bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Gene Therapy for Hemoglobin Disorders
Authors: NIENHUIS ARTHUR W. , HANAWA HIDEKI , SAWAI NOBUKUNI , SORRENTINO BRIAN P. , PERSONS DEREK A.
Published: March 2009

Abstract: The hemoglobin disorders, severe β‐thalassemia and sickle cell anemia, are prevalent monogenetic disorders which cause severe morbidity and mortality worldwide. Gene therapy approaches to these disorders envision stem cell targeted gene transfer, autologous transplantation of gene‐corrected stem cells, and functional, phenotypically corrective globin gene expression in developing erythroid cells. Lentiviral vector systems potentially appear to afford adequately efficient gene transfer into stem cells and are capable, with appropriate genetic engineering, of transferring a globin gene with the regulatory elements required to achieve high‐level, erythroid‐specific expression. Herein are results obtained in use of lentiviral vectors to insert a γ‐globin gene into murine stem cells with phenotypic correction of the thalassemia phenotype. Further, we have developed a drug‐selection system for genetically modified stem cells based on a mutant form of methylguanine, methyltransferase, which allows selective amplification of genetically modified stem cells with phenotypic correction even in the absence of myeloablation prior to stem cell transplantation. These advances provide essential preclinical data which build toward the development of effective gene therapy for the severe hemoglobin disorders.
Biology and Plasticity of CD133+ Hematopoietic Stem Cells
Authors: HANDGRETINGER RUPERT , GORDON PAUL R. , LEIMIG THASIA , CHEN XIAOHUA , BÜHRING HANS‐JÖRG , NIETHAMMER DIETRICH , KUÇI SELIM
Published: March 2009

Abstract: AC133 (CD133) is a highly conserved antigen expressed on hematopoietic stem cells with unknown function. In order to further characterize CD133+ progenitor cells, we purified CD133+ stem cells using the method of magnetic activated cell sorting (MACS) from healthy adult volunteers mobilized with granulocyte colony‐stimulating growth factor (G‐CSF) to a mean purity of 94%. The purified CD133+ cells highly engrafted NOD/SCID mice. In addition, unseparated mononuclear cells or CD133+ stem cells isolated from the bone marrow of transplanted NOD/SCID mice gave rise to engraftment of secondary recipients. Upon ex vivo culture of purified CD133+ cells with FLT3/Flk2 ligand (FL) and interleukin‐6 (IL‐6), a plastic‐adherent cell population could be observed after 6 weeks in culture. These adherent cells did not express CD34 or CD133 antigens on their surface, nor did they express markers for endothelial, mesenchymal, or dendritic cells. After incubation of these adherent cells with stem cell factor (SCF), non‐adherent cells were observed which partially co‐expressed CD133, but were negative for CD34. These nonadherent CD34− cells showed a high engraftment capacity in NOD/SCID mice. From our results, we conclude that CD133 might be a marker of early progenitors with a high NOD/SCID engraftment potential. The fact that CD133+ hematopoietic progenitors can give rise to an adherent population which is CD133− and CD34− and that these cells can again give rise to a CD133+CD34− stem cell population with high NOD/SCID engraftment potential indicates the plasticity of hematopoietic precursors. CD133+ stem cells might be useful for research and for clinical application.
CDCP1 Is a Novel Marker for Hematopoietic Stem Cells
Authors: CONZE TIM , LAMMERS REINER , KUÇI SELIM , SCHERL‐MOSTAGEER MARWA , SCHWEIFER NORBERT , KANZ LOTHAR , BÜHRING HANS‐JÖRG
Published: March 2009

Abstract: CDCP1 is a transmembrane protein that contains three CUB domains within the extracellular region and a hexalysine stretch within the cytoplasmic region. CDCP1 mRNA is highly expressed in lung and colon tumors and in the erythroleukemic cell line K562. To analyze CDCP1 protein expression, monoclonal antibodies against the extracellular domain of CDCP1 were raised. For this purpose, CDCP1 was overexpressed in NIH‐3T3 cells. Balb/c mice were then immunized with the resultant cell line NIH‐3T3/huCDCP1. After fusion of SP2/0 cells with immune spleen cells, hybridoma clones were selected that secreted antibodies reacting with NIH‐3T3/huCDCP1 cells but not with parental cells. Four antibodies (CUB1‐CUB4) were obtained that fulfilled these criteria. Screening of peripheral blood cells revealed that the antibodies did not recognize mature lymphocytes, monocytes, granulocytes, erythrocytes, or platelets. In contrast, multi‐color analyses revealed that CDCP1 protein is almost exclusively expressed on a subset of CD34+ stem/progenitor cells in bone marrow. Transplantation of purified CDCP1+ cells into NOD/SCID mice resulted in engraftment of human cells with multi‐lineage differentiation potential, suggesting that CDCP1 is a novel marker for hematopoietic stem cells.
Isolation and characterization of microsatellite markers from Teretrius nigrescens Lewis (Coleoptera: Histeridae), predator of the storage pest Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)
Authors: OMONDI A. B. , ORANTES L. C. , VAN DEN BERG J. , MASIGA D. , SCHULTHESS F.
Published: March 2009

Teretrius nigrescens is a predator of the larger grain borer (LGB) Prostephanus truncatus, an invasive post‐harvest pest in Africa. We describe the isolation and characterization of 24 novel polymorphic microsatellite markers and their testing on a population from Honduras. Alleles per locus ranged between 2 and 12, and observed heterozygosity between 0.037 and 0.646. Six loci deviated significantly from Hardy–Weinberg equilibrium and showed evidence of null alleles. These markers will be useful for studies of the predator's population structure and characterizing populations for control of LGB.
Novel polymorphic microsatellite loci for the protogynous hermaphrodite slinger sea bream (Chrysoblephus puniceus, Sparidae)
Authors: CHOPELET JULIEN , HELYAR SARAH , MANN BRUCE , MARIANI STEFANO
Published: March 2009

As a result of the global decline of fish stocks, an increasing number of fish species are becoming targets of heavy exploitation, often concomitantly with a lack of biological knowledge on their structure and demographics. Here we present 11 new polymorphic microsatellite loci, isolated from the slinger sea bream (Chrysoblephus puniceus, Sparidae), a relatively recent target of coastal fisheries in eastern South Africa. Levels of genetic diversity were assessed in 39 individuals collected from the KwaZulu‐Natal coast (Park Rynie, South Africa). Observed and expected heterozygosities varied between 0.39 and 0.97 and between 0.53 and 0.96, respectively. One locus (SL35) showed significant heterozygote deficiency and linkage disequilibrium was detected between SL35 and SL1. Importantly, five of these microsatellites cross‐amplify in Cheimerius nufar, a sympatric species also subjected to exploitation.
Polygonum istanbulicum Keskin sp. nov. (Polygonaceae) from Turkey
Authors: Keskin Mustafa
Published: March 2009

A new Polygonum L. species, P. istanbulicum Keskin, is described from the İstanbul province of Turkey and is compared with other allied species. In addition, an updated list of all Polygonum (s. l.) species recorded from Turkey is provided.
Lectotypifications and notes on the application of names of Hieracium sect. Hieracium, sect. Bifida and sect. Vulgata (Asteraceae) based on material from the province of Dalarna, central Sweden
Authors: Tyler Torbjörn
Published: March 2009

Lectotypes are designated for 174 names of taxa described based on material from the Swedish province of Dalarna and accepted to belong to Hieracium sect. Hieracium, sect. Bifida and sect. Vulgata. The taxonomic and nomenclatural implications, i.e. taxonomic synonyms and infraspecific taxa not worthy of taxonomic recognition, of the lectotypifications are discussed. Three new combinations, H. mundulifolium (Johanss.) T. Tyler, H. oligasterum (Johanss. & Sam.) T. Tyler and H. transtrandense T. Tyler, are proposed to accommodate the infraspecific taxa H. gilvocaniceps Johanss. var. mundulifolium Johanss., H. expallidiforme (Dahlst. ex. Stenstr.) Dahlst. var. oligasterum Johanss. & Sam. and H. insuccatum Johanss. var. occidentale Johanss. & Sam. respectively, when treated at the rank of species.
Iranian Registry of Clinical Trials: path and challenges from conception to a World Health Organization primary register
Authors: Solaymani‐Dodaran Masoud , Ostovar Afshin , Khalili Davood , Vasei Muhammad
Published: March 2009

Objective Following the reforms in 1985 in which medical education was integrated into the National Health Service, we have witnessed an increase in teaching, training, and research capacity, improvement in quality of services, and a major boost in medical research in Iran. Following the surge in research activity, the need for public registration of clinical trials was raised within academic circles, particularly after the initiative by the International Committee of Medical Journal Editors in 2004.

Method In line with this global movement, the Iranian Registry of Clinical Trials was developed by a team of Iranian researchers with support from the Ministry of Health and Medical Education.

Results In our experience, the challenges for developing a national registry for clinical trials are: (i) choosing a committed, versatile leader with the skills and expertise to work and communicate with a variety of stakeholders and other people involved in the process; (ii) securing the necessary resources and political support to minimize resistance and act as a positive force for implementing changes; (iii) developing strong liaison between the information technology team and website administrators to develop a highly functioning website; and (iv) developing the culture of transparency within society in general, and the research community in particular, which goes far beyond setting up a registry.

Conclusion The Iranian Registry of Clinical Trials has made a good start, and should fulfill its mission of providing an accessible source of information for the general public and researchers. This is the goal we have set ourselves.
Strategies for Promoting the Development of Evidence‐Based Medicine in China
Authors: Li Youping , Wu Taixiang , Shang Hongcai , Yang Kehu ,   on behalf of all subcentres attending the Chinese EBM Working Meeting in December 2008
Published: March 2009

Background Some important events have happened in clinical medicine outside China in recent years changing the field.

Event A working meeting of the EBM network was held to promote the development of EBM in China. The delegates came from 15 EBM centres in universities or hospitals and some strategies and measures were discussed in the meeting.

Results 1. Enhancing the transparency of clinical trials including clinical trial registration, standardization of reporting results, transparent clinical process, and establishing a reliable inner quality control system; 2. Promoting the modernization of traditional Chinese medicine including initiating the Chinese Network of Complementary and Alternative Medicine (CNCAM), developing the Good Practices of TCM clinical guidelines and clinical pathways, and developing a grading system for TCM evidence; 3. Developing an independent entity of clinical research, training on methodology of clinical studies and conducting cooperative clinical trials to strengthen the capability of clinical study of the members of EBM network.

Conclusion Transparency of clinical trials and the capability of clinical studies are the most important needs in the healthcare field both in the world and China. A consensus about developing EBM in China has been made among the participants of the Chinese EBM Working Meeting in December 2008.
Haptic Wrists: An Alternative Design Strategy Based on User Perception
Authors: Martín Javier , Savall Joan , Díaz Iñaki , Hernantes Josune , Borro Diego
Published: March 2009

A new three degree-of-freedom (3DOF) torque feedback wrist is being developed to be added to an existing 3DOF force feedback haptic device. It is difficult to find a satisfactory solution to the mechanical design problem, mainly because of the required large rotational workspace and severe weight constraints. This work proposes an alternative design strategy based on user perception, which allows simplification of the mechanics. The proposed approach consists of substituting the last rotational DOF of the wrist with a pseudohaptic DOF. Thanks to specially designed visuotactile cues, the pseudohaptic DOF is integrated with the active DOF into the same device, being able to generate free motion and collision detection perception to the user. This approach provides for simpler kinematics, lightweight designs, lower inertias, and less friction, which are key advantages for the inclusion of torque feedback into force feedback devices.
Sensor Augmented Virtual Reality Based Teleoperation Using Mixed Autonomy
Authors: Kadavasal Muthukkumar S. , Oliver James H.
Published: March 2009

A multimodal teleoperation interface is introduced, featuring an integrated virtual reality (VR) based simulation augmented by sensors and image processing capabilities onboard the remotely operated vehicle. The proposed virtual reality interface fuses an existing VR model with live video feed and prediction states, thereby creating a multimodal control interface. VR addresses the typical limitations of video based teleoperation caused by signal lag and limited field of view, allowing the operator to navigate in a continuous fashion. The vehicle incorporates an onboard computer and a stereo vision system to facilitate obstacle detection. A vehicle adaptation system with a priori risk maps and a real-state tracking system enable temporary autonomous operation of the vehicle for local navigation around obstacles and automatic re-establishment of the vehicle’s teleoperated state. The system provides real time update of the virtual environment based on anomalies encountered by the vehicle. The VR based multimodal teleoperation interface is expected to be more adaptable and intuitive when compared with other interfaces.
A Computer Program Predicting Steady-State Performance of a Nuclear Research Reactor’s Cooling System
Authors: Sidi Ali Kamel
Published: March 2009

The performances of a nuclear reactor are directly affected by its cooling system, especially when it uses wet towers to evacuate the heat generated in the nuclear reactor core. Failure of the cooling system can yield very serious damages to most of the components of the nuclear reactor core. In this work, a computer program simulating the thermal behavior of a nuclear research reactor’s cooling system is presented. Starting from the proposed start-up data of the reactor, the program predicts the cooling capacity of the nuclear reactor while taking into account the current climate conditions and also monitors the behavior of the thermal equipments involved in this process and this for different levels of power. The proposed simulation is based on a set of heat transfer equations representing all the equipments making up the cooling system up to the nuclear reactor core. Owing to the proposed inter-connected set of equations used to predict the thermal behaviour of the system, this program allows the user to modify at will a specified parameter and study the induced resulting effects on the rest of the system. The computer program developed has been experimentally validated on an operational system generating 6.8 MW and the obtained results are in good agreement with experiment. The results produced by the program concern the capacity of the cooling system to evacuate all the heat generated in the nuclear reactor core while taking into account the current climate conditions, the determination of the optimal number of thermal equipments that need to be engaged, the monitoring of the reactor core’s entry end exit temperatures as well as the temperatures of all the components of the cooling system. Moreover, the program gives all the characteristics of air at the exit of the cooling towers and the loss of water due to the cooling process.
Evaluation of Continuous Low-Cycle Fatigue Behaviour of High Temperature P122 Boiler Material
Authors: Pumwa John , Nam Soo Woo
Published: March 2009

The complex thermal-mechanical loading of power-generating plant components usually comprises of creep, high-cycle and low-cycle fatigue which are thermally induced by start-ups, load changes and shut-downs, producing instationary temperature gradients and hence creating strain as well as stress fields. In order to select the correct materials for these hostile environmental conditions, it is vitally important to understand the behaviour of mechanical properties of these materials. This paper reports the results of Low-cycle fatigue tests of P122 (HCM12A or 12Cr-1.8W-1.5Cu) high temperature boiler material, which is one of the latest developed materials for high temperature environments. The tests were conducted at temperatures ranging from 550°C to 700 °C at 50°C intervals with strain ranges of ±1.5 to ±3.0% at 0.5% intervals using a closed-loop hydraulic Instron material testing machine with a servo hydraulic controller. The results confirm that P122 is comparable to conventional high temperature steels. Moreover, the fracture mode assessments strongly revealed a ductile transgranular fracture mode.
Reliability of Structures During Random Loadings
Authors: Zarka Joseph , Karaouni Habib
Published: March 2009

A new framework for fatigue analysis and reliability of structures has been built which allows The analyis to be reduced to the analysis on a 2-D window with a Characterized radial cyclic loading. It is given one description for the smooth specimen and any general structure with any loading conditions; simplified analysis of inelastic structures and simple rules for damage and accumulation are taken but the results are coupled with results from returns on real structures.
Developing Predictive Maintenance Expertise to Improve Plant Equipment Reliability
Authors: Wurzbach Richard N.
Published: March 2009

On-line equipment condition monitoring is a critical component of the world-class production and safety histories of many successful nuclear plant operators. From addressing availability and operability concerns of nuclear safety-related equipment to increasing profitability through support system reliability and reduced maintenance costs, Predictive Maintenance programs have increasingly become a vital contribution to the maintenance and operation decisions of nuclear facilities. In recent years, significant advancements have been made in the quality and portability of many of the instruments being used, and software improvements have been made as well. However, the single most influential component of the success of these programs is the impact of a trained and experienced team of personnel putting this technology to work. Changes in the nature of the power generation industry brought on by competition, mergers, and acquisitions, has taken the historically stable personnel environment of power generation and created a very dynamic situation. As a result, many facilities have seen a significant turnover in personnel in key positions, including predictive maintenance personnel. It has become the challenge for many nuclear operators to maintain the consistent contribution of quality data and information from predictive maintenance that has become important in the overall equipment decision process. These challenges can be met through the implementation of quality training to predictive maintenance personnel and regular updating and re-certification of key technology holders. The use of data management tools and services aid in the sharing of information across sites within an operating company, and with experts who can contribute value-added data management and analysis. The overall effectiveness of predictive maintenance programs can be improved through the incorporation of newly developed comprehensive technology training courses. These courses address the use of key technologies such as vibration analysis, infrared thermography, and oil analysis not as singular entities, but as a toolbox resource from which to address overall equipment and plant reliability in a structured program and decision environment.
J Resistance Curve Estimation of Inhomogeneous CT Specimen
Authors: Hojo Kiminobu , Ohoto Kazutoshi , Muroya Itaru
Published: March 2009

In order to obtain the fracture toughness curve of inhomogeneous CT specimens, a simplified J-R curve estimation method has been proposed. To verify the applicability of this method, the fracture toughness test and the finite element analysis has been conducted. In overmatching case (mismatch ratio M = 2.2), the conventional ASTM standard’s J-R curve exceeded the J-R curve from the FE analysis in the plane strain condition by over 20%. On the other hand, the simplified J-R curve was located between J-R curves from the FE analyses in plane strain and plane stress condition. In undermatching case (M = 0.5), experimental J-R curves with and without the inhomogeneity effect were almost same and the conventional standard is applicable.
Distribution Parameter and Drift Velocity of Drift-Flux Model in Bubbly Flow
Authors: Hibiki Takashi , Ishii Mamoru
Published: March 2009

In view of the practical importance of the drift-flux model for two-phase flow analysis in general and in the analysis of nuclear-reactor transients and accidents in particular, the distribution parameter and the drift velocity have been studied for bubbly-flow regime. The constitutive equation that specifies the distribution parameter in the bubbly flow has been derived by taking into account the effect of the bubble size on the phase distribution, since the bubble size would govern the distribution of the void fraction. A comparison of the newly developed model with various fully-developed bubbly-flow data over a wide range of flow parameters shows a satisfactory agreement. The constitutive equation for the drift velocity developed by Ishii has been reevaluated by the drift velocity obtained from local flow parameters such as void fraction, gas velocity and liquid velocity measured under steady fully-developed bubbly flow conditions. It has been confirmed that the newly developed model of the distribution parameter and the drift velocity correlation developed by Ishii can also be applicable to developing bubbly flows.
Falling Film Evaporation in a Rectangular Channel With Different Depth
Authors: Forgione N. , Ambrosini W. , Oriolo F. , Wackers P.
Published: March 2009

This paper describes the results of experimental tests carried out to study falling film evaporation on a heated flat plate with countercurrent air flowing in a rectangular channel. Experimental tests have been run with different channel depths with respect to a previous facility configuration in order to evaluate the effect of this parameter on the measured heat and mass transfer rates. The present work is then focused on the analysis of the effect that developing flow conditions may have on the evaporation of the falling water film. Three different values of the length over the hydraulic diameter ratio of the channel have been considered: L/D = 11.83, 20.86 and 33.88. Series of dry tests with 45° inclined channel were investigated with inlet nominal velocities of 1, 2.5, 5, 7.5, 9 m/s and with nominal heated plate temperature of 70 °C and 90 °C. Corresponding wet tests were investigated with nominal film flow rate at 60 and 100 g/s, with the same nominal inlet velocities but with a temperature of the heated plate of 70 °C. The obtained results point out interesting parametric trends that provide greater insight into the considered phenomena and support the use of the heat and mass transfer analogy for predicting evaporation rates in the considered range of parameters.
A Study of Outage Management Practices at Selected U.S. Nuclear Plants
Authors: Lin James C.
Published: March 2009

This paper presents insights gained from a study of the outage management practices at a number of U.S. nuclear plants. The objective of the study was to conduct an in-depth review of the current practices of outage management at these selected plants and identify important factors that have contributed to the recent success of their outage performance. Two BWR-4, three BWR-6, and two 3-loop Westinghouse PWR plants were selected for this survey. The results of this study can be used to formulate outage improvement efforts for nuclear plants in other countries.
Application of Nuclear Energy for Seawater Desalination: Design Concepts of Nuclear Desalination Plants
Authors: Faibish R. S. , Konishi T. , Gasparini M.
Published: March 2009

Nuclear energy is playing an important role in electricity generation, producing 16% of the world’s electricity. However, most of the world’s energy consumption is in the form of heat, in which case nuclear energy could also play an important role. In particular, process heat for seawater desalination using nuclear energy has been of growing interest to some Member States of the International Atomic Energy Agency over the past two decades. This growing interest stems from increasingly acute freshwater shortages in many arid and semi-arid zones around the world. Indeed, several national and international nuclear desalination demonstration programs are already under way or being planned. Of particular interest are projects for seawater nuclear desalination plants in coastal regions, where saline feed water can serve the dual purpose of cooling water for the nuclear reactor and as feed water for the desalination plant. In principle any nuclear reactor can provide energy (low-grade heat and/or electricity), as required by desalination processes. However, there are some additional requirements to be met under specific conditions in order to introduce nuclear desalination. Technical issues include meeting more stringent safety requirements (nuclear reactors themselves and nuclear-desalination integrated complexes in particular), and performance improvement of the integrated systems. Economic competitiveness is another important factor to be considered for a broader deployment of nuclear desalination. For technical robustness and economic competitiveness a number of design variants of coupling configurations of nuclear desalination integrated plant concepts are being evaluated. This paper identifies and discusses various factors, which support the attractiveness of nuclear desalination. It further summarizes some of the key approaches recommended for nuclear desalination complex design and gives an overview of various design concepts of nuclear desalination plants, which are experienced, being implemented or evaluated by several IAEA Member States. Operating experience with nuclear desalination using a liquid-metal reactor BN-350 in Kazakhstan and several Pressurized Water Reactor units in Japan is discussed. Results of economic analyses of nuclear desalination are also presented in order to illustrate the competitiveness of this technology with other conventional desalination operations.
Design and Testing of Vacuum Breaker Check Valve for Simplified Boiling Water Reactor
Authors: Ishii M. , Xu Y. , Revankar S. T.
Published: March 2009

A new design of the vacuum breaker check valve was developed to replace the mechanical valve in a simplified boiling water reactor. Scaling and design calculations were performed to obtain the geometry of new passive hydraulic vacuum breaker check valve. In order to check the valve performance, a RELAP5 model of the simplified boiling water reactor system with the new valve was developed. The valve was implemented in an integral facility, PUMA and was tested for large break loss of coolant accident.
Criteria for Global Nuclear Energy Development
Authors: Lawrence Michael J.
Published: March 2009

Global energy consumption will at least double over the next fifty years due to population growth, increased consumption, and an urgent need to improve the standard of living in under-developed countries. Thirty percent of this growth will be for electricity. At the same time, carbon emissions must be significantly reduced to respond to concerns regarding global warming. The use of nuclear energy to meet this growing electricity demand without carbon emissions is an obvious solution to many observers, however real concerns over economics, safety, waste and proliferation must be adequately addressed. The issue is further complicated by the fact that developing countries, which have the most pressing need for additional electricity generation, have the least capability and infrastructure to deploy nuclear energy. Nevertheless, if the specific needs of developing countries are appropriately considered now as new generation reactors are being developed, and institutional arrangements based upon the fundamental principles of President Eisenhower’s 1953 Atoms For Peace speech are followed, nuclear energy could be deployed in any country. From a technical perspective, reactor safety and accessibility of special nuclear material are primary concerns. Institutionally, plant and fuel ownership and waste management issues must be addressed. International safety and safeguards authority are prerequisites. While the IAEA’s IMPRO program and the United States’ Generation IV programs are focusing on technical solutions, institutional issues, particularly with regard to deployment in developing countries, are not receiving corresponding attention. Full-service, cradle-to-grave, nuclear electricity companies that retain custody and responsibility for the plant and materials, including waste, are one possible solution. Small modular reactors such as the Pebble Bed Modular Reactor could be ideal for such an arrangement. While waste disposal remains a major obstacle, this is already true for numerous nuclear programs even in developed countries with limited geologically suitable formations. Fortunately, several organizations are currently pursuing international solutions to the nuclear waste disposal problem. While the capability to deploy nuclear energy in a specific country may not be desirable for a number of reasons, we should not develop nuclear hardware that can only benefit and serve technically and economically advanced countries. The potential benefits of nuclear energy are global, and we should not unduly limit that potential by inattention today to the requirements necessary for global deployment.
Emersion Testing of Phe´nix Reactor Components From Liquid Sodium
Authors: Baque´ F. , Martin L.
Published: March 2009

The life extension of the Phe´nix LMFR involved the inspection of reactor vessel internal structures : among other techniques, a visual inspection was performed of the above core structure, fuel assembly heads and upper components. To make this inspection possible, a partial draining of the main vessel from primary liquid sodium was carried out (sodium at 180°C and argon cover at 150°C). The test program aimed at obtaining further knowledge on the process of wetting of sodium — as pure metal — on Phe´nix Plant assembly heads — made of stainless steel —, as well as on the internal structure weldings, was carried out from November 1998 to January 1999. The main results were as follows: • the sodium meniscus measured during sodium lowering against the non-wet vertical structures reaches 10 mm in height. On wetted structures, it reaches only 5.3 mm. • when sodium level decreases, the process if very regular. However, re-flooding is carried out in stages. • a difference of 0.2 mm between two heads altitudes is enough to observe successively each of the heads. • the quality of sodium does not modify the wetting process (in the range of cold trap temperature : 110–140°C). • the influence of lighting is important. • the visibility limit of emerging electro-eroded cracks (from 0.17 to 1.0 mm) is at 0.20 mm. • the visibility of a horizontal welding, machined or not, is good when the lighting is sufficient. • the superficial flow of sodium only modifies the wetting process for the closest heads. A final test allowed to observe that the global inclination of the assembly head mock-up does not modify the wetting process. These experimental results were part of the feasibility demonstration of the visual inspection within the actual Phe´nix Plant that was undertaken in 2001.
Engineered Barriers in the Waste Isolation Pilot Plant
Authors: Ghose Shankar
Published: March 2009

The Waste Isolation Pilot Plant (WIPP) is a deep geological repository being developed by the Department of Energy as a research and disposal facility in the bedded salt deposit of New Mexico. WIPP is essentially an underground salt mine at 2150 feet (655 meters) below the surface and operates on multiple barrier mechanism. Engineered barriers provide an additional protective measure to prevent the movement of fluid towards the accessible environment. Four types of engineered barriers are used in the WIPP disposal system. This paper presents an analysis of the effectiveness of the engineered barriers in various repository environments.
Flow Regime Identification of Co-Current Downward Two-Phase Flow With Neural Network Approach
Authors: Goda Hiroshi , Kim Seungjin , Mi Ye , Finch Joshua P. , Ishii Mamoru , Uhle Jennifer
Published: March 2009

Flow regime identification for an adiabatic vertical co-current downward air-water two-phase flow in the 25.4 mm ID and the 50.8 mm ID round tubes was performed by employing an impedance void meter coupled with the neural network classification approach. This approach minimizes the subjective judgment in determining the flow regimes. The signals obtained by an impedance void meter were applied to train the self-organizing neural network to categorize these impedance signals into a certain number of groups. The characteristic parameters set into the neural network classification included the mean, standard deviation and skewness of impedance signals in the present experiment. The classification categories adopted in the present investigation were four widely accepted flow regimes, viz. bubbly, slug, churn-turbulent, and annular flows. These four flow regimes were recognized based upon the conventional flow visualization approach by a high-speed motion analyzer. The resulting flow regime maps classified by the neural network were compared with the results obtained through the flow visualization method, and consequently the efficiency of the neural network classification for flow regime identification was demonstrated.
Transverse Vibrations of Single Bellows Expansion Joint Restrained Against Rotation
Authors: Kameswara Rao C. , Radhakrishna M.
Published: March 2009

The paper presents the results of investigation of transverse vibrations of single bellows expansion joint restrained against rotation on either end. A theoretical model is developed based on the Bernoulli-Euler beam theory and includes added mass of the fluid flowing inside the pipe-bellow-pipe assembly. Neglecting effects of shear and rotary inertia an exact frequency equation is derived for the transverse vibrations of single bellows expansion joint including the effects of end elastic restraints against rotation. Numerical results are presented for an example bellow showing the effects of variation of elastic restraints and internal pressure on the first four modes of vibration.
A Dynamic Performance Analysis on CANDU Fuel Handling System for Operational Improvement
Authors: Kim Jeong Mann , Jung Byung Ryul , Park Wan Kyu
Published: March 2009

The dynamic performance of the Fueling Machine (F/M) Heavy Water (D2O) supply system for Wolsong Nuclear Power Plant (NPP) was evaluated using Modular Modeling System (MMS) computer code. Parametric study has been carried out to investigate the effects of dual common set pressure and the position change rate of series valve on the dynamic behavior of common header pressure and common bleed valve position during the mode changes of supply pressure. The results show that the introduction of the series valve position demand curve and the dual common header set pressure is effective to attenuate the overshoot of common header pressure during mode changes. This does not lead any adverse effects on the system performance of supply pressure control and heavy water supply to F/M during the mode changes. The dynamic evaluation results of the F/M D2O supply system will be used for the new control system parameter settings and help to relieve system operators’ burdens during the system operation.
Load Regime Diagram of a Pipe With Cyclically Plastic Bending
Authors: Yao Yanping , Lu Ming-Wan
Published: March 2009

The criteria of piping seismic design based on linear elastic analysis has been proved to be conservative, which is mainly because the influence of plastic deformation on piping dynamic response is neglected. In the present paper, a pipe under seismic excitation is simplified as an beam with tubular cross section subjected to steady axial force and fully reversed cyclic bending moment, and the elastic-plastic behavior of the pipe is studied. Various behavior of the pipe under different combinations of axial force and cyclic bending moment is discussed and the boundary curve equations between them are obtained. Also the load regime diagram for a pipe which is formed by the boundary curve equations in the loading plane is given, from which the elastic-plastic behavior of the pipe can be determined directly.
Containment Sump Neutralization Using Trisodium Phosphate: Parametric Analysis
Authors: Zaki Tarek G.
Published: March 2009

For post-LOCA conditions, the pH of the aqueous solution collected in the containment sump after completion of injection of containment spray and ECC water, and all additives for reactivity control, fission product removal, and other purposes, should be maintained at a level sufficiently high to provide assurance that significant long-term iodine re-evolution does not occur. Long-term iodine retention may be assumed only when the equilibrium sump solution pH is above 7. This pH value should be achieved by the onset of the spray recirculation mode. A trisodium phosphate (TSP)-based, passive system can be used to achieve this pH value. This is a proven technology that is already in use in nuclear power plants. This system consists of several wire mesh baskets, filled with TSP and strategically located in the sump in order to insure timely dissolution of TSP and rapid pH rise under LOCA conditions. Accurate determination of the total quantity of TSP required to raise the pH of borated water in the sump to within the acceptable range is the key element to a proper design of this system. However, this type of analysis is quite involved and highly iterative, which requires the use of a computer program. This paper describes the basis for a computer program that determines the required quantity of TSP as a function of the quantity of borated water in the sump, the boron concentration, the sump temperature, and the specified pH value. The equilibrium quantities of boric acid species are calculated iteratively based on its molal equilibrium quotients. The equilibrium quantities of phosphoric acid species are calculated iteratively based on its dissociation constants. The charge balance error (CBE) is the sum of ionic charges for all species and ions in the solution, including sodium. All species are in equilibrium when the CBE reduces to zero. The paper also presents the results of a parametric analysis that is performed using this computer program. Ranges of borated water quantity, boron concentration, and sump temperature are considered. For these borated water quantities and sump conditions, TSP quantities required to achieve sump pH values that range from 7.0 to 8.0 are determined. The results show significant dependence on temperature. In addition, the paper provides recommendations regarding TSP basket sizing and locations within the sump, as well as pH surveillance test requirements.
Nuclear Plant Modification in a Risk-Informed Environment
Authors: Gallucci Raymond H. V.
Published: March 2009

This paper examines a specific nuclear power plant modification performed in a risk-informed regulatory environment. It quantifies both the permanent and temporary effects of the modification, and performs a cost-benefit evaluation.
Validation of a CFD Analysis Model for Predicting CANDU-6 Moderator Temperature Against SPEL Experiments
Authors: Yoon Churl , Rhee Bo Wook , Min Byung-Joo
Published: March 2009

A validation of a 3D CFD model for predicting local subcooling of the moderator in the vicinity of calandria tubes in a CANDU-6 reactor is performed. The small scale moderator experiments performed at Sheridan Park Experimental Laboratory (SPEL) in Ontario, Canada [1] is used for the validation. Also a comparison is made between previous CFD analyses based on 2DMOTH and PHOENICS, and the current analysis for the same SPEL experiment. For the current model, a set of grid structures for the same geometry as the experimental test section is generated and the momentum, heat and continuity equations are solved by CFX-4.3, a CFD code developed by AEA technology. The matrix of calandria tubes is simplified by the porous media approach. The standard k-ε turbulence model associated with logarithmic wall treatment and SIMPLEC algorithm on the body fitted grid are used. Buoyancy effects are accounted for by the Boussinesq approximation. For the test conditions simulated in this study, the flow pattern identified is the buoyancy-dominated flow, which is generated by the interaction between the dominant buoyancy force by heating and inertial momentum forces by the inlet jets. As a result, the current CFD moderator analysis model predicts the moderator temperature reasonably, and the maximum error against the experimental data is kept at less than 2.0°C over the whole domain. The simulated velocity field matches with the visualization of SPEL experiments quite well.
The Effect of Numerical Diffusion on Oscillatory Flow in Two-Phase Boiling Channel
Authors: Muncharoen Chaiwat , Aritomi Masanori , Sumitra Tatchai , Takemoto Takatoshi
Published: March 2009

The purpose of this paper is to study the effect of numerical diffusion on the ill-posedness and the accuracy of the model simulated the thermal-hydraulic instabilities in boiling water reactor channels. The model of the upward flow system in two-phase boiling channel simulating BWR core was developed to investigate the oscillatory flow, which was caused by flow instabilities, by using the drift-flux model. The time step was fixed at 1 millisecond at all time and the mesh size was varied as follows: 400, 200, 100, 50 and 20 mm. Then the numerical diffusion in the conservation equations was analyzed in reference to spatial mesh size. The maximums of the absolute ratios of the first order and the second order approximations of the time derivative terms (A/B) and the convective terms (C/D), including the summations of the second power of the ratios of the second order and the first order approximations of the time derivative terms (Σ(B/A)2) and the convective terms (Σ(D/C)2) were calculated to investigate the ill-posedness and the accuracy of numerical calculation of this model. The results from the model showed that the numerical diffusion in the time derivative term and the convective term play the important role in the drift-flux model for the small mesh size and may cause the ill-posedness and degrade the accuracy of the model. It was found that the A/B, the C/D, the Σ(B/A)2 and the Σ(D/C)2 in the drift-flux model highly fluctuated at the small mesh size of 50 and 20 mm. More importantly, the numerical diffusion due to the oscillation flow and the mesh size variation may have an effect on the amplitude of the pressure drop of the oscillatory flow at the small mesh size.
EDF’s Engineering Experience and Contribution to the Nuclear Development
Authors: Salha Bernard , Fourest Bernard , Arpino Jean-Marc
Published: March 2009

Electricite´ de France (EDF) is now operating 58 nuclear power units which produce 76% of the electri-city generated in France. This EDF’s industrial success is the result of its capacity to master and optimize its production tool, from design through operation. EDF’s integrated engineering is in the heart of this process of technical expertise and economic optimization. It allows to be in interface between the needs of operators and industrials suppliers, while accumulating a significant feedback of operating experience. The will of achieving the process of frenchifying PWR technology and to implement new industrial innovations have ended up in the new NPP of 100% french design, the N4 series and its significant innovations. EDF energy policy is to keep the nuclear option open for the future. This strategy results from the need to improve the availability and the life extension of the units in operation and to prepare the remplacement of the operating reactors around 2015. This is the objective of the European Pressurized Reactor (EPR), a French-German joint project. EDF is also applying this industrial process in its international projects. For example China, which desires to implement a standardized nuclear program and to move foward the complete autonomy of its nuclear industry, has decided to adopt a similar approach to EDF’s one.
Operational Events Noted for Power Uprated Plants and Potential Safety Implications
Authors: Cronenberg A. W. , Powers D. A. , Savio R. P.
Published: March 2009

During the past several decades the US Nuclear Regulatory Commission (NRC) has reviewed and approved in excess of 50 licensee requests for power uprates, most of which have been in the range of 1–6% increase. More recently the agency has received License Amendment Requests (LARs) for significant power increases, in the range of 15–20%, which are under current review. Although each uprate request is evaluated to assure that current regulatory requirements are satisfied, concerns have developed regarding the safety implications of power uprates of this magnitude for the aging population of US-LWR plants. Such concerns stem from operational events noted for plants having received power uprates, including failure to fully-insert control rods in high-power/high-burnup PWR fuel assemblies, piping failures, and reactivity anomalies. Of particular concern is the potential for synergistic/compounding effects, for example higher core power when combined with system/component degradation via plant aging for plant license renewal, or higher power in conjunction with fuel life extensions to elevated burnup. This paper examines a number of operational events for uprated plants and potential safety implications of such events.
A Digital Photographic Study on Nucleate Boiling in Subcooled Flow for Water and Refrigerant 134a Fluids
Authors: Bang In Cheol , Baek Won-Pil , Chang Soon Heung
Published: March 2009

The behavior of near-wall bubbles in subcooled flow boiling has been investigated photographically for water flow in vertical, one-side heated and rectangular channels at mass fluxes of 500, 1500, 2000 kg/m2s under atmospheric pressure and for R134a in channels of the same kind at mass fluxes of 1000, 2000 kg/m2s under 7 bar. Digital photographic techniques are used for the visualization, which are rapidly advanced in recent. Primary attention is given to the bubble coalescence phenomenon and the structure of the near-wall bubble layer. At subcooled and low-quality conditions of both fluids, discrete attached bubbles, sliding bubbles, small coalesced bubbles and large coalesced bubbles or vapor clots are observed on the heated surface as the heat flux is increased from a low value. Particularly for R134a, vapor remnants below discrete bubble on the heating surface are observed. Nucleation site density increases with the increases in heat flux and channel-averaged enthalpy, while discrete bubbles coalesce and form large bubbles, resulting in large vapor clots. Waves formed on the surface of the vapor clots are closely related to Helmholtz instability. At sufficiently high heat fluxes, three characteristic layers were observed in the heated channel: (a) a superheated liquid layer with small bubbles attached on the heated wall, (b) a flowing bubble layer consisting of large coalesced bubbles over the superheated liquid layer, and (c) the liquid core over the flowing bubble layer.