Publications

A formal program of cooperation between the US Department of Energy and the Belarusian regulatory agency Promatomnazdor (PAN) began in 1994. A visit to the Belarusian Sosny Science and Technology Center (SSTC) by representatives from the United States, Sweden, Japan, and the International Atomic Energy Agency resulted in a multinational program of cooperation to enhance the existing material protection, control, and accounting systems in place at Sosny. Specific physical-protection-related recommendations included upgrades to the physical protection systems at Buildings 33 and 40 at Sosny and the security systems in the SSTC central alarm station. US experts, in conjunction with the multinational team and Belarus representatives, have reviewed initial designs for physical protection upgrades at Sosny. Subsequently, the United States assumed an essential role for funding and technical oversight for enhancements at the SSTC, aspects of its emergency communication systems, and the upgrade of the SSTC site access control system. This paper addresses the status of physical protection enhancements at the Sosny site.

AIBN-iniliated functionalization of polyphenylsilane with allyl(ethoxy) silanes generates (elhoxysilylpropyl)polysilanes in good yield. Amorphous polysilane-polysiloxane hybrid nanocomposites can be prepared by the mild, acid-catalyzed sol-gel hydrolysis-condensation of polysilane-based precursors 2a-c at the pendant alkoxysilane residues. UV-Vis and multinuclear NMR spectroscopies establish the mention of the polysilane chromophore and attached organic residues; NMR also reflects the degree of condenstion at the siloxane silicon nuclei. The bulk morphology of the resulting dried gels can be influenced by the choice of solvent removal from the wet gel Aqueous extraction of solvent results in ponporous xerogels. while solvent removal by supercritical CO2 yields mesoporous aerogels with retention of the wet gel surface area. In hybrid materials 3a-c the polysilane chromophore is homogeneously dispersed in. and covalently bound to, a highly crosslinked siloxane matrix. The demonstrated ability to homogeneously entrain polysilanes within glass matrices holds great potential for fabricating sohisticated electronic, NLO and photoconducting devices.

The post cold war security environment poses both difficult challenges and encouraging opportunities. Some of the most difficult challenges are related to regional conflict and the proliferation of weapons of mass destruction. New and innovative approaches to prevent the proliferation of weapons of mass destruction are essential. More effort must be focused on underlying factors that motivate countries to seek weapons of mass destruction. Historically the emphasis has been on denial: denying information, denying technology, and denying materials necessary to build such weapons. Though still important, those efforts are increasingly perceived to be insufficient, and initiatives that address underlying motivational factors are needed. On the opportunity side, efforts to establish regional dialogue and confidence-building measures are increasing in many areas. Such efforts can result in cooperative agreements on security issues such as border control, demilitarized zones, weapons delivery systems, weapons of mass destruction free zones, environmental agreements, and resource sharing. In some cases, implementing such cooperative agreements will mean acquiring, analyzing, and sharing large quantities of data and sensitive information. These arrangements for ``cooperative monitoring`` are becoming increasingly important to the security of individual countries, regions, and international institutions. However, many countries lack sufficient technical and institutional infrastructure to take full advantage of these opportunities. Constructing a peaceful twenty-first century will require that technology is brought to bear in the most productive and innovative ways to meet the challenges of proliferation and to maximize the opportunities for cooperation.

The MELCOR Accident Consequence Code System (MACCS), publicly distributed since 1987, was developed to estimate the potential impacts to the surrounding public of severe accidents at nuclear power plants. The principal phenomena considered in MACCS are atmospheric transport and deposition under time-variant meteorology, short-term and long-term mitigative actions and exposure pathways, deterministic and stochastic health effects, and economic costs of mitigative actions. At this time, no other publicly available code in the US offers all these capabilities. MACCS2 represents a major enhancement of the capabilities of its predecessor MACCS. MACCS2 was developed as a general-purpose analytical tool applicable to diverse reactor and nonreactor Department of Energy (DOE) facilities. The MACCS2 package includes three primary enhancements: (1) a more flexible emergency response model, (2) an expanded library of radionuclides, and (3) a semidynamic food-chain model. The new code features allow detailed evaluations of risks to workers at nearby facilities on large DOE reservations and allow the user to assess the potential impacts of over 700 radionuclides that cannot be considered with MACCS.

Batch-fabricated silicon seismic transducers could revolutionize the discipline of seismic monitoring by providing inexpensive, easily deployable sensor arrays. Our ultimate goal is to fabricate seismic sensors with sensitivity and noise performance comparable to short-period seismometers in common use. We expect several phases of development will be required to accomplish that level of performance. Traditional silicon micromachining techniques are not ideally suited to the simultaneous fabrication of a large proof mass and soft suspension, such as one needs to achieve the extreme sensitivities required for seismic measurements. We have therefore developed a novel {open_quotes}mold{close_quotes} micromachining technology that promises to make larger proof masses (in the 1-10 mg range) possible. We have successfully integrated this micromolding capability with our surface-micromachining process, which enables the formation of soft suspension springs. Our calculations indicate that devices made in this new integrated technology will resolve down to at least sub-{mu}G signals, and may even approach the 10{sup -10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

The goal of the Waveform Correlation Event Detection System (WCEDS) Project at Sandia Labs has been to develop a prototype of a full-waveform correlation based seismic event detection system which could be used to assess potential usefulness for CTBT monitoring. The current seismic event detection system in use at the IDC is very sophisticated and provides good results but there is still significant room for improvement, particularly in reducing the number of false events (currently being nearly equal to the number of real events). Our first prototype was developed last year and since then we have used it for extensive testing from which we have gained considerable insight. The original prototype was based on a long-period detector designed by Shearer (1994), but it has been heavily modified to address problems encountered in application to a data set from the Incorporated Research Institutes for Seismology (IRIS) broadband global network. Important modifications include capabilities for event masking and iterative event detection, continuous near-real time execution, improved Master Image creation, and individualized station pre-processing. All have been shown to improve bulletin quality. In some cases the system has detected marginal events which may not be detectable by traditional detection systems, but definitive conclusions cannot be made without direct comparisons. For this reason future work will focus on using the system to process GSETT3 data for comparison with current event detection systems at the IDC.

An initial security evaluation of the proposed International Monitoring System (IMS) suggests safeguards at various points in the IMS to provide reliable information to the user community. Modeling the IMS as a network of information processing nodes provides a suitable architecture for assessing data surety needs of the system. The recommendations in this paper include the use of public-key authentication for data from monitoring stations and for commands issued to monitoring stations. Other monitoring station safeguards include tamper protection of sensor subsystems, preservation of data (i.e. short-term archival), and limiting the station`s network services. The recommendations for NDCs focus on the need to provide a backup to the IDC for data archival and data routing. Safeguards suggested for the IDC center on issues of reliability. The production of event bulletins should employ {open_quotes}two-man{close_quotes} procedures. As long as the data maintains its integrity, event bulletins can be produced by NDCs as well. The effective use of data authentication requires a sound key management system. Key management systems must be developed for the authentication of data, commands, and event bulletins if necessary. It is recommended that the trust placed in key management be distributed among multiple parties. The recommendations found in this paper offer safeguards for identified vulnerabilities in the IMS with regard to data surety. However, several outstanding security issues still exist. These issues include the need to formalize and obtain a consensus on a threat model and a trust model for the IMS. The final outstanding security issue that requires in-depth analysis concerns the IDC as a potential single point of failure in the current IMS design.

This paper summarizes the requirements for the interpolation scheme needed for the CTBT Knowledge Base and discusses interpolation issues relative to the requirements. Based on these requirements, a methodology for providing an accurate and robust interpolation scheme for the CTBT Knowledge Base is proposed. The method utilizes a Delaunay triangle tessellation to mesh the Earth`s surface and employs the natural-neighbor interpolation technique to provide accurate evaluation of geophysical data that is important for CTBT verification. The natural-neighbor interpolation method is a local weighted average technique capable of modeling sparse irregular data sets as is commonly found in the geophysical sciences. This is particularly true of the data to be contained in the CTBT Knowledge Base. Furthermore, natural neighbor interpolation is first order continuous everywhere except at the data points. The non-linear form of the natural-neighbor interpolation method can provide continuous first and second order derivatives throughout the entire data domain. Since one of the primary support functions of the Knowledge Base is to provide event location capabilities, and the seismic event location algorithms typically require first and second order continuity, this is a prime requirement of any interpolation methodology chosen for use by the CTBT Knowledge Base.

It is recognized that some dynamic and noise environments are characterized by time histories which are not Gaussian. An example is high intensity acoustic noise. Another example is some transportation vibration. A better simulation of these environments can be generated if a zero mean non-Gaussian time history can be reproduced with a specified auto (or power) spectral density (ASD or PSD) and a specified probability density function (pdf). After the required time history is synthesized, the waveform can be used for simulation purposes. For example, modem waveform reproduction techniques can be used to reproduce the waveform on electrodynamic or electrohydraulic shakers. Or the waveforms can be used in digital simulations. A method is presented for the generation of realizations of zero mean non-Gaussian random time histories with a specified ASD, and pdf. First a Gaussian time history with the specified auto (or power) spectral density (ASD) is generated. A monotonic nonlinear function relating the Gaussian waveform to the desired realization is then established based on the Cumulative Distribution Function (CDF) of the desired waveform and the known CDF of a Gaussian waveform. The established function is used to transform the Gaussian waveform to a realization of the desired waveform. Since the transformation preserves the zero-crossings and peaks of the original Gaussian waveform, and does not introduce any substantial discontinuities, the ASD is not substantially changed. Several methods are available to generate a realization of a Gaussian distributed waveform with a known ASD. The method of Smallwood and Paez (1993) is an example. However, the generation of random noise with a specified ASD but with a non-Gaussian distribution is less well known.

One of the major thrusts established under the FAA`s National Aging Aircraft Research Program is to foster new technologies associated with civil aircraft maintenance. Recent DOD and other government developments in the use of bonded composite patches on metal structures has supported the need for research and validation of such doubler applications on U.S. certificated airplanes. Composite patching is a rapidly maturing technology which shows promise of cost savings on aging aircraft. Sandia Labs is conducting a proof-of-concept project with Delta Air Lines, Lockheed Martin, Textron, and the FAA which seeks to remove any remaining obstacles to the approved use of composite doublers. By focusing on a specific commercial aircraft application - reinforcement of the L-1011 door frame - and encompassing all {open_quotes}cradle-to-grave{close_quotes} tasks such as design, analysis, installation, and inspection, this program is designed to prove the capabilities of composite doublers. This paper reports on a series of structural tests which have been conducted on coupons and subsize test articles. Tension-tension fatigue and residual strength tests attempted to grow engineered flaws in coupons with composite doublers bonded to aluminum skin. Also, structures which modeled key aspects of the door corner installation were subjected to extreme tension, shear, and bending loads. In this manner it was possible to study strain fields in and around the Lockheed-designed composite doubler using realistic aircraft load scenarios and to assess the potential for interply delaminations and disbonds between the aluminum and the laminate. The data acquired was also used to validate finite element models (FEM) and associated Damage Tolerance Analyses.

The purpose of the Data Visualization Project at Sandia Labs is to prototype and evaluate new approaches to the presentation of data for CTBT monitoring applications. The great amount of data expected to be available, and the complex interrelationships in that data, make this a promising area for scientific data visualization techniques. We are developing a powerful and flexible prototyping environment with which to explore these possibilities. A user-friendly graphical user interface (GUI) should be an integral part of any data visualization tools developed. The GUI is necessary to select which data to visualize, and to modify and explore the displays that are the result of data visualization. Using our prototyping environment, we have produced data visualization displays of various kinds of data and have also experimented with different GUIs for controlling the visualization process. We present here an overview of that work, including promising results, lessons learned, and work in progress. To better understand what is needed, we have identified several data processing/analysis scenarios which we think will be important in CTBT monitoring. These scenarios help us identify what types of information we should display (together or in sequence), and help us focus on isolating the underlying goals. Each display we have produced is put in the context of one or more processing scenarios to help explain why and how it could be useful.

The uses of the LON, `Local Operating Network,` developed by Echelon Corporation, Palo Alto, California, has been expanded to handle a number of safeguards applications. A magnetic and vibration sensor pack has been developed to monitor for magnetic fields and vibration. This sensor pack can be attached to any source that generates a magnetic field, such as electrical solenoids or motors, to detect when the source is activated. New network nodes that interface directly with the raw data of Sandia developed radiation sensors, for detecting the presence of radiation sources, have been developed. The capacity of the network has been expanded to allow the transmission of large data sets, specifically the transmission of digital video images from the Sandia-developed-Image Compression and Authentication Module (ICAM).

For the past two years Sandia National Laboratories (SNL) has been involved in developing and installing Remote Monitoring Systems (RMS) at a number of sites around the world. Through the cooperation of the various countries and facilities, it has been possible to collect data on the requirements and performance of these systems that are for monitoring the movement of spent nuclear fuel. The data collected shows that the front end detection method can be a very useful concept to reduce the amount of data that has to be collected and, more importantly, reviewed by inspectors. Spent fuel storage monitoring is a major part of the non-proliferation monitoring that must be done since spent fuel is the by-product of all the power and research reactors worldwide. The movement of spent fuel is easier in many respects to monitor since it always requires protective shielding. This paper will describe a number of the Remote Monitoring Systems that have been installed to monitor spent fuel movement and the resulting decrease in data from the use of a sensor-driven front detection system. The reduction of the data collected and stored is also important to remote monitoring since it decreases the time required to transmit the data to a review site.

The accurate analytical determination of the response of radioactive material transportation packages to the hypothetical puncture accident requires inelastic analysis techniques. Use of this improved analysis method recudes the reliance on empirical and approximate methods to determine the safety for puncture accidents. This paper will discuss how inelastic analysis techniques can be used to determine the stresses, strains and deformations resulting from puncture accidents for thin skin materials with different backing materials. A method will be discussed to assure safety for all of these types of packages.

The safety of the transportation of radioactive materials by road and rail has been well studied and documented. However, the safety of waterborne transportation has received much less attention. Recent highly visible waterborne transportation campaigns have led to DOE and IAEA to focus attention on the safety of this transportation mode. In response, Sandia National Laboratories is conducting a program to establish a method to determine the safety of these shipments. As part of that program the mechanics involved in ship-to-ship collisions are being evaluated to determine the loadings imparted to radioactive material transportation packages during these collisions. This paper will report on the results of these evaluations.

This paper describes the results of an International Monitoring System synergy study using Sandia National Laboratory`s IVSEM (Integrated Verification System Evaluation Model). The study compares individual subsystem performance (seismic, infrasound, radionuclide, and hydroacoustic) with integrated system performance. The integrated system exhibits synergy because different sensor technologies cover different locations; thus, the integrated system covers more locations than can any individual subsystem. Energy and system performance can be further enhanced by allowing mixed technology detection and location.

An enhanced version of NetSim and an expanded supporting database were used to predict the detection and location performances of the International Seismic Monitoring System (ISMS) proposed in Working Paper 330 by the Ad Hoc Committee on a Nuclear Test Ban Treaty who supported the Conference on Disarmament in formulating the system monitoring requirements. The primary goals of this effort were to estimate the levels of 9 performance of the proposed ISMS and to predict the enhancements in location accuracy as would be provided by station and regional calibrations. An estimate of the detection threshold indicates that the primary network alone and in its mature state is capable of detecting a fully coupled 1 kiloton nuclear shot contained in consolidated rock anywhere on the earth. Further, the best detection thresholds appear in central Eurasia and range from 3.25 to 3.5 magnitude units. The threshold estimates were based on a 3P at 99% network detection criterion. Location performance estimates indicated that conventional location methods using regional and station calibrations are capable of achieving location accuracies better than 1000 square kilometers with 90% confidence largely everywhere for events with magnitudes at or above the detection threshold of the primary network. The poorest accuracies primarily appear on islands in the southern oceans and in portions of Antarctica. For events having a magnitude of 4.25 the location accuracy exceeds 100 square kilometers in almost the entire northern hemisphere, over a large portion of Africa, and a small portion of South America. Better accuracies than these are possible at larger event magnitudes. Regional and station calibrations yield net reductions in the elliptical areas of uncertainty by factors better than 6.0 using conventional location methods.

The United States Department of Energy (DOE) uses sensitive or classified parts and material that must be protected and accounted for. We believe there is a need for an automated system that can help protect and monitor these parts and material. In response to this need Sandia National Laboratories (SNL) has developed a real-time personnel and material tracking system called PAMTRAK that has been installed at selected DOE facilities. PAMTRAK safeguards sensitive parts and material by tracking tags worn by personnel and by monitoring sensors attached to the parts or material. This paper describes our goals when designing PAMTRAK, the PAMTRAK system components, our current installations, and the benefits a site can expect when using PAMTRAK. So far PAMTRAK has been installed exclusively at government facilities; however, it is also applicable to private industries that need to protect high value assets. Through government programs such as CRADAs, SBIRs, and other mechanisms, the DOE often works with private industry to promote further development and commercialization of national laboratory developed technologies. SNL supports and welcomes partners and new users of PAMTRAK.

A remote monitoring system (RMS) field trial will be conducted for the International Atomic Energy Agency (IAEA) on highly enriched uranium materials in a vault at the Oak Ridge Y-12 Plant. Remote monitoring technologies are being evaluated to verify their capability to enhance the effectiveness and timeliness of IAEA safeguards in storage facilities while reducing the costs of inspections and burdens on the operator. Phase one of the field trial, which involved proving the satellite transmission of sensor data and safeguards images from a video camera activated by seals and motion sensors installed in the vault, was completed in September 1995. Phase two involves formal testing of the RMS as a tool for use by the IAEA during their tasks of monitoring the storage of nuclear material. The field trial to be completed during early 1997 includes access and item monitoring of nuclear materials in two storage trays. The RMS includes a variety of Sandia, Oak Ridge, and Aquila sensor technologies that provide video monitoring, radiation attribute measurements, and container identification to the on-site data acquisition system (DAS) by way of radio-frequency and Echelon LONWorks networks. The accumulated safeguards information will be transmitted to the IAEA via satellite (COMSAT/RSI) and international telephone lines.

The capture and storage of video images have been major engineering challenges for safeguard and security applications since the video camera provided a method to observe remote operations. The problems of designing reliable video cameras were solved in the early 1980`s with the introduction of the CCD (charged couple device) camera. The first CCD cameras cost in the thousands of dollars but have now been replaced by cameras costing in the hundreds. The remaining problem of storing and viewing video images in both attended and unattended video surveillance systems and remote monitoring systems is being solved by sophisticated digital compression systems. One such system is the PC-104 three card set which is literally a ``video engine`` that can provide power for video storage systems. The use of digital images in surveillance systems makes it possible to develop remote monitoring systems, portable video surveillance units, image review stations, and authenticated camera modules. This paper discusses the video card set and how it can be used in many applications.

There are important differences between the safety principles for nuclear weapons and for nuclear reactors. For example, a principal concern for nuclear weapons is to prevent electrical energy from reaching the nuclear package during accidents produced by crashes, fires, and other hazards, whereas the foremost concern for nuclear reactors is to maintain coolant around the core in the event of certain system failures. Not surprisingly, new methods have had to be developed to assess the risk from nuclear weapons. These include fault tree transformations that accommodate time dependencies, thermal and structural analysis techniques that are fast and unconditionally stable, and parameter sampling methods that incorporate intelligent searching. This paper provides an overview of the new methods for nuclear weapons and compares them with existing methods for nuclear reactors. It also presents a new intelligent searching process for identifying potential nuclear detonation vulnerabilities. The new searching technique runs very rapidly on a workstation and shows promise for providing an accurate assessment of potential vulnerabilities with far fewer physical response calculations than would be required using a standard Monte Carlo sampling procedure.

The US Nuclear Regulatory Commission (USNRC) and the European Commission (EC) have conducted a formal expert judgment elicitation jointly to systematically collect the quantitative information needed to perform consequence uncertainty analyses on a broad set of commercial nuclear power plants. Information from three sets of joint US/European expert panels was collected and processed. Information from the three sets of panels was collected in the following areas: in the phenomenological areas of atmospheric dispersion and deposition, in the areas of ingestion pathways and external dosimetry, and in the areas of health effects and internal dosimetry. This exercise has demonstrated that the uncertainty for particular issues as measured by the ratio of the 95th percentile to the 5th percentile can be extremely large (orders of magnitude), or rather small (factor of two). This information has already been used by many of the experts that were involved in this process in areas other than the consequence uncertainty field. The benefit to the field of radiological consequences is just beginning as the results of this study are published and made available to the consequence community.

Many systems can provide tremendous benefit if operating correctly, produce only an inconvenience if they fail to operate, but have extreme consequences if they are only partially disabled such that they operate erratically or prematurely. In order to assure safety, systems are often tested against the most severe environments and accidents that are considered possible to ensure either safe operation or safe failure. However, it is often the less severe environments which result in the ``worst case accident`` since these are the conditions in which part of the system may be exposed or rendered unpredictable prior to total system failure. Some examples of less severe mechanical, thermal, and electrical environments which may actually be worst case are described as cautions for others in industries with high consequence operations or products.

The Cassini spacecraft is a deep space probe whose mission is to explore the planet Saturn and its moons. Since the spacecraft`s electrical requirements will be supplied by radioisotope thermoelectric generators (RTGs), the spacecraft designers and mission planners must assure that potential accidents involving the spacecraft do not pose significant human risk. The Cassini risk analysis team is seeking to perform a quantitative uncertainty analysis as a part of the overall mission risk assessment program. This paper describes the uncertainty analysis methodology to be used for the Cassini mission and compares it to the methods that were originally developed for evaluation of commercial nuclear power reactors.

Sandia National Laboratories has assembled an interdisciplinary team to explore the applicability of probabilistic logic modeling (PLM) techniques to model network reliability for a wide variety of communications network architectures. The authors have found that the reliability and failure modes of current generation network technologies can be effectively modeled using fault tree PLM techniques. They have developed a ``plug-and-play`` fault tree analysis methodology that can be used to model connectivity and the provision of network services in a wide variety of current generation network architectures. They have also developed an efficient search algorithm that can be used to determine the minimal cut sets of an arbitrarily-interconnected (non-hierarchical) network without the construction of a fault tree model. This paper provides an overview of these modeling techniques and describes how they are applied to networks that exhibit hybrid network structures (i.e., a network in which some areas are hierarchical and some areas are not hierarchical).