Publications

Recently, significant progress has been made in using finite-difference analysis cod es to simulate the responses of complex structures due to direct lightning. Advances have been made in interfacing a finite-difference code with commercial computer aided design tools, in suppressing a weak instability associated with the thin-wire algorithm for modeling conductors much smaller than a cell size, and in visualizing the results with color movies. Preliminary comparisons between the results of the finite-difference code and the results obtained during a recent rocket-triggered lightning test are also presented.

The US Department of Energy`s Nuclear Plant Lifetime Improvement Program is investigating the use of prognostic monitoring to extend the operational lifetime of specific equipment. Benefits of these achievements will include safer and more reliable nuclear Plants, reduced maintenance costs, and increased lifetime of equipment. This report describes the development and application of a monitoring system designed to predict starting system performance of Emergency Diesel Generators. The monitor system is evaluated on two different engines, each using a different method of starting.

Portable acoustic wave sensor (PAWS) systems are being developed for real-time, on-line monitoring of volatile organic compounds (VOC`s). These systems are built around acoustic wave (SAW) devices coated with viscoelastic polymers. Two independent responses of the SAW sensor, wave velocity and wave attenuation, are measured to provide information about the chemical species sorbed by the coating. Rapid, reversible detection of gas phase volatile organics has been demonstrated for process monitoring and waste minimization in environmentally conscious manufacturing (ECM) applications and for documenting contaminant concentrations in remediation efforts.

The Hard Rock Penetration program is developing technology to reduce the costs of drilling and completing geothermal wells. Current projects include: lost circulation control, rock penetration mechanics, instrumentation, and industry/DOE cost shared projects of the Geothermal Drilling organization. Last year, a number of accomplishments were achieved in each of these areas. A new flow meter being developed to accurately measure drilling fluid outflow was tested extensively during Long Valley drilling. Results show that this meter is rugged, reliable, and can provide useful measurements of small differences in fluid inflow and outflow rates. By providing early indications of fluid gain or loss, improved control of blow-out and lost circulation problems during geothermal drilling can be expected. In the area of downhole tools for lost circulation control, the concept of a downhole injector for injecting a two-component, fast-setting cementitious mud was developed. DOE filed a patent application for this concept during FY 91. The design criteria for a high-temperature potassium, uranium, thorium logging tool featuring a downhole data storage computer were established, and a request for proposals was submitted to tool development companies. The fundamental theory of acoustic telemetry in drill strings was significantly advanced through field experimentation and analysis. A new understanding of energy loss mechanisms was developed.

Sandia National Laboratories (SNL) is in the final stages of developing a Universal Authenticated Item Monitoring System (AIMS). When completed, AIMS will provide applicable agencies in the US government, and those in the International arena, with a secure and convenient method of monitoring the physical status of selected items. The benefit derived from this development activity will be the commercial availability of an item monitoring system with the capability for ``quick set-up`` monitoring, as well as long-term unattended monitoring. The AIMS includes a variety of sensors, a robust and authenticated radio frequency (RF) communication link, a Receiver Processing Unit (RPU), and an inspector-friendly personal computer (PC) interface for collecting, sorting, viewing and archiving pertinent event histories. The system will provide the capability to monitor selected items in a real-time mode, a remotely interrogated mode, and a stand-alone, unattended data collection mode. The sensor suite under development includes advanced motion sensors, interior volumetric intrusion sensors, Re-usable, In-situ Verifiable Authenticated (RIVA) fiber-optic seal sensors, generic utility sensors (to accommodate contact closure inputs), and radiation and environmental sensors. A new generation authentication algorithm recently has been developed that provides a high degree of system security 121. The AIMS has potential safeguards applications in the areas of arms control and treaty verification military asset control, International Atomic Energy Agency (IAEA) and Euratom safeguards verification activities, as well as domestic nuclear safeguard activities. Commercial applications could include high-value inventory control and security systems. This paper describes the second-generation AIMS along with its recently expanded sensor suite and enhanced data collection capabilities.

In a joint effort conducted by Sandia National Laboratories, the International Atomic Energy Agency (IAEA), and the Japan Atomic Energy Research Institute (JAERI), an authentication system has been installed at the Fast Critical Assembly (FCA) facility in Tokai-mura, Japan. The purpose of this authentication system is to provide the IAEA with an independent means of authenticating the operator-provided Advanced Containment and Survellance (AC/S) system already in place at the facility. Authentication Controllers were installed at the AC/S Portal Monkor and Penetration Monitor to collect data and to randomly test sensor functions between IAEA inspections. During each inspection the authentication data is collected with an Inspector`s portable computer and printed for comparison to the data recorded by the AC/S system. Installation of the authentication equipment took place in November 1991 and a three-month field test began in December 1991. This paper will describe the authentication system, the operator interface, and the preliminary results of the field tests.

A public-key Treaty Data Authentication Module (TDAM) based on the National Institute of Standards and Technology (NIST) Digital Signature Standard (DSS) has been developed to support treaty verification systems. The TDAM utilizes the Motorola DSP56001 Digital Signal Processor as a coprocessor and supports both the STD Bus and PC-AT Bus platforms. The TDAM is embedded within an Authenticated Data Communication Subsystem (ADCS) which provides transparent data authentication and communications, thereby concealing the details of securely authenticating and communicating compliance data and commands. The TDAM has been designed according to the NIST security guidelines for cryptographic modules. Public-key data authentication is important for support of both bilateral and multi-lateral treaties. 8 refs.

Parametric weld size predictions, in which weld size and shape are predicted given a knowledge of material and process parameters, offer a great deal of benefit to the welding engineer. This is so because the technique promises to replace expensive and time-consuming lab or shop activity followed by destructive examination with simple numeric or nomographic calculations. The work to be presented here uses a simple two-dimensional axisymmetric spot-on-plate computer simulation in which thermal diffusivity vs temperature is varied.

The change in the world military posture and the reduction in military personnel require the flexible and rapid deployment of priority defense assets. Air Force security personnel and operators must maintain the ability to secure these deployed assets and receive advanced warning of threats. The Air Force will meet this need through the Dispersed Integrated Security System (DISS). The system will be rapidly deployable, relocatable, support mission flexibility, and be capable of intrusion detection, area and alarm display, night assessment, and wireless data communications. Wireless links, as obtained through radio, are quickly deployed and cost less than their hardwire counterpart when labor cost and equipment reuse are considered. DISS communications systems will be flexible and have broad application. By integrating commercial components and using menu-driven setup procedures, low cost, versatile, easy-to-use communication systems will be implemented to meet Air Force user requirements and provide desired capabilities.

It has long been United States Government (USG) policy to actively support nuclear nonproliferation efforts, as evinced in the 1970 US ratification of the Nuclear I Nonproliferation Treaty (NPT) and the 1978 US Voluntary Treaty with the IAEA (INFCIRC/288). Under INFCIRC 288, US facilities without direct national security involvement are eligible for International Atomic Energy Agency (IAEA) safeguards. Throughout the past decade, the IAEA has selected one or two US facilities for implementation of IAEA safeguards at a given time. The facilities selected have generally been those which allowed the IAEA to test new or advanced safeguards techniques, facilities which were prototypical or similar to other nuclear facilities which they will have to safeguard in other countries, or facilities which have been engaged in international commerce in nuclear materials. The US is now actively addressing issues of the interim and permanent disposal of nuclear waste and spent nuclear fuel -- the back end of the open US nuclear fuel cycle. The Nuclear Waste Policy Act (NWPA) of 1982 designated the US Department of Energy (DOE) to be responsible for the long term storage and isolation from the biosphere of spent nuclear fuel (SNF) and high-level waste (HLW) and created the DOE Office of Civilian Radioactive Waste Management (OCRWM) to develop, construct, and manage the Civilian Radioactive Waste Management System (CRWMS). Refinements to the NWPA occurred in 1987 in the Nuclear Waste Policy Amendments Act of 1987. CRWMS facilities will be eligible for IAEA safeguards. They are likely to be selected because they will be among the first SNF and HLW disposal operations worldwide.

As the US nuclear stockpile is reduced, large numbers of nuclear components must be placed in storage. The necessity for periodic inventories of these components as well as the act of placement of the components in storage areas could result in increased radiation exposure to operations personnel. The use of robotics can significantly reduce or even eliminate such exposure. An automated system is being designed in a project at Sandia Laboratories to allow an operator to remotely stack and retrieve component containers in storage areas using a robotic loader and a portable control console. The operator need not enter the storage area. Operator commands for the loader would be implemented through a supervisory architecture that would insure that the loader did not violate safety constraints. Individual aspects of the loader`s activities would be automated to reduce possible operator errors for many repetitive tasks. The loader will be outfitted with appropriate sensors so that the supervisory controller can enforce safe operations. The system will be configured so that monitoring of components for accountability can be accomplished.

To achieve the goal of remediating waste sites throughout its complex and of bringing its facilities into full compliance by the year 2019, the DOE has established the Office of Environmental Restoration and Waste Management (E). Within E, the Office of Technology Development (OTD) has been created to develop technologies that will support DOE`s cleanup goal. The OTD is accelerating remediation technology application by leveraging the expenditure of available funds through international technology development and demonstration projects. These projects will address EM`s environmental restoration and waste management needs. For this reason, the OTD has created the International Technology Exchange Program (ITEP) whose primary objective is to effect collaboration among governments, industries, and educational institutions to identify worldwide technologies suitable for this purpose. These technologies should also meet US commercial needs. The ITEP will also serve as a mechanism for transferring technologies developed under DOE sponsorship to US industry for ultimate application in the international arena.

Short communication.

The US Department of Energy (DOE) has committed to the remediation of waste sites throughout its complex, and has recognized that it can accelerate its technology development efforts and leverage the expenditure of available funds through an international cooperation among government entities, private industry, and educational institutions. To support the technology transfer of environmental information, the DOE has sponsored the development of EnviroTRADE - an international information system that will facilitate the exchange of environmental restoration and waste management technologies worldwide. During DOE`s fiscal year 1992, a beta prototype is being developed by Sandia National Laboratories (SNL). During fiscal year 1993 and beyond, the full system will be developed and networked among international users. The system will contain profiles on both environmental restoration/waste management needs and foreign/domestic technologies. Users will be able to identify matches between worldwide needs and available or emerging technologies. Where matches between needs and existing technologies are not found, the system will identify the potential for development of new and innovative technologies to address environmental problems. EnviroTRADE will also provide general information on international environmental restoration and waste management organizations, sites, activities, and contacts.

As part of the update of the Safety analysis Report (SAR) for the Annular Core Research Reactor (ACRR), operational limiting events under the category of inadvertent withdrawal of an experiment while at power or during a power pulse were determined to be the most limiting event(s) for this reactor. This report provides a summary of the assumptions, modeling, and results in evaluation of: Reactivity and thermal hydraulics analysis to determine the amount of fuel melt or fuel damage ratios; The reactor inventories following the limiting event; A literature review of post NUREG-0772 release fraction experiment results on severe fuel damages; Decontamination factors due to in-pool transport; and In-building transport modeling and building source term analysis.

As part of the Direct Optical Initiation (DOI) program, an assessment of the possibility of introducing lightning energy into an exclusion region via an Optical Barrier Feedthrough (OBF) is being carried out. One postulated penetration mechanism is the tracking of current past the OBF on the surface of the dielectric optical fiber itself. During September and October of 1991, a series of tests was conducted on a closed metallic cylindrical test object representing the electrical exclusion region of a weapon. Median-level (30-kA) and severe (200-kA) simulated lightning return strokes, singly, doubly, and in combination with a moderate continuing current, were attached directly to the exterior portion of a fiber optic cable, which penetrated through a hole of controlled size into the interior of the exclusion region. The thickness of the barrier surrounding the hole was 0.06 in. Attempts were made to measure any conducted current flowing on the fiber at distances of 1 and 4 inches from the interior surface of the stainless steel top of the cylinder. Test parameter variations included diameter of the penetration hole (475 and 500 microns), length of the exterior portion of the cable and whether or not its jacket was present, and the applied test currents. It is concluded that no signal above measurement noise was recorded on any of the data shots that made up the test series. Measurement resolution was of the order of several amperes. Based on the highest recorded response of 8.5 A, corresponding to a 200-kA input, the OBF can be characterized by a direct-strike lightning attenuation factor of approximately 5 {times} lO{sup {minus}5} or better. Based on the more typically observed noise level of a few amps, the attenuation is commensurately greater.

Detailed mineralogical studies of the matrix and fracture-fill materials of a large number of samples from the Rustler Formation have been carried out using x-ray diffraction, high-resolution transmission electron microscopy, electron microprobe analysis, x-ray fluorescence, and atomic absorption spectrophotometry. These analyses indicate the presence of four clay minerals: interstratified chlorite/saponite, illite, chlorite, and serpentine. Corrensite (regularly stratified chlorite/saponite) is the dominant clay mineral in samples from the Culebra dolomite and two shale layers of the lower unnamed member of the Rustler Formation. Within other layers of the Rustler Formation, disordered mixed chlorite/saponite is usually the most abundant clay mineral. Studies of the morphology and composition of clay crystallites suggest that the corrensite was formed by the alteration of detrital dioctahedral smectite in magnesium-rich pore fluids during early diagenesis of the Rustler Formation. This study provides initial estimates of the abundance and nature of the clay minerals in the Culebra dolomite in the vicinity of the Waste Isolation Pilot Plant.

This document describes an automated, data acquisition system designed to test the performance of remote badge readers. These readers interrogate badges by transmitting and receiving energy. The performance of such readers is statistical and can be affected by geometrical and environmental variables. Characterization of performance, therefore, requires multiple measurements while the known variables are controlled. Automation makes this a practical task.

The contribution of essential service water (ESW) system failure to core damage frequency has long been a concern of the NRC. The objective of this study is to assess the safety significance of the loss of ESW systems in LWRs relative to core damage frequency (CDF) and perform a limited value/impact analysis of potential modifications to solve ESW vulnerabilities using a prototypical (pilot) plant. Previous studies indicate that service water systems contribute from < 1% to 65% of the total internal CDF. For the pilot plant analyzed, common ESW vulnerabilities are failure of standby service water pumps to start, backflow through check valves for cross-tied pumps, and failure of normally closed isolation valves in diesel generator cooling loops to open on demand. For the potential modifications evaluated for the pilot plant, the results showed that they could reduce the CDF by as much as 33 percent. However, the dollars per person REM measures resulting from various groups of these modifications significantly exceeded the current criteria of $1000. The results, since they only apply to the prot plant, are not typical of all LWRs. Due to the importance of service water to CDF and the plant specific nature of ESW systems, there could be plants for which there would be cost-effective modifications. Additional analysis would be required to identify them.

The low field (E{congruent}2kV/cm) Metal Oxide Varistor (MOV) is a voltage regulation device. This report describes a technique for performing DC characteristic measurements on a MOV. The varistor is in the feedback loop of a high voltage operational amplifier. A current source forces a staircase current waveform through a MOV. An operational amplifier provides the required applied voltage to maintain the desired values of current through the varistor. The current values change at a maximum rate of 33.3 readings per second and a high speed voltmeter measures the varistor voltage. The maximum available current and voltage at present are 5 mA and 10 kV respectively. Examples of its use are with data from the MC3596 and XMC4317.

The performance Assessment (PA) Department of Sandia National Laboratories annually compares the Waste Isolation Pilot Plant (WIPP) with the Environmental Protection Agency`s Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, 40 CFR 191. To assist the analyst in these comparisons the PA Department developed CAMCON, the Compliance Assessment Methodology Controller, which creates an analysis system out of the diverse computer modeling codes needed for this interdisciplinary comparison. This reference manual describes the use of most of the codes in the CAMCON system that an analyst may use when performing the PA comparisons. Although some of the codes included in CAMCON have their own user`s guide, this manual summarizes these guides as well to provide the user with one comprehensive document of the codes within the CAMCON system.

Site-characterization, data interpretation, and modeling efforts have been conducted for the Waste Isolation Pilot Plant (WIPP), a US Department of Energy facility, in southeastern New Mexico as part of the evaluation of the suitability of the bedded salt of the Salado Formation for isolation of defense transuranic wastes. The Culebra Dolomite Member of the Rustler Formation is the most transmissive and laterally continuous hydrogeologic unit above the Salado Formation and is considered to be the principal offsite pathway for radionuclide transport in the subsurface, should a breach of the repository occur. The potential importance of this offsite pathway has motivated the design and implementation of tests to characterize the solute-transport properties of the Culebra dolomite. On a regional scale, long-term pumping tests have been performed and analyzed to provide information concerning the broad hydrologic flow characteristics of the Culebra dolomite. At the local (or hydropad) scale, conservative (i.e., nonreactive) tracer tests have been performed to characterize the solute-transport properties of the Culebra dolomite. The tracer-test interpretations presented in this report were performed by INTERA Inc. under contract to SNL. The tracer tests and their interpretation provide data for use in performance-assessment calculations of site suitability for waste isolation. In particular, transport parameters determined from these tests are used as input for offsite solute-transport simulations.

An essential part of the license application for a geologic repository will be the demonstration of compliance with the standards set by the Environmental Protection Agency. The performance assessments that produce the demonstration must rely on models of various levels of detail. The most detailed of these models are needed for understanding thoroughly the complex physical and chemical processes affecting the behavior of the system. For studying the behavior of major components of the system, less detailed models are often useful. For predicting the behavior of the total system, models of a third kind may be needed. These models must cover all the important processes that contribute to the behavior of the system, because they must estimate the behavior under all significant conditions for 10,000 years. In addition, however, computer codes that embody these models must calculate very rapidly because of the EPA standard`s requirement for probabilistic estimates, which will be produced by sampling thousands of times from probability distributions of parameters. For this reason, the total-system models must be less complex than the detailed-process and subsystem models. The total-system performance is evaluated through modeling of the following components: Radionuclide release from the engineered-barrier system. Fluid flow in the geologic units. Radionuclide transport to the accessible environment. Radionuclide release to the accessible environment and dose to man.

A sensor-based intelligent control system is described that utilizes a multiple degree-of-freedom robotic system for the automated remote manipulation and precision docking of large payloads such as waste canisters. Computer vision and ultrasonic proximity sensing are used to control the automated precision docking of a large object with a passive target cavity. Real-time sensor processing and model-based analysis are used to control payload position to a precision of {plus_minus} 0.5 millimeter.

Historical and projected inventories of spent fuel from commercial light-water nuclear reactors exhibit diverse decay characteristics and ages. This report summarizes a preliminary reexamination of a method for determining equivalent thermal loads for the range of spent fuel expected at a potential underground repository. The method, known at the Equivalent Energy Density (EED) concept, bases its equivalence criteria on the assumption that a given waste will produce worst-case thermomechanical effects equal to worst-case thermomechanical effects produced by a baseline waste, provided that the thermal energy deposited in the host rock over a specified deposition period is the same for both waste descriptions. To test this assumption, temperature histories at representative locations within the host rock were calculated using layouts defined by the EED concept and four deposition periods (20, 50, 100, and 300 years). It was found that the peak temperatures at near-field locations were best matched by the shorter deposition periods of 20 and 50 years. However, due to the sensitivity of the near-field environment to short-term canister-to-canister interactions, caution,should be used when choosing a near-field deposition period. At the location chosen to represent the far-field, a 300-year deposition period provided reasonable correspondence of peak temperature responses for all waste descriptions examined.