When an electrostatic tandem accelerator is used primarily for heavy ion acceleration, numerous communication channels with the high voltage terminal are desirable. The ANL FN tandem operates at a tank pressure of 100 psi SF/sub 6/ at terminal voltages up to 9.5 MeV. A low powered He-Ne laser with 15 percent modulation has been successfully tested in the terminal under normal operating conditions. Such a system allows the transmission of information without the use of light guides. Multistranded light guides did not withstand voltage gradients as low as 0.4 MV/m. Single core light guides with a diameter of 0.5 mm have been successfully operated at voltage gradients in excess of 1.7 MV/m. In addition to the laser a microprocessor has also been tested in the tandem terminal. With suitable protection, an 8080 microprocessor and a programmable ROM operated successfully for several weeks under normal operating conditions.

A 3.4-meter direct-reading spectrograph is being used with an inductively coupled plasma source for the simultaneous determination of Ag, Bi, Cd, Cu, Nb, Ni, Pb, Sn, and W in water samples. We have attached a small digital computer to the system in order to obtain intensity data on each element once a second. After the intensities during a run on a sample have stabilized, the computer records the intensity data and outputs the average concentration for each element. To approach the published detection limits, a peristaltic pump must be used to force the water sample into the usual cross-flow nebulizer. We have studied several different nebulizer designs with the goal of improving efficiency and hence sensitivity. One design, the fritted-disk nebulizer, has an efficiency over 60 percent, as compared with the 5 percent efficiency of the original nebulizer.

The high-temperature diametral expansion and rupture behavior of Zircaloy-4 fuel-cladding tubes have been investigated in vacuum and steam environments under transient-heating conditions that are of interest in hypothetical loss-of-coolant accident situations in light-water reactors. The effects of internal pressure, heating rate, axial constraint, and localized temperature nonuniformities in the cladding on the maximum circumferential strain have been determined for burst temperatures between approximately 650 and 1350/sup 0/C.

The Los Alamos Scientific Laboratory is a large, multidisciplined research laboratory, operated by the University of California for the U.S. Energy Research and Development Administration. An interactive graphic system was developed to integrate design, drafting, testing, analysis, and manufacturing to achieve efficient and effective laboratory-wide services. To accomplish this, the graphic system is hardware independent, and has an associative data base structured on two- and three-dimensional, bounded geometry. The data base allows for levels of attributes that can be attached or deleted and interrogated. This graphic system is described, with emphasis on the efficiencies of graphics and the effect of the associative data base on the ''design--build--test'' cycle. The capability of attaching attributes is explored as the means of bridging the CAD/CAM gap.

Methods are described for monitoring work areas for the presence of primary amines and chemicals readily transformable to primary amines that are potentially carcinogenic. Chemical spot tests for surface monitoring are described and their capabilities and limitations are discussed for monitoring work areas, equipment, and respirators after use in hazardous environments. Methods for work area and personnel decontamination are also described. A list of cancer-suspect amines is included. (CH)

During the past 25 years, a rather rapid evolution has taken place in the design and use of prestressed concrete reactor vessels (PCRVs). Initially the concrete vessel served as a one-to-one replacement for its steel counterpart. This was followed by the development of the integral design which led eventually to the more recent multicavity vessel concept. Although this evolution has seen problems in construction and operation, a state-of-the-art review which was recently conducted by the Oak Ridge National Laboratory indicated that the PCRV has proven to be a satisfactory and inherently safe type of vessel for containment of gas-cooled reactors from a purely functional standpoint. However, functionalism is not the only consideration in a demanding and highly competitive industry. A summary is presented of the important considerations in the design and analysis of multicavity PCRVs together with overall conclusions concerning the state of the art of these vessels.

Queueing network models of computing systems are becoming increasingly popular because of their robustness and ease of solution. The impact of resource request patterning upon these models is presently not well understood. This paper proves the counter-intuitive fact that the effect of both holding time and routing patterning upon the performance measures for the important class of local balance models is nil. A study of a larger class of models, over a parameter space typical of models of computing systems, reveals that the impact of patterning of resource requests upon performance measures is negligible. This conclusion has important consequences for understanding the robustness of queueing network models of computing systems and for the level of detail necessary for accurate workload characterization. The practical consequences of this result to performance analysis of computing systems are considered. 4 figures, 5 tables.

A well known property of phase controlled rectifiers with pulsed inductive loads is the ability to advance firing angles from full rectification (positive voltage) to full inversion (negative voltage). Though these properties have been effectively used in the Main Ring power supplies, they have not been extensively utilized for beam line magnet power supplies. Modifications to permit advancing phase angle sufficiently to permit inversion were made on TransRex 500 kW power supplies and Ling 55 kW power supplies. The objective of these modifications was to rapidly reduce the current in magnet loads to zero upon command. The modifications required and the performance of the power supplies are discussed.

Radiation protection/shielding design of a nuclear facility requires a coordinated effort of many engineering disciplines to meet the requirements imposed by regulations. The system approach to Clinch River Breeder Reactor Plant (CRBRP) radiation protection is described, and the program developed to implement this approach is defined. In addition, the principal shielding design problems for LMFBR nuclear reactor systems are discussed in relation to LWR nuclear reactor system shielding designs. The methodology used to analyze these problems in the U.S. LMFBR program, the resultant design solutions, and the experimental verification of these designs and/or methods are discussed.

A description is given of the design and realization of an rf transmitter system capable of driving very fast modulation envelopes (12 ns to 20 ns) representative of analog signals through long coaxial cables. The transmitter employs two amplitude-modulated carriers to transmit the amplitude and the polarity of the input drive signal simultaneously, via frequency-division multiplexing over an 800 MHz spectrum in the vhf and uhf bands.

Future need for fossil fuels may lead to an exploitation of Western coal and oil shale at the expense of the traditional clean air and clear skies of the West. This report evaluates the prospects for future changes in western air quality, the constraints imposed on western energy development by air quality regulations, and the impacts of that development.

In the study of disordered alloys, theorists have stated the physics of the problem in terms of an integral equation and analyzed this equation by techniques developed in the quantum mechanical theory of scattering. The application of the scattering theory approach to the computation of the effective dielectric constant of a polycrystal is discussed. The problem is framed in the form of an integral equation. Several well-known intuitive approximations are recovered, and the connection of the approximations to perturbation theory is indicated. (RWR)

Nitrate assimilation requires the function and regulation of three processes, namely the uptake and translocation of nitrate from the environment into the cell, the reduction of the anion to ammonium via nitrate and nitrite reductases, and the incorporation of the reduced nitrogen into amino acid precursors. All three processes are anabolic and endothermic and, consequently, must be thermodynamically coupled to catabolic and exothermic reactions. While most of the recent research on nitrate assimilation has focused on one or the other of these processes individually, less attention has been given to describing the energy sources required for their function and the regulation of the processes by thermodynamic coupling.

A simple method for estimating the solubility of TATB in various solvents is presented. We consider it unlikely that a solvent will be found in which TATB is more soluble than 0.1 percent (w/v). Exceptions are the so-called superacids in which the solubility of TATB exceeds 20 percent (w/v).

A solid sphere of 303 stainless steel was subjected to a multi-megabar shock pressure in a spherically convergent high explosive system. The recovered stainless steel wall was subjected to a metallurgical examination to determine the microstructural features developed in the ball. The most recent examination was prompted by the desire to determine whether the solidification rates developed in the ball (estimated to be 10/sup 8/ to 10/sup 10/ K/sec by the pressure release in the trailing edge of a shock were actually developed. The cooling rate determinations were to be made by observing the dendrite arm spacing (DAS) developed in the solidified metal. The examination reported in this paper has yielded inconsequential results regarding the cooling rate. Estimates of dendrite arm spacing were made and a solidification rate of greater than 10/sup 4/ K/sec was estimated. The alloy used in this experiment, 303 stainless steel, is chemically too complex to develop easily interpreted results. We intend to repeat these experiments using simpler binary alloys and pure metals.

Measurements of release velocities in various samples of SiO/sub 2/ shocked into the pressure range of 47-67 GPa are reported. The first direct observation of a longitudinal release wave in SiO/sub 2/ at these high pressures is reported. The resulting sound speed data along the Hugoniot, combined with the Hugoniot, permit a calculation of the Gruneisen parameter along the Hugoniot. Because the pressure-temperature region of the experiments approximates middle mantle conditions, the longitudinal and bulk velocity measurements for SiO/sub 2/ have immediate implications for composition constraints to fit seismic profiles of sound velocities. (GHT)

The large amount of field and laboratory data collected by the Hydrogeochemical and Stream Sediment Reconnaissance Program contractors of the National Uranium Resource Evaluation (NURE) Program necessitates the use of computerized data verification procedures. The Oak Ridge National Laboratory data verification procedures consist of computerized checks of the validity of codes for every field of data reported. The verification procedures are part of an overall data evaluation system. Sample locations are checked from computerized plots of locations. Laboratory data ara analyzed statistically, and unusual samples are identified and selectively reanalyzed in the laboratory. The final verification step is the evaluation of the data by geologists to ensure the overall consistency of the reported results. The computerization of these procedures enables a rapid verification process. The following sections present an explanation of each aspect of data collection and a brief description of the data verification procedures used by the Oak Ridge program.

The LASL Hot Dry Rock Geothermal Energy Project is investigating methods to extract energy at useful temperatures and rates from naturally heated crustal rock in locations where the rock does not spontaneously yield natural steam or hot water at a rate sufficient to support commercial utilization. Several concepts are discussed for application to low and high permeability formations. The method being investigated first is intended for use in formations of low initial permeability. It involves producing a circulation system within the hot rock by hydraulic fracturing to create a large crack connecting two drilled holes, then operating the system as a closed pressurized-water heat-extration loop. With the best input assumptions that present knowledge provides, the fluid-flow and heat-exchange calculations indicate that unpumped (buoyant) circulation through a large hydraulic fracture can maintain a commercially useful rate of heat extraction throughout a usefully long system life. With a power cycle designed for the temperature of the fluid produced, total capital investment and generating costs are estimated to be at least competitive with those of fossil-fuel-fired and nuclear electric plants. This paper discusses the potential of the hot dry rock resource, various heat extraction concepts, prediction of reservoir performance, and economic factors, and …

A computer program is used with a direct viewing (CRT) terminal and printout unit to provide current information on all maintenance tasks at the Savannah River Laboratory. The data, available daily to foremen, scheduling personnel, and customers, are maintained in an on-line computer program, MIACJR. Interaction through the CRT terminal allows daily revisions as work progresses, jobs are initiated or completed, or other job changes are made (such as priority). Approximately 2000 jobs, open at any one time, for 22 customer groups are monitored so that 11 craft groups may work in an orderly and efficient manner. 3 figures.

A generalized shielding methodology has been developed in the U.S.A. that is adaptable to the shielding analyses of all reactor types. Thus far used primarily for liquid-metal fast breeder reactors, the methodology includes several component activities: (1) developing methods for calculating radiation transport through reactor-shield systems; (2) processing cross-section libraries; (3) performing design calculations for specific systems; (4) performing and analyzing pertinent integral experiments; (5) performing sensitivity studies on both the design calculations and the experimental analyses; and, finally, (6) calculating shield design parameters and their uncertainties. The criteria for the methodology are a 5 to 10 percent accuracy for responses at locations near the core and a factor of 2 accuracy for responses at distant locations. The methodology has been successfully adapted to most in-vessel and ex-vessel problems encountered in the shield analyses of the Fast Flux Test Facility and the Fast Flux Test Facility and the Clinch River Breeder Reactor; however, improved techniques are needed for calculating regions in which radiation streaming is dominant. Areas of the methodology in which significant progress has recently been made are those involving the development of cross-section libraries, sensitivity analysis methods, and transport codes.

Models of the thermal evolution of the moon and the terrestrial planets suggest that basin-forming impacts occurred when the planets had partially molten interiors overlain by thickening lithospheres, comparable in thickness to the basin radii. The effects of large impacts on planetary surfaces were investigated using a Lagrangian computer program which treats shock wave propagation and includes the effects of material strength, elastic-plastic behavior and material failure. The computer code and some physical details of the numerical techniques are described, and the results of several initial calculations are reported. The global seismic effects for cratering energies (10/sup 24/ and 10/sup 25/ J) intermediate between the Copernicus and Imbrium events on the moon, are studied and the phenomenologies for assumed solid and molten planetary interiors are compared. The principal results are as follows: (1) Far-field effects are largely independent of cratering mechanisms (e.g., simulated impact vs buried explosion). (2) Antipodal seismic effects are significantly enhanced by focusing and are of substantial magnitude. Vertical ground motion may be on the order of kilometers, and accelerations approach one lunar-g. (3) The most violent activity occurs at significant depth beneath the antipode, considerably after the passage of the initial compressive/rarefactive shock wave, and results …

Measurements of the K X-ray absorption and emission edges of Li are reported. They were made with the same spectrometer at the NBS storage ring and serve to establish a 0.1 eV separation between the edges with no possibility of instrument calibration error. These results are compared with recent theories of Almbladh and Mahan describing the effects of incomplete phonon relaxation about the core hole. It is concluded that these theories give a satisfactory explanation of the data.

The ground state for adsorbed monolayers on crystalline substrates is shown to involve a definite relative orientation of the substrate and adsorbate crystal axes, even when the relative lattice parameters are incommensurate. The rotation angle which defines the structure of the monolayer-substrate system is determined by the competition between adsorbate-substrate and adsorbate-adsorbate energy terms, and is generally not a symmetry angle. Numerical predictions are presented for the rare gas-graphite systems, whose interaction potentials are rather well known. Recent LEED data for some of these systems appear to corroborate these predictions.

The oxidation of core graphite by steam of air represents a problem area of significant concern in safety analyses for the high temperature gas cooled reactor (HTGR). Core and core-support graphite integrity and strength deteriorate with oxidation of the graphite, and oxidation furthermore could affect the rate of fission product release under upset conditions. Consequently, modeling of core response during steam or air ingress conditions requires an expression for the rate of graphite interaction with those impurities. The steam--graphite reaction in particular is a complex interaction of mass transport within the graphite with chemi-sorption and reaction on accessible surfaces; experimental results from graphite to graphite are highly variable, and the description of the reaction is not yet completely consistent. A simple etch pit model relating surface area to burnoff has been proposed and shown to provide reasonable correlation with experimental data obtained from steam oxidation studies of nuclear grade H-327 graphite. Unaccounted differences between theory and experiment arise at burnoffs exceeding 3 to 5 percent. The model, while not complete nor comprehensive, is consistent with experimental observations of graphite oxidation by O/sub 2/(air), CO/sub 2/, or H/sub 2/O, and could have some utility in safety analysis.