scholarly journals The Modeling of Laboratory Experiments with COMSOL Multiphysics Using Simplified Hydromechanical Model

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 754
Author(s):  
Asta Narkuniene ◽  
Povilas Poskas ◽  
Darius Justinavicius
Keyword(s):  
Large Scale ◽  
Spent Nuclear Fuel ◽  
Coupled Processes ◽  
Research Centre ◽  
Comsol Multiphysics ◽  
Elastic Model ◽  
Linear Elastic ◽  
Mechanical Evolution ◽  
Energy Environment ◽  
High Level

Coupled physical processes will take place in a multibarrier disposal system for spent nuclear fuel and high-level radioactive waste. The knowledge of these processes (thermal, hydraulic, mechanical, chemical, microbiological, etc.) as well as the scope and scale of their interactions is fundamental for the safety assessment of a disposal facility. Numerical modeling is an important component in the process of acquiring and deepening the knowledge of coupled processes, while experimental evidence isimportant for model validation. This article will present a hydro-mechanical model developed by the Lithuanian Energy Institute (LEI) in the framework of H2020 project BEACON (Bentonite Mechanical Evolution). The non-linear elastic model developed in COMSOL Multiphysics (Burlington, MA 01803, USA) was applied to predict the swelling behavior of large-scale oedometer experiments (MGR) performed by Research Centre for Energy, Environment and Technology (CIEMAT,Spain). In these experiments on bentonite hydration at isochoric conditions, a sample was made of two layers of calcium bentonite (FEBEX type) having initially different hydro-mechanical characteristics: one layer made of pellets and the other of a compacted block. Satisfactory agreement between the modeling results and the experimental data were obtained, especially for water intake and sample saturation.

Shipment of Spent Nuclear Fuel From the Czech Republic for Reprocessing

2014 ◽  
Author(s):  
Josef Podlaha
Keyword(s):  
Czech Republic ◽  
Nuclear Fuel ◽  
Research Reactor ◽  
Spent Nuclear Fuel ◽  
Research Centre ◽  
Packaging System ◽  
The Czech Republic ◽  
The Us ◽  
Global Threat ◽  
High Level

After more than 50 years of operation of the research reactor operated by ÚJV Řež, a. s. (ÚJV) or the Research Centre Řež, as the case may be, a large amount of spent nuclear fuel (SNF) of Russian origin has accumulated. In 2005, ÚJV joined the Russian Research Reactor Fuel Return (RRRFR) program under the US-Russian Global Threat Reduction Initiative (GTRI) and started the process of SNF shipment from the LVR-15 research reactor back to the Russian Federation (RF) using the ŠKODA VPVR/M transport packaging system (TPS). Two SNF shipments from ÚJV were carried out in 2007 and 2013. After the shipments were completed, only low-enriched nuclear fuel with a maximum enrichment below 20% of 235U remained on the territory of the Czech Republic. ÚJV also participates in shipments of SNF from other countries. The services of ÚJV comprise mainly ŠKODA VPVR/M TPS leasing, technical oversight and expertise during cask handling, SNF loading and cask closing and sealing. Up to now, ÚJV has participated in thirteen shipments of SNF from eight countries; one shipment is currently being prepared. High-level radioactive waste (HLW) will be generated from SNF reprocessing. The vitrified HLW will be returned to the Czech Republic as stated in the Russian-Czech Intergovernmental Agreement on Co-operation in Nuclear Energy. The return of the waste represents very complex and complicated work, technically, legally and contractually.

An Overview of Risk Management Planning for Hot-Isostatic Pressure Treatment of High-Level Waste Calcine for the Idaho Cleanup Project

2012 ◽  
Author(s):  
Brian D. Preussner ◽  
Joseph A. Nenni ◽  
Vondell J. Balls
Keyword(s):  
Risk Management ◽  
Systems Engineering ◽  
Large Scale ◽  
Spent Nuclear Fuel ◽  
Waste Form ◽  
High Level Waste ◽  
Simultaneous Application ◽  
Time And Motion ◽  
High Level ◽  
Hip Process

The Calcine Disposition Project (CDP) of the Idaho Cleanup Project (ICP) has the responsibility to retrieve, treat, and dispose of the calcine stored at the Idaho Nuclear Technology and Engineering Center (INTEC) located at the Idaho National Laboratory. Calcine is the granular product of thermally treating, or calcining liquid high-level waste (HLW) that was produced at INTEC during the reprocessing of spent nuclear fuel (SNF) to recover uranium. The CDP is currently designing the Hot Isostatic Pressure (HIP) treatment for the calcine to provide monolithic, glass-ceramic waste form suitable for transport and disposition outside of Idaho by 2035 in compliance with the Idaho Settlement Agreement. The HIP process has been used by industry since its invention, by Battelle Institute, in 1955. Hot isostatic pressing can be used for upgrading castings, densifying pre-sintered components, and consolidate powders. It involves the simultaneous application of a high pressure and temperature in a specially constructed vessel. The pressure is applied on all sides with a gas (usually inert) and, so, is isostatic. The CDP will use this treatment process (10,000 psi at 1,150 C) to combine physically and chemically a mixture of calcine and granular additives into a non leachable waste-form. The HIP process for calcine involves filling a metal can with calcine and additives, heating and evacuating the can to remove volatiles, sealing the can under vacuum, and placing the can within the HIP machine for treatment. Although the HIP process has been in use for over 50 years it has not been applied in large scale radioactive service. Challenges with retrofitting such a system for Calcine treatment include 1) filling and sealing the HIP can cleanly and remotely, 2) remotely loading and unloading the HIP machine, and 3) performing maintenance and repair on a 300 ton, hydraulically actuated machine in a highly radioactive hot cell environment. In this article, a systems engineering approach, including use of industry-proven design-for-quality tools and quantitative assessment techniques is summarized. Discussions on how these techniques were used to improve high-consequence risk management and more effectively apply failure mode, RAMI, and time and motion analyses at the earliest possible stages of design are provided.

scholarly journals Modern Methods of Radiochemical Reprocessing of Spent Nuclear Fuel

2019 ◽  
pp. 52-57
Author(s):  
T. Maltseva ◽  
А. Shyshuta ◽  
S. Lukashyn
Keyword(s):  
Nuclear Fuel ◽  
Large Scale ◽  
Spent Nuclear Fuel ◽  
Fuel Cycle ◽  
Fission Products ◽  
Purex Process ◽  
Minor Actinides ◽  
Closed Fuel Cycle ◽  
Highly Active ◽  
High Level

The paper is devoted to the history of development and the current state of technological and scientific advances in radiochemical reprocessing of spent nuclear fuel from water-cooled power reactors. Regarding spent nuclear fuel (SNF) of NPP power reactors, long-term energy security involves adopting a version of its radiochemical treatment, conditioning and recirculation. Recycling SNF is required for the implementation of a closed fuel cycle and the re-use of regeneration products as energy reactor fuels. The basis of modern technological schemes for the reprocessing of the spent nuclear fuel is the “Purex” process, developed since the 60s in the USA. The classic approach to the use of U and Pu nuclides contained in spent nuclear fuel is to separate them from fission products, re-enrich regenerated uranium and use plutonium for the production of mixed-oxide (MOX) fuel with depleted uranium. The modern reprocessing plants are able to deal with fuel with further increase of its main characteristics without significant changes in the initial project. In order to close the fuel cycle, it is needed to add the following technological steps: (1) removal of high-level and long-lived components and minor actinides; (2) return of actinides to the technological cycle; (3) safe disposal of unused components. Each of these areas is under investigation now. Several new promising multi-cycle hydrometallurgical processes based on the joint extraction of trivalent lanthanides and minor actinides with their subsequent separation have been developed. A number of promising materials is suggested to be potential matrices for the immobilization of high-level components of radioactive wastes. To improve the compatibility of fuel processing with the environment, non-aqueous technologies are being developed, for instance, pyro-chemical methods for the reprocessing of various types of highly active fuels based on metals, oxides, carbides, or nitrides. An important scientific and technological task under investigation is transmutation of actinides. The results of international large-scale experiments on the partitioning and transmutation of fuel with various minor actinides and long-lived fission products confirm the real possibility and expediency of closing the nuclear fuel cycle.

Social inequality in the evolution of human societies

2019 ◽  
pp. 98-120
Author(s):  
Georgi Derluguian
Keyword(s):  
Social Inequality ◽  
Large Scale ◽  
Human Beings ◽  
Mass Violence ◽  
Public And Private ◽  
Tangible Assets ◽  
Transition To Agriculture ◽  
New Institutions ◽  
High Level ◽  
Political Economic

The author develops ideas about the origin of social inequality during the evolution of human societies and reflects on the possibilities of its overcoming. What makes human beings different from other primates is a high level of egalitarianism and altruism, which contributed to more successful adaptability of human collectives at early stages of the development of society. The transition to agriculture, coupled with substantially increasing population density, was marked by the emergence and institutionalisation of social inequality based on the inequality of tangible assets and symbolic wealth. Then, new institutions of warfare came into existence, and they were aimed at conquering and enslaving the neighbours engaged in productive labour. While exercising control over nature, people also established and strengthened their power over other people. Chiefdom as a new type of polity came into being. Elementary forms of power (political, economic and ideological) served as a basis for the formation of early states. The societies in those states were characterised by social inequality and cruelties, including slavery, mass violence and numerous victims. Nowadays, the old elementary forms of power that are inherent in personalistic chiefdom are still functioning along with modern institutions of public and private bureaucracy. This constitutes the key contradiction of our time, which is the juxtaposition of individual despotic power and public infrastructural one. However, society is evolving towards an ever more efficient combination of social initiatives with the sustainability and viability of large-scale organisations.

scholarly journals Arabidopsis Genes Essential for Seedling Viability: Isolation of Insertional Mutants and Molecular Cloning

Genetics ◽  
2001 ◽  
Vol 159 (4) ◽  
pp. 1765-1778
Author(s):  
Gregory J Budziszewski ◽  
Sharon Potter Lewis ◽  
Lyn Wegrich Glover ◽  
Jennifer Reineke ◽  
Gary Jones ◽  
...  
Keyword(s):  
Large Scale ◽  
Protein Translocation ◽  
Gene Families ◽  
Mutant Phenotype ◽  
Lethal Mutant ◽  
A Genome ◽  
Genes Encoding ◽  
High Level ◽  
Mutant Lines ◽  
Genome Scale

Abstract We have undertaken a large-scale genetic screen to identify genes with a seedling-lethal mutant phenotype. From screening ~38,000 insertional mutant lines, we identified >500 seedling-lethal mutants, completed cosegregation analysis of the insertion and the lethal phenotype for >200 mutants, molecularly characterized 54 mutants, and provided a detailed description for 22 of them. Most of the seedling-lethal mutants seem to affect chloroplast function because they display altered pigmentation and affect genes encoding proteins predicted to have chloroplast localization. Although a high level of functional redundancy in Arabidopsis might be expected because 65% of genes are members of gene families, we found that 41% of the essential genes found in this study are members of Arabidopsis gene families. In addition, we isolated several interesting classes of mutants and genes. We found three mutants in the recently discovered nonmevalonate isoprenoid biosynthetic pathway and mutants disrupting genes similar to Tic40 and tatC, which are likely to be involved in chloroplast protein translocation. Finally, we directly compared T-DNA and Ac/Ds transposon mutagenesis methods in Arabidopsis on a genome scale. In each population, we found only about one-third of the insertion mutations cosegregated with a mutant phenotype.

New Harvesting and Curing Techniques in the Production of Breeder's Seed Peanuts1

1979 ◽  
Vol 6 (2) ◽  
pp. 70-72
Author(s):  
T. A. Coffelt ◽  
F. S. Wright ◽  
J. L. Steele
Keyword(s):  
Large Scale ◽  
Combine Method ◽  
Frost Damage ◽  
New Method ◽  
Experimental Equipment ◽  
Harvesting Method ◽  
Curing Methods ◽  
Labor Requirements ◽  
High Level ◽  
Varietal Purity

Abstract A new method of harvesting and curing breeder's seed peanuts in Virginia was initiated that would 1) reduce the labor requirements, 2) maintain a high level of germination, 3) maintain varietal purity at 100%, and 4) reduce the risk of frost damage. Three possible harvesting and curing methods were studied. The traditional stack-pole method satisfied the latter 3 objectives, but not the first. The windrow-combine method satisfied the first 2 objectives, but not the last 2. The direct harvesting method satisfied all four objectives. The experimental equipment and curing procedures for direct harvesting had been developed but not tested on a large scale for seed harvesting. This method has been used in Virginia to produce breeder's seed of 3 peanut varieties (Florigiant, VA 72R and VA 61R) during five years. Compared to the stackpole method, labor requirements have been reduced, satisfactory levels of germination and varietal purity have been obtained, and the risk of frost damage has been minimized.

Results from a Large-Scale Epidemiologic Look-Back Investigation of Improperly Reprocessed Endoscopy Equipment

2012 ◽  
Vol 33 (07) ◽  
pp. 649-656 ◽  
Author(s):  
Mark Holodniy ◽  
Gina Oda ◽  
Patricia L. Schirmer ◽  
Cynthia A. Lucero ◽  
Yury E. Khudyakov ◽  
...  
Keyword(s):  
Genetic Testing ◽  
Large Scale ◽  
Bloodborne Pathogens ◽  
Medical Centers ◽  
B Virus ◽  
Immunodeficiency Virus ◽  
Viral Testing ◽  
Veterans Affairs Medical Centers ◽  
High Level ◽  
Nose And Throat

Objective.To determine whether improper high-level disinfection practices during endoscopy procedures resulted in bloodborne viral infection transmission.Design.Retrospective cohort study.Setting.Four Veterans Affairs medical centers (VAMCs).Patients.Veterans who underwent colonoscopy and laryngoscopy (ear, nose, and throat [ENT]) procedures from 2003 to 2009.Methods.Patients were identified through electronic health record searches and serotested for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Newly discovered case patients were linked to a potential source with known identical infection, whose procedure occurred no more than 1 day prior to the case patient's procedure. Viral genetic testing was performed for case/proximate pairs to determine relatedness.Results.Of 10,737 veterans who underwent endoscopy at 4 VAMCs, 9,879 patients agreed to viral testing. Of these, 90 patients were newly diagnosed with 1 or more viral bloodborne pathogens (BBPs). There were no case/proximate pairings found for patients with either HIV or HBV; 24 HCV case/proximate pairings were found, of which 7 case patients and 8 proximate patients had sufficient viral load for further genetic testing. Only 2 of these cases, both of whom underwent laryngoscopy, and their 4 proximates agreed to further testing. None of the 4 remaining proximate patients who underwent colonoscopy agreed to further testing. Mean genetic distance between the 2 case patients and 4 proximate patients ranged from 13.5% to 19.1%.Conclusions.Our investigation revealed that exposure to improperly reprocessed ENT endoscopes did not result in viral transmission in those patients who had viral genetic analysis performed. Any potential transmission of BBPs from colonoscopy remains unknown.

scholarly journals Revealing the constituents of Egypt’s oldest beer using infrared and mass spectrometry

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mohamed A. Farag ◽  
Moamen M. Elmassry ◽  
Masahiro Baba ◽  
Renée Friedman
Keyword(s):  
Large Scale ◽  
Beer Brewing ◽  
Chemical Signatures ◽  
Chemical Determination ◽  
Materials Used ◽  
High Level ◽  
Beer Production ◽  
First Time ◽  
Detailed Chemical

Abstract Previous studies have shown that the Ancient Egyptians used malted wheat and barley as the main ingredients in beer brewing, but the chemical determination of the exact recipe is still lacking. To investigate the constituents of ancient beer, we conducted a detailed IR and GC-MS based metabolite analyses targeting volatile and non-volatile metabolites on the residues recovered from the interior of vats in what is currently the world’s oldest (c. 3600 BCE) installation for large-scale beer production located at the major pre-pharaonic political center at Hierakonpolis, Egypt. In addition to distinguishing the chemical signatures of various flavoring agents, such as dates, a significant result of our analysis is the finding, for the first time, of phosphoric acid in high level probably used as a preservative much like in modern beverages. This suggests that the early brewers had acquired the knowledge needed to efficiently produce and preserve large quantities of beer. This study provides the most detailed chemical profile of an ancient beer using modern spectrometric techniques and providing evidence for the likely starting materials used in beer brewing.

scholarly journals Equity Effects of Congestion Charges: An Exploratory Analysis with MATSim

2017 ◽  
Vol 2670 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Lucas Meyer de Freitas ◽  
Oliver Schuemperlin ◽  
Milos Balac ◽  
Francesco Ciari
Keyword(s):  
Travel Time ◽  
Large Scale ◽  
Agent Based ◽  
Promising Tool ◽  
Travel Time Savings ◽  
Time Savings ◽  
Time Changes ◽  
High Level ◽  
Congestion Charging ◽  
Equity Effects

This paper shows an application of the multiagent, activity-based transport simulation MATSim to evaluate equity effects of a congestion charging scheme. A cordon pricing scheme was set up for a scenario of the city of Zurich, Switzerland, to conduct such an analysis. Equity is one of the most important barriers toward the implementation of a congestion charging system. After the challenges posed by equity evaluations are examined, it is shown that agent-based simulations with heterogeneous values of time allow for an increased level of detail in such evaluations. Such detail is achieved through a high level of disaggregation and with a 24-h simulation period. An important difference from traditional large-scale models is the low degree of correlation between travel time savings and welfare change. While traditional equity analysis is based on travel time savings, MATSim shows that choice dimensions not included in traditional models, such as departure time changes, can also play an important role in equity effects. The analysis of the results in light of evidence from the literature shows that agent-based models are a promising tool to conduct more complete equity evaluations not only of congestion charges but also of transport policies in general.

scholarly journals A CloudSat–CALIPSO View of Cloud and Precipitation Properties across Cold Fronts over the Global Oceans

2015 ◽  
Vol 28 (17) ◽  
pp. 6743-6762 ◽  
Author(s):  
Catherine M. Naud ◽  
Derek J. Posselt ◽  
Susan C. van den Heever
Keyword(s):  
Large Scale ◽  
Cold Front ◽  
Conveyor Belt ◽  
Low Level ◽  
Scale Parameters ◽  
Convective Clouds ◽  
Cold Fronts ◽  
Surface Front ◽  
High Level ◽  
The Impact

Abstract The distribution of cloud and precipitation properties across oceanic extratropical cyclone cold fronts is examined using four years of combined CloudSat radar and CALIPSO lidar retrievals. The global annual mean cloud and precipitation distributions show that low-level clouds are ubiquitous in the postfrontal zone while higher-level cloud frequency and precipitation peak in the warm sector along the surface front. Increases in temperature and moisture within the cold front region are associated with larger high-level but lower mid-/low-level cloud frequencies and precipitation decreases in the cold sector. This behavior seems to be related to a shift from stratiform to convective clouds and precipitation. Stronger ascent in the warm conveyor belt tends to enhance cloudiness and precipitation across the cold front. A strong temperature contrast between the warm and cold sectors also encourages greater post-cold-frontal cloud occurrence. While the seasonal contrasts in environmental temperature, moisture, and ascent strength are enough to explain most of the variations in cloud and precipitation across cold fronts in both hemispheres, they do not fully explain the differences between Northern and Southern Hemisphere cold fronts. These differences are better explained when the impact of the contrast in temperature across the cold front is also considered. In addition, these large-scale parameters do not explain the relatively large frequency in springtime postfrontal precipitation.

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