A remediation of a gas cylinder disposal pit at Sandia National Laboratories, New Mexico has recently been completed. The cleanup prevented possible spontaneous releases of hazardous gases from corroded cylinders that may have affected nearby active test areas at Sandia`s Technical Area III. Special waste management, safety, and quality plans were developed and strictly implemented for this project. The project was conceived from a waste management perspective, and waste minimization and management were built into the planning and implementation phases. The site layout was planned to accommodate light and heavy equipment, storage of large quantities of suspect soil, and special areas to stage and treat gases and reactive chemicals removed from the pit, as well as radiation protection areas. Excavation was a tightly controlled activity using experienced gas cylinder and reactive chemical specialists. Hazardous operations were conducted at night under lights, to allow nearby daytime operations to function unhindered. The quality assurance plan provided specific control of, and documentation for, critical decisions, as well as the record of daily operations. Both hand and heavy equipment excavation techniques were utilized. Hand excavation techniques were utilized. Hand excavation techniques allows sealed glass containers to be exhumed unharmed. In the end, several dozen …

The U.S. Department of Energy (DOE) Headquarters and associated contractors have developed an IBM PC-based software package that estimates costs, schedules, and public and occupational health risks for a range of mixed-waste management options. A key application of the software package is the comparison of various waste-treatment options documented in the draft Site Treatment Plans prepared in accordance with the requirements of the Federal Facility Compliance Act of 1992. This automated Systems Analysis Methodology consists of a user interface for configuring complexwide or site-specific waste-management options; calculational algorithms for cost, schedule and risk; and user-selected graphical or tabular output of results. The mixed-waste management activities modeled in the automated Systems Analysis Methodology include waste storage, characterization, handling, transportation, treatment, and disposal. Analyses of treatment options identified in the draft Site Treatment Plans suggest potential cost and schedule savings from consolidation of proposed treatment facilities. This paper presents an overview of the automated Systems Analysis Methodology.

The authors review recent reactor- and spallation-source-based neutron scattering experiments on the magnetic fluctuations and order in a variety of doped transition metal oxides. In particular, data are shown for the NiO chain compound, Y{sub 2{minus}x}Ca{sub x}BaNiO{sub 5}, the two-dimensional cuprate superconductors La{sub 2{minus}x}Sr{sub x}CuO{sub 4} and YBa{sub 2}Cu{sub 3} O{sub 6+x}, and the classical three-dimensional ``Mott-Hubbard`` system V{sub 2{minus}y}O{sub 3}.

Over the past 8 or 9 years, the Savannah River Plant (SRP) has produced close to 4 million curies of cobalt-60 by irradiating cobalt-59 in the production reactors. This paper reviews past and current irradiations, cobalt-60 production methods, and costs.

In this manuscript we review briefly the history of Resonant Laser Ablation (RLA), and discuss some current ideas regarding sample preparation, laser parameters, and mechanisms. We also discuss current applications including spectral analysis of trace components, depth profiling of thin films and multilayer structures, and the use of RLA with the Ion Trap Mass Spectrometer (ITMS).

Risk assessment techniques vary from purely qualitative approaches, through a regime of semi-qualitative to the more traditional quantitative. Constraints such as time, money, manpower, skills, management perceptions, risk result communication to the public, and political pressures all affect the manner in which risk assessments are carried out. This paper surveys some risk matrix techniques, examining the uses and applicability for each. Limitations and problems for each technique are presented and compared to the others. Risk matrix approaches vary from purely qualitative axis descriptions of accident frequency vs consequences, to fully quantitative axis definitions using multi-attribute utility theory to equate different types of risk from the same operation.

At the Lawrence Livermore National Laboratory, we have prepared a Safety Analysis Report for the Department of Energy on our Building 332 Plutonium Handling Facility. This SAR includes an analysis of potential accident scenarios which could lead to offsite consequences to the public having not only radiological exposures, but also exposures to toxic gases such as chlorine. This paper presents a risk analysis of pressurized chlorine gas system proposed for use at Building 332. The focus of the analysis is to calculate the predicted frequency of an unmitigated leak of chlorine from the system which could result in the dispersal of the entire contents of the gas cylinder to the environment. Modeled are postulated valve leaks or pipe ruptures occurring anywhere in the distribution system, as well as the potential failure of leak mitigation. The fundamental credibility of this type of accident is established. The importance of a reliable leak mitigation system is demonstrated, and the dependence of the results on less than optimal data is discussed in the context of uncertainty and sensitivity analyses.

Experiments important to the future success of the Holifield Radioactive Ion Beam Facility (HRIBF) are in progress at the Oak Ridge National Laboratory which are designed to select the most appropriate target material for generating a particular radioactive ion beam (RIB). The 25-MV HHIRF tandem accelerator is used to implant stable complements of interesting radioactive elements into refractory targets mounted in a high-temperature FEBIAD ion source which is {open_quotes}on-line{close_quotes} at the UNISOR facility. The intensity versus time of implanted species, which diffuse from the high-temperature target material ({approximately}1700{degrees}C) and are ionized in the FEBIAD ion source, is used to determine release times for a particular projectile/target material combination. From such release data, diffusion coefficients can be derived by fitting the theoretical results obtained by computational solution of Fick`s second equation to experimental data. The diffusion coefficient can be used subsequently to predict the release properties of the particular element from the same material in other target geometries and at other temperatures, provided that the activation energy is also known. Diffusion coefficients for Cl implanted into and diffused from CeS and Zr{sub 5}Si{sub 3} and As, Br, and Se implanted into and diffused from Zr{sub 5}Ge{sub 3} have been derived from …

The US Department of Energy`s Hanford Site, located in southeastern Washington State, contains the largest amount and the most diverse collection of highly radioactive waste in the US. High-level radioactive waste has been stored at the Hanford Site in large, underground tanks since 1944. Approximately 217,000 M{sup 3} (57 Mgal) of caustic liquids, slurries, saltcakes, and sludges have accumulated in 177 tanks. In addition, significant amounts of {sup 90}Sr and {sup 137}Cs were removed from the tank waste, converted to salts, doubly encapsulated in metal containers, and stored in water basins. The Tank Waste Remediation System Program was established by the US Department of Energy in 1991 to safely manage and immobilize these wastes in anticipation of permanent disposal of the high-level waste fraction in a geologic repository. Since 1991, significant progress has been made in resolving waste tank safety issues, upgrading Tank Farm facilities and operations, and developing a new strategy for retrieving, treating, and immobilizing the waste for disposal.

The Waste Treatment and Minimization Group at Los Alamos National Laboratory has designed and will be constructing a transportable treatment system to treat low-level radioactive mixed waste generated during plating operations. The chemical and plating waste treatment system is composed of two modules with six submodules, which can be trucked to user sites to treat a wide variety of aqueous waste solutions. The process is designed to remove the hazardous components from the waste stream, generating chemically benign, disposable liquids and solids with low level radioactivity. The chemical and plating waste treatment system is designed as a multifunctional process capable of treating several different types of wastes. At this time, the unit has been the designated treatment process for these wastes: Destruction of free cyanide and metal-cyanide complexes from spent plating solutions; destruction of ammonia in solution from spent plating solutions; reduction of Cr{sup VI} to Cr{sup III} from spent plating solutions, precipitation, solids separation, and immobilization; heavy metal precipitation from spent plating solutions, solids separation, and immobilization, and acid or base neutralization from unspecified solutions.

The retained dose of implanted ions is limited by sputtering. It is known that a sacrificial layer deposited prior to ion implantation can lead to an enhanced retained dose. However, a higher ion energy is required to obtain a similar implantation depth due to the stopping of ions in the sacrificial layer. It is desirable to have a sacrificial layer of only a few monolayers thickness which can be renewed after it has been sputtered away. We explain the concept and describe two examples: (i) metal ion implantation using simultaneously a vacuum arc ion source and filtered vacuum arc plasma sources, and (ii) Metal Plasma Immersion Ion Implantation and Deposition (MePIIID). In MePIIID, the target is immersed in a metal or carbon plasma and a negative, repetitively pulsed bias voltage is applied. Ions are implanted when the bias is applied while the sacrificial layer suffers sputtering. Low-energy thin film deposition - repair of the sacrificial layer -- occurs between bias pulses. No foreign atoms are incorporated into the target since the sacrificial film is made of the same ion species as used in the implantation phase.

Nickel hydroxide is the electrochemically active material in the positive electrode of several important rechargeable alkaline-electrolyte batteries. It is believed that divalent Ni(OH){sub 2} is converted to trivalent NiOOH as the electrode is electrochemically oxidized during the battery charging process, and the reverse reaction (electrochemical reduction) occurs during battery discharge, however the details of this process are not completely understood. Because these electrochemical reactions involve surface charge-transfer processes, it is anticipated that surface modification may result in improved battery performance. We used broad-beam metal ion implantation and Metal Plasma Immersion Ion Implantation and Deposition to add cobalt and other species to the nickel electrode surface. The principle of the latter technique is explained in detail. It is shown that implanted and deposited cobalt ions act as a dopant of Ni(OH){sub 2}, and thereby alter its electronic conductivity. This electronic effect promotes lateral growth of NiOOH nodules and more-complete conversion of Ni(OH){sub 2} to NiOOH, which can be interpreted in terms of the nodule growth model. Other dopants such as Au, W, Pb, Ta and Ti{sub 4}O{sub 7} were also tested for suppressing the parasitic oxygen evolution reaction in rechargeable nickel cells.

Failure analysis is a critical element in the integrated circuit manufacturing industry. This paper reviews the changing role of failure analysis and describes major techniques employed in the industry today. Several advanced failure analysis techniques that meet the challenges imposed by advancements in integrated circuit technology are described and their applications are discussed. Future trends in failure analysis needed to keep pace with the continuing advancements in integrated circuit technology are anticipated.

Glass may be used to immobilize low-level mixed waste (LLMW) at the Savannah River Site because of its ability to accept a wide variety of components into its network structure. However, many common salts (sulfates, chlorides, phosphates, and chromates) present in the LLMW streams have limited solubility in glass. Processing and product problems may arise if the solubility of these salts is exceeded. In an effort to determine the factors that most affect salt solubilities, a statistical screening experiment was performed. The screening experiment, a Plackett-Burman design, allowed efficient estimation of the effects of variables, such as the composition of the glass, the temperature of the melt, the duration of melting, and the cooling rate. Each of these factors, along with a combination of sulfate, chloride, phosphate and chromate concentrations, were examined to provide an estimate of the solubility of each salt. The results of the screening experiment were interpreted to determine which variables should be further examined. The composition of the glass, especially the concentrations of boron, calcium and the alkalis, was found to have the greatest effect on the solubilities of the salts. This paper will discuss the results of the screening experiment and describe a path forward.

In order to measure the spacing of closely spaced dislocations, a method with sufficient spatial resolution must be used. The author presents a method for measuring such spatial resolution. Applications of this method to copper, NiAl, and Ni{sub 3}Al will be discussed.

The paper addresses several analytical topics in the design and qualification of piping systems which have a direct bearing on the prediction of stresses in the pipe and hence on the application of the equations of NB, NC and ND-3600 of the ASME Boiler and Pressure Vessel Code. For each of the analytical topics, the paper summarizes the current code requirements, if any, and the industry practice.

The effect of the pump, signal, and idler wave phases on three-wave nonlinear parametric mixing is investigated in a series of single-pass-gain experiments. Measurements are made with two angle-tuned KTP crystals in a 532 nm pumped, walkoff-compensated, optical parametric amplifier that is seeded by an 800 nm cw diode laser. In one of the measurements the second crystal is orientated to have its effective nonlinearity d{sub eff.} of opposite sign to that of the first crystal, so that all mixing that occurred in the first crystal is cancelled by the second when the phase mismatch {Delta}k{sub crystal 1} = {Delta}k{sub crystal 2} = 0. Efficient two-crystal amplification is subsequently restored by selecting the correct phase relationship for the three waves entering the crystal by inserting a dispersive plate between the crystals. The experimental results are explained in a straightforward manner with diagrams involving the three input wave polarizations. These results demonstrate that walkoff-compensated geometries require phase correction to achieve efficient mixing in the second crystal whenever the nonlinear interaction involves two extraordinary waves (e-waves). One practical application of this work may be lower oscillation thresholds and enhanced performance in walkoff-compensated optical parametric oscillators which use two e-waves.

The Energy and Environmental Research Corporation (EER), the Ohio Agricultural Research and Development Center (OARDC), the Will-Burt Company (W-B) and the U.S. Department of Energy (DOE) have successfully developed and completed pilot plant tests on a small scale atmospheric fluidized bed combustion (AFBC) system. This system can be used to generate electricity, and/or hot water, steam. Following successful pilot plant operation, commercial demonstration will take place at Cedar Lane Farms (CLF), near Wooster, Ohio. The system demonstration will be completed by the end of 1995. The project is being funded through a cooperative effort between the DOE, EER, W-B, OARDC, CLF and the Ohio Coal Development Office (OCDO). The small scale AFBC, has no internal heat transfer surfaces in the fluid bed proper. Combining the combustor with a hot air gas turbine (HAGT) for electrical power generation, can give a relatively high overall system thermal efficiency. Using a novel method of recovering waste heat from the gas turbine, a gross heat rate of 13,500 Btu/kWhr ({approximately}25% efficiency) can be achieved for a small 1.5 MW, plant. A low technology industrial recuperation type gas turbine is used that operates with an inlet blade temperature of 1450{degrees}F and a compression ratio of …

A new technique for the detection of trace concentrations of molecules in solution has been developed. This system utilizes the amplification characteristics of a bubble chamber in which energy deposition from laser absorption is monitored. In the experimental set-up, a trace quantity of solute is introduced into liquid propane that is contained in a small (10 ml) stainless steel cell at 120 psi. The propane is superheated by sudden reduction of the cell pressure. Before wall nucleated boiling occurs, target solute molecules are energized by a laser pulse. Absorption of pump laser energy results in the formation of nucleation centers which develop into bubbles and which in turn are detected by CCD camera. Preliminary experiments with crystal violet used as a test absorber have demonstrated detection sensitivity of 10 parts per trillion (ppt).

Interim storage of alkaline, high-level radioactive waste, from two generations of spent fuel reprocessing and waste management activities, has resulted in the accumulation of 238 million liters of waste in Hanford Site single and double-shell tanks. Before the 1990`s, the stored waste was believed to be: (1) chemically unreactive under its existing storage conditions and plausible accident scenarios; and (2) chemically stable. This paradigm was proven incorrect when detailed evaluation of tank contents and behavior revealed a number of safety issues and that the waste was generating flammable and noxious gases. In 1990, the Waste Tank Safety Program was formed to focus on identifying safety issues and resolving the ferrocyanide, flammable gas, organic, high heat, noxious vapor, and criticality issues. The tanks of concern were placed on Watch Lists by safety issue. This paper summarizes recent progress toward resolving Hanford Site high-level radioactive waste tank safety issues, including modeling, and analyses, laboratory experiments, monitoring upgrades, mitigation equipment, and developing a strategy to screen tanks for safety issues.

The double-shell waste tank 241SY101 (SY101) is a 3,785,400-liter tank used to store radioactive waste at the Hanford Site near Richland, Washington. The tank waste has formed two layers of sludge in the tank; a convective and a nonconvective layer. Ongoing reactions in the waste cause a buildup of hydrogen molecules that become trapped within the nonconvective layer of the waste. Various means of preventing the buildup of hydrogen molecules in the nonconvective layer have been investigated, including the use of a sonic probe that would transmit high-frequency acoustic pressure waves into the nonconvective layer of the waste. During the operation of the sonic probe, the pressure waves transmitted from the probe induce pressure time history loading on the inside surface of the primary tank. For low-frequency fluid-structure interaction loads, such as those associated with seismic events, the convective and impulsive effects of the waste-filled tank are well documented. However, for high-frequency loading, such as that associated with acoustic pressure waves, interactions between the waste and the primary tank are not understood. The pressure time history is represented by a harmonic function with a frequency range between 30 and 100 Hz. Structural analyses of the double-shell tank have been performed …

This paper marks the initial study into the technical and economic feasibility of converting the SAFARI-1 reactor in South Africa to LEU silicide fuel. Several MTR assembly geometries and LEU uranium densities have been studied and compared with MEU and HEU fuels. Two factors of primary importance for conversion of SAFARI-1 to LEU fuel are the economy of the fuel cycle and the performance of the incore and excore irradiation positions.

In 1992, a sinkhole was discovered above a Strategic Petroleum Reserve storage facility at Weeks Island, Louisiana. The oil is stored in an old salt mine located within a salt dome. In order to assess the hydrologic significance of the sink hole, an In Situ Permeable Flow Sensor was deployed within a sand-filled conduit in the salt dome directly beneath the sinkhole. The flow sensor is a recently developed instrument which uses a thermal perturbation technique to measure the magnitude and direction of the full 3-dimensional groundwater flow velocity vector in saturated, permeable materials. The flow sensor measured substantial groundwater flow directed vertically downward into the salt dome. The data obtained with the flow sensor provided critical evidence which was instrumental in assessing the significance of the sinkhole in terms of the integrity of the oil storage facility.

The authors intend to carry out a series of plasma lens experiments at the Final Focus Test Beam facility at SLAC. These experiments will be the first to study the focusing of particle beams by plasma focusing devices in the parameter regime of interest for high energy colliders, and is expected to lead to plasma lens designs capable of unprecedented spot sizes. Plasma focusing of positron beams will be attempted for the first time. They will study the effects of lens aberrations due to various lens imperfections. Several approaches will be applied to create the plasma required including laser ionization and beam induced tunneling ionization of a working gas--the latter which has never been observed before. The compactness of the device should prove to be of interest for applications at the SLC and the next generation linear colliders.