Toroidal plasmas created with negative magnetic shear in the core region offer advantages in terms of MHD stability properties. These plasmas, transiently created in several tokamaks, have exhibited high performance as measured by normalized stored energy and neutron production rates. A critical issue with extending the duration of these plasmas is the need to maintain the off-axis-peaked current distribution required to support the minimum in the safety factor q at large radii. We present equilibrium and transport simulations that explore the use of electron cyclotron heating and current drive to maintain this negative shear configuration. Using parameters consistent with DIII-D tokamak operation, we find that with sufficiently high injected power, it is possible to achieve steady-state conditions employing well aligned electron cyclotron and bootstrap current drive in fully non-inductively current-driven configurations.

We extend the argument of Gomis and Mehen for violation of unitarity in field theories with space-time noncommutativity to dipole field theories. In dipole field theories with a timelike dipole vector, we present 1-loop amplitudes that violate the optical theorem. A quantum mechanical system with nonlocal potential of finite extent in time also shows violation of unitarity.

In ultraperipheral relativistic deuteron on heavy-ion collisions, a photon emitted from the heavy nucleus may dissociate the deuterium ion. We find deuterium breakup cross sections of 1.24 barns for deuterium-gold collisions at a center of mass energy of 200 GeV per nucleon, as studied at the Relativistic Heavy Ion Collider, and 2.35 barns for deuterium-lead collisions at a center of mass energy of 6.2 TeV, as proposed for the Large Hadron Collider. In the latter case, the cross section is as large as that of hadronic interactions. The estimated error is 5%. We discuss the use of this process as a luminosity monitor and a 'tag' for moderate impact parameter collisions.

Mechanical surface treatments are known to be effective at improving the fatigue resistance of metallic alloys at elevated temperatures ({approx}550-600 C), even though the near-surface compressive residual stress fields have been annealed out. We have investigated the thermal stability of near-surface microstructures induced by deep rolling and laser-shock peening in an austentic stainless steel (AISI 304) and a titanium alloy (Ti-6Al-4V) using in situ hot-stage transmission electron microscopy. It is found that the improvements in fatigue resistance at elevated temperature are related to the high-temperature stability of the work-hardened near-surface microstructure in each case.

Mixed low-level waste (MLLW) contains both low-level radioactive materials and low-level hazardous chemicals. The hazardous component of mixed waste has characteristics identified by any or all of the following statutes: the Resource Conservation and Recovery Act of 1976 (RCRA), as amended; the Toxic Substances Control Act of 1976; and Washington State dangerous waste regulations. The Fluor Hanford Waste Management Project (WMP) is responsible for storing, treating, and disposing of solid MLLW, which includes organic and inorganic solids, organics and inorganic lab packs, debris, lead, mercury, long-length equipment, spent melters, and remote-handled (RH) and oversized MLLW. Hanford has 7,000 cubic meters, or about 25%, of the MLLW in storage at U.S. Department of Energy (DOE) sites. Hanford plans to receive 57,000 cubic meters from on-site generators, or about 50% of DOE's newly generated MLLW. In addition, the Hanford Environment Restoration Program and off-site generators having approved Federal Facility Consent Agreement site treatment plans will most likely send 200 cubic meters of waste to be treated and returned to the generators. Volumes of off-site waste receipts will be affected when the MLLW Record of Decision is issued as part of the process for the Hanford Site Solid Waste Environmental Impact Statement (EIS). …

The effect of laser energy on formation of a plasma inside a cavity was investigated. The temperature and electron number density of laser-induced plasmas in a fused silica cavity were determined using spectroscopic methods, and compared with laser ablation on a flat surface. Plasma temperature and electron number density during laser ablation in a cavity with aspect ratio of 4 increased faster with irradiance after the laser irradiance reached a threshold of 5 GW/cm{sup 2}. The threshold irradiance of particulate ejection was lower for laser ablation in a cavity compared with on a flat surface; the greater the cavity aspect ratio, the lower the threshold irradiance. The ionization of silicon becomes saturated and the crater depths were increased approximately by an order of magnitude after the irradiance reached the threshold. Phase explosion was discussed to explain the large change of both plasma characteristics and mass removal when irradiance increased beyond a threshold value. Self-focusing of the laser beam was discussed to be responsible for the decrease of the threshold in cavities.

The use of Diesel engines has strongly increased during the last years and now represents 40% of the sales in Europe and up to 50% of the number of cars in circulation for some countries. This success is linked not only to the economical aspect of the use of such vehicles, but also to the recent technological improvements of these engines. The new technical solutions (high pressure direct injection, turbocharger) have indeed allowed the increase of these engine performances while decreasing their fuel consumption, pollutant emissions and noise level. From an environment point of view, Diesel engines are nevertheless penalized by their particulates and NOx emissions. The study and the treatment of the particulate, highly criticized for their potential impact on health, are the subject of numerous works of characterizations and developments. PSA Peugeot Citroen has recently (2000) launched its particulate filter technology on several types of vehicles (500,000 vehicles with DPF have been sold today). In order to evaluate the durability of this technology over a long period of time, a study program has been set-up by ADEME (French Environmental Agency), IFP Powertrain, PSA Peugeot Citroen and Taxis G7 (a Parisian taxis Company). The objective is to study the …

The gasification of coal and other carbon-containing fuels provides the opportunity to produce energy more efficiently, and with significantly less environmental impact, than more-conventional combustion-based processes. In addition, the synthesis gas that is the product of the gasification process offers the option of ''polygeneration,'' i.e., the production of alternative products instead of power should it be economically favorable to do so. Because of these advantages, gasification is viewed as one of the key processes in the U.S. Department of Energy's Vision 21 power system. However, issues with both the reliability and the economics of gasifier operation will have to be resolved before gasification will be widely adopted by the power industry. Central to both enhanced reliability and economics is the development of materials with longer service lives in gasifier systems that can provide extended periods of continuous, trouble-free gasifier operation. The focus of the Advanced Refractories for Gasification project at the Albany Research Center is to develop improved refractory materials capable of withstanding the harsh, high-temperature environment created by the gasification reaction, and includes both the refractory lining that protects and insulates the slagging gasifier, as well as the thermocouple assemblies that are utilized to monitor gasifier operating temperatures. Current …

DOE complex contains many tank sludges contaminated with mercury. The high pH of these tank sludges typically fails to stabilize the mercury, resulting in these radioactive wastes also being characteristically hazardous or mixed waste. The traditional treatment for soluble inorganic mercury species is precipitation as insoluble mercuric sulfide. Sulfide treatment and a commercial mercury-stabilizing product were tested on surrogate sludges at various alkaline pH values. Neither the sulfide nor the commercial product stabilized the mercury sufficiently at the high pH of the tank sludges to pass the Toxicity Characteristic Leach Procedure (TCLP) treatment standards of the Resource Conservation and Recovery Act (RCRA). The commercial product also failed to stabilize the mercury in samples of the actual tank sludges.

Plasmatron reformers are being developed at MIT and ArvinMeritor [1]. In these reformers a special low power electrical discharge is used to promote partial oxidation conversion of hydrocarbon fuels into hydrogen and CO. The partial oxidation reaction of this very fuel rich mixture is difficult to initiate. The plasmatron provides continuous enhanced volume initiation. To minimize electrode erosion and electrical power requirements, a low current, high voltage discharge with wide area electrodes is used. The reformers operate at or slightly above atmospheric pressure. Plasmatron reformers provide the advantages of rapid startup and transient response; efficient conversion of the fuel to hydrogen rich gas; compact size; relaxation or elimination of reformer catalyst requirements; and capability to process difficult to reform fuels, such as diesel and bio-oils. These advantages facilitate use of onboard hydrogen-generation technology for diesel exhaust after-treatment. Plasma-enhanced reformer technology can provide substantial conversion even without the use of a catalyst. Recent progress includes a substantial decrease in electrical power consumption (to about 200 W), increased flow rate (above 1 g/s of diesel fuel corresponding to approximately 40 kW of chemical energy), soot suppression and improvements in other operational features.. Plasmatron reformer technology has been evaluated for regeneration of NOx …

It is clear from numerous energy/economic modeling exercises that addressing the challenges posed by global climate change will eventually require the active participation of all industrial sectors and all consumers on the planet. Yet, these and similar modeling exercises indicate that large stationary CO2 point sources (e.g., refineries and fossil-fired electric power plants) are often the first targets considered for serious CO2 emissions mitigation. Without participation of all sectors of the global economy, however, the challenges of climate change mitigation will not be met. Because of its operating characteristics, price structure, dependence on virtually one energy source (oil), enormous installed infrastructure, and limited technology alternatives, at least in the near-term, the transportation sector will likely represent a particularly difficult challenge for CO2 emissions mitigation. Our research shows that climate change induced price signals (i.e., putting a price on carbon that is emitted to the atmosphere) are in the near term insufficient to drive fundamental shifts in demand for energy services or to transform the way these services are provided in the transportation sector. We believe that a technological revolution will be necessary to accomplish the significant reduction of greenhouse gas emissions from the transportation sector. This paper presents an update …

A 1.9L turbo direct injection (TDI) diesel engine was modified to achieve the upcoming Tier 2 Bin 5 emission standard in combination with a NOx adsorber catalyst (NAC) and a diesel particulate filter (DPF). The primary objective for developing this test bed is to investigating the effects of different fuel sulfur contents on the performance of an advanced emission control system (ECS) in a light-duty application. During the development process, the engine-out emissions were minimized by applying a state-of-the-art combustion system in combination with cooled exhaust gas recirculation (EGR). The subsequent calibration effort resulted in emission levels requiring 80-90 percent nitrogen-oxide (NOx) and particulate matter (PM) conversion rates by the corresponding ECS. The strategy development included ean/rich modulation for NAC regeneration, as well as, the desulfurization of the NAC and the regeneration of the DPF. Two slightly different ECS were investigated and calibrated. The initial vehicle results in an Audi A4 station wagon over the federal test procedure (FTP), US 06, and the highway fuel economy test (HFET) cycle indicate the potential of these configuration to meet the future Tier 2 emission standard.

A systematic analysis of nuclear power plant (NPP) operation and radioactive wastes disposal (near-surface disposal and geologic disposal) in underground repositories has provided the basis for a comparison between the radiotoxicity and chemotoxicity as part of an EIA (environmental impact assessment) procedure. This contribution summarizes the hydrochemical mechanisms of transport and retardation processes, chemistry and migration behavior of radionuclides and chemical toxics in natural sorbents, especially bentonites. The effect of solubility and dissolution reactions, diffusion and sorption/desorption, complexation and variations in the aqueous phase composition, pH-value and oxidation-reduction properties and other phenomena affecting distribution coefficients (Kd values) is discussed.

This paper provides a brief background to the current position in the United Kingdom (UK) and provides an update on the various developments and initiatives within the field of radioactive waste management that have been taking place during 2002/03. These include: The UK Government's Department of Trade and Industry (DTi) review of UK energy policy; The UK Government's (Department of Environment, Food and Rural Affairs (Defra) and Devolved Administrations*) consultation program; The UK Government's DTi White Paper, 'Managing the Nuclear Legacy: A Strategy for Action'; Proposals for improved regulation of Intermediate Level Waste (ILW) conditioning and packaging. These various initiatives relate, in Nirex's opinion, to the three sectors of the industry and this paper will provide a comment on these initiatives in light of the lessons that Nirex has learnt from past events and suggest some conclusions for the future.

In a cooperative effort of the members of the South Texas Chapter of the Heath Physics Society (STC-HPS) and the Texas A&M University Nuclear Engineering Department, great efforts have been made to reach out and provide educational opportunities to members of the general public, school age children, and specifically teachers. These efforts have taken the form of Science Teacher Workshops (STW), visits to schools all over the state of Texas, public forums, and many other educational arenas. A major motivational factor for these most recent efforts can be directly tied to the attempt of the State of Texas to site a low-level radioactive waste facility near Sierra Blanca in West Texas. When the State of Texas first proposed to site a low level radioactive waste site after the Low-Level Radioactive Waste Policy Act of 1980 was passed, many years of political struggle ensued. Finally, a site at Sierra Blanca in far West Texas was selected for study and characterization for a disposal site for waste generated in the Texas Compact states of Maine, Vermont and Texas. During this process, the outreach to and education of the local public became a paramount issue.

Many solutions to meeting the 2007 and 2010 diesel emissions requirements have been suggested. On board production of hydrogen for in-cylinder combustion and exhaust after-treatment provide promising opportunities for meeting those requirements. Other benefits may include using syngas to rapidly heat up exhaust after-treatment catalysts during engine startup. HydrogenSource's development of a catalytic partial oxidation reformer for generating hydrogen from ultra-low sulfur diesel fuel is presented. The system can operate on engine exhaust and diesel fuel with no water tank. Test data for hydrogen regeneration of a lean NOx trap is presented showing 90% NOx conversion at temperatures as low as 150 degrees C and 99% conversion at 300 degrees C. Finally, additional efforts required to fully understand the benefits and commercial challenges of this technology are discussed.

The Office of Energy Efficiency and Renewable Energy (EERE) leads the federal government's research, development, and deployment (RD&D) efforts to provide reliable, affordable, and environmentally sound energy for America's future. EERE's role is to invest in high-risk, high-value research and development that is critical to the Nation's energy future and would not be sufficiently conducted by the private sector acting on its own. EERE also works with stakeholders to develop programs and policies to facilitate the deployment of advanced clean energy technologies and practices.

U.S. Army Corps of Engineers (USACE) works with other federal, and state agencies through several different programs on numerous Hazardous, Toxic, and Radioactive Waste (HTRW) sites. Formerly Utilized Sites Remediation Program (FUSRAP), Formerly Used Defense Sites (FUDS), EPA Superfund, Installation Restoration, Army Deactivated Nuclear Reactor Program, and many other programs present hazardous, radioactive, and mixed waste issues. While the USACE has a reputation of excellent dirt movers, little is discussed of our other waste management experiences. This paper discusses some of the challenges facing the Health Physics (HP) staff of the USACE. The HP staff is currently organized as one team, the Radiation Safety Support Team (RSST), comprised of 15 individuals at 6 locations across the country. With typical RSST missions including HP consultation to USACE activities world wide, many waste challenges arise. These challenges have involved radioactive wastes of all classifications and stability. Sealed and unsealed sources; instruments and dials; contaminated earth and debris; liquids; lab, reactor, and medical wastes are all successfully managed by the USACE. USACE also develops, evaluates, and utilizes waste treatment Types of radioactive waste at HTRW sites include: Low Level Radioactive Wastes (LLRW) (class A, B, C, and greater than C), 11e.(2), Transuranic (TRU), …

Results of numerical investigations of dynamic deformations of packages for air transportation of fresh nuclear fuel from Nuclear Power Plants are presented for the cases of axis and on-side impacts with hard surface at a speed of 90 meters/second (m/s). Modeling results on deformed structure shapes and kinematical parameters (displacements, decelerations, cramping) for axis impact are compared with experimental data. Use of this numerical-experimental technology gives new capabilities to analyze correctly the safety of such a package in accidents through modeling, which does not require implantation of expensive testing, thereby saving money.

Bringing a diesel retrofit product to market involves two primary phases: development and deployment. Critical product development steps include technology selection, system integration, laboratory and durability testing, and regulatory agency verification work. This initial product development phase is then followed by a deployment phase, which consists of building and managing the infrastructure for installation, distribution, service, sales and warranty support. Building relationships with regulators and air quality program developers is also a critical aspect of the deployment process. A successful path to market requires close cooperation between developer, distributor, customer and regulator.

The performance attributes of the U. S. Department of Energy's National Nuclear Security Administration Nevada Site Office Low-level Radioactive Waste (LLW) disposal facilities located at the Nevada Test Site transcend those of any other LLW disposal site in the United States. Situated at the southern end of the Great Basin, 244 meters (800 feet) above the water table, the Area 5 Radioactive Waste Management Site (RWMS) has utilized a combination of engineered shallow land disposal cells and deep augured shafts to dispose a variety of waste streams. These include high volume low-activity waste, classified material, and high-specific activity special case waste. Fifteen miles north of Area 5 is the Area 3 RWMS. Here bulk LLW disposal takes place in subsidence craters formed from underground testing of nuclear weapons. Earliest records indicate that documented LLW disposal activities have occurred at the Area 5 and Area 3 RWMSs since 1961 and 1968, respectively. However, these activities have only been managed under a formal program since 1978. This paper describes the technical attributes of the facilities, present and future capacities and capabilities, and provides a description of the process from waste approval to final disposition. The paper also summarizes the current status of …

This paper describes work under a U.S. DOE sponsored Ultra Clean Fuels project entitled ''Ultra Clean Fuels from Natural Gas,'' Cooperative Agreement No. DE-FC26-01NT41098. In this study we have examined the incremental benefits of moving from low sulfur diesel fuel and ultra low sulfur diesel fuel to an ultra clean fuel, Fischer-Tropsch diesel fuel produced from natural gas. Blending with biodiesel, B100, was also considered. The impact of fuel formulation on fuel injection timing, bulk modulus of compressibility, in-cylinder combustion processes, gaseous and particulate emissions, DPF regeneration temperature and urea-SCR NOx control has been examined. The primary test engine is a 5.9L Cummins ISB, which has been instrumented for in-cylinder combustion analysis and in-cylinder visualization with an engine videoscope. A single-cylinder engine has also been used to examine in detail the impacts of fuel formulation on injection timing in a pump-line-nozzle fueling system, to assist in the interpretation of results from the ISB engine.

This paper describes two industrial-scaled processes now being used to treat two problematic mercury waste categories: elemental mercury contaminated with radionuclides and radioactive solid wastes containing greater than 260-ppm mercury. The stabilization processes were developed by ADA Technologies, Inc., an environmental control and process development company in Littleton, Colorado. Perma-Fix Environmental Services has licensed the liquid elemental mercury stabilization process to treat radioactive mercury from Los Alamos National Laboratory and other DOE sites. ADA and Perma-Fix also cooperated to apply the >260-ppm mercury treatment technology to a storm sewer sediment waste collected from the Y-12 complex in Oak Ridge, TN.

Near surface disposal has been practiced for some decades, with a wide variation in sites, types and amounts of wastes, and facility designs employed. Experience has shown that the effective and safe isolation of waste depends on the performance of the overall disposal system, which is formed by three major components or barriers: the site, the disposal facility and the waste form. Near surface disposal also rely on active institutional controls, such as monitoring and maintenance. The objective of radioactive waste disposal is to isolate waste so that it does not result in undue radiation exposure to humans and the environment. The required degree of isolation can be obtained by implementing various disposal methods, of which near surface disposal represents an option commonly used and demonstrated in several countries. In near surface disposal, the disposal facility is located on or below the ground surface, where the protective covering is generally a few meters thick. The se facilities are intended to contain low and intermediate level waste without appreciable quantities of long-lived radionuclides.