Office of Scientific and Technical Information
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy)Not a member yet
500 research outputs found
Sort by
Stratigraphy and Geologic Structure at the Chemical and Metallurgy (CMR) Building, Technical Area 3, Los Alamos National Laboratory
No full textNine shallow (c70 ft), closely spaced core holes were continuously cored in the upper units of the 1.22 Ma Tshirege Member of the Bandelier Tuff at Technical Area (TA)-3 of the Los Alamos National Laboratory. The goal of the investigation was to identify faults that may have potential for earthquake-induced surface rupture at the site of the Chemistry and Metallurgy Research (CMR) building, a sensitive Laboratory facility that houses nuclear materials research functions. The holes were located from 25 ft to 115 ft from the building perimeter. Careful mapping of Lithologic sequences in cores, supplemented with focused sampling for geochemical analyses, yielded high confidence in the accuracy of delineating buried contacts within the Tshirege Member. Geologic analysis and investigation of the trends of surfaces interpolated from contacts in the core holes using commercially available software helped infer minor faulting in the strata beneath the building. Results show that gently north-northeast-dipping beds underlie the CMR building. The tilted beds are faulted by two small, closely spaced, parallel reverse faults with a combined vertical separation of approximately 8 ft. The faults are inferred from lithologically and geochemically repeated sections of core at about 55-ft depth in hole SHB-CMR-6. The data from nearby core holes SHB-CMR-2 and SHB-CMR-3 permit the extension of the faults, albeit with decreasing separation, toward the southwest beneath the CMR building. The fault trend is consistent with mapped lineaments from aerial photography and with nearby mapped structure, but direct evidence of the faults' orientations is lacking. No other faults were detected beneath the CMR building by this drilling and analysis method, which can detect faults with greater than about 2 ft separation
Dynamic Fiber Optic Sensors Under Intense Radioactive Environments
No full textA liquid mercury target will be used as the neutron source for the proposed Spallation Neutron Source facility. This target is subjected to bombardment by short-pulse, high-energy proton beams. The intense thermal loads caused by interaction of the pulsed proton beam with the mercury create an enormous rate of temperature rise ({approximately}10{sup 7} K/s) during a very brief beam pulse ({approximately } 0.5 {micro}s). The resulting pressure waves in the mercury will interact with the walls of the mercury target and may lead to large stresses. To gain confidence in the mercury target design concept and to benchmark the computer design codes, we tested various electrical and optical sensors for measuring the transient strains on the walls of a mercury container and the pressures in the mercury. The sensors were attached on several sample mercury targets that were tested at various beam facilities: Oak Ridge Electron Linear Accelerator, Los Alamos Neutron Science Center-Weapons Neutron Research, and Brookhaven National Laboratory's Alternating Gradient Synchrotron. The effects of intense background radiation on measured signals for each sensor are described and discussed. Preliminary results of limited tests at these facilities indicate that the fiber optic sensors function well in this intense radiation environment, whereas conventional electrical sensors are dysfunctional
Task 6.3/6.7.4 - Engineering Performance of Advanced Structural Materials
No full textFuture energy systems will be required to fire low-grade fuels and meet higher energy conversion efficiencies than today's systems. The steam cycle used at present is-limited to a maximum temperature of 550C, because above that the stainless steel tubes deform and corrode excessively. However, to boost efficiency significantly, much higher working fluid temperatures are required. Although high-temperature alloys will suffice for the construction of these components in the near term, the greatest efficiency increases can only be reached with the use of advanced structural ceramic
Evaluation of Calendar Year 1997 Groundwater and Surface Water Quality Data For The Chestnut Ridge Hydrogeologic Regime At The U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee
No full textThis report presents an evaluation of the groundwater monitoring data obtained in the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime) during calendar year (CY) 1997. The Chestnut Ridge Regime encompasses a section of Chestnut Ridge bordered by the U.S. Department of Energy (DOE) Y-12 Plant in Bear Creek Valley (BCV) to the north, Scarboro Road to the eas~ Bethel Valley Road to the south, and an unnamed drainage basin southwest of the Y-12 Plant (Figure 1). Groundwater quality monitoring is performed at hazardous and nonhazardous waste management facilities in the regime under the auspices of the Y-12 Plant Groundwater Protection Program (GWPP). The CY 1997 monitoring data are presented in Calendar Year 1997 Annual Groundwater Monitoring Report for the Chestnut Ridge Hydrogeolo~"c Regime at the US. Department of Energy Y-12 Plant, Oak Ridge, Tennessee (MA Technical Services, Inc. 1998), which also presents results of site-specific monitoring data evaluations required under the Resource Conservation and Recovery Act (RCIL4) post-closure permit (PCP) for the Chestnut Ridge Regim
Evaluation Of Calendar Year 1997 Groundwater and surface Water Quality Data For the Bear Creek Hydrogeologic regime At The U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee
No full textThis report presents an evaluation of the groundwater and surface water monitoring data obtained in the Bear Creek Hydrogeologic Regime (Bear Creek Regime) during calendar year (CY) 1997. The monitoring data were obtained in compliance with the Resource Conservation and Recovery Act (RCRA) post-closure permit for the Bear Creek Regime and U.S. Department of Energy (DOE) Order 5400.1, and are reported ixx Calendar Year 1997 Annual Groundwater A40nitoringReport for the Bear Creek Hydrogeolo@"c Regime at the US. Department ofEnergy Y-12 Plant, Oak Ridge, Tennessee (AJA Technical Services, Inc. 1998a). This report provides an evaluation of the monitoring data with respect to historical results for each sampling location, the regime-wide extent of groundwater and surface water contamination, and long-term concentration trends for selected groundwater and surface water contaminants
FY1998 Annual Self-Evaluation Report for the Pacific Northwest National Laboratory
No full textNo abstract prepared
The DOE Knowledge Base Mthodology for the Creation of an Optimal Spatial Tessellation
No full textThe DOE Knowledge Base is a library of detailed information whose purpose is to improve the capability of the United States National Data Center (USNDC) to monitor compliance with the Comprehensive Test Ban Treaty (CTBT). Much of the data contained by the Knowledge Base is spatial in nature, and some of it is used to improve the accuracy with which seismic locations are determined while maintaining or improving current calculational perfor- mance. In this presentation, we define and describe the methodology used to create spatial tessellations of seismic data which are utilized with a gradient-modified natural-neighbor interpolation method to evaluate travel-time corrections. The goal is to interpolate a specified correction surface, or a group of them, with prescribed accuracy and surface smoothness requirements, while minimizing the number of data points necessary to represent the surface. Maintain- ing accuracy is crucial toward improving the precision of seismic origin location. Minimizing the number of nodes in the tessellation improves calculational and data access efficiency and performance. The process requires two initialization steps and an iterated 7 step algorithm for inserting new tessellation nodes. First, M residual data from ground truth events are included in the tessellation. These data remain fixed throughout the creation of the triangular tessellation. Next, a coarse grid of nodes is laid over the region to be tessellated. The coarse grid is necessary to define the boundary of the region to be tessellated. Next the 7 step iterated algorithm is performed to add new nodes to the tessellation to ensure that accuracy and smoothness requirements are met. These steps include 1) all data points in the tessellation are linked together to form a triangular tessellation using p standard Delaunay tessellation technique; 2) all of the data points, excluding the original data and boundruy nodes, are smoothed using a length-weighted Laplacian smoother to remove poorly formed triangles; 3) all new data points are assigned corrections by performing a Non-stationary Bayesian Kriging calculation for each new triangle node; 4) all nodes that exceed surface roughness requirements are split by inserting a new node at the mid-points of the edges that share the rough nod% 5) all remaining triangle edge midpoints and centers are inte~olated using gradient-modified natural-neighbor interpolation and kriged using the Bayesian IGiging algoritlm 6) new nodes are inserted into the tessellation at all edge and triangle mid-points that exceed the specified relative error tolerance between the interpo- lated and Iaiged values, and 7) all new insertion nodes are added to the tessellations node list. Steps 1 through 7 are repeated until all relative error and surface smoothness requirements are satisfied. Results indicate that node densities in the tessellation are largest in regions of high surface curvature as expected. Generally, gradient modified natural-neighbor interpolation methods do a better job than linear natural-neighbor methods at meeting accuracy requirements which translates to fewer nodes necessary to represent the surface
Development to Release of CTBT Knowledge Base Datasets
No full textFor the CTBT Knowledge Base to be useful as a tool for improving U.S. monitoring capabilities, the contents of the Knowledge Base must be subjected to a well-defined set of procedures to ensure integrity and relevance of the con- stituent datasets. This paper proposes a possible set of procedures for datasets that are delivered to Sandia National Laboratories (SNL) for inclusion in the Knowledge Base. The proposed procedures include defining preliminary acceptance criteria, performing verification and validation activities, and subjecting the datasets to approvrd by domain experts. Preliminary acceptance criteria include receipt of the data, its metadata, and a proposal for its usability for U.S. National Data Center operations. Verification activi- ties establish the correctness and completeness of the data, while validation activities establish the relevance of the data to its proposed use. Results from these activities are presented to domain experts, such as analysts and peers for final approval of the datasets for release to the Knowledge Base. Formats and functionality will vary across datasets, so the procedures proposed herein define an overall plan for establishing integrity and relevance of the dataset. Specific procedures for verification, validation, and approval will be defined for each dataset, or for each type of dataset, as appropriate. Potential dataset sources including Los Alamos National Laboratories and Lawrence Livermore National Laborato- ries have contributed significantly to the development of thk process
Area G Perimeter Surface-Soil and Single-Stage Water Sampling: Environmental Surveillance for Fiscal Years 1996 and 1997, Group ESH-19
No full textArea Gin Technical Area 54, has been the principal facility at Los Alamos National Laboratory for the storage and disposal of low-level, solid mixed, and transuranic radioactive waste since 1957. Soil samples were analyzed for tritium, isotopic plutonium, americium-241, and cesium-137. Thirteen metals-silver, arsenic, barium, beryllium, cadmium, chromium, mercury, nickel, lead, antimony, selenium, thallium and zinc-were analyzed on filtered-sediment fractions of the single-stage samples using standard analytical chemistry techniques. During the two years of sampling discussed in this report elevated levels of tritium (as high as 716,000 pCi/L) in soil were found for sampling sites adjacent to the tritium burial shafts located on the south- central perimeter of Area G. Additionally, tritium concentrations in soil as high as 38,300 pCi/L were detected adjacent to the TRU pads in the northeast comer of Area G. Plutonium-238 activities in FY96 soils ranged from 0.001-2.866 pCi/g, with an average concentration of 0.336& 0.734 pCdg. Pu-238 activities in FY97 soils ranged from 0.002-4.890 pCi/g, with an average concentration of 0.437 & 0.928 pCdg. Pu-239 activities in FY96 soils ranged from 0.009 to 1.62 pCdg, with an average of 0.177- 0.297 pCdg. Pu-239 activities in FY97 soils ranged from 0.005 to 1.71 pCi/g, with an average of 0.290- 0.415 pCi/g. The locations of elevated plutonium readings were consistent with the history of plutonium disposal at Area G. The two areas of elevated Am-241 activity reflected the elevated activities found for plutonium, the average values for Am-241 on soils were 0.6-2.07 pCi/g, and 0.10-0.14 pCi/g respectively for samples collected in FY96 and FY97. CS-137 activities in soils had average values of 0.33 pCi/g, and 0.28 pCi/g respectively for samples collected in FY96 and 97. There was no perimeter area where soil concentrations of CS-137 were significantly elevated
Data Rich, Information Poor
No full textSurviving in a data-rich environment means understanding the difference between data and information. This paper reviews an environmental case study that illustrates that understanding and shows its importance. In this study, a decision problem was stated in terms of au economic-objective fimction. The function contains a term that defines the stochastic relationship between the decision and the information obtained during field chamctetition for an environmental contaminant. Data is defied as samples drawn or experimental realizations of a mudom fimction. Information is defined as the quantitative change in the value of the objective fiction as a result of the sample