The physical mechanisms that contribute to harmonic radiation in free-electron laser systems are examined. Mathematical models for the spontaneous and coherent-spontaneous emission in plane-polarized wigglers are given. How these models are used to perform numerical simulations is discussed. Modifications of the models to incorporate non-ideal free-electron laser effects are reviewed. 19 refs., 4 figs.

Tests of austenitic stainless steel clad U-xP-10Zr fuel (x=o, 8, 19 wt. %) to peak burnups as high as 18.4 at. % have been completed in the EBR-II. Fuel swelling and fractional fission gas release are slowly increasing functions of burnup beyond 2 at. % burnup. Increasing plutonium content in the fuel reduces swelling and decreases the amount of fission gas which diffuses from fuel to plenum. LIFE-METAL code modelling of cladding strains is consistent with creep by fission gas loading and irradiation-induced swelling mechanisms. Fuel/cladding chemical interaction involves the ingress of rare-earth fission products. Constituent redistribution in the fuel had not limited steady-state performance. Cladding breach behavior at closure welds, in the gas plenum, and in the fuel column region have been benign events. 3 refs., 5 figs.

The Fast Flux Facility (FFTF) is a demonstration and test facility of the sodium-cooled fast breeder reactor. A power addition'' to the facility is being considered to convert some of the dumped, unused heat into electricity generation. Components and piping systems to be added are sodium-water steam generators, sodium loop extensions from existing dump heat exchangers to sodium-water steam generators, and conventional water/steam loops. The sodium loops can be subjected to the dynamic loadings of pressure pulses that are caused by postulated sodium leaks and subsequent sodium-water reaction in the steam generator. The existing FFTF secondary pipes and the new power addition sodium loops were evaluated for exposure to the dynamic effect of the sodium-water reaction. Elastic and simplified inelastic dynamic analyses were used in this feasibility study. The results indicate that both the maximum strain and strain range are within the allowable limits. Several cycles of the sodium-water reaction can be sustained by the sodium pipes that are supported by ordinary pipe supports and seismic restraints. Expensive axial pipe restraints to withstand the sodium-water reaction loads are not needed, because the pressure-pulse-induced alternating bending stresses act as secondary stresses and the pressure pulse dynamic effect is a deformation-controlled quantity …

A geothermal gradient core hole (TCB-1) was drilled to a depth of 700+ m at the Tecuamburro geothermal site, Guatemala during February and March, 1990. The core hole is located low on the northern flank of the Tecuamburro Volcano complex. Preliminary analysis of cores (>98% core recovery) indicates that the hydrothermal system may be centered in the 4-km-diameter Chupadero Crater, which has been proposed as the source of pyroxene pumice deposits in the Tecuamburro area. TCB-1 is located 300 m south of a 300-m-diameter phreatic crater, Laguna Ixpaco; the core hole penetrates the thin edge of a tuff ring surrounding Ixpaco and zones of hydrothermal brecciation within the upper 150 m may be related to the phreatic blast, dated at 2,910 {sup 14}C years. At the time of this writing, the unequilibrated temperature at a depth of 570m was 180{degree}C. Data on fracturing, permeability, hydrothermal alteration, and temperature will be presented. 3 refs., 3 figs.

We drive the five point form of the nodal diffusion equations in two-dimensional Cartesian geometry and develop three iterative schemes to solve the discrete-variable equations: the unaccelerated, partial Successive Over Relaxation (SOR), and the full SOR methods. By decomposing the iteration error into its Fourier modes, we determine the spectral radius of each method for infinite medium, uniform model problems, and for the unaccelerated and partial SOR methods for finite medium, uniform model problems. Also for the two variants of the SOR method we determine the optimal relaxation factor that results in the smallest number of iterations required for convergence. Our results indicate that the number of iterations for the unaccelerated and partial SOR methods is second order in the number of nodes per dimension, while, for the full SOR this behavior is first order, resulting in much faster convergence for very large problems. We successfully verify the results of the spectral analysis against those of numerical experiments, and we show that for the full SOR method the linear dependence of the number of iterations on the number of nodes per dimension is relatively insensitive to the value of the relaxation parameter, and that it remains linear even for heterogenous …

An iron-titanium film 300 nm thick was deposited on a tool steel (1.55% C, 0.3% Si, 0.3% Mn, 12% Cr, 0.8% Mo, and 0.8% V) by coevaporation of Fe and Ti. Subsequently this surface film was implanted with carbon at energies of 55, 120, and 200 keV to a total fluence of 1.24 {times} 10{sup 18} C{sup +}/cm{sup 2}. This treatment produced a surface hardness of 15 GPa. The effect of this coating on unlubricated wear and friction was tested in air at a relative humidity of 10% in a pin-on-disc tester using a 440C pin as a counterface. The sliding mechanism of the untreated substrate was found to be based on the transfer of pin material and subsequent growth of uneven oxide hillocks on the wear track. Oxide scales were observed also on a wear scar of the pin, presumably as a result of back-deposition. In contrast, the sliding mechanism on the coated sample was drastically different. A more uniform transfer film originating in the coating was found on the pin, resulting in sliding between identical materials. No wearthrough of the coating occurred during the test of 5000 cycles at a Hertzian pressure of 835 MPa, and the surface …

This paper describes the development and implementation of a digital model-based reactivity control system that incorporates a knowledge of the plant physics into the control algorithm to improve system performance. This controller is composed of a model-based module and modified proportional-integral-derivative (PID) module. The model-based module has an estimation component to synthesize unmeasurable process variables that are necessary for the control action computation. These estimated variables, besides being used within the control algorithm, will be used for diagnostic purposes by a supervisory control system under development. The PID module compensates for inaccuracies in model coefficients by supplementing the model-based output with a correction term that eliminates any demand tracking or steady state errors. This control algorithm has been applied to develop controllers for a simulation of liquid metal reactors in a multimodular plant. It has shown its capability to track demands in neutron power much more accurately than conventional controllers, reducing overshoots to almost negligible value while providing a good degree of robustness to unmodeled dynamics. 10 refs., 4 figs.

The Light-Weight Radioisotope Heater Unit (LWRHU) will be used on the NASA Galileo Mission to provide thermal energy to the various systems on the orbiter and probe that are adversely affected by the low temperature a spacecraft encounters during a long interplanetary mission. Using these plutonia-fueled sources in 1-W increments permits employment of a single design and provides the spacecraft user the option of how many to use and where to position them to satisfy the proper thermal environment for components requiring such consideration. The use of the radioisotope {sup 238}Pu in these devices necessitates the assessment of postulated radiological risks which might be experienced in case of accidents or malfunctions of the space shuttle or the spacecraft during phases of the mission in the vicinity of the earth. Included are data for the design, mission descriptions, postulated accidents with their consequences, test data, and the derived source terms and personnel exposures for the various events. 4 refs., 4 figs., 1 tab.

One purpose of this study is to estimate the relationship in commercial buildings between conservation investments, fuel prices, building occupancy and building characteristics for new buildings and for existing buildings. The database is a nationwide survey of energy in commercial buildings conducted by the Energy Information Administration (EIA) in 1906. Some simple cross-tabulations indicate that conservation measures vary with building size, building age, and fuel used for building heating. Regression estimates of a conservation model indicate that the number of conservation model indicate that the number of conservation features installed during construction is a positive function of the price of the heating fuel at the time of construction. Subsequent additions of conservation features are positively correlated with increases in heating fuel prices. Given the EIA projection of relatively stable future energy prices, the number of retrofits may not increase significantly. Also, energy efficiency in new buildings may not continue to increase relative to current new buildings. If fuel prices affect consumption via initial conservation investments, current fuel prices, marginal or average, are not the appropriate specification. The fuel price regression results indicate that conservation investments in new buildings are responsive to market signals. Retrofits are less responsive to market signals. …

Over the past 25 years extensive federal legislation involving the handling and transport of hazardous materials/waste has been passed that has resulted in numerous overlapping regulations administered and enforced by different federal agencies. The handling and transport of hazardous materials/waste involves a significant number of workers who are subject to a varying degree of risk should an accident occur during handling or transport. Effective transportation training can help workers address these risks and mitigate them, and at the same time enable ORNL to comply with the federal regulations concerning the transport of hazardous materials/waste. This presentation will outline how the Environmental and Health Protection Division's Technical Resources and Training Section at the Oak Ridge National Laboratory, working with transportation and waste disposal personnel, have developed and implemented a comprehensive transportation safety training program to meet the needs of our workers while satisfying appropriate federal regulations. 8 refs., 3 tabs.

The Scalable Coherent Interface (IEEE P1596) is establishing an interface standard for very high performance multiprocessors, supporting a cache-coherent-memory model scalable to systems with up to 64K nodes. This Scalable Coherent Interface (SCI) will supply a peak bandwidth per node of 1 GigaByte/second. The SCI standard should facilitate assembly of processor, memory, I/O and bus bridge cards from multiple vendors into massively parallel systems with throughput far above what is possible today. The SCI standard encompasses two levels of interface, a physical level and a logical level. The physical level specifies electrical, mechanical and thermal characteristics of connectors and cards that meet the standard. The logical level describes the address space, data transfer protocols, cache coherence mechanisms, synchronization primitives and error recovery. In this paper we address logical level issues such as packet formats, packet transmission, transaction handshake, flow control, and cache coherence. 11 refs., 10 figs.

This paper presents the results of a research project in which tractor manufacturers and carrier companies were interviewed to gather information on operational concerns in specifying a tractor to haul legal weight spent fuel casks. The system was assumed to operate very close to the 80,000 pound legal weight limit. Safety, performance, reliability, and maintainability of equipment were factors given particular attention. The interaction between driver fatigue, safety, and equipment was also discussed. Innovative operating strategies that could save weight were discussed. The paper concluded that operational considerations require that planners working with standard off-the-shelf tractor equipment should allow at least 17,350 pounds for the weight of the tractor as a starting point from which further weight reduction analysis can proceed. 4 refs., 3 figs.

Two types of neural network beauty trigger architectures, based on identification of electrons in jets and recognition of secondary vertices, have been simulated in the environment of the Fermilab CDF experiment. The efficiencies for B's and rejection of background obtained are encouraging. If hardware tests are successful, the electron identification architecture will be tested in the 1991 run of CDF. 10 refs., 5 figs., 1 tab.

The ternary alloy, Ti - 49 at% Al -2 at. % W, was produced using Rotating Electrode Powder (REP) compacted by hot extrusion. The tensile properties of this alloy (strength, ductility and fracture mode) were studied from room temperature to 900{degrees}C. Constant load creep properties were measured from 700 to 900{degrees}C and analyzed using conventional power law equations to calculate the stress exponent and activation energy. These parameters were approximately 4 and 400 KJ/mole respectively. TEM examination showed that the W was held in solid solution during the tensile and creep deformation when the material was tested in the as-extruded' condition. These results are interpreted as evidence for solid solution strengthening of the TiAl matrix by the W solute. 13 refs., 3 figs., 4 tabs.

The isotopes {sup 249}Cf and {sup 249}Bk are chemically separated by ion exchange chromatography at the Oak Ridge National Laboratory Transuranium Processing Plant. Control of the separation depends on the operator's ability to distinguish electronically between alpha radiation from the {sup 249}Cf and beta particles from the {sup 249}Bk. This new monitoring system consists of two surface-barrier detectors, each having its own channel of electronics and data acquisition. The two detectors are mounted in a Teflon holder and positioned near the tip of the ion exchange column, where droplets of solution are formed as the nuclides are eluted from the column. Amplifier gain and window settings on the single-channel analyzer (SCA) for one detector are adjusted to count the energetic alpha particles from the {sup 249}Cf, while the electronic settings of the other channel are adjusted to count the lower energy beta particles from {sup 249}Bk. The alpha count rate will increase first as {sup 249}Cf passes from the column; then the beta count rate increases, indicating that {sup 249}Bk is being eluted. At this point, the operator can make a cut in the separation process. 4 figs.

This study investigates the current spent nuclear fuel cask fleet capability in the United States. In addition, it assesses the degree to which the current fleet would be available, as a contingency, until proposed Office of Civilian Radioactive Waste Management casks become operational. A limited fleet of ten spent fuel transportation casks is found to be readily available for use in Federal waste management efforts over the next decade.

This report contains abstracts on the following topics: techniques of scanning probe microscopy; new types of radiation; a search for wake-riding electrons using slow antiproton beams; antiproton wake: theory; bending of swift ion beams by graphite foils; angular momentum distribution of autoionizing rydberg states: produced by 64 MeV S ions in collisions with C foils; multiphonon energy exchange in atom-surface collisions; plans for positron experiments; resonant coherent excitation: experiment; line shapes in resonant coherent excitation: theory; MUSE experiments and Monte Carlo simulation; inelastic interactions of electrons and positrons with solids; density fluctuation detection; cluster-impact fusion; a model for cluster-impact fusion; thoughts on cold fusion; and plasmon decay.

Pressurized-water reactors have reactor physics and fuel management characteristics which are very amenable to simplified analysis. Given models which account for the dominant features of core and fuel performance, it is possible to rapidly perform relatively accurate scoping studies of many years of reactor operation in just a few hours on a modern (386-class) microcomputer. Models are described for burnup-dependent cross-section generation, for burnup of fuel under irradiation, and for computation of radial power distributions in hexagonal geometry assuming hexagonal fuel assemblies. Comparisons with more elaborate methods are given in order to validate the models, and to quantify the accuracy of the results. 16 refs., 5 figs., 5 tabs.

A number of recent experiments have pointed out the need of including the effects of aperture variation within each fracture in predicting flow and transport properties of fractured media. This paper introduces a new approach in which medium properties, such as the permeability to flow and dispersivity in tracer transport, are correlated to only three statistical parameters describing the fracture aperture probability distribution and the aperture spatial correlation. We demonstrate how saturated permeability and relative permeabilities for flow, as well as dispersion for solute transport in fractures may be calculated. We are in the process of examining the applicability of these concepts to field problems. Results from the evaluation and analysis of the recent Stripa-3D field data are presented. 13 refs., 10 figs.

The first physics measurements of a heterogeneous core on the critical assembly ZPPR-7 at ANL showed that the C/E ratios with ENDF/B data for the worths of the control rods in the outer bank were several percent higher than those at the inner bank positions. This radial variation in the C/E for the rod worths was further confirmed in the analysis of the large conventional core ZPPR-10, and again in the analysis of the large heterogeneous core series ZPPR-13. In the design of a power reactor, the number of control rods, and their disposition, are determined by calculations. Misprediction of the worth of the control rods can lead to serious economic penalties by restricting the operation of the core. Retrofitting a core to accommodate more worth will be costly and is likely to lead to a non-optimized core. This document provides a discussion of these calculations. 7 refs., 7 figs., 12 tabs.

In-situ experiments to determine the hydrologic and mechanical characteristics of large naturally occurring fractures have been conducted at the NAGRA test site in Grimsel, Switzerland. In addition to seismic measurements across a fracture resulting from pressurization of the zone was also measured. The deformation is modeled in three different ways: as a mathematical crack employing linear elastic fracture mechanics; as a mathematical crack with an additional restraining stiffness between the faces of the crack, and as a row of coplanar two-dimensional cracks. 6 refs., 6 figs.

The E731 experiment at Fermilab has measured the CP violation parameter Re({var epsilon}{prime}/{var epsilon}) in K{sub L,S}{yields}{pi}{pi} decay. Four decay modes were collected simultaneously to reduce systematic errors. The result is Re({var epsilon}{prime}/{var epsilon})={minus}0.0005 {plus minus} 0.0014 (stat.) {plus minus} 0.0006 (syst.), and gives no evidence for direct CP violation. 7 refs., 3 figs., 1 tab.

Time-of-flight (TOF) neutron diffraction as performed at a spallation neutron source such as LANSCE offers special features that makes it potentially useful for the determination of the texture (preferred orientation, particle size and strain) of polycrystalline materials. 4 refs., 6 figs.

The charge of this group was to evaluate the physics that can be done with a high luminosity {mu} scattering experiment at FNAL using the upgraded Tevatron muon beam, and consider the apparatus required. In this report, the physics that can be accomplished with a high luminosity {mu} scattering experiment is evaluated. The CERN and FNAL {mu} beams are compared in the context of such an experiment. The expected muon flux with the upgraded machine is estimated. Two possible detectors are compared: the air-core toroid experiment proposed by Guyot et al., and an upgraded version of the E665 double-diode apparatus now in place at FNAL. The relative costs of the detectors are considered. A list of detailed questions that need to be answered regarding the double-diode experiment has be compiled. 2 refs., 10 figs., 2 tabs.