Publications

The topic of this technical presentation is Use Control Software. The nuclear weapon software design community is being subjected to many surety forces that are stretching the envelope of their designs. Given that software is a critical part of the use control system design, we must work to limit the errors of the software development process. The objective of this paper is to discuss a methodology that the author, as a member of the Security and Use Control Assessment Department, is working on. This is the first introduction of the proposed methodology. Software that is a part of any use control system, subsystem, device, or component is critical to the operation of that apparatus. The software is expected to meet the criteria of modern software quality. In a use control application, meeting the normal quality standards is short of the expectations in meeting the use control obligations. The NWC community expects the use control features of a nuclear weapon to provide assurance that the weapon is protected from unauthorized nuclear detonation. The methodology that the author is proposing will provide a focused scrutiny to software that is used in the hardware of use control systems, subsystems, devices, and components. The methodology proposes further scrutiny of the structure of the software, memory, variables, storage, and control features.

Scanning, ring-field lithographic cameras designed for 14-nm radiation can print 100-nm features on large chips. Mating high-efficiency illuminators are described.

This paper summarizes the recent hydrogeological investigations of several research organizations on waste confinement at the major radioactive waste (RW) burial sites immediately adjacent to the Chernobyl Nuclear Power Plant (Ch. NPP). Hydrogeological conditions and radiologic ground-water contamination levels are described. Ongoing ground-water monitoring practices are evaluated. The chemical and physical characteristics of the radionuclides within the burial sites are considered. Ground water and radionuclide transport modeling studies related to problems of the RW disposal sites are also reviewed. Current concerns on future impacts of the RW burial sites on the hydrological environment and water resources of the Ch.NPP area are discussed.

A new direction for the national laboratories is to assist US business with research and development, primarily through cooperative research and development agreements (CRADAs). Technology transfer to the private sector has been very successful as over 200 CRADAs are in place at Sandia. Because of these cooperative efforts, technology has evolved into some new areas not commonly associated with the former mission of the national laboratories. An example of this is the analysis of fabric structures. Explicit analyses and expertise in constructing parachutes led to the development of a next generation automobile airbag; which led to the construction, testing, and analysis of the Jet Propulsion Laboratory Mars Environmental Survey Lander; and finally led to the development of CAD based custom garment designs using 3D scanned images of the human body. The structural analysis of these fabric structures is described as well as a more traditional example Sandia with the test/analysis correlation of the impact of a weapon container.

Platform-independent Interaction Collaborative Environments (ICE) technologies include support for simultaneous display and control of unmodified X application software by two or more people, at separate locations, using different workstation hardware. Audio and video provide remote collaborators with the ability to discuss what they are all simultaneously seeing on their workstations. Remote pointing and marking capabilities are also provided independent of the application. The authors briefly describe their X application sharing work, and requirements for supporting tools, including multi-media. Finally they review some of the pilot project network applications of their work to robotics and manufacturing environments.

The SEAMIST{trademark} inverting membrane deployment system has been used successfully at the Mixed Waste Landfill Integrated Demonstration (MWLID) for multipoint vapor sampling/pressure measurement/permeability measurement/sensor integration demonstrations and borehole lining. Several instruments were deployed inside the SEAMIST{trademark} lined boreholes to detect metals, radionuclides, moisture, and geologic variations. The liner protected the instruments from contamination, maintained support of the uncased borehole wall, and sealed the total borehole from air circulation. The current activities have included the installation of three multipoint vapor sampling systems and sensor integration systems in 100-foot-deep vertical boreholes. A long term pressure monitoring program has recorded barometric pressure effects at depth with relatively high spatial resolution. The SEAMIST{trademark} system has been integrated with a variety of hydrologic and chemical sensors for in-situ measurements, demonstrating its versatility as an instrument deployment system which allows easy emplacement and removal. Standard SEAMIST{trademark} vapor sampling systems were also integrated with state-of-the-art VOC analysis technologies (automated GC, UV laser fluorometer). The results and status of these demonstration tests are presented.

Environmental and operator safety concerns are leading to the elimination of trichloroethylene (TCE) and chlorofluorocarbon (CFC) solvents in electronic component cleaning processes that remove rosin flux, organic and inorganic contamination, and particulates. Present processes depend heavily on these solvents for manual spray cleaning of small components and subassemblies. Use of alternative solvent systems can lead to longer processing times and reduced quality. Automated spray cleaning can improve the quality of the cleaning process, thus enabling the productive use of environmentally conscious materials, while minimizing personnel exposure to hazardous materials. In addition, the use of robotic and automated systems can reduce the manual handling of parts that necessitates additional cleaning. We describe the development of a prototype robotic system for cleaning electronic components in a spray cleaning workcell. An important feature of the prototype system is the capability to generate the robot paths and motions automatically from the CAD models of the part to be cleaned, and to embed cleaning process knowledge into the automatically programmed operations.

This document describes Sandia National Laboratories involvement with scientists and engineers at various organizations within the states of the Former Soviet Union (FSU). The purpose of these interactions is twofold: first, to acquire technical information to enhance United States technology and second, to assist FSU states in converting their defense-oriented industry to civilian, market- oriented business.

The technical feasibility of emplacing a barrier beneath a waste site using directionally drilled boreholes and permeation grouting was investigated. The benefits of this emplacement system are: (1) Directionally drilled boreholes provide access beneath a waste site without disturbing the waste; (2) interim containment of contaminants allows time for the development of remediation options; (3) in the interim, the volume of waste remains fixed; (4) barriers may enhance the effectiveness of in situ remediation actions; and (5) barrier systems may provide permanent waste containment .

The Solar Thermal Design Assistance Center (STDAC) at Sandia National Laboratories is a resource provided by the US Department of Energy`s Solar Thermal Program. Its major objectives are to accelerate the use of solar thermal systems through (a) direct technical assistance to users, (b) cooperative test, evaluation, and development efforts with private industry, and (c) educational outreach activities. This report outlines the major activities and accomplishments of the STDAC in Fiscal Year 1993. The report also contains a comprehensive list of persons who contacted the STDAC by telephone for information or technical consulting.

A dry barrier is a layer of geologic material that is dried by air flow. An active dry barrier system can be designed, installed, and operated as part of a landfill cover system. An active system uses blowers and fans to move air through a high-permeability layer within the cover system. Depending principally on the air-flow rate, it is possible for a dry barrier to remove enough water to substantially reduce the likelihood of water percolating through the cover system. If a material with a relatively great storage capacity, such as processed tuff, is used as the coarse layer, then the efficiency of the dry barrier will be increased.

The US Nuclear Regulatory Commission (NRC) maintains a technical training center at Chattanooga, Tennessee to provide appropriate training to both new and experienced NRC employees. This document describes a one-week course in reactor, safety concepts. The course consists of five modules: (1) historical perspective; (2) accident sequences; (3) accident progression in the reactor vessel; (4) containment characteristics and design bases; and (5) source terms and offsite consequences. The course text is accompanied by slides and videos during the actual presentation of the course.

An accident management strategy has been proposed in which the reactor coolant system is intentionally depressurized during an accident. The aim is to reduce the containment pressurization that would result from high pressure ejection of molten debris at vessel breach. Probabilistic risk assessment (PRA) methods were used to evaluate this strategy for the Surry nuclear power plant. Sensitivity studies were conducted using event trees that were developed for the NUREG-1150 study. It was found that depressurization (intentional or unintentional) had minimal impact on the containment failure probability at vessel breach for Surry because the containment loads assessed for NUREG-1150 were not a great threat to the containment survivability. An updated evaluation of the impact of intentional depressurization on the probability of having a high pressure melt ejection was then made that reflected analyses that have been performed since NUREG-1150 was completed. The updated evaluation confirmed the sensitivity study conclusions that intentional depressurization has minimal impact on the probability of a high pressure melt ejection. The updated evaluation did show a slight benefit from depressurization because depressurization delayed core melting, which led to a higher probability of recovering emergency core coolant injection, thereby arresting the core damage.

Vertical electric fields, azimuthal magnetic fields, and earth step potentials at ground level have been measured at 10 and 20 meters from the base of triggered lightning flashes. For incident stroke peak currents in the range of 4.4 to 29 kA, vertical electric field change amplitudes as high as 210 kV/m were observed at 10 m, with rise times of the order of a few microseconds. Magnetic fields were found to follow Ampere`s law closely at both 10 and 20 m. Earth step potentials measured over a 0.5-m radial distance at the 10-m and 20m stations were linear with and had the same waveforms as the stroke currents. The step voltages exhibited a l/r distance dependence between the two measurement distances. A model that incorporates the presence of a thin surface layer, due to rain water saturation, of much higher conductivity than the bulk of the underlying earth is proposed to explain the observed behavior. Tests were also carried out to evaluate the effectiveness of several concepts for protecting a small exposed object, such as a piece of ordnance at the site of a transportation accident, from either a direct strike or from the indirect effects of electromagnetic fields produced by a nearby lightning flash to ground. Photographs of the occurrence of significant radial filamentary arcing along the surface of the ground from the strike points were acquired. This type of arcing, with a maximum radial extent of at least 20 m, was observed on six of seven of triggered flashes and on all strokes of 15-kA peak amplitude or higher.

Goal was to obtain dynamic mechanical property data on a quartz phenolic (abbreviated QP) composite. Shock loading and shock release measurements have been conducted using impact techniques utilizing both a light-gas gun and a powder gun at impact pressures up to 20 GPa. The primary diagnostic tool used was a velocity interferometer. The data analysis includes Hugoniot measurements to give both pressure-particle velocity and shock velocity-particle velocity relationships; spall measurements to determine the fracture stress at which the material spells; and attenuation measurements to determine the shock attenuation with material thickness. The QP Hugoniot relationship was found to be significantly different than that of a phenolic without a filler material indicating that the impedance of the QP used in this investigation was higher. The spall strength was measured to be {approximately}0.075 GPa, similar to nonfilled phenolic, which indicated that the presence of quartz fibers was not contributing to the fracture strength. The material was found to attenuate an imposed shock of approximately 6.3 GPa pressure and 0.18 {mu}s to 50% of the initial impact value after a propagation distance of 7mm.

Sandia National Laboratories is currently involved in the optimization of a Plane Shock Generator Explosive Lens (PSGEL). The PSGEL component consists of a detonator, explosive, brass cone and tamper housing. The purpose of the PSGEL component is to transmit a plane shock wave through the 4340 steel bulkhead (wave separator) which has a ferro-electric (PZT)ceramic disk attached to the opposite surface of the steel bulkhead. The planar shock wave depolarizes the PZT 65/35 ferro-electric ceramic to produce an electrical output. One aspect of the optimization program involves the possible replacement of 4340 steel with PH13-8Mo steel for the bulkhead. These materials, as well as the PZT 65/35 ferro-electric ceramic and the brass for the cone, required the stock characterization with respect to Hugoniot parameters. The work presented here gives the shock Hugoniot values for these four materials and documents their measurements.

CIRCE2 is a computer code for modeling the optical performance of three-dimensional dish-type solar energy concentrators. Statistical methods are used to evaluate the directional distribution of reflected rays from any given point on the concentrator. Given concentrator and receiver geometries, sunshape (angular distribution of incident rays from the sun), and concentrator imperfections such as surface roughness and random deviation in slope, the code predicts the flux distribution and total power incident upon the target. Great freedom exists in the variety of concentrator and receiver configurations that can be modeled. Additionally, provisions for shading and receiver aperturing are included.- DEKGEN2 is a preprocessor designed to facilitate input of geometry, error distributions, and sun models. This manual describes the optical model, user inputs, code outputs, and operation of the software package. A user tutorial is included in which several collectors are built and analyzed in step-by-step examples.

The Small-Scale Seal Performance Tests, Series C, a set of in situ experiments conducted at the Waste Isolation Pilot Plant, are designed to evaluate the performance of various seal materials emplaced in large (0.9-m-diameter) boreholes. This report documents the results of fluid (brine) flow testing and water and clay content analyses performed on one emplaced seal comprised of 100% salt blocks and 50%/50% crushed salt/bentonite blocks and disassembled after nearly three years of brine injection testing. Results from the water content analyses of 212 samples taken from within this seal show uniform water content throughout the 50%/50% salt/bentonite blocks with saturations about 100%. Clay content analyses from the 100% salt endcaps of the seal show a background clay content of about 1% by weight uniformly distributed, with the exception of samples taken at the base of the seal at the borehole wall interface. These samples show clay contents up to 3% by weight, which suggests some bentonite may have migrated under pressure to that interface. Results of the brine-flow testing show that the permeability to brine for this seal was about 2 to 3 {times} 10{sup {minus}4} darcy (2 to 3 {times} 10{sup {minus}16} m{sup 2}).

This report documents the state of the art in experimental and theoretical techniques for determining reaction mechanisms and chemical kinetics of heterogeneous reactions relevant to the chemical vapor deposition of semiconductor materials. It summarizes the most common ultra-high vacuum experimental techniques that are used and the types of rate information available from each. Several case studies of specific chemical systems relevant to the microelectronics industry are described. Theoretical methods for calculating heterogeneous reaction rate constants are also summarized.

A new technology called the In Situ Permeable Flow Sensor has been developed at Sandia National Laboratories. These sensors use a thermal perturbation technique to directly measure the direction and magnitude of the full three dimensional groundwater flow velocity vector in unconsolidated, saturated, porous media. The velocity measured is an average value characteristic of an approximately 1 cubic meter volume of the subsurface. During a test at the Savannah River Site in South Carolina, two flow sensors were deployed in a confined aquifer in close proximity to a well which was screened over the entire vertical extent of the aquifer and the well was pumped at four different pumping rates. In this situation horizontal flow which is radially directed toward the pumping well is expected. The flow sensors measured horizontal flow which was directed toward the pumping well, within the uncertainty in the measurements. The observed magnitude of the horizontal component of the flow velocity increased linearly with pumping rate, as predicted by theoretical considerations. The measured horizontal component of the flow velocity differed from the predicted flow velocity, which was calculated with the assumptions that the hydraulic properties of the aquifer were radially homogeneous and isotropic, by less than a factor of two. Drawdown data obtained from other wells near the pumping well during the pump test indicate that the hydraulic properties of the aquifer are probably not radially homogeneous but the effect of the inhomogeneity on the flow velocity field around the pumping well was not modeled because the degree and distribution of the inhomogeneity are unknown. Grain size analysis of core samples from wells in the area were used to estimate the vertical distribution of hydraulic conductivity.

After a series of meetings held in response to an Unsatisfactory Report on the use of vacuum cleaners, an experimental study of commonly available vacuum cleaners was conducted. The object of the study was to evaluate the effectiveness of the cleaners as electrostatic generators. The electrical charges generated by the machine can inadvertently be transferred in normal operations to electroexplosive devices (EEDs), thereby creating a potentially hazardous situation. In the course of this study, it was determined that many inexpensive commercial cleaners could be used safely providing certain modifications were made. Details of the required modification and rationale for the modification are presented in this report.

The Integrated Engineering Information Technology (IEIT) project is providing a comprehensive, easy-to-use computer network solution or communicating with coworkers both inside and outside Sandia National Laboratories. IEIT capabilities include computer networking, electronic mail, mechanical design, and data management. These network-based tools have one fundamental purpose: to help create a concurrent engineering environment that will enable Sandia organizations to excel in today`s increasingly competitive business environment.

SPH (Smoothed Particle Hydrodynamics) is a gridless Lagrangian technique which is appealing as a possible alternative to numerical techniques currently used to analyze high deformation impulsive loading events. In the present study, the SPH algorithm has been subjected to detailed testing and analysis to determine its applicability in the field of solid dynamics. An important result of the work is a rigorous von Neumann stability analysis which provides a simple criterion for the stability or instability of the method in terms of the stress state and the second derivative of the kernel function. Instability, which typically occurs only for solids in tension, results not from the numerical time integration algorithm, but because the SPH algorithm creates an effective stress with a negative modulus. The analysis provides insight into possible methods for removing the instability. Also, SPH has been coupled into the transient dynamics finite element code PRONTO, and a weighted residual derivation of the SPH equations has been obtained.

This report documents the reentry safety analyses conducted for the TOPAZ II Nuclear Electric Propulsion Space Test Program (NEPSTP). Scoping calculations were performed on the reentry aerothermal breakup and ground footprint of reactor core debris. The calculations were used to assess the risks associated with radiologically cold reentry accidents and to determine if constraints should be placed on the core configuration for such accidents. Three risk factors were considered: inadvertent criticality upon reentry impact, atmospheric dispersal of U-235 fuel, and the Special Nuclear Material Safeguards risks. Results indicate that the risks associated with cold reentry are very low regardless of the core configuration. Core configuration constraints were therefore not established for radiologically cold reentry accidents.

The US Department of Energy (DOE) is responsible for management and disposal of large quantities of depleted uranium (DU) in the DOE complex. Viable economic options for the use and eventual disposal of the material are needed. One possible option is the use of DU as shielding material for vitrified Defense High-Level Waste (DHLW) storage, transportation, and disposal packages. Use of DU as a shielding material provides the potential benefit of disposing of significant quantities of DU during the DHLW storage and disposal process. Two DU package concepts have been developed by Sandia National Laboratories. The first concept is the Storage/Disposal plus Transportation (S/D+T) package. The S/D+T package consists of two major components: a storage/disposal (S/D) container and a transportation overpack. The second concept is the S/D/T package which is an integral storage, transportation, and disposal package. The package concept considered in this analysis is the S/D+T package with seven DHLW waste canisters. The S/D+T package provides shielding and containment for the DHLW waste canisters. The S/D container is intended to be used as an on-site storage and repository disposal container. In this analysis, the S/D container is constructed from a combination of stainless steel and DU. Other material combinations, such as mild steel and DU, are potential candidates. The transportation overpack is used to transport the S/D containers to a final geological repository and is not included in this analysis.