Browse Topic: Nuclear energy

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System Safety for Vertical FlightF-0075-2019-147115/13/2019
The field called System Safety evolved to satisfy the demand for an organized approach to safety management of complex new aerospace systems being developed in the 1960s. As technology has advanced and complexity has increased, its application spread to aviation, rail transportation, weapons, nuclear power, medical devices, oil and gas production, and almost every area of life where complex systems could lead to events having high consequences. System Safety is often defined as the application of engineering and management principles, criteria, and techniques to achieve acceptable mishap risks within the constraints of operational effectiveness, time, and cost throughout all phases of the system life cycle. The International System Safety Society states that for almost any system, product, or service, the most effective means of limiting product liability and accident risks is to implement an organized system safety function beginning in the conceptual design phase, and continuing through to its development, fabrication, testing, production, use, and ultimate disposal.
Hewitt, John
The Review of Present and Future Energy Structure in China2019-01-06124/2/2019
Both the economy and energy demand increase rapidly in China. The government is facing severe problems from energy security, carbon emissions and environmental issues. The past trends and future plans of energy will have great influence on the transportation, construction and industry development. This paper summarizes the present and future energy structure in China. Conventional fossil energy, nuclear energy and renewable energy are all included. Electricity will account for more proportion in total energy consumption in the future, and the structure of electricity will be cleaner. That will promote the development of electric vehicles and the transformation of China’s automotive industry. The optimization of energy structure will accelerate the low-carbon development in China. China’s energy development will enter a new stage from the expansion of total quantity to the upgrading of quality and efficiency. In order to realize the Paris Climate Agreement, China must steadily control the total energy consumption. The energy consumption in China will be in a period of slow growth. Constantly optimizing the energy structure and promoting renewable energy will both ease the energy crisis and ensure that China’s goal of reducing CO2 emissions can be achieved. China will further strengthen international cooperation in energy projects in the future. Through the cooperation, the energy structure in China will be further optimized. The efficient technology research & development and infrastructure construction of energy storage and remote power transfer will be vital to energy development. It will have influence on the future promotion of various renewable energy resources. The government will propel the reform of the oil and gas industry, and gradually open the market to the social capital. This measure will emphasize the role of the market in the energy development.
Liu, Feiqi, Zhao, Fuquan, Hao, Han, Liu, Zongwei
Wearable “Microbrewery” Monitors Radiation ExposureTBMG-336261/1/2019
Radiology workers are regularly exposed to low doses of radiation when they obtain patient imagery such as X-rays. While protective gear largely keeps workers within a safe range of radiation exposure, absorbing a little bit is still inevitable. Radiation doses creeping above regulated guidelines pose risk for developing conditions such as cancer, cataracts, skin irritation, or thyroid disease.
Facility Focus: Ames LaboratoryTBMG-3340812/1/2018
Ames Laboratory is a government-owned, contractor-operated national laboratory of the U.S. Department of Energy (DOE), operated by and located on the campus of Iowa State University in Ames, IA. For more than 70 years, Ames Laboratory has successfully partnered with Iowa State University and is unique among the DOE laboratories in that it is physically located on the campus of a major research university.
The Distributed Simulation of Intelligent Terrain Exploration2018-01-191510/30/2018
In this study we consider the coordinated exploration of an unfamiliar Martian landscape by a swarm of small autonomous rovers, called Swarmies, simulated in a distributed setting. With a sustainable program of return missions to and from Mars in mind, the goal of said exploration is to efficiently prospect the terrain for water meant to be gathered and then utilized in the production of rocket fuel. The rovers are tasked with relaying relevant data to a home base that is responsible for maintaining a mining schedule for an arbitrarily large group of rovers extracting water-rich regolith. For this reason, it is crucial that the participants maintain a wireless connection with one another and with the base throughout the entire process. We describe the architecture of our simulation which is composed of HLA-compliant components that are visualized via the Distributed Observer Network tool developed by NASA. Additionally, a well-known terrain exploration algorithm, which takes the constraint of a mobile ad hoc network into account, is summarized and then extended by using a trainable genetic algorithm to determine the movement of the robotic swarm at every time step of the simulation. The integration of this extended algorithm into the distributed simulation is discussed and the empirical results of a comparison between the original and extended versions are given. Our results suggest that the genetic algorithm serves as a useful aid in the simulation of coordinated exploration and provides a layer of flexibility, offered by the trainable parameters its fitness function depends upon, that allows for the introduction of new constraints while maintaining compatibility with dynamic shifts in priority.
Anekstein, David, Cornett, Jacob, Guerrero, Marc, Williamson, Cory
Idaho National LaboratoryTBMG-3310510/1/2018
In 1951, the first nuclear reactor in Idaho was built, starting a legacy at what is now Idaho National Laboratory (INL). INL is the site where 52 pioneering nuclear reactors were designed and constructed, including the first reactor to generate usable amounts of electricity. It was here that nuclear-generated electricity first powered an American community.
Integrated Multiphysics and Advanced DiagnosticsTBMG-328329/1/2018
The objective of this effort was to design, fabricate, integrate, and fly a nuclear thermal rocket without having to build massive ground test facilities. Furthermore, this nuclear rocket would be inspected internally without having to disassemble it. Another aim here was to predict the reliability for a 15-to-20-year lifetime for a surface nuclear power plant essential for supplying power to explorers on the Moon or Mars, all without having to build and test a full-scale reactor. If the performance of these systems could be predicted, one could establish the impact of manufacturing tolerances on the operations of these systems.
Assessment of Non-Traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear ActivitiesTBMG-273848/1/2017
The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources.
Assessment of Non-Traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities17AERP08_106/1/2017
Technique can be used to distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Defense Threat Reduction Agency, Fort Belvoir, Virginia The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources. There are many sources for radionuclides in our environment. These include natural sources, the commercial nuclear industry, nuclear weapons, the medical industry, and other sources. Often times, the source of the radionuclide may be determined through just identification of the radionuclide. If radionuclides are produced through different sources, the identification of the source is complex. In order to ascertain a specific source for attribution, radionuclide ratios are often employed.
Fluid Harmonic AbsorberTBMG-251818/1/2016
NASA Marshall Space Flight Center’s Fluid Structure Coupling (FSC) technology is a highly efficient and passive method to control the way fluids and structures communicate and dictate the behavior of a system. This technology has the demonstrated potential to mitigate a multitude of different types of vibration issues, and can be applied anywhere internal or external fluids interact with physical structures. For example, in a multistory building, water from a rooftop tank or swimming pool could be used to mitigate seismic or wind-induced vibration by simply adding an FSC device that controls the way the building engages the water.
Helicopter Operation at Fukushima Nuclear DisasterF-0072-2016-115085/17/2016
At 14:46 JST on March 11, 2011, a massive earthquake hit the northeastern coast of Japan. The magnitude of the earthquake was 9.0 (Mw). It was the most powerful earthquake ever recorded in Japanese history. The earthquake triggered a deadly tsunami and swept away thousands of houses and lives. At the same time, the Fukushima Dai-ichi (No1) nuclear power plant was struck by the tsunami and the reactor took serious damage. This caused reactors to have a core meltdown and explode. There had been a radiation leak in the nuclear power plant. On March 15, the Japanese government set the restricted area within 30 km from the Fukushima nuclear power plant due to the radiation leakage. On March 17, two Japan Self Defense Force (JSDF) CH-47J helicopters dropped water to cool the failing reactor. The mission was successful, and the radiation around the reactor was gradually decreased, allowing for further operations. On April 14, one month after the disaster, the Japanese government requested the dispatchment of the Japan Coast Guard (JCG) for a search and rescue mission within the restricted area. This was the first search and rescue mission held at sea within a radioactive-contaminated environment in Japan, for which nine patrol boats, two airplanes, and three helicopters were sent for the mission. This paper describes the general outline about the cooling, thermo-monitoring, and the search and rescue missions as well as the equipment used, maximum permissible dose of radiation, and the mission environment. Then it compares this data with the helicopter operations during the Chernobyl accident. The purpose of this paper is to expand readers' knowledge about helicopter operations during nuclear disasters with the hopes for it to be a useful material for future missions. The story of this paper is based on the author's experience as a dispatched Japanese Coast Guard helicopter pilot.
Sagane, Hajime
Actuation Technique for Miniature Robots Developed Using Multiphysics SimulationTBMG-2309010/1/2015
Minimally invasive surgery depends on small, flexible tools with reliable actuation and consistent performance. Robotic devices have entered the operating room as assistants to procedures requiring hours of standing on the part of the surgeon. But many robotic surgery devices are expensive, bulky, and exhausting to operate. Christine Rotinat, researcher at the Systems and Technologies Integration Laboratory of the French Atomic Energy and Alternative Energies Commission (CEA LIST) Gif-sur-Yvette, France, has sought to create an alternative. By making miniature robotic manipulators easier to build and operate, she hopes to offer a less expensive actuator than those currently used in surgical devices.
Optically Modulated Miniature MagnetometerTBMG-225668/1/2015
The optically modulated miniature magnetometer (OMMM) is intended to replace two separate instruments (each with their respective mass and power allotments) that are commonly needed together for scientific studies of magnetic fields — a triaxial fluxgate vector magnetometer and an optically pumped alkali vapor scalar magnetometer. For all vector instruments, the scalar data is necessary for calibrating the vector data.
Brainwave Monitoring Software Improves Distracted MindsTBMG-3609512/1/2014
Imagine moving an object using only your mind. Software company Unique Logic’s Time on Task exercise makes that feat possible, at least on a computer screen. The game, which is designed to teach people how to sustain their attention in order to complete tasks, involves getting a forklift operator to transport a stack of crates from the ground onto the back of a big rig. It doesn’t seem like a particularly interesting plot, except for the fact that, instead of using a remote control to dictate the action, you’re using your concentration—measured by sensors that detect patterns of brainwave activity—to induce the operator to complete the job.
Integrated Reliability and Safety Education Program2013-01-21219/17/2013
The safe operation of technical systems is a mandatory basic requirement for the entire industry. However, there are specific industries where the safety of operation is critical and is considered as a required characteristic. These types of industries include the aerospace, military, civil aviation, nuclear power, as well as chemical and automotive industries. Safety is everyone's responsibility but engineering plays the most important role in the course of achieving a safe product operation. There are two specific phases of the product life cycle where the safety characteristics should be addressed by engineering activities: the design and development and operation phases. Modern engineering education is oriented to provide future engineers with a sufficient background to be able to Conceive-Design-Implement-Operate. The emphasis of this approach is on the achievement of dual objectives; first to teach the students a large spectrum of technologies and second to develop their personal and interpersonal capabilities in order for them to be able to build complex engineering systems. A university-level engineering curriculum very rarely includes topics related to safety and security of technical systems. Engineering programs mainly focus on the product performance knowledge domains and the safety of a product is covered in a somewhat underwhelming way. This paper provides an overview of selected university-level educational programs focusing on the topic of technical systems' safety. The synopsis of the educational safety initiative is described as a combination of university and industry integrated approach to enhance the safety knowledge and to create a safety-oriented culture for the new generation of engineers. A few examples of implemented programs from the aerospace industry are provided.
Klim, Zdzislaw H., Skorek, Adam
Radioisotope System Keeps Mars Rover MovingTBMG-166146/1/2013
The instruments aboard NASA’s Mars Science Laboratory “Curiosity” rover receive their power from a radioisotope system assembled and tested at Idaho National Laboratory. The Multi- Mission Radioisotope Thermoelectric Generator is a “space battery” that can reliably power a deep space mission for many years.
Turbomachinery Solutions for Green and Renewable EnergyTBMG-164515/1/2013
For more than two decades, nearly all renewable energy endeavors have incorporated the latest advances in turbomachinery design and turbomachinery manufacturing technology in an evolving effort to achieve and even surpass the economics of utility scale. Even mature turbomachines continue to be optimized for increments of better performance, efficiency, and energy conservation.
Determining Key Isotopic Ratios In The FieldTBMG-1517411/1/2012
On August 6th, 2012 the automatic Mars Science Laboratory rover named Curiosity landed on Mars. One of the scientific instruments on board is ChemCam, which has a pulsed laser capable of ablating a focused spot on a remote sample to create a glowing plasma plume of target material. Light from plasma is collected by rover’s telescope on a mast, and the optical spectra are then analyzed by an internal spectrometer. ChemCam can take thousands of spectra per day from a distance of about 7 meters, thus making chemical analyses on the surface of Mars with unprecedented speed. Operationally, the ChemCam data facilitates decisions of where the rover should be driven.
Project Ciclar: A Light, Electric Powered Vehicle for Selective Waste Collection2012-36-020610/2/2012
In response to the increasing scarcity of oil reserves and the negative impact carbon emissions have on the environment, clean technologies and renewable energy must take priority in research. Project Ciclar combines clean technology with sustainability to create an environmentally friendly vehicle for selective waste collection. Unlike conventional waste collection vehicles in Brazil, the Electric-powered Lightweight vehicle for selective waste Collection (ELC) is powered entirely by electrical and solar energy, thereby ensuring zero emissions. Even though ELC is electric, a major concern of the project was to produce a vehicle that would be as energy efficient as possible. By employing an electric motor, ELC reduces the per kilometer cost of operation by approximately 50% in comparison to petroleum-based fueled engines. With the proper infrastructure, refueling vehicles with electricity rather than gas is both less expensive and more convenient, which should eventually not only encourage but also ease the transition from petroleum-fueled vehicles to electric. This article shows how it is possible to build a low cost, environmentally friendly vehicle. It explains the environmental impact of different energy sources, specifically petroleum. It compares various types of electric motors and combustion engines to evaluate gas emissions and efficiency. Finally, it compares the effectiveness of a solar panel versus an alternator.
Dodge, Eduardo Jose Ferreira, Orrico, Marcos V. M., Souza, Pedro Vinicius Guimaraes, Shayani, Rafael Amaral, Viana, Dianne Magalhaes
Onboard Sensor Data Qualification in Human-Rated Launch VehiclesTBMG-1483510/1/2012
The avionics system software for human-rated launch vehicles requires an implementation approach that is robust to failures, especially the failure of sensors used to monitor vehicle conditions that might result in an abort determination. Sensor measurements provide the basis for operational decisions on human-rated launch vehicles. This data is often used to assess the health of system or subsystem components, to identify failures, and to take corrective action. An incorrect conclusion and/or response may result if the sensor itself provides faulty data, or if the data provided by the sensor has been corrupted. Operational decisions based on faulty sensor data have the potential to be catastrophic, resulting in loss of mission or loss of crew. To prevent these later situations from occurring, a Modular Architecture and Generalized Methodology for Sensor Data Qualification in Human-rated Launch Vehicles has been developed.
Silicon Block Inspection with SWIR ImagingTBMG-1223411/29/2011
In a world where oil production is declining, and where both nuclear energy plant and spent-fuel storage safety have proven to be inadequate, there is increased pressure on solar power generation to fill the gap. In response to the increased demands for energy, the photovoltaic manufacturing industry has focused on two primary objectives: driving down the cost of solar panels and increasing panel efficiency.
Energy Storage: Regenerative Fuel Cell Systems for Space Exploration2011-01-262410/18/2011
Future exploration missions, including human missions to the Moon and Mars, are expected to have increasingly demanding operational requirements. Generating electrical power, and also maintaining a specific thermal environment, are both critical capabilities for any mission. In the case of exploration, both a wide range of mission types (robotic, human, ISRU etc.) and a variety of environments exist: from interplanetary space, to the shadow of a lunar crater, to the attenuated and red-shifted lighting on the Martian surface, power requirements must be met. This objective could be met with different technologies. The choice is dictated by the operating conditions and the different types of mission. TAS-I is historically mainly involved in missions related to the space exploration with the presence of astronauts. A typical example is the exploration of the Moon with the installation on the Moon surface of a base inclusive of pressurized habitats and rovers. For this kind of application it has been identified as potential candidate the utilization of Regenerative Fuel Cell (RFC) System. The RFC is an electrochemical system that collects and stores solar energy during the day then releases that energy at night, thus making energy available all 24 hours. The process absorbs power from an external source (typically solar panels) and stores energy through the electrolysis process splitting water in Hydrogen and Oxygen. The energy is physically stored inside the reactant tanks, one for Hydrogen and one for Oxygen. When the energy is required the reactants are recombined inside a fuel cell, producing electric power, thermal power and water which is re-used during the next cycle. The research is being carried out by Thales Alenia Space Italy, in the framework of a regional program called STEPS. Thales Alenia Space has been supported in this activity by Politecnico di Torino and Hysytech.TAS-I with the associated team, has developed a 10 kW breadboard of a RFC System and in parallel a preliminary concept of a RFCS for a Pressurized Lunar Rover. The preliminary results on this subject are used to perform a reasoned comparison between this innovative technology w.r.t. Lithium Ion batteries technology.
Ferrari, Giorgio Luigi, Pelle, Stewart, Antonini, Massimiliano, Cabrera, Manuel, Armandi, Marco, Bonelli, Barbara, Zanzottera, Cristina
Topical Compositions and Glove for Protection and Shielding Against Radiation ExposureTBMG-83939/1/2010
Over the past several decades, there has been a proliferation of medical diagnostic and treatment devices that involve the use of X-rays, beta rays, gamma rays, and radioactive isotopes. In addition, there has been recent concern regarding possible radiation exposure from nuclear weapons and terrorist attacks on nuclear facilities. Thus, there is a need for devices that can protect areas of the body that may be exposed to damaging radiation without hindering the user’s dexterity or loss of touch sensation.
Integrated Safety Management System2009-01-317111/10/2009
The Safety Management System requires a structured Risk Management Process to be effective. In the technical fields where numerous potentially catastrophic risks exist, processes and procedures need to account not only for the hardware random failures but also of human errors. The technology has progressed to the point where the predominant safety risks are not so much the machine failures but that of the human interaction. Accidents are rarely the result of a single cause but of a number of latent contributing factors that when combined result in the accident. In the Aerospace industry, the operational risk to the fleet is assessed by the manufacturer and the operator independently and is used in safety and/or regulatory decision-making. For the manufacturer, the risk assessment is a philosophy whereby risk of a potential or actual occurrence is evaluated in comparison to the event analyzed in the system safety assessment or structural analysis performed for certification of the product. The resulting safety decision-making process involves integration of the probabilistic risk assessment, deterministic and severity perception elements such that the decisions made leads to corrective or preventative actions. The evaluations of the human factors elements are subjectively assessed based on individual experience based criteria and are difficult to integrate into the safety decision. The risk assessment is viewed as the process that records all these factors as the basis for the safety decision and prioritization of the corrective actions. In the Nuclear industry a risk-informed approach to safety and/or regulatory decision-making represents a philosophy whereby risk insights are considered together with other factors, including good engineering practice and experience, to establish the design requirements and operational issues commensurate with their importance to public health and safety. A standard risk-based approach to safety and/or regulatory decision-making is one in which a decision is based solely on the numerical results of a risk assessment. Quantitative risk analyses are important inputs to decision making, but they do not constitute an adequate or sufficient base of information for addressing the complex issues that face the nuclear power industry. For that reason such analyses are only one of the many contributing inputs to a comprehensive risk-informed decision making process. Risk-informed decision making involves integration of probabilistic, deterministic and non-quantifiable elements such that, overall, the decisions made lead to a resolution of the issue being considered that is commensurate with its risk-significance and is better to that likely to be reached if any approach is used in isolation. This paper intends to compare the Risk Management methodologies and procedures used in the Aerospace and Nuclear industries to highlight similarities and differences. The learning from these differences may then identify potential improvements to either methodology.
Kavoliunas, Michael, Klim, Zdzislaw H., Komljenovic, Dragan
Experimental Study of Coupled Longitudinal and Transverse Vibration of Automotive Belts2009-01-11984/20/2009
There are many studies on vibrations of moving belts originated from automotive belt drives. However, they mainly consider nonlinear effect of the transversal vibration of the belt under transversal excitation without considering the coupling effect between the transversal and longitudinal vibrations under longitudinal excitation. This paper presents the experimental methodology and the experiments results analysis on a stationary belt excited longitudinally only. It is found that the induced transversal vibration appears as a stable beating phenomenon due to internal resonance from the periodic energy transfer between the coupled longitudinal excitation and the transversal vibration, manifested as a standing wave.
Scurtu, Petru Razvan, Clark, Mike, Zu, Jean W.
Grooved Fuel Rings for Nuclear Thermal Rocket EnginesTBMG-35452/1/2009
An alternative design concept for nuclear thermal rocket engines for interplanetary spacecraft calls for the use of grooved-ring fuel elements. Beyond spacecraft rocket engines, this concept also has potential for the design of terrestrial and spacecraft nuclear electric-power plants.
Adopting Aerospace Development and Verification Standards for SoftwareTBMG-620911/1/2008
An ever-increasing reliance on software control has meant that many companies from non-aerospace business sectors (automotive, nuclear power, MRI scanners, financial systems) that do not have a traditional requirement for sophisticated software development processes now find themselves compelled to undertake safety-critical and safety-related analysis and testing. With the need for increased software quality across different industries, a tendency has emerged for companies to look outside their own market sector for best practice approaches, techniques or standards. Examples of such industry crossover have been seen in the automotive and avionics industries with the adoption of elements of the DO-178B standard by the former and a similar adoption of the Motor Industry Software Reliability Association (MISRA) standards by the latter.
Green Energy for the BattlefieldTBMG-29337/1/2008
The amount of energy the United States consumes increases every year and this growth in energy consumption outpaces energy production. To fill this gap, the U.S. imports 35% of its energy. More importantly, the U.S. imports over 60% of its total oil consumption. Added to this, 70% of this energy is from non-renewable sources.
Improved Operation of CO 2 Separator for Preventing Increases in CO 2 Concentration of Air in the Habitation Room during Closed Habitation Experiments2007-01-30977/9/2007
The main objective of the activities of the Closed Ecology Experiment Facilities (CEEF) is to construct a mathematical model to predict the transfer of radiocarbon (14C) released from a nuclear fuel reprocessing plant in the village of Rokkasho into the local ecosystem. For this purpose, an artificial ecosystem, including crops, domestic animals, and human inhabitants, needs to be maintained in the CEEF for several months. As a preparatory study, two-week habitation experiments using the CEEF were planned in 2006. In the first habitation experiment, a CO2 separator was continuously operated with a cycle of 60-minute adsorption and 60-minute desorption periods in order to remove excess CO2 from the habitation room, and the maximum CO2 concentration of air in this room slightly exceeded 5000 ppm, which was identical to the maximum 8-hour exposure permitted for industrial settings. In the second habitation experiment, therefore, the duration of both the adsorption and desorption periods for the operation of the CO2 separator was shortened to 54 minutes in order to increase the cumulative number of adsorption periods per day. The approx. 10% increase in the cumulative number of adsorption periods per day resulted in a decrease of approx. 10% in the maximum CO2 concentration of air in the habitation room during the second habitation experiment. This result demonstrated how the improved operation of the CO2 separator contributed to maintaining the CO2 concentration of air in the habitation room below the maximum 8-hour exposure permitted for industrial settings.
Tani, Takashi, Tsuga, Shouichi, Tako, Yasuhiro
Validation Studies of the GRNTRN Code for Radiation Transport2007-01-31187/9/2007
To meet the challenge of future deep space programs an accurate and efficient engineering code for analyzing the shielding requirements against high-energy galactic heavy radiations is needed. Such engineering design codes require establishing validation processes using laboratory ion beams and space flight measurements in realistic geometries. In consequence, a new version of the HZETRN code capable of simulating HZE ions with either laboratory or space boundary conditions is currently under development. The new code, GRNTRN, is based on a Green's function approach to the solution of Boltzmann's transport equation and like its predecessor is deterministic in nature. Code validation in the laboratory environment is addressed by showing that GRNTRN accurately predicts energy loss spectra as measured by solid-state detectors in ion beam experiments. In order to validate the code with space boundary conditions measured particle fluences are propagated through several thickness of shielding using both GRNTRN and the current version of HZETRN. The excellent agreement obtained indicates that GRNTRN accurately models the propagation of HZE ions in the space environment as well in laboratory settings and also provides verification of the HZETRN propagator.
Tweed, J., Walker, S. A., Wilson, J. W., Tripathi, R. K., Badavi, F. F., Miller, J., Zeitlin, C., Heilbronn, L. H.
Design Concept for a Nuclear Reactor-Powered Mars RoverTBMG-17965/1/2007
A report presents a design concept for an instrumented robotic vehicle (rover) to be used on a future mission of exploration of the planet Mars. The design incorporates a nuclear fission power system to provide long range, long life, and high power capabilities unachievable through the use of alternative solar or radioisotope power systems. The concept described in the report draws on previous rover designs developed for the 2009 Mars Science laboratory (MSL) mission to minimize the need for new technology developments.
Nuclear Reactor Cooling Valve Design Optimized With FEATBMG-128212/1/2006
Atomic Energy of Canada, Ltd., a subcontractor of Societatea Nationala Nucleoelectrica S.A. (SNN) of Romania, contracted Badger Meter to model, test, and produce a set of precision valves for Cernavoda Unit 2, the second nuclear power plant in Cernavoda, Romania. The main concern for the construction and operation of the valves was their survivability and continued functioning after enduring an earthquake. In nuclear power plants, such valves control the cooling of the nuclear reactors where continued flow of water around the nuclear core is essential for safety. After the earthquake that precipitated the eruption of Mt. Saint Helens in 1980, testing criteria for valves routinely has included their capability to ensure the safe functioning of the reactor after seismic events, at least in terms of cooling capacity.
Design and Selection Considerations for High-Temperature Aerospace AccelerometersTBMG-628/1/2006
Accelerometers used for shock and vibration measurement in extreme environments require special consideration in the design and manufacturing process. Certain unique applications can require the same accelerometer to function from -54 to 649 °C (-65 to 1,200 ° F). This might include such applications as vibration measurement on gas turbine engines, in flight, or in test cells; rocket motor vibration measurements; and thruster vibration. These accelerometers also may need to function in nuclear radiation environments, and possibly in a combination of temperature extremes and radiation. This might include nuclear power generation or space vehicle applications. Materials and construction must then be selected not only to enhance high temperature performance, but also to allow operation in the presence of gamma and neutron radiation
Standardized Radiation Shield Design Method: 2005 HZETRN2006-01-21097/17/2006
Research committed by the Langley Research Center through 1995 resulting in the HZETRN code provides the current basis for shield design methods according to NASA STD-3000 (2005). With this new prominence, the database, basic numerical procedures, and algorithms are being re-examined with new methods of verification and validation being implemented to capture a well defined algorithm for engineering design processes to be used in this early development phase of the Bush initiative. This process provides the methodology to transform the 1995 HZETRN research code into the 2005 HZETRN engineering code to be available for these early design processes. In this paper, we will review the basic derivations including new corrections to the codes to insure improved numerical stability and provide benchmarks for code verification.
Wilson, J. W., Tripathi, R. K., Badavi, F. F., Cucinotta, F. A.
An Improved Green’s Function Code for HZE Ion Transport2006-01-21477/17/2006
A new Green’s function code (GRNTRN) capable of simulating HZE ions with either laboratory or space boundary conditions is currently under development. The computational model consists of combinations of physical perturbation expansions based on the scales of atomic interaction, multiple scattering, and nuclear reactive processes with use of the Neumann-asymptotic expansions with non-perturbative corrections. The code contains energy loss due to straggling, nuclear attenuation, nuclear fragmentation with energy dispersion and downshifts. Recent publications have focused on code validation in the laboratory environment and have shown that the code predicts energy loss spectra accurately as measured by solid-state detectors in ion beam experiments. In this paper emphasis is placed on code validation with space boundary conditions. Measured particle fluences associated with the 1977 solar minimum are propagated through several thickness of Aluminum using both GRNTRN and current version of HZETRN. The excellent agreement obtained indicates that GRNTRN accurately models the propagation of HZE ions in the space environment as well as in laboratory settings and provides verification of the HZETRN propagator in which straggling and nuclear energy downshift and dispersion are neglected.
Tweed, J., Walker, S. A., Wilson, J. W., Tripathi, R. K., Cucinotta, F. A., Badavi, F. F.
Dielectric Heaters for Testing Spacecraft Nuclear ReactorsTBMG-4052/1/2006
Like the electrical-resistance heaters used heretofore for such testing, the dielectric heaters would be inserted in the reactors in place of nuclear fuel rods. A typical heater according to the proposal would consist of a rod of lossy dielectric material sized and shaped like a fuel rod and containing an electrically conductive rod along its center line. Exploiting the dielectric loss mechanism that is usually considered a nuisance in other applications, an RF signal, typically at a frequency =50 MHz and an amplitude between 2 and 5 kV, would be applied to the central conductor to heat the dielectric material. The main advantage of the proposal is that the wiring needed for the RF dielectric heating would be simpler and easier to fabricate than is the wiring needed for resistance heating. In some applications, it might be possible to eliminate all heater wiring and, instead, beam the RF heating power into the dielectric rods from external antennas.
Some New Results in the Green’s Function Method for Ion Beam Transport2004-01-23227/19/2004
The development of a Green’s function approach to ion transport greatly facilitates the modeling of laboratory radiation environments and allows for the direct testing of transport approximations of material transmission properties. Using this approach radiation investigators at the NASA Langley Research Center have established that simple solutions can be found for HZE ions by ignoring nuclear energy downshifts and dispersion. Such solutions were found to be supported by experimental evidence with HZE ion beams when multiple scattering was added. Lacking from the prior solutions were range and energy straggling and energy downshift and dispersion associated with nuclear events. In a more recent publication it was shown how these effects can be incorporated into the multiple fragmentation perturbation series. Analytical approximations for the first two perturbation terms were presented and the third term was evaluated numerically. We now exhibit an analytical approximation for the third perturbation term and then demonstrate the accuracy of our results.
Walker, S. A., Tweed, J., Wilson, J. W., Tripathi, R. K.
Estimation of Water Circulation Based on Experimental Results from Sequential Crop Cultivation, Closed Goat Breeding and Simulated Habitation Using CEEF2004-01-23497/19/2004
Closed habitation experiments are to be carried out using Closed Ecology Experiment Facilities (CEEF) from FY2005 to FY2009. The last target of duration of closed habitation is four months. Preliminary study and testing have been conducted in order to carry out the closed habitation experiments. The CEEF has three closed plantation chambers (PC-A, B and C) with artificial lighting solely having each cultivation area of 30 m2 and a closed plantation chamber (PC-F) with both natural lighting and supplemental artificial lighting having a 60-m2 cultivation area. A ‘stable’ period of sequential crop cultivation was maintained for four weeks in a trial experiment conducted in FY2003 using the Plantation Module (PM), in which rice, soybean and crops including rice sapling, soybean sapling, soybean, peanuts and safflower were cultivated in PC-A, PC-B, PC-C and PC-F, respectively. Amount of total clean water input to PM was 741 L day−1 on the average for the period. That includes 645 L day−1 of replenishing water supplied to plant cultivation beds and 96 L day−1 of humidifying water. Amounts of condensate and water in harvested biomass from the PM were 681 and 8.4 L day−1, respectively. In addition to them, 1311 L day−1 of nutrient solution in the plant cultivation beds was exchanged. The waste nutrient solution was processed through the Reverse Osmosis membrane (RO) system.1245 L day−1 of water having solute concentration of less than 5% of that of the waste nutrient solution was recovered. Both condensate sterilized through Ultra Violet ray exposure system and water processed through the RO were used for making of new nutrient solution. Amounts of water in food, drinking water and other water consumption including washing, shower and sanitary for two persons during a simulated closed habitation trial lasting five days conducted in FY2003 were 2.9, 1.0 and 112 L day−1, respectively. Amount of water in rice straw as feeding, drinking water and cage washing water for two Shiba-goats each having 25-kg body weight during closed breeding experiment conducted in FY2003 were estimated as 0.1, 5.7 and 0.4 L day−1, respectively. Using above data and estimation result, water flow in the CEEF material circulation system was estimated.
Tako, Yasuhiro, Tsuga, Shou-ichi, Arai, Ryuji, Tani, Takashi, Honda, Go, Nitta, Keiji
AIN-Based Packaging for SiC High-Temperature ElectronicsTBMG-6863/1/2004
Packaging made primarily of aluminum nitride has been developed to enclose silicon carbide-based integrated circuits (ICs), including circuits containing SiC-based power diodes, that are capable of operation under conditions more severe than can be withstood by silicon-based integrated circuits. A major objective of this development was to enable packaged SiC electronic circuits to operate continuously at temperatures up to 500 °C. AlN-packaged SiC electronic circuits have commercial potential for incorporation into high-power electronic equipment and into sensors that must withstand high temperatures and/or high pressures in diverse applications that include exploration in outer space, well logging, and monitoring of nuclear power systems. This packaging embodies concepts drawn from flip-chip packaging of silicon-based integrated circuits. One or more SiC-based circuit chips are mounted on an aluminum nitride package substrate or sandwiched between two such substrates. Intimate electrical connections between metal conductors on the chip(s) and the metal conductors on external circuits are made by direct bonding to interconnections on the package substrate(s) and/or by use of holes through the package substrate(s). This approach eliminates the need for wire bonds, which have been the most vulnerable links in conventional electronic circuitry in hostile environments. Moreover, the elimination of wire bonds makes it possible to pack chips more densely than was previously possible.
Aerospace Engineering 2003-12-01AERODEC0312/1/2003
Telling the future Technology and the environment, BWBs and UAVs, and nuclear power may be the forces for the future of aerospace engineering. Top technologies for 2003 "Aerospace Engineering's" annual review of the technologies chosen by its editors and readers to be the most significant. Supporting aerospace design The proper use of COTS technologies can change the range of new processes and products in the electrical sector. American attack UAVs- Part II The second article in a two-part series of a perspective on more than 100 years of unmanned flight details some of the major developments in the use of unmanned aerial vehicles for combat.
Lightning Protection: Experimental Approach and Solutions for Large Sensitive Systems - Example of a Nuclear Power Plant -2001-01-29229/11/2001
This document describes the unclassified part of the lightning protection studies for a video control system. The study was held during September 1994 at Cruas Nuclear Power Plant (F-07). Positive improvements were seen immediately and long term benefits have been reinforced by continued protection. The studies were conducted with a new EMC (Electromagnetic Compatibility) concept: “Zero Method”. This concept uses an accessible and easy process to control the industrial electromagnetic interference from radio, cellular phones and lightning effects. The adopted solutions improve personnel and facility safety and provide a cost effective solution.
Soleil, Daniel, Alcaras, Alain
Map Reconstruction in the Indoor Environment for the Purpose of Autonomous Vehicle Using Laser Radar2001-01-08063/5/2001
This paper proposes how to develop an autonomous vehicle for factory and/or storehouse use. Where the geometric arrangement changes frequently due to the turnover of the cargo. We apply the sensor fusion technique by use of the Omni directional image sensor and laser radar generate the map of such situations. We propose a new update algorithm called SMT (Shift Matching Transform) that obtains region segments with trusted semi-real-time geometric map. We demonstrate how to determined the absolute position of the vehicle by the position information of arbitrary wall. Experimental results on the corridor, Shows the semi-real-time map reconstruction with enough validity.
Kobayashi, Kazuyuki, Sugishita, Shigenori, Watanabe, Kajiro
Circuit Detects Pyrolysis of Polyimide Insulation on WiresTBMG-2983812/1/1999
An electronic circuit has been designed as a prototype of a device that determines whether critical electrical systems have been compromised because of pyrolysis of polyimide-insulated wires. This circuit can be modified to prevent further pyrolysis and to check for indications of pyrolysis for a wide variety of load resistances and power supplies. Circuits like this one could be beneficial in spacecraft, in military and commercial aircraft, and in the nuclear power industry where polyimide-insulated wires are used.
Impact of Lightning Strikes on Nuclear Power Generating Stations1999-01-25788/2/1999
Electrical transients initiated by direct or indirect lightning strikes have caused reactor trips or misoperation of the equipment in nuclear power generating stations. The effects of lightning strikes on reactor trips or misoperation of the equipment were reviewed for the period 1984 through 1998. Based upon the review, it was found that in a number of cases, the overvoltage protection devices for the control rod drive system had operated due to the lightning strikes. There were also cases where lightning strikes had partially damaged the main/startup transformers, tripped the switchyard breakers or tripped the transmission lines and, thereby, impacted the availability of the required stable offsite power sources to the nuclear power generating stations. Since solid state circuitry designs including the digital instrumentation and control designs are being increasingly utilized in the reactor protection system and other systems, the chances of misoperation of low voltage equipment due to lightning strikes have increased. The low voltage circuitry may be more vulnerable now because of the integrated protection and microprocessor-based systems being used in the Simplified Passive Advanced Light Water Reactors which will be built into the next millennium.*
Trehan, Narinder K.
Lifetimes of AMTEC Electrodes: Rhodium-Tungsten and Titanium Nitride1999-01-27048/2/1999
The lifetime of an AMTEC electrode is predicted from the rate of grain growth in the electrode. The rate of growth depends on several physical characteristics of each material, including the rate of diffusion of the material on itself. Grain growth rates for rhodium-tungsten and titanium nitride electrodes have been determined, and have been used to predict operating lifetimes of AMTEC electrodes. For lifetimes of 10 years or more, RhxW electrodes may be used at any operating temperature supportable by the electrolyte. TiN electrodes may be used in AMTEC cells only at operating temperatures under 1150 K.
Ryan, M. A., Shields, V. B., Cortez, R. H., Lara, L., Homer, M. L., Williams, R. M.
Impedance Measurements of PX-Series AMTEC Cells1999-01-27068/2/1999
Initial impedance measurements of multi-BASE tube AMTEC cells have been accomplished. These measurements were based on theoretical analyses performed by the Jet Propulsion Laboratory. Electrochemical parameters were derived from a plot of the apparent charge transfer resistance, Ract, as a function of the electrical potential across the beta’’ alumina solid electrolyte. These included the morphology factor, G, the exchange current Joo, and α, the transfer coefficient. The factor G was given a value of 50 as a result of the inability of present equipment to achieve 1.6 volts across a single electrolyte element. Average values for the temperature independent charge exchange factor, B, are also reported. These results were taken from cells with as few as 3300 hours to as many as 12,000 hours of operation. The results show that if the assumed value for G is close to actual values, then Joo and α are much lower than those reported in previous literature, resulting in an increase in the charge transfer resistance.
Mayberry, Clay S., Radzykewycz, Dan
Optimized Hybrid LSS for Middle Electrical Rockets Space Missions9815307/13/1998
The combination of electrical engines with solar arrays, well shielded against radiation long-term LSS, and remote control robot-manipulator system named “Space Rover” is shown to be very promising tool for space exploration. General parameters of space ship based on already developed components, and parameters of flight are considered. Optimal structure of hybrid LSS for middle space range space missions is calculated. As optimization criteria minimum mass and maximum reliability are chosen. Combinations of biological and physical-chemical components are evaluated. It is shown that namely hybrid LSS provide the highest level of reliability and the best mass parameters.
Bartsev, S. I., Okhonin, V. A.
The Romance of EnginesR-1885/1/1997
This book examines the development of the engine from a historical perspective. Originally published in Japanese, The Romance of Engines' English translation offers readers insight into lessons learned throughout the engine's history. This book belongs on the bookshelves of all engine designers, engine enthusiasts, and automotive historians. Topics covered include: Newcomen's Steam Engine The Watt Steam Engine Internal Combustion Engine Nicolaus August Otto and His Engine Sadi Carnot and the Adiabatic Engine Radial Engines; Piston and Cylinder Problems Engine Life Problem of Cooling Engine Compartments Knocking; Energy Conservation Bugatti; Volkswagon Rolls Royce Packard Daimler-Benz DB601 Engine and more!
Suzuki, Takashi
Fine Pore Loop Heat Pipe Wick Structure Development9613195/1/1996
This paper describes the transfer of Russian fine pore sintered powder metal wick structure fabrication technology to the United States for use in the construction of U.S. made loop heat pipes (LHPs), capillary pumped loops (CPLs) and heat pipes. Sintered powder metal wick structures have been used in U.S. made heat pipes for over twenty-five years. The typical pore radii for these wick structures range from 10 to 100 microns. Use of a wick material with a pore radius less than 10 microns was limited due to the high pressure drop encountered when used in a standard heat pipe. Conversely, the Russian loop heat pipe is able to get around this high pressure drop constraint due to its unique evaporator design. Prior to the work presented in this paper, the U.S. concentrated on the development of wick structure materials above 10 microns which created a technology void with the advent of the LHP.
Gernert, Nelson J., Baldassarre, Gregg J.
Issues Associated with Operator Use of Automation9519859/1/1995
Automation is currently a topic of great interest. Part of the reason for this may be that problems associated with operator use of automation can be relatively subtle yet severe. When designing an automated system, it may not be obvious how the interactions between the operator, the system, and the environment may lead to errors. Consequently, those who design and certify flight deck systems should be aware of some of the issues associated with pilot use of automation. These include the potential for over reliance or under reliance on automation and the factors that can contribute to them, issues of pilot and automation authority, automation complexity, feedback, and transitions between automated and manual control. In this paper, we concentrate on how pilots make decisions to use or not use automation and the factors that can influence these decisions.
Riley, Victor
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