Publications

This report describes the components and installation of the Oxygen Deficiency Monitor System (ODMS) at the Simulation Technology Laboratory (STL) at Sandia National Laboratories. The ODMS presently monitors the oxygen concentration of the ambient air in the lower levels of the laboratory where air circulation may be insufficient to disperse gases that may settle and accumulate creating an oxygen-deficient environment. The intent of this report is to provide a general introduction to the system for personnel involved in the maintenance and modifications of the system and may be useful to people interested in installing a similar system. This will report describe the hardware components, installation considerations, operation, and maintenance of the system. 6 refs., 5 figs.

The literature is reviewed on the amount and the characteristics of particulate material (crud), that is deposited on Light Water Reactor (LWR) fuel rods and assemblies. Currently available data on crud composition, specific activity, spallation mechanisms, potential environmental release, and particle size distributions is considered. In addition, literature that pertains to the possible impact of crud on repository operations is surveyed. This report consists of rather extensive excerpts from the published literature on crud that may have a bearing on repository risk assessment. Commentary on the possible effects of crud on repository operations and the applicability of available crud information to repository risk analyses is included. In addition, estimates are made of the quantity of crud that might be available for release during the different phases of repository operations. Using these estimates, the total effective dose equivalent is determined at several distances from a release point.

This 1989 report contains monitoring data from routine radiological and nonradiological environmental surveillance activities. Summaries of significant environmental compliance programs in progress such as National Environmental Policy Act documentation, environmental permits, environmental restoration, and various waste management programs for Sandia National Laboratories in Albuquerque (SNL, Albuquerque) are included. The maximum offsite dose impact was calculated to be 8.8 {times} 10{sup {minus}4} mrem. The total Albuquerque population received a collective dose of 0.097 person-rem during 1989 from SNL, Albuquerque, operations. As in the previous year, SNL, Albuquerque, operations in 1989 had no adverse impact on the general public or on the environment. 46 refs., 20 figs., 31 tabs.

This report summarizes the environmental surveillance activities conducted by Environmental Protection Agency (EPA) and Reynolds Electrical and Engineering Company (REECo) for the Tonopah Test Range (TTR) operated by Sandia National Laboratories (SNL). Other environmental compliance programs such as National Environmental Policy Act of 1969 (NEPA), environmental permits, environmental restoration, and waste management programs are also included. The maximum offsite dose impact from 1989 operations was 8.7 {times} 10{sup {minus}4} mrem as a result of an unusual occurrence. The population received a collective dose of 1.2 {times} 10{sup {minus}5} person-rem from this incidence, while the same populations received 4.94 person-rem from natural background radiation. The 1989 SNL, TTR operations had no adverse impact on the general public or the environment. 18 refs., 2 figs., 14 tabs.

Drillholes H-11b1, H-11b2, and H-11b3 were drilled from August to December 1983 for site characterization and hydrologic studies of the Culebra Dolomite Member of the Upper Permian Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. In October 1984, the three wells were subjected to a series of pumping tests designed to develop the wells, provide information on hydraulic communication between the wells, provide hydraulic properties information, and to obtain water samples for quality of water measurements. Based on these tests, it was determined that this location would provide an excellent pad to conduct a convergent-flow non-sorbing tracer test in the Culebra dolomite. In 1988, a fourth hole (H-11b4) was drilled at this complex to provide a tracer-injection hole for the H-11 convergent-flow tracer test and to provide an additional point at which the hydraulic response of the Culebra H-11 multipad pumping test could be monitored. A suite of geophysical logs was run on the drillholes and was used to identify different lithologies and aided in interpretation of the hydraulic tests. 4 refs., 6 figs., 6 tabs.

A computer model for simulating the explosive dispersal of a fuel agent in the far-field regime is described and is applied to a wide variety of initial conditions to judge their effect upon the resulting fuel/air cloud. This work was directed toward modeling the dispersal process associated with Fuel-Air-Explosives devices. The far-field dispersal regime is taken to be that time after the initial burster charge detonation in which the shock forces no longer dominate the flow field and initial canister and fuel mass breakup has occurred. The model was applied to a low vapor pressure fuel, a high vapor pressure fuel and a solid fuel. A strong dependence of the final cloud characteristics upon the initial droplet size distribution was demonstrated. The predicted fuel-air clouds were highly non-uniform in concentration. 18 refs., 86 figs., 4 tabs.

The Vindicator ETW-250 taut wire system combines a physical taut wire barrier with an intrusion detection sensor network. The sensor wires deter and/or slow physical entry into protected areas. The sensors themselves generate an alarm if the sensor wires are pulled, spread, cut, or climbed on. This physical motion is converted into an electrical waveform that is analyzed by the processor. The processor then determines if this motion is within the pre-programmed parameters. If it is not, an alarm is generated through a relay back to the monitoring station. Small changes, such as those caused by temperature, are rejected. Installation and testing are described.

Containment and Surveillance (C/S) equipment, which is used in international safeguards applications, is normally expected to operate unattended within a facility in a host country for extended periods of time. To ensure that this equipment consistently provides high-quality data, the equipment used to ensure the data's integrity must be highly reliable and tamper-resistant. Although designed specifically for use by the International Atomic Energy Agency to comply with the Non-Proliferation Treaty, the equipment has potential applications for both bilateral and multilateral verification schemes for other treaties. This report describes C/S equipment that has been developed by Sandia National Laboratories, and discusses its potential applications. This equipment includes surveillance equipment, seals, monitoring equipment, and authentication equipment. 16 refs., 20 figs.

Waste Isolation Pilot Plant (WIPP) sealing program results are embodied in the initial seal system strategy and reference design. The design provides a common basis for calculations and analyses so that results can be compared directly. The sealing strategy combines both long- and short-term seal components. Crushed salt is the principal long-term barrier to fluid flow. Short-term seal components are used until creep consolidation is sufficient. Concretes developed specifically for WIPP seals and a swelling clay material that exhibits low permeability to WIPP groundwater and brine have been chosen for the short-term components. A body of evidence exists showing the stability of these materials for the length of time they are required to function. Reference designs are described and drawings are shown for each of the principal multi-component seals. Confidence in the sealing strategy and the reference designs resulted from a combination of laboratory tests, numerical modeling, and in situ demonstrations. The sealing strategy, materials, and designs for the WIPP repository are consistent with the concepts and designs proposed previously for other national and international waste management programs. Past accomplishments and planned activities in the sealing program will produce a detailed conceptual design for the seal system and a seal system performance model. 48 refs., 11 figs., 6 tabs.

In the course of communication circuit design at Sandia National Laboratories, a set of communication symbols was created to aid, and hopefully standardize, the design process. These symbols, which allow the designer to build a circuit using black boxes, simplify circuit design and documentation. They also provide a standard set to help minimize interpretation problems among circuit designers. The symbols can be used to represent various devices in a circuit, such as modems, computers, terminals, encryption devices, converters, etc. When using these symbols to design communication circuits, the contours of each symbol show which devices interface together. Mismatch device contours indicate the need for another element (such as a null modem) between the two devices. In addition, the propagation of clock, data, and control signals through the circuit can be represented. Clocking modes on synchronous components (modems, multiplexers, etc.) and signal line crossovers can also be determined from the drawings during the design process. 30 figs.

A series of test has evaluated the current-carrying characteristics of several proposed detonator strong safety link (DSSL) drive cables to conduct current into an electrically simulated radiation case enclosure. The drive cables tested included a dielectric cable made up of either one or two braided Kevlar threads in a polysulfone sleeve, an existing DSSL conductive drive cable similar to a bicycle shift cable, with and without an external ground-strap diversion feature, and the flex circuit hook assembly used for DSSL instrumentation purposes. Each of the test samples was connected to a 200-kV, 30-kA Marx generator and terminated inside an electrically simulated radiation case enclosure. Two lengths of drive cables (4 and 13 in.) within the simulated radiation case were tested for each type. The results indicate that the conductive drive cables without an external short-circuit diversion feature conducted about 5 to 9 times as much current into the simulated radiation case as either the dielectric drive cables or the conductive drive cables with an external short-circuit feature. Surprisingly, the flex circuit hook assemblies, both the short and long cables, conducted nearly 100% of the available current into the simulated radiation case enclosure. The next series of experiments will repeat the tests at the SNL Lightning Facility in order to scale the results up to the maximum lightning threat levels of 200 kA. 18 figs., 1 tab.

The solderability of 60Sn40Pb solder on Kovar was examined as a function of surface-cleaning procedure, flux, and solder-bath temperature. Organic-acid fluxes were more effective at lowering the contact angle than was a mildly activated, rosin-based (RMA) flux on chemically etched Kovar. The contact angles were as low as 29{degree} {plus minus} 5{degree} as compared to 61{degree} {plus minus} 11{degree}, respectively. Varying the solder temperature through the range of 215{degree}C to 288{degree}C caused an insignificant change in the contact angle for the RMA flux and a decrease of the contact angle for a candidate water-based, organic-acid flux. The dilution strength of the flux and the elapsed cleaning time significantly influenced the solder-flux interfacial tension, {sub {gamma}LF}. T-peel strengths of Kovar-60Sn40Pb-OFHC copper joints had a low correlation with the contact angle derived from the solderability experiments. The results of the solderability tests and the T-peel mechanical tests, and subsequence microanalysis of the as-soldered and T-peel samples revealed that the best results for the RMA flux were achieved by using an electropolishing procedure and a solder temperature of 240{degree}C to 260{degree}C. A relatively low contact angle of 31{degree} {plus minus} 2{degree} was observed, with no evidence of cracking or thick-film intermetallic formation at the Kovar-solder interface. T-peel strengths were nominally 9.4{degree} {plus minus} 0.5 {times} 10{sup 6} dyn/cm. 21 refs., 36 figs., 11 tabs.

Parachute system performance issues such a turnover and wake recontact may be strongly influenced by velocities induced by the wake of the delivering aircraft, especially if the aircraft is maneuvering at the time of parachute deployment. The effect of the aircraft on the parachute system is a function of the aircraft size, weight, and flight path. In order to provide experimental data for validation of a computer code to predict aircraft wake velocities, a test was conducted in the NASA 14 {times} 22 ft wind tunnel using a 5.78% model of the B-1B strategic bomber. The model was strut mounted through the top of its fuselage by a mechanism which was capable of pitching the model at moderate rates. In this series of tests, the aircraft was pitched at 10{degree}/sec from a cruise angle of attack of 5.3{degree} to an angle of attack of 11{degree} in order to simulate a 2.2g pullup. Data were also taken for the subsequent pitch down sequence back to the cruise angle of attack. Instantaneous streamwise and vertical velocities were measured in the wake at a number of points using a hot wire anemometer. These data have been reduced to the form of downwash coefficients which are a function of the aircraft angle of attack time-history. Unsteady effects are accounted for by use of a wake convection lag-time correlation. 12 refs., 59 figs., 4 tabs.

This report presents the concept of formalizing the elicitation and use of expert judgment in the performance assessment of high-level radioactive waste (HLW) repositories in deep geologic formations. The report begins with a discussion of characteristics (advantages and disadvantages) of formalizing expert judgment examples of previous uses of expert judgment in radioactive waste programs, criteria that can assist in deciding when to formalize expert judgment, and the relationship of formal use of expert judgment to data collection and modeling. The current state of the art with respect to the elicitation, use, and communication of formal expert judgment is presented. The report concludes with a discussion on potential applications of formal expert judgment in performance assessment of HLW repositories. 93 refs.

As part of a Department of Energy/Commission of European Communities (DOE/CEC) cooperative program, Sandia National Laboratories was asked to develop a portable ultrasonic seal pattern reading system. The system consists of a data acquisition box (DAB), a mechanical reading head, and a portable IBM-compatible PC linked to the DAB by a serial RS-232C communication link. This manual focuses on the DAB subsystem. 8 refs., 13 figs., 8 tabs.

MCPRAM (Monte Carlo PReprocessor for AMEER), a computer program that uses Monte Carlo techniques to create an input file for the AMEER trajectory code, has been developed for the Sandia National Laboratories VAX and Cray computers. Users can select the number of trajectories to compute, which AMEER variables to investigate, and the type of probability distribution for each variable. Any legal AMEER input variable can be investigated anywhere in the input run stream with either a normal, uniform, or Rayleigh distribution. Users also have the option to use covariance matrices for the investigation of certain correlated variables such as booster pre-reentry errors and wind, axial force, and atmospheric models. In conjunction with MCPRAM, AMEER was modified to include the variables introduced by the covariance matrices and to include provisions for six types of fuze models. The new fuze models and the new AMEER variables are described in this report.

The purpose of this report is to summarize for the record the objectives, planning, progress, and documentation of excavating Brine Inflow Room Q and implementing an initial set of Room Q tests. The Room Q tests were designed primarily to test the scale-up accuracy of the current brine inflow model by providing data on brine flow from the host rock salt to a large-scale excavation in the Waste Isolation Pilot Plant (WIPP). Data from these tests will also be used to reduce uncertainties in flow parameters and evaluate proposed mechanistic models. Room Q was excavated with a tunnel boring machine. The initial tests were implemented to measure brine flow parameters and room closure. Pore pressure, permeability, and brine inflow were measured with 15 tools emplaced in boreholes above, below, and on the north side of the room at a station 75 feet into the host rock from the entrance to the room. These measurements were made before, during, and after Room Q was bored to obtain data on the responses in the host rock to the boring process. Closure measurements were started almost immediately after excavation progressed past each measurement station. The designs, timing, sequence, procedures, and as-built records for these tests were documented in Sandia National Laboratories WIPP Quality Assurance files and Westinghouse WIPP Engineering records. 21 refs., 5 figs., 5 tabs.

CTH is a software system under development at Sandia National Laboratories (SNL) to model multidimensional, multi-material, large deformation, strong shock wave physics. One-dimensional rectilinear, cylindrical, and spherical meshes; two-dimensional rectangular, and cylindrical meshes; and three-dimensional rectangular meshes are currently available. A two-step Eulerian solution scheme is used with these meshes. The first step is a Lagrangian step in which the cells distort to follow the material motion. The second step is a remesh step where the distorted cells are mapped back to the original Eulerian mesh. CTH has several thermodynamic models that are used for simulating strong shock, large deformation events. Both tabular and analytic equations of state are available. CTH can model material strength, high explosive detonation, fracture, and motion of fragments smaller than a computational cell. The material strength model is elastic perfectly plastic with thermal softening. A programmed burn model is available for computing the thermodynamic properties of explosive detonation. The Jones-Wilkins-Lee equation of state is available for modelling high explosive reaction products. Fracture can be initiated based on pressure or principle stress. A special model is available for moving fragments smaller than a computational cell with the correct statistical velocity. 7 refs.

A description is given of Sandia's CONCEPT-90 module, which represents a novel type of point-focus photovoltaic concentrator module designed for improved safety, reliability, and performance, and for ease of component fabrication and module assembly. These improvements will combine to decrease the cost of electricity produced by this type of concentrator module. Unique features of the CONCEPT-90 module include encapsulated cell assemblies, simple flat components, and integral use of plastics. The first prototype of this module has been made using back-contact silicon concentrator cells and refractive secondary optical elements. The first prototype module is described, and results from outdoor tests are presented.

The Software Utilities Package for the Engineering Sciences (SUPES) is a collection of subprograms which perform frequently used non- numerical services for the engineering applications programmer. The three functional categories of SUPES are: (1) input command parsing, (2) dynamic memory management, and (3) system dependent utilities. The subprograms in categories one and two are written in standard FORTRAN-77, while the subprograms in category three are written to provide a standardized FORTRAN interface to several system dependent features. 2 refs.

Magnet configurations are found that limit the 6-MeV electrons threatening satellite electronics to <1% of the incident flux. Successful configurations of permanent magnets and electromagnets require magnetic energies of {approximately}8 to 12 kJ to protect each liter of electronics volume. The fundamental strength of materials leads to a required minimum mass of {approximately}48 to 64 kg/liter to support the magnetic pressure. With the electronics requiring {approximately}5 liters, several hundred kilograms are needed for this support. Except for protecting small apertures, magnetic shielding provides little, if any, advantage over that obtained by coating with an equivalent mass using traditional methods. 7 refs., 9 figs., 1 tab.

Until recently, hydrologic characterization in closed sections of boreholes at the Waste Isolation Pilot Plant (WIPP) has relied on measurements of pressure and temperature to establish the permeability of the host geological formations. There were no provisions for monitoring tool compliance and salt creep resulting from borehole closure. The new permeability test tool used to characterize the WIPP underground facility has been equipped with a series of sensors to measure the movement of the tool with respect to the borehole and borehole wall movement. A FORTRAN program can interpret the output data from each test and calculate the change in borehole radius, test zone length, and test zone volume. These values provide a correlation of fluid compressibility and tool compliance with the permeability results derived from the test data. 4 figs., 3 tabs.

The capabilities of a versatile Nd:YAG pulsed-laser system developed at Sandia National Laboratories for solar cell processing applications is described. The results of statistically based, multifactor experiments used to characterize the influence of laser-system process variables on patterns produced in silicon wafers and silicon-oxide layers are presented, and an initial assessment of laser-grooved solar cell processing conditions is given.

AlGaAs/GaAs solar cells are typically characterized as having relatively high interface recombination velocities at the heteroface. Some of the factors influencing the design of solar cell window layers are examined, and the effect of substituting InAlAs/GaAs superlattice alloys and InAlAs bulk alloys in place of AlGaAs is considered. Potential advantages are reduced surface recombination at the heterojunction, reduced thermionic emission into the window layer, thinner window layers, and reduced absorption in the window layer. Theoretical models predict a lower effective surface recombination velocity and a smaller acceptor activation energy for superlattice alloys. Experimental absorption data show that superlattice alloys have a lower absorption coefficient at short wavelengths near the UV roll off.

An accepted technique for simulating pyrotechnic shock inputs has been the resonant plate test. The plate is designed so that its predominant modes generate the desired frequency content of a given shock test specification. The success of the test is dependent on the engineer's ability to effectively design and control the response of the resonant plate. In designing a test to simulated a pyrotechnic environment, the location and mass of the test item become very important considerations since they have a profound impact on the dynamic response of the resonant plate. A relatively massive test item can change the plates's resonant frequency. Differences in the relative frequencies of the test item's fixture and the resonant plate may also effect the input to the test items. In this study, a simple mock test assembly is used to study test item and resonant plate interactions during a test. The implications of this interaction regarding the deviations of the shock test specification are also discussed. Data from shock tests performed with the test assembly mounted to a rigid mounting surface and a flexible resonant plate are compared. Frequency response functions and shock response spectra are generated from the test data and compared to show the significance of: (1) the relative stiffness of the mounting surface; and (2) the location of the input control point during a resonant plate test. These factors are shown to be particularly important in using resonant plate testing to simulate pyrotechnic shock environments.