposed in order to enhance its fidelity to reality. Then, the extended constitutive relation error is used to expand identified mode shapes which are used to assess the vibratory levels. The robust expansion process is proposed in order to obtain robust expanded mode shapes to parametric uncertainties. In presence of lack-of knowledge, the trade-off between fidelity-to-data and robustness-to-uncertainties which expresses that robustness improves as fidelity deteriorates is emphasized on an industrial structure by using both reduced order model and surrogate model techniques. (author)
Model for calculation of concentration and load on behalf of accidents with radioactive materials
International Nuclear Information System (INIS)
Janssen, L.A.M.; Heugten, W.H.H. van
1987-04-01
In the project 'Information- and calculation-system for disaster combatment', by order of the Dutch government, a demonstration model has been developed for a diagnosis system for accidents. In this demonstration a model is used to calculate the concentration- and dose-distributions caused by incidental emissions of limited time. This model is described in this report. 4 refs.; 2 figs.; 3 tabs
Uranium decontamination in Purex second plutonium cycle: An example of solvent extraction modeling
International Nuclear Information System (INIS)
Hsu, T.C.
1986-01-01
The existing Purex flowsheet used in the second plutonium cycle at the Savannah River Plant (SRP) does not remove uranium from the plutonium stream. To develop new flowsheets for the Purex second plutonium cycle, computer simulation using SEPHIS was used. SEPHIS is an ORNL-developed solvent extraction simulation code. Box-Wilson experimental design was used to select the minimum set of process conditions simulated. The calculated results were plotted into three-dimensional response surfaces by SAS/Graph (statistical analysis systems). These surfaces provide a broad and complete overview of the responses. Specific ranges of key variables were then investigated. The second series of process simulations identified flowsheets that provide high uranium decontamination while meeting all other key process requirements. The proposed flowsheet consists of modifying the existing 2B bank flowsheet by relocating the feed, increasing the extractant acidity, and adding a scrub stream. The nuclear safety issue was also examined
A calculation model for the noise from steel railway bridges
Janssens, M.H.A.; Thompson, D.J.
1996-01-01
The sound level of a train crossing a steel railway bridge is usually about 10 dB higher than on plain track. In the Netherlands there are many such bridges which, for practical reasons, cannot be replaced by more intrinsically quiet concrete bridges. A computational model is described for the
Reactor accident calculation models in use in the Nordic countries
International Nuclear Information System (INIS)
Tveten, U.
1984-01-01
The report relates to a subproject under a Nordic project called ''Large reactor accidents - consequences and mitigating actions''. In the first part of the report short descriptions of the various models are given. A systematic list by subject is then given. In the main body of the report chapter and subchapter headings are by subject. (Auth.)
A calculation model for a HTR core seismic response
International Nuclear Information System (INIS)
Buland, P.; Berriaud, C.; Cebe, E.; Livolant, M.
1975-01-01
The paper presents the experimental results obtained at Saclay on a HTGR core model and comparisons with analytical results. Two series of horizontal tests have been performed on the shaking table VESUVE: sinusoidal test and time history response. Acceleration of graphite blocks, forces on the boundaries, relative displacement of the core and PCRB model, impact velocity of the blocks on the boundaries were recorded. These tests have shown the strongly non-linear dynamic behaviour of the core. The resonant frequency of the core is dependent on the level of the excitation. These phenomena have been explained by a computer code, which is a lumped mass non-linear model. Good correlation between experimental and analytical results was obtained for impact velocities and forces on the boundaries. This comparison has shown that the damping of the core is a critical parameter for the estimation of forces and velocities. Time history displacement at the level of PCRV was reproduced on the shaking table. The analytical model was applied to this excitation and good agreement was obtained for forces and velocities. (orig./HP) [de
Glass viscosity calculation based on a global statistical modelling approach
Energy Technology Data Exchange (ETDEWEB)
Fluegel, Alex
2007-02-01
A global statistical glass viscosity model was developed for predicting the complete viscosity curve, based on more than 2200 composition-property data of silicate glasses from the scientific literature, including soda-lime-silica container and float glasses, TV panel glasses, borosilicate fiber wool and E type glasses, low expansion borosilicate glasses, glasses for nuclear waste vitrification, lead crystal glasses, binary alkali silicates, and various further compositions from over half a century. It is shown that within a measurement series from a specific laboratory the reported viscosity values are often over-estimated at higher temperatures due to alkali and boron oxide evaporation during the measurement and glass preparation, including data by Lakatos et al. (1972) and the recently published High temperature glass melt property database for process modeling by Seward et al. (2005). Similarly, in the glass transition range many experimental data of borosilicate glasses are reported too high due to phase separation effects. The developed global model corrects those errors. The model standard error was 9-17°C, with R^2 = 0.985-0.989. The prediction 95% confidence interval for glass in mass production largely depends on the glass composition of interest, the composition uncertainty, and the viscosity level. New insights in the mixed-alkali effect are provided.
Semiclassical calculation for collision induced dissociation. II. Morse oscillator model
International Nuclear Information System (INIS)
Rusinek, I.; Roberts, R.E.
1978-01-01
A recently developed semiclassical procedure for calculating collision induced dissociation probabilities P/sup diss/ is applied to the collinear collision between a particle and a Morse oscillator diatomic. The particle--diatom interaction is described with a repulsive exponential potential function. P/sup diss/ is reported for a system of three identical particles, as a function of collision energy E/sub t/ and initial vibrational state of the diatomic n 1 . The results are compared with the previously reported values for the collision between a particle and a truncated harmonic oscillator. The two studies show similar features, namely: (a) there is an oscillatory structure in the P/sup diss/ energy profiles, which is directly related to n 1 ; (b) P/sup diss/ becomes noticeable (> or approx. =10 -3 ) for E/sub t/ values appreciably higher than the energetic threshold; (c) vibrational enhancement (inhibition) of collision induced dissociation persists at low (high) energies; and (d) good agreement between the classical and semiclassical results is found above the classical dynamic threshold. Finally, the convergence of P/sup diss/ for increasing box length is shown to be rapid and satisfactory
Approximate models for neutral particle transport calculations in ducts
International Nuclear Information System (INIS)
Ono, Shizuca
2000-01-01
The problem of neutral particle transport in evacuated ducts of arbitrary, but axially uniform, cross-sectional geometry and isotropic reflection at the wall is studied. The model makes use of basis functions to represent the transverse and azimuthal dependences of the particle angular flux in the duct. For the approximation in terms of two basis functions, an improvement in the method is implemented by decomposing the problem into uncollided and collided components. A new quadrature set, more suitable to the problem, is developed and generated by one of the techniques of the constructive theory of orthogonal polynomials. The approximation in terms of three basis functions is developed and implemented to improve the precision of the results. For both models of two and three basis functions, the energy dependence of the problem is introduced through the multigroup formalism. The results of sample problems are compared to literature results and to results of the Monte Carlo code, MCNP. (author)
Aeroelastic Calculations Using CFD for a Typical Business Jet Model
Gibbons, Michael D.
1996-01-01
Two time-accurate Computational Fluid Dynamics (CFD) codes were used to compute several flutter points for a typical business jet model. The model consisted of a rigid fuselage with a flexible semispan wing and was tested in the Transonic Dynamics Tunnel at NASA Langley Research Center where experimental flutter data were obtained from M(sub infinity) = 0.628 to M(sub infinity) = 0.888. The computational results were computed using CFD codes based on the inviscid TSD equation (CAP-TSD) and the Euler/Navier-Stokes equations (CFL3D-AE). Comparisons are made between analytical results and with experiment where appropriate. The results presented here show that the Navier-Stokes method is required near the transonic dip due to the strong viscous effects while the TSD and Euler methods used here provide good results at the lower Mach numbers.
Model calculation of the scanned field enhancement factor of CNTs
International Nuclear Information System (INIS)
Ahmad, Amir; Tripathi, V K
2006-01-01
The field enhancement factor of a carbon nanotube (CNT) placed in a cluster of CNTs is smaller than an isolated CNT because the electric field on one tube is screened by neighbouring tubes. This screening depends on the length of the CNTs and the spacing between them. We have derived an expression to compute the field enhancement factor of CNTs under any positional distribution of CNTs using a model of a floating sphere between parallel anode and cathode plates. Using this expression we can compute the field enhancement factor of a CNT in a cluster (non-uniformly distributed CNTs). This expression is used to compute the field enhancement factor of a CNT in an array (uniformly distributed CNTs). Comparison has been shown with experimental results and existing models
Quark model calculation of charmed baryon production by neutrinos
International Nuclear Information System (INIS)
Avilez, C.; Kobayashi, T.; Koerner, J.G.
1976-11-01
We study the neutrino production of 25 low-lying charmed baryon resonances in the four flavour quark model. The mass difference of ordinary and charmed quarks is explicitly taken into account. The quark model is used to determine the spectrum of the charmed baryon resonances and the q 2 = 0 values of the weak current transition matrix elements. These transition matrix elements are then continued to space-like q 2 -values by a generalized meson dominance ansatz for a set of suitably chosen invariant form factors. We find that the production of the L = 0 states C 0 , C 1 and C 1 * is dominant, with the C 0 produced most copiously. For L = 1, 2 the Jsup(P) = 3/2 - 5/2 + charm states are dominant. We give differential cross sections, total cross sections and energy integrated total cross sections using experimental neutrino fluxes. (orig./BJ) [de
Microscopic calculation of parameters of the sdg interacting boson model for 104-110Pd isotopes
International Nuclear Information System (INIS)
Liu Yong
1995-01-01
The parameters of the sdg interacting boson model Hamiltonian are calculated for the 104-110 Pd isotopes. The calculations utilize the microscopic procedure based on the Dyson boson mapping proposed by Yang-Liu-Qi and extended to include the g boson effects. The calculated parameters reproduce those values from the phenomenological fits. The resulting spectra are compared with the experimental spectra
Static model calculation of pion-nucleon scattering
International Nuclear Information System (INIS)
Itoh, Takashi
1975-01-01
The p-wave pion-nucleon scattering phase-shifts are computed by the Chew-Low static model for pion incident energy of 0-300 MeV. The square of the unrenormalized coupling constant is taken to be f 2 =0.2, and the cutoff is made at k sub(max)=6μ. The computed 3,3 phase-shift passes through 90 deg about at the right energy. The other phase-shifts computed are small in rough agreement with experiment. (auth.)
Simplified models for radiational losses calculating a tokamak plasma
International Nuclear Information System (INIS)
Arutiunov, A.B.; Krasheninnikov, S.I.; Prokhorov, D.Yu.
1990-01-01
To determine the magnitudes and profiles of radiational losses in a Tokamak plasma, particularly for high plasma densities, when formation of MARFE or detached-plasma takes place, it is necessary to know impurity distribution over the ionization states. Equations describing time evolution of this distribution are rather cumbersome, besides that, transport coefficients as well as rate constants of the processes involving complex ions are known nowadays with high degree of uncertainty, thus it is believed necessary to develop simplified, half-analytical models describing time evolution of the impurities analysis of physical processes taking place in a Tokamak plasma on the base of the experimental data. (author) 6 refs., 2 figs
Nuclear matter calculations with a pseudoscalar-pseudovector chiral model
Energy Technology Data Exchange (ETDEWEB)
Niembro, R.; Marcos, S.; Bernardos, P. [University of Cantabria, Faculty of Sciences, Department of Modern Physics, 39005 Santander (Spain); Fomenko, V.N. [St Petersburg University for Railway Engineering, Department of Mathematics, 197341 St Petersburg (Russian Federation); Savushkin, L.N. [St Petersburg University for Telecomunications, Department of Physics, 191065 St Petersburg (Russian Federation); Lopez-Quelle, M. [University of Cantabria, Faculty of Sciences, Department of Applied Physics, 39005 Santander, Spain (Spain)
1998-10-01
A mixed pseudoscalar-pseudovector {pi}N coupling relativistic Lagrangian is obtained from a pure pseudoscalar chiral one, by transforming the nucleon field according to a generalized Weinberg transformation, which depends on a mixing parameter. The interaction is generated by the {sigma}, {omega} and {pi} meson exchanges. Within the Hartree-Fock context, pion polarization effects, including the {delta} isobar, are considered in the random phase approximation in nuclear matter. These effects are interpreted, in a non-relativistic framework, as a modification of the range and intensity of a Yukawa-type potential by means of a simple function which takes into account the nucleon-hole and {delta}-hole excitations. Results show stability of relativistic nuclear matter against pion condensation. Compression modulus is diminished by the combined effects of the nucleon and {delta} polarization towards the usually accepted experimental values. The {pi}N interaction strength used in this paper is less than the conventional one to ensure the viability of the model. The fitting parameters of the model are the scalar meson mass m{sub {sigma}} and the {omega}-N coupling constant g{sub {omega}}. (author)
Predictive Modelling Risk Calculators and the Non Dialysis Pathway.
Robins, Jennifer; Katz, Ivor
2013-04-16
This guideline will review the current prediction models and survival/mortality scores available for decision making in patients with advanced kidney disease who are being considered for a non-dialysis treatment pathway. Risk prediction is gaining increasing attention with emerging literature suggesting improved patient outcomes through individualised risk prediction (1). Predictive models help inform the nephrologist and the renal palliative care specialists in their discussions with patients and families about suitability or otherwise of dialysis. Clinical decision making in the care of end stage kidney disease (ESKD) patients on a non-dialysis treatment pathway is currently governed by several observational trials (3). Despite the paucity of evidence based medicine in this field, it is becoming evident that the survival advantages associated with renal replacement therapy in these often elderly patients with multiple co-morbidities and limited functional status may be negated by loss of quality of life (7) (6), further functional decline (5, 8), increased complications and hospitalisations. This article is protected by copyright. All rights reserved.
The curvature calculation mechanism based on simple cell model.
Yu, Haiyang; Fan, Xingyu; Song, Aiqi
2017-07-20
A conclusion has not yet been reached on how exactly the human visual system detects curvature. This paper demonstrates how orientation-selective simple cells can be used to construct curvature-detecting neural units. Through fixed arrangements, multiple plurality cells were constructed to simulate curvature cells with a proportional output to their curvature. In addition, this paper offers a solution to the problem of narrow detection range under fixed resolution by selecting an output value under multiple resolution. Curvature cells can be treated as concrete models of an end-stopped mechanism, and they can be used to further understand "curvature-selective" characteristics and to explain basic psychophysical findings and perceptual phenomena in current studies.
Significance of mineralogy in the development of flowsheets for processing uranium ores
International Nuclear Information System (INIS)
1980-01-01
This report has been prepared from material developed at and subsequent to a consultants' meeting held in Vienna in January 1978. The main purpose of the meeting was to prepare a document in the form of a guide for planning and developing treatment flowsheets for uranium ore processing. It was apparent that ore mineralogy, analysed, described and interpreted in ways most meaningful to the metallurgist, is the most essential information required for forming the basis of such planning. This topic, here termed metallurgical mineralogy, is therefore a major theme of this publication. In preparing the report the Agency has borne in mind the important need to impart the experience and knowledge gained in the more developed countries to those who are in the early stages of exploiting their uranium resources. The contents may be criticized as lacking, in some respects, the requisite depth and detail of treatment. The Agency and the consultants are conscious of the need to expand the information in a number of ways. However, the report is presented in its present form in the belief that, as the first attempt to correlate, on a world-wide basis, ore type with processing, it will be considered as a useful basis for future development of these themes
Towards an optimized flow-sheet for a SANEX demonstration process using centrifugal contactors
International Nuclear Information System (INIS)
Magnusson, D.; Christiansen, B.; Glatz, J.P.; Malmbeck, R.; Serrano-Purroy, D.; Modolo, G.; Sorel, C.
2008-01-01
The design of an efficient process flow-sheet requires accurate extraction data for the experimental set-up used. Often this data is provided as equilibrium data. Due to the small hold-up volume compared to the flow rate in centrifugal contactors the time for extraction is often too short to reach the equilibrium D-ratios. In this work single stage kinetics experiments have been carried out to investigate the D-ratio dependence of the flow rate and also to compare with equilibrium batch experiments for CyMe 4 - BTBP. The first centrifuge experiment was run with spiked solutions while in the second a genuine actinide/lanthanide fraction from a TODGA process was used. Three different flow rates were tested with each set-up. The results show that even with low flow rates, around 8% of the equilibrium D-ratio (Am) was reached for the extraction in the spiked test and around 16% in the hot test (the difference is due to the size of the centrifuges). The general conclusion is that the development of a process flow sheet needs investigation of the kinetic behaviour in the actual equipment used. (authors)
Influence of FRAPCON-1 evaluation models on fuel behavior calculations for commercial power reactors
International Nuclear Information System (INIS)
Chambers, R.; Laats, E.T.
1981-01-01
A preliminary set of nine evaluation models (EMs) was added to the FRAPCON-1 computer code, which is used to calculate fuel rod behavior in a nuclear reactor during steady-state operation. The intent was to provide an audit code to be used in the United States Nuclear Regulatory Commission (NRC) licensing activities when calculations of conservative fuel rod temperatures are required. The EMs place conservatisms on the calculation of rod temperature by modifying the calculation of rod power history, fuel and cladding behavior models, and materials properties correlations. Three of the nine EMs provide either input or model specifications, or set the reference temperature for stored energy calculations. The remaining six EMs were intended to add thermal conservatism through model changes. To determine the relative influence of these six EMs upon fuel behavior calculations for commercial power reactors, a sensitivity study was conducted. That study is the subject of this paper
User Guide for GoldSim Model to Calculate PA/CA Doses and Limits
International Nuclear Information System (INIS)
Smith, F.
2016-01-01
A model to calculate doses for solid waste disposal at the Savannah River Site (SRS) and corresponding disposal limits has been developed using the GoldSim commercial software. The model implements the dose calculations documented in SRNL-STI-2015-00056, Rev. 0 ''Dose Calculation Methodology and Data for Solid Waste Performance Assessment (PA) and Composite Analysis (CA) at the Savannah River Site''.
User Guide for GoldSim Model to Calculate PA/CA Doses and Limits
Energy Technology Data Exchange (ETDEWEB)
Smith, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-10-31
A model to calculate doses for solid waste disposal at the Savannah River Site (SRS) and corresponding disposal limits has been developed using the GoldSim commercial software. The model implements the dose calculations documented in SRNL-STI-2015-00056, Rev. 0 “Dose Calculation Methodology and Data for Solid Waste Performance Assessment (PA) and Composite Analysis (CA) at the Savannah River Site”.
A model for calculating expected performance of the Apollo unified S-band (USB) communication system
Schroeder, N. W.
1971-01-01
A model for calculating the expected performance of the Apollo unified S-band (USB) communication system is presented. The general organization of the Apollo USB is described. The mathematical model is reviewed and the computer program for implementation of the calculations is included.
Improvements to the nuclear model code GNASH for cross section calculations at higher energies
International Nuclear Information System (INIS)
Young, P.G.; Chadwick, M.B.
1994-01-01
The nuclear model code GNASH, which in the past has been used predominantly for incident particle energies below 20 MeV, has been modified extensively for calculations at higher energies. The model extensions and improvements are described in this paper, and their significance is illustrated by comparing calculations with experimental data for incident energies up to 160 MeV
Cost calculation model concerning small-scale production of chips and split firewood
International Nuclear Information System (INIS)
Ryynaenen, S.; Naett, H.; Valkonen, J.
1995-01-01
The TTS-Institute's Forestry Department has developed a computer-based cost calculation model for the production of wood chips and split firewood. This development work was carried out in conjunction with the nation-wide BIOENERGY -research programme. The said calculation model eases and speeds up the calculation of unit costs and resource needs in harvesting systems for wood chips and split firewood. The model also enables the user to find out how changes in the productivity and costs bases of different harvesting chains influences the unit costs of the system as a whole. The undertaking was composed of the following parts: clarification and modification of productivity bases for application in the model as mathematical models, clarification of machine and device costs bases, designing of the structure and functions of the calculation model, construction and testing of the model's 0-version, model calculations concerning typical chains, review of calculation bases, and charting of development needs focusing on the model. The calculation model was developed to serve research needs, but with further development it could be useful as a tool in forestry and agricultural extension work, related schools and colleges, and in the hands of firewood producers. (author)
Development of the model for the stress calculation of fuel assembly under accident load
International Nuclear Information System (INIS)
Kim, Il Kon
1993-01-01
The finite element model for the stress calculation in guide thimbles of a fuel assembly (FA) under seismic and loss-of-coolant-accident (LOCA) load is developed. For the stress calculation of FA under accident load, at first the program MAIN is developed to select the worst bending mode shaped FA from core model. And then the model for the stress calculation of FA is developed by means of the finite element code. The calculated results of program MAIN are used as the kinematic constraints of the finite element model of a FA. Compared the calculated results of the stiffness of the finite element model of FA with the test results they have good agreements. (Author)
Directory of Open Access Journals (Sweden)
Darya Sergeevna Simonenkova
2013-09-01
Full Text Available The subject of the research is analysis of various models of the information system constructed with the use of technologies of cloud calculations. Analysis of models is required for constructing a new reference model which will be used for develop a security threats model.
Report for Treating Hanford LAW and WTP SW Simulants: Pilot Plant Mineralizing Flowsheet
International Nuclear Information System (INIS)
Olson, Arlin
2012-01-01
The US Department of Energy is responsible for managing the disposal of radioactive liquid waste in underground storage tanks at the Hanford site in Washington State. The Hanford waste treatment and immobilization plant (WPT) will separate the waste into a small volume of high level waste (HLW), containing most of the radioactive constituents, and a larger volume of low activity waste (LAW), containing most of the non-radioactive chemical and hazardous constituents. The HLW and LAW will be converted into immobilized waste forms for disposal. Currently there is inadequate LAW vitrification capacity planned at the WTP to complete the mission within the required timeframe. Therefore additional LAW capacity is required. One candidate supplemental treatment technology is the fluidized bed steam reformer process (FBSR). This report describes the demonstration testing of the FBSR process using a mineralizing flowsheet for treating simulated Hanford LAW and secondary waste from the WTP (WTP SW). The FBSR testing project produced leach-resistant solid products and environmentally compliant gaseous effluents. The solid products incorporated normally soluble ions into an alkali alumino-silicate (NaS) mineral matrix. Gaseous emissions were found to be within regulatory limits. Cesium and rhenium were captured in the mineralized products with system removal efficiencies of 99.999% and 99.998 respectively. The durability and leach performance of the FBSR granular solid were superior to the low activity reference material (LMR) glass standards. Normalized product consistency test (PCT) release rates for constituents of concern were approximately 2 orders of magnitude less than that of sodium in the Hanford glass [standard].
Report for Treating Hanford LAW and WTP SW Simulants: Pilot Plant Mineralizing Flowsheet
Energy Technology Data Exchange (ETDEWEB)
Arlin Olson
2012-02-28
The US Department of Energy is responsible for managing the disposal of radioactive liquid waste in underground storage tanks at the Hanford site in Washington State. The Hanford waste treatment and immobilization plant (WPT) will separate the waste into a small volume of high level waste (HLW), containing most of the radioactive constituents, and a larger volume of low activity waste (LAW), containing most of the non-radioactive chemical and hazardous constituents. The HLW and LAW will be converted into immobilized waste forms for disposal. Currently there is inadequate LAW vitrification capacity planned at the WTP to complete the mission within the required timeframe. Therefore additional LAW capacity is required. One candidate supplemental treatment technology is the fluidized bed steam reformer process (FBSR). This report describes the demonstration testing of the FBSR process using a mineralizing flowsheet for treating simulated Hanford LAW and secondary waste from the WTP (WTP SW). The FBSR testing project produced leach-resistant solid products and environmentally compliant gaseous effluents. The solid products incorporated normally soluble ions into an alkali alumino-silicate (NaS) mineral matrix. Gaseous emissions were found to be within regulatory limits. Cesium and rhenium were captured in the mineralized products with system removal efficiencies of 99.999% and 99.998 respectively. The durability and leach performance of the FBSR granular solid were superior to the low activity reference material (LMR) glass standards. Normalized product consistency test (PCT) release rates for constituents of concern were approximately 2 orders of magnitude less than that of sodium in the Hanford glass [standard].
Implementation of the neutronics model of HEXTRAN/HEXBU-3D into APROS for WWER calculations
International Nuclear Information System (INIS)
Rintala, J.
2008-01-01
A new three-dimensional nodal model for neutronics calculation is currently under implementation into APROS - Advanced PROcess Simulation environment - to conform the increasing accuracy requirements. The new model is based on an advanced nodal code HEXTRAN and its static version HEXBU-3D by VTT, Technical Research Centre of Finland. Currently the new APROS is under a testing programme. Later a systematic validation will be performed. In the first phase, a goal is to obtain a fully validated model for VVER-440 calculations. Thus, all the current test calculations are performed by using Loviisa NPP's VVER-440 model of APROS. In future, the model is planned to be applied for the calculations of VVER-1000 type reactors as well as in rectangular fuel geometry. The paper outlines first the general aspects of the method, and then the current situation of the implementation. Because of the identical model with the models of HEXTRAN and HEXBU-3D, the results in the test calculations are compared to the results of those. In the paper, results of two static test calculations are shown. Currently the model works well already in static analyses. Only minor problems with the control assemblies of VVER-440 type reactor still exist but the reasons are known and will be corrected in near future. Dynamical characteristics of the model are up to now tested only by some empirical tests. (author)
Calculation of DC Arc Plasma Torch Voltage- Current Characteristics Based on Steebeck Model
International Nuclear Information System (INIS)
Gnedenko, V.G.; Ivanov, A.A.; Pereslavtsev, A.V.; Tresviatsky, S.S.
2006-01-01
The work is devoted to the problem of the determination of plasma torches parameters and power sources parameters (working voltage and current of plasma torch) at the predesigning stage. The sequence of calculation of voltage-current characteristics of DC arc plasma torch is proposed. It is shown that the simple Steenbeck model of arc discharge in cylindrical channel makes it possible to carry out this calculation. The results of the calculation are confirmed by the experiments
International Nuclear Information System (INIS)
Gasco, C.; Anton, M. P.; Ampudia, J.
2003-01-01
The introduction of macros in try calculation sheets allows the automatic application of various dating models using unsupported ''210 Pb data from a data base. The calculation books the contain the models have been modified to permit the implementation of these macros. The Marine and Aquatic Radioecology group of CIEMAT (MARG) will be involved in new European Projects, thus new models have been developed. This report contains a detailed description of: a) the new implement macros b) the design of a dating Menu in the calculation sheet and c) organization and structure of the data base. (Author) 4 refs
Optimization of the neutron calculation model for the RA-6 reactor
International Nuclear Information System (INIS)
Coscia, G.A.
1981-01-01
A model for the neutronic calculation of the RA-6 reactor which includes the codes ANISN and EQUIPOSE is analyzed. Starting with a brief description of the reactor, the core and its parts, the general scheme of calculation applied is presented. The fuel elements used were those which are utilized in the RA-3 reactor; this is of the MTR type with 90% enriched uranium. With the approximations used, an analysis of such model of calculation was made, trying to optimize it by reducing, if possible, the calculation time without loosing accuracy. In order to improve the calculation model, it is recomended a cross section data library specific for the enrichment of the fuel considered 90% and the incorporation of a more advanced code than EQUIPOISE which would be DIXYBAR. (M.E.L.) [es
Energy Technology Data Exchange (ETDEWEB)
Zhang, Zhen [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Xia, Changliang [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Yan, Yan, E-mail: yanyan@tju.edu.cn [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Geng, Qiang [Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Shi, Tingna [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China)
2017-08-01
Highlights: • A hybrid analytical model is developed for field calculation of multilayer IPM machines. • The rotor magnetic field is calculated by the magnetic equivalent circuit method. • The field in the stator and air-gap is calculated by subdomain technique. • The magnetic scalar potential on rotor surface is modeled as trapezoidal distribution. - Abstract: Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff’s law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell’s equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.
Energy Technology Data Exchange (ETDEWEB)
Druce, C.H.; Barrett, B.R. (Arizona Univ., Tucson (USA). Dept. of Physics); Pittel, S. (Delaware Univ., Newark (USA). Bartol Research Foundation); Duval, P.D. (BEERS Associates, Reston, VA (USA))
1985-07-11
The parameters of the Majorana interaction of the neutron-proton interacting boson model are calculated for the Hg isotopes. The calculations utilize the Otsuka-Arima-Iachello mapping procedure and also lead to predictions for the other boson parameters. The resulting spectra are compared with experimental spectra and those obtained from phenomenological fits.
Druce, C. H.; Pittel, S.; Barrett, B. R.; Duval, P. D.
1985-07-01
The parameters of the Majorana interaction of the neutron-proton interacting boson model are calculated for the Hg isotopes. The calculations utilize the Otsuka-Arima-Iachello mapping procedure and also lead to predictions for the other boson parameters. The resulting spectra are compared with experimental spectra and those obtained from phenomenological fits.
The effect of magnetic field models on cosmic ray cutoff calculations
International Nuclear Information System (INIS)
Pfitzer, K.A.
1979-01-01
The inaccuracies in the 1974 Olson-Pfitzer model appeared to be the probable cause for discrepancies between the observed and calculated cosmic ray cutoff values. An improved version of the Olson-Pfitzer model is now available which includes the effects of the tilt of the earth's dipole axis and which has removed most of the problems encountered in the earlier model. The paper demonstrates that when this new accurate magnetic field model is used, the calculated and observed cutoff values agree with the experimental error without the need for invoking anomalous diffusion mechanisms. This tilt-dependent model also permits a study of cutoffs versus the tilt of the dipole axis
Developing a Model of Tuition Fee Calculation for Universities of Medical Sciences
Directory of Open Access Journals (Sweden)
Seyed Amir Mohsen Ziaee
2018-01-01
Full Text Available Background: The aim of our study was to introduce and evaluate a practicable model for tuition fee calculation of each medical field in universities of medical sciences in Iran.Methods: Fifty experts in 11 panels were interviewed to identify variables that affect tuition fee calculation. This led to key points including total budgets, expenses of the universities, different fields’ attractiveness, universities’ attractiveness, and education quality. Tuition fees were calculated for different levels of education, such as post-diploma, Bachelor, Master, and Doctor of Philosophy (Ph.D degrees, Medical specialty, and Fellowship. After tuition fee calculation, the model was tested during 2013-2015. Since then, a questionnaire including 20 questions was prepared. All Universities’ financial and educational managers were asked to respond to the questions regarding the model’s reliability and effectiveness.Results: According to the results, fields’ attractiveness, universities’ attractiveness, zone distinction and education quality were selected as effective variables for tuition fee calculation. In this model, tuition fees per student were calculated for the year 2013, and, therefore, the inflation rate of the same year was used. Testing of the model showed that there is a 92% of satisfaction. This model is used by medical science universities in Iran.Conclusion: Education quality, zone coefficient, fields’ attractiveness, universities’ attractiveness, inflation rate, and portion of each level of education were the most important variables affecting tuition fee calculation.Keywords: TUITION FEES, FIELD’S ATTRACTIVENESS, UNIVERSITIES’ ATTRACTIVENESS, ZONE DISTINCTION, EDUCATION QUALITY
Strip yielding model for calculation of COD in spheres with short cracks
International Nuclear Information System (INIS)
Miller, A.G.
1981-08-01
The crack opening displacement at the centre of a crack in a sphere with internal pressure has been calculated, using a strip yielding model. The results have been displayed for a range of geometrical parameters and loads. (author)
The contribution of Skyrme Hartree-Fock calculations to the understanding of the shell model
International Nuclear Information System (INIS)
Zamick, L.
1984-01-01
The authors present a detailed comparison of Skyrme Hartree-Fock and the shell model. The H-F calculations are sensitive to the parameters that are chosen. The H-F results justify the use of effective charges in restricted model space calculations by showing that the core contribution can be large. Further, the H-F results roughly justify the use of a constant E2 effective charge, but seem to yield nucleus dependent E4 effective charges. The H-F can yield results for E6 and higher multipoles, which would be zero in s-d model space calculations. On the other side of the coin in H-F the authors can easily consider only the lowest rotational band, whereas in the shell model one can calculate the energies and properties of many more states. In the comparison some apparent problems remain, in particular E4 transitions in the upper half of the s-d shell
Modeling for Dose Rate Calculation of the External Exposure to Gamma Emitters in Soil
International Nuclear Information System (INIS)
Allam, K. A.; El-Mongy, S. A.; El-Tahawy, M. S.; Mohsen, M. A.
2004-01-01
Based on the model proposed and developed in Ph.D thesis of the first author of this work, the dose rate conversion factors (absorbed dose rate in air per specific activity of soil in nGy.hr - 1 per Bq.kg - 1) are calculated 1 m above the ground for photon emitters of natural radionuclides uniformly distributed in the soil. This new and simple dose rate calculation software was used for calculation of the dose rate in air 1 m above the ground. Then the results were compared with those obtained by five different groups. Although the developed model is extremely simple, the obtained results of calculations, based on this model, show excellent agreement with those obtained by the above-mentioned models specially that one adopted by UNSCEAR. (authors)
Chiral Lagrangian calculation of nucleon branching ratios in the supersymmetric SU(5) model
International Nuclear Information System (INIS)
Chadha, S.; Daniel, M.
1983-12-01
The branching ratios are calculated for the two body nucleon decay modes involving pseudoscalars in the minimal SU(5) supersymmetric model with three generations using the techniques of chiral dynamics. (author)
The transition equation of the state intensities for exciton model and the calculation program
International Nuclear Information System (INIS)
Yu Xian; Zheng Jiwen; Liu Guoxing; Chen Keliang
1995-01-01
An equation set of the exciton model is given and calculation program is developed. The process of approaching to equilibrium state has been investigated with the program for 12 C + 64 Ni reaction at energy 72 MeV
Fast and accurate calculation of dilute quantum gas using Uehling–Uhlenbeck model equation
Energy Technology Data Exchange (ETDEWEB)
Yano, Ryosuke, E-mail: ryosuke.yano@tokiorisk.co.jp
2017-02-01
The Uehling–Uhlenbeck (U–U) model equation is studied for the fast and accurate calculation of a dilute quantum gas. In particular, the direct simulation Monte Carlo (DSMC) method is used to solve the U–U model equation. DSMC analysis based on the U–U model equation is expected to enable the thermalization to be accurately obtained using a small number of sample particles and the dilute quantum gas dynamics to be calculated in a practical time. Finally, the applicability of DSMC analysis based on the U–U model equation to the fast and accurate calculation of a dilute quantum gas is confirmed by calculating the viscosity coefficient of a Bose gas on the basis of the Green–Kubo expression and the shock layer of a dilute Bose gas around a cylinder.
Energy Technology Data Exchange (ETDEWEB)
Lambert, D.; Stone, M.; Newell, J.; Best, D.
2012-05-07
Savannah River Remediation (SRR) is evaluating changes to its current DWPF flowsheet to improve processing cycle times. This will enable the facility to support higher canister production while maximizing waste loading. Higher throughput is needed in the CPC since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the DWPF gas chromatographs (GC) and the potential for production of flammable quantities of hydrogen, reducing or eliminating the amount of formic acid used in the CPC is being developed. Earlier work at Savannah River National Laboratory has shown that replacing formic acid with an 80:20 molar blend of glycolic and formic acids has the potential to remove mercury in the SRAT without any significant catalytic hydrogen generation. This report summarizes the research completed to determine the feasibility of processing without formic acid. In earlier development of the glycolic-formic acid flowsheet, one run (GF8) was completed without formic acid. It is of particular interest that mercury was successfully removed in GF8, no formic acid at 125% stoichiometry. Glycolic acid did not show the ability to reduce mercury to elemental mercury in initial screening studies, which is why previous testing focused on using the formic/glycolic blend. The objective of the testing detailed in this document is to determine the viability of the nitric-glycolic acid flowsheet in processing sludge over a wide compositional range as requested by DWPF. This work was performed under the guidance of Task Technical and Quality Assurance Plan (TT and QAP). The details regarding the simulant preparation and analysis have been documented previously.
Energy Technology Data Exchange (ETDEWEB)
Lambert, D.; Stone, M.; Newell, J.; Best, D.; Zamecnik, J.
2012-08-28
Savannah River Remediation (SRR) is evaluating changes to its current Defense Waste Processing Facility (DWPF) flowsheet to improve processing cycle times. This will enable the facility to support higher canister production while maximizing waste loading. Higher throughput is needed in the Chemical Process Cell (CPC) since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the DWPF gas chromatographs (GC) and the potential for production of flammable quantities of hydrogen, reducing or eliminating the amount of formic acid used in the CPC is being developed. Earlier work at Savannah River National Laboratory has shown that replacing formic acid with an 80:20 molar blend of glycolic and formic acids has the potential to remove mercury in the SRAT without any significant catalytic hydrogen generation. This report summarizes the research completed to determine the feasibility of processing without formic acid. In earlier development of the glycolic-formic acid flowsheet, one run (GF8) was completed without formic acid. It is of particular interest that mercury was successfully removed in GF8, no formic acid at 125% stoichiometry. Glycolic acid did not show the ability to reduce mercury to elemental mercury in initial screening studies, which is why previous testing focused on using the formic/glycolic blend. The objective of the testing detailed in this document is to determine the viability of the nitric-glycolic acid flowsheet in processing sludge over a wide compositional range as requested by DWPF. This work was performed under the guidance of Task Technical and Quality Assurance Plan (TT&QAP). The details regarding the simulant preparation and analysis have been documented previously.
NUCORE - A system for nuclear structure calculations with cluster-core models
International Nuclear Information System (INIS)
Heras, C.A.; Abecasis, S.M.
1982-01-01
Calculation of nuclear energy levels and their electromagnetic properties, modelling the nucleus as a cluster of a few particles and/or holes interacting with a core which in turn is modelled as a quadrupole vibrator (cluster-phonon model). The members of the cluster interact via quadrupole-quadrupole and pairing forces. (orig.)
Thermodynamic modeling of the Sc-Zn system coupled with first-principles calculation
Directory of Open Access Journals (Sweden)
Tang C.
2012-01-01
Full Text Available The Sc-Zn system has been critically reviewed and assessed by means of CALPHAD (CALculation of PHAse Diagram approach. By means of first-principles calculation, the enthalpies of formation at 0 K for the ScZn, ScZn2, Sc17Zn58, Sc3Zn17 and ScZn12 have been computed with the desire to assist thermodynamic modeling. A set of self-consistent thermodynamic parameters for the Sc-Zn system is then obtained. The calculated phase diagram and thermodynamic properties agree well with the experimental data and first-principles calculations, respectively.
On thermal vibration effects in diffusion model calculations of blocking dips
International Nuclear Information System (INIS)
Fuschini, E.; Ugozzoni, A.
1983-01-01
In the framework of the diffusion model, a method for calculating blocking dips is suggested that takes into account thermal vibrations of the crystal lattice. Results of calculations of the diffusion factor and the transverse energy distribution taking into accoUnt scattering of the channeled particles at thermal vibrations of lattice nuclei, are presented. Calculations are performed for α-particles with the energy of 2.12 MeV at 300 K scattered by Al crystal. It is shown that calculations performed according to the above method prove the necessity of taking into account effects of multiple scattering under blocking conditions
Heterogeneous neutron-leakage model for PWR pin-by-pin calculation
International Nuclear Information System (INIS)
Li, Yunzhao; Zhang, Bin; Wu, Hongchun; Shen, Wei
2017-01-01
Highlights: •The derivation of the formula of the leakage model is introduced. This paper evaluates homogeneous and heterogeneous leakage models used in PWR pin-by-pin calculation. •The implements of homogeneous and heterogeneous leakage models used in pin-cell homogenization of the lattice calculation are studied. A consistent method of cooperation between the heterogeneous leakage model and the pin-cell homogenization theory is proposed. •Considering the computational cost, a new buckling search scheme is proposed to reach the convergence faster. The computational cost of the newly proposed neutron balance scheme is much less than the power-method scheme and the linear-interpolation scheme. -- Abstract: When assembly calculation is performed with the reflective boundary condition, a leakage model is usually required in the lattice code. The previous studies show that the homogeneous leakage model works effectively for the assembly homogenization. However, it becomes different and unsettled for the pin-cell homogenization. Thus, this paper evaluates homogeneous and heterogeneous leakage models used in pin-by-pin calculation. The implements of homogeneous and heterogeneous leakage models used in pin-cell homogenization of the lattice calculation are studied. A consistent method of cooperation between the heterogeneous leakage model and the pin-cell homogenization theory is proposed. Considering the computational cost, a new buckling search scheme is proposed to reach the convergence faster. For practical reactor-core applications, the diffusion coefficients determined by the transport cross-section or by the leakage model are compared with each other to determine which one is more accurate for the Pressurized Water Reactor pin-by-pin calculation. Numerical results have demonstrated that the heterogeneous leakage model together with the diffusion coefficient determined by the heterogeneous leakage model would have the higher accuracy. The new buckling search
DEFF Research Database (Denmark)
Yuan, Hao; You, Zhenjiang; Shapiro, Alexander
2013-01-01
Colloidal-suspension flow in porous media is modelled simultaneously by the large scale population balance equations and by the microscale network model. The phenomenological parameter of the correlation length in the population balance model is determined from the network modelling. It is found...... out that the correlation length in the population balance model depends on the particle size. This dependency calculated by two-dimensional network has the same tendency as that obtained from the laboratory tests in engineered porous media....
International Nuclear Information System (INIS)
Abbate, P.
1990-01-01
The CONVEC program developed for the thermohydraulic calculation under a natural convection regime for MTR type reactors is presented. The program is based on a stationary, one dimensional model of finite differences that allow to calculate the temperatures of cooler, cladding and fuel as well as the flow for a power level specified by the user. This model has been satisfactorily validated by a water cooling (liquid phase) and air system. (Author) [es
CASIM calculations and angular dependent parameter β in the Moyer model
International Nuclear Information System (INIS)
Yamaguchi, Chiri.
1988-04-01
The dose equivalent on the shield surface has been calculated using both the Moyer model and the Monte Carlo code CASIM. Calculations with various values of the angular distribution parameter β in the Moyer model show that β = 7.0 ± 0.5 would meet the CASIM results at most, especially regarding locations at which the values of the maximum dose equivalent occur. (author)
Energy Technology Data Exchange (ETDEWEB)
Carlen, Ida; Nikolopoulos, Anna; Isaeus, Martin (AquaBiota Water Research, Stockholm (SE))
2007-06-15
GIS grids (maps) of marine parameters were created using point data from previous site investigations in the Forsmark and Oskarshamn areas. The proportion of global radiation reaching the sea bottom in Forsmark and Oskarshamn was calculated in ArcView, using Secchi depth measurements and the digital elevation models for the respective area. The number of days per year when the incoming light exceeds 5 MJ/m2 at the bottom was then calculated using the result of the previous calculations together with measured global radiation. Existing modelled grid-point data on bottom and pelagic temperature for Forsmark were interpolated to create surface covering grids. Bottom and pelagic temperature grids for Oskarshamn were calculated using point measurements to achieve yearly averages for a few points and then using regressions with existing grids to create new maps. Phytoplankton primary production in Forsmark was calculated using point measurements of chlorophyll and irradiance, and a regression with a modelled grid of Secchi depth. Distribution of biomass of macrophyte communities in Forsmark and Oskarshamn was calculated using spatial modelling in GRASP, based on field data from previous surveys. Physical parameters such as those described above were used as predictor variables. Distribution of biomass of different functional groups of fish in Forsmark was calculated using spatial modelling based on previous surveys and with predictor variables such as physical parameters and results from macrophyte modelling. All results are presented as maps in the report. The quality of the modelled predictions varies as a consequence of the quality and amount of the input data, the ecology and knowledge of the predicted phenomena, and by the modelling technique used. A substantial part of the variation is not described by the models, which should be expected for biological modelling. Therefore, the resulting grids should be used with caution and with this uncertainty kept in mind. All
International Nuclear Information System (INIS)
Carlen, Ida; Nikolopoulos, Anna; Isaeus, Martin
2007-06-01
GIS grids (maps) of marine parameters were created using point data from previous site investigations in the Forsmark and Oskarshamn areas. The proportion of global radiation reaching the sea bottom in Forsmark and Oskarshamn was calculated in ArcView, using Secchi depth measurements and the digital elevation models for the respective area. The number of days per year when the incoming light exceeds 5 MJ/m2 at the bottom was then calculated using the result of the previous calculations together with measured global radiation. Existing modelled grid-point data on bottom and pelagic temperature for Forsmark were interpolated to create surface covering grids. Bottom and pelagic temperature grids for Oskarshamn were calculated using point measurements to achieve yearly averages for a few points and then using regressions with existing grids to create new maps. Phytoplankton primary production in Forsmark was calculated using point measurements of chlorophyll and irradiance, and a regression with a modelled grid of Secchi depth. Distribution of biomass of macrophyte communities in Forsmark and Oskarshamn was calculated using spatial modelling in GRASP, based on field data from previous surveys. Physical parameters such as those described above were used as predictor variables. Distribution of biomass of different functional groups of fish in Forsmark was calculated using spatial modelling based on previous surveys and with predictor variables such as physical parameters and results from macrophyte modelling. All results are presented as maps in the report. The quality of the modelled predictions varies as a consequence of the quality and amount of the input data, the ecology and knowledge of the predicted phenomena, and by the modelling technique used. A substantial part of the variation is not described by the models, which should be expected for biological modelling. Therefore, the resulting grids should be used with caution and with this uncertainty kept in mind. All
International Nuclear Information System (INIS)
Collins, E.D.; Bigelow, J.E.; Campbell, D.O.; King, L.J.; Knauer, J.B.
1980-01-01
Several chemical processing flowsheets were considered for the decontamination of high-activity-level water at the Three Mile Island (TMI) Unit 2. A zeolite ion exchange process was evaluated and recommended for absorption of the bulk of the highly radioactive cesium and strontium. Standard organic ion-exchange resins were selected to remove the remaining traces of radioactive nuclides (except tritium which cannot be removed by any practical process). Process conditions were evaluated using both synthetic, tracer-level solutions and samples of actual, high-activity level water from TMI Unit 2
International Nuclear Information System (INIS)
Padmanabhan, N.P.H.; Sridhar, U.
1993-01-01
Simulation was carried out using a beach sand beneficiation plant simulator software, SANDBEN, currently being developed in Indian School of Mines, Dhanbad, and the results were compared and analyzed with those obtained by actual pilot plant experiments on a beach sand sample from Bhimunipatnam deposit. The software is discussed and its capabilities and limitations are highlighted. An optimal preconcentrator flow-sheet for processing Bhimunipatnam beach sand was developed by simulation and using the results of the pilot plant experiments. (author). 13 refs., 2 tabs., 3 figs
Zhang, Zhen; Xia, Changliang; Yan, Yan; Geng, Qiang; Shi, Tingna
2017-08-01
Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff's law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell's equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.
Comparison study on models for calculation of NPP’s levelized unit electricity cost
International Nuclear Information System (INIS)
Nuryanti; Mochamad Nasrullah; Suparman
2014-01-01
Economic analysis that is generally done through the calculation of Levelized Unit Electricity Cost (LUEC) is crucial to be done prior to any investment decision on the nuclear power plant (NPP) project. There are several models that can be used to calculate LUEC, which are: R&D PT. PLN (Persero) Model, Mini G4ECONS model and Levelized Cost model. This study aimed to perform a comparison between the three models. Comparison technique was done by tracking the similarity used for each model and then given a case of LUEC calculation for SMR NPP 2 x 100 MW using these models. The result showed that the R&D PT. PLN (Persero) Model have a common principle with Mini G4ECONS model, which use Capital Recovery Factor (CRF) to discount the investment cost which eventually become annuity value along the life of plant. LUEC on both models is calculated by dividing the sum of the annual investment cost and the cost for operating NPP with an annual electricity production.While Levelized Cost model based on the annual cash flow. Total of annual costs and annual electricity production were discounted to the first year of construction in order to obtain the total discounted annual cost and the total discounted energy generation. LUEC was obtained by dividing both of the discounted values. LUEC calculations on the three models produce LUEC value, which are: 14.5942 cents US$/kWh for R&D PT. PLN (Persero) Model, 15.056 cents US$/kWh for Mini G4ECONs model and 14.240 cents US$/kWh for Levelized Cost model. (author)
Nuclear model calculations below 200 MeV and evaluation prospects
International Nuclear Information System (INIS)
Koning, A.J.; Bersillon, O.; Delaroche, J.P.
1994-08-01
A computational method is outlined for the quantum-mechanical prediction of the whole double-differential energy spectrum. Cross sections as calculated with the code system MINGUS are presented for (n,xn) and (p,xn) reactions on 208 Pb and 209 Bi. Our approach involves a dispersive optical model, comprehensive discrete state calculations, renormalized particle-hole state densities, a combined MSD/MSC model for pre-equilibrium reactions and compound nucleus calculations. The relation with the evaluation of nuclear data files is discussed. (orig.)
Thermal-hydraulic feedback model to calculate the neutronic cross-section in PWR reactions
International Nuclear Information System (INIS)
Santiago, Daniela Maiolino Norberto
2011-01-01
In neutronic codes,it is important to have a thermal-hydraulic feedback module. This module calculates the thermal-hydraulic feedback of the fuel, that feeds the neutronic cross sections. In the neutronic co de developed at PEN / COPPE / UFRJ, the fuel temperature is obtained through an empirical model. This work presents a physical model to calculate this temperature. We used the finite volume technique of discretized the equation of temperature distribution, while calculation the moderator coefficient of heat transfer, was carried out using the ASME table, and using some of their routines to our program. The model allows one to calculate an average radial temperature per node, since the thermal-hydraulic feedback must follow the conditions imposed by the neutronic code. The results were compared with to the empirical model. Our results show that for the fuel elements near periphery, the empirical model overestimates the temperature in the fuel, as compared to our model, which may indicate that the physical model is more appropriate to calculate the thermal-hydraulic feedback temperatures. The proposed model was validated by the neutronic simulator developed in the PEN / COPPE / UFRJ for analysis of PWR reactors. (author)
An investigation of fission models for high-energy radiation transport calculations
International Nuclear Information System (INIS)
Armstrong, T.W.; Cloth, P.; Filges, D.; Neef, R.D.
1983-07-01
An investigation of high-energy fission models for use in the HETC code has been made. The validation work has been directed checking the accuracy of the high-energy radiation transport computer code HETC to investigate the appropriate model for routine calculations, particularly for spallation neutron source applications. Model calculations are given in terms of neutron production, fission fragment energy release, and residual nuclei production for high-energy protons incident on thin uranium targets. The effect of the fission models on neutron production from thick uranium targets is also shown. (orig.)
International Nuclear Information System (INIS)
Thykier-Nielsen, S.
1980-07-01
A brief description is given of the model used at Risoe for calculating the consequences of releases of radioactive material to the atmosphere. The model is based on the Gaussian plume model, and it provides possibilities for calculation of: doses to individuals, collective doses, contamination of the ground, probability distribution of doses, and the consequences of doses for give dose-risk relationships. The model is implemented as a computer program PLUCON2, written in ALGOL for the Burroughs B6700 computer at Risoe. A short description of PLUCON2 is given. (author)
Energy Technology Data Exchange (ETDEWEB)
Yoon, Jihyung; Jung, Jae Won, E-mail: jungj@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858 (United States); Kim, Jong Oh [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States); Yeo, Inhwan [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92354 (United States)
2016-05-15
Purpose: To develop and evaluate a fast Monte Carlo (MC) dose calculation model of electronic portal imaging device (EPID) based on its effective atomic number modeling in the XVMC code. Methods: A previously developed EPID model, based on the XVMC code by density scaling of EPID structures, was modified by additionally considering effective atomic number (Z{sub eff}) of each structure and adopting a phase space file from the EGSnrc code. The model was tested under various homogeneous and heterogeneous phantoms and field sizes by comparing the calculations in the model with measurements in EPID. In order to better evaluate the model, the performance of the XVMC code was separately tested by comparing calculated dose to water with ion chamber (IC) array measurement in the plane of EPID. Results: In the EPID plane, calculated dose to water by the code showed agreement with IC measurements within 1.8%. The difference was averaged across the in-field regions of the acquired profiles for all field sizes and phantoms. The maximum point difference was 2.8%, affected by proximity of the maximum points to penumbra and MC noise. The EPID model showed agreement with measured EPID images within 1.3%. The maximum point difference was 1.9%. The difference dropped from the higher value of the code by employing the calibration that is dependent on field sizes and thicknesses for the conversion of calculated images to measured images. Thanks to the Z{sub eff} correction, the EPID model showed a linear trend of the calibration factors unlike those of the density-only-scaled model. The phase space file from the EGSnrc code sharpened penumbra profiles significantly, improving agreement of calculated profiles with measured profiles. Conclusions: Demonstrating high accuracy, the EPID model with the associated calibration system may be used for in vivo dosimetry of radiation therapy. Through this study, a MC model of EPID has been developed, and their performance has been rigorously
National Oceanic and Atmospheric Administration, Department of Commerce — Declination is calculated using the current International Geomagnetic Reference Field (IGRF) model. Declination is calculated using the current World Magnetic Model...
Comparison of results of experimental research with numerical calculations of a model one-sided seal
Directory of Open Access Journals (Sweden)
Joachimiak Damian
2015-06-01
Full Text Available Paper presents the results of experimental and numerical research of a model segment of a labyrinth seal for a different wear level. The analysis covers the extent of leakage and distribution of static pressure in the seal chambers and the planes upstream and downstream of the segment. The measurement data have been compared with the results of numerical calculations obtained using commercial software. Based on the flow conditions occurring in the area subjected to calculations, the size of the mesh defined by parameter y+ has been analyzed and the selection of the turbulence model has been described. The numerical calculations were based on the measurable thermodynamic parameters in the seal segments of steam turbines. The work contains a comparison of the mass flow and distribution of static pressure in the seal chambers obtained during the measurement and calculated numerically in a model segment of the seal of different level of wear.
Energy Technology Data Exchange (ETDEWEB)
Shripad T. Revankar; Nicholas R. Brown; Cheikhou Kane; Seungmin Oh
2010-05-01
The realization of the hydrogen as an energy carrier for future power sources relies on a practical method of producing hydrogen in large scale with no emission of green house gases. Hydrogen is an energy carrier which can be produced by a thermochemical water splitting process. The Sulfur-Iodine (SI) process is an example of a water splitting method using iodine and sulfur as recycling agents.
Energy Technology Data Exchange (ETDEWEB)
Jantzen, C. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Edwards, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Trivelpiece, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ramsey, W. G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-06-14
Control of the REDuction/OXidation (REDOX) state of glasses containing high concentrations of transition metals, such as High Level Waste (HLW) glasses, is critical in order to eliminate processing difficulties caused by overly reduced or overly oxidized melts. Operation of a HLW melter at Fe^{+2}/ΣFe ratios of between 0.09 and 0.33, retains radionuclides in the melt and thus the final glass. Specifically, long-lived radioactive ^{99}Tc species are less volatile in the reduced Tc^{4+} state as TcO_{2} than as NaTcO_{4} or Tc_{2}O_{7}, and ruthenium radionuclides in the reduced Ru^{4+} state are insoluble RuO_{2} in the melt which are not as volatile as NaRuO_{4} where the Ru is in the +7 oxidation state. Similarly, hazardous volatile Cr^{6+} occurs in oxidized melt pools as Na_{2}CrO_{4} or Na_{2}Cr_{2}O_{7}, while the Cr^{+3} state is less volatile and remains in the melt as NaCrO_{2} or precipitates as chrome rich spinels. The melter REDOX control balances the oxidants and reductants from the feed and from processing additives such as antifoam.
Formation of decontamination cost calculation model for severe accident consequence assessment
International Nuclear Information System (INIS)
Silva, Kampanart; Promping, Jiraporn; Okamoto, Koji; Ishiwatari, Yuki
2014-01-01
In previous studies, the authors developed an index “cost per severe accident” to perform a severe accident consequence assessment that can cover various kinds of accident consequences, namely health effects, economic, social and environmental impacts. Though decontamination cost was identified as a major component, it was taken into account using simple and conservative assumptions, which make it difficult to have further discussions. The decontamination cost calculation model was therefore reconsidered. 99 parameters were selected to take into account all decontamination-related issues, and the decontamination cost calculation model was formed. The distributions of all parameters were determined. A sensitivity analysis using the Morris method was performed in order to identify important parameters that have large influence on the cost per severe accident and large extent of interactions with other parameters. We identified 25 important parameters, and fixed most negligible parameters to the median of their distributions to form a simplified decontamination cost calculation model. Calculations of cost per severe accident with the full model (all parameters distributed), and with the simplified model were performed and compared. The differences of the cost per severe accident and its components were not significant, which ensure the validity of the simplified model. The simplified model is used to perform a full scope calculation of the cost per severe accident and compared with the previous study. The decontamination cost increased its importance significantly. (author)
Comparison of a semi-empirical method with some model codes for gamma-ray spectrum calculation
Energy Technology Data Exchange (ETDEWEB)
Sheng, Fan; Zhixiang, Zhao [Chinese Nuclear Data Center, Beijing, BJ (China)
1996-06-01
Gamma-ray spectra calculated by a semi-empirical method are compared with those calculated by the model codes such as GNASH, TNG, UNF and NDCP-1. The results of the calculations are discussed. (2 tabs., 3 figs.).
International Nuclear Information System (INIS)
Kljenak, I.; Mavko, B.; Babic, M.
2005-01-01
Full text of publication follows: The modelling and simulation of atmosphere mixing and stratification in nuclear power plant containments is a topic, which is currently being intensely investigated. With the increase of computer power, it has now become possible to model these phenomena with a local instantaneous description, using so-called Computational Fluid Dynamics (CFD) codes. However, calculations with these codes still take relatively long times. An alternative faster approach, which is also being applied, is to model nonhomogeneous atmosphere with lumped-parameter codes by dividing larger control volumes into smaller volumes, in which conditions are modelled as homogeneous. The flow between smaller volumes is modelled using one-dimensional approaches, which includes the prescription of flow loss coefficients. However, some authors have questioned this approach, as it appears that atmosphere stratification may sometimes be well simulated only by adjusting flow loss coefficients to adequate 'artificial' values that are case-dependent. To start the resolution of this issue, a modelling of nonhomogeneous atmosphere with a lumped-parameter code is proposed, where the subdivision of a large volume into smaller volumes is based on results of CFD simulations. The basic idea is to use the results of a CFD simulation to define regions, in which the flow velocities have roughly the same direction. These regions are then modelled as control volumes in a lumped-parameter model. In the proposed work, this procedure was applied to a simulation of an experiment of atmosphere mixing and stratification, which was performed in the TOSQAN facility. The facility is located at the Institut de Radioprotection et de Surete Nucleaire (IRSN) in Saclay (France) and consists of a cylindrical vessel (volume: 7 m3), in which gases are injected. In the experiment, which was also proposed for the OECD/NEA International Standard Problem No.47, air was initially present in the vessel, and
A musculoskeletal lumbar and thoracic model for calculation of joint kinetics in the spine
International Nuclear Information System (INIS)
Kim, Yong Cheol; Ta, Duc manh; Koo, Seung Bum; Jung Moon Ki
2016-01-01
The objective of this study was to develop a musculoskeletal spine model that allows relative movements in the thoracic spine for calculation of intra-discal forces in the lumbar and thoracic spine. The thoracic part of the spine model was composed of vertebrae and ribs connected with mechanical joints similar to anatomical joints. Three different muscle groups around the thoracic spine were inserted, along with eight muscle groups around the lumbar spine in the original model from AnyBody. The model was tested using joint kinematics data obtained from two normal subjects during spine flexion and extension, axial rotation and lateral bending motions beginning from a standing posture. Intra-discal forces between spine segments were calculated in a musculoskeletal simulation. The force at the L4-L5 joint was chosen to validate the model's prediction against the lumbar model in the original AnyBody model, which was previously validated against clinical data.
A musculoskeletal lumbar and thoracic model for calculation of joint kinetics in the spine
Energy Technology Data Exchange (ETDEWEB)
Kim, Yong Cheol; Ta, Duc manh; Koo, Seung Bum [Chung-Ang University, Seoul (Korea, Republic of); Jung Moon Ki [AnyBody Technology A/S, Aalborg (Denmark)
2016-06-15
The objective of this study was to develop a musculoskeletal spine model that allows relative movements in the thoracic spine for calculation of intra-discal forces in the lumbar and thoracic spine. The thoracic part of the spine model was composed of vertebrae and ribs connected with mechanical joints similar to anatomical joints. Three different muscle groups around the thoracic spine were inserted, along with eight muscle groups around the lumbar spine in the original model from AnyBody. The model was tested using joint kinematics data obtained from two normal subjects during spine flexion and extension, axial rotation and lateral bending motions beginning from a standing posture. Intra-discal forces between spine segments were calculated in a musculoskeletal simulation. The force at the L4-L5 joint was chosen to validate the model's prediction against the lumbar model in the original AnyBody model, which was previously validated against clinical data.
Directory of Open Access Journals (Sweden)
M. Ridolfi
2014-12-01
Full Text Available We review the main factors driving the calculation of the tangent height of spaceborne limb measurements: the ray-tracing method, the refractive index model and the assumed atmosphere. We find that commonly used ray tracing and refraction models are very accurate, at least in the mid-infrared. The factor with largest effect in the tangent height calculation is the assumed atmosphere. Using a climatological model in place of the real atmosphere may cause tangent height errors up to ± 200 m. Depending on the adopted retrieval scheme, these errors may have a significant impact on the derived profiles.
Power Loss Calculation and Thermal Modelling for a Three Phase Inverter Drive System
Directory of Open Access Journals (Sweden)
Z. Zhou
2005-12-01
Full Text Available Power losses calculation and thermal modelling for a three-phase inverter power system is presented in this paper. Aiming a long real time thermal simulation, an accurate average power losses calculation based on PWM reconstruction technique is proposed. For carrying out the thermal simulation, a compact thermal model for a three-phase inverter power module is built. The thermal interference of adjacent heat sources is analysed using 3D thermal simulation. The proposed model can provide accurate power losses with a large simulation time-step and suitable for a long real time thermal simulation for a three phase inverter drive system for hybrid vehicle applications.
International Nuclear Information System (INIS)
Oliveira, A.C.J.G. de; Andrade Lima, F.R. de
1989-01-01
The present work is an application of the perturbation theory (Matricial formalism) to a simplified two channels model, for sensitivity calculations in PWR cores. Expressions for some sensitivity coefficients of thermohydraulic interest were developed from the proposed model. The code CASNUR.FOR was written in FORTRAN to evaluate these sensitivity coefficients. The comparison between results obtained from the matrical formalism of pertubation theory with those obtained directly from the two channels model, makes evident the efficiency and potentiality of this perturbation method for nuclear reactor cores sensitivity calculations. (author) [pt
Model calculations of excitation functions of neutron-induced reactions on Rh
International Nuclear Information System (INIS)
Strohmaier, Brigitte
1995-01-01
Cross sections of neutron-induced reactions on 103 Rh have been calculated by means of the statistical model and the coupled-channels optical model for incident-neutron energies up to 30 MeV. The incentive for this study was a new measurement of the 103 Rh(n, n') 103m Rh cross section which will - together with the present calculations -enter into a dosimetry-reaction evaluation. The validation of the model parameters relied on nuclear-structure data as far as possible. (author)
A conceptual and calculational model for gas formation from impure calcined plutonium oxides
International Nuclear Information System (INIS)
Lyman, John L.; Eller, P. Gary
2000-01-01
Safe transport and storage of pure and impure plutonium oxides requires an understanding of processes that may generate or consume gases in a confined storage vessel. We have formulated conceptual and calculational models for gas formation from calcined materials. The conceptual model for impure calcined plutonium oxides is based on the data collected to date
3D Printing of Molecular Models with Calculated Geometries and p Orbital Isosurfaces
Carroll, Felix A.; Blauch, David N.
2017-01-01
3D printing was used to prepare models of the calculated geometries of unsaturated organic structures. Incorporation of p orbital isosurfaces into the models enables students in introductory organic chemistry courses to have hands-on experience with the concept of orbital alignment in strained and unstrained p systems.
Model calculations on LIS. II1. 2-, 3- and 7-substituted indanones
International Nuclear Information System (INIS)
Hofer, O.
1979-01-01
The space close to the coordination site of 1-indanone is modified systematically by placing alkyl groups of different bulkiness on C-2, C-3 and C-7, resp. The 1 H-LIS for the compounds are interpreted using the one site and two site model for carbonyl. Precautionary measures are discussed for both models to give reliable results in the calculation. (author)
MONNIE 2000: A description of a model to calculate environmental costs
International Nuclear Information System (INIS)
Hanemaaijer, A.H.; Kirkx, M.C.A.P.
2001-02-01
A new model (MONNIE 2000) was developed by the RIVM in the Netherlands in 2000 to calculate environmental costs on a macro level. The model, it's theoretical backgrounds and the technical aspects are described, making it attractive to both the user and the designer of the model. A user manual on how to calculate with the model is included. The basic principle of the model is the use of a harmonised method for calculating environmental costs, which provides the user with an output that can easily be compared with and used in other economic statistics and macro-economic models in the Netherlands. Input for the model are yearly figures on operational costs, investments and savings from environmental measures. With MONNIE 2000 calculated environmental costs per policy target group, economic sector and theme can be shown, With this model the burden of environmental measures on the economic sectors and the environmental expenditures of the government can be presented as well. MONNIE 2000 is developed in Visual Basic and by using Excel as input and output a user-friendly data exchange is realised. 12 refs
Inclusion of temperature dependence of fission barriers in statistical model calculations
International Nuclear Information System (INIS)
Newton, J.O.; Popescu, D.G.; Leigh, J.R.
1990-08-01
The temperature dependence of fission barriers has been interpolated from the results of recent theoretical calculations and included in the statistical model code PACE2. It is shown that the inclusion of temperature dependence causes significant changes to the values of the statistical model parameters deduced from fits to experimental data. 21 refs., 2 figs
On the applicability of nearly free electron model for resistivity calculations in liquid metals
International Nuclear Information System (INIS)
Gorecki, J.; Popielawski, J.
1982-09-01
The calculations of resistivity based on the nearly free electron model are presented for many noble and transition liquid metals. The triple ion correlation is included in resistivity formula according to SCQCA approximation. Two different methods for describing the conduction band are used. The problem of applicability of the nearly free electron model for different metals is discussed. (author)
A simple model for calculating the bulk modulus of the mixed ionic ...
Indian Academy of Sciences (India)
thermophysical properties, viz., bulk modulus, molecular force constant, reststrahlen fre- quency and Debye temperature using the three-body potential model. The calculated bulk modulus, from the TBPM model, for the pure end members (NH4Cl and NH4Br) are in agreement with the experimental values, as shown in ...
Validation of a model for calculating environmental doses caused by gamma emitters in the soil
International Nuclear Information System (INIS)
Ortega, X.; Rosell, J.R.; Dies, X.
1991-01-01
A model has been developed to calculate the absorbed dose rates caused by gamma emitters of both natural and artificial origin distributed in the soil. The model divides the soil into five compartments corresponding to layers situated at different depths, and assumes that the concentration of radionuclides is constant in each one of them. The calculations, following the model developed, are undertaken through a program which, based on the concentrations of the radionuclides in the different compartments, gives as a result the dose rate at a height of one metre above the ground caused by each radionuclide and the percentage this represents with respect to the total absorbed dose rate originating from this soil. The validity of the model has been checked in the case of sandy soils by comparing the exposure rates calculated for five sites with the experimental values obtained with an ionisation chamber. (author)
Diameter structure modeling and the calculation of plantation volume of black poplar clones
Directory of Open Access Journals (Sweden)
Andrašev Siniša
2004-01-01
Full Text Available A method of diameter structure modeling was applied in the calculation of plantation (stand volume of two black poplar clones in the section Aigeiros (Duby: 618 (Lux and S1-8. Diameter structure modeling by Weibull function makes it possible to calculate the plantation volume by volume line. Based on the comparison of the proposed method with the existing methods, the obtained error of plantation volume was less than 2%. Diameter structure modeling and the calculation of plantation volume by diameter structure model, by the regularity of diameter distribution, enables a better analysis of the production level and assortment structure and it can be used in the construction of yield and increment tables.
Recommendations on dose buildup factors used in models for calculating gamma doses for a plume
International Nuclear Information System (INIS)
Hedemann Jensen, P.; Thykier-Nielsen, S.
1980-09-01
Calculations of external γ-doses from radioactivity released to the atmosphere have been made using different dose buildup factor formulas. Some of the dose buildup factor formulas are used by the Nordic countries in their respective γ-dose models. A comparison of calculated γ-doses using these dose buildup factors shows that the γ-doses can be significantly dependent on the buildup factor formula used in the calculation. Increasing differences occur for increasing plume height, crosswind distance, and atmospheric stability and also for decreasing downwind distance. It is concluded that the most accurate γ-dose can be calculated by use of Capo's polynomial buildup factor formula. Capo-coefficients have been calculated and shown in this report for γ-energies below the original lower limit given by Capo. (author)
Skolubovich, Yuriy; Skolubovich, Aleksandr; Voitov, Evgeniy; Soppa, Mikhail; Chirkunov, Yuriy
2017-10-01
The article considers the current questions of technological modeling and calculation of the new facility for cleaning natural waters, the clarifier reactor for the optimal operating mode, which was developed in Novosibirsk State University of Architecture and Civil Engineering (SibSTRIN). A calculation technique based on well-known dependences of hydraulics is presented. A calculation example of a structure on experimental data is considered. The maximum possible rate of ascending flow of purified water was determined, based on the 24 hour clarification cycle. The fractional composition of the contact mass was determined with minimal expansion of contact mass layer, which ensured the elimination of stagnant zones. The clarification cycle duration was clarified by the parameters of technological modeling by recalculating maximum possible upward flow rate of clarified water. The thickness of the contact mass layer was determined. Likewise, clarification reactors can be calculated for any other lightening conditions.
Liu, Long; Liu, Wei
2018-04-01
A forward modeling and inversion algorithm is adopted in order to determine the water injection plan in the oilfield water injection network. The main idea of the algorithm is shown as follows: firstly, the oilfield water injection network is inversely calculated. The pumping station demand flow is calculated. Then, forward modeling calculation is carried out for judging whether all water injection wells meet the requirements of injection allocation or not. If all water injection wells meet the requirements of injection allocation, calculation is stopped, otherwise the demand injection allocation flow rate of certain step size is reduced aiming at water injection wells which do not meet requirements, and next iterative operation is started. It is not necessary to list the algorithm into water injection network system algorithm, which can be realized easily. Iterative method is used, which is suitable for computer programming. Experimental result shows that the algorithm is fast and accurate.
Research of coincidence method for calculation model of the specific detector
Energy Technology Data Exchange (ETDEWEB)
Guangchun, Hu; Suping, Liu; Jian, Gong [China Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry
2003-07-01
The physical size of specific detector is known normally, but production business is classified for some sizes that is concerned with the property of detector, such as the well diameter, well depth of detector and dead region. The surface source of even distribution and the sampling method of source particle isotropy sport have been established with the method of Monte Carlo, and gamma ray respond spectral with the {sup 152}Eu surface source been calculated. The experiment have been performed under the same conditions. Calculation and experiment results are compared with relative efficiency coincidence method and spectral similar degree coincidence method. According to comparison as a result, detector model is revised repeatedly to determine the calculation model of detector and to calculate efficiency of detector and spectra. (authors)
Calculations of higher twist distribution functions in the MIT bag model
International Nuclear Information System (INIS)
Signal, A.I.
1997-01-01
We calculate all twist-2, -3 and -4 parton distribution functions involving two quark correlations using the wave function of the MIT bag model. The distributions are evolved up to experimental scales and combined to give the various nucleon structure functions. Comparisons with recent experimental data on higher twist structure functions at moderate values of Q 2 give good agreement with the calculated structure functions. (orig.)
Proposal for a new CAPE-OPEN Object Model
Process simulation applications require the exchange of significant amounts of data between the flowsheet environment, unit operation model, and thermodynamic server. Packing and unpacking various data types and exchanging data using structured text-based architectures, including...
Kanematsu, Yusuke; Tachikawa, Masanori
2015-05-21
Multicomponent quantum mechanical (MC_QM) calculations with polarizable continuum model (PCM) have been tested against liquid (1)H NMR chemical shifts for a test set of 80 molecules. Improvement from conventional quantum mechanical calculations was achieved for MC_QM calculations. The advantage of the multicomponent scheme could be attributed to the geometrical change from the equilibrium geometry by the incorporation of the hydrogen nuclear quantum effect, while that of PCM can be attributed to the change of the electronic structure according to the polarization by solvent effects.
QEDMOD: Fortran program for calculating the model Lamb-shift operator
Shabaev, V. M.; Tupitsyn, I. I.; Yerokhin, V. A.
2018-02-01
We present Fortran package QEDMOD for computing the model QED operator hQED that can be used to account for the Lamb shift in accurate atomic-structure calculations. The package routines calculate the matrix elements of hQED with the user-specified one-electron wave functions. The operator can be used to calculate Lamb shift in many-electron atomic systems with a typical accuracy of few percent, either by evaluating the matrix element of hQED with the many-electron wave function, or by adding hQED to the Dirac-Coulomb-Breit Hamiltonian.
HgTe-CdTe phase diagrams calculation by RAS model
International Nuclear Information System (INIS)
Hady, A.A.A.
1986-11-01
The model of Regular Associated Solutions (RAS) for binary solution, which extended onto the ternary solution was used for Mercury-Cadnium-Tellurim phase diagrams calculations. The function of dissociation parameters is used here as a function of temperature and it is independent of composition. The ratio of mole fractions has a weak dependence on temperature and is not neglected. The calculated liquidus binary temperature and the experimental one are so fitted to give the best values of parameters used to calculate the HgTe-CdTe phase diagrams. (author)
SITE-94. Adaptation of mechanistic sorption models for performance assessment calculations
International Nuclear Information System (INIS)
Arthur, R.C.
1996-10-01
Sorption is considered in most predictive models of radionuclide transport in geologic systems. Most models simulate the effects of sorption in terms of empirical parameters, which however can be criticized because the data are only strictly valid under the experimental conditions at which they were measured. An alternative is to adopt a more mechanistic modeling framework based on recent advances in understanding the electrical properties of oxide mineral-water interfaces. It has recently been proposed that these 'surface-complexation' models may be directly applicable to natural systems. A possible approach for adapting mechanistic sorption models for use in performance assessments, using this 'surface-film' concept, is described in this report. Surface-acidity parameters in the Generalized Two-Layer surface complexation model are combined with surface-complexation constants for Np(V) sorption ob hydrous ferric oxide to derive an analytical model enabling direct calculation of corresponding intrinsic distribution coefficients as a function of pH, and Ca 2+ , Cl - , and HCO 3 - concentrations. The surface film concept is then used to calculate whole-rock distribution coefficients for Np(V) sorption by altered granitic rocks coexisting with a hypothetical, oxidized Aespoe groundwater. The calculated results suggest that the distribution coefficients for Np adsorption on these rocks could range from 10 to 100 ml/g. Independent estimates of K d for Np sorption in similar systems, based on an extensive review of experimental data, are consistent, though slightly conservative, with respect to the calculated values. 31 refs
A pencil beam dose calculation model for CyberKnife system
Energy Technology Data Exchange (ETDEWEB)
Liang, Bin; Li, Yongbao; Liu, Bo; Zhou, Fugen [Image Processing Center, Beihang University, Beijing 100191 (China); Xu, Shouping [Department of Radiation Oncology, PLA General Hospital, Beijing 100853 (China); Wu, Qiuwen, E-mail: Qiuwen.Wu@Duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)
2016-10-15
Purpose: CyberKnife system is initially equipped with fixed circular cones for stereotactic radiosurgery. Two dose calculation algorithms, Ray-Tracing and Monte Carlo, are available in the supplied treatment planning system. A multileaf collimator system was recently introduced in the latest generation of system, capable of arbitrarily shaped treatment field. The purpose of this study is to develop a model based dose calculation algorithm to better handle the lateral scatter in an irregularly shaped small field for the CyberKnife system. Methods: A pencil beam dose calculation algorithm widely used in linac based treatment planning system was modified. The kernel parameters and intensity profile were systematically determined by fitting to the commissioning data. The model was tuned using only a subset of measured data (4 out of 12 cones) and applied to all fixed circular cones for evaluation. The root mean square (RMS) of the difference between the measured and calculated tissue-phantom-ratios (TPRs) and off-center-ratio (OCR) was compared. Three cone size correction techniques were developed to better fit the OCRs at the penumbra region, which are further evaluated by the output factors (OFs). The pencil beam model was further validated against measurement data on the variable dodecagon-shaped Iris collimators and a half-beam blocked field. Comparison with Ray-Tracing and Monte Carlo methods was also performed on a lung SBRT case. Results: The RMS between the measured and calculated TPRs is 0.7% averaged for all cones, with the descending region at 0.5%. The RMSs of OCR at infield and outfield regions are both at 0.5%. The distance to agreement (DTA) at the OCR penumbra region is 0.2 mm. All three cone size correction models achieve the same improvement in OCR agreement, with the effective source shift model (SSM) preferred, due to their ability to predict more accurately the OF variations with the source to axis distance (SAD). In noncircular field validation
International Nuclear Information System (INIS)
Cliffe, K.A.; Morris, S.T.; Porter, J.D.
1998-05-01
NAMMU is a computer program for modelling groundwater flow and transport through porous media. This document provides an overview of the use of the program for geosphere modelling in performance assessment calculations and gives a detailed description of the program itself. The aim of the document is to give an indication of the grounds for having confidence in NAMMU as a performance assessment tool. In order to achieve this the following topics are discussed. The basic premises of the assessment approach and the purpose of and nature of the calculations that can be undertaken using NAMMU are outlined. The concepts of the validation of models and the considerations that can lead to increased confidence in models are described. The physical processes that can be modelled using NAMMU and the mathematical models and numerical techniques that are used to represent them are discussed in some detail. Finally, the grounds that would lead one to have confidence that NAMMU is fit for purpose are summarised
International Nuclear Information System (INIS)
Webb, G.A.M.; Grimwood, P.D.
1976-12-01
This report describes an oceanographic model which has been developed for the use in calculating the capacity of the oceans to accept radioactive wastes. One component is a relatively short-term diffusion model which is based on that described in an earlier report (Webb et al., NRPB-R14(1973)), but which has been generalised to some extent. Another component is a compartment model which is used to calculate long-term widespread water concentrations. This addition overcomes some of the short comings of the earlier diffusion model. Incorporation of radioactivity into deep ocean sediments is included in this long-term model as a removal mechanism. The combined model is used to provide a conservative (safe) estimate of the maximum concentrations of radioactivity in water as a function of time after the start of a continuous disposal operation. These results can then be used to assess the limiting capacity of an ocean to accept radioactive waste. (author)
International Nuclear Information System (INIS)
Schick, W.C. Jr.; Milani, S.; Duncombe, E.
1980-03-01
A model has been devised for incorporating into the thermal feedback procedure of the PDQ few-group diffusion theory computer program the explicit calculation of depletion and temperature dependent fuel-rod shrinkage and swelling at each mesh point. The model determines the effect on reactivity of the change in hydrogen concentration caused by the variation in coolant channel area as the rods contract and expand. The calculation of fuel temperature, and hence of Doppler-broadened cross sections, is improved by correcting the heat transfer coefficient of the fuel-clad gap for the effects of clad creep, fuel densification and swelling, and release of fission-product gases into the gap. An approximate calculation of clad stress is also included in the model
International Nuclear Information System (INIS)
Allam, Kh. A.
2017-01-01
In this work, a new methodology is developed based on Monte Carlo simulation for tunnels and mines external dose calculation. Tunnels external dose evaluation model of a cylindrical shape of finite thickness with an entrance and with or without exit. A photon transportation model was applied for exposure dose calculations. A new software based on Monte Carlo solution was designed and programmed using Delphi programming language. The variation of external dose due to radioactive nuclei in a mine tunnel and the corresponding experimental data lies in the range 7.3 19.9%. The variation of specific external dose rate with position in, tunnel building material density and composition were studied. The given new model has more flexible for real external dose in any cylindrical tunnel structure calculations. (authors)
Development of a model for the primary system CAREM reactor's stationary thermohydraulic calculation
International Nuclear Information System (INIS)
Gaspar, C.; Abbate, P.
1990-01-01
The ESCAREM program oriented to CAREM reactors' stationary thermohydraulic calculation is presented. As CAREM gives variations in relation to models for BWR (Boiling Water Reactors)/PWR (Pressurized Water Reactors) reactors, it was decided to develop a suitable model which allows to calculate: a) if the Steam Generator design is adequate to transfer the power required; b) the circulation flow that occurs in the Primary System; c) the temperature at the entrance (cool branch) and d) the contribution of each component to the pressure drop in the circulation connection. Results were verified against manual calculations and alternative numerical models. An experimental validation at the Thermohydraulic Essays Laboratory is suggested. A parametric analysis series is presented on CAREM 25 reactor, demonstrating operating conditions, at different power levels, as well as the influence of different design aspects. (Author) [es
International Nuclear Information System (INIS)
Honda, M.; Kajita, T.; Kasahara, K.; Midorikawa, S.; Sanuki, T.
2007-01-01
Using the 'modified DPMJET-III' model explained in the previous paper [T. Sanuki et al., preceding Article, Phys. Rev. D 75, 043005 (2007).], we calculate the atmospheric neutrino flux. The calculation scheme is almost the same as HKKM04 [M. Honda, T. Kajita, K. Kasahara, and S. Midorikawa, Phys. Rev. D 70, 043008 (2004).], but the usage of the 'virtual detector' is improved to reduce the error due to it. Then we study the uncertainty of the calculated atmospheric neutrino flux summarizing the uncertainties of individual components of the simulation. The uncertainty of K-production in the interaction model is estimated using other interaction models: FLUKA'97 and FRITIOF 7.02, and modifying them so that they also reproduce the atmospheric muon flux data correctly. The uncertainties of the flux ratio and zenith angle dependence of the atmospheric neutrino flux are also studied
Numerical calculation models of the elastoplastic response of a structure under seismic action
International Nuclear Information System (INIS)
Edjtemai, Nima.
1982-06-01
Two digital calculation models developed in this work have made it possible to analyze the exact dynamic behaviour of ductile structures with one or several degrees of liberty, during earthquakes. With the first model, response spectra were built in the linear and non-linear fields for different absorption and ductility values and two types of seismic accelerograms. The comparative study of these spectra made it possible to check the validity of certain hypotheses suggested for the construction of elastoplastic spectra from corresponding linear spectra. A simplified method of non-linear seismic calculation based on the modal analysis and the spectra of elastoplastic response was then applied to structures with a varying number of degrees of liberty. The results obtained in this manner were compared with those provided by an exact calculation provided by the second digital model developed by us [fr
Fission product model for lattice calculation of high conversion boiling water reactor
International Nuclear Information System (INIS)
Iijima, S.; Yoshida, T.; Yamamoto, T.
1988-01-01
A high precision fission product model for boiling water reactor (BWR) lattice calculation was developed, which consists of 45 nuclides to be treated explicitly and one nonsaturating pseudo nuclide. This model is applied to a high conversion BWR lattice calculation code. From a study based on a three-energy-group calculation of fission product poisoning due to full fission products and explicitly treated nuclides, the multigroup capture cross sections and the effective fission yields of the pseudo nuclide are determined, which do not depend on fuel types or reactor operating conditions for a good approximation. Apart from nuclear data uncertainties, the model and the derived pseudo nuclide constants would predict the fission product reactivity within an error of 0.1% Δk at high burnup
CLEAR: a model for the calculation of evacuation-time estimates in Emergency Planning Zones
International Nuclear Information System (INIS)
McLean, M.A.; Moeller, M.P.; Desrosiers, A.E.
1983-01-01
This paper describes the methodology and application of the computer model CLEAR (Calculates Logical Evacuation And Response) which estimates the time required for a specific population density and distribution to evacuate an area using a specific transportation network. The CLEAR model simulates vehicle departure and movement on a transportation network according to the conditions and consequences of traffice flow. These include handling vehicles at intersecting road segments, calculating the velocity of travel on a road segment as a function of its vehicle density, and accounting for the delay of vehicles in traffice queues. The program also models the distribution of times required by individuals to prepare for an evacuation. CLEAR can calculate realistic evacuation time estimates using site specific data and can identify troublesome areas within an Emergency Planning Zone
Weck, Philippe F; Kim, Eunja; Wang, Yifeng; Kruichak, Jessica N; Mills, Melissa M; Matteo, Edward N; Pellenq, Roland J-M
2017-08-01
Molecular structures of kerogen control hydrocarbon production in unconventional reservoirs. Significant progress has been made in developing model representations of various kerogen structures. These models have been widely used for the prediction of gas adsorption and migration in shale matrix. However, using density functional perturbation theory (DFPT) calculations and vibrational spectroscopic measurements, we here show that a large gap may still remain between the existing model representations and actual kerogen structures, therefore calling for new model development. Using DFPT, we calculated Fourier transform infrared (FTIR) spectra for six most widely used kerogen structure models. The computed spectra were then systematically compared to the FTIR absorption spectra collected for kerogen samples isolated from Mancos, Woodford and Marcellus formations representing a wide range of kerogen origin and maturation conditions. Limited agreement between the model predictions and the measurements highlights that the existing kerogen models may still miss some key features in structural representation. A combination of DFPT calculations with spectroscopic measurements may provide a useful diagnostic tool for assessing the adequacy of a proposed structural model as well as for future model development. This approach may eventually help develop comprehensive infrared (IR)-fingerprints for tracing kerogen evolution.
Energy Technology Data Exchange (ETDEWEB)
Sukegawa, Takenori; Ohshima, Soichiro; Shiraishi, Kunio; Yanagihara, Satoshi [Department of Decommissioning and Waste Management, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai Ibaraki (Japan)
1999-02-01
Labor-hours necessary for dismantling activities are generally estimated based on experience, for example, as a form of unit productivity factors such as the relationship between labor-hours and weight of components dismantled which were obtained by actual dismantling activities. The project management data calculation models together with unit productivity factors for basic dismantling work activities were developed by analyzing the data obtained from the Japan Power Demonstration Reactor (JPDR) dismantling project, which will be applicable to estimation of labor-hours in various dismantling conditions. Typical work breakdown structures were also prepared by categorizing repeatable basic dismantling work activities for effective planning of dismantling activities. The labor-hours for dismantling the JPDR components and structures were calculated by using the code system for management of reactor decommissioning (COSMARD), in which the work breakdown structures and the calculation models were contained. It was confirmed that the labor-hours could be easily estimated by COSMARD through the calculations. This report describes the labor-hour calculation models and application of these models to COSMARD. (author)
Azimi, Ehsan; Behrad, Alireza; Ghaznavi-Ghoushchi, Mohammad Bagher; Shanbehzadeh, Jamshid
2016-11-01
The projective model is an important mapping function for the calculation of global transformation between two images. However, its hardware implementation is challenging because of a large number of coefficients with different required precisions for fixed point representation. A VLSI hardware architecture is proposed for the calculation of a global projective model between input and reference images and refining false matches using random sample consensus (RANSAC) algorithm. To make the hardware implementation feasible, it is proved that the calculation of the projective model can be divided into four submodels comprising two translations, an affine model and a simpler projective mapping. This approach makes the hardware implementation feasible and considerably reduces the required number of bits for fixed point representation of model coefficients and intermediate variables. The proposed hardware architecture for the calculation of a global projective model using the RANSAC algorithm was implemented using Verilog hardware description language and the functionality of the design was validated through several experiments. The proposed architecture was synthesized by using an application-specific integrated circuit digital design flow utilizing 180-nm CMOS technology as well as a Virtex-6 field programmable gate array. Experimental results confirm the efficiency of the proposed hardware architecture in comparison with software implementation.
Application of the mathematical modelling and human phantoms for calculation of the organ doses
International Nuclear Information System (INIS)
Kluson, J.; Cechak, T.
2005-01-01
Increasing power of the computers hardware and new versions of the software for the radiation transport simulation and modelling of the complex experimental setups and geometrical arrangement enable to dramatically improve calculation of organ or target volume doses ( dose distributions) in the wide field of medical physics and radiation protection applications. Increase of computers memory and new software features makes it possible to use not only analytical (mathematical) phantoms but also allow constructing the voxel models of human or phantoms with voxels fine enough (e.g. 1·1·1 mm) to represent all required details. CT data can be used for the description of such voxel model geometry .Advanced scoring methods are available in the new software versions. Contribution gives the overview of such new possibilities in the modelling and doses calculations, discusses the simulation/approximation of the dosimetric quantities ( especially dose ) and calculated data interpretation. Some examples of application and demonstrations will be shown, compared and discussed. Present computational tools enables to calculate organ or target volumes doses with new quality of large voxel models/phantoms (including CT based patient specific model ), approximating the human body with high precision. Due to these features has more and more importance and use in the fields of medical and radiological physics, radiation protection, etc. (authors)
A model for calculating hourly global solar radiation from satellite data in the tropics
International Nuclear Information System (INIS)
Janjai, S.; Pankaew, P.; Laksanaboonsong, J.
2009-01-01
A model for calculating global solar radiation from geostationary satellite data is presented. The model is designed to calculate the monthly average hourly global radiation in the tropics with high aerosol load. This model represents a physical relation between the earth-atmospheric albedo derived from GMS5 satellite data and the absorption and scattering coefficients of various atmospheric constituents. The absorption of solar radiation by water vapour which is important for the tropics, was calculated from ambient temperature and relative humidity. The relationship between the visibility and solar radiation depletion due to aerosols was developed for a high aerosol load environment. This relationship was used to calculate solar radiation depletion by aerosols in the model. The total column ozone from TOMS/EP satellite was employed for the determination of solar radiation absorbed by ozone. Solar radiation from four pyranometer stations was used to formulate the relationship between the satellite band earth-atmospheric albedo and broadband earth-atmospheric albedo required by the model. To test its performance, the model was used to compute the monthly average hourly global radiation at 25 solar radiation monitoring stations in tropical areas in Thailand. It was found that the values of monthly average of hourly global radiations calculated from the model were in good agreement with those obtained from the measurements, with the root mean square difference of 10%. After the validation the model was employed to generate hourly solar radiation maps of Thailand. These maps reveal the diurnal and season variation of solar radiation over the country.
A model for calculating hourly global solar radiation from satellite data in the tropics
Energy Technology Data Exchange (ETDEWEB)
Janjai, S.; Pankaew, P.; Laksanaboonsong, J. [Solar Energy Research Laboratory, Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand)
2009-09-15
A model for calculating global solar radiation from geostationary satellite data is presented. The model is designed to calculate the monthly average hourly global radiation in the tropics with high aerosol load. This model represents a physical relation between the earth-atmospheric albedo derived from GMS5 satellite data and the absorption and scattering coefficients of various atmospheric constituents. The absorption of solar radiation by water vapour which is important for the tropics, was calculated from ambient temperature and relative humidity. The relationship between the visibility and solar radiation depletion due to aerosols was developed for a high aerosol load environment. This relationship was used to calculate solar radiation depletion by aerosols in the model. The total column ozone from TOMS/EP satellite was employed for the determination of solar radiation absorbed by ozone. Solar radiation from four pyranometer stations was used to formulate the relationship between the satellite band earth-atmospheric albedo and broadband earth-atmospheric albedo required by the model. To test its performance, the model was used to compute the monthly average hourly global radiation at 25 solar radiation monitoring stations in tropical areas in Thailand. It was found that the values of monthly average of hourly global radiations calculated from the model were in good agreement with those obtained from the measurements, with the root mean square difference of 10%. After the validation the model was employed to generate hourly solar radiation maps of Thailand. These maps reveal the diurnal and season variation of solar radiation over the country. (author)
Half-life calculation of one-proton emitters with a shell model potential
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, M. M.; Duarte, S. B. [Centro Brasileiro de Pesquisas Fisicas-CBPF/MCT Rua Dr. Xavier Sigaud, 150, 22290-180, Rio de Janeiro-RJ (Brazil); Teruya, N. [Departamento de Fisica, Universidade Federal da Paraiba - UFPB Campus de Joao Pessoa, 58051-970, Joao Pessoa - PB (Brazil)
2013-03-25
The accumulated amount of data for half-lives of proton emitters still remains a challenge to the ability of nuclear models to reproduce them consistently. These nuclei are far from beta stability line in a region where the validity of current nuclear models is not guaranteed. A nuclear shell model is introduced to the calculation of the nuclear barrier of less deformed proton emitters. The predictions using the proposed model are in good agreement with the data, with the advantage of have used only a single parameter in the model.
A calculation of the ZH → γ H decay in the Littlest Higgs Model
International Nuclear Information System (INIS)
Aranda, J I; Ramirez-Zavaleta, F; Tututi, E S; Cortés-Maldonado, I
2016-01-01
New heavy neutral gauge bosons are predicted in many extensions of the Standard Model, those new bosons are associated with additional gauge symmetries. We present a preliminary calculation of the branching ratio decay for heavy neutral gauge bosons ( Z h ) into γ H in the most popular version of the Little Higgs models. The calculation involves the main contributions at one-loop level induced by fermions, scalars and gauge bosons. Preliminary results show a very suppressed branching ratio of the order of 10 -6 . (paper)
Calculation of the band structure of 2d conducting polymers using the network model
International Nuclear Information System (INIS)
Sabra, M. K.; Suman, H.
2007-01-01
the network model has been used to calculate the band structure the gap energy and Fermi level of conducting polymers in two dimensions. For this purpose, a geometrical classification of possible polymer chains configurations in two dimensions has been introduced leading to a classification of the unit cells based on the number of bonds in them. The model has been applied to graphite in 2D, represented by a three bonds unit cell, and, as a new case, the anti-parallel Polyacetylene chains (PA) in two dimensions, represented by a unit cell with four bons. The results are in good agreement with the first principles calculations. (author)
Numerical calculation of flashing from long pipes using a two-field model
International Nuclear Information System (INIS)
Rivard, W.C.; Torrey, M.D.
1976-05-01
A two-field model for two-phase flows, in which the vapor and liquid phases have different densities, velocities, and temperatures, has been used to calculate the flashing of water from long pipes. The IMF (Implicit Multifield) technique is used to numerically solve the transient equations that govern the dynamics of each phase. The flow physics is described with finite rate phase transitions, interfacial friction, heat transfer, pipe wall friction, and appropriate state equations. The results of the calculations are compared with measured histories of pressure, temperature, and void fraction. A parameter study indicates the relative sensitivity of the results to the various physical models that are used
Numerical calculation of flashing from long pipes using a two-field model
International Nuclear Information System (INIS)
Rivard, W.C.; Torrey, M.D.
1975-11-01
A two-field model for two-phase flows, in which the vapor and liquid phases have different densities, velocities, and temperatures, has been used to calculate the flashing of water from long pipes. The IMF (Implicit Multifield) technique is used to numerically solve the transient equations that govern the dynamics of each phase. The flow physics is described with finite rate phase transitions, interfacial friction, heat transfer, pipe wall friction, and appropriate state equations. The results of the calculations are compared with measured histories of pressure, temperature, and void fraction. A parameter study indicates the relative sensitivity of the results to the various physical models that are used
Recoilless fractions calculated with the nearest-neighbour interaction model by Kagan and Maslow
Kemerink, G. J.; Pleiter, F.
1986-08-01
The recoilless fraction is calculated for a number of Mössbauer atoms that are natural constituents of HfC, TaC, NdSb, FeO, NiO, EuO, EuS, EuSe, EuTe, SnTe, PbTe and CsF. The calculations are based on a model developed by Kagan and Maslow for binary compounds with rocksalt structure. With the exception of SnTe and, to a lesser extent, PbTe, the results are in reasonable agreement with the available experimental data and values derived from other models.
International Nuclear Information System (INIS)
Nielsen, S.P.; Gryning, S.E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.
1984-01-01
The paper presents work from a series of atmospheric dispersion experiments in May 1981 at the Ringhals nuclear power plant in Sweden. The aim of the project was to obtain short-term observations of concentrations and gamma-ray exposures from stack effluents and to compare these results with corresponding values calculated from computer models. Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released from a 110-m stack and detected at ground level downwind at distances of 3-4 km. Calculations were made with two Gaussian plume models: PLUCON developed at Riso National Laboratory and UNIDOSE developed at Studsvik Energiteknik AB. (orig.)
Comparison of turbulence models for numerical calculation of airflow in an annex 20 room
DEFF Research Database (Denmark)
Voigt, Lars P. K.
2000-01-01
The report deals with 2-D numerical calculation of room airflow in an isothermal annex 20 room. The report documents the ability of the flow solver EllipSys2D to give results in good agreement with measurements for the specified test case. The flow solver is a finite volume code solving the Reyno.......Applying theory for a two-dimensional wall jet, measurements are compared with calculated values of the turbulent kinetic energy....... the Reynolds Averaged Navier Stokes equations.Five two-equation turbulence models were tested. These are the standard k-epsilon model, the low-Reynolds number k-epison model by Launder & Sharma, the k-omega model by Wilcox, the k-omega baseline (BSL) model by Menter and the k-omega Shear Stress Transport (SST...
DEFF Research Database (Denmark)
Mattsson, T.R.; Wahnström, G.; Bengtsson, L.
1997-01-01
First-principles density-functional calculations of hydrogen adsorption on the Ni (001) surface have been performed in order to get a better understanding of adsorption and diffusion of hydrogen on metal surfaces. We find good agreement with experiments for the adsorption energy, binding distance...
International Nuclear Information System (INIS)
Lu Xiaogang; Selleby, Malin; Sundman, Bo
2007-01-01
The thermal expansivities and heat capacities of MX (M = Ti, Zr, Hf, V, Nb, Ta; X = C, N) carbides and nitrides with NaCl structure were calculated using the Debye-Grueneisen model combined with ab initio calculations. Two different approximations for the Grueneisen parameter γ were used in the Debye-Grueneisen model, i.e. the expressions proposed by Slater and by Dugdale and MacDonald. The thermal electronic contribution was evaluated from ab initio calculations of the electronic density of states. The calculated results were compared with CALPHAD assessments and experimental data. It was found that the calculations using the Dugdale-MacDonald γ can account for most of the experimental data. By fitting experimental heat capacity and thermal expansivity data below the Debye temperatures, an estimation of Poisson's ratio was obtained and Young's and shear moduli were evaluated. In order to reach a reasonable agreement with experimental data, it was necessary to use the logarithmic averaged mass of the constituent atoms. The agreements between the calculated and the experimental values for the bulk and Young's moduli are generally better than the agreement for shear modulus
Water-Exit Process Modeling and Added-Mass Calculation of the Submarine-Launched Missile
Directory of Open Access Journals (Sweden)
Yang Jian
2017-11-01
Full Text Available In the process that the submarine-launched missile exits the water, there is the complex fluid solid coupling phenomenon. Therefore, it is difficult to establish the accurate water-exit dynamic model. In the paper, according to the characteristics of the water-exit motion, based on the traditional method of added mass, considering the added mass changing rate, the water-exit dynamic model is established. And with help of the CFX fluid simulation software, a new calculation method of the added mass that is suit for submarine-launched missile is proposed, which can effectively solve the problem of fluid solid coupling in modeling process. Then by the new calculation method, the change law of the added mass in water-exit process of the missile is obtained. In simulated analysis, for the water-exit process of the missile, by comparing the results of the numerical simulation and the calculation of theoretical model, the effectiveness of the new added mass calculation method and the accuracy of the water-exit dynamic model that considers the added mass changing rate are verified.
Unified description of pf-shell nuclei by the Monte Carlo shell model calculations
Energy Technology Data Exchange (ETDEWEB)
Mizusaki, Takahiro; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Honma, Michio
1998-03-01
The attempts to solve shell model by new methods are briefed. The shell model calculation by quantum Monte Carlo diagonalization which was proposed by the authors is a more practical method, and it became to be known that it can solve the problem with sufficiently good accuracy. As to the treatment of angular momentum, in the method of the authors, deformed Slater determinant is used as the basis, therefore, for making angular momentum into the peculiar state, projected operator is used. The space determined dynamically is treated mainly stochastically, and the energy of the multibody by the basis formed as the result is evaluated and selectively adopted. The symmetry is discussed, and the method of decomposing shell model space into dynamically determined space and the product of spin and isospin spaces was devised. The calculation processes are shown with the example of {sup 50}Mn nuclei. The calculation of the level structure of {sup 48}Cr with known exact energy can be done with the accuracy of peculiar absolute energy value within 200 keV. {sup 56}Ni nuclei are the self-conjugate nuclei of Z=N=28. The results of the shell model calculation of {sup 56}Ni nucleus structure by using the interactions of nuclear models are reported. (K.I.)
Hydroelastic model of PWR reactor internals SAFRAN 1 - Validation of a vibration calculation method
International Nuclear Information System (INIS)
Epstein, A.; Gibert, R.J.; Jeanpierre, F.; Livolant, M.
1978-01-01
The SAFRAN 1 test loop consists of an hydroelastic similitude of a 1/8 scale model of a 3 loop P.W.R. Vibrations of the main internals (thermal shield and core barrel) and pressure fluctuations in water thin sections between vessel and internals, and in inlet and outlet pipes, have been measured. The calculation method consists of: an evaluation of the main vibration and acoustic sources owing to the flow (unsteady jet impingement on the core barrel, turbulent flow in a water thin section). A calculation of the internal modal parameters taking into account the inertial effects of fluid (the computer codes AQUAMODE and TRISTANA have been used). A calculation of the acoustic response of the circuit (the computer code VIBRAPHONE has been used). The good agreement between the calculation and the experimental results allows using this method with better security for the prediction of the vibration levels of full scale P.W.R. internals
Analytical model for calculation of the thermo hydraulic parameters in a fuel rod assembly
Energy Technology Data Exchange (ETDEWEB)
Cesna, B., E-mail: benas@mail.lei.l [Lithuanian Energy Institute, Laboratory of Nuclear Installation Safety, Breslaujos g. 3, LT-44403 Kaunas (Lithuania)
2010-11-15
Research highlights: {yields} Proposed calculation model can be used for rapid calculation of the bundles with rods spaced by wire wrapping or honey type spacer grids. {yields} Model estimate three flow cross mixture mechanisms. {yields} Program DARS is enable to analyses experimental results. - Abstract: The paper presents the procedure of the cellular calculation of thermo hydraulic parameters of a single-phase gas flow in a fuel rod assembly. The procedure is implemented in the DARS program. The program is intended for calculation of the distribution of the gaseous coolant parameters and wall temperatures in case of arbitrary, geometrically specified, arrangement of the rods in fuel assembly and in case of arbitrary, functionally specified in space, heat release in the rods. In mathematical model the flow cross-section of the channel of intricate shape is conventionally divided to elementary cells formed by straight lines, which connect the centers of rods. Within the limits of a single cell the coolant parameters and the temperature of the corresponding part of the rod surface are assumed constant. The entire fuel assembly is viewed as a system of parallel interconnected channels. Program DARS is illustrated by calculation of a temperature mode of 85-rod assembly with spacers of wire wrapping on the rods.
Energy Technology Data Exchange (ETDEWEB)
Sanchidrian, Jose A.; Lopez, Lina M. [Universidad Politecnica de Madrid - E.T.S.I. Minas, Rios Rosas 21, E-28003 Madrid (Spain)
2006-02-15
The energy delivered by explosives is described by means of the useful expansion work along the isentrope of the detonation products. A thermodynamic code (W-DETCOM) is used, in which a partial reaction model has been implemented. In this model, the reacted fraction of the explosive in the detonation state is used as a fitting factor so that the calculated detonation velocity meets the experimental value. Calculations based on such a model have been carried out for a number of commercial explosives of ANFO and emulsion types. The BKW (Becker-Kistiakowsky-Wilson) equation of state is used for the detonation gases with the Sandia parameter set (BKWS). The energy delivered in the expansion (useful work) is calculated, and the values obtained are compared with the Gurney energies from cylinder test data at various expansion ratios. The expansion work values obtained are much more realistic than those from an ideal detonation calculation and, in most cases, the values predicted by the calculation are in good agreement with the experimental ones. (Abstract Copyright [2006], Wiley Periodicals, Inc.)
International Nuclear Information System (INIS)
Birdsell, K.H.; Campbell, K.; Eggert, K.G.; Travis, B.J.
1989-01-01
This paper presents preliminary transport calculations for radionuclide movement at Yucca Mountain using preliminary data for mineral distributions, retardation parameter distributions, and hypothetical recharge scenarios. These calculations are not performance assessments, but are used to study the effectiveness of the geochemical barriers at the site at mechanistic level. The preliminary calculations presented have many shortcomings and should be viewed only as a demonstration of the modeling methodology. The simulations were run with TRACRN, a finite-difference porous flow and radionuclide transport code developed for the Yucca Mountain Project. Approximately 30,000 finite-difference nodes are used to represent the unsaturated and saturated zones underlying the repository in three dimensions. Sorption ratios for the radionuclides modeled are assumed to be functions of mineralogic assemblages of the underlying rock. These transport calculations present a representative radionuclide cation, 135 Cs and anion, 99 Tc. The effects on transport of many of the processes thought to be active at Yucca Mountain may be examined using this approach. The model provides a method for examining the integration of flow scenarios, transport, and retardation processes as currently understood for the site. It will also form the basis for estimates of the sensitivity of transport calculations to retardation processes. 11 refs., 17 figs., 1 tab
Energy Technology Data Exchange (ETDEWEB)
Murata, Isao [Osaka Univ., Suita (Japan); Mori, Takamasa; Nakagawa, Masayuki; Itakura, Hirofumi
1996-03-01
The method to calculate neutronics parameters of a core composed of randomly distributed spherical fuels has been developed based on a statistical geometry model with a continuous energy Monte Carlo method. This method was implemented in a general purpose Monte Carlo code MCNP, and a new code MCNP-CFP had been developed. This paper describes the model and method how to use it and the validation results. In the Monte Carlo calculation, the location of a spherical fuel is sampled probabilistically along the particle flight path from the spatial probability distribution of spherical fuels, called nearest neighbor distribution (NND). This sampling method was validated through the following two comparisons: (1) Calculations of inventory of coated fuel particles (CFPs) in a fuel compact by both track length estimator and direct evaluation method, and (2) Criticality calculations for ordered packed geometries. This method was also confined by applying to an analysis of the critical assembly experiment at VHTRC. The method established in the present study is quite unique so as to a probabilistic model of the geometry with a great number of spherical fuels distributed randomly. Realizing the speed-up by vector or parallel computations in future, it is expected to be widely used in calculation of a nuclear reactor core, especially HTGR cores. (author).
Program realization of mathematical model of kinetostatical calculation of flat lever mechanisms
Directory of Open Access Journals (Sweden)
M. A. Vasechkin
2016-01-01
Full Text Available Global computerization determined the dominant position of the analytical methods for the study of mechanisms. As a result, kinetostatics analysis of mechanisms using software packages is an important part of scientific and practical activities of engineers and designers. Therefore, software implementation of mathematical models kinetostatical calculating mechanisms is of practical interest. The mathematical model obtained in [1]. In the language of Turbo Pascal developed a computer procedure that calculates the forces in kinematic pairs in groups Assur (GA and a balancing force at the primary level. Before use appropriate computational procedures it is necessary to know all external forces and moments acting on the GA and to determine the inertial forces and moments of inertia forces. The process of calculations and constructions of the provisions of the mechanism can be summarized as follows. Organized cycle in which to calculate the position of an initial link of the mechanism. Calculate the position of the remaining links of the mechanism by referring to relevant procedures module DIADA in GA [2,3]. Using the graphics mode of the computer displaying on the display the position of the mechanism. The computed inertial forces and moments of inertia forces. Turning to the corresponding procedures of the module, calculated all the forces in kinematic pairs and the balancing force at the primary level. In each kinematic pair build forces and their direction with the help of simple graphical procedures. The magnitude of these forces and their direction are displayed in a special window with text mode. This work contains listings of the test programs MyTеst, is an example of using computing capabilities of the developed module. As a check on the calculation procedures of module in the program is reproduced an example of calculating the balancing forces according to the method of Zhukovsky (Zhukovsky lever.
Microscopic calculation of level densities: the shell model Monte Carlo approach
International Nuclear Information System (INIS)
Alhassid, Yoram
2012-01-01
The shell model Monte Carlo (SMMC) approach provides a powerful technique for the microscopic calculation of level densities in model spaces that are many orders of magnitude larger than those that can be treated by conventional methods. We discuss a number of developments: (i) Spin distribution. We used a spin projection method to calculate the exact spin distribution of energy levels as a function of excitation energy. In even-even nuclei we find an odd-even staggering effect (in spin). Our results were confirmed in recent analysis of experimental data. (ii) Heavy nuclei. The SMMC approach was extended to heavy nuclei. We have studied the crossover between vibrational and rotational collectivity in families of samarium and neodymium isotopes in model spaces of dimension approx. 10 29 . We find good agreement with experimental results for both state densities and 2 > (where J is the total spin). (iii) Collective enhancement factors. We have calculated microscopically the vibrational and rotational enhancement factors of level densities versus excitation energy. We find that the decay of these enhancement factors in heavy nuclei is correlated with the pairing and shape phase transitions. (iv) Odd-even and odd-odd nuclei. The projection on an odd number of particles leads to a sign problem in SMMC. We discuss a novel method to calculate state densities in odd-even and odd-odd nuclei despite the sign problem. (v) State densities versus level densities. The SMMC approach has been used extensively to calculate state densities. However, experiments often measure level densities (where levels are counted without including their spin degeneracies.) A spin projection method enables us to also calculate level densities in SMMC. We have calculated the SMMC level density of 162 Dy and found it to agree well with experiments
A single-source photon source model of a linear accelerator for Monte Carlo dose calculation.
Nwankwo, Obioma; Glatting, Gerhard; Wenz, Frederik; Fleckenstein, Jens
2017-01-01
To introduce a new method of deriving a virtual source model (VSM) of a linear accelerator photon beam from a phase space file (PSF) for Monte Carlo (MC) dose calculation. A PSF of a 6 MV photon beam was generated by simulating the interactions of primary electrons with the relevant geometries of a Synergy linear accelerator (Elekta AB, Stockholm, Sweden) and recording the particles that reach a plane 16 cm downstream the electron source. Probability distribution functions (PDFs) for particle positions and energies were derived from the analysis of the PSF. These PDFs were implemented in the VSM using inverse transform sampling. To model particle directions, the phase space plane was divided into a regular square grid. Each element of the grid corresponds to an area of 1 mm2 in the phase space plane. The average direction cosines, Pearson correlation coefficient (PCC) between photon energies and their direction cosines, as well as the PCC between the direction cosines were calculated for each grid element. Weighted polynomial surfaces were then fitted to these 2D data. The weights are used to correct for heteroscedasticity across the phase space bins. The directions of the particles created by the VSM were calculated from these fitted functions. The VSM was validated against the PSF by comparing the doses calculated by the two methods for different square field sizes. The comparisons were performed with profile and gamma analyses. The doses calculated with the PSF and VSM agree to within 3% /1 mm (>95% pixel pass rate) for the evaluated fields. A new method of deriving a virtual photon source model of a linear accelerator from a PSF file for MC dose calculation was developed. Validation results show that the doses calculated with the VSM and the PSF agree to within 3% /1 mm.
A single-source photon source model of a linear accelerator for Monte Carlo dose calculation.
Directory of Open Access Journals (Sweden)
Obioma Nwankwo
Full Text Available To introduce a new method of deriving a virtual source model (VSM of a linear accelerator photon beam from a phase space file (PSF for Monte Carlo (MC dose calculation.A PSF of a 6 MV photon beam was generated by simulating the interactions of primary electrons with the relevant geometries of a Synergy linear accelerator (Elekta AB, Stockholm, Sweden and recording the particles that reach a plane 16 cm downstream the electron source. Probability distribution functions (PDFs for particle positions and energies were derived from the analysis of the PSF. These PDFs were implemented in the VSM using inverse transform sampling. To model particle directions, the phase space plane was divided into a regular square grid. Each element of the grid corresponds to an area of 1 mm2 in the phase space plane. The average direction cosines, Pearson correlation coefficient (PCC between photon energies and their direction cosines, as well as the PCC between the direction cosines were calculated for each grid element. Weighted polynomial surfaces were then fitted to these 2D data. The weights are used to correct for heteroscedasticity across the phase space bins. The directions of the particles created by the VSM were calculated from these fitted functions. The VSM was validated against the PSF by comparing the doses calculated by the two methods for different square field sizes. The comparisons were performed with profile and gamma analyses.The doses calculated with the PSF and VSM agree to within 3% /1 mm (>95% pixel pass rate for the evaluated fields.A new method of deriving a virtual photon source model of a linear accelerator from a PSF file for MC dose calculation was developed. Validation results show that the doses calculated with the VSM and the PSF agree to within 3% /1 mm.
Energy Technology Data Exchange (ETDEWEB)
Davidson, Scott E., E-mail: sedavids@utmb.edu [Radiation Oncology, The University of Texas Medical Branch, Galveston, Texas 77555 (United States); Cui, Jing [Radiation Oncology, University of Southern California, Los Angeles, California 90033 (United States); Kry, Stephen; Ibbott, Geoffrey S.; Followill, David S. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Deasy, Joseph O. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Vicic, Milos [Department of Applied Physics, University of Belgrade, Belgrade 11000 (Serbia); White, R. Allen [Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)
2016-08-15
Purpose: A dose calculation tool, which combines the accuracy of the dose planning method (DPM) Monte Carlo code and the versatility of a practical analytical multisource model, which was previously reported has been improved and validated for the Varian 6 and 10 MV linear accelerators (linacs). The calculation tool can be used to calculate doses in advanced clinical application studies. One shortcoming of current clinical trials that report dose from patient plans is the lack of a standardized dose calculation methodology. Because commercial treatment planning systems (TPSs) have their own dose calculation algorithms and the clinical trial participant who uses these systems is responsible for commissioning the beam model, variation exists in the reported calculated dose distributions. Today’s modern linac is manufactured to tight specifications so that variability within a linac model is quite low. The expectation is that a single dose calculation tool for a specific linac model can be used to accurately recalculate dose from patient plans that have been submitted to the clinical trial community from any institution. The calculation tool would provide for a more meaningful outcome analysis. Methods: The analytical source model was described by a primary point source, a secondary extra-focal source, and a contaminant electron source. Off-axis energy softening and fluence effects were also included. The additions of hyperbolic functions have been incorporated into the model to correct for the changes in output and in electron contamination with field size. A multileaf collimator (MLC) model is included to facilitate phantom and patient dose calculations. An offset to the MLC leaf positions was used to correct for the rudimentary assumed primary point source. Results: Dose calculations of the depth dose and profiles for field sizes 4 × 4 to 40 × 40 cm agree with measurement within 2% of the maximum dose or 2 mm distance to agreement (DTA) for 95% of the data
Energy Technology Data Exchange (ETDEWEB)
Lambert, Dan P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Woodham, Wesley H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Williams, Matthew S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Newell, J. David [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Luther, Michelle C. [Auburn Univ., AL (United States); Brandenburg, Clayton H. [Univ.of South Carolina, Columbia, SC (United States)
2016-09-27
Testing was completed to develop a chemical processing flowsheet for the Defense Waste Processing Facility (DWPF), designed to vitrify and stabilize high level radioactive waste. DWPF processing uses a reducing acid (formic acid) and an oxidizing acid (nitric acid) to rheologically thin the slurry and complete the necessary acid base and reduction reactions (primarily mercury and manganese). Formic acid reduces mercuric oxide to elemental mercury, allowing the mercury to be removed during the boiling phase of processing through steam stripping. In runs with active catalysts, formic acid can decompose to hydrogen and nitrate can be reduced to ammonia, both flammable gases, due to rhodium and ruthenium catalysis. Replacement of formic acid with glycolic acid eliminates the generation of rhodium- and ruthenium-catalyzed hydrogen and ammonia. In addition, mercury reduction is still effective with glycolic acid. Hydrogen, ammonia and mercury are discussed in the body of the report. Ten abbreviated tests were completed to develop the operating window for implementation of the flowsheet and determine the impact of changes in acid stoichiometry and the blend of nitric and glycolic acid as it impacts various processing variables over a wide processing region. Three full-length 4-L lab-scale simulations demonstrated the viability of the flowsheet under planned operating conditions. The flowsheet is planned for implementation in early 2017.
International Nuclear Information System (INIS)
MacDonald, P.E.; Broughton, J.M.
1975-03-01
Fuel pellets crack extensively upon irradiation due both to thermal stresses induced by power changes and at high burnup, to accumulation of gaseous fission products at grain boundaries. Therefore, the distance between the fuel and cladding will be circumferentially nonuniform; varying between that calculated for intact operating fuel pellets and essentially zero (fuel segments in contact with the cladding wall). A model for calculation of temperatures in cracked pellets is proposed wherein the effective fuel to cladding gap conductance is calculated by taking a zero pressure contact conductance in series with an annular gap conductance. Comparisons of predicted and measured fuel centerline temperatures at beginning of life and at extended burnup are presented in support of the model. 13 references
Calculations of the energy spectra of Zn, Ga and Ge isotopes by the shell model
International Nuclear Information System (INIS)
Sakakura, M.; Shikata, Y.; Arima, A.; Sebe, T.
1979-01-01
The effective Hamiltonian which was determined empirically by Koops and Glaudemans is tested in shell model calculations for the 65-68 Zn, 67-69 Ga, and 68-70 Ge nuclei in the full (1p 3 / 2 , 0f 5 / 2 , 1p 1 / 2 )n space. The resulting energy spectra are compared with the experimental spectra and results of previous calculations. The overall agreement with experiment is as satisfactory for these nuclei as for the Ni and Cu isotopes, by which the Hamiltonian was determined. It is noticed that the spectra of 67 Zn and 67 , 69 Ga calculated in this work are similar to those provided by the Alaga model. (orig.) [de
International Nuclear Information System (INIS)
Honda, M.; Kajita, T.; Kasahara, K.; Midorikawa, S.
2011-01-01
We present the calculation of the atmospheric neutrino fluxes with an interaction model named JAM, which is used in PHITS (Particle and Heavy-Ion Transport code System) [K. Niita et al., Radiation Measurements 41, 1080 (2006).]. The JAM interaction model agrees with the HARP experiment [H. Collaboration, Astropart. Phys. 30, 124 (2008).] a little better than DPMJET-III[S. Roesler, R. Engel, and J. Ranft, arXiv:hep-ph/0012252.]. After some modifications, it reproduces the muon flux below 1 GeV/c at balloon altitudes better than the modified DPMJET-III, which we used for the calculation of atmospheric neutrino flux in previous works [T. Sanuki, M. Honda, T. Kajita, K. Kasahara, and S. Midorikawa, Phys. Rev. D 75, 043005 (2007).][M. Honda, T. Kajita, K. Kasahara, S. Midorikawa, and T. Sanuki, Phys. Rev. D 75, 043006 (2007).]. Some improvements in the calculation of atmospheric neutrino flux are also reported.
Spin-splitting calculation for zincblende semiconductors using an atomic bond-orbital model
International Nuclear Information System (INIS)
Kao, Hsiu-Fen; Lo, Ikai; Chiang, Jih-Chen; Wang, Wan-Tsang; Hsu, Yu-Chi; Wu, Chieh-Lung; Gau, Ming-Hong; Chen, Chun-Nan; Ren, Chung-Yuan; Lee, Meng-En
2012-01-01
We develop a 16-band atomic bond-orbital model (16ABOM) to compute the spin splitting induced by bulk inversion asymmetry in zincblende materials. This model is derived from the linear combination of atomic-orbital (LCAO) scheme such that the characteristics of the real atomic orbitals can be preserved to calculate the spin splitting. The Hamiltonian of 16ABOM is based on a similarity transformation performed on the nearest-neighbor LCAO Hamiltonian with a second-order Taylor expansion over k-vector at the Γ point. The spin-splitting energies in bulk zincblende semiconductors, GaAs and InSb, are calculated, and the results agree with the LCAO and first-principles calculations. However, we find that the spin-orbit coupling between bonding and antibonding p-like states, evaluated by the 16ABOM, dominates the spin splitting of the lowest conduction bands in the zincblende materials.
Model calculations of the influence of population distribution on the siting of nuclear power plants
International Nuclear Information System (INIS)
Nielsen, F.; Walmod-Larsen, O.
1984-02-01
This report was prepared for a working group established in April 1981 by the Danish Environmental Protection Agency with the task of investigating siting problems of nuclear power stations in Denmark. The purpose of the working group was to study the influence of the population density around a site on nuclear power safety. The importance of emergency planning should be studied as well. In this model study two specific accident sequences were simulated on a 1000 MWe nuclear power plant. The plant was assumed to be placed in the center of two different model population distributions. The concequences for the two population distributions from the two accidents were calculated for the most frequent weather conditions. Doses to individuals were calculated for the bone marrow, lungs, gastrointestinal tract, thyroidea and for the whole body. The collective whole body doses were also calculated for the two populations considered. (author)
Application of the annular dispersed flow model to two-phase critical flow calculation
International Nuclear Information System (INIS)
Ivandaev, A.I.; Nigmatulin, B.I.
1977-01-01
The application of the annular dispersed flow model with an effective monodisperse core to the calculation of vapour-liquid mixture maximum rates through long pipes is discussed. An effect of the main dominant parameters such as evaporation intensity, diameter of drops picked out from the film surface and initial drop diameter at the pipe inlet on the outlet critical condition formation process has been investigated. The corresponding model constants have been determined. The calculated and experimental values of critical rates and pressure profiles along the channel have been found to be in a satisfactory agreement in the studied range of parameters. The observed non-conformity of the calculated and experimental values of critical pressures and vapour contents can be due to inadequate accuracy of the experimental techniques
Calculational model for condensation of water vapor during an underground nuclear detonation
International Nuclear Information System (INIS)
Knox, R.J.
1975-01-01
An empirally derived mathematical model was developed to calculate the pressure and temperature history during condensation of water vapor in an underground-nuclear-explosion cavity. The condensation process is non-isothermal. Use has been made of the Clapeyron-Clausius equation as a basis for development of the model. Analytic fits to the vapor pressure and the latent heat of vaporization for saturated-water vapor, together with an estimated value for the heat-transfer coefficient, have been used to describe the phenomena. The calculated pressure-history during condensation has been determined to be exponential, with a time constant somewhat less than that observed during the cooling of the superheated steam from the explosion. The behavior of the calculated condensation-pressure compares well with the observed-pressure record (until just prior to cavity collapse) for a particular nuclear-detonation event for which data is available
International Nuclear Information System (INIS)
Waegeneers, Nadia; Ruttens, Ann; De Temmerman, Ludwig
2011-01-01
A chain model was developed to calculate the flow of cadmium from soil, drinking water and feed towards bovine tissues. The data used for model development were tissue Cd concentrations of 57 bovines and Cd concentrations in soil, feed and drinking water, sampled at the farms were the bovines were reared. Validation of the model occurred with a second set of measured tissue Cd concentrations of 93 bovines of which age and farm location were known. The exposure part of the chain model consists of two parts: (1) a soil-plant transfer model, deriving cadmium concentrations in feed from basic soil characteristics (pH and organic matter content) and soil Cd concentrations, and (2) bovine intake calculations, based on typical feed and water consumption patterns for cattle and Cd concentrations in feed and drinking water. The output of the exposure model is an animal-specific average daily Cd intake, which is then taken forward to a kinetic uptake model in which time-dependent Cd concentrations in bovine tissues are calculated. The chain model was able to account for 65%, 42% and 32% of the variation in observed kidney, liver and meat Cd concentrations in the validation study. - Research highlights: → Cadmium transfer from soil, drinking water and feed to bovine tissues was modeled. → The model was based on 57 bovines and corresponding feed and soil Cd concentrations. → The model was validated with an independent data set of 93 bovines. → The model explained 65% of variation in kidney Cd in the validation study.
Modelling lateral beam quality variations in pencil kernel based photon dose calculations
International Nuclear Information System (INIS)
Nyholm, T; Olofsson, J; Ahnesjoe, A; Karlsson, M
2006-01-01
Standard treatment machines for external radiotherapy are designed to yield flat dose distributions at a representative treatment depth. The common method to reach this goal is to use a flattening filter to decrease the fluence in the centre of the beam. A side effect of this filtering is that the average energy of the beam is generally lower at a distance from the central axis, a phenomenon commonly referred to as off-axis softening. The off-axis softening results in a relative change in beam quality that is almost independent of machine brand and model. Central axis dose calculations using pencil beam kernels show no drastic loss in accuracy when the off-axis beam quality variations are neglected. However, for dose calculated at off-axis positions the effect should be considered, otherwise errors of several per cent can be introduced. This work proposes a method to explicitly include the effect of off-axis softening in pencil kernel based photon dose calculations for arbitrary positions in a radiation field. Variations of pencil kernel values are modelled through a generic relation between half value layer (HVL) thickness and off-axis position for standard treatment machines. The pencil kernel integration for dose calculation is performed through sampling of energy fluence and beam quality in sectors of concentric circles around the calculation point. The method is fully based on generic data and therefore does not require any specific measurements for characterization of the off-axis softening effect, provided that the machine performance is in agreement with the assumed HVL variations. The model is verified versus profile measurements at different depths and through a model self-consistency check, using the dose calculation model to estimate HVL values at off-axis positions. A comparison between calculated and measured profiles at different depths showed a maximum relative error of 4% without explicit modelling of off-axis softening. The maximum relative error
Comparison of Steady-State SVC Models in Load Flow Calculations
DEFF Research Database (Denmark)
Chen, Peiyuan; Chen, Zhe; Bak-Jensen, Birgitte
2008-01-01
This paper compares in a load flow calculation three existing steady-state models of static var compensator (SVC), i.e. the generator-fixed susceptance model, the total susceptance model and the firing angle model. The comparison is made in terms of the voltage at the SVC regulated bus, equivalent...... SVC susceptance at the fundamental frequency and the load flow convergence rate both when SVC is operating within and on the limits. The latter two models give inaccurate results of the equivalent SVC susceptance as compared to the generator model due to the assumption of constant voltage when the SVC...... is operating within the limits. This may underestimate or overestimate the SVC regulating capability. Two modified models are proposed to improve the SVC regulated voltage according to its steady-state characteristic. The simulation results of the two modified models show the improved accuracy...
Use of realistic anthropomorphic models for calculation of radiation dose in nuclear medicine
International Nuclear Information System (INIS)
Stabin, Michael G.; Emmons, Mary A.; Fernald, Michael J.; Brill, A.B.; Segars, W.Paul
2008-01-01
Anthropomorphic phantoms based on simple geometric structures have been used in radiation dose calculations for many years. We have now developed a series of anatomically realistic phantoms representing adults and children using body models based on non-uniform rational B-spline (NURBS), with organ and body masses based on the reference values given in ICRP Publication 89. Age-dependent models were scaled and shaped to represent the reference individuals described in ICRP 89 (male and female adults, newborns, 1-, 5-, 10- and 15-year-olds), using a software tool developed in Visual C++. Voxel-based versions of these models were used with GEANT4 radiation transport codes for calculation of specific absorbed fractions (SAFs) for internal sources of photons and electrons, using standard starting energy values. Organ masses in the models were within a few % of ICRP reference masses, and physicians reviewed the models for anatomical realism. Development of individual phantoms was much faster than manual segmentation of medical images, and resulted in a very uniform standardized phantom series. SAFs were calculated on the Vanderbilt multi node computing network (ACCRE). Photon and electron SAFs were calculated for all organs in all models, and were compared to values from similar phantoms developed by others. Agreement was very good in most cases; some differences were seen, due to differences in organ mass and geometry. This realistic phantom series represents a possible replacement for the Cristy/Eckerman series of the 1980's. Both phantom sets will be included in the next release of the OLINDA/EXM personal computer code, and the new phantoms will be made generally available to the research community for other uses. Calculated radiation doses for diagnostic and therapeutic radiopharmaceuticals will be compared with previous values. (author)
International Nuclear Information System (INIS)
Artemov, V.G.; Gusev, V.I.; Zinatullin, R.E.; Karpov, A.S.
2007-01-01
Using modeled WWER cram rod drop experiments, performed at the Rostov NPP, as an example, the influence of delayed neutron parameters on the modeling results was investigated. The delayed neutron parameter values were taken from both domestic and foreign nuclear databases. Numerical modeling was carried out on the basis of SAPFIR 9 5andWWERrogram package. Parameters of delayed neutrons were acquired from ENDF/B-VI and BNAB-78 validated data files. It was demonstrated that using delay fraction data from different databases in reactivity meters led to significantly different reactivity results. Based on the results of numerically modeled experiments, delayed neutron parameters providing the best agreement between calculated and measured data were selected and recommended for use in reactor calculations (Authors)
Energy Technology Data Exchange (ETDEWEB)
Solvang Jensen, S.; Loefstroem, P.; Berkowich, R.; Roerdam Olsen, H.; Frydendall, J. [DMU, Afd. for Atmosfaerisk Miljoe, Roskilde (DK); Fuglsang, K. [FORCE Technology, Broendby (Denmark); Hummelshoej, P. [MetSupport, Roskilde (Denmark)
2004-12-01
This report describes the air quality along Koege Bugt motorway, one of the most trafficked sections in Denmark. A number of measurements have been carried out along Koege Bugt motorway at Greve for a three-month period in the autumn of 2003. For the first time in Denmark, NO{sub x} were measured with high time dissolution from different distances of the motorway. Furthermore, a number of meteorological parameters were measured in order to map local meteorological conditions. An air quality model describing dispersal and conversion has been made on the basis of the OML model. The OML model is modified in order to take traffic-made turbulence into consideration. The model has been evaluated through comparisons between measurements and simulated calculations. Furthermore, simulated calculations for the year 2003 has been made for comparison with extreme values. (BA)
Calculation model for 16N transit time in the secondary side of steam generators
International Nuclear Information System (INIS)
Liu Songyu; Xu Jijun; Xu Ming
1998-01-01
The 16 N transit time is essential to determine the leak-rate of steam generator tubes leaks with 16 N monitoring system, which is a new technique. A model was developed for calculation 16 N transit time in the secondary side of steam generators. According to the flow characters of secondary side fluid, the transit times divide into four sectors from tube sheet to the sensor on steam line. The model assumes that 16 N is moving as vapor phase in the secondary-side. So the model for vapor velocity distribution in tube bundle is presented in detail. The 16 N transit time calculation results of this model compare with these of EDF on steam generator of Qinshan NPP
Calculations of Inflaton Decays and Reheating: with Applications to No-Scale Inflation Models
Ellis, John; Nanopoulos, Dimitri V; Olive, Keith A
2015-01-01
We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\\rm reh}$, and the number of inflationary e-folds, $N_*$, comparing analytical approximations with numerical calculations. We then illustrate these results with applications to models based on no-scale supergravity and motivated by generic string compactifications, including scenarios where the inflaton is identified as an untwisted-sector matter field with direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions. Finally, we use our results to discuss the constraints on these models imposed by present measurements of the scalar spectral index $n_s$ and the tensor-to-scalar perturbation ratio $r$, converting them into constraints on $N_*$, the inflaton decay rate and other parameters of specific no-scale inflationary models.
International Nuclear Information System (INIS)
Pamela, J.
1990-10-01
Negative ion extraction is described by a model which includes electron diffusion across transverse magnetic fields in the sheath. This model allows a 2-Dimensional approximation of the problem. It is used to introduce electron space charge effects in a 2-D particle trajectory code, designed for negative ion optics calculations. Another physical effect, the stripping of negative ions on neutral gas atoms, has also been included in our model; it is found to play an important role in negative ion optics. The comparison with three sets of experimental data from very different negative ion accelerators, show that our model is able of accurate predictions
A new simulation model for calculating the internal exposure of some radionuclides
Directory of Open Access Journals (Sweden)
Mahrous Ayman
2009-01-01
Full Text Available A new model based on a series of mathematical functions for estimating excretion rates following the intake of nine different radionuclides is presented in this work. The radionuclides under investigation are: cobalt, iodine, cesium, strontium, ruthenium, radium, thorium, plutonium, and uranium. The committed effective dose has been calculated by our model so as to obtain the urinary and faecal excretion rates for each radionuclide. The said model is further validated by a comparison with the widely spread Mondal software and a simulation program. The results obtained show a harmony between the Mondal package and the model we have constructed.
Direct Monte Carlo dose calculation using polygon-surface computational human model
International Nuclear Information System (INIS)
Jeong, Jong Hwi; Kim, Chan Hyeong; Yeom, Yeon Su; Cho, Sungkoo; Chung, Min Suk; Cho, Kun-Woo
2011-01-01
In the present study, a voxel-type computational human model was converted to a polygon-surface model, after which it was imported directly to the Geant4 code without using a voxelization process, that is, without converting back to a voxel model. The original voxel model was also imported to the Geant4 code, in order to compare the calculated dose values and the computational speed. The average polygon size of the polygon-surface model was ∼0.5 cm 2 , whereas the voxel resolution of the voxel model was 1.981 × 1.981 × 2.0854 mm 3 . The results showed a good agreement between the calculated dose values of the two models. The polygon-surface model was, however, slower than the voxel model by a factor of 6–9 for the photon energies and irradiation geometries considered in the present study, which nonetheless is considered acceptable, considering that direct use of the polygon-surface model does not require a separate voxelization process. (author)
One kind of atmosphere-ocean three layer model for calculating the velocity of ocean current
Energy Technology Data Exchange (ETDEWEB)
Jing, Z; Xi, P
1979-10-01
A three-layer atmosphere-ocean model is given in this paper to calcuate the velocity of ocean current, particularly the function of the vertical coordinate, taking into consideratiln (1) the atmospheric effect on the generation of ocean current, (2) a calculated coefficient of the eddy viscosity instead of an assumed one, and (3) the sea which actually varies in depth.
Ab initio calculation of the sound velocity of dense hydrogen: implications for models of Jupiter
Alavi, A.; Parrinello, M.; Frenkel, D.
1995-01-01
First-principles molecular dynamics simulations were used to calculate the sound velocity of dense hydrogen, and the results were compared with extrapolations of experimental data that currently conflict with either astrophysical models or data obtained from recent global oscillation measurements of
A new timing model for calculating the intrinsic timing resolution of a scintillator detector
International Nuclear Information System (INIS)
Shao Yiping
2007-01-01
The coincidence timing resolution is a critical parameter which to a large extent determines the system performance of positron emission tomography (PET). This is particularly true for time-of-flight (TOF) PET that requires an excellent coincidence timing resolution (<<1 ns) in order to significantly improve the image quality. The intrinsic timing resolution is conventionally calculated with a single-exponential timing model that includes two parameters of a scintillator detector: scintillation decay time and total photoelectron yield from the photon-electron conversion. However, this calculation has led to significant errors when the coincidence timing resolution reaches 1 ns or less. In this paper, a bi-exponential timing model is derived and evaluated. The new timing model includes an additional parameter of a scintillator detector: scintillation rise time. The effect of rise time on the timing resolution has been investigated analytically, and the results reveal that the rise time can significantly change the timing resolution of fast scintillators that have short decay time constants. Compared with measured data, the calculations have shown that the new timing model significantly improves the accuracy in the calculation of timing resolutions
The one loop calculation of the strong coupling β function in the Toy Model
International Nuclear Information System (INIS)
Bai Zhiming; Jiang Yuanfang
1991-01-01
The background field quantization is used to calculate the one-loop β function in the Toy Model which has the strong coupling and the SU(3) symmetry. The function obtained is consistent with the Appalquist-Carrazone theorem in the low energy condition
Raman Spectroscopy and Ab-Initio Model Calculations on Ionic Liquids
DEFF Research Database (Denmark)
Berg, Rolf W.
2007-01-01
spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT-Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methylimidazolium ([C4mim][X]) salts. The rotational isomerism of the [C4mim]þ cation is described: the presence of anti...
Calculation of spherical models of lead with a source of 14 MeV-neutrons
International Nuclear Information System (INIS)
Markovskij, D.V.; Borisov, A.A.
1989-01-01
Neutron transport calculations for spherical models of lead have been done with the one-dimensional code BLANK realizing the direct Monte Carlo method in the whole range of neutron energies and they are compared with the experimental results. 6 refs, 10 figs, 3 tabs
Covariance matrices for nuclear cross sections derived from nuclear model calculations
International Nuclear Information System (INIS)
Smith, D. L.
2005-01-01
The growing need for covariance information to accompany the evaluated cross section data libraries utilized in contemporary nuclear applications is spurring the development of new methods to provide this information. Many of the current general purpose libraries of evaluated nuclear data used in applications are derived either almost entirely from nuclear model calculations or from nuclear model calculations benchmarked by available experimental data. Consequently, a consistent method for generating covariance information under these circumstances is required. This report discusses a new approach to producing covariance matrices for cross sections calculated using nuclear models. The present method involves establishing uncertainty information for the underlying parameters of nuclear models used in the calculations and then propagating these uncertainties through to the derived cross sections and related nuclear quantities by means of a Monte Carlo technique rather than the more conventional matrix error propagation approach used in some alternative methods. The formalism to be used in such analyses is discussed in this report along with various issues and caveats that need to be considered in order to proceed with a practical implementation of the methodology
Shell-model calculations with a basis that contains correlated pairs
International Nuclear Information System (INIS)
Boisson, J.P.; Silvestre-Brac, B.A.; Liotta, R.J.
1979-01-01
A method to solve the shell-model equations within a basis that contains correlated pairs of particles is presented. The method is illustrated for the three-identical-particle system. Applications in nuclei around 208 Pb are given and comparisons with both experimental data and other calculations are carried out. (Auth.)
Black Hole Entropy Calculation in a Modified Thin Film Model Jingyi ...
Indian Academy of Sciences (India)
Abstract. The thin film model is modified to calculate the black hole entropy. The difference from the original method is that the Parikh–. Wilczek tunnelling framework is introduced and the self-gravitation of the emission particles is taken into account. In terms of our improvement, if the entropy is still proportional to the area, ...
Model-Independent Calculation of Radiative Neutron Capture on Lithium-7
Rupak, Gautam; Higa, Renato
2011-01-01
The radiative neutron capture on lithium-7 is calculated model independently using a low-energy halo effective field theory. The cross section is expressed in terms of scattering parameters directly related to the S-matrix elements. It depends on the poorly known p-wave effective range parameter
Large scale shell model calculations: the physics in and the physics out
International Nuclear Information System (INIS)
Zuker, A.P.
1997-01-01
After giving a few examples of recent results of the (SM) 2 collaboration, the monopole modified realistic interactions to be used in shell model calculations are described and analyzed. Rotational motion is discussed in some detail, and some introductory remarks on level densities are made. (orig.)
Seldam, C.A. ten; Groot, S.R. de
1952-01-01
From Jensen's and Gombás' modification of the statistical Thomas-Fermi atom model, a theory for compressed atoms is developed by changing the boundary conditions. Internal kinetic energy and polarizability of argon are calculated as functions of pressure. At 1000 atm. an internal kinetic energy of
Progress in the improved lattice calculation of direct CP-violation in the Standard Model
Kelly, Christopher
2018-03-01
We discuss the ongoing effort by the RBC & UKQCD collaborations to improve our lattice calculation of the measure of Standard Model direct CP violation, ɛ', with physical kinematics. We present our progress in decreasing the (dominant) statistical error and discuss other related activities aimed at reducing the systematic errors.
Abramopoulos, F.; Rosenzweig, C.; Choudhury, B.
1988-09-01
A physically based ground hydrology model is developed to improve the land-surface sensible and latent heat calculations in global climate models (GCMs). The processes of transpiration, evaporation from intercepted precipitation and dew, evaporation from bare soil, infiltration, soil water flow, and runoff are explicitly included in the model. The amount of detail in the hydrologic calculations is restricted to a level appropriate for use in a GCM, but each of the aforementioned processes is modeled on the basis of the underlying physical principles. Data from the Goddard Institute for Space Studies (GISS) GCM are used as inputs for off-line tests of the ground hydrology model in four 8° × 10° regions (Brazil, Sahel, Sahara, and India). Soil and vegetation input parameters are calculated as area-weighted means over the 8° × 10° gridhox. This compositing procedure is tested by comparing resulting hydrological quantities to ground hydrology model calculations performed on the 1° × 1° cells which comprise the 8° × 10° gridbox. Results show that the compositing procedure works well except in the Sahel where lower soil water levels and a heterogeneous land surface produce more variability in hydrological quantities, indicating that a resolution better than 8° × 10° is needed for that region. Modeled annual and diurnal hydrological cycles compare well with observations for Brazil, where real world data are available. The sensitivity of the ground hydrology model to several of its input parameters was tested; it was found to be most sensitive to the fraction of land covered by vegetation and least sensitive to the soil hydraulic conductivity and matric potential.
A three-dimensional model for calculating the micro disk laser resonant-modes
International Nuclear Information System (INIS)
Sabetjoo, H.; Bahrampor, A.; Farrahi-Moghaddam, R.
2006-01-01
In this article, a semi-analytical model for theoretical analysis of micro disk lasers is presented. Using this model, the necessary conditions for the existence of loss less and low-loss modes of micro-resonators are obtained. The resonance frequency of the resonant modes and also the attenuation of low-loss modes are calculated. By comparing the results with results of finite difference method, their validity is certified.
Beriro, D. J.; Abrahart, R. J.; Nathanail, C. P.
2012-04-01
Data-driven modelling is most commonly used to develop predictive models that will simulate natural processes. This paper, in contrast, uses Gene Expression Programming (GEP) to construct two alternative models of different pan evaporation estimations by means of symbolic regression: a simulator, a model of a real-world process developed on observed records, and an emulator, an imitator of some other model developed on predicted outputs calculated by that source model. The solutions are compared and contrasted for the purposes of determining whether any substantial differences exist between either option. This analysis will address recent arguments over the impact of using downloaded hydrological modelling datasets originating from different initial sources i.e. observed or calculated. These differences can be easily be overlooked by modellers, resulting in a model of a model developed on estimations derived from deterministic empirical equations and producing exceptionally high goodness-of-fit. This paper uses different lines-of-evidence to evaluate model output and in so doing paves the way for a new protocol in machine learning applications. Transparent modelling tools such as symbolic regression offer huge potential for explaining stochastic processes, however, the basic tenets of data quality and recourse to first principles with regard to problem understanding should not be trivialised. GEP is found to be an effective tool for the prediction of observed and calculated pan evaporation, with results supported by an understanding of the records, and of the natural processes concerned, evaluated using one-at-a-time response function sensitivity analysis. The results show that both architectures and response functions are very similar, implying that previously observed differences in goodness-of-fit can be explained by whether models are applied to observed or calculated data.
A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions
International Nuclear Information System (INIS)
Watson, E.E.; Stabin, M.G.
1987-01-01
Existing models which allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs.; 2 figs
A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions
International Nuclear Information System (INIS)
Watson, E.E.; Stabin, M.G.
1986-01-01
Existing models that allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six, and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs., 2 figs
Directory of Open Access Journals (Sweden)
Ernesto Amato
2014-03-01
Full Text Available We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'generalized radius', calculated as 3V/S, where V is the ellipsoid volume and S its surface. Radiation-specific parametric functions were obtained in order to calculate the absorbed fraction of a given radiation in a generic ellipsoidal volume. The dose from a generic radionuclide can be calculated through a process of summation and integration over the whole radionuclide emission spectrum, profitably implemented in an electronic spreadsheet. We compared the results of our analytical calculation approach with those obtained from the OLINDA/EXM computer software, finding a good agreement in a wide range of sphere radii, for the high-energy pure beta emitter 90Y, the commonly employed beta-gamma emitter 131I, and the pure alpha emitter 213Po. The generality of our approach makes it useful an easy to implement in clinical dosimetry calculations as well as in radiation safety estimations when doses from internal radionuclide uptake are to be taken into account.
NFAP calculation of the response of a 1/6 scale reinforced concrete containment model
International Nuclear Information System (INIS)
Costantino, C.J.; Pepper, S.; Reich, M.
1989-01-01
The details associated with the NFAP calculation of the pressure response of the 1/6th scale model containment structure are discussed in this paper. Comparisons are presented of some of the primary items of interest with those determined from the experiment. It was found from this comparison that the hoop response of the containment wall was adequately predicted by the NFAP finite element calculation, including the response in the high pressure, high strain range at which cracking of the concrete and yielding of the hoop reinforcement occurred. In the vertical or meridional direction, it was found that the model was significantly softer than predicted by the finite element calculation; that is, the vertical strains in the test were three to four times larger than computed in the NFAP calculation. These differences were noted even at low strain levels at which the concrete would not be expected to be cracked under tensile loadings. Simplified calculations for the containment indicate that the vertical stiffness of the wall is similar to that which would be determined by assuming the concrete fully cracked. Thus, the experiment indicates an anomalous behavior in the vertical direction
NFAP calculation of pressure response of 1/6th scale model containment structure
International Nuclear Information System (INIS)
Costantino, C.J.; Pepper, S.; Reich, M.
1988-01-01
The details associated with the NFAP calculation of the pressure response of the 1/6th scale model containment structure are discussed in this paper. Comparisons are presented of some of the primary items of interest with those determined from the experiment. It was found from this comparison that the hoop response of the containment wall was adequately predicted by the NFAP finite element calculation, including the response in the high pressure, high strain range at which cracking of the concrete and yielding of the hoop reinforcement occurred. In the vertical or meridional direction, it was found that the model was significantly softer than predicted by the finite element calculation; that is, the vertical strains in the test were three to four times larger than computed in the NFAP calculation. These differences were noted even at low strain levels at which the concrete would not be expected to be cracked under tensile loadings. Simplified calculations for the containment indicate that the vertical stiffness of the wall is similar to that which would be determined by assuming the concrete fully cracked. Thus, the experiment indicates an anomalous behavior in the vertical direction
Merker, L.; Costi, T. A.
2012-08-01
We introduce a method to obtain the specific heat of quantum impurity models via a direct calculation of the impurity internal energy requiring only the evaluation of local quantities within a single numerical renormalization group (NRG) calculation for the total system. For the Anderson impurity model we show that the impurity internal energy can be expressed as a sum of purely local static correlation functions and a term that involves also the impurity Green function. The temperature dependence of the latter can be neglected in many cases, thereby allowing the impurity specific heat Cimp to be calculated accurately from local static correlation functions; specifically via Cimp=(∂Eionic)/(∂T)+(1)/(2)(∂Ehyb)/(∂T), where Eionic and Ehyb are the energies of the (embedded) impurity and the hybridization energy, respectively. The term involving the Green function can also be evaluated in cases where its temperature dependence is non-negligible, adding an extra term to Cimp. For the nondegenerate Anderson impurity model, we show by comparison with exact Bethe ansatz calculations that the results recover accurately both the Kondo induced peak in the specific heat at low temperatures as well as the high-temperature peak due to the resonant level. The approach applies to multiorbital and multichannel Anderson impurity models with arbitrary local Coulomb interactions. An application to the Ohmic two-state system and the anisotropic Kondo model is also given, with comparisons to Bethe ansatz calculations. The approach could also be of interest within other impurity solvers, for example, within quantum Monte Carlo techniques.
Energy Technology Data Exchange (ETDEWEB)
Martino, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-08-08
An evaluation of the previous Chemical Processing Cell (CPC) testing was performed to determine whether the planned concurrent operation, or “coupled” operations, of the Defense Waste Processing Facility (DWPF) with the Salt Waste Processing Facility (SWPF) has been adequately covered. Tests with the nitricglycolic acid flowsheet, which were both coupled and uncoupled with salt waste streams, included several tests that required extended boiling times. This report provides the evaluation of previous testing and the testing recommendation requested by Savannah River Remediation. The focus of the evaluation was impact on flammability in CPC vessels (i.e., hydrogen generation rate, SWPF solvent components, antifoam degradation products) and processing impacts (i.e., acid window, melter feed target, rheological properties, antifoam requirements, and chemical composition).
Recent developments in biokinetic models and the calculation of internal dose coefficients
International Nuclear Information System (INIS)
Fell, T.P.; Phipps, A.W.; Kendall, G.M.; Stradling, G.N.
1997-01-01
In most cases the measurement of radioactivity in an environmental or biological sample will be followed by some estimation of dose and possibly risk, either to a population or an individual. This will normally involve the use of a dose coefficient (dose per unit intake value) taken from a compendium. In recent years the calculation of dose coefficients has seen many developments in both biokinetic modelling and computational capabilities. ICRP has recommended new models for the respiratory tract and for the systemic behavior of many of the more important elements. As well as this, a general age-dependent calculation method has been developed which involves an effectively continuous variation of both biokinetic and dosimetric parameters, facilitating more realistic estimation of doses to young people. These new developments were used in work for recent ICRP, IAEA and CEC compendia of dose coefficients for both members of the public (including children) and workers. This paper presents a general overview of the method of calculation of internal doses with particular reference to the actinides. Some of the implications for dose coefficients of the new models are discussed. For example it is shown that compared with data in ICRP Publications 30 and 54: the new respiratory tract model generally predicts lower deposition in systemic tissues per unit intake; the new biokinetic models for actinides allow for burial of material deposited on bone surfaces; age-dependent models generally feature faster turnover of material in young people. All of these factors can lead to substantially different estimates of dose and examples of the new dose coefficients are given to illustrate these differences. During the development of the new models for actinides, human bioassay data were used to validate the model. Thus, one would expect the new models to give reasonable predictions of bioassay quantities. Some examples of the bioassay applications, e.g., excretion data for the
Sarkadi, L.
2018-04-01
Fully differential cross sections (FDCSs) have been calculated for the single ionization of helium by 1- and 3-MeV proton and 100-MeV/u C6 + ion impact using the classical trajectory Monte Carlo (CTMC) method in the nonrelativistic, three-body approximation. The calculations were made employing a Wigner-type model in which the quantum-mechanical position distribution of the electron is approximated by a weighted integral of the microcanonical distribution over a range of the binding energy of the electron. In the scattering plane, the model satisfactorily reproduces the observed shape of the binary peak. In the region of the peak the calculated FDCSs agree well with the results of continuum-distorted-wave calculations for all the investigated collisions. For 1-MeV proton impact the experimentally observed shift of the binary peak with respect to the first Born approximation is compared with the shifts obtained by different higher-order quantum-mechanical theories and the present CTMC method. The best result was achieved by CTMC, but still a large part of the shift remained unexplained. Furthermore, it was found that the classical theory failed to reproduce the shape of the recoil peak observed in the experiments, it predicts a much narrower peak. This indicates that the formation of the recoil peak is dominated by quantum-mechanical effects. For 100-MeV/u C6 + ion impact the present CTMC calculations confirmed the existence of the "double-peak" structure of the angular distribution of the electron in the plane perpendicular to the momentum transfer, in accordance with the observation, the prediction of an incoherent semiclassical model, and previous CTMC results. This finding together with wave-packet calculations suggests that the "C6 + puzzle" may be solved by considering the loss of the projectile coherence. Experiments to be conducted using ion beams of anisotropic coherence are proposed for a more differential investigation of the ionization dynamics.
Generic model for calculating carbon footprint of milk using four different LCA modelling approaches
DEFF Research Database (Denmark)
Dalgaard, Randi; Schmidt, Jannick Højrup; Flysjö, Anna
2014-01-01
The aim of the study is to develop a tool, which can be used for calculation of carbon footprint (using a life cycle assessment (LCA) approach) of milk both at a farm level and at a national level. The functional unit is ‘1 kg energy corrected milk (ECM) at farm gate’ and the applied methodology...
On the stress calculation within phase-field approaches: a model for finite deformations
Schneider, Daniel; Schwab, Felix; Schoof, Ephraim; Reiter, Andreas; Herrmann, Christoph; Selzer, Michael; Böhlke, Thomas; Nestler, Britta
2017-08-01
Numerical simulations based on phase-field methods are indispensable in order to investigate interesting and important phenomena in the evolution of microstructures. Microscopic phase transitions are highly affected by mechanical driving forces and therefore the accurate calculation of the stresses in the transition region is essential. We present a method for stress calculations within the phase-field framework, which satisfies the mechanical jump conditions corresponding to sharp interfaces, although the sharp interface is represented as a volumetric region using the phase-field approach. This model is formulated for finite deformations, is independent of constitutive laws, and allows using any type of phase inherent inelastic strains.
Effect of film roughness in Fe/MgO/Fe magnetic tunnel junctions: model calculations
Energy Technology Data Exchange (ETDEWEB)
Edalati Boostan, Saeideh; Heiliger, Christian [I. Physikalisches Institut, Justus Liebig University Giessen, D-35392 (Germany); Moradi, Hosein [Department of Physics,Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)
2011-07-01
We calculate how interface roughness affects the tunneling magnetoresistance (TMR) in Fe/MgO/Fe (100) junctions. The used method is based on a single-band tight-binding (SBTB) approximation employing the Green's function formalism. We investigate the influence of disorder at the TMR ratio. Thereby, the disorder is modeled by considering different occupation probabilities of Fe and MgO at interface sites. We calculate the current densities for parallel and anti-parallel configurations for different disorders. The results show that the roughness decreases the TMR that match well with experimental observations.
International Nuclear Information System (INIS)
Strenge, D.L.; Watson, E.C.; Droppo, J.G.
1976-06-01
The development of technological bases for siting nuclear fuel cycle facilities requires calculational models and computer codes for the evaluation of risks and the assessment of environmental impact of radioactive effluents. A literature search and review of available computer programs revealed that no one program was capable of performing all of the great variety of calculations (i.e., external dose, internal dose, population dose, chronic release, accidental release, etc.). Available literature on existing computer programs has been reviewed and a description of each program reviewed is given
Energy Technology Data Exchange (ETDEWEB)
Strenge, D.L.; Watson, E.C.; Droppo, J.G.
1976-06-01
The development of technological bases for siting nuclear fuel cycle facilities requires calculational models and computer codes for the evaluation of risks and the assessment of environmental impact of radioactive effluents. A literature search and review of available computer programs revealed that no one program was capable of performing all of the great variety of calculations (i.e., external dose, internal dose, population dose, chronic release, accidental release, etc.). Available literature on existing computer programs has been reviewed and a description of each program reviewed is given.
International Nuclear Information System (INIS)
Androsenko, A.A.; Androsenko, P.A.; Deeva, V.V.; Prokof'eva, Z.A.
1990-01-01
Analysis is made for the effect of mathematical model accuracy of the system concerned on the calculation results using the BRAND program system. Consideration is given to the impact of the following factors: accuracy of neutron source energy-angular characteristics description, various degrees of system geometry approximation, adequacy of Monte-Carlo method estimation to a real physical neutron detector. The calculation results analysis is made on the basis of the experiments on leakage neutron spectra measurement in spherical lead assemblies with the 14 MeV-neutron source in the centre. 4 refs.; 2 figs.; 10 tabs
Bimodality emerges from transport model calculations of heavy ion collisions at intermediate energy
Mallik, S.; Das Gupta, S.; Chaudhuri, G.
2016-04-01
This work is a continuation of our effort [S. Mallik, S. Das Gupta, and G. Chaudhuri, Phys. Rev. C 91, 034616 (2015)], 10.1103/PhysRevC.91.034616 to examine if signatures of a phase transition can be extracted from transport model calculations of heavy ion collisions at intermediate energy. A signature of first-order phase transition is the appearance of a bimodal distribution in Pm(k ) in finite systems. Here Pm(k ) is the probability that the maximum of the multiplicity distribution occurs at mass number k . Using a well-known model for event generation [Botzmann-Uehling-Uhlenbeck (BUU) plus fluctuation], we study two cases of central collision: mass 40 on mass 40 and mass 120 on mass 120. Bimodality is seen in both the cases. The results are quite similar to those obtained in statistical model calculations. An intriguing feature is seen. We observe that at the energy where bimodality occurs, other phase-transition-like signatures appear. There are breaks in certain first-order derivatives. We then examine if such breaks appear in standard BUU calculations without fluctuations. They do. The implication is interesting. If first-order phase transition occurs, it may be possible to recognize that from ordinary BUU calculations. Probably the reason this has not been seen already is because this aspect was not investigated before.
Directory of Open Access Journals (Sweden)
Tomasz Topoliński
2012-01-01
Full Text Available Trabecular bone cores were collected from the femoral head at the time of surgery (hip arthroplasty. Investigated were 42 specimens, from patients with osteoporosis and coxarthrosis. The cores were scanned used computer microtomography (microCT system at an isotropic spatial resolution of 36 microns. Image stacks were converted to finite element models via a bone voxel-to-element algorithm. The apparent modulus was calculated based on the assumptions that for the elastic properties, E=10 MPa and ν=0.3. The compressive deformation as calculated by finite elements (FE analysis was 0.8%. The models were coarsened to effectively change the resolution or voxel size (from 72 microns to 288 microns or from 72 microns to 1080 microns. The aim of our study is to determine how an increase in the distance between scans changes the elastic properties as calculated by FE models. We tried to find a border value voxel size at which the module values were possible to calculate. As the voxel size increased, the mean voxel volume increased and the FEA-derived apparent modulus decreased. The slope of voxel size versus modulus relationship correlated with several architectural indices of trabecular bone.
A model for the calculation of the radiation dose from natural radionuclides in The Netherlands
International Nuclear Information System (INIS)
Ackers, J.G.
1986-02-01
A model has been developed to calculate the radiation dose incurred from natural radioactivity indoors and outdoors, expressed in effective dose equivalence/year. The model is applied on a three rooms dwelling characterized by interconnecting air flows and on a dwelling with crawlspace. In this model the distinct parameters are variable in order to allow the investigation of the relative influence. The calculated effective dose equivalent for an adult in the dwelling was calculated to be about 1.7 mSv/year, composed of 15% from cosmic radiation, 35% from terrestrial radioactivity, 20% from radioactivity in the body and 30% from natural radionuclides in building materials. The calculations show an enhancement of about a factor of two in radon concentration in air in a room which is ventilated by air from an adjacent room. It is also shown that the attachment rate of radon products to aerosols and the plate-out effect are relatively important parameters influencing the magnitude of the dose rate. (Auth.)
Calculation method of passive tracer using regional ocean modeling system (ROMS)
International Nuclear Information System (INIS)
Tubono, Takaki; Tsumune, Daisuke; Misumi, Kazuhiro; Yoshida, Yoshikatsu
2010-01-01
A dose assessments method for packages shipping radioactive materials was developed to calculate concentrations of radioactive materials discharged from the hypothetically sinking point using Regional Ocean Modeling System (ROMS). The programs of ROMS were improved for simultaneously calculating the flow fields around Japan and the concentrations discharged from several bottom points in the continental shelf. The model domain covered the northeast pacific region around Japan, 20degN-65degN, 120degE-165degE, with 1/10 degree horizontal resolution and 30 sigma-levels. The ROMS model captured main features such as Kuroshio currents, including the separation location and the Kuroshio extension, and Oyashio currents. The calculated volume transports through the main straits such as Tokara strait, Tsushima strait and Tsugaru strait were compared well to the measured or estimated that. The calculated concentrations discharged from 12 bottom points showed mixing associated with the eddies of ocean currents. This method is available to evaluate effectively the concentrations of radioactive materials only by setting the subsidence location and the concentrations and volume discharged. (author)
A new model for the accurate calculation of natural gas viscosity
Directory of Open Access Journals (Sweden)
Xiaohong Yang
2017-03-01
Full Text Available Viscosity of natural gas is a basic and important parameter, of theoretical and practical significance in the domain of natural gas recovery, transmission and processing. In order to obtain the accurate viscosity data efficiently at a low cost, a new model and its corresponding functional relation are derived on the basis of the relationship among viscosity, temperature and density derived from the kinetic theory of gases. After the model parameters were optimized using a lot of experimental data, the diagram showing the variation of viscosity along with temperature and density is prepared, showing that: ① the gas viscosity increases with the increase of density as well as the increase of temperature in the low density region; ② the gas viscosity increases with the decrease of temperature in high density region. With this new model, the viscosity of 9 natural gas samples was calculated precisely. The average relative deviation between these calculated values and 1539 experimental data measured at 250–450 K and 0.10–140.0 MPa is less than 1.9%. Compared with the 793 experimental data with a measurement error less than 0.5%, the maximum relative deviation is less than 0.98%. It is concluded that this new model is more advantageous than the previous 8 models in terms of simplicity, accuracy, fast calculation, and direct applicability to the CO2 bearing gas samples.
Experience at Los Alamos with use of the optical model for applied nuclear data calculations
International Nuclear Information System (INIS)
Young, P.G.
1994-01-01
While many nuclear models are important in calculations of nuclear data, the optical model usually provides the basic underpinning of analyses directed at data for applications. An overview is given here of experience in the Nuclear Theory and Applications Group at Los Alamos National Laboratory in the use of the optical model for calculations of nuclear cross section data for applied purposes. We consider the direct utilization of total, elastic, and reaction cross sections for neutrons, protons, deuterons, tritons, 3 He and alpha particles in files of evaluated nuclear data covering the energy range of 0 to 200 MeV, as well as transmission coefficients for reaction theory calculations and neutron and proton wave functions direct-reaction and Feshbach-Kerman-Koonin analyses. Optical model codes such as SCAT and ECIS and the reaction theory codes COMNUC, GNASH FKK-GNASH, and DWUCK have primarily been used in our analyses. A summary of optical model parameterizations from past analyses at Los Alamos will be given, including detailed tabulations of the parameters for a selection of nuclei
Experience at Los Alamos with use of the optical model for applied nuclear data calculations
International Nuclear Information System (INIS)
Young, P.G.
1998-01-01
While many nuclear models are important in calculations of nuclear data, the optical model usually provides the basic underpinning of analyses directed at data for applications. An overview is given here of experience in the Nuclear Theory and Applications Group at Los Alamos National Laboratory in the use of the optical model for calculations of nuclear cross section data for applied purposes. We consider the direct utilization of total, elastic, and reaction cross sections for neutrons, protons, deuterons, tritons, 3 He and alpha particles in files of evaluated nuclear data covering the energy range of 0 to 200 MeV, as well as transmission coefficients for reaction theory calculations and neutron and proton wave functions in direct-reaction and Feshbach-Kerman-Koonin analyses. Optical model codes such as SCAT and ECIS and the reaction theory codes COMNUC, GNASH, FKK-GNASH, and DWUCK have primarily been used in our analyses. A summary of optical model parameterizations from past analyses at Los Alamos will be given, including detailed tabulations of the parameters for a selection of nuclei. (author)
Analytical model for release calculations in solid thin-foils ISOL targets
Energy Technology Data Exchange (ETDEWEB)
Egoriti, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Politecnico di Milano, Department of Energy, CeSNEF-Nuclear Engineering Division, Via Ponzio, 34/3, 20133 Milano (Italy); Boeckx, S. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); ICTEAM Inst., Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium); Ghys, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Houngbo, D., E-mail: donald.houngbo@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Department of Flow, Heat and Combustion Mechanics, Gent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium); Popescu, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium)
2016-10-01
A detailed analytical model has been developed to simulate isotope-release curves from thin-foils ISOL targets. It involves the separate modeling of diffusion and effusion inside the target. The former has been modeled using both first and second Fick's law. The latter, effusion from the surface of the target material to the end of the ionizer, was simulated with the Monte Carlo code MolFlow+. The calculated delay-time distribution for this process was then fitted using a double-exponential function. The release curve obtained from the convolution of diffusion and effusion shows good agreement with experimental data from two different target geometries used at ISOLDE. Moreover, the experimental yields are well reproduced when combining the release fraction with calculated in-target production.
OPT13B and OPTIM4 - computer codes for optical model calculations
International Nuclear Information System (INIS)
Pal, S.; Srivastava, D.K.; Mukhopadhyay, S.; Ganguly, N.K.
1975-01-01
OPT13B is a computer code in FORTRAN for optical model calculations with automatic search. A summary of different formulae used for computation is given. Numerical methods are discussed. The 'search' technique followed to obtain the set of optical model parameters which produce best fit to experimental data in a least-square sense is also discussed. Different subroutines of the program are briefly described. Input-output specifications are given in detail. A modified version of OPT13B specifications are given in detail. A modified version of OPT13B is OPTIM4. It can be used for optical model calculations where the form factors of different parts of the optical potential are known point by point. A brief description of the modifications is given. (author)
Calculating kaon fragmentation functions from the Nambu-Jona-Lasinio jet model
International Nuclear Information System (INIS)
Matevosyan, Hrayr H.; Thomas, Anthony W.; Bentz, Wolfgang
2011-01-01
The Nambu-Jona-Lasinio (NJL)-jet model provides a sound framework for calculating the fragmentation functions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters. Earlier studies of the pion fragmentation functions using the NJL model within this framework showed qualitative agreement with the empirical parametrizations. Here we extend the NJL-jet model by including the strange quark. The corrections to the pion fragmentation functions and corresponding kaon fragmentation functions are calculated using the elementary quark to quark-meson fragmentation functions from NJL. The results for the kaon fragmentation functions exhibit a qualitative agreement with the empirical parametrizations, while the unfavored strange quark fragmentation to pions is shown to be of the same order of magnitude as the unfavored light quark. The results of these studies are expected to provide important guidance for the analysis of a large variety of semi-inclusive data.
Defects in boron carbide: First-principles calculations and CALPHAD modeling
International Nuclear Information System (INIS)
Saengdeejing, Arkapol; Saal, James E.; Manga, Venkateswara Rao; Liu Zikui
2012-01-01
The energetics of defects in B 4+x C boron carbide and β-boron are studied through first-principles calculations, the supercell phonon approach and the Debye–Grüneisen model. It is found that suitable sublattice models for β-boron and B 4+x C are B 101 (B,C) 4 and B 11 (B,C) (B,C,Va) (B,Va) (B,C,Va), respectively. The thermodynamic properties of B 4+x C, β-boron, liquid and graphite are modeled using the CALPHAD approach based on the thermochemical data from first-principles calculations and experimental phase equilibrium data in the literature. The concentrations of various defects are then predicted as a function of carbon composition and temperature.
Molecular Modeling for Calculation of Mechanical Properties of Epoxies with Moisture Ingress
Clancy, Thomas C.; Frankland, Sarah J.; Hinkley, J. A.; Gates, T. S.
2009-01-01
Atomistic models of epoxy structures were built in order to assess the effect of crosslink degree, moisture content and temperature on the calculated properties of a typical representative generic epoxy. Each atomistic model had approximately 7000 atoms and was contained within a periodic boundary condition cell with edge lengths of about 4 nm. Four atomistic models were built with a range of crosslink degree and moisture content. Each of these structures was simulated at three temperatures: 300 K, 350 K, and 400 K. Elastic constants were calculated for these structures by monitoring the stress tensor as a function of applied strain deformations to the periodic boundary conditions. The mechanical properties showed reasonably consistent behavior with respect to these parameters. The moduli decreased with decreasing crosslink degree with increasing temperature. The moduli generally decreased with increasing moisture content, although this effect was not as consistent as that seen for temperature and crosslink degree.
International Nuclear Information System (INIS)
Caon, M.
2010-01-01
Full text: Medical imaging provides two-dimensional pictures of the human internal anatomy from which may be constructed a three-dimensional model of organs and tissues suitable for calculation of dose from radiation. Diagnostic CT provides the greatest exposure to radiation per examination and the frequency of CT examination is high. Esti mates of dose from diagnostic radiography are still determined from data derived from geometric models (rather than anatomical models), models scaled from adult bodies (rather than bodies of children) and CT scanner hardware that is no longer used. The aim of anatomical modelling is to produce a mathematical representation of internal anatomy that has organs of realistic size, shape and positioning. The organs and tissues are represented by a great many cuboidal volumes (voxels). The conversion of medical images to voxels is called segmentation and on completion every pixel in an image is assigned to a tissue or organ. Segmentation is time consuming. An image processing pack age is used to identify organ boundaries in each image. Thirty to forty tomographic voxel models of anatomy have been reported in the literature. Each model is of an individual, or a composite from several individuals. Images of children are particularly scarce. So there remains a need for more paediatric anatomical models. I am working on segmenting ''William'' who is 368 PET-CT images from head to toe of a seven year old boy. William will be used for Monte Carlo dose calculations of dose from CT examination using a simulated modern CT scanner.
Performance of a Predictive Model for Calculating Ascent Time to a Target Temperature
Directory of Open Access Journals (Sweden)
Jin Woo Moon
2016-12-01
Full Text Available The aim of this study was to develop an artificial neural network (ANN prediction model for controlling building heating systems. This model was used to calculate the ascent time of indoor temperature from the setback period (when a building was not occupied to a target setpoint temperature (when a building was occupied. The calculated ascent time was applied to determine the proper moment to start increasing the temperature from the setback temperature to reach the target temperature at an appropriate time. Three major steps were conducted: (1 model development; (2 model optimization; and (3 performance evaluation. Two software programs—Matrix Laboratory (MATLAB and Transient Systems Simulation (TRNSYS—were used for model development, performance tests, and numerical simulation methods. Correlation analysis between input variables and the output variable of the ANN model revealed that two input variables (current indoor air temperature and temperature difference from the target setpoint temperature, presented relatively strong relationships with the ascent time to the target setpoint temperature. These two variables were used as input neurons. Analyzing the difference between the simulated and predicted values from the ANN model provided the optimal number of hidden neurons (9, hidden layers (3, moment (0.9, and learning rate (0.9. At the study’s conclusion, the optimized model proved its prediction accuracy with acceptable errors.
Statistics and integral experiments in the verification of LOCA calculations models
International Nuclear Information System (INIS)
Margolis, S.G.
1978-01-01
The LOCA (loss of coolant accident) is a hypothesized, low-probability accident used as a licensing basis for nuclear power plants. Computer codes which have been under development for at least a decade have been the principal tools used to assess the consequences of the hypothesized LOCA. Models exist in two versions. In EM's (Evaluation Models) the basic engineering calculations are constrained by a detailed set of assumptions spelled out in the Code of Federal Regulations (10 CFR 50, Appendix K). In BE Models (Best Estimate Models) the calculations are based on fundamental physical laws and available empirical correlations. Evaluation models are intended to have a pessimistic bias; Best Estimate Models are intended to be unbiased. Because evaluation models play a key role in reactor licensing, they must be conservative. A long-sought objective has been to assess this conservatism by combining Best Estimate Models with statisticallly established error bounds, based on experiment. Within the last few years, an extensive international program of LOCA experiments has been established to provide the needed data. This program has already produced millions of measurements of temperature, density, and flow and millions of more measurements are yet to come
Lengers, Bernd; Schiefler, Inga; Büscher, Wolfgang
2013-12-01
The overall measurement of farm level greenhouse gas (GHG) emissions in dairy production is not feasible, from either an engineering or administrative point of view. Instead, computational model systems are used to generate emission inventories, demanding a validation by measurement data. This paper tests the GHG calculation of the dairy farm-level optimization model DAIRYDYN, including methane (CH₄) from enteric fermentation and managed manure. The model involves four emission calculation procedures (indicators), differing in the aggregation level of relevant input variables. The corresponding emission factors used by the indicators range from default per cow (activity level) emissions up to emission factors based on feed intake, manure amount, and milk production intensity. For validation of the CH₄ accounting of the model, 1-year CH₄ measurements of an experimental free-stall dairy farm in Germany are compared to model simulation results. An advantage of this interdisciplinary study is given by the correspondence of the model parameterization and simulation horizon with the experimental farm's characteristics and measurement period. The results clarify that modeled emission inventories (2,898, 4,637, 4,247, and 3,600 kg CO₂-eq. cow(-1) year(-1)) lead to more or less good approximations of online measurements (average 3,845 kg CO₂-eq. cow(-1) year(-1) (±275 owing to manure management)) depending on the indicator utilized. The more farm-specific characteristics are used by the GHG indicator; the lower is the bias of the modeled emissions. Results underline that an accurate emission calculation procedure should capture differences in energy intake, owing to milk production intensity as well as manure storage time. Despite the differences between indicator estimates, the deviation of modeled GHGs using detailed indicators in DAIRYDYN from on-farm measurements is relatively low (between -6.4% and 10.5%), compared with findings from the literature.
International Nuclear Information System (INIS)
Palau, J.M.; Cathalau, S.; Hudelot, J.P.; Barran, F.; Bellanger, V.; Magnaud, C.; Moreau, F.
2011-01-01
Burnable poisons are extensively used by Light Water Reactor designers in order to preserve the fuel reactivity potential and increase the cycle length (without increasing the uranium enrichment). In the industrial two-steps (assembly 2D transport-core 3D diffusion) calculation schemes these heterogeneities yield to strong flux and cross-sections perturbations that have to be taken into account in the final 3D burn-up calculations. This paper presents the application of an enhanced cross-section interpolation model (implemented in the French CRONOS2 code) to LWR (highly poisoned) depleted core calculations. The principle is to use the absorbers (or actinide) concentrations as the new interpolation parameters instead of the standard local burnup/fluence parameters. It is shown by comparing the standard (burnup/fluence) and new (concentration) interpolation models and using the lattice transport code APOLLO2 as a numerical reference that reactivity and local reaction rate prediction of a 2x2 LWR assembly configuration (slab geometry) is significantly improved with the concentration interpolation model. Gains on reactivity and local power predictions (resp. more than 1000 pcm and 20 % discrepancy reduction compared to the reference APOLLO2 scheme) are obtained by using this model. In particular, when epithermal absorbers are inserted close to thermal poison the 'shadowing' ('screening') spectral effects occurring during control operations are much more correctly modeled by concentration parameters. Through this outstanding example it is highlighted that attention has to be paid to the choice of cross-section interpolation parameters (burnup 'indicator') in core calculations with few energy groups and variable geometries all along the irradiation cycle. Actually, this new model could be advantageously applied to steady-state and transient LWR heterogeneous core computational analysis dealing with strong spectral-history variations under
A four-equation friction model for water hammer calculation in quasi-rigid pipelines
International Nuclear Information System (INIS)
Ghodhbani, Abdelaziz; Haj Taïeb, Ezzeddine
2017-01-01
Friction coupling affects water hammer evolution in pipelines according to the initial flow regime. Unsteady friction models are only validated with uncoupled formulation. On the other hand, coupled models such as four-equation model, provide more accurate prediction of water hammer since fluid-structure interaction (FSI) is taken into account, but they are limited to steady-state friction formulation. This paper deals with the creation of the “four-equation friction model” which is based on the incorporation of the unsteady head loss given by an unsteady friction model into the four-equation model. For transient laminar flow cases, the Zielke model is considered. The proposed model is applied to a quasi-rigid pipe with axial moving valve, and then calculated by the method of characteristics (MOC). Damping and shape of the numerical solution are in good agreement with experimental data. Thus, the proposed model can be incorporated into a new computer code. - Highlights: • Both Zielke model and four-equation model are insufficient to predict water hammer. • The four-equation friction model proposed is obtained by incorporating the unsteady head loss in the four-equation model. • The solution obtained by the proposed model is in good agreement with experimental data. • The wave-speed adjustment scheme is more efficient than interpolations schemes.
Study of slab fuel cell models for reactor core neutronic calculation
International Nuclear Information System (INIS)
Claro, Luiz H.; Ono, Shizuca; Nascimento, Jamil A.; Vieira, Wilson J.; Caldeira, Alexandre D.; Dias, Artur Flavio
2005-01-01
In this work some models for a slab cell of a nuclear reactor are studied. Two methodologies are used: the deterministic through WIMS code, and the probabilistic one through MCNP code. The objective is to define the best geometric model for a fuel cell to be applied in a cell calculation to be carried through the WIMS code and to use the MCNP code as reference. The results had indicated that for the one-dimensional model the slab fuel cell with only three regions is the best option with a fuel region, a cladding region and a moderator region. (author)
Surface water management: a user's guide to calculate a water balance using the CREAMS model
International Nuclear Information System (INIS)
Lane, L.J.
1984-11-01
The hydrologic component of the CREAMS model is described and discussed in terms of calculating a surface water balance for shallow land burial systems used for waste disposal. Parameter estimates and estimation procedures are presented in detail in the form of a user's guide. Use of the model is illustrated with three examples based on analysis of data from Los Alamos, New Mexico and Rock Valley, Nevada. Use of the model in design of trench caps for shallow land burial systems is illustrated with the example applications at Los Alamos
International Nuclear Information System (INIS)
Singh, Vishal; Modi, Swati; Arumugam, P.
2017-01-01
Recent advancements in accelerator technology and polarized beams have created opportunities to study oriented collisions of deformed targets. We extend the Glauber model to calculate the interaction cross section for a spherical projectile and a deformed target at different orientation angles of the target. It has been found that the observed reaction cross sections of various systems at high energies can be reproduced with this model. We have used the relativistic mean field (RMF) theory to find the density distribution of nucleons in the projectile and target which are utilised in the Glauber model. We present the variation of interaction cross section of target and projectile with the orientation of deformed target
The High Level Mathematical Models in Calculating Aircraft Gas Turbine Engine Parameters
Directory of Open Access Journals (Sweden)
Yu. A. Ezrokhi
2017-01-01
Full Text Available The article describes high-level mathematical models developed to solve special problems arising at later stages of design with regard to calculation of the aircraft gas turbine engine (GTE under real operating conditions. The use of blade row mathematics models, as well as mathematical models of a higher level, including 2D and 3D description of the working process in the engine units and components, makes it possible to determine parameters and characteristics of the aircraft engine under conditions significantly different from the calculated ones.The paper considers application of mathematical modelling methods (MMM for solving a wide range of practical problems, such as forcing the engine by injection of water into the flowing part, estimate of the thermal instability effect on the GTE characteristics, simulation of engine start-up and windmill starting condition, etc. It shows that the MMM use, when optimizing the laws of the compressor stator control, as well as supplying cooling air to the hot turbine components in the motor system, can significantly improve the integral traction and economic characteristics of the engine in terms of its gas-dynamic stability, reliability and resource.It ought to bear in mind that blade row mathematical models of the engine are designed to solve purely "motor" problems and do not replace the existing models of various complexity levels used in calculation and design of compressors and turbines, because in “quality” a description of the working processes in these units is inevitably inferior to such specialized models.It is shown that the choice of the mathematical modelling level of an aircraft engine for solving a particular problem arising in its designing and computational study is to a large extent a compromise problem. Despite the significantly higher "resolution" and information ability the motor mathematical models containing 2D and 3D approaches to the calculation of flow in blade machine
Model for calculating shock loading and release paths for multicomponent geologic media
International Nuclear Information System (INIS)
Butkovich, T.R.; Moran, B.; Burton, D.E.
1981-07-01
A model has been devised to calculate shock Hugoniots and release paths off the Hugoniots for multicomponent rocks containing silicate, carbonate, and water. Hugoniot equations of state are constructed from relatively simple measurements of rock properties including bulk density, grain density of the silicate component, and weight fractions of water and carbonate. Release paths off the composite Hugoniot are calculated by mixing release paths off the component Hugoniots according to their weight fractions. If the shock imparts sufficient energy to the component to cause vaporization, a gas equation of state is used to calculate the release paths. For less energetic shocks, the rock component will unload like a solid or liquid, taking into account the irreversible removal of air-filled porosity
Polystochastic Models for Complexity
Iordache, Octavian
2010-01-01
This book is devoted to complexity understanding and management, considered as the main source of efficiency and prosperity for the next decades. Divided into six chapters, the book begins with a presentation of basic concepts as complexity, emergence and closure. The second chapter looks to methods and introduces polystochastic models, the wave equation, possibilities and entropy. The third chapter focusing on physical and chemical systems analyzes flow-sheet synthesis, cyclic operations of separation, drug delivery systems and entropy production. Biomimetic systems represent the main objective of the fourth chapter. Case studies refer to bio-inspired calculation methods, to the role of artificial genetic codes, neural networks and neural codes for evolutionary calculus and for evolvable circuits as biomimetic devices. The fifth chapter, taking its inspiration from systems sciences and cognitive sciences looks to engineering design, case base reasoning methods, failure analysis, and multi-agent manufacturing...
Quark model calculation of the parity violating NNπ coupling in the Weinberg-Salam model
International Nuclear Information System (INIS)
Koerner, J.G.; Kramer, G.; Willrodt, J.
1978-10-01
We argue that there are no charged current contributions to the parity violating NNπ coupling except for small contributions from flavour symmetry breaking effects. From the neutral current product only the left-right chiral component contributes which is considerably enhanced due to gluon corrections and due to the lightness of current quark masses. The resulting parity violating NNπ coupling has a definite phase and is 10 times stronger than the value used previously in nuclear physics calculations. (orig.) [de
Fast pencil beam dose calculation for proton therapy using a double-Gaussian beam model
Directory of Open Access Journals (Sweden)
Joakim eda Silva
2015-12-01
Full Text Available The highly conformal dose distributions produced by scanned proton pencil beams are more sensitive to motion and anatomical changes than those produced by conventional radiotherapy. The ability to calculate the dose in real time as it is being delivered would enable, for example, online dose monitoring, and is therefore highly desirable. We have previously described an implementation of a pencil beam algorithm running on graphics processing units (GPUs intended specifically for online dose calculation. Here we present an extension to the dose calculation engine employing a double-Gaussian beam model to better account for the low-dose halo. To the best of our knowledge, it is the first such pencil beam algorithm for proton therapy running on a GPU. We employ two different parametrizations for the halo dose, one describing the distribution of secondary particles from nuclear interactions found in the literature and one relying on directly fitting the model to Monte Carlo simulations of pencil beams in water. Despite the large width of the halo contribution, we show how in either case the second Gaussian can be included whilst prolonging the calculation of the investigated plans by no more than 16%, or the calculation of the most time-consuming energy layers by about 25%. Further, the calculation time is relatively unaffected by the parametrization used, which suggests that these results should hold also for different systems. Finally, since the implementation is based on an algorithm employed by a commercial treatment planning system, it is expected that with adequate tuning, it should be able to reproduce the halo dose from a general beam line with sufficient accuracy.
Study on the Calculation Models of Bus Delay at Bays Using Queueing Theory and Markov Chain
Directory of Open Access Journals (Sweden)
Feng Sun
2015-01-01
Full Text Available Traffic congestion at bus bays has decreased the service efficiency of public transit seriously in China, so it is crucial to systematically study its theory and methods. However, the existing studies lack theoretical model on computing efficiency. Therefore, the calculation models of bus delay at bays are studied. Firstly, the process that buses are delayed at bays is analyzed, and it was found that the delay can be divided into entering delay and exiting delay. Secondly, the queueing models of bus bays are formed, and the equilibrium distribution functions are proposed by applying the embedded Markov chain to the traditional model of queuing theory in the steady state; then the calculation models of entering delay are derived at bays. Thirdly, the exiting delay is studied by using the queueing theory and the gap acceptance theory. Finally, the proposed models are validated using field-measured data, and then the influencing factors are discussed. With these models the delay is easily assessed knowing the characteristics of the dwell time distribution and traffic volume at the curb lane in different locations and different periods. It can provide basis for the efficiency evaluation of bus bays.
DIDEM - An integrated model for comparative health damage costs calculation of air pollution
Ravina, Marco; Panepinto, Deborah; Zanetti, Maria Chiara
2018-01-01
Air pollution represents a continuous hazard to human health. Administration, companies and population need efficient indicators of the possible effects given by a change in decision, strategy or habit. The monetary quantification of health effects of air pollution through the definition of external costs is increasingly recognized as a useful indicator to support decision and information at all levels. The development of modelling tools for the calculation of external costs can provide support to analysts in the development of consistent and comparable assessments. In this paper, the DIATI Dispersion and Externalities Model (DIDEM) is presented. The DIDEM model calculates the delta-external costs of air pollution comparing two alternative emission scenarios. This tool integrates CALPUFF's advanced dispersion modelling with the latest WHO recommendations on concentration-response functions. The model is based on the impact pathway method. It was designed to work with a fine spatial resolution and a local or national geographic scope. The modular structure allows users to input their own data sets. The DIDEM model was tested on a real case study, represented by a comparative analysis of the district heating system in Turin, Italy. Additional advantages and drawbacks of the tool are discussed in the paper. A comparison with other existing models worldwide is reported.
Iron -chromium alloys and free surfaces: from ab initio calculations to thermodynamic modeling
International Nuclear Information System (INIS)
Levesque, M.
2010-11-01
Ferritic steels possibly strengthened by oxide dispersion are candidates as structural materials for generation IV and fusion nuclear reactors. Their use is limited by incomplete knowledge of the iron-chromium phase diagram at low temperatures and of the phenomena inducing preferential segregation of one element at grain boundaries or at surfaces. In this context, this work contributes to the multi-scale study of the model iron-chromium alloy and their free surfaces by numerical simulations. This study begins with ab initio calculations of properties related to the mixture of atoms of iron and chromium. We highlight complex dependency of the magnetic moments of the chromium atoms on their local chemical environment. Surface properties are also proving sensitive to magnetism. This is the case of impurity segregation of chromium in iron and of their interactions near the surface. In a second step, we construct a simple energy model for high numerical efficiency. It is based on pair interactions on a rigid lattice to which are given local chemical environment and temperature dependencies. With this model, we reproduce the ab initio results at zero temperature and experimental results at high temperature. We also deduce the solubility limits at all intermediate temperatures with mean field approximations that we compare to Monte Carlo simulations. The last step of our work is to introduce free surfaces in our model. We then study the effect of ab initio calculated bulk and surface properties on surface segregation.Finally, we calculate segregation isotherms. We therefore propose an evolution model of surface composition of iron-chromium alloys as a function of bulk composition. which are given local chemical environment and temperature dependencies. With this model, we reproduce the ab initio results at zero temperature and experimental results at high temperature. We also deduce the solubility limits at all intermediate temperatures with mean field approximations that
Modelling of electron contamination in clinical photon beams for Monte Carlo dose calculation
International Nuclear Information System (INIS)
Yang, J; Li, J S; Qin, L; Xiong, W; Ma, C-M
2004-01-01
The purpose of this work is to model electron contamination in clinical photon beams and to commission the source model using measured data for Monte Carlo treatment planning. In this work, a planar source is used to represent the contaminant electrons at a plane above the upper jaws. The source size depends on the dimensions of the field size at the isocentre. The energy spectra of the contaminant electrons are predetermined using Monte Carlo simulations for photon beams from different clinical accelerators. A 'random creep' method is employed to derive the weight of the electron contamination source by matching Monte Carlo calculated monoenergetic photon and electron percent depth-dose (PDD) curves with measured PDD curves. We have integrated this electron contamination source into a previously developed multiple source model and validated the model for photon beams from Siemens PRIMUS accelerators. The EGS4 based Monte Carlo user code BEAM and MCSIM were used for linac head simulation and dose calculation. The Monte Carlo calculated dose distributions were compared with measured data. Our results showed good agreement (less than 2% or 2 mm) for 6, 10 and 18 MV photon beams
Analytical calculation of detailed model parameters of cast resin dry-type transformers
International Nuclear Information System (INIS)
Eslamian, M.; Vahidi, B.; Hosseinian, S.H.
2011-01-01
Highlights: → In this paper high frequency behavior of cast resin dry-type transformers was simulated. → Parameters of detailed model were calculated using analytical method and compared with FEM results. → A lab transformer was constructed in order to compare theoretical and experimental results. -- Abstract: Non-flammable characteristic of cast resin dry-type transformers make them suitable for different kind of usages. This paper presents an analytical method of how to obtain parameters of detailed model of these transformers. The calculated parameters are compared and verified with the corresponding FEM results and if it was necessary, correction factors are introduced for modification of the analytical solutions. Transient voltages under full and chopped test impulses are calculated using the obtained detailed model. In order to validate the model, a setup was constructed for testing on high-voltage winding of cast resin dry-type transformer. The simulation results were compared with the experimental data measured from FRA and impulse tests.
Evolution of calculation models for the proton-therapy dose planning software
International Nuclear Information System (INIS)
Vidal, Marie
2011-01-01
This work was achieved in collaboration between the Institut Curie Proton-therapy Center of Orsay (ICPO), the DOSIsoft company and the CREATIS laboratory, in order to develop a new dose calculation model for the new ICPO treatment room. A new accelerator and gantry room from the IBA company were installed during the up-grade project of the proton-therapy center, with the intention of enlarging the cancer localizations treated at ICPO. Developing a package of methods and new dose calculation algorithms to adapt them to the new specific characteristics of the delivered beams by the IBA system is the first goal of this PhD work. They all aim to be implemented in the DOSIsoft treatment planning software, Isogray. First, the double scattering technique is treated in taking into account major differences between the IBA system and the ICPO fixed beam lines passive system. Secondly, a model is explored for the scanned beams modality. The second objective of this work is improving the Ray-Tracing and Pencil-Beam dose calculation models already in use. For the double scattering and uniform scanning techniques, the patient personalized collimator at the end of the beam line causes indeed a patient dose distribution contamination. A reduction method of that phenomenon was set up for the passive beam system. An analytical model was developed which describes the contamination function with parameters validated through Monte-Carlo simulations on the GATE platform. It allows us to apply those methods to active scanned beams. (author) [fr
Evolution of dose calculation models for proton-therapy treatment planning
International Nuclear Information System (INIS)
Vidal, Marie
2011-01-01
This work was achieved in collaboration between the Institut Curie proton-therapy Center of Orsay (ICPO), the DOSIsoft company and the CREATIS laboratory, in order to develop a new dose calculation model for the new ICPO treatment room. A new accelerator and gantry room from the IBA company were installed during the up-grade project of the proton-therapy center, with the intention of enlarging the cancer localizations treated at ICPO. Developing a package of methods and new dose calculation algorithms to adapt them to the new specific characteristics of the delivered beams by the IBA system is the first goal of this PhD work. They all aim to be implemented in the DOSIsoft treatment planning software, Isogray. First, the double scattering technique is treated in taking into account major differences between the IBA system and the ICPO fixed beam lines passive system. Secondly, a model is explored for the scanned beams modality. The second objective of this work is improving the Ray-Tracing and Pencil-Beam dose calculation models already in use. For the double scattering and uniform scanning techniques, the patient personalized collimator at the end of the beam line causes indeed a patient dose distribution contamination. A reduction method of that phenomenon was set up for the passive beam system. An analytical model was developed which describes the contamination function with parameters validated through Monte-Carlo simulations on the GATE platform. It allows us to apply those methods to active scanned beams [fr
A calculation model for primary intensity distributions from cylindrically symmetric x-ray lenses
International Nuclear Information System (INIS)
Hristov, Dimitre; Maltz, Jonathan
2008-01-01
A calculation model for the quantitative prediction of primary intensity fluence distributions obtained by the Bragg diffraction focusing of kilovoltage radiation by cylindrical x-ray lenses is presented. The mathematical formalism describes primary intensity distributions from cylindrically-symmetric x-ray lenses, with a planar isotropic radiation source located in a plane perpendicular to the lens axis. The presence of attenuating medium inserted between the lens and the lens focus is accounted for by energy-dependent attenuation. The influence of radiation scattered within the media is ignored. Intensity patterns are modeled under the assumption that photons that are not interacting with the lens are blocked out at any point of interest. The main characteristics of the proposed calculation procedure are that (i) the application of vector formalism allows universal treatment of all cylindrical lenses without the need of explicit geometric constructs; (ii) intensity distributions resulting from x-ray diffraction are described by a 3D generalization of the mosaic spread concept; (iii) the calculation model can be immediately coupled to x-ray diffraction simulation packages such as XOP and Shadow. Numerical simulations based on this model are to facilitate the design of focused orthovoltage treatment (FOT) systems employing cylindrical x-ray lenses, by providing insight about the influence of the x-ray source and lens parameters on quantities of dosimetric interest to radiation therapy
International Nuclear Information System (INIS)
Kalin, J.; Petkovsek, B.; Montarnal, Ph.; Genty, A.; Deville, E.; Krivic, J.; Ratej, J.
2011-01-01
In the past years the Slovenian Performance Analysis/Safety Assessment team has performed many generic studies for the future Slovenian low and intermediate level waste repository, most recently a Special Safety Analysis for the Krsko site. The modelling approach was to split the problem into three parts: near-field (detailed model of the repository), far-field (i.e., geosphere) and biosphere. In the Special Safety Analysis the code used to perform the near-field calculations was Hydrus2D. Recently the team has begun a cooperation with the French Commisariat al'Energie Atomique/Saclay (CEA/Saclay) and, as a part of this cooperation, began investigations into using the Alliances numerical platform for near-field calculations in order to compare the overall approach and calculated results. The article presents the comparison between these two codes for a silo-type repository that was considered in the Special Safety Analysis. The physical layout and characteristics of the repository are presented and a hydraulic and transport model of the repository is developed and implemented in Alliances. Some analysis of sensitivity to mesh fineness and to simulation timestep has been preformed and is also presented. The compared quantity is the output flux of radionuclides on the boundary of the model. Finally the results from Hydrus2D and Alliances are compared and the differences and similarities are commented.
Energy Technology Data Exchange (ETDEWEB)
Kalin, J., E-mail: jan.kalin@zag.s [Slovenian National Building and Civil Engineering Institute, Dimiceva 12, SI-1000 Ljubljana (Slovenia); Petkovsek, B., E-mail: borut.petkovsek@zag.s [Slovenian National Building and Civil Engineering Institute, Dimiceva 12, SI-1000 Ljubljana (Slovenia); Montarnal, Ph., E-mail: philippe.montarnal@cea.f [CEA/Saclay, DM2S/SFME/LSET, Gif-sur-Yvette, 91191 cedex (France); Genty, A., E-mail: alain.genty@cea.f [CEA/Saclay, DM2S/SFME/LSET, Gif-sur-Yvette, 91191 cedex (France); Deville, E., E-mail: estelle.deville@cea.f [CEA/Saclay, DM2S/SFME/LSET, Gif-sur-Yvette, 91191 cedex (France); Krivic, J., E-mail: jure.krivic@geo-zs.s [Geological Survey of Slovenia, Dimiceva 14, SI-1000 Ljubljana (Slovenia); Ratej, J., E-mail: joze.ratej@geo-zs.s [Geological Survey of Slovenia, Dimiceva 14, SI-1000 Ljubljana (Slovenia)
2011-04-15
In the past years the Slovenian Performance Analysis/Safety Assessment team has performed many generic studies for the future Slovenian low and intermediate level waste repository, most recently a Special Safety Analysis for the Krsko site. The modelling approach was to split the problem into three parts: near-field (detailed model of the repository), far-field (i.e., geosphere) and biosphere. In the Special Safety Analysis the code used to perform the near-field calculations was Hydrus2D. Recently the team has begun a cooperation with the French Commisariat al'Energie Atomique/Saclay (CEA/Saclay) and, as a part of this cooperation, began investigations into using the Alliances numerical platform for near-field calculations in order to compare the overall approach and calculated results. The article presents the comparison between these two codes for a silo-type repository that was considered in the Special Safety Analysis. The physical layout and characteristics of the repository are presented and a hydraulic and transport model of the repository is developed and implemented in Alliances. Some analysis of sensitivity to mesh fineness and to simulation timestep has been preformed and is also presented. The compared quantity is the output flux of radionuclides on the boundary of the model. Finally the results from Hydrus2D and Alliances are compared and the differences and similarities are commented.
MATHEMATICAL MODEL FOR CALCULATION OF INFORMATION RISKS FOR INFORMATION AND LOGISTICS SYSTEM
Directory of Open Access Journals (Sweden)
A. G. Korobeynikov
2015-05-01
Full Text Available Subject of research. The paper deals with mathematical model for assessment calculation of information risks arising during transporting and distribution of material resources in the conditions of uncertainty. Meanwhile information risks imply the danger of origin of losses or damage as a result of application of information technologies by the company. Method. The solution is based on ideology of the transport task solution in stochastic statement with mobilization of mathematical modeling theory methods, the theory of graphs, probability theory, Markov chains. Creation of mathematical model is performed through the several stages. At the initial stage, capacity on different sites depending on time is calculated, on the basis of information received from information and logistic system, the weight matrix is formed and the digraph is under construction. Then there is a search of the minimum route which covers all specified vertexes by means of Dejkstra algorithm. At the second stage, systems of differential Kolmogorov equations are formed using information about the calculated route. The received decisions show probabilities of resources location in concrete vertex depending on time. At the third stage, general probability of the whole route passing depending on time is calculated on the basis of multiplication theorem of probabilities. Information risk, as time function, is defined by multiplication of the greatest possible damage by the general probability of the whole route passing. In this case information risk is measured in units of damage which corresponds to that monetary unit which the information and logistic system operates with. Main results. Operability of the presented mathematical model is shown on a concrete example of transportation of material resources where places of shipment and delivery, routes and their capacity, the greatest possible damage and admissible risk are specified. The calculations presented on a diagram showed
Shell model calculations for levels and transition rates in 204Pb and 206Pb
International Nuclear Information System (INIS)
Wang, D.; McEllistrem, M.T.
1990-01-01
Level energies and decay rates of both negative and positive parity levels of 206,204 Pb have been calculated through mixed-configuration shell model calculations using the modified surface delta interaction (MSDI), the Schiffer-True central interaction, and another two-body interaction. These calculations were all carried out with a full six-orbit neutron hole space. The predicted low-lying levels with the MSDI are in excellent agreement with experiments, accounting for the energies, spins, and parities of essentially all levels below 3 MeV excitation energy except known particle-hole collective excitations in both nuclei. Almost all calculated E2 and M1 transition rates are consistent with measured branching ratios for γ-ray decay of excited levels. The comparison of the observed and calculated levels demonstrates the important role played by the neutron-hole i 13/2 configuration in the levels of 204 Pb and 206 Pb, and interprets an apparent discrepancy over the character and energy spacings of 0 + levels in 204 Pb
WIMS calculations for a model CAGR skip containing clusters and loose pins
International Nuclear Information System (INIS)
Halsall, M.J.
1982-12-01
Calculations using WIMSD4 and MONK5.3 assess the reactivity consequences of distributing loose fuel pins around a CAGR skip already loaded with 20 fuel clusters, indicated uncertainties in the accuracy of the WIMSD4 multicell option for establishing the worst distribution of loose pins. The present study was undertaken in an attempt to resolve this uncertainty by comparing WIMSD4 single cell and multicell calculations for a representative model problem with results derived from LWRWIMS using discrete ordinates transport theory TWOTRAN to give a more reliable estimate of inter-cell couplings. The study concludes that WIMSD4 is systematic in its treatment of single cells with loose pins added but that somewhat unpredictable discrepancies of the order of 1 per cent in k can arise in calculations of different arrangements of cell types in a multicell situation. This is, nevertheless, of comparable accuracy to the Monte Carlo calculations normally made for studies of this type and hence the relatively rapid WIMSD4 calculations should serve a useful function in deciding which situations to analyse in more detail. (U.K.)
Development and application of the PBMR fission product release calculation model
International Nuclear Information System (INIS)
Merwe, J.J. van der; Clifford, I.
2008-01-01
At PBMR, long-lived fission product release from spherical fuel spheres is calculated using the German legacy software product GETTER. GETTER is a good tool when performing calculations for fuel spheres under controlled operating conditions, including irradiation tests and post-irradiation heat-up experiments. It has proved itself as a versatile reactor analysis tool, but is rather cumbersome when used for accident and sensitivity analysis. Developments in depressurized loss of forced cooling (DLOFC) accident analysis using GETTER led to the creation of FIssion Product RElease under accident (X) conditions (FIPREX), and later FIPREX-GETTER. FIPREX-GETTER is designed as a wrapper around GETTER so that calculations can be carried out for large numbers of fuel spheres with design and operating parameters that can be stochastically varied. This allows full Monte Carlo sensitivity analyses to be performed for representative cores containing many fuel spheres. The development process and application of FIPREX-GETTER in reactor analysis at PBMR is explained and the requirements for future developments of the code are discussed. Results are presented for a sample PBMR core design under normal operating conditions as well as a suite of design-base accident events, illustrating the functionality of FIPREX-GETTER. Monte Carlo sensitivity analysis principles are explained and presented for each calculation type. The plan and current status of verification and validation (V and V) is described. This is an important and necessary process for all software and calculation model development at PBMR
Fission cross-section calculations and the multi-modal fission model
International Nuclear Information System (INIS)
Hambsch, F.J.
2004-01-01
New, self consistent, neutron-induced reaction cross section calculations for 235,238 U, 237 Np have been performed. The statistical model code STATIS was improved to take into account the multimodality of the fission process. The three most dominant fission modes, the two asymmetric standards I (S1) and standard II (S2) modes and the symmetric superlong (SL) mode have been taken into account. De-convoluted fission cross sections for those modes for 235,238 U(n,f) and 237 Np(n,f) based on experimental branching ratios, were calculated for the first time up to the second chance fission threshold. For 235 U(n,f), the calculations being made up to 28 MeV incident neutron energy, higher fission chances have been considered. This implied the need for additional calculations for the neighbouring isotopes. As a side product also mass yield distributions could be calculated at energies hitherto not accessible by experiment. Experimental validation of the predictions is being envisaged
Calculation of accurate small angle X-ray scattering curves from coarse-grained protein models
Directory of Open Access Journals (Sweden)
Stovgaard Kasper
2010-08-01
Full Text Available Abstract Background Genome sequencing projects have expanded the gap between the amount of known protein sequences and structures. The limitations of current high resolution structure determination methods make it unlikely that this gap will disappear in the near future. Small angle X-ray scattering (SAXS is an established low resolution method for routinely determining the structure of proteins in solution. The purpose of this study is to develop a method for the efficient calculation of accurate SAXS curves from coarse-grained protein models. Such a method can for example be used to construct a likelihood function, which is paramount for structure determination based on statistical inference. Results We present a method for the efficient calculation of accurate SAXS curves based on the Debye formula and a set of scattering form factors for dummy atom representations of amino acids. Such a method avoids the computationally costly iteration over all atoms. We estimated the form factors using generated data from a set of high quality protein structures. No ad hoc scaling or correction factors are applied in the calculation of the curves. Two coarse-grained representations of protein structure were investigated; two scattering bodies per amino acid led to significantly better results than a single scattering body. Conclusion We show that the obtained point estimates allow the calculation of accurate SAXS curves from coarse-grained protein models. The resulting curves are on par with the current state-of-the-art program CRYSOL, which requires full atomic detail. Our method was also comparable to CRYSOL in recognizing native structures among native-like decoys. As a proof-of-concept, we combined the coarse-grained Debye calculation with a previously described probabilistic model of protein structure, TorusDBN. This resulted in a significant improvement in the decoy recognition performance. In conclusion, the presented method shows great promise for
Comprehensive nuclear model calculations: theory and use of the GNASH code
International Nuclear Information System (INIS)
Young, P.G.; Arthur, E.D.; Chadwick, M.B.
1998-01-01
The theory and operation of the nuclear reaction theory computer code GNASH is described, and detailed instructions are presented for code users. The code utilizes statistical Hauser-Feshbach theory with full angular momentum conservation and includes corrections for preequilibrium effects. This version is expected to be applicable for incident particle energies between 1 keV and 150 MeV and for incident photon energies to 140 MeV. General features of the code, the nuclear models that are utilized, input parameters needed to perform calculations, and the output quantities from typical problems are described in detail. A number of new features compared to previous versions are described in this manual, including the following: (1) inclusion of multiple preequilibrium processes, which allows the model calculations to be performed above 50 MeV; (2) a capability to calculate photonuclear reactions; (3) a method for determining the spin distribution of residual nuclei following preequilibrium reactions; and (4) a description of how preequilibrium spectra calculated with the FKK theory can be utilized (the 'FKK-GNASH' approach). The computational structure of the code and the subroutines and functions that are called are summarized as well. Two detailed examples are considered: 14-MeV neutrons incident on 93 Nb and 12-MeV neutrons incident on 238 U. The former example illustrates a typical calculation aimed at determining neutron, proton, and alpha emission spectra from 14-MeV reactions, and the latter example demonstrates use of the fission model in GNASH. Results from a variety of other cases are illustrated. (author)
Lagrangian Photochemical Box-Model Calculations of Asian Pacific Rim Outflow During TRACE-P
Hamlin, A.; Crawford, J.; Olson, J.; Avery, M.; Sachse, G.; Barrick, J.; Blake, D.; Tan, D.; Sandholm, S.; Kondo, Y.; Singh, H.; Eisele, F.; Zondlo, M.; Flocke, F.; Talbot, R.
2006-12-01
NASA's TRACE-P (TRAnsport and Chemical Evolution over the Pacific) mission was conducted over the northwestern Pacific February-April, 2001. During two transit flights across the Pacific, extensive pollution was observed from an Asian outflow event that split into two branches over the central Pacific, one subsiding and moving southward over the central Pacific and the other continuing eastward in the upper troposphere. The subsiding branch was observed as a widespread stagnant pollution layer between 2 and 4 km over the central Pacific during transit flights from Kona, HI to Guam. In this region, high levels of O3 (70 ppbv), CO (217 ppbv), and NOx (114 pptv) were well in excess of typical values observed during TRACE-P along the Asian coast. Evidence suggests that the subsiding branch experienced extensive photochemical processing compared to the branch that remained at altitude. To examine the processes controlling the chemical evolution of ozone and its precursors in this outflow event, data collected during the TRACE-P mission have been combined with lagrangian photochemical box model calculations. One of the largest sources of uncertainty in these calculations was associated with predicted water vapor levels along the transport trajectories calculated using the HYSPLIT model. Water vapor levels predicted by HYSPLIT trajectory calculations in the subsiding layer ranged from 3390 to 4880 ppm, while the median level observed in the pollution layer was only 637 ppm. Simulations of ozone production and associated radical chemistry differed dramatically when using water vapor levels based on trajectory calculations versus observed water vapor levels. Levels of PAN and HO2NO2, NOx reservoir species, are also influenced by uncertainties in temperature along the trajectories. These results highlight the importance of accurately representing the humidification and warming of subsiding air masses in 3-D chemical- transport models.
System of Modelling and Calculation Analysis of Neutron- Physical Experiments at Fast Reactors
International Nuclear Information System (INIS)
Moiseyev, A.V.
2008-01-01
There is an actual task on storage, processing and analysis of the unique experimental data received on power fast reactors for their subsequent use in projects of fast reactors of new (4.) generation. For modeling and carrying out analysis of experiments the integrated computing system MODEXSYS has been developed. In this system the mechanism for consecutive calculation of a fast reactor states with the detailed description of its components is created. The system includes the database describing fast reactor states, results of neutron-physical characteristics measurements at fast reactor, calculation and benchmark models of experiments and calculation results. In system convenient search means and the special graphics shell are provided. It has Interfaces for processing of calculation results and their analysis. MODEXSYS system has been applied for analysis of three types of experiments at fast reactor: k eff , control rod worth and energy release distribution. The most important results of this analysis are described. Application of MODEXSYS system will raise accuracy and reliability of forecasting of fast reactors neutron-physical characteristics; for BN-600 reactor recommended level of accuracy is resulted. (authors)
Application of a Monte Carlo linac model in routine verifications of dose calculations
International Nuclear Information System (INIS)
Linares Rosales, H. M.; Alfonso Laguardia, R.; Lara Mas, E.; Popescu, T.
2015-01-01
The analysis of some parameters of interest in Radiotherapy Medical Physics based on an experimentally validated Monte Carlo model of an Elekta Precise lineal accelerator, was performed for 6 and 15 Mv photon beams. The simulations were performed using the EGSnrc code. As reference for simulations, the optimal beam parameters values (energy and FWHM) previously obtained were used. Deposited dose calculations in water phantoms were done, on typical complex geometries commonly are used in acceptance and quality control tests, such as irregular and asymmetric fields. Parameters such as MLC scatter, maximum opening or closing position, and the separation between them were analyzed from calculations in water. Similarly simulations were performed on phantoms obtained from CT studies of real patients, making comparisons of the dose distribution calculated with EGSnrc and the dose distribution obtained from the computerized treatment planning systems (TPS) used in routine clinical plans. All the results showed a great agreement with measurements, finding all of them within tolerance limits. These results allowed the possibility of using the developed model as a robust verification tool for validating calculations in very complex situation, where the accuracy of the available TPS could be questionable. (Author)
System of Modelling and Calculation Analysis of Neutron- Physical Experiments at Fast Reactors
Energy Technology Data Exchange (ETDEWEB)
Moiseyev, A.V. [SSC RF - IPPE, 1 Bondarenko Square, Obninsk, Kaluga Region 249033 (Russian Federation)
2008-07-01
There is an actual task on storage, processing and analysis of the unique experimental data received on power fast reactors for their subsequent use in projects of fast reactors of new (4.) generation. For modeling and carrying out analysis of experiments the integrated computing system MODEXSYS has been developed. In this system the mechanism for consecutive calculation of a fast reactor states with the detailed description of its components is created. The system includes the database describing fast reactor states, results of neutron-physical characteristics measurements at fast reactor, calculation and benchmark models of experiments and calculation results. In system convenient search means and the special graphics shell are provided. It has Interfaces for processing of calculation results and their analysis. MODEXSYS system has been applied for analysis of three types of experiments at fast reactor: k{sub eff}, control rod worth and energy release distribution. The most important results of this analysis are described. Application of MODEXSYS system will raise accuracy and reliability of forecasting of fast reactors neutron-physical characteristics; for BN-600 reactor recommended level of accuracy is resulted. (authors)
The fast multiple-path NUCTRAN model -- Calculating the radionuclide release from a repository
International Nuclear Information System (INIS)
Romero, L.; Moreno, L.; Neretnieks, I.
1995-01-01
The NUCTRAN model has been applied to the Swedish KBS-3 nuclear waste repository concept, where the migration of radionuclides is through various barriers and pathways. The escape of the nuclides from the canister occurs through a small hole. This hole controls the release of nuclides from the repository. NUCTRAN is a useful tool to calculate the nonstationary transport in a repository for high-level nuclear waste. The advantage of this model is the use of a coarse compartmentalization of the repository, which makes it flexible and easy to adapt to different geometries. The several radionuclide release calculations made with NUCTRAN have shown the capability of this to handle different situations rapidly and easily. The particularity of these calculations is the high accuracy obtained by using a coarse compartmentalization of the Swedish KBS-3 repository and the small requirements of computing time. At short times for short-lived nuclides, the calculated releases are exaggerated. The error can be considerably reduced by an additional subdivision of large compartments into a few compartments
International Nuclear Information System (INIS)
Caon, Martin
2013-01-01
The ADELAIDE voxel model of paediatric anatomy was used with the EGSnrc Monte Carlo code to compare effective dose from computed tomography (CT) calculated with both the ICRP103 and ICRP60 definitions which are different in their tissue weighting factors and in the included tissues. The new tissue weighting factors resulted in a lower effective dose for pelvis CT (than if calculated using ICRP60 tissue weighting factors), by 6.5 % but higher effective doses for all other examinations. ICRP103 calculated effective dose for CT abdomen + pelvis was higher by 4.6 %, for CT abdomen (by 9.5 %), for CT chest + abdomen + pelvis (by 6 %), for CT chest + abdomen (by 9.6 %), for CT chest (by 10.1 %) and for cardiac CT (by 11.5 %). These values, along with published values of effective dose from CT that were calculated for both sets of tissue weighting factors were used to determine single values for the ratio ICRP103:ICRP60 calculated effective doses from CT, for seven CT examinations. The following values for ICRP103:ICRP60 are suggested for use to convert ICRP60 calculated effective dose to ICRP103 calculated effective dose for the following CT examinations: Pelvis CT, 0.75; for abdomen CT, abdomen + pelvis CT, chest + abdomen + pelvis CT, 1.00; for chest + abdomen CT, and for chest CT. 1.15; for cardiac CT 1.25.
SU-F-BRD-09: A Random Walk Model Algorithm for Proton Dose Calculation
International Nuclear Information System (INIS)
Yao, W; Farr, J
2015-01-01
Purpose: To develop a random walk model algorithm for calculating proton dose with balanced computation burden and accuracy. Methods: Random walk (RW) model is sometimes referred to as a density Monte Carlo (MC) simulation. In MC proton dose calculation, the use of Gaussian angular distribution of protons due to multiple Coulomb scatter (MCS) is convenient, but in RW the use of Gaussian angular distribution requires an extremely large computation and memory. Thus, our RW model adopts spatial distribution from the angular one to accelerate the computation and to decrease the memory usage. From the physics and comparison with the MC simulations, we have determined and analytically expressed those critical variables affecting the dose accuracy in our RW model. Results: Besides those variables such as MCS, stopping power, energy spectrum after energy absorption etc., which have been extensively discussed in literature, the following variables were found to be critical in our RW model: (1) inverse squared law that can significantly reduce the computation burden and memory, (2) non-Gaussian spatial distribution after MCS, and (3) the mean direction of scatters at each voxel. In comparison to MC results, taken as reference, for a water phantom irradiated by mono-energetic proton beams from 75 MeV to 221.28 MeV, the gamma test pass rate was 100% for the 2%/2mm/10% criterion. For a highly heterogeneous phantom consisting of water embedded by a 10 cm cortical bone and a 10 cm lung in the Bragg peak region of the proton beam, the gamma test pass rate was greater than 98% for the 3%/3mm/10% criterion. Conclusion: We have determined key variables in our RW model for proton dose calculation. Compared with commercial pencil beam algorithms, our RW model much improves the dose accuracy in heterogeneous regions, and is about 10 times faster than MC simulations
Necessity of using heterogeneous ellipsoidal Earth model with terrain to calculate co-seismic effect
Cheng, Huihong; Zhang, Bei; Zhang, Huai; Huang, Luyuan; Qu, Wulin; Shi, Yaolin
2016-04-01
Co-seismic deformation and stress changes, which reflect the elasticity of the earth, are very important in the earthquake dynamics, and also to other issues, such as the evaluation of the seismic risk, fracture process and triggering of earthquake. Lots of scholars have researched the dislocation theory and co-seismic deformation and obtained the half-space homogeneous model, half-space stratified model, spherical stratified model, and so on. Especially, models of Okada (1992) and Wang (2003, 2006) are widely applied in the research of calculating co-seismic and post-seismic effects. However, since both semi-infinite space model and layered model do not take the role of the earth curvature or heterogeneity or topography into consideration, there are large errors in calculating the co-seismic displacement of a great earthquake in its impacted area. Meanwhile, the computational methods of calculating the co-seismic strain and stress are different between spherical model and plane model. Here, we adopted the finite element method which could well deal with the complex characteristics (such as anisotropy, discontinuities) of rock and different conditions. We use the mash adaptive technique to automatically encrypt the mesh at the fault and adopt the equivalent volume force replace the dislocation source, which can avoid the difficulty in handling discontinuity surface with conventional (Zhang et al., 2015). We constructed an earth model that included earth's layered structure and curvature, the upper boundary was set as a free surface and the core-mantle boundary was set under buoyancy forces. Firstly, based on the precision requirement, we take a testing model - - a strike-slip fault (the length of fault is 500km and the width is 50km, and the slippage is 10m) for example. Because of the curvature of the Earth, some errors certainly occur in plane coordinates just as previous studies (Dong et al., 2014; Sun et al., 2012). However, we also found that: 1) the co
Implications of imprecision in kinetic rate data for photochemical model calculations
Energy Technology Data Exchange (ETDEWEB)
Stewart, R W; Thompson, A M [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
1998-12-31
Evaluation of uncertainties in photochemical model calculations is of great importance to scientists performing assessment modeling. A major source of uncertainty is the measurement imprecision inherent in photochemical reaction rate data that modelers rely on. A rigorous method of evaluating the impact of data imprecision on computational uncertainty is the study of error propagation using Monte Carlo techniques. There are two problems with the current implementation of the Monte Carlo method. First, there is no satisfactory way of accounting for the variation of imprecision with temperature in 1, 2, or 3D models; second, due to its computational expense, it is impractical in 3D model studies. These difficulties are discussed. (author) 4 refs.
Implications of imprecision in kinetic rate data for photochemical model calculations
Energy Technology Data Exchange (ETDEWEB)
Stewart, R.W.; Thompson, A.M. [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
1997-12-31
Evaluation of uncertainties in photochemical model calculations is of great importance to scientists performing assessment modeling. A major source of uncertainty is the measurement imprecision inherent in photochemical reaction rate data that modelers rely on. A rigorous method of evaluating the impact of data imprecision on computational uncertainty is the study of error propagation using Monte Carlo techniques. There are two problems with the current implementation of the Monte Carlo method. First, there is no satisfactory way of accounting for the variation of imprecision with temperature in 1, 2, or 3D models; second, due to its computational expense, it is impractical in 3D model studies. These difficulties are discussed. (author) 4 refs.
Efficient Finite Element Models for Calculation of the No-load losses of the Transformer
Directory of Open Access Journals (Sweden)
Kamran Dawood
2017-10-01
Full Text Available Different transformer models are examined for the calculation of the no-load losses using finite element analysis. Two-dimensional and three-dimensional finite element analyses are used for the simulation of the transformer. Results of the finite element method are also compared with the experimental results. The Result shows that 3-dimensional provide high accuracy as compared to the 2 dimensional full and half model. However, the 2-dimensional half model is the less time-consuming method as compared to the 3 and 2-dimensional full model. Simulation time duration taken by the different models of the transformer is also compared. The difference between the 3-dimensional finite element method and experimental results are less than 3%. These numerical methods can help transformer designers to minimize the development of the prototype transformers.
Isotope-hydrological models and calculational methods for investigation of groundwater flow
International Nuclear Information System (INIS)
Marton, L.
1982-01-01
Recharge of groundwater through a semi-confining bed is a typical hydrogeological phenomenon in quaternary deposits which are elevated to a lesser or greater degree above the surroundings. A simple hydrological model has been introduced in which the aquifer is recharged only by precipitation through a semi-permeable layer. For applying the model, it is necessary to know the age of the water or the radioisotope concentrations in some sections of the ground-water flow system. On the basis of the age, the hydraulic conductivity of the aquifer and of the semiconfining bed and the steady rate of infiltration can be calculated. Other hydraulic parameters can be determined with the help of a mathemathical model worked out by Freeze and Witherspoon. The hydrological and mathemathical models are inversely used and are complementary. The reliability and applicability of the hydrological model has been proved in practice and good results were gained in hydrogeological research carried out in Hungary. (author)
Extended wave-packet model to calculate energy-loss moments of protons in matter
Archubi, C. D.; Arista, N. R.
2017-12-01
In this work we introduce modifications to the wave-packet method proposed by Kaneko to calculate the energy-loss moments of a projectile traversing a target which is represented in terms of Gaussian functions for the momentum distributions of electrons in the atomic shells. These modifications are introduced using the Levine and Louie technique to take into account the energy gaps corresponding to the different atomic levels of the target. We use the extended wave-packet model to evaluate the stopping power, the energy straggling, the inverse mean free path, and the ionization cross sections for protons in several targets, obtaining good agreements for all these quantities on an extensive energy range that covers low-, intermediate-, and high-energy regions. The extended wave-packet model proposed here provides a method to calculate in a very straightforward way all the significant terms of the inelastic interaction of light ions with any element of the periodic table.
Comparison of inverse dynamics calculated by two- and three-dimensional models during walking
DEFF Research Database (Denmark)
Alkjaer, T; Simonsen, E B; Dyhre-Poulsen, P
2001-01-01
recorded the subjects as they walked across two force plates. The subjects were invited to approach a walking speed of 4.5 km/h. The ankle, knee and hip joint moments in the sagittal plane were calculated by 2D and 3D inverse dynamics analysis and compared. Despite the uniform walking speed (4.53 km....../h) and similar footwear, relatively large inter-individual variations were found in the joint moment patterns during the stance phase. The differences between individuals were present in both the 2D and 3D analysis. For the entire sample of subjects the overall time course pattern of the ankle, knee and hip...... the magnitude of the joint moments calculated by 2D and 3D inverse dynamics but the inter-individual variation was not affected by the different models. The simpler 2D model seems therefore appropriate for human gait analysis. However, comparisons of gait data from different studies are problematic...
Directory of Open Access Journals (Sweden)
B. Jenkins
1997-06-01
Full Text Available Calculations using the Sheffield University plasmasphere ionosphere model have shown that under certain conditions an additional layer can form in the low latitude topside ionosphere. This layer (the F3 layer has subsequently been observed in ionograms recorded at Fortaleza in Brazil. It has not been observed in ionograms recorded at the neighbouring station São Luis. Model calculations have shown that the F3 layer is most likely to form in summer at Fortaleza due to a combination of the neutral wind and the E×B drift acting to raise the plasma. At the location of São Luis, almost on the geomagnetic equator, the neutral wind has a smaller vertical component so the F3 layer does not form.
Reply to comment on 'Model calculation of the scanned field enhancement factor of CNTs'
International Nuclear Information System (INIS)
Ahmad, Amir; Tripathi, V K
2010-01-01
In the paper (Ahmad and Tripathi 2006 Nanotechnology 17 3798), we derived an expression to compute the field enhancement factor of CNTs under any positional distribution of CNTs by using the model of a floating sphere between parallel anode and cathode plates. Using this expression we can compute the field enhancement factor of a CNT in a cluster (non-uniformly distributed CNTs). This expression was used to compute the field enhancement factor of a CNT in an array (uniformly distributed CNTs). We used an approximation to calculate the field enhancement factor. Hence, our expressions are correct in that assumption only. Zhbanov et al (2010 Nanotechnology 21 358001) suggest a correction that can calculate the field enhancement factor without using the approximation. Hence, this correction can improve the applicability of this model. (reply)