bluuebunny/crossref_metadata_2025 huggingface dataset:
Future Trends in Engineering Design and Education: An Aerospace Industry Perspective
Authors: McMasters John H.
Published: March 2009

This paper is a continuation of the author’s previous examinations of a suite of issues surrounding the putative decline in aerospace (and aeronautics in particular) conducted under the auspices of the American institute of Aeronautics and Astronautics (AIAA). The purpose of this paper is to use recent aerospace industry experience as a lens for examining four specific issues believed to be of broader importance to the future of our industry and others as well. The first is the question of how many engineers we may need in our future as we confront the problem of an aging workforce and the globalization of our industry. The second is the question of what skills and abilities these engineers will need to possess as the overall industry continues to evolve. Third is the pervasive need for more systems-oriented, multidisciplinary-skilled talent. Finally, the issue of what academe needs to do to support the development of a future generation of engineering talent is addressed. A basic message of this paper, carried on from earlier writings, is that while aerospace may indeed be a “maturing industry” (at least in some major traditional product areas), there is much that we can and should do to create a vision of our future as vivid as that which has driven our past as a means to attract, educate and develop the talent needed to assure the future of our enterprise. Without this talent, few of the major technological advances that can be currently foreseen can come to fruition.
Visualization of Micro-Scale Bubble Dynamics in Pure Liquids and Aqueous Surfactant Solutions
Authors: Raghavan S. Sethu , Manglik Raj M.
Published: March 2009

Growth and departure of a single adiabatic bubble in pure liquids and aqueous surfactant solutions is visualized. High-resolution photographic records are obtained that characterize the micro-scale bubble dynamics (shape, size, and post-departure translation), the mean bubble diameter at different time periods of its growth and departure, and the bubble surface age (the time interval from the newly formed interface to the attainment of departure diameter). This pre- and post-departure dynamics of air bubbles is visualized in water, N, N dimethyl-formamide (DMF), and ethyl alcohol (all pure liquids), and aqueous surfactant solutions of SDS (1250 wppm, 2500 wppm, and 5000 wppm), CTAB (200 wppm), and Triton X-305 (1000 wppm). The evolution of different bubble shapes, sizes, and departure frequencies is presented to highlight the effects of surface-active forces. In the case of surfactant solutions, the dynamic effects of the molecular-scale adsorption-desorption dynamics of the additive at the liquid-air interface that manifests in the dynamic surface tension is also delineated.
Effects of Late Intake Valve Closing on Four Stroke Gasoline Engines
Authors: Parvate-Patil G. B. , Hong H. , Gordon B. W.
Published: March 2009

The objective of this paper is to the study effects of Late Intake Valve Closing (LIVC), and how it affects the in-cylinder fluid flow for four stroke gasoline engines. Further investigation of LIVC has been performed with the help of an engine cycle simulation program (GT-Power). Study shows that LIVC is beneficial for reduction of pumping losses, which may reduce the break specific fuel consumption (BSFC) of the engine. In this paper, a simulation of LIVC was achieved by retarding the timing of the solenoid actuated intake valve.
Effects of Vacuum Enhancer on the Flow Fields in a Quick Injection Agitator
Authors: Youn K.-J. , Ahn B.-J. , Kim Youn J.
Published: March 2009

An agitator is generally used in the chemical and food industries, and water treatment plants. The water treatment processes are to be classified into rapid mixing, coagulation, precipitation, filtration and sterilization. Rapid mixing process is the smallest scale and its dispersion time is short. It is a very important process because it gives significant effects on the following processes. A quick injection agitator is used to mix water and many kinds of chemicals. A quick injection agitator has superior mixing characteristics that represent a major step forward in the water treatment. It consists of a motor driven open propeller, which creates a vacuum in the chamber directly above the propeller. This vacuum is transmitted to the chemical metering/control systems by a vacuum line similar to current remote injection systems. The most important design parameters are velocity gradient and dispersion time in a quick injection agitator. Velocity gradient is changed by the shape of the propeller and vacuum in a space between the propeller and the vacuum enhancer. In this study, numerical analyses are carried out to investigate the characteristic of flow in a quick injection agitator with various gaps between the propeller and the vacuum enhancer. A commercial CFD code is used to compute the 3-D viscous flow fields within the propeller of the agitator. Numerical results are graphically depicted with different velocity gradients. Special attention is paid to following topics: pressure distribution, velocity gradient, and void fraction.
Flow and Noise Characteristics of Airfoils With Application to Turbomachinery
Authors: Lee S. , Kim H.-J. , Song W.-S. , Culick F. E. C. , Fujisawa N.
Published: March 2009

The flow-fields around airfoils in a uniform flow under the generation of noise were numerically studied and compared with experimental data. The numerical simulation was carried out by a large-eddy simulation that employs a deductive dynamic model as a subgrid-scale model. The result for a symmetrical airfoil at small angle of attack α = 3°–6° indicates that the discrete or narrow-banded frequency noise is generated when the separated laminar flow reattaches near the trailing edge of the pressure side and a strong instability thereafter affects positive vortices shed near the trailing edge. This type of forced transition or late transition instabilities near the trailing edge of the pressure side, interacting with convected vortices in an attached T.B.L. on the suction side, can be found in many practical airfoils of impellers rotating at moderate speeds under design conditions. The sound spectra derived from the aero-acoustic computations of airfoils indicate a dipole nature of sound having a narrow-banded or discrete peak by laminar instability and turbulent vortex shedding from their trailing edges of finite thickness at a Strouhal frequency, a quadrupole sound by turbulent broadband boundary-layer noise, or a mixed mode depending on flow conditions near the T.E.
Study of Film Cooling on a Cascade Using Infrared Thermography
Authors: Han Zhenxing , Liu Shi , Suenaga Kiyoshi
Published: March 2009

This paper studies the effect of two given free-stream turbulence intensities on film cooling at different blowing ratios on one cascade, made up of five blades. Experiments on the suction side were done at three different blowing ratios 0.5,1.0 and 1.5; those on the pressure side were done at four different blowing ratios, 0.5,0.75,1.5 and 1.75. The two given free stream turbulence intensities are 0.5% and 5% respectively. In these experiments, we adopted infrared thermography to capture the images of temperature distributions on blade surface. According to the experimental results, the turbulence acts on the effectiveness distributions differently on the pressure side and suction side due to the existence of blade curvature. Bigger turbulence intensity can worsen the cooling effect on both the suction side and the pressure side.
Expanding the Role of Stirling Engines
Authors: Beach Eugene , Karchnak Martin F. , Ball John
Published: March 2009

Stirling engines are being used more and more frequently in applications such as Combined Heat and Power (CHP). Federal projects have a history of employing Stirling technology to address critical needs. Exploitation of certain alternative energy approaches such as the increased reliance on Bio-Mass energy inherently argues the Stirling case. This paper examines this expanded role for Stirling technology, while also examining the potential impacts achievable from the application of modern technologies. Examples of modern technologies include improved control technologies, new materials and new design approaches. Specific examples of successes are documented, and typical future choices are identified and appraised. The functional advantages of Stirling technology are likewise enumerated and discussed. They range from a variety of economic and technical advantages (fuel diversity, quietness, pristine environmental character, lubrication friendliness,...), through the most basic advantage that Stirling engines possess relative to many competing technologies, namely the fact that there are ‘no showstoppers’ with Stirling engine technology (implemented since 1816). An assessment is provided relative to some of the limitations of previous Stirling engine design approaches, and suggestions are provided regarding how such limitations and concerns can be addressed with the expanding role of Stirling engines.
Effect of Buoyancy on Room Air Flow
Authors: Tripathi B. , Arora R. C. , Moulic S. G.
Published: March 2009

Thermal comfort and ventilation needs of spaces are met by supplying “conditioned” air, which is a blend of outdoor and recirculated air that has been filtered, heated or cooled, and sometimes humidified or dehumidified. Comfort conditions in air-conditioned rooms require that temperature in the occupied zone should not vary by more than 1°C and velocity, every where in the room, should be less than 0.15 m/s so that occupants do not feel draft. Recent developments in providing effective insulation and making leak tight building shell have considerably reduced the cooling load requirements and the supply airflow rates. Obtaining uniform temperature distribution with reduced air volume flow rates requires careful design of air distribution system. This study aims to find velocity and temperature distribution in the room towards this end. Coanda effect, effect of buoyancy and wall boundary layers has been observed in this investigation. The Coanda effect is observed in all the cases of laminar flow. Cold fluid enters in the room near the ceiling, the flow attaches with the ceiling, comes down along the right wall and goes out from outlet.
Effects of Non-Dimensional Parameters on Formation and Break Up of Cylindrical Droplets
Authors: Taeibi-Rahni Mohammad , Sharafatmand Shervin
Published: March 2009

The consistent behavior of non-dimensional parameters on the formation and break up of large cylindrical droplets has been studied by direct numerical simulations (DNS). A one-fluid model with a finite difference method and an advanced front tracking scheme was employed to solve unsteady, incompressible, viscous, immiscible, multi-fluid, two-dimensional Navier-Stokes equations. This time dependent study allows investigation of evolution of the droplets in different cases. For moderate values of Atwood number (AT), increasing Eotvos number (Eo) explicitly increases the deformation rate in both phenomena. Otherwise, raising the Ohnesorge number (Oh) basically amplifies the viscous effects.
Effect of Temperature Variation on Nickel Cadmium (Ni-Cd) and Nickel Metal Hydride (Ni-MH) Battery Parameters
Authors: Ghassemi Majid , Afshari Ebrahim
Published: March 2009

The ultra-fast charging capability, distinct properties, fine performance and high capacity of nickel cadmium (Ni-Cd) and nickel metal hydride (Ni-MH) batteries along with their limited weight and size are very attractive for use in many applications including cordless and portable devices, emergency and standby power, telecommunication equipments, photovoltaic systems, electric vehicle, satellite and space craft and power plant supporting equipments. However, the limitation on their temperature requires a detail thermal analysis of these batteries. Thermal behavior of batteries are effected by their boundary conditions, type and construction, and more importantly by their chemical reaction. The purpose of this study is to investigate the effect of temperature on thermal behavior of the Ni-Cd and Ni-MH batteries. The governing equation is the transient and non-linear differential energy equation subjected to non linear radiation boundary conditions and source term. To solve the transient and non-linear governing differential energy equation a control volume based finite difference code is utilized. In formulation of the governing differential energy equation, the Ni-Cd and Ni-MH properties (K, C, ρ) are not constant and the chemical characteristic of the Ni-Cd and Ni-MH batteries, source term, vary with location and time. Calculated thermal characteristic of each battery is then compared to experimental results. The result shows that Ni-MH battery is thermally more suitable for space application and satellite.
Non-Invasive Ultrasonic Interrogation of Dense Slurries
Authors: Bamberger Judith Ann , Greenwood Margaret S.
Published: March 2009

Staff at Pacific Northwest National Laboratory has developed a compact, non-invasive, ultrasonic interrogation technique to characterize fluid or dense slurry during pipeline transport or in process vessels during mixing or settling. The ultrasonic transducers are mounted directly on the outside of the process container or pipe spool piece so the pipe or vessel wall becomes part of the measurement system. The transducers are pulsed to measure the density, speed of sound, and attenuation of the signal which penetrates the pipe wall and through the slurry. These signals are analyzed to determine fluid density, solids concentration, and track changes in particle size. Analysis of multiple signal reflections provides increased measurement sensitivity.
Energy Balance for a Direct Carbon Molten Carbonate Fuel Cell
Authors: Agarwal Ritesh , Kornhauser Alan A.
Published: March 2009

A novel fuel cell design uses porous bed electrodes. Liquid electrolyte, with fuel and oxidizer entrained, is circulated through the electrodes. An energy balance has been done for the cell and auxiliaries. The design calls for the CO-CO2 mixture leaving the anode to be burned to supply an O2-N2-CO2 mixture to the cathode. Two heat exchangers are employed: an air preheater cooling the exhaust and a waste heat exchanger cooling the gases entering the cathode. Results show that CO/CO2 ratio is the most important parameter for determining performance. For other conditions ideal, plant efficiency varies from ∼90% for pure CO2 to ∼20% for pure CO. If decoupled from CO/CO2 ratio, the main effect of increasing cell temperature is to increase heat transfer rate in the air preheater. This is also the main effect of increasing excess air. Decreasing internal cell efficiency lowers power output and increases waste heat rejection.
Measurement of Fuel Regression Rates in a Jet Fuel Pool Fire in Crosswind
Authors: Randsalu Eerik J. , Lam Cecilia S. , Weckman Elizabeth J. , Brown Alexander L. , Gill Walter
Published: March 2009

Fire modeling software has become increasingly important for the prediction of fire development in industrial and transportation accident scenarios. A key parameter required as input to fire models is the rate at which the fuel load is consumed, often reported as the fuel regression rate. This variable is linked to the energy output of the fire in a tightly coupled, cyclical fashion [1] and, for the most part, must be determined experimentally for model verification. Measurement of fuel regression rate proves to be difficult and is further complicated by the fact that ambient winds are typically significant in large accident scenarios. Wind is known to greatly affect fire behavior [2,3].
Boundary Layers With Viscous Potential Outer Flows
Authors: Najafiyazdi Alireza
Published: March 2009

In this paper we try to derive improved formulations for laminar boundary layers in incompressible flows by using the concept of viscous potential flows, presented in Joseph [1] and Joseph [2], as the outer flow. Bernoulli’s equation is used at the edge of boundary layer to make the basic assumption to deduce the presented formulas. The momentum equation is derived directly from the Navier-Stokes equations and then simplified using an order of magnitude analyze. However an additional term, μ∂2u∞∂x2, remains in the momentum equation to represent the contribution of the viscosity of the outer potential flow at the edge of the boundary layer. The viscosity of the outer viscous flow shows itself also in momentum-integral and energy-integral equations. Numerical results showed that at high Reynolds numbers and low angles of attack the results of the two formulas are almost the same, but for lower Reynolds numbers and higher angles of attack the difference between the results is remarkable.
Deconvolution of Temperature and Soot Volume Fraction in a Turbulent Ethylene Flame by Inverse Spectral Radiation Analysis
Authors: Zheng Yuan , Gore Jay P.
Published: March 2009

We report a new non-intrusive diagnostics technique for the simultaneous reconstruction of temperature (T) and soot volume fraction (fv) profiles in axi-symmetric turbulent luminous flames. Line-of-sight spectral radiation intensities (Iλ) for one diametric and nine chord-like radiation paths from a representative horizontal plane of a turbulent ethylene jet flame were measured by a fast infrared array spectrometer. By inverse analysis of the measured mean Iλ at four wavelengths where continuum radiation from soot particles dominates, four local scalar statistics, including mean and root-mean-square (rms) of T and fv, were de-convoluted. Powell’s conjugate-gradient algorithm and Brent’s line minimization algorithm were adopted in solving the present four-variable inverse problem. The calculated mean Iλ matched the experimental data very well within a 3% difference in general. The reconstructed local mean/rms T and fv distributions were in reasonably good agreement with sampling data from similar turbulent flames.
Measurement of Heat Flux From Fires
Authors: Lam Cecilia S. , Brown Alexander L. , Weckman Elizabeth J. , Gill Walter
Published: March 2009

Heat flux is an important parameter for characterization of the thermal impact of a fire on its surroundings. However, heat flux cannot be measured directly because it represents the rate of heat transfer to a unit area of surface. Therefore, most heat flux measurements are based on the measurement of temperature changes at or near the surface of interest [1,2]. Some instruments, such as the Gardon gauge [3] and the thermopile [2], measure the temperature difference between a surface and a heat sink. In radiation-dominated environments, this difference in temperature is often assumed to be linearly related to the incident heat flux. Other sensors measure a surface and/or interior temperature and inverse heat conduction methods frequently must be employed to calculate the corresponding heat flux [1,4]. Typical assumptions include one-dimensional conduction heat transfer and negligible heat loss from the surface. The thermal properties of the gauge materials must be known and, since these properties are functions of temperature, the problem often becomes non-linear.
Different Pathways of Secondary Phase Formation Induced by Colloidal and Dissolved Silica During the Dissolution of UO2 Nuclear Fuel in Leaching Tests
Authors: Amme M. , Lang H. , Sto¨ckl M.
Published: March 2009

We investigated the different dissolution behaviour of UO2 nuclear fuel material in waters containing silica in two different physical and chemical forms (dissolved ions and as SiO2 colloids, respectively) at elevated temperatures (95 °C in autoclaves). It was investigated if SiO2 colloids can act as carrier material for U ions during a interface geochemical dissolution process, a process that might possibly enhance the mobilization of uranium. Herefore, leaching / dissolution tests were conducted in batch reactors, using both dissolved Si (sodium metasilicate solution), as well as synthetic SiO2 colloids (100 nm diameter). Solid materials were examined with scanning electron microscopy (SEM-EDX) after the tests and ICP-OES was used for analysis of concentrations of U and Si in solutions. Thermodynamic calculations were applied for modelling the surface charges of the solid materials. Results show that a treatment with colloidal SiO2 has different effects on the surfaces than a leaching in dissolved silicate solutions. In the presence of colloids, well-crystallized secondary phases containing U and Si (most obviously uranyl silicates) were found on the surfaces, which were attacked by the treatment. This was not the case when dissolved Si was used. SiO2 colloids were partly found to remain on the surfaces after 1000 h at 95 °C. Dissolved U concentrations decreased with increasing Si content in the systems, especially so when colloidal Si was used. Ultrafiltration showed that the greatest part of the dissolved U was associated with Si colloids. A surface charge model suggests that the different effects are due to the development of electrostatic interactions between the UO2 and SiO2 surfaces.
Current Status of Radioactive Waste Disposal in Russia
Authors: Gupalo T. A. , Lopatin V. V. , Lobanov N. F.
Published: March 2009

A huge amount of radioactive waste has been accumulated in the Russian Federation (RF) in the course of implementation of the defense and energy programs, industrial and research activity involving the use of nuclear materials. The most justified and technically feasible technology of solidified RW isolation is its disposition in low-permeable geological formations in specially constructed underground facilities. Today in Russia a Closed Fuel Cycle (CFC) has been adopted, at the CFC final stage the spent nuclear materials and radioactive waste have to be isolated from the biosphere for the whole term of their potential hazard. In Russia, in accordance with the regional approach to the decision of Radioactive Waste (RW) disposal problem, several candidate disposal sites have been assigned.
Comparative Quantitative Estimation of Engineered and Natural Barriers Influence on Ecological Safety of Long-Lived Radwaste Underground Disposal
Authors: Gupalo T. A. , Beygul V. P. , Konovalov V. Yu.
Published: March 2009

The paper presents quantitative estimations of the effect of containers, matrix materials, bentonite barrier and hard rock massif on ecological safety during geologic isolation of longlived RW. The estimations were obtained on the basis of mathematical modelling of radionuclides (Np-237, Tc-99, Pu-239, Zr-93) migration in bentonite barrier, forecasting contaminated underground water migration in fractured zones, experimental data on leaching rates of radionuclides immobilized in boron silicate glasses and mineral-like ceramics. Preliminary data obtained at one of the sites of the Nizhnekansky massif were used in calculations. Is was shown that choice of optimum performances of multibarrier system can ensure safe final isolation of long-lived, not heat-generating RW fractions in geologic disposal located at 600 m depth.
Windscale Pile 1: A New Approach
Authors: Milburn A. H.
Published: March 2009

One of the most technically challenging reactor decommissioning projects in the UK, if not the world, is being tackled in a new way managed by a team lead by the United Kingdom Atomic Energy Authority. Windscale Pile 1, a graphite moderated, air cooled, horizontal, natural uranium fuelled reactor was damaged by fire in October 1957. De-fuelling, initial clean-up and isolation operations were carried out in the 1960’s. During the 1980’s and 90’s a successful Phase1 decommissioning campaign resulted in the plant being cleared of all accessible fuel and graphite debris and it being sealed and isolated from associated facilities and put on a monitoring and surveillance regime while plans for dismantling were being developed. For years intrusive inspection of the fire damaged region has been precluded on safety grounds. Consequently early plans for dismantling were constructed using pessimistic assumptions and worst case predictions. This in turn lead to technical, financial and regulatory hurdles which were found to be too high to overcome. The new approach utilises the best from several areas: • The design process incorporates principles of the US DoE safety analysis process to address safety, and adds further key stages of design concept and detail to generate concurrent development of a technical solution and a safety case. • A staged and gated Project Management Process provides for stakeholder involvement and consensus at key stages. • Targeted knowledge acquisition is used to minimise uncertainty. • A stepwise approach to intrusive surveys is employed to systematically increase confidence. The result is a process which yields the optimum solution in terms of safety, environmental impact, technical feasibility, political acceptability and affordability. The change from previous approaches is that the project starts from the hazards and associated hazard management strategies, through engineering concept, to design manufacture and testing of the resulting solution rather than starting with the engineer’s “good idea” and then trying to make it work, safely and at an affordable price. Progress has been made in making the intrusive survey work a reality. This is a significant step in building a realistic picture of the physical and radiological state of the core and in building confidence in the process.
Possibility for Incineration of Spent Graphite Sleeves From Plutonium-Production Reactors of the SGCE (Tomsk-7)
Authors: Bushuev Anatoly , Petrova Ekaterina , Aleeva Tatiana , Zubarev Victor , Nikolaev Andrey , Semenov Vladimir , Silin Boris , Dmitriev A. M.
Published: March 2009

For the lengthy process of different reactor types operation, huge amounts of spent graphite were accumulated in several countries. Spent reactor-grade graphite constitutes the largest fraction of the solid radioactive wastes accumulated all over the world. So, search for ways of spent graphite utilization is an urgent problem of international character. The purpose of the present work is to evaluate radioactive contamination of spent graphite sleeves from decommissioned reactors I-1, EI-2, ADE-3 of the Siberian Group of Chemical Enterprises and to consider a possibility for spent graphite sleeves utilization by incineration. Planning of actions on spent graphite management requires to take into account the reactor type, properties of spent graphite, peculiarities of spent graphite usage and storing. Beginning from 1996, authors have conducted the detailed studies on radioactive contamination of spent graphite from the SGCE reactors. In these studies, contents of some radionuclides in spent reactor-grade graphite were measured, including content of isotopes generated by neutron-induced activation of impurities (60Co, 3H, 14C, etc.) and the isotopes generated in result of uranium penetration into the graphite reactor components (137Cs, 90Sr, 241,243Am, 244Cm, Pu isotopes, etc.). It was revealed the largest contribution to the graphite radioactivity was given by 14C. Using data on inhalation and ingestion rate for different age groups, the evaluations were carried out for 14C intake into human organism with air and food. Analysis of the results obtained in the performed investigation enabled us to make the following conclusions: 1. the most part of the SGCE storage vaults where spent graphite sleeves are disposed of do not meet contemporary requirements; 2. the radioactive contamination level of spent graphite sleeves from the SGCE reactors allows their utilization by incineration at the SGCE territory; 14C exhaust into the atmosphere will not cause any significant risk of negative consequences for human health of cities Seversk and Tomsk population; 3. spent sleeves incineration and subsequent storing of incineration products can not lead to appearance of nuclear dangerous situation; 4. there is an available technology and associated equipment for conduction of experiment on spent graphite incineration. Thus, it can be concluded that nowadays there are all the conditions for planning, preparation and conduction of fullscale experiment on incineration of some spent graphite sleeves taken from the SGCE storage vaults. The results obtained in the test graphite incineration will allow to evaluate and, if necessary, improve the utilization technology and the applied equipment.
Self-Sustaining Immobilisation Processes
Authors: Ojovan Michael I. , Karlina Olga K. , Petrov George A. , Sobolev Igor A. , Dmitriev Sergey A. , Lee William E.
Published: March 2009

As overview of self-sustaining immobilisation processes is given which describes also new thermochemical and radiogenic heat immobilising schemes based on utilization of both exothermal chemical reactions and radioactive decay energy.
Building the Yucca Mountain Repository
Authors: Vawter R. Glenn
Published: March 2009

The U.S. Congress recently approved the Yucca Mountain Project in Nevada as the site for the nation’s high level nuclear waste repository. The Project now moves into the licensing, construction and operating phases. The question posed by this paper is what organization approach is best suited to carry out those functions as well as the affiliated transportation and waste acceptance activities? Currently the U.S. Department of Energy and its contractors are responsible for the implementation of the Project. Other alternatives include a government corporation, private industry, a different U.S. government agency, or a combination of the above? There are pros and cons to each approach. This paper will present pros and cons and discuss the implications of each alternative. It will also discuss experience from other similar endeavors around the world. The U.S Federal Administration will need to consider this important question to assure the success of the program, because it is so important to the energy and national security of the nation. And its success or failure will set a precedent for repository programs around the world.
EIA Processes in the Radioactive Waste Management in Slovakia: Eight Years of Experience
Authors: Salzer Peter , Sencˇa´kova´ Eva
Published: March 2009

Environmental Impact Assessment Act has been in force in the Slovak Republic since 1994. Evaluation of potential environmental impact of nuclear facilities/activities was enforced in the cases of newly sited constructions containing nuclear facilities much earlier: the civil construction legislation required the preparation of initial safety report with the same purposes. The cardinal change constituted by the EIA Act was the legal requirement of the public involvement in the assessment process, such as participation of municipalities, civil initiatives or public hearings. Another aspect was the most complex evaluation of impact, i.e. not only inside the nuclear safety framework but including, for instance, also non-nuclear, social, and economical aspects. All nuclear activities judged by the environmental impact assessment processes in the last eight years have been related to radioactive waste and spent fuel management facilities or activities and to the decommissioning of nuclear power plants. The particular cases are briefly described and the positive and negative implications from particular environmental impact assessment processes are discussed and generalized. Special attention is given to the use of EIA approaches in the strategy decision-making processes on various levels. There are the main difficulties and drawbacks in application of the EIA legal provisions in Slovakia at the present time.
Decontamination and Provenance Tracking
Authors: Bradbury David , Elder George R. , Ritchie John C. , Ward Robert G.
Published: March 2009

Decommissioning of retired nuclear plants and facilities demands the proper management of the process, both for economic reasons and for retaining public confidence in the continued use of nuclear power for electricity generation. There are significant potential benefits, both economic and environmental, in recycling materials from retired nuclear facilities for new uses rather than disposing of them as radioactive waste. Although it is technically possible to decontaminate many retired nuclear components to reduce contamination levels to below those appropriate for free release into the public domain, there is some public unease at the prospect of formerly contaminated materials passing into unrestricted public use. Greater support for recycle can be achieved by converting decontaminated materials into products for new controlled uses, particularly within the nuclear industry. Irrespective of the future of nuclear power, the industry has a need for many new items such as waste containers, replacement components etc. Good economics can be achieved by decontaminating the materials and then using existing non-radioactive manufacturing facilities for fabrication of new components. Provided that materials have first been decontaminated to below unrestricted release levels, there is no objection in principle to using non-radioactive facilities for recycling and manufacturing activities, so long as the materials are properly tracked to prevent their uncontrolled release. Surface decontamination has an important role to play in these activities. Efficient and economic decontamination processes are needed to prepare materials for recycle. The EPRI DFDX Process is a process for achieving these objectives. Recent progress with this process is described.
Providing Better Information for Public Participation in Contentious Decisions
Authors: Orr P. , Collier D.
Published: March 2009

It is widely recognised today that involving stakeholders and members of the public in decision-making has a number of significant benefits, such as increasing the legitimacy of decisions and incorporating lay values and perspectives. This has focussed attention on how to allow for meaningful participation by stakeholders. Much research has been done to develop and evaluate different methods for public participation. Looking beyond the specific techniques employed, to questions such as relations of power between stakeholders, it becomes clear that the provision of information, both on the nature of the process itself and on the issues under consideration, is at the heart of all participation. Using information to increase openness and effective input from a diversity of stakeholders is especially challenging when the issues are technically complex and contentious. Risk communication research has demonstrated that perceived transparency and objectivity in the provision of information are factors that contribute to public trust in experts and institutions. Progress has been made in understanding what procedures are appropriate for giving information at different stages in the decision-making process. In the UK, less attention has been paid to the content of the risk information itself. A review has, therefore, been undertaken of the experience of the Environment Agency of England and Wales of developing and providing information in the context of major public consultations on contentious environmental issues, in particular, for proposed environmental licences for discharges from nuclear power plants. The review has identified a number of areas in which progress needs to be made with respect to: • information to support stakeholder involvement in “framing” the issues; • the scope of information that is appropriate in different decision-making contexts; • level of detail; • the use of diverse — and even conflicting — sources; • handling questions outside the competence or remit of the organisation; • time and resource issues. These questions are important since the kind of information and the way it is provided in consultations on contentious issues affect the decisions that are made. When stakeholders are not told about the issues that they see as important or when they feel excluded from debate by the use of technical language, they will often be unwilling to participate in the process on the terms proposed. Consequently, the decision-maker may be deprived of valuable knowledge and experience, putting in question the validity of the decision, or even face stakeholder action to block the entire process. This has significant implications for the development of activities seen as having an environmental impact, and can often involve both public institutions and private operators in heavy costs. The results of this work are relevant to practitioners who are seeking to improve public participation processes, particularly on complex or contentious issues.
A Constitutive Law of Salt Concrete Used for Closure of an LILW-Repository
Authors: Engelhardt H. J. , Kreienmeyer M. , Lerch C. , Mu¨ller-Hoeppe N. , Ko¨ster R. , Eilers G. , Preuss J.
Published: March 2009

The Repository of LILW Radioactive Waste Morsleben (ERAM) is located in the Federal State Saxony Anhalt, Germany. After an operational phase of about 20 years it is now under licensing for closure. As the repository was erected in a former salt mine, there exists a void volume of approx. 6 million m3. Consequently, a closure concept was developed serving three main functional requirements: stabilization, limitation of leaching processes and sealing. It relies on a comprehensive backfilling of the openings using two mixtures of salt concretes. The concretes will be used to backfill cavities as well as to construct seals. As the salt concretes are used in the sense of a mass concrete the heat of hydration induces thermal restraint stresses inside the concrete bodies and the neighboring rocks. To show the integrity of the geological and technical barriers thermo-mechanical computations were carried out. In the numerical code which is used for safety analyses a so-called hydration model was implemented describing the evolution of strength and Young’s modulus of the concretes in relation to the degree of hydration. The hydration model includes a transformation of the temperature-dependent setting process from real time into an equivalent age, which is equal to the setting time at a temperature of 293 K. Thereafter, a coupling of the equivalent age to the degree of hydration leads to a temperature-independent description of the setting process. As the hydration of concretes strongly correlates with the amount of the generated hydration heat, the model parameters were derived from laboratory tests including measurements of the adiabatic temperature rise.
Plans for Establishment of Near Surface Repository for Low- and Intermediate-Level Short Lived Radioactive Waste in Lithuania
Authors: Vaidotas Algirdas , Jan•nas Dainius
Published: March 2009

The decision to close Ignalina NPP has significantly increased the urgency for a repository for low- and intermediate-level waste in Lithuania. It is generally considered necessary to have a licensed repository in operation before dismantling activities are initiated in order to avoid large and unnecessary costs for interim storage of waste. In the frame of bilateral cooperation with Sweden, consortium of three Swedish companies SKB-SWECO International-Westinghouse Atom developed and in the year 2002 presented to RATA reference design of a near surface repository in Lithuania. This reference design is applicable to the needs of Lithuania, considering its hydro-geological, climatic and other environmental conditions and is able to cover the expected needs in Lithuania for at least twenty years ahead. The basic principles for the proposed reference design are location above the ground water, foundation on firm basis, rock, densified sand or equivalent, a hill-type construction with vaults and engineered low-permeable clay based barrier consisting of smectitic clay of sedimentary origin covered by a surface barrier. The engineered barriers consist of the waste matrix, the waste packagings, the disposal container outer concrete, backfill between disposal containers, concrete cells surrounded by low-permeable clay-based material, all covered by long-lasting surface barrier with an erosion-resisting top. Water will be drained off by the surface barrier and collected in run-off ditches. The proposed reference design was accepted by authorities as a basis for further development of the repository in Lithuania. In the overall plan for the implementation of the repository prepared by RATA it is foreseen that repository should be in licensed operation in the year of 2011 depending on financing provided. The total cost of the repository project is estimated to be in the order of 140–240 MEUR. This year RATA is starting site selection phase which consists of area survey, regional mapping, screening, site characterisation and site confirmation.
Analysis of Environmental Friendliness of Advanced Nuclear Fuel Cycle in Korea
Authors: Kim Yong Han , Lee Kun Jai , Oh Won Zin
Published: March 2009

In order to show that the nuclear energy could be a clean energy, radioactive waste management, especially high level waste has to be successfully managed and also accepted by the public. As discussed, progressed and focused at GEN IV international project, reduction of long lived actinide source term and corresponding toxicity through transmutation process has been recognized as one possible solution to the problem and draw lots of attention these days and active R&D efforts are pursued and progressed worldwidely. Especially, much of interest has been initiated to the accelerator driven system (ADS) for the transmutation of the actinide as a subcritical reactors or combination to fast reactor (FR) to generate energy and transmute the HLW simultaneously in a cleaner and safer ways. This study compare and clarifies the roles and merits of the FR and ADS, which would be expected to be introduced into the future Korean nuclear fuel cycle partly, in view of environmental friendliness especially with the existing nuclear fuel cycle dominated by PWR in Korea. After selecting the most plausible and appropriate reactor strategy scenario, the mass flow balance of active radionuclides from ore to waste for several cases of advanced nuclear fuel cycle (where “advanced nuclear fuel cycle” means the nuclear fuel cycle with FR or ADS) is analyzed by computer code. Advanced nuclear fuel cycle with only FR or ADS, and with both FR and ADS were considered for this analysis. A spread sheet type of code, that compute material flow and some environmental friendliness indices chronologically, was developed and analyzed for the calculation. Some indices for the environmental friendliness (i.e. amount of actinide nuclides, radioactivity and radiotoxicity of them, and uranium resource requirement) for several types of advanced nuclear fuel cycles are analyzed comparing with those of once-through fuel cycle. According to the final results, it confirmed quantitatively that the advanced fuel cycle with FRs and ADSs would be one of the possible alternatives to relieve the burden of HLW waste management because those fuel cycle options might reduce the generation of the transuranic radionuclides by tens to hundreds times less compared to that of once-through fuel cycle. Especially advanced nuclear system combined with FR and ADS shows much better effects compared to not combined system. Resource utilization efficiency is also much upgraded high by the introduction of advanced fuel cycles with a significant high share of fast reactors (i.e. only a half amount of uranium can be consumed in case of introduction of breakeven type FR compared to once-through fuel cycle case.)
Experience in Operating Mobile Solidification Plant for BNFL Environmental Services
Authors: Porter Jim
Published: March 2009

UK power stations have generated wet radioactive wastes, principally from operation of treatment plants for cooling pond water and liquid effluents. These include ion exchange resins, filter backwash sludges, flocs, pond sludges, filter aids, and miscellaneous oily sludges. To treat these wastes, it was concluded that mobile plants offered significant benefits compared with the alternative of constructing fixed installations. NSG Environmental Ltd designed and built a Mobile LLW Solidification Plant, which we have operated on behalf of BNFL Environmental Services and its predecessors for over twelve years. Since commencing active operations in 1991 the plant has successfully performed 28 campaigns on 13 nuclearlicensed sites. A total of nearly 3,000 drums of active waste have been processed during those campaigns. There have been no failures to solidify wastes, no excessive doses to operators and no transport incidents.
NUMO’s Open Solicitation of Volunteer Municipalities for a Potential Disposal Site
Authors: Kitayama Kazumi
Published: March 2009

In the year 2000, the Japanese geological disposal program for high-level radioactive waste (HLW) moved from the phase of generic research and development into the phase of implementation. Following legislation entitled the “Specified Radioactive Waste Final Disposal Act” (hereafter “the Act”), the Nuclear Waste Management Organization of Japan (NUMO) was established as the implementing organization in October 2000. The assigned activities of NUMO include repository site selection, developing relevant license applications and construction, operation and closure of the repository. To initiate the first stage, NUMO has chosen an “open solicitation” approach for finding candidate sites in the belief that the support of local communities is essential to the success of this highly public, long-term project extending over more than a century. Based on this concept, NUMO announced the start of open solication for volunteer municipalities for selection of Preliminary Investigation Areas to the public on December 19, 2002. This paper describes NUMO’s open solicitation of volunteer municipalities for a potential disposal site.
Vitrification of HLW Produced by Uranium/Molybdenum Fuel Reprocessing in COGEMA’s Cold Crucible Melter
Authors: Quang R. Do , Petitjean V. , Hollebecque F. , Pinet O. , Flament T. , Prod’homme A.
Published: March 2009

The performance of the vitrification process currently used in the La Hague commercial reprocessing plants has been continuously improved during more than ten years of operation. In parallel COGEMA (industrial Operator), the French Atomic Energy Commission (CEA) and SGN (respectively COGEMA’s R&D provider and Engineering) have developed the cold crucible melter vitrification technology to obtain greater operating flexibility, increased plant availability and further reduction of secondary waste generated during operations. The cold crucible is a compact water-cooled melter in which the radioactive waste and the glass additives are melted by direct high frequency induction. The cooling of the melter produces a soldified glass layer that protects the melter’s inner wall from corrosion. Because the heat is transferred directly to the melt, high operating temperatures can be achieved with no impact on the melter itself. COGEMA plans to implement the cold crucible technology to vitrify high level liquid waste from reprocessed spent U-Mo-Sn-Al fuel (used in gas cooled reactor). The cold crucible was selected for the vitrification of this particularly hard-to-process waste stream because it could not be reasonably processed in the standard hot induction melters currently used at the La Hague vitrification facilities: the waste has a high molybdenum content which makes it very corrosive and also requires a special high temperature glass formulation to obtain sufficiently high waste loading factors (12% in molybednum). A special glass formulation has been developed by the CEA and has been qualified through lab and pilot testing to meet standard waste acceptance criteria for final disposal of the U-Mo waste. The process and the associated technologies have been also being qualified on a full-scale prototype at the CEA pilot facility in Marcoule. Engineering study has been integrated in parallel in order to take into account that the Cold Crucible should be installed remotely in one of the R7 vitrification cell. This paper will present the results obtained in the framework of these qualification programs.