The use of ab initio molecular orbital calculations to aid in the characterization, i.e., structures and energies, of metal halide complexes present in high temperature salt vapors has been investigated. Standard LCAO-SCF methods were used and calculations were carried out using the minimal STO-3G basis set. The complexes included in this study were Al/sub 2/F/sub 6/, Al/sub 2/Cl/sub 6/, AlF/sub 3/ NH/sub 3/, AlCl/sub 3/ NH/sub 3/, and AlF/sub 3/ N/sub 2/. The Al/sub 2/X/sub 6/ complexes are found to have D/sub 2h/ symmetry in agreement with most experimental results. A planar form was found to be considerably higher in energy. The AlX/sub 3/ NH/sub 3/ complexes are found to have C/sub 3v/ symmetry with a small barrier to rotation about the Al-N axis. The AlF/sub 3/ N/sub 2/ complex is found to be weakly bound together with a binding energy of -8.2 kcal/mole at the STO-3G level.

This paper describes the analyses performed for the PINEX-2 experiment to calculate the ejection of molten fuel into the reflector and fission gas plenum for an internally-vented fuel pin during a simulated 5$/s transient overpower excursion. The LAFM code was used to predict the transient fuel melting and fission gas release, and the HOTPIM and FUMO-T codes were used to predict the fuel ejection. The analytical results were compared with initial data from both the Pinhole-TV Imaging System and the fast-neutron hodoscope, as well as post-transient examinations of the fuel pin.

A review is given of the properties of a general class of polynomials in the boson operators which were found useful for obtaining the explicit unitary irreducible representations of the unitary group itself, and to show how these same polynomials provide a unified approach for obtaining the explicit solutions to several classic problems in physics and chemistry. 24 references. (JFP)

An automated facility remotely and automatically analyzes soil, water, and sediment samples for uranium. The samples travel through pneumatic tubes and switches to be first irradiated by neutrons and then counted for resulting neutron and gamma emission. Samples are loaded into special carriers, or rabbits, which are then automatically loaded into the pneumatic transfer system. The sample carriers have been previously coded with an identification number, which can be automatically read in the system. This number is used for correlating and filing data about the samples. The transfer system, counters, and identification system are controlled by a network of microprocessors. A master microprocessor initiates routines in other microprocessors assigned to specific tasks. The software in the microprocessors is unique for this type of application and lends flexibility to the system.

A combined air particulate sampler and elemental sulfur analyzer was developed for continuous monitoring of fine particulate sulfur. It consists of a dichotomous sampler, continuous tape membrane filter system, and single-channel wavelength dispersive x-ray fluorescence spectrometer. The unit operates automatically under microprocessor control and is designed to be transportable to remote sampling sites. Calibration data are retained within the microprocessor program and the concentrations are available shortly after the completion of the sampling period. Operating results are summarized briefly.

Neutron-induced capture cross sections for the ground states and first isomeric states of /sup 93/Nb, /sup 94/Nb and /sup 95/Nb were studied from the resolved resonance region to 4 MeV via statistical model calculations. The production of isomers was included. Inelastic scattering cross sections and gamma-ray production spectra were also calculated. The anti GAMMA/ sub ..gamma..//D ratios were derived from gamma-ray strength function systematics. Total capture cross sections on the ground states are found to be within a factor of two of each other. Capture cross sections on the isomeric targets are important as well, not only because of their magnitude but also because of the significant population of these isomeric levels by inelastic scattering. 10 references.

Those areas or cells within LMFBR plants that contain radioactive sodium systems are provided with certain design features which eliminate or limit potential sodium/concrete reaction and thus protect the concrete structure in the event of an accidental sodium spill. The principal design feature within these cells that controls sodium spill effects is the cell liner system. The description, requirements and analysis of such a system design for the Clinch River Breeder Reactor Plant (CRBRP) is presented in this paper. The information included in this paper can be utilized directly or can formulate the basis for design of cell liners for commercial scale LMFBR's or future large scale liquid metal test facilities.

Close-coupled analytical methods are being developed at the Hanford Engineering Development Laboratory (HEDL) for application to alternate breeder reactor fuels fabrication. Close-coupled analyses are performed in automated, off-line, nearly real-time configurations to reduce operator radiation exposure while providing rapid results to allow feedback control of process parameters. Methods are being developed for fuels assay (U--Pu--Th), oxygen-to-metal ratio, fluoride and chloride, high-temperature off gas, feed-power particle size, sulfur and carbon, nitrogen, and moisture analyses with analytical turnaround times of 10 minutes or less. The analytical methodology, current status, and proposed development for each of these methods will be discussed.

The Closed Loop In-Reactor Assembly (CLIRA) is a test vehicle for in-core material and fuel experiments in the Fast Flux Test Facility (FFTF). The FFTF is a fast flux nuclear test reactor operated for the Department of Energy (DOE) by Westinghouse Hanford Company in Richland, Washington. The CLIRA is a removable/replaceable part of the Closed Loop System (CLS) which is a sodium coolant system providing flow and temperature control independent of the reactor coolant system. The primary purpose of the CLIRA is to provide a test vehicle which will permit testing of nuclear fuels and materials at conditions more severe than exist in the FTR core, and to isolate these materials from the reactor core.

Computational models have been constructed for the Princeton Large Torus (PLT), the Poloidal Divertor Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR). These models have been calibrated by comparison with current experiments and used to predict plasma parameters and delineate favorable modes of operation for future experiments. The models for PLT emphasize plasma transport and neutral beam injection heating. The models for PDX emphasize the capability of divertors for impurity and recycling control in intense neutral-beam-heated tokamaks, as well as optimization of the MHD properties of divertor-equipped tokamaks. The TFTR calculations stress the fusion aspects of a large, circular cross-section D-T tokamak with intense neutral beam injection.

Equipment is being developed to economically remove contaminated concrete surfaces in nuclear facilities. To be effective this equipment should minimize personnel radiation exposure, minimize the volume of material removed, and perform the operation quickly with the least amount of energy. Several methods for removing concrete surfaces are evaluated for use in decontaminating such facilities. Two unique methods especially suited for decontamination are described: one, the water cannon, is a device that fires a high-velocity jet of fluid causing spallation of the concrete surface; the other, a concrete spaller, is a tool that exerts radial pressure agains the sides of a pre-dilled shallow cylindrical hole causing spallation to occur. Each method includes a means for containing airborne contamination. Results of tests show that these techniques can rapidly and economically remove surfaces, and leave minimal rubble for controlled disposal.

Nb/sub 3/Ge films fabricated by magnetron sputtering at substrate temperatures T/sub s/, from 600 to 850/sup 0/C and film thicknesses of 1 to 5 ..mu..m have been analyzed with respect to transition temperature T/sub c/, critical current density as a function of applied field J/sub c/(H), and grain size. J/sub c/ at 5Tesla shows a strong dependence on T/sub s/, decreasing by more than an order of magnitude as T/sub s/ increases from 700 to 815/sup 0/C. This decrease will be related to grain diameter D. Results will be presented which suggest a lower J/sub c/(H) in thicker films prepared at a fixed T/sub s/ is caused by increased grain diameters as the films grow in thickness. Evidence will be presented showing these results to be consistent with grain boundaries being the dominant pinning mechanism in these films.

Rate constants for the photodissociation of C/sub 2/F/sub 5/Cl as well as the yield of C/sub 2/F/sub 4//sup +/ were measured. The dynamics of the two dissociation channels was studied by measuring the angular and velocity distributions of the products. 2 references. (JFP)

A cryogenic vacuum pumping panel has been in operation at the 88-inch cyclotron since 1974. The nude pumping panel is located in the acceleration chamber. The pumping surface consists of tubing cooled to 20/sup 0/K by a closed loop helium refrigeration system. The pumping surfaces are shielded from radiation heat loads and water vapors by liquid nitrogen cooled baffles. The panel was designed for an average pumping speed of 14,000 liters/sec. for air. This approximately tripled the total effective pumping on the acceleration chamber from the existing diffusion pumped system, significantly reducing charge exchange losses of heavy ions during acceleration. Design, installation and performance characteristics are described.

A two year design study has been completed for medical ion accelerators with beams of sufficient range and intensity for therapy. The particles of main interest were ions between carbon and neon, but the generation of proton and neutron beams was studied also. Cyclotrons appear to be good injectors for a heavy ion medical synchrotron, particularly if neutron and/or isotope production is desired as well. They also offer a competitive solution for proton beams of 250 MeV. A superconducting cyclotron design for 380 MeV/u carbon was worked out, but a synchrotron for heavy ion beams of 400 to 600 MeV/u and 5 x 10/sup 9/ particles/sec was found to be more economical and flexible.

Bronze-processed Nb/sub 3/Sn composite wire conductors exhibit changes in their superconducting parameters when strained in tension. This paper describes a detailed study of the effect of strain on critical current and an analysis by optical and SEM techniques of crack formation in the Nb/sub 3/Sn layer under strain. The effect of strain history on both reversible and irreversible changes in critical current and the roles of differential thermal contraction induced residual strains and of Nb/sub 3/Sn cracking are discussed.

Special maintenability problems associated with the design and operation of sodium cooled reactor plants are discussed. Some examples of both good and bad design practice are introduced from the design of the FFTF plant and other plants. Subjects include design for drainage, cleaning, decontamination, access, component removal, component disassembly and reassembly, remote tooling, jigs, fixtures, and design for minimizing radiation exposure of maintenance personnel. Check lists are included.

The air in certain work areas at the Oak Ridge Gaseous Diffusion Plant is monitored for selected radionuclides to assure safety from toxic effects to personnel in the area. Some of the radionuclides that are determined are shown with their Radiation Protection Standard (RPS) values by means of a table. The RPS is the maximum average airborne contamination to which personnel may be exposed for one week without respiratory protection and is expressed as disintegrations per minute (dpm) per cubic meter (m/sup 3/) of air. It is desirable to make reliable measurements at a level which is 10% of the RPS to ensure that the detection limits are well below the RPS. Thorium, neptunium, plutonium, and uranium all have alpha emitting isotopes and it is their alpha activity which is measured. Results are tabulated.

An application of high resolution electron microscopy, which distinguishes atomic level details in both the boundary and growth front regions of grain boundary precipitates and indicates the structure and mechanisms responsible for enhanced reaction kinetics, is described. (GHT)

As indicated by tests on several cameras, the dynamic range of the Lawrence Livermore Laboratory streak-camera system appears to be about two orders of magnitude greater than those reported for other systems for 10- to 200-ps pulses. The lack of a fine mesh grid in the RCA streak tube used in these cameras probably contributes to a lower system dynamic noise and therefore raises the dynamic range. A developmental tube with a mesh grid was tested and supports this conjecture. Order-of-magnitude variations in input slit width do not affect the spot size on the phosphor or the dynamic range of the RCA tube.

The major activities during FY 1978 involved improvements of the experimental test facility. The facility is being equipped with simulators for the heat from solar collectors and for the building load, driven by the same input meteorological data. Instrumentation has been added to the facility, and heat balance tests using solar collector and simulator heat input have been carried out. In addition, heat loss experiments have been conducted without any heat input or load. The TRNSYS computer program was employed to predict system performance and the results were compared with experimental measurements.

The success of any Inertial Confinement Fusion system for the production of useful power depends critically on the production of suitable targets. This is true whether the arrangement is that proposed by Nuckolls et al. or some other arrangement. The target must have characteristics such as material composition, structure, and surface finish which are tailored to the laser pulse length, energy, peak and average power and pulse shape. To provide useful power on a continuous basis, it is likely that the repetition rate will be 1.0 to 10 per second. Thus, in a 24 hour running period 864,000 targets may be necessary and one must be placed at the focal point of the laser every tenth of a second. For economic operation it is necessary that the targets be produced at costs of less than $1.00 per target.

The policy discussion following the Oil Embargo was clouded with fears of a return to a primitive existence based on drastically reduced energy inputs to society, or, on the other hand, an abandoning of environmental goals, allegedly a major barrier to development of new energy supplies. Often the energy use associated with environmental improvements was cited as a reason for expanding energy supplies, as if to say that a conflict existed between a clean environment and reductions in energy use. Or it was argued that a relaxation of environmental goals would lower the direct costs of harvesting and using energy and thereby alleviate the need for energy conservation. It has also been argued that the geopolitics of energy alone will force us to substitute riskier or ''dirtier'' energy sources for relatively clean oil and gas. Indeed, there is no question that the relationship among energy, the environment, and economic well-being is complicated. This essay sorts out many of the confusing aspects in order to show how goals relating to the efficient use of energy are aligned both with traditional economic goals and with modern environmental goals. To do this the author analyzes in depth the role of energy in the …

This project is directed toward data collection and evaluation of the performance of the largest working, salt-gradient, solar pond in the world.