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A comparison of the shielding performances of the AT-400A, Model FL and Model AL-R8 containers

Description: A comparison of the neutron and photon dose rates at different locations on the outside surface of the Model AL-RB, Model FL and the AT-400A containers for a given pit load has been done in order to understand the shielding characteristics of these containers. The Model AL-R8 is not certified for transport and is only used for storage of pits, while the Model FL is a certified Type B pit transportation container. The AT-400A is being developed as a type B pit storage and transportation container. The W48, W56 and B83 pits were chosen for this study because of their encompassing features with regard to other pits presently being stored. A detailed description of the geometry and materials of these containers and of the neutron and photon emission spectra from the actinide materials present in the pit have been used in the calculations of the total dose rates. The calculations have been done using the three-dimensional, neutron-photon Monte Carlo code MCNP. The results indicate the need for a containment vessel (CV), as is found in the Model FL and AT-400A containers, in order to assure compliance with 10 CFR 71 regulations. The absence of a CV in the AL-R8 container results in total dose rates well above of the 200mr/hr allowed by the regulations for the W56 pit. Similar behavior will be expected for other pits with configuration similar to the W56 in which the main contribution to the dose rate is from the fission photons.
Date: April 28, 1995
Creator: Hansen, L.F.
Partner: UNT Libraries Government Documents Department

National Environmental Policy Act (NEPA) Compliance Guide, Sandia National Laboratories

Description: This report contains a comprehensive National Environmental Policy Act (NEPA) Compliance Guide for the Sandia National Laboratories. It is based on the Council on Environmental Quality (CEQ) NEPA regulations in 40 CFR Parts 1500 through 1508; the US Department of Energy (DOE) N-EPA implementing procedures in 10 CFR Part 102 1; DOE Order 5440.1E; the DOE ``Secretarial Policy Statement on the National Environmental Policy Act`` of June 1994- Sandia NEPA compliance procedures-, and other CEQ and DOE guidance. The Guide includes step-by-step procedures for preparation of Environmental Checklists/Action Descriptions Memoranda (ECL/ADMs), Environmental Assessments (EAs), and Environmental Impact Statements (EISs). It also includes sections on ``Dealing With NEPA Documentation Problems`` and ``Special N-EPA Compliance Issues.``
Date: August 1, 1995
Creator: Hansen, R.P.
Partner: UNT Libraries Government Documents Department

{sup 3}He[pol]({rvec e}, e{prime})X and the neutron electromagnetic form factors

Description: Recent data for the spin-dependent A{sub T}, and A{sub TL}, asymmetries in {sup 3}He[pol]({rvec e}, e{prime}) quasielastic scattering are reviewed. The neutron electric and magnetic form factors are extracted from the data using a plane wave impulse approximation (PWIA) model, and the model uncertainties are estimated. The extracted G{sub M}{sup n} is in agreement with the dipole prediction as well as with other recent experiments. No meaningful result for G{sub E}{sup n} is obtained due to large uncertainties and possible final-state interaction effects. At higher Q{sup 2}, the determination of G{sub E}{sup n} in {sup 3}He[pol]({rvec e},e{prime}) does appear feasible based on the plane wave impulse approximation (PWIA) predictions.
Date: December 31, 1995
Creator: Hansen, J.O.
Partner: UNT Libraries Government Documents Department

Computer imaging of EBR-II fuel handling equipment

Description: This paper describes a three-dimensional graphics application used to visualize the positions of remotely operated fuel handling equipment in the EBR-II reactor. A three-dimensional (3D) visualization technique is necessary to simulate direct visual observation of the transfers of fuel and experiments into and out of the reactor because the fuel handling equipment is submerged in liquid sodium and therefore is not visible to the operator. The system described in this paper uses actual signals to drive a three-dimensional computer-generated model in real-time in response to movements of equipment in the plant This paper will present details on how the 3D model of the intank equipment was created and how real-time dynamic behavior was added to each of the moving components.
Date: June 1, 1995
Creator: Peters, G.G. & Hansen, L.H.
Partner: UNT Libraries Government Documents Department

Parallel rendering techniques for massively parallel visualization

Description: As the resolution of simulation models increases, scientific visualization algorithms which take advantage of the large memory. and parallelism of Massively Parallel Processors (MPPs) are becoming increasingly important. For large applications rendering on the MPP tends to be preferable to rendering on a graphics workstation due to the MPP`s abundant resources: memory, disk, and numerous processors. The challenge becomes developing algorithms that can exploit these resources while minimizing overhead, typically communication costs. This paper will describe recent efforts in parallel rendering for polygonal primitives as well as parallel volumetric techniques. This paper presents rendering algorithms, developed for massively parallel processors (MPPs), for polygonal, spheres, and volumetric data. The polygon algorithm uses a data parallel approach whereas the sphere and volume render use a MIMD approach. Implementations for these algorithms are presented for the Thinking Ma.chines Corporation CM-5 MPP.
Date: July 1, 1995
Creator: Hansen, C.; Krogh, M. & Painter, J.
Partner: UNT Libraries Government Documents Department

Long term decontamination at the Hanford Site: A case study

Description: This paper describes an engineering study that evaluates decontamination requirements at Hanford and the potential reutilization of the first plutonium processing production facility as a decontamination facility. The logic used to develop the study, the options available for a long-term decontamination mission, and the resultant strategy recommended in the study are presented. The paper provides a starting point for other similar study efforts. The process flowsheets, regulatory restrictions, and preconceptual designs developed in this study are common throughout the nuclear waste industry.
Date: February 1, 1995
Creator: Geuther, W.J. & Hansen, G.E.
Partner: UNT Libraries Government Documents Department

Technical evaluation of a USSC Integrated/Direct Mount PV Roofing Module system at NREL

Description: The results of a 16 month technical evaluation performed on a nominal 1 kW{sub ac} utility-interconnect amorphous silicon PV system deployed at the National Renewable Energy Laboratory`s PV outdoor test site are given here. The system employs 64 prototype United Solar Systems Corp. Integrated/Direct Mount PV Roofing Modules mounted on simulated attic/roof structures. In this paper we show that the PV array fill factor has been relatively stable with respect to time and that the seasonal variations in performance can be largely attributed to seasonal variations in current. We also show that in determining the summer and winter ac power output, the summation of the manufacturer-supplied module peak powers at STC for a similarly located and configured a-Si PV array should be derated by factors of approximately of 0.83 and 0.78 for summer and winter operation, respectively.
Date: May 1, 1995
Creator: Strand, T.; Hansen, R. & Mrig, L.
Partner: UNT Libraries Government Documents Department

Cost-effective data-parallel load balancing

Description: Load balancing algorithms improve a program`s performance on unbalanced datasets, but can degrade performance on balanced datasets, because unnecessary load redistributions occur. This paper presents a cost-effective data-parallel load balancing algorithm which performs load redistributions only when the possible savings outweigh the redistribution costs. Experiments with a data-parallel polygon renderer show a performance improvement of up to a factor of 33 on unbalanced datasets and a maximum performance loss of only 27 percent on balanced datasets when using this algorithm.
Date: May 1, 1995
Creator: Hansen, C.D. & Ahrens, J.P.
Partner: UNT Libraries Government Documents Department

Large-scale dynamic compaction demonstration using WIPP salt: Fielding and preliminary results

Description: Reconsolidation of crushed rock salt is a phenomenon of great interest to programs studying isolation of hazardous materials in natural salt geologic settings. Of particular interest is the potential for disaggregated salt to be restored to nearly an impermeable state. For example, reconsolidated crushed salt is proposed as a major shaft seal component for the Waste Isolation Pilot Plant (WIPP) Project. The concept for a permanent shaft seal component of the WIPP repository is to densely compact crushed salt in the four shafts; an effective seal will then be developed as the surrounding salt creeps into the shafts, further consolidating the crushed salt. Fundamental information on placement density and permeability is required to ensure attainment of the design function. The work reported here is the first large-scale compaction demonstration to provide information on initial salt properties applicable to design, construction, and performance expectations. The shaft seals must function for 10,000 years. Over this period a crushed salt mass will become less permeable as it is compressed by creep closure of salt surrounding the shaft. These facts preclude the possibility of conducting a full-scale, real-time field test. Because permanent seals taking advantage of salt reconsolidation have never been constructed, performance measurements have not been made on an appropriately large scale. An understanding of potential construction methods, achievable initial density and permeability, and performance of reconsolidated salt over time is required for seal design and performance assessment. This report discusses fielding and operations of a nearly full-scale dynamic compaction of mine-run WIPP salt, and presents preliminary density and in situ (in place) gas permeability results.
Date: October 1, 1995
Creator: Ahrens, E.H. & Hansen, F.D.
Partner: UNT Libraries Government Documents Department

Parallel sphere rendering

Description: Sphere rendering is an important method for visualizing molecular dynamics data. This paper presents a parallel divide-and-conquer algorithm that is almost 90 times faster than current graphics workstations. To render extremely large data sets and large images, the algorithm uses the MIMD features of the supercomputers to divide up the data, render independent partial images, and then finally composite the multiple partial images using an optimal method. The algorithm and performance results are presented for the CM-5 and the T3D.
Date: May 1, 1995
Creator: Krogh, M.; Hansen, C.; Painter, J. & de Verdiere, G.C.
Partner: UNT Libraries Government Documents Department

Polycrystalline thin-film module and system performance

Description: The Module and System Performance and Engineering Project at the National Renewable Energy Laboratory (NREL) conducts in-situ technical evaluations of photovoltaic (PV) modules and systems (arrays). These evaluations on module/array performance and stability are conducted at the NREL Photovoltaic Outdoor Test Facility (OTF) in Golden, CO. The modules and arrays are located at 39.7{degree}N latitude, 105.2{degree}W longitude, and at 1,782 meters elevation. Currently, two polycrystalline thin-film technologies are the focus of the research presented here. The module structures are copper indium diselenide (CIS) from Siemens Solar Industries and cadmium telluride (CdTe) from Solar Cells, Inc. The research team is attempting to correlate individual module performance with array performance for these two polycrystalline thin-film technologies. This is done by looking at module and array performance over time. Also, temperature coefficients are determined at both the module and array level. Results are discussed.
Date: November 1, 1995
Creator: Strand, T.; Kroposki, B.; Hansen, R. & Mrig, L.
Partner: UNT Libraries Government Documents Department

Variability in properties of Salado Mass Concrete

Description: Salado Mass Concrete (SMC) has been developed for use as a seal component in the Waste Isolation Pilot Plant. This concrete is intended to be mixed from pre-bagged materials, have an initial slump of 10 in., and remain pumpable and placeable for two hours after mixing. It is a mass concrete because it will be placed in monoliths large enough that the heat generated during cement hydration has the potential to cause thermal expansion and subsequent cracking, a phenomenon to avoid in the seal system. This report describes effects on concrete properties of changes in ratio of water to cement, batch size, and variations in characteristics of different lots of individual components of the concrete. The research demonstrates that the concrete can be prepared from laboratory-batched or pre-bagged dry materials in batches from 1.5 ft{sup 3} to 5.0 yd{sup 3}, with no chemical admixtures other than the sodium chloride added to improve bonding with the host rock, at a water-to-cement ratio ranging from 0.36 to 0.42. All batches prepared according to established procedures had adequate workability for at least 1.5 hours, and achieved or exceeded the target compressive strength of 4500 psi at 180 days after casting. Portland cement and fly ash from different lots or sources did not have a measurable effect on concrete properties, but variations in a shrinkage-compensating cement used as a component of the concrete did appear to affect workability. A low initial temperature and the water-reducing and set-retarding functions of the salt are critical to meeting target properties.
Date: August 1, 1995
Creator: Wakeley, L. D.; Harrington, P. T. & Hansen, F. D.
Partner: UNT Libraries Government Documents Department

Case studies of sealing methods and materials used in the salt and potash mining industries

Description: Sealing methods and materials currently used in salt and potash industries were surveyed to determine if systems analogous to the shaft seal design proposed for the Waste Isolation Pilot Plant (WIPP) exist. Emphasis was first given to concrete and then expanded to include other materials. Representative case studies could provide useful design, construction, and performance information for development of the WIPP shaft seal system design. This report contains a summary of engineering and construction details of various sealing methods used by mining industries for bulkheads and shaft liners. Industrial experience, as determined from site visits and literature reviews, provides few examples of bulkheads built in salt and potash mines for control of water. Sealing experiences representing site-specific conditions often have little engineering design to back up the methods employed and even less quantitative evaluation of seal performance. Cases examined include successes and failures, and both contribute to a database of experiences. Mass salt-saturated concrete placement under ground was accomplished under several varied conditions. Information derived from this database has been used to assess the performance of concrete as a seal material. Concrete appears to be a robust material with successes in several case studies. 42 refs.
Date: November 1995
Creator: Eyermann, T. J.; van Sambeek, L. L. & Hansen, F. D.
Partner: UNT Libraries Government Documents Department

The ACL Message Passing Library

Description: This paper presents the ACL (Advanced Computing Lab) Message Passing Library. It is a high throughput, low latency communications library, based on Thinking Machines Corp.`s CMMD, upon which message passing applications can be built. The library has been implemented on the Cray T3D, Thinking Machines CM-5, SGI workstations, and on top of PVM.
Date: September 1, 1995
Creator: Painter, J.; McCormick, P.; Krogh, M.; Hansen, C. & Colin de Verdiere, G.
Partner: UNT Libraries Government Documents Department

ACLMPL: Portable and efficient message passing for MPPs

Description: This paper presents the Advanced Computing Lab Message Passing Library (ACLMPL). Modeled after Thinking Machines Corporation`s CMMD, ACLMPL is a high throughout, low latency communications library for building message passing applications. The library has been implemented on the Cray T3D, Thinking Machines CM-5, SGI workstations, and on top of PVM. On the Cray T3D, benchmarks show ACLMPL to be 4 to 7 times faster than MPI or PVM.
Date: September 19, 1995
Creator: Painter, J.; Krogh, M.; Hansen, C.; McCormick, P. & de Verdiere, G.C.
Partner: UNT Libraries Government Documents Department

Investigation of Newton-Krylov algorithms for low Mach number compressible flow

Description: Fully coupled Newton-Krylov algorithms are used to solve steady speed compressible flow past a backward facing step flow Mach and Reynolds numbers. Various preconditioned Krylov iterative methods are used to solve the linear systems that arise on each Newton step, specifically Lanczos-based and Arnoldi-based algorithms. Several preconditioning strategies are considered to improve the performance of these iterative techniques, including incomplete lower-upper factorization with various levels of fill-in [ILU(k)] and domain based additive and multiplicative Schwarz type preconditioning both with and without overlapping domains. The ILU(K) preconditioners were generally less reliable for lower values of the flow Mach number, and exhibited strong sensitivity to cell ordering. In addition, the parallel nature of the domain based preconditioners is exploited on both a shared memory computer and a distributed system of workstations. Important aspects of the numerical solutions are discussed.
Date: October 1, 1995
Creator: McHugh, P.R.; Knoll, D.A.; Mousseau, V.A. & Hansen, G.A.
Partner: UNT Libraries Government Documents Department

Photon burst mass spectrometry--ultrasensitive detection of rare isotopes

Description: Progress is reported on the development of a new technique for measurement of trace levels of radioisotopes which is based on fluorescence detection of output from a mass spectrometer. Significant achievements include the observation of fluorescence and burst signals from Kr isotopes, including enriched samples of {sup 85}Kr with a 4-collector system. An abundance sensitivity is demonstrated with {sup 83}Kr and {sup 85}Kr.
Date: February 1, 1995
Creator: Hansen, C.S.; Pan, X.J.; Fairbank, W.M. Jr.; Oona, H.; Chamberlin, E.P.; Nogar, N.S. et al.
Partner: UNT Libraries Government Documents Department

TWRS tank waste pretreatment process development hot test siting report

Description: This report is the sixth in a series that have assessed the hot testing requirements for TWRS pretreatment process development and identified the hot testing support requirements. This report, based on the previous work, identifies specific hot test work packages, matches those packages to specific hot cell facilities, and provides recommendations of specific facilities to be employed for the pretreatment hot test work. Also identified are serious limitations in the tank waste sample retrieval and handling infrastructure. Recommendations are provided for staged development of 500 mL, 3 L, 25 L and 4000 L sample recovery systems and specific actions to provide those capabilities.
Date: February 1, 1995
Creator: Howden, G.F.; Banning, D.L.; Dodd, D.A.; Smith, D.A.; Stevens, P.F.; Hansen, R.I. et al.
Partner: UNT Libraries Government Documents Department

Evaluation of potential crushed-salt constitutive models

Description: Constitutive models describing the deformation of crushed salt are presented in this report. Ten constitutive models with potential to describe the phenomenological and micromechanical processes for crushed salt were selected from a literature search. Three of these ten constitutive models, termed Sjaardema-Krieg, Zeuch, and Spiers models, were adopted as candidate constitutive models. The candidate constitutive models were generalized in a consistent manner to three-dimensional states of stress and modified to include the effects of temperature, grain size, and moisture content. A database including hydrostatic consolidation and shear consolidation tests conducted on Waste Isolation Pilot Plant and southeastern New Mexico salt was used to determine material parameters for the candidate constitutive models. Nonlinear least-squares model fitting to data from the hydrostatic consolidation tests, the shear consolidation tests, and a combination of the shear and hydrostatic tests produces three sets of material parameter values for the candidate models. The change in material parameter values from test group to test group indicates the empirical nature of the models. To evaluate the predictive capability of the candidate models, each parameter value set was used to predict each of the tests in the database. Based on the fitting statistics and the ability of the models to predict the test data, the Spiers model appeared to perform slightly better than the other two candidate models. The work reported here is a first-of-its kind evaluation of constitutive models for reconsolidation of crushed salt. Questions remain to be answered. Deficiencies in models and databases are identified and recommendations for future work are made. 85 refs.
Date: December 1, 1995
Creator: Callahan, G.D.; Loken, M.C.; Sambeek, L.L. Van; Chen, R.; Pfeifle, T.W.; Nieland, J.D. et al.
Partner: UNT Libraries Government Documents Department