As part of a larger study involving several organizations, the Advanced Neutron Source (ANS) Project made performance calculations for 19 different combinations of reactor core volume, fuel density and enrichment, power level, and other relevant parameters. These calculations were performed by Idaho National Engineering Laboratory (INEL) and Oak Ridge National Laboratory (ORNL). Subsequently, ORNL analyzed 14 other cases. With the aid of data from these 33 cases, the laboratory has been able to correlate the most important performance characteristics (peak thermal flux in the reflector and core life) with fuel enrichment, fuel density, and power. The correlations permits the investigation of additional cases without going to the expense of doing completely new neutronics calculations for each new one and can be used to prepare curves showing the effects of different enrichments and of different fuel densities within the entire range from existing technology to the very advanced, as yet undeveloped fuels that have been proposed from time to time.

Traditional manufacturing practice has depended upon Statistical Process Control (SPC) to eliminate defects. However, our research demonstrates that these sampling based methods significantly underestimate the tails of a distribution. As a consequence of the limitations of SPC, mistakes require different methods of control to achieve defect rates in the tens of parts per million range. Furthermore, product complexity contributes to defects resulting from both mistakes and excess variation. Correlations between defects and complexity lead to a new opportunity for selecting superior product concepts.

Depleted uranium hexafluoride (UF{sub 6}) at the US Department of Energy`s K-25 Site at Oak Ridge, TN has been stored in large steel cylinders which have undergone significant atmospheric corrosion damage over the last 35 years. A detailed experimental program to characterize and monitor the corrosion damage was initiated in 1992. Large amounts of corrosion scale and deep pits are found to cover cylinder surfaces. Ultrasonic wall thickness measurements have shown uniform corrosion losses up to 20 mils (0.5 mm) and pits up to 100 mils (2.5 mm) deep. Electrical resistance corrosion probes, time-of-wetness sensors and thermocouples have been attached to cylinder bodies. Atmospheric conditions are monitored using rain gauges, relative humidity sensors and thermocouples. Long-term (16 years) data are being obtained from mild steel corrosion coupons on test racks as well as attached directly to cylinder surfaces. Corrosion rates have been found to intimately related to the times-of-wetness, both tending to be higher on cylinder tops due to apparent sheltering effects. Data from the various tests are compared, discrepancies are discussed and a pattern of cylinder corrosion as a function of cylinder position and location is described.

Deep convection has an important role in the large-scale thermohaline circulation, which in turn plays a central part in determining global climate. Manabe and Stouffer`s climate simulations have shown that the thermal and dynamic structure of the oceans have pronounced changes in model climates with increased CO{sub 2}. In their simulations, the addition of low-salinity surface water at high latitudes prevents the ventilation of the deep ocean, thus reducing or in some cases nearly extinguishing the thermohaline circulation. Siegenthaler and Sarmiento remarked that whereas the ocean is the largest of the rapidly exchanging global carbon reservoirs and a major sink for anthropogenic carbon, this uptake capacity become available only when the whole ocean is chemically equilibrated with the new atmospheric CO{sub 2} concentration. The dynamics of the oceanic uptake of CO{sub 2} is therefore strongly determined by the rate of downward transport of CO{sub 2}-laden water from surface to depth. The importance of deep convection in moderating the uptake of CO{sub 2} by the ocean and its role in the meridional circulation, which affects climate by transporting heat from the tropics to the polar regions, motivates this research. The experiments described here were designed to study the sensitivity of the …

With five 8 pound high-explosive experiments, the author has investigated aspects of the containment phenomenology of partially decoupled events. In three experiments he observed multiple fractures and little cavity growth. In the final two experiments there were no fractures and cavity volumes grew by factors of approximately two and three. With the five experiments a spectrum of results ranging from hydraulic fracture - like crack propagation through multiple fracture propagation to the no fracture, or fully contained, case, was observed. For the multiple fracture experiments a partial residual stress field may have controlled the release of the cavity pressure. Measurements of cavity pressure versus time provided containment diagnostics; post event mining allowed visual observation of the cavities and fractures.

The orientations of hundreds of contiguous grains in high J{sub C} TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} deposits and (Bi, Pb){sub 2} Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} powder-in-tube tapes have been determined from electron back scatter diffraction patterns (EBSP). The misorientation angles and axes of rotation (angle/axis pairs) for grain boundaries connecting these grains were calculated. For both materials the population of low angle boundaries was found to be much larger than expected from calculations based on the macroscopic texture. The TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} deposits exhibit pronounced local texture which has been defined by EBSP and x-ray diffraction. Locally grains show significant in-plane (a-axis) alignment even though macroscopically a-axes are random, indicating the presence of colonies of grains with similar a-axis orientations. In (Bi, Pb){sub 2} Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes no local texture was observed. In both materials the existence of connected networks of small angle grain boundaries can be inferred. Coincident site lattice (CSL) grain boundaries are also present in higher than expected numbers. Grain boundary energy thus appears to play a significant role in enhancing the population of potentially strongly-linked boundaries. We propose that long range strongly-linked conduction occurs through a percolative network small angle …

In recent years a great deal of meteorological and climatological data has been exchanged between the two principal climate data centers of the United States and the former Soviet Union: the National Climatic Data Center (NCDC), in Asheville, North Carolina, and the Research Institute of Hydrometeorological Information (RIHMI) in Obninsk, Russia. This was accomplished via Working Group VIB (Influence of Environmental Changes on Climate) of the bilateral initiative known as the Agreement on Protection of the Environment, established on May 23, 1972 by the United States and the USSR. One of the key datasets compiled by RIHMI includes 3-hourly meteorological observations from 223 USSR stations for the period 1966-83. RIHMI has chosen to use daily and hourly data from these stations as the basis for considerable climate research efforts. These data (hereafter referred to as the RIHMI database) will soon be made available by both NCDC and the Department of Energy`s Carbon Dioxide Information Analysis Center (CDIAC) in Oak Ridge, Tennessee. The data have undergone extensive quality assurance checks at RIHMI, NCDC, and CDIAC. The data contain observations of some 22 meteorological variables, including near-surface air temperature, sea level pressure, precipitation amount, weather type, and total cloud cover. This study …

Scratch testing has long been used to assess the adhesion of a film to its substrate. As film thicknesses have decreased, the need for greater precision and sensitivity in the scratch testing apparatus has increased. To this end, a nanoindenter was modified to make finely controlled, low-load scratches. Scratches at various loads and two orientations of a Berkovich scratching diamond were made in films of 100 nm of gold and 200 nm of copper, each on single crystal silicon. For each film type, samples with no interlayer, with an SiO{sub 2} interlayer, and with a TiW on SiO{sub 2} interlayer were tested. The scratch morphology was found to vary in a regular way with load, diamond orientation and interlayer material.

Grain size evolution in a 0.17%C, 0.74%Mn plain carbon steel is investigated using a Gleeble 1500 thermomechanical simulator. Austenite grain growth measurements in the temperature range from 900 to 1150{degrees}C have been used to validate the Abbruzzese and Luecke model, which is recommended for simulating grain growth during reheating. For run-out table conditions, the ferrite grain size decreases from 1l{mu}m to 4{mu}m when the cooling rate from the austenite is increased from 1 to 80{degrees}C/s.

Glass formulation development depends on an understanding of the effects of glass composition on its processibility and product quality. Such compositional effects on properties in turn depend on the microscopic structure of the glass. Historically, compositional effects on macroscopic properties have been explored empirically, e.g., by measuring viscosity at various glass compositions. The relationship of composition to structure has been studied by microstructural experimental methods. More recently, computer simulation has proved a fruitful complement to these more traditional methods of study. By simulating atomic interaction over a period of time using the molecular dynamics method, a direct picture of the glass structure and dynamics is obtained which can verify existing concepts as well as permit ``measurement`` of quantities inaccessible to experiment. Atomistic simulation can be of particular benefit in the development of waste glasses. As vitrification is being considered for an increasing variety of waste streams, process and product models are needed to formulate compositions for an extremely wide variety of elemental species and composition ranges. The demand for process and product models which can predict over such a diverse composition space requires mechanistic understanding of glass behavior; atomistic simulation is ideally suited for providing this understanding. Moreover, while simulation …

Performance simulation has been conducted for a 4-effect lithium bromide-water chiller, capable of substantial performance improvement over state-of-the-art double-effect cycles. The system investigated includes four condensers and four desorbers coupled together, forming an extension of the conventional double-effect cycle; based on prior analytical studies, a parallel flow system was preferred over series flow, and double-condenser coupling was employed, to further improve performance. A modular computer code for simulation of absorption systems (ABSIM) was used to investigate the performances of the cycle. The simulation was carried out to investigate the influence of some major design parameters. A coefficient of performance around 2.0 (cooling) was calculated at the design point, with a heat supply temperature of 600{degrees}F (315{degrees}C) at the solution outlet from the high temperature desorber. With some optimization of the weak (pumped) solution flowrate and of the solution split among the four desorbers, this COP may be raised above 2.2.

Source size parameters measured via two-particle interferometry in experiment NA44 for 200 GeV/nucleon S+Pb collisions are compared to calculations using the RQMD event generator. Reasonable agreement is found in most cases. The event generator is then used to compare the {open_quotes}true{close_quotes} size of the particle-emitting source to the measured size parameters and to discuss the difficulties in defining the {open_quotes}true{close_quotes} source size.

For the very first time, it has recently proved possible to make a well-motivated, physically plausible, and self-consistent prediction of the Hyades G- and K-dwarf (Li,T{sub eff}) relationship that matches the long-unexplained observations. The method employs the latest Iglesias &, Rogers (OPAL) interior opacities and Alexander surface opacities (whose respective values are now themselves close to empirical predictions or estimates made earlier in this Hyades project), King`s recently discovered [O/Fe] enhancement (another prediction!) and utterly conventional PMS (pre-main-sequence) evolution unaided by arbitrary and ad hoc adjustable parameters. Thus, the following assumptions form a self-consistent set explaining the Hyades G- and K-dwarf (Li,T{sub eff}) observations: (i) Pop. I interior opacities are now essentially correct; (ii) Pop. I surface opacities are now essentially correct; (iii) The Hyades distance is now essentially correct; (iv) The Hyades [Fe/H] and [O/Fe] are now essentially correct, and possible changes in [Ne, Mg., or Si/Fe] are likely to have only a small effect; (v) Convective envelope overshooting is negligible; (vi) Quarreling with the above means finding at least two compensating errors in assumptions (i) through (v).

The Hanford K Basins contain roughly 2,000 tons of uranium metal fuel previously irradiated in N Reactor. Current plans call for the fuel to be moved to a new storage location in the next few years. This paper describes near term activities to gather data on the mechanical condition and chemical state of the fuel and associated sludge. These on-going in-situ, nondestructive, examinations are intended to complement hot cell examinations which are planned for the near future. Characterization data will feed decisions on interim storage, long term storage and the environmental documentation process as the fuel is relocated. Several techniques have been, or are planned to be, employed during the conduct of examinations in the K Basins. (1) A video survey using underwater cameras has been made for the open top canisters which hold fuel in the K East Basin. These data have given early assessments of cladding degradation, canister corrosion, fuel swelling, and canister/fuel interactions; (2) Ultrasonic measurements of the water level in gas traps connected to sealed canisters have been used to provide indications of gas generation in or water leakage into the canisters; (3) Sampling of gas and water from closed canisters of fuel in the K …

We have performed a statistically designed multiparameter experiment using response surface methodology to determine the optimum deposition and anneal conditions for PECVD silicon-oxide and silicon-nitride films on Si solar cells. Our process includes a unique in situ hydrogen plasma treatment to promote bulk defect passivation independently of surface effects. Our goal has been to define a process to optimize cell performance by minimizing recombination while also providing an effective antireflection coating. Our initial results show that excellent emitter-surface passivation, approaching that of the best thermally grown oxides, can be obtained using a single-layer nitride coating whose refractive index is optimized for antireflection purposes. Use of the PECVD-nitride instead of a TiO{sub 2} ARC resulted in an 11% increase in output power.

Femtosecond optical parametric oscillators (OPOs), synchronously pumped by Ti:Sapphire lasers, operating in the near infrared (IR) region are an important light source now under active development. The authors report the results of Ti:Sapphire synchronously pumped noncritically phase matched femtosecond OPOs that are based upon several crystals from the KTP family. The newly developed nonlinear crystal niobium doped KTP (Nb:KTP) has a greater birefringence than undoped KTP and is shown to extend the wavelength farther into the mid-IR. The authors report the first operation of a femtosecond OPO utilizing the solid-solution grown crystal Nb:KTP. Additionally, it is shown that CTA is very useful in mid-IR angle tuned OPOs.

Resolving the Ambiguities: An Industrial Hygiene (IAQ) Symposium was a one-day event designed to inform practicing industrial hygienists about highlight presentations made at Indoor Air `93. A broad range of topics was presented by invited speakers. Topics included were attempts to deal with guidelines and standards, questionnaires, odors and sensory irritation, respiratory allergies, neuroses, sick building syndrome (SBS), and multiple chemical sensitivity (MCS).

Principles of purifying of uranium metal by electrorefining are reviewed. Metal reactor fuel after irradiation is a form of impure uranium. Dissolution and deposition electrorefining processes were developed for spent metal fuel under the Integral Fast Reactor Program. Application of these processes to the conditioning of spent N-reactor fuel slugs is examined.

The Department of Energy (DOE) has successfully performed decontamination and decommissioning (D&D) on many production reactors it. DOE now has the challenge of performing D&D on a wide variety of other nuclear facilities. Because so many facilities are being closed, it is necessary to place many of them into a safe-storage status before conducting D&D-for perhaps as much as 20 yr. The challenge is to achieve this safe-storage condition in a cost-effective manner while remaining in compliance with applicable regulations. The DOE Office of Environmental Management, Office of Transition and Management, commissioned a lessons learned study of commercial experience with safe storage and transition to D&D. Although the majority of the commercial experience has been with reactors, many of the lessons learned presented in this paper are directly applicable to transitioning the DOE Weapons Complex.

The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators.

Lattice approach to weak matrix elements is reviewed. Recent progress in treating heavy quarks on the lattice is briefly discussed. Illustrative sample of results obtained so far is given. Among them I elaborate on B{sub K}, {line_integral}{sub B} and B {yields} K*{sub {gamma}}. Experimental implications especially with regard to constraints on the Standard Model (i.e. Wolfenstein) parameters, V{sub td} measurements and expectations for B{sub s}-{bar B}{sub s}, oscillations are briefly discussed.

The NSLS consists of two storage rings, a booster and a linac. A major upgrade of the control system (installed in 1978) was undertaken and has been completed. The computer architecture is being changed from a three level star-network to a two level distributed system. The microprocessor subsystem, host computer and workstations, communication link and the main software components are being upgraded or replaced. Since the NSLS rings operate twenty four hours a day a year with minimum maintenance time, the key requirement during the upgrade phase is a non-disruptive transition with minimum downtime. Concurrent with the upgrade, some immediate improvements were required. This paper describes the various components of the upgraded system and outlines the future plans.

High current YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO) thick films on flexible nickel substrates with textured buffer layers were deposited by using ion beam assisted deposition (IBAD). Pulsed laser deposited YBCO films were not only c-axis oriented with respect to the film surface but also strongly in-plane textured. The in-plane mosaic spread of YBCO films was {approximately} 10{degrees}. A critical current density of 8x10{sup 5} A/cm{sup 2} was obtained at 75 K and zero field for thin YBCO films. It was also demonstrated that thick YBCO films with a high critical current and excellent magnetic field dependence at liquid nitrogen temperature can be obtained on flexible nickel substrates by using the textured buffer layers. Issues encountered in producing the films were discussed.

Some recent investigations of the thermal equilibrium properties of kinks in a 1+1-dimensional, classical {phi}{sup 4} field theory are reviewed. The distribution function, kink density, correlation function, and certain thermodynamic quantities were studied both theoretically and via large scale simulations. A simple double Gaussian variational approach within the transfer operator formalism was shown to give good results in the intermediate temperature range where the dilute gas theory is known to fail.