bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics Simulations of a Graphite Block Under Longitudinal Impact
Authors: Kim Gyeongho , Kim DongOk , Choi Woo-Seok , Kang Ji Ho , Noh Jae Man
Published: April 2011

Graphite blocks are important core components of the high temperature gas-cooled reactor. As these blocks are simply stacked in array, collisions among neighboring components may occur during earthquakes or accidents. Thus, it is important to develop a reliable seismic model of the stacked graphite blocks and have them designed to maintain their structural integrity during the anticipated occurrences. Various aspects involved in modeling and calculating impact-contact dynamics can affect the resulting behavior of the graphite block. These include mesh size, time step, contact behavior, mechanical constraint formulation of impact-contact analysis, etc. This work is dedicated to perform comparative studies and the effects of these parameters will be identified. The insights obtained through these studies will help build a realistic impact-contact model of the graphite block, from which a lumped or reduced dynamics model will be developed for the seismic analysis of the reactor including these graphite components.
Experimental Comparisons of 3D Reconstructed Pin-Power Distributions in Full-Scale BWR Fuel Assemblies
Authors: Giust Flavio D. , Grimm Peter , Chawla Rakesh
Published: April 2011

In this paper, reconstructed local fission rates obtained with the two-group nodal diffusion program PRESTO-2, used at the Leibstadt Nuclear Power Plant (KKL) in Switzerland, are compared with experimental results and MCNPX calculations. The experimental facility consists of a test zone, where the measurements are made, surrounded by a buffer zone and two driver zones that render the system critical and also contain the control rods. The test zone consists of a tank that contains a 3×3 array of BWR fuel assemblies of type SVEA-96+. Four cases are considered, all corresponding to a 1.23 m high active zone moderated with light water at room temperature: 1) axially uniform enrichment and gadolinium content, 2) like case 1 but with a L-shaped control blade completely inserted, 3) enrichment and gadolinium content change at the core mid-plane, 4) like case 2 but with the control blade partially inserted. The comparisons give insight into the accuracy of the pin power reconstruction methodology. The axially uniform case without control blade shows a good radial agreement and a well predicted axial curvature of the flux. On the other hand, systematic deviations are observed in the radial direction for the controlled cases, with the axial heterogeneities causing deviations around the discontinuity and also in the axial curvature of the flux.
Experimental Measurement of Interfacial Parameters of Elongated Bubbles in Two Phase Gas-Liquid Flow in Horizontal and Slightly Inclined Circular Pipes
Authors: Cunha Filho J. S. , Faccini J. L. H. , Lamy C. A. , Su J.
Published: April 2011

This paper reports an experimental study of the measurement of elongated bubbles velocities and their longitudinal shapes using a high speed ultrasonic system in concurrent horizontal and at 5° and 10° inclined upward flow. The circular pipe test section is made of 25.6 mm stainless steel, followed by a transparent acrylic pipe with the same diameter. The high speed ultrasonic system consists of two transducers (10 MHz/6.35 mm diameter), a generator/multiplexer board that convert analog signals into digital data at a rate of 100 million frames per second, and a software that stores all the frames and the results of the time of flight of each signal. The results are compared with a visualization technique that consists of a high-speed digital camera recording images at rates of 125 and 250 frames per second. This range of liquid superficial velocity is from 0.2 to 1.1 m/s and that of the gas superficial velocity is from 0.35 to 1.0 m/s. The results obtained with the two experimental techniques show a good agreement among them for the elongated bubbles lengths and velocities, while having great statistics dispersion. The measured bubble shape is in agreement with literature data.
Modeling of the Effect of Parallel Rib-Type Roughness on Local, Single-Phase Heat Transfer in Rod Bundles by CFD: Part 1—Flow Resistance
Authors: Carrilho Leo , Khan Jamil
Published: April 2011

The applicability of artificial roughness in light-water reactors is investigated for the purpose of heat transfer improvement in fuel rod bundles. Since the roughening technique has a significant impact on friction losses, the investigation is divided in two distinct steps: flow resistance and convective heat transfer. The present paper deals with roughness effects on flow resistance. The technique consists of a multiplicity of small elements distributed on the surface of the simulated fuel rod. A parallel rib-type roughness is selected for this work for simplicity and since it has been extensively investigated in the past. Locally flow resistance is simulated using Computational Fluid Dynamics, CFD, in smooth and in rough rod bundles downstream of support grids with and without flow-enhancing features (vanes). This investigation is performed with basis on experimental testing. With model parameters established, various candidate roughness designs can evaluated for minimum flow resistance.
Questions Relative to CHF Testing for New Pressurized Water Reactor Advanced Fuel Assemblies
Authors: Herer Christophe
Published: April 2011

One of the limiting conditions during operation of a Pressurized Water Reactor is cladding integrity in case of occurrence of any conditions I or II events. The decoupling criterion is the absence of Departure from Nucleate Boiling (DNB) during the full sequence of any of these transients. Heat transfer between the clad and the water is limited by the DNB phenomenon when local surface heat flux is greater than the so-called Critical Heat Flux (CHF). Heat production at the surface is higher than heat removal capacity by the coolant therefore a vapor blanket is formed around the clad; consequently the heat transfer will drastically drop resulting in a sudden significant increase of the local wall temperature and clad damage may appear if no corrective action is initiated. DNB can not be estimated with physical principles only. Experimental support is needed for evaluation. Occurrence of DNB is evaluated using the Departure from Nucleate Boiling Ratio (DNBR) which is a function of both core thermal hydraulic (T/H) parameters and design of the fuel assembly. Advanced fuel assemblies claim higher CHF values compared to previous designs. Along with increased DNB performances for advanced fuel assemblies, CHF correlation development and advanced methodologies enable to extend normal operating conditions of a nuclear plant. On the one hand, CHF performances really increased allow additional margin related to the loss of fuel cladding integrity whereas on the other hand optimized correlations and advanced methodologies reduce this margin. An accurate assessment of the CHF performance of the advanced fuel assemblies is therefore required. This paper will raise issues regarding the assessment of the CHF performance of new advanced fuel assemblies design. The issues will be focused on the reliability of the experimental assessment of the CHF values and the accuracy of the transposition of mock up geometries to plant core configuration (representativity of the experiments). The verification that the tests conditions (pressure, flowrate, quality, heat flux …) ensure a proper coverage of all core conditions encountered during any of the conditions I & II transients is closely linked to DNBR methods and will not be extensively covered in this paper. This paper suggests some thoughts about relevance of the demonstration carried out by vendors on these matters.
Studies on the Correlation Between Natural Magnetization and Mechanical Damages of an Austenitic Stainless Steel
Authors: Li Hongmei , Chen Zhenmao , Zhao Tianfei
Published: April 2011

Austenitic stainless steel has been extensively used in nuclear power plants (NPP). The nondestructive Testing (NDT) of its mechanical damage at pre-crack state is very important for the safety assessment of a NPP. Aiming at to develop a new NDT method for inspecting mechanical damage before the initiation of macro cracks, the correlation between the natural magnetization and the mechanical damage is experimentally investigated for a typical austenitic stainless steel - SUS304. In the experiments, simple tensile loads were applied to lateral notch specimens to generate states of different plastic damages, and the corresponding natural magnetic field and residual strain distribution were measured after each loading cycle. The distribution of natural magnetization was analyzed based on the measured magnetic field signals in view of the principle of the metal magnetic memory phenomenon, and the dependence of the magnetization on the mechanical damage was discussed. The experimental results reveal that there is a good possibility to detect mechanical damages by measuring the natural magnetic field.
CANDU Reactor Space-Time Kinetic Modeling for Load Following Control
Authors: Xia Lingzhi , Jiang Jin
Published: April 2011

This paper presents the development of a three-dimensional space-time neutronic kinetic modeling of a CANadian Deuterium Uranium (CANDU) reactor for control system design and research, using a modal method. In this method, the reactor space-time neutron flux is synthesized by a time-weighted series of pre-calculated neutron flux modes. The modes are eigenfunctions of the governing neutron diffusion equation during reference steady-state operation. The Xenon effect has also been considered. The reactor model is then implemented within a simulation platform of CANDU6 reactor regulating system (RRS), in MATLAB/SIMULINK. Non-dimensionalized SIMULINK representation of the reactor kinetic modeling is established. Behavior of the reactor during a load following transient has been simulated using the developed reactor-modeling module. The simulation results prove the efficiency of the reactor modeling. Real-time three-dimensional neutron flux distribution during the transient analysis is represented.
Building Effective Organizations and Measures to Cope With Severe Weather in Qinshan III NPP
Authors: Zhou Jun
Published: April 2011

Severe weather such as typhoon has long been a great challenge threats the safe operation of nuclear power plants. To cope with typhoon, Qinshan III NPP has developed an effective management system, including building powerful organizations, creating standard response procedures and consumable storage, which proven to be effective to ensure the safe operation of Qinshan III plant under severe weather conditions.
Near-Term Objectives of the Works on the EUR Document
Authors: Hedin Franc¸ois , Berbey Pierre
Published: April 2011

The EUR organization was set up in the early 90’s to produce a common specification for the next LWR nuclear power plants to be built in Europe. 18 years after its foundation, the organization is well recognized and still quite active. During the last 3 years, the EUR products have mainly been evaluations of the Gen 3 LWR designs. The evaluations of the AP1000 and of the AES92 designs have been concluded in 2007 and a revised version of the evaluation of the EPR completed in 2009. Other LWR projects of potential interest for the EUR utilities, such as MHI’s APWR, are being reviewed before starting a full-scope assessment. Last, a revision C of the EUR volume 4 has been published in 2007. Coordinated actions with the other industry groups and the other stakeholders have been a centerpiece of the recent EUR strategy. In particular, the EUR and ENISS organizations have joined their efforts in nuclear safety vs. IAEA and WENRA. Also EUR and WNA/CORDEL are now working together on harmonization of the design requirements at global level. Meanwhile, the EUR organization has kept enlarging: CEZ and MVM now are active associated members and Gen-Energija from Slovenia has been invited to participate. Education and training has been dealt with actively in 2009 and 2010. The EUR organization strongly supported WNU’s “Forum on harmonization” in 2009. A more technical course about the EUR requirements is being organized in 2010 under the aegis of ENEN. Finally, a lot of preparatory material for a revision D of the EUR volumes 1 and 2 has been gathered during the last 10 years. Several options are under consideration about how to proceed towards this revision.
Development of Leak Rate Model for Helium Flow in Elliptically Converging Through Wall Crack
Authors: Zhou Sheng , Zhang Zhengming , Lamagnere Pierre , Cadiou Thierry , Berton Jean-luc , Grandotto-Biettoli Marc
Published: April 2011

Leak Before Break (LBB) analysis is widely used to demonstrate system safety of pressurized equipments in nuclear plants. Developing a precise leak rate model for helium flow in complex geometry cracks is a key point for LBB analysis in Very High Temperature gas-cooled Reactor (VHTR). A literature study was firstly carried out concentrating on leak rate models proposed or used in LBB analysis. Helium leak rate experiments named DEDIFAR have been performed using elliptically converging and diverging artificial cracks in order to study the effect of the crack length ratio of a real through wall crack. Computational Fluid Dynamics (CFD) calculations of DEDIFAR experiments are presented to analyze the distributions and tendencies of flow parameters in converging cracks. Then, a parametric study was completed to investigate crack geometry effect on mass flow rate. Based on the results of these studies, the effects of upstream pressure and convergence ratio (inside over outside crack lengths) on mass flow rate are analyzed. The results show that the pressure loss mainly concentrates around the smallest exit crack area, and that when the convergence ratio equals or exceeds 20, flow parameters inside the crack domain remain almost the same.
In-Vessel Retention of Molten Core Debris for CAP1400
Authors: Wang Junrong , Chang Huajian , Zheng Wenxiang , Zhou Zhiwei
Published: April 2011

In-vessel retention (IVR) of core melt through external reactor vessel cooling (ERVC) is a key severe accident management strategy to ensure that the vessel head remains intact and eliminate consequent major threats to containment integrity. To maintain the margin against the failure of the reactor vessel and make sure of the feasibility of IVR for its role to confine the molten corium with 1400MW power, CAP1400, Chinese version of large passive PWR, systematic investigations including experimental and analytical researches of IVR are very important to the development of CAP1400. This paper briefly reviews the progress and tasks of a four-year project which was planned to analyze, evaluate, improve and validate the effectiveness of IVR employed in the CAP1400.
CFD Analysis of Flowing Characteristics of Turbulent Flow in Rectangular Channels in Ocean Environment
Authors: Yan Binghuo , Gu Hanyang , Yang Yanhua , Huang Yanping
Published: April 2011

The flowing characteristics of turbulent flow in rectangular channels in rolling and heaving motions are investigated theoretically with FLUENT code. The flowing model of turbulent flow in rectangular channels in rolling and heaving motion is established. The effects of several turbulent models and parameters on the flow are analyzed. In rolling motion, the velocity profile in channel center is more averaged. The mixing coefficient can be strengthened significantly in rolling motion. The effect of heaving motion on turbulent flow is more limited than that of rolling motion. The turbulent kinetic energy and fluctuating velocity in rolling motion are greater than that in heaving motion and steady state. The effect of rolling motion on the turbulent flow can be depressed by the tube wall.
Transport of MOX Fuel: A Continuous Challenge
Authors: Galtier Je´roˆme
Published: April 2011

For 45 years TN International has been involved in the radioactive materials transportation field. Since the beginning the spent nuclear fuel transportation has been its core business. During all these years TN International, now part of AREVA, has been able to anticipate and fulfill the needs for new transport or storage casks designed to fit the nuclear industry evolutions. A whole fleet of casks able to transport all the materials of the nuclear fuel cycle has been developed. In this presentation we will focus on the casks used to transport the fresh and used MOX fuel. To transport the fresh MOX BWR and PWR fuel, TN International has developed two designs of casks: the MX 6 and the MX 8. These casks are and have been used to transport MOX fuel for French, German, Swiss and in a near future Japanese nuclear power plants. A complete set of baskets have been developed to optimize the loading in terms of integrated dose and also of course capacity. MOX used fuel has now its dedicated cask: the TN112 which certificate of approval has been obtained in July 2008. This cask is able to transport 12 MOX spent fuel elements with a short cooling time. The first loading of the cask has been performed in September 2008 in the EDF nuclear power plant of Saint-Laurent-des-Eaux. By its continuous involvement in the nuclear transportation field, TN International has been able to face the many challenges linked to the radioactive materials transportation especially talking of MOX fuel. TN International will also have to face the increasing demand linked to the nuclear renaissance.
Evaluation of a SGTR Accident in the Multi-Application Integrated Pressurized Water Reactor
Authors: Jiang Liguo , Peng Minjun , Liu Jiange
Published: April 2011

One of more frequent events in the Pressurized Water Reactor (PWR) is Steam Generator Tube Rupture (SGTR) accident, which is among the main accidents in the field of nuclear safety. This paper studies the SGTR event in the Multi-application Integrated Pressurized Water Reactor (IPWR) using the best-estimate thermal-hydraulic code RELAP5/MOD3.4. In the reactor of IPWR, several Once-Through Steam Generator (OTSG) cassettes are used and located between the core support and the pressure vessel. The tube rupture location is on the top of the tube sheet of a steam generator. Three different tube rupture modeling methods and several different subcooled discharge coefficients in the critical flow model are considered and compared. In the safety analysis, high pressure safety injection system, core makeup system and Passive Residual Heat Removal System (PRHRS) that would affect the accident consequences are considered.
Design Concept and Heat Transfer Analysis for a Double Pipe Channel for SCWR Type Reactors
Authors: Samuel J. , Harvel G. D. , Pioro I.
Published: April 2011

Current CANDU-type nuclear reactors use a once-through fuel channel with an annulus gas insulating it from the moderator. The current reference design for a CANDU-type SCWR is to eliminate the annulus gap and use a ceramic insert to insulate the coolant from the moderator. An alternative approach being considered is to use the annulus gap as a coolant pre-heater in a double-pipe configuration (so-called re-entrant channel). The alternative design consists of two tubes, the inner tube (flow channel) and the outer tube (pressure tube). The fuel bundles, similar to those of the current CANDU reactors, are placed in the inner tube. The inner and outer tubes form an annulus through which flows the primary coolant. The coolant will flow through the annulus receiving heat from the inner tube from one end of the channel to another. At the far end, the flow will reverse direction and enter the inner tube, and hence the fuel bundle. At the inlet, the temperature is 350°C for a high-pressure coolant (pressure of 25 MPa), which is just below the pseudocritical point. At the outlet, the temperature is about 625°C at the same pressure (the pressure drop is small and can be neglected). Channel power and flow rate are variable initial conditions. The objective of this work is to model the heat transfer in the proposed fuel channel design. The channel has been divided into several nodes for the inner tube and the annulus gap. The power in each node in the pressure tube is considered to be uniform. The numerical model calculates the temperature profiles, the heat transfer coefficients and the overall heat transfer across the double-pipe fuel channel for a given set of flow, pressure and temperature boundary conditions and the power initial conditions. With the results from the numerical model, the design of the re-entrant (double-pipe) fuel channel can be optimized to improve its efficiency.
Development of a Test Facility and Its Application for Validation and Reliability Testing of Safety-Critical Software
Authors: Zhao M. , Tailor N.
Published: April 2011

This paper describes a versatile test facility developed by AECL for validation and reliability (V&R) testing of safety-critical software used in the process trip computers for CANDU reactors. It describes the hardware and software aspects of the test facility. The test hardware consists of a test rig with a test computer used for executing the test software and a process trip computer emulator. The test software is comprised of an operating system, a test interpreter, a test oracle, and a man-machine interface. This paper also discusses the application of the test facility in V&R testing of the process trip computer, how test scripts are prepared and automatically run on the test computer, and how test results are automatically generated by the test computer, thus eliminating potential human errors. The test scripts, which contain specific instructions for testing, are text files written in a special AECL test language. An AECL Test Language Interpreter (ATLIN) program interprets the test scripts and translates structured English statements in the test scripts into test actions. The intuitive nature of the special AECL test language, the version controlled test scripts in text format and automatic test logging feature facilitate the preparation of test cases, which are easy to repeat, review and readily modifiable, and production of consistent results. This paper presents the concept of adding a process trip computer emulator for use in preparation of V&R testing. The process trip computer emulator is designed independently from the actual process trip computer but based on the same functional specification as for the process trip computer. The use of the process trip computer emulator allows the test scripts to be exercised before the actual process trip computers are available for V&R testing, thereby, resulting in a significant improvement to the project schedule. The test facility, with the built-in process trip computer emulator, is also a valuable training tool for the V&R staff and plant personnel.
Development of Integrated Treatment System to Minimize LLLW From Purex Reprocessing Plant
Authors: Suzuki Yasuhiro , Morimoto Yasutomi , Egami Hikari , Kato Takashi , Numata Mamoru , Kumazawa Mitsuaki , Balagopal Shekar
Published: April 2011

Reduction of radioactive waste volume is one of the important issues for spent fuel reprocessing plants. JGC has intensively developed radioactive waste processing technologies aiming at waste volume reduction and at immobilization with environmentally low impact for Purex type reprocessing plants. These technologies are Electrolytic Decomposition Process of Nitric Acid (E-DeP), Catalytic Decomposition Process of Nitrate Ion (C-DeP) and Electrodialytic Na Separation Process (E-SeP). An effective combination of each technology results in reduction of numbers of waste packages by one-twentieth.
DeCART Depletion Calculation for PMR200 Two-Dimensional Core
Authors: Cho Jin-Young , Jo Chang-Keun , Kim Kyo-Youn , Lee Hyun-Chul
Published: April 2011

This paper is to evaluate the depletion capability of the DeCART code for PMR200 two-dimensional core. DeCART solves the burnup equation by the matrix exponential based on the Krylov Subspace method. The depletion calculation is performed up to 270 EFPD by using total 14 burnup steps. The double heterogeneity effect is resolved by introducing the RPT method. The DeCART solutions by using a 47-G PWR neutron library are compared with the McCARD Monte Carlo solution which uses ENDF/B-VII. DeCART shows about maximum 1200 pcm eigenvalue, about maximum 2.5% block and 6.0% pin power differences near 180 EFPDs. The differences are mainly due to the library and the geometrical model discrepancy. While the reference calculation is performed by imposing the vacuum condition for the vessel outside, DeCART uses a zigzag-type boundary model. The use of the VHTR neutron library that is scheduled to develop reduces the eigenvalue differences. In the computing time, DeCART requires about 2 and half hours for 14 depletion steps. Therefore, it is concluded that the DeCART code produces a reasonable result for the VHTR core depletion calculation within an affordable computing time.
Measurement of the Dynamical Mass Transfer of a Single CO2 Bubble Using LIF/HPTS Visualization and a Photoelectric Optical Fiber Probe
Authors: Hanyu Kodai , Saito Takayuki
Published: April 2011

Gas-liquid two-phase flows are widely encountered in industrial plants such as chemical reactors, power plants, environmental plants and so on. It is essential to clarify the dissolution process of the bubbles and the structure of the gas-liquid two-phase flows for realizing the efficient operation of these industrial reactors. However, it is very difficult to clarify them because of their complexity. We made a challenge of clarifying them in detail. First, we discuss the dynamical processes of the mass transfer from a zigzagging CO2 bubble of 2.9 mm in equivalent diameter by using three measurement methods (i.e. LIF (laser induced fluorescence)/HPTS (8-hydroxypyrene-1, 3, 6-trislfonic acid), PIV and a newly developed photoelectric optical fiber probe: POFP) effectively and mutually-complementarily. We directly visualized the dynamical mass transfer process from a zigzagging CO2 bubble to the surrounding liquid by using LIF/HPTS. We measured the surrounding liquid motion induced by the bubble buoyancy using PIV. We visualized a high-CO2-concentration thin layer around the bubble was transported to the bubble rear and accumulated into the horseshoe-like vortices. The clear horse-shoe-like vortices were observed just after the launch of the bubble from a needle. Then, the wreckage of the bubble wake was transported widely into the surrounding liquid by the buoyancy driven flows. We measured directly the CO2 concentration profile inside the bubble wake by using POFP. We succeeded in clarifying the profile of the CO2 concentration inside the bubble wake, which is difficult to obtain from only the LIF/HPTS method. From this result, we obtained that the CO2 concentration takes the maximum at the center region of the bubble wake and sharply decreases toward the outer edge of the bubble wake. Second, we simultaneously measured the diameters and velocities of the bubble by using POFP. We confirmed the performance of the POFP; the results via POFP were compared with those obtained from the visualization of the bubbles by using a high-speed video camera. We demonstrated mutually-complementary use of three measurement methods is very effective to experimentally understand the dynamical processes of the mass transfer from a zigzagging CO2 bubble to the surrounding liquid.
The Study on Pyrolytic Carbon Powder in the Coating Process of Fuel Particle for High-Temperature Gas-Cooled Reactor
Authors: Liu Malin , Liu Bing , Shao Youlin
Published: April 2011

The R&D of coating process of fuel particles is one of the most important key technologies in the research work of high-temperature gas-cooled reactor (HTGR). A safe and reliable coating process is expected and related to the prospect of large-scale utilization of nuclear energy. The related research of the carbon black powder which is the main byproduct generated in the coating process is important, because it relates to the impact of coating process on the surrounding environment and is also helpful to understand the deposit mechanism of PyC (pyrolytic carbon) layer coated on the fuel particle. In the present study, the microstructure of the pyrolytic carbon powder were systematically investigated by scanning electron microscope (SEM), transmission electron microscopy (TEM), laser Raman spectroscopy and particle size analysis (PSA). It can be found that the carbon powder in the cyclone separator is composed of the nano-spherical particles with the diameter of about 50nm. The ring-layered nano-structured carbon particles could be found from the electron micrographs. The comparison between Raman spectra of carbon powder and pyrolytic carbon coated on the fuel particle showed that the droplet deposit mechanism was suitable to explain the PyC deposition process. The nano-particles agglomerate into the irregular floc and the diameters of the stable particle clusters are mainly 1 μm and 10 μm. The disposal methods of carbon black powder are also discussed.
Overview of the R&D Activities of Water Cooled Ceramic Breeder Blanket
Authors: Enoeda Mikio , Hirose Takanori , Tanigawa Hisashi , Tsuru Daigo , Yoshikawa Akira , Seki Yohji , Yokoyama Kenji , Nishi Hiroshi , Ezato Koichiro , Suzuki Satoshi
Published: April 2011

This paper overviews the R&D activity of Water Cooled Ceramic Breeder (WCCB) Blanket in Japan. Japan is performing R&D of WCCB Blanket as the primary candidate of the breeding blanket for the fusion DEMO reactor. Regarding the development of blanket module fabrication technology, a real scale First Wall (FW) was fabricated using Reduced Activation Ferritic Martensitic Steel (RAFMS) F82H. Using fabricated FW mockup, thermo-hydraulic performance and high heat flux tests were successfully performed with the heat flux equivalent to ITER TBM condition, 0.5 MW/m2, 80 cycles with the coolant condition as DEMO, 15 MPa 300 °C. Also, real scale Side Wall (SW) and real scale breeder pebble bed structure have been successfully fabricated. Furthermore, assembling of the real scale FW plate mockup and SW plate mockup was successfully performed. Development of major key technologies for the WCCB TBM structure fabrication has been progress toward the establishment of fabrication technology of WCCB TBM.
The Incorporation of Task Analysis Into AP1000 Control Rooms Design
Authors: Reed Julie , Ma Ruiqi , Li Zhonghai
Published: April 2011

The detailed design of the AP1000 power plant control rooms and human system interface (HSI) is ongoing. Task analysis (TA) is conducted and incorporated into the design of the control rooms and HSI for AP1000 to ensure that the indications and controls provided by the HSI resources enable the operator to perform the tasks required to control, monitor and maintain the AP1000 plant safely and efficiently. The major focus of the AP1000 TA is the main control room (MCR). However, TA is also conducted for the technical support center (TSC), the emergency operations facility (EOF) and maintenance, test, inspection and surveillance (MTIS) tasks. The human factors team has applied various TA methods in their analyses, including function-based task analysis (FBTA), operational sequence analysis (OSA) and hierarchical task analysis (HTA). The FBTA is based on an existing and established functional decomposition (goal-means analysis) for normal and emergency operations of the AP1000. At the top of the FBTA are two goals: 1) generate electricity and 2) prevent radiation release. These goals are decomposed to increasing levels of detail showing sub-goals or functions that satisfy the goal in the level above. The OSA is conducted for a representative set of operational and maintenance tasks. Tasks are selected to represent the full range of operating modes and the full range of activities in the AP1000 emergency response guidelines. Operator and MTIS tasks that are identified as risk-important or are associated with risk-significant systems, structures, components (SSCs) are also selected. The OSA focuses on operational requirements or task demands in terms of operator and maintainer actions or processes necessary to complete the tasks. In addition, HTA is conducted for tasks in which the data and displays available in the MCR may be utilized in the TSC and/or EOF. Four tasks were identified and analyzed in support of TSC/EOF design. The results of the HTA for the TSC/EOF are arranged by goals, tasks, and sub-tasks, and identify the information requirements to support decision making. The results of the TAs and generated recommendations are incorporated into the AP1000 HSI design as inputs at an early stage in the design process in a timely manner. The results of TAs also provide inputs to the development of procedures, staffing, training, and communication requirements.
Research and Application of Safety Information and Control System of Nuclear Power Station
Authors: Zhang Liming , Huang Weijun , Sun Yongbin , Jiang Guojin
Published: April 2011

The thesis researches the Safety Information and Control System (SICS) design principle and introduce engineering application in CPR1000 nuclear power station in China. The SICS provides sufficient control and monitoring means to bring and maintain the plant in a safe state as a backup of Main computerized Control Mean (MCM), in any plant conditions that are probable during a planed or unplanned unavailability of the MCM. The successful engineering application of SICS in different digital I&C system platform are introduced in the paper. The thesis gives the research conclusion for new general SICS of digital I&C system.
Numerical Study on Passive Control of Thermal Striping Phenomenon Using Lorentz Force in Fast Reactor
Authors: Takata Takashi , Fukuda Takeshi , Yamaguchi Akira , Uchibori Akihiro , Kimura Nobuyuki , Kamide Hideki
Published: April 2011

Liquid sodium, used as a coolant of fast reactor (FR), is an electromagnetic fluid. When a magnetic field is embedded to liquid sodium flow, the Lorentz force will be induced and flow structure such as a turbulent mixing phenomenon will be influenced. In a FR piping system, thermal fatigue is one of key issues that may occur after a piping junction of different fluid temperature. In the present paper, a numerical study of sodium flow induced by the Lorentz force on a turbulent mixing after the junction has been carried out. The large eddy simulation (LES) coupled with the electromagnetic field analysis is used for this purpose. The governing equations of the electric density field and the magnetic flux density fields are solved separately so that the solenoidal condition is satisfied non-iteratively. The fractional step method is applied to the present coupling in the simulation. As a result of the numerical investigation, it is demonstrated that the temperature fluctuation due to turbulent mixing weakens after it runs through the magnetic field caused by the Lorentz force and thus the thermal fatigue will be suppressed. Accordingly, it is concluded that the passive control of the thermal fatigue will be possible by adding a magnetic field.
An Analytical Method for Modeling Two-Phase Gravity-Driven Drainage Systems in BOP Applications
Authors: Stakenborghs Robert , Morgan Michael L.
Published: April 2011

Two-phase gravity-driven drainage systems are used in many applications within nuclear power Balance of Plant (BOP) applications such as the drain lines for moisture separator re-heaters (MSRs) and feedwater heaters. Design of these systems is typically based on industry-oriented guidelines and operator-based experience. Changes in plant operation, such as uprates and equipment modification and/or replacement, are relatively common as plants seek to generate more power with greater efficiency. These plant modifications may inadvertently change system operation from design conditions and impose undesirable system transients. This paper seeks to provide a method for analyzing BOP drainage systems in an effort to characterize and mitigate drain flow transients. Previous methodologies diagnose and evaluate drain instability through measurement, empirical analysis, and operational experience. This paper identifies methods that can be utilized to generate computational models of discrete plant drainage systems that decrease the level of speculation involved in previous analyses. Additionally, a real-world application of this method is presented to demonstrate how computer modeling can accurately mimic plant transients.
Execution of 18 Month Refueling Modification and Experience Feedback
Authors: Sheng Guo-long , Pu Yang
Published: April 2011

The article presents how to plan, organize, and put in practice of the 18-months fuel cycle project on the newly built up nuclear plants. Some problems related to the field experience of modification and the amelioration suggestions are also provided. It’s involved that operation procedure modification, operation technical specification modification, test period prolongation, set point adjustment, boric acid concentration adjustment, re-start physical experiment and so on.
Ethical Framework for Biofuels
Authors: Buyx Alena , Tait Joyce
Published: April 2011

Biofuels policies must protect human rights and the environment.
Histopathologic Diagnosis of Fungal Infections in the 21st Century
Authors: Guarner Jeannette , Brandt Mary E.
Published: April 2011

Fungal infections are becoming more frequent because of expansion of at-risk populations and the use of treatment modalities that permit longer survival of these patients. Because histopathologic examination of tissues detects fungal invasion of tissues and vessels as well as the host reaction to the fungus, it is and will remain an important tool to define the diagnostic significance of positive culture isolates or results from PCR testing. However, there are very few instances where the morphological characteristics of fungi are specific. Therefore, histopathologic diagnosis should be primarily descriptive of the fungus and should include the presence or absence of tissue invasion and the host reaction to the infection. The pathology report should also include a comment stating the most frequent fungi associated with that morphology as well as other possible fungi and parasites that should be considered in the differential diagnosis. Alternate techniques have been used to determine the specific agent present in the histopathologic specimen, including immunohistochemistry,in situhybridization, and PCR. In addition, techniques such as laser microdissection will be useful to detect the now more frequently recognized dual fungal infections and the local environment in which this phenomenon occurs.
Laboratory Diagnosis of Tuberculosis in Resource-Poor Countries: Challenges and Opportunities
Authors: Parsons Linda M. , Somoskövi Ákos , Gutierrez Cristina , Lee Evan , Paramasivan C. N. , Abimiku Alash'le , Spector Steven , Roscigno Giorgio , Nkengasong John
Published: April 2011

With an estimated 9.4 million new cases globally, tuberculosis (TB) continues to be a major public health concern. Eighty percent of all cases worldwide occur in 22 high-burden, mainly resource-poor settings. This devastating impact of tuberculosis on vulnerable populations is also driven by its deadly synergy with HIV. Therefore, building capacity and enhancing universal access to rapid and accurate laboratory diagnostics are necessary to control TB and HIV-TB coinfections in resource-limited countries. The present review describes several new and established methods as well as the issues and challenges associated with implementing quality tuberculosis laboratory services in such countries. Recently, the WHO has endorsed some of these novel methods, and they have been made available at discounted prices for procurement by the public health sector of high-burden countries. In addition, international and national laboratory partners and donors are currently evaluating other new diagnostics that will allow further and more rapid testing in point-of-care settings. While some techniques are simple, others have complex requirements, and therefore, it is important to carefully determine how to link these new tests and incorporate them within a country's national diagnostic algorithm. Finally, the successful implementation of these methods is dependent on key partnerships in the international laboratory community and ensuring that adequate quality assurance programs are inherent in each country's laboratory network.
Economic impact of fatal and non-fatal road traffic injuries in Guadalajara Metropolitan Area and Jalisco, Mexico
Authors: Pérez-Núñez Ricardo , Ávila-Burgos Leticia , Híjar-Medina Martha , Pelcastre-Villafuerte Blanca , Celis Alfredo , Salinas-Rodríguez Aarón
Published: April 2011

Objective

To estimate the economic cost of fatal and non-fatal road traffic injuries (RTI) in Guadalajara metropolitan area (GMA) and Jalisco, Mexico during 2007.

Materials and methods

Using an incidence-based cost of illness analysis from a household perspective employing a bottom-up approach all direct medical and non-medical costs, and indirect costs were estimated for a sample of RTI people who sought care during 1 month in four different medical facilities. Individuals were surveyed just before discharge from emergency rooms (ER) and hospitalisation services. Hospitalised individuals were followed up at 8 weeks after discharge. Productivity loss was estimated with the human capital approach. Using estimated costs and administrative records of mortality and morbidity, the economic costs were dimensioned for GMA and for Jalisco. A multivariate and probabilistic sensitivity analysis was conducted to evaluate variations resulting from assumptions used.

Results

297 injured were included in the study, 20% were hospitalised and 237 only received care at ER. A total cost of US$21 190 was estimated in all injured receiving care at ER and $83 309 for those hospitalised. Direct cost represents more than 30% of reported income in 8% of the ER users and 80% of hospitalised. Total economic cost was US$329 061 813 for GMA (discount rate of 3%), nearly 51% of the state total (US$650 908 924 or 1.3% of State GNP).

Conclusions

This estimation shows the high cost (both, direct and indirect) RTI impose in households affecting their economy and leading families to lose wealth assets, get in debt or impoverished.
Review of the long-term disability associated with hip fractures
Authors: Bertram Melanie , Norman Rosana , Kemp Linda , Vos Theo
Published: April 2011

Objectives

To determine the proportion of hip fracture patients who experience long-term disability and to re-estimate the resulting burden of disease associated with hip fractures in Australia in 2003.

Methods

A literature review of the functional outcome following a hip fracture (keywords: morbidity, treatment outcome, disability, quality of life, recovery of function, hip fractures, and femoral neck fractures) was carried out using PubMed and Ovid MEDLINE.

Results

A range of scales and outcome measures are used to evaluate recovery following a hip fracture. Based on the available evidence on restrictions in activities of daily living, 29% of hip fracture cases in the elderly do not reach their pre-fracture levels 1 year post-fracture. Those who do recover tend to reach their pre-fracture levels of functioning at around 6 months. These new assumptions result in 8251 years lived with disability for hip fractures in Australia in 2003, a 4.5-fold increase compared with the previous calculation based on Global Burden of Disease assumptions that only 5% of hip fractures lead to long-term disability and that the duration of short-term disability is just 51 days.

Conclusions

The original assumptions used in burden of disease studies grossly underestimate the long-term disability from hip fractures. The long-term consequences of other injuries may similarly have been underestimated and need to be re-examined. This has important implications for modelling the cost-effectiveness of preventive interventions where disability-adjusted life years are used as a measure of health outcome.
Participation of bile ductular cells in the pathological progression of non-alcoholic fatty liver disease
Authors: Chiba Mayumi , Sasaki Motoko , Kitamura Seiko , Ikeda Hiroko , Sato Yasunori , Nakanuma Yasuni
Published: April 2011

Aims

Non-alcoholic fatty liver disease (NAFLD) represents a spectrum of pathological conditions, ranging from simple steatosis to hepatic fibrosis with progression to cirrhosis. While activated hepatic stellate cells (HSC) are known to be involved in intralobular, perisinuosidal fibrosis, the mechanisms of portal and bridging fibrosis remain speculative. This study investigated the roles of bile ductules in portal and septal fibrosis.

Methods

48 liver biopsies were obtained from NAFLD patients. These cases were divided into four stages according to the Brunt classification.

Results

Bile ductules positive for CK19 were increased along with the progression of staging and fibrosis of NAFLD, and the increased bile ductules were associated with portal inflammation and fibrosis. The cellular senescence marker; p16INK4aand p21WAF1/Cip1-positive bile ductular cells were increased in stages 3 and 4. Such senescent bile ductules frequently express chemotactic protein, CCL2 (MCP-1), which may be responsible for chemoattraction of activated HSC around the bile ductules in portal and septal fibrosis and for portal inflammation. The migration of cultured mouse HSC was significantly facilitated in the presence of cultured senescent mouse biliary epithelial cells (BEC), and this migration was mediated by CCL2 secreted from senescent cultured BEC. Small spindle-like cells positive for CK7 alone in the hepatic parenchyma in the advanced stage seem to differentiate to periportal bile ductular cells positive for CK19 and CK7.

Conclusions

It seems possible that increased bile ductules expressing cellular senescence markers and chemokines are at least partly involved in the progressive portal and bridging fibrosis in NAFLD.
Water wave transients in an ice-covered channel
Authors: Nzokou François , Morse Brian , Robert Jean-Loup , Richard Martin , Tossou Edmond
Published: April 2011

Many studies show that the propagation of a breakup water surge in impeded rivers (ice cover present) differs from the unimpeded case. Some of the differences are due to ice sheet breaking into pieces as the wave travels downstream while others are due to the effect of a fissured but otherwise intact ice cover’s resistance to motion. This is the subject of this paper: water waves that are sufficiently strong to break the cover away from the banks but not strong enough to create transverse cracks. Although some analytical solutions exist for the propagation of these transients for simple cases, for the first time in the literature, this paper introduces numerical solutions using a FEM model (HYDROBEAM) that simulates this interaction using the one-dimensional Saint-Venant equations appropriately written for rivers having an intact fissured floating ice cover coupled with a classic beam equation subject to hydrostatic loads (often referred to as a beam on an elastic foundation). The governing equations are numerically expressed and are solved using a finite element method (FEM) for the hydrodynamic and ice beam equations separately. A coupling technique is used to converge to a unique solution at each time step (for more information on the numerical characteristics of the model, see companion paper presented by the authors in this issue). The coupled model, gives a first and unique opportunity to compare the simplified analytical solutions to the full numerical solutions. A parametric analysis is herein presented that quantifies the impact of the ice cover's presence and stiffness on wave attenuation and wave celerity as well as to quantify tensile stresses generated in the ice sheet as a function of ice properties (thickness and strength) and channel shape (rectangular and trapezoidal). In general, for rectangular channels, it was found that the simplified analytical solutions are quite representative of the phenomenon namely that short wave transients are affected by the cover’s stiffness but long waves (>400 m) are not.