Electron microprobe analysis shows that iron, manganese, and nickel are inhomogeneously distributed in hot-cross-rolled plate and high-energy-rate forgings of 21Cr-6Ni-9Mn steel but that chromium is homogeneously distributed. Increases in iron content correlate with decreases in manganese and nickel. Rolling and forging flow lines occur in regions with high iron and low manganese and nickel. High-energy-rate forging increases inhomogeneity. Inhomogeneities are suspected to exist in the original ingot, where they are given directionality by rolling and are enhanced by high-energy-rate forging. This report discusses this study.

Previous research in this laboratory led to the conclusion that the low temperature intergranular fracture mode in Fe-Mn alloys is microstructurally determined, and does not require metalloid segregation or other chemical contamination. That conclusion was tested in the present investigation, which used high resolution scanning Auger microscopy to study the intergranular fracture surfaces. The fracture mode at liquid nitrogen temperature was found to be intergranular fracture whenever the alloy was quenched from the austenite field, irrespective of the austenization time or temperature. High resolution chemical analyses of the intergranular fracture surfaces failed to reveal any consistent segregation of P, S, 0, or N. The occasional appearance of sulfur or oxygen on the fracture surface was found to be due to a low density precipitation of MnS and MnO{sub 2} along the prior austenite grain boundaries. Excepting these dispersed precipitates, there was no evidence of manganese enrichment of the prior austenite grain boundaries. A slight segregation of carbon was found along the grain boundaries, but does not appear to be implicated in the tendency toward intergranular fracture. The present results hence reinforce the conclusion that the low temperature intergranular fracture of Fe-12Mn is microstructurally determined.

Categorization supports decision making, letting an analyst look at data from different perspectives and different levels of detail. An approach to data analysis is described in which membership in subjectively defined categories is modeled by the fuzzy nature of color categories and presented via computer graphics for visual inspection by the analyst.

A beam of D{sup -} ions has been produced at 7-13 keV, with currents up to 2.2 {angstrom}, using charge exchange in sodium vapor. The beam profile is bi-Gaussian with angular divergence 0.7{sup o} x 2.8{sup o} and peak current density 15 mA/cm{sup 2}. The characteristics of the beam are in excellent agreement with predictions based on atomic cross sections. The sodium vapor target is formed by a jet directed across the beam. The sodium density drops rapidly in the beamline downstream from the charge exchange region, decreasing three orders of magnitude in 15 cm. Measurement and analysis of the plasma accompanying the beam demonstrate that plasma densities nearly equal to the beam density are obtained 1 m from the charge exchange medium. The plasma produced in the sodium is thus well confined to the charge exchange region and does not propagate along the beam.

The nuclear fluid dynamical model with final thermal breakup is used to study the reactions {sup 20}Ne + {sup 238}U and {sup 40}Ar + {sup 40}Ca at E{sub LAB} = 390 MeV/n. The calculated double differential cross sections d{sup 2}{sigma}/d{Omega}dE are in agreement with recent experimental data. However, it is shown that the azimuthal dependence of the triple differential distributions d{sup 3}{sigma}/dEdcos{theta}d{phi}, to be obtained from 4{pi} exclusive experiments with single event analysis, can yield considerably deeper insight into the collision process and allow for snapshots of the reactions. Strongly correlated jets of nuclear matter are predicted.

The adsorption of a variety of molecules on Ni(111) is studied UV/visible spectroscopic ellipsometry. The spectra were analyzed within a simple dielectric model. The absorption spectra of annealed, thin, condensed layers of pyrazine, pyridine, and naphthalene on the Ni(111) surface resemble bulk crystal spectra, indicating minimal perturbations due to the metal substrate. Chemisorption of molecules on the Ni(111) surface produced enhanced absorption between 2800{Angstrom} and 3100{Angstrom}. The wide range of adsorbate properties and surface chemistry suggest a modification of the optical response of the metal upon chemisorption. This enhanced optical absorption is attributed to nonvertical interband transitions made possible by loss of translational invariance at the surface.

The longitudinal stability of intense particle bunches is investigated theoretically in the limit of small wall resistivity compared to total reactance. It is shown that both in the absence of resistivity and to lowest order in the resistance that an intense bunch is stable against longitudinal collective modes. An expression is derived for the lowest order instability rate. Application of these results are made to drivers for heavy ion inertial fusion.

We discuss new anode geometries, employing position-dependent charge partitioning, which can be used with microchannel plates, planar proportional counters, and mesh dynode electron multipliers to obtain a two-dimensional position signal from each detected photon or particle. Only three or four anode electrodes and signal paths are required, yet images comprised of a number of detected events have little geometric distortion and the resolution is not limited by thermal noise inherent in resistive sheet anodes. We present an analysis of the geometrical image nonlinearity in the relationship between event centroid location and the charge partition ratios. Fabrication and testing of two wedge-and-strip anode systems are discussed. Images obtained with EUV radiation and microchannel plates that verify the predicted performance of this readout system are shown. We emphasize that the spatial resolution of the wedge-and-strip anode is in no way limited by the coarseness of the anode conductor pattern. The resolution is of the order of 0.4% of the image field size, and could be further improved by adopting low noise signal circuitry. Tradeoffs encountered in the design of practical x-ray, EUV, and charge particle image systems are discussed.

An extensive operational nuclear safety program has been an integral part of the design, startup, and initial operating phases of the Fast Flux Test Facility (FFTF). During the design and construction of the facility, a program of independent safety overviews and analyses assured the provision of responsible safety margins within the plant, protective systems, and engineered safety features for protection of the public, operating staff, and the facility. The program is continuing through surveillance of operations to verify continued adherence to the established operating envelope and for timely identification of any trends potentially adverse to those margins. Experience from operation of FFTF is being utilized in the development of enhanced operational nuclear safety aids for application in follow-on breeder reactor power systems. The commendable plant and personnel safety experiences of FFTF through its startup and ascension to full power demonstrate the overall effectiveness of the FFTF operational nuclear safety program.

Retardation factors (R) have been measured for the transport of /sup 3/H, /sup 95m/Tc, and /sup 85/Sr in WIPP brine using St. Peter, Berea, Kayenta, and San Felipe sandstone cores. If tritium is assumed to have R=1, /sup 95m/Tc has R=1.0 to 1.3 and therefore is essentially not retarded. Strontium-85 has R = 1.0 to 1.3 on St. Peter, Berea, and Kayenta, but R=3 on San Felipe. This is attributed to sorption on the matrix material of San Felipe, which has 45 volume % matrix compared with 1 to 10 volume % for the others. Retardation factors (R/sub s/) for /sup 85/Sr calculated from static sorption measurements are unity for all the sandstones. Therefore, the static and transport results for /sup 85/Sr disagree in the case of San Felipe, but agree for St. Peter, Berea, and Kayenta.

The techniques used for acquisition and preparation of large specimens of rock for laboratory testing depend upon the location of the specimen, the type of rock and the equipment available at the sampling site. Examples are presented to illustrate sampling and preparation techniques used for two large cylindrical samples of granitic material, one pervasively fractured and one containing a single fracture.

Systems which use embedded microcomputers to perform control functions can often double as flexible debugging and maintenance devices by switching in high level language ROMS. This paper describes systems in which such benefits are successfully exploited.

Chemical models of aqueous geochemical systems are usually built on the concept of thermodynamic equilibrium. Though many elementary reactions in a geochemical system may be close to equilibrium, others may not be. Chemical models of aqueous fluids should take into account that many aqueous redox reactions are among the latter. The behavior of redox reactions may critically affect migration of certain radionuclides, especially the actinides. In addition, the progress of reaction in geochemical systems requires thermodynamic driving forces associated with elementary reactions not at equilibrium, which are termed irreversible reactions. Both static chemical models of fluids and dynamic models of reacting systems have been applied to a wide spectrum of problems in water-rock interactions. Potential applications in nuclear waste disposal range from problems in geochemical aspects of site evaluation to those of waste-water-rock interactions. However, much further work in the laboratory and the field will be required to develop and verify such applications of chemical modeling.

The basic concept of the High Yield Lithium Injection Fusion Energy (HYLIFE) reaction chamber involves a falling liquid-metal (lithium) jet array that absorbs 90% of the energy released from inertial confinement fusion reactions. The key element of the chamber that produces the jet array is the nozzle plate. This paper describes the design and analysis of a nozzle plate which can withstand the structural loads and permit the fluid jet array to be reestablished for a 1-Hz fusion reaction frequency. The shape of the nozzle plate and jet array is dictated by considerations of fluid dynamics and neutron-shielding. A vertical jet array, rather than a single annulus, is used because this design enhances fluid momentum interchange and dissipation of the kinetic energy that occurs when the jets disassemble. Less net outward-directed momentum results than with a single liquid annular flow configuration, thus producing lower stresses in the structural components.

A study of transient stress wave propagation in graphite HTGR fuel elements has been undertaken as a step toward developing techniques for the evaluation of seismic impact loads. The objectives of the study were to identify appropriate numerical methods, to understand the influence of the geometry and the multiple holes on the response, and to determine the relative importance of high frequency response and lower mode vibrations. A general review is made of the dynamic contact problem, and the methods available to model impact phenomena and stress wave propagation are evaluated.

Assessment of the post-closure performance of a nuclear waste repository has two basic components: the identification and analysis of potentially disruptive sequences and the pattern of geologic events and processes causing each sequence, and the identification and analysis of the environmental consequences of radionuclide transport and interactions subsequent to disruption of a repository. The AEGIS Scenario Analysis Task is charged with identifying and analyzing potenially disruptive sequences of geologic events and processes. The Geologic Simulation Model (GSM) was developed to evaluate the geologic/hydrologic system surrounding an underground repository, and describe the phenomena that alone, or in concert, could perturb the system and possibly cause a loss of repository integrity. The AEGIS approach is described in this report. It uses an integrated series of models for repository performance analysis; the GSM for a low-resolution, long-term, comprehensive evaluation of the geologic/hydrologic system, followed by more detailed hydrogeologic, radionuclide transport, and dose models to more accurately assess the consequences of disruptive sequences selected from the GSM analyses. This approach is felt to be more cost-effective than an integrated one because the GSM can be used to estimate the likelihoods of different potentially disruptive future evolutionary developments within the geologic/hydrologic system. The more costly …

A microcomputer based system for testing analog charge coupled integrated circuits has been developed. It measures device performance for three parameters: dynamic range, baseline shift due to leakage current, and transfer efficiency. A companion board tester has also been developed. The software consists of a collection of BASIC and assembly language routines developed on the test system microcomputer.

Lawrence Livermore National Laboratory (LLNL) is developing seismic and wind hazard models for the US Department of Energy (DOE). The work is part of a three-phase effort to establish building design criteria developed with a uniform methodology for seismic and wind hazards at the various DOE sites throughout the United States. In Phase 1, LLNL gathered information on the sites and their critical facilities, including nuclear reactors, fuel-reprocessing plants, high-level waste storage and treatment facilities, and special nuclear material facilities. Phase 2 - development of seismic and wind hazard models - is discussed in this paper, which summarizes the methodologies used by seismic and extreme-wind experts and gives sample hazard curves for the first sites to be modeled. These hazard models express the annual probability that the site will experience an earthquake (or windspeed) greater than some specified magnitude. In the final phase, the DOE will use the hazards models and LLNL-recommended uniform design criteria to evaluate critical facilities. The methodology presented in this paper also was used for a related LLNL study - involving the seismic assessment of six commercial plutonium fabrication plants licensed by the US Nuclear Regulatory Commission (NRC). Details and results of this reassessment are documented …

The coupling of lower hybrid waves at the plasma edge by a two waveguide array with self-consistent density modulation is solved numerically. For a linear density profile, the governing nonlinear Klein-Gordon equation for the electric field can be written as a system of nonlinearly modified Airy equations in Fourier k/sub z/-space. Numerical solutions to the nonlinear system satisfying radiation condition are obtained. Spectra broadening and modifications to resonance cone trajectories are observed with increase of incident power.

Numerical studies of the dispersion relation near the lower-hybrid frequency in an inhomogeneous plasma (..delta.. n, ..delta.. T, ..delta.. B) show that portions of an incident lower-hybrid wave spectrum undergo successive but partial mode conversions to warm-plasma waves in the presence of ion cyclotron harmonics. Wave absorption beyond the first mode conversion occurs near an ion cyclotron harmonic where ion Landau damping is enhanced. A second-order dispersion relation numerically in good agreement with the full dispersion relation in the mode conversion region is derived using the condition par. delta D/par. delta k = 0. The mode conversion efficiency at each confluence is evaluated by solving the corresponding differential equation.

In the Bevalac there are several problems that make it very difficult to determine a more precise value for magnetic field. The radial field shape enclosed within the B dot integrating loop on the poletips changes as a function of field strength. The effective magnetic quadrant length also changes as a function of field strength. This causes a major perturbation in the radial position of the equilibrium orbit as well as some uncertainty in the value of the magnetic field. In addition to the magnetic field value, there must be adequate information about the radial position of the closed orbit to determine a precise value for the kinetic energy. If there is sufficient information about the closed orbit, a known effective path length exists for the particle. The transit time of the particle on that path is a time-of-flight measurement. In a circular machine, this time measurement is a frequency measurement which is one of the most precise measurements that can be made. A Hewlett Packard 5360A frequency counter can read to 1 part in 10/sup 6/ for a 0.1 msec read time. This can be extended to 1 part in 10/sup 10/ for longer read time. With time measured …

The DOE program of solar industrial process heat field tests has shown solar energy to be compatible with numerous industrial needs. Both the operational projects and the detailed designs of systems that are not yet operational have resulted in valuable insights into design and hardware practice. Typical of these insights are the experiences discussed for the four projects reviewed. Future solar IPH systems should benefit greatly not only from the availability of present information, but also from the wealth of operating experience from projects due to start up in 1981.

This paper presents a review of experimental upper limits on the branching fractions for various forbidden decay modes of the tau lepton. These are modes which cannot occur in the conventional model in which the tau and its associated neutrino have a unique, conserved lepton number. The limits are based on data acquired by the Mark II Detector Collaboration at SPEAR.

LBL has constructed a facility for testing various performance aspects of residential air-to-air heat exchangers. When used in conjunction with a mechanical ventilation system, a residential heat exchanger permits the adequate ventilation of a residence while recovering most of the energy normally lost during ventilation. By constructing or retrofitting a home so that it has low natural infiltration rates and by using a heat exchanger-ventilation system, a homeowner can save energy, reduce heating and cooling costs, and prevent the buildup of indoor-generated air contaminants. Results obtained on five different residential heat exchangers are presented. The performance criteria and the test facility are described. The performance parameters measured were heat exchanger effectiveness (a measure of heat transfer ability), airstream static pressure drop, and fan system performance. The performance of the five heat exchangers differed greatly. The ability to transfer heat ranged from 43% to 75% of the theoretical maximum. The resistance to air flow varied by a factor of two. One of the heat exchangers was highly susceptible to leakage between airstreams and one had an unstable performance. In the future, additional heat exchangers will be tested, a new test system will be used to measure cross-stream leakage, and the possibility …