One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed.

We report on our investigation of the Rayleigh-Taylor (R-T) and Kelvin-Helmholtz (K-H) instabilities in laser ablatively accelerated targets for single mode perturbations for a series of wavelengths in the parameter regime 1/2 less than or equal to lambda/..delta..R less than or equal to 10, where lambda is the wavelength of the perturbation and ..delta..R is the cold foil thickness. We find linear growth rates well below classical values (by a factor on the order of 3 to 4). We also find a cutoff in the growth rates for wavelengths less than the foil thickness. The striking result is the dominance of nonlinear effects; i.e., the K-H instability, for short wavelength perturbations. Although the linear growth rates increase as k/sup 1/2/ up to the cutoff, the K-H rollup dominates at large k, drastically reducing the penetration rate of the dense spike below its free fall value and effectively doubling the aspect ratio of the foil. In other words, it is the long wavelength perturbations that are most effective in destroying the symmetric implosion of the shell.

From abstract: "This study was made to describe the distribution of inorganic nitrogen and other chemical constituents and nitrogen-using bacteria in the unsaturated zone, to relate nitrogen occurrences, in a general way, to present and historical land use, and to attempt to predict nitrogen concentrations in ground water after recharge" within the Highland-East Highlands area of San Bernardino County, California. It includes maps, graphs, and tables.

A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation were derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings were used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Corresponding average deviations for five rare-earth nuclei are 47 keV and 7%. Several applications of this modeling technique are discussed. 18 refs., 5 figs., 4 tabs.

This report is the first in the series of bibliographies supporting the efforts at the Brookhaven National Laboratory ALARA Center on dose reduction at DOE facilities. Abstracts for this bibliography were selected from proceedings of technical meetings, journals, research reports, and searches of the DOE Energy Data Base. The abstracts included in this report relate to operational health physics as well as other subjects which have a bearing on dose reduction. Facilities covered include: radioactive waste, uranium enrichment, fabrication, unirradiated fissile materials storage, irradiated fissile material storage, reprocessing, decommissioning, recovery, hot laboratories, tritium production, reactors (research, test and production but not power reactors), and accelerators. We have also included material in improved design, materials selection, planning, and other topics which are related to dose-reduction efforts. The report contains 68 abstracts as well as subject and author indices.

None

The development of hydrothermal energy for direct heat applications is being aided by twenty-two demonstration projects that are funded on a cost-sharing basis by the US Department of Energy, Division of Geothermal Energy. These projects are designed to demonstrate the technical and economic feasibility of the direct use of geothermal heat in the United States. Twelve of these projects are administered by the DOE-Idaho Operations Office with technical support from EG and G Idaho, Inc. Engineering and economic data for these projects are summarized in this paper. The data and experience being generated by these projects will be an important basis for future geothermal direct use projects.

For application in plasma heating, fueling, and current drive of magnetic fusion devices, high current negative deuterium ion sources for intense neutral beam injectors are being developed using efficient production of negative hydrogen isotope ions on low work function metal surfaces imbedded in hydrogen plasmas. In order to investigate the correlation between work function and negative hydrogen ion production, photoelectron emission from a cesiated metal surface, which is immersed in a hydrogen plasma with an electron density less than 5 x 10/sup 10//cc, was measured in the photon energy range of 1.3 to 4.1 eV. The work function determination was based on Fowler's analysis, and at the optimum coverage a work function of less than 1.5 eV was observed for a Cs-Cu surface. Measured values of work functions for different Cs coverages were compared to the negative hydrogen currents produced at the metal surface in the discharge; the surface production of negative hydrogen ion current is monotonically increasing with decreasing work function.

An investigation was carried out to determine the effect of rapid solidification on the weld metal microstructure of austenitic stainless steels and its implication on the ferrite constitution diagram. A wide variety of stainless steels were laser welded at different welding speeds and laser power levels. Results indicate that both weld pool cooling rate and the postsolidification solid state cooling rates have a profound effect on the microstructures. For the steels investigated, the microstructures ranged from duplex austenite (..gamma..) + ferrite (delta) to fully austenitic or fully ferritic. These microstructures were found to be sensitive to both cooling rates and composition. The observed results are rationalized based on rapid solidification theory. This investigation indicates that solidification rates and postsolidification cooling rates have a profound effect on the observed microstructures, thus making it impossible to predict the microstructures of rapidly cooled weld metal from the conventional constitution diagrams. The influence of the observations made in this investigation on the Schaeffler diagram is demonstrated, and possible corrections to the constitution diagram incorporating the cooling rate effects are proposed. 23 refs., 17 figs., 4 tabs.

The cross section for the /sup 7/Li(n,n't)/sup 4/He reaction is measured at an average neutron energy of 14.74 MeV, with a resolution of 0.324 MeV, relative to the /sup 238/U neutron-fission cross section. Tritium activities for the irradiated lithium-metal samples (enriched to 99.95% in /sup 7/Li) are deduced using a liquid-scintillation counting method which relies upon the tritiated-water standard from the US National Bureau of Standards. The measured cross section ratio of /sup 7/Li(n,n't)/sup 4/He to /sup 238/U neutron fission is 0.2523 (+- 2.2%). The derived /sup 7/Li(n,n't)/sup 4/He reaction cross section is 0.301 (+- 5.3%) barn, based on the ENDF/B-V value of 1.193 (+- 4.8%) barn for the /sup 238/U neutron-fission cross section. 59 references.

This volume contains the following sections: (1) fueling systems; (2) blanket; (3) alternative blanket concepts; (4) halo scraper/direct converter system study and final conceptual design; (5) heat-transport and power-conversion systems; (6) tritium systems; (7) minimars air detritiation system; (8) appropriate radiological safety design criteria; and (9) cost estimate. (MOW)

Progress at LAMPF is the semiannual progress report of the MP Division of the Los Alamos National Laboratory. The report includes brief reports on research done at LAMPF by researchers from other institutions and Los Alamos divisions.

This report investigates the likely rates and the potential range of future CO/sub 2/ emissions, combined with knowledge of the global cycle of carbon, to estimate a possible range of future atmospheric CO/sub 2/ concentrations through the year 2075. Historic fossil fuel usage to the present, growing at a rate of 4.5% per year until 1973 and at a slower rate of 1.9% after 1973, was combined with three scenarios of projected emissions growth ranging from approximately 0.2 to 2.8% per year to provide annual CO/sub 2/ emissions data for two different carbon cycle models. The emissions scenarios were constructed using an energy-economic model and by varying key parameters within the bounds of currently expected future values. The extreme values for CO/sub 2/ emissions in the year 2075 are 6.8 x 10/sup 15/ and 91 x 10/sup 15/ g C year/sup -1/. Carbon cycle model simulations used a range of year - 1800 preindustrial atmospheric concentrations of 245 to 292 ppM CO/sub 2/ and three scenarios of bioshere conversion as additional atmospheric CO/sub 2/ source terms. These simulations yield a range of possible atmospheric CO/sub 2/ concentrations in year 2075 of approximately 500 to 1500 ppM, with a median of …

From August 1981 through January 1982, the Los Alamos Safeguards and Security Program was involved in many activities that are described in the four parts of this report: Nuclear Facility Safeguards Support, Security Development and Support, Safeguards Technology Development, and International Support. Part 1 covers those efforts of direct assistance to the Department of Energy and the Nuclear Regulatory Commission licensee facilities. This assistance varies from consultation on materials accounting problems, through development of specialized techniques and devices, to comprehensive participation in the design and implementation of advanced safeguards systems. In addition, a series of training courses in various aspects of safeguards helps make the technology more accessible to those who must apply it. Part 2 concerns a relatively new set of activities at Los Alamos aimed at the security of information and computer systems. The focus this period has been on furthering the development of the Computer Security Center, which provides the basis for encouraging and disseminating the emerging technology. Part 3 describes the development efforts that are essential to continued improvements in the practice of safeguards. Although these projects are properly classified as developmental, in every case they are directed ultimately at recognized problems that commonly occur in …

Progress is reported in the following areas: heat extraction from hydrothermal reservoirs; radon reservoir engineering; well test analysis and bench scale experiments; field applications; workshop, seminars, and technical information; reinjection technology; and seismic monitoring of vapor/liquid interfaces. (MHR)

The measurement of the following thermophysical properties of Utah tar sands is in progress: thermal conductivity, specific heat relative permeability, and viscosity (of the recovered bitumen). During the report period (October 1, 1978 to November 1, 1979), experimental procedures have been developed and a basic data set has been measured. Additionally, standard core analysis has been performed for four drill sites in the Asphalt Ridge, Utah area.

Reservoir definition research consisted of well test analysis and bench-scale experiments. Well testing included both single-well pressure drawdown and buildup testing, and multiple-well interference testing. The development of new well testing methods continued to receive major emphasis during the year. Work included a project on multiphase compressibility, including the thermal content of the rock. Several projects on double-porosity systems were completed, and work was done on relative-permeability. Heat extraction from rock will determine the long-term response of geothermal reservoirs to development. The work in this task area involved a combination of physical and mathematical modeling of heat extraction from fractured geothermal reservoirs. International cooperative research dealt with adsorption of water on reservoir cores, the planning of tracer surveys, and an injection and tracer test in the Los Azufres fields. 32 refs.

The objective of this project was to develop and evaluate the effectiveness of physical and chemical barriers designed to prevent plant and animal breachment of uranium mill tailings containment systems for an extended period of time. A polymeric carrier/biocide delivery system was developed and tested in the laboratory, greenhouse and field. A continuous flow technique was established to determine the release rates of the biocides from the PCD systems; polymeric carrier specifications were established. Studies were conducted to determine effective biocide concentrations required to produce a phytotoxic response and the relative rates of phytotoxin degradation resulting from chemical and biological breakdown in soils. The final PCD system developed was a pelletized system containing 24% trifluralin, 18% carbon black and 58% polymer. Pellets were placed in the soil at the Grand Junction U-tailings site at one in. and two in. intervals. Data obtained in the field determined that the pellets released enough herbicide to the soil layer to stop root elongation past the barrier. Physical barriers to subsurface movement of burrowing animals were investigated. Small crushed stone (1 to 1 1/2 in. diameter) placed over asphalt emulsion and multilayer soil seals proved effective as barriers to a small mammal (ground squirrels) …

This report aims to provide an insight about reasons why educational markets are under-producing educational software, and what thoughtful, practical remedies can be employed to bring the production of educational software up to the socially desirable level.

Quarterly report of the Argonne National Laboratory Chemical Engineering Division regarding activities related to properties and handling of radioactive materials, operation of nuclear reactors, and other relevant research.

The well-known Maxwell-Vlasov equations that describe a collisionless plasma are cast into Hamiltonian form. The dynamical variables are the physical although noncanonical variables E, B and f. We present a Poisson bracket which acts on these variables and the energy functional to produce the equations of motion.

An indirect method of laser-based equation of state studies, which utilizes shock waves generated by laser-accelerated projectiles rather than ablation shocks from direct laser irradiation of the sample under investigation, is proposed and examined theoretically. We derive simple formulas for the minimum thickness and maximum speed of laser-accelerated disks, comparing them with results of Nd-laser experiments conducted by the Naval Research Laboratory. Our calculations indicate that disks can be accelerated to velocities above 10/sup 7/ cm/s using a wide choice of laser parameters (pulse duration, energy, intensity, wavelength, etc.). The use of shorter wavelengths, e.g., a KrF(0.25 ..mu..m) laser rather than Nd (1.06 ..mu..m), allows thicker disks to be accelerated and faster velocities to be attained, approximately in the ratio (lambda/sub L/(Nd)/lambda/sub L/(KrF))/sup 1/3/ approx. = 1.6. One-dimensional Lasnex computer calculations indicate that the laser-accelerated disk constitutes a useful flyer plate even while disassembling under the force of the laser ablation shock. The calculations predict that the shockwave the projectile disk generates in a second (impact) disk located a suitable distance away has a greater amplitude than the laser shock and is considerably more steady, exhibiting little decay in propagating through the second disk.

Fourteen sections, including five subsections, of the final report covering work done between June 1, 1975 to July 31, 1980 on research programs in coal gasification and liquefaction have been entered individually into EDB and ERA. (LTN)

This document records the proceedings of a symposium on flow and transport processes in partially saturated groundwater systems, conducted at the Battelle Seattle Research Center on March 22-24, 1982. The symposium was sponsored by the US Nuclear Regulatory Commission for the purpose of assessing the state-of-the-art of flow and transport modeling for use in licensing low-level nuclear waste repositories in partially saturated zones. The first day of the symposium centered around research in flow through partially saturated systems. Papers were presented with the opportunity for questions following each presentation. In addition, after all the talks, a formal panel discussion was held during which written questions were addressed to the panel of the days speakers. The second day of the Symposium was devoted to solute and contaminant transport in partially saturated media in an identical format. Individual papers are abstracted.