A design is presented that suggests that a negative ion neutral beam based on direct extraction is applicable to TNS, assuming technological advancements in several areas. Improvements in negative ion sources, direct energy conversion of charged beams, and high speed cryogenic pumping are needed. The increase in efficiency over a positive ion system and the encouraging results of the first attempt at a total design justify increased effort in the development of the above mentioned areas.

The conclusion of this work is that a bundle divertor, using an improved method of designing the magnetic field configuration, is feasible for the Demonstration Tokamak Hybrid Reactor (DTHR) investigated by Westinghouse. The most significant achievement of this design is the reduction in current density (1 kA/cm/sup 2/) in the divertor coils in comparison to the overall averaged current densities per tesla of field to be nulled for DITE (25 kA/cm/sup 2/) and for ISX-B/sup 2/ (11 kA/cm/sup 2/). Therefore, superconducting magnets can be built into the tight space available with a sound mechanical structure.

The multiplication of 14 MeV D-T fusion neutrons via (n,2n), (n,3n), and fission reactions by /sup 238/U is well known and established. This study consistently evaluates the effectiveness of a depleted (tails) UO/sub 2/ multiplier on increasing the production of /sup 233/U and tritium in a thorium/lithium fusion--fission hybrid blanket. Nuclear performance is evaluated as a function of exposure and zone thickness.

The feasibility of conducting fusion blanket integral neutronics experiments at the Rotating Target Neutron Source-II (RTNS-II) accelerator facility and the Tokamak Fusion Test Reactor (TFTR) was investigated. RTNS-II recently became operational, and the TFTR is scheduled to begin D-T operations during 1983. The experiments would provide reaction rate data of direct importance to blanket design in environments (neutron spectra) close to those expected in actual blankets. Data of this kind are especially important for a hybrid blanket, where design depends upon a balance of breeding and power production requirements. The blanket also provides an essential part of the toroidal field (TF) coil shielding. Therefore, experimental verification of design model calculations is important before any commitment to a definitie design is made.

An ignition tokamak reactor design has been obtained which represents a starting point for the conceptual design of a 1000 MW/sub e/ commercial system. The design includes Nb/sub 3/Sn superconducting coils (TF, OH, and SF), water-cooled fissile blanket (e.g., uranium oxide), positive-ion based neutral beams with no direct energy recovery, and an ignited plasma with a = 0.9 m and an aspect ratio A = 4.0. The TF coil bore has a vertical bore of 7 m and a horizontal bore of 5 m both of which are a factor of two larger than the corresponding bore dimensions of the LCP (Large Coil Project) TF coil. The plasma is characterized as follows: stability factor q = 2.5, Z/sub eff/ approx. 1, poloidal beta ..beta../sub p/ less than or equal to A, a elongation delta in the range between 1.6 and 1.7. A number of potential operating conditions for the plasma and device have been identified for which the plasma beta ..beta.. lies within the range from 6.5% to 7.3%, and the plasma temperature has an average value between 11 keV and 12.5 keV. The design was obtained using the computer code COAST and represents a self-consistent sizing and costing result.

The purpose of this joint ORNL/Westinghouse Program is to develop a design concept for a tokamak reactor blanket system which satisfies engineering requirements for a utility environment. While previous blanket studies have focused primarily on performance issues (thermal, neutronic, and structural), this study has emphasized consideration of reliability, fabricability, and lifetime.

The design of the Nova Laser Facility for inertial confinement fusion experiments at Lawrence Livermore National Laboratory is presented from an engineering perspective. Emphasis is placed upon design-to-performance requirements as they impact the various subsystems that comprise this complex experimental facility.

Plasma size is an important parameter in wavelength-scaling experiments because it determines both the threshold and potential gain for a variety of laser-plasma instabilities. Most experiments to date have of necessity produced relatively small plasmas, due to laser energy and pulse-length limitations. We have discussed in detail three recent Livermore experiments which had large enough plasmas that some instability thresholds were exceeded or approached. Our evidence for Raman scatter, filamentation, and the two-plasmon decay instability needs to be confirmed in experiments which measure several instability signatures simultaneously, and which produce more quantitative information about the local density and temperature profiles than we have today.

Atomic processes dominate antiproton stopping in matter at nearly all energies of interest. They significantly influence or determine the antiproton annihilation rate at all energies around or below several MeV. This article reviews what is known about these atomic processes. For stopping above about 10 eV the processes are antiproton-electron collisions, effective at medium keV through high MeV energies, and elastic collisions with atoms and adiabatic ionization of atoms, effective from medium eV through low keB energies. For annihilation above about 10 eV is the enhancement of the antiproton annihilation rate due to the antiproton-nucleus coulomb attraction, effective around and below a few tens of MeV. At about 10 eV and below, the atomic rearrangement/annihilation process determines both the stopping and annihilation rates. Although a fair amount of theoretical and some experimental work relevant to these processes exist, there are a number of energy ranges and material types for which experimental data does not exist and for which the theoretical information is not as well grounded or as accurate as desired. Additional experimental and theoretical work is required for accurate prediction of antiproton stopping and annihilation for energies and material relevant to antiproton experimentation and application.

In order for computation to emerge spontaneously and become an important factor in the dynamics of a system, the material substrate must support the primitive functions required for computation: the transmission, storage, and modification of information. Under what conditions might we expect physical systems to support such computational primitives This paper presents research on Cellular Automata which suggests that the optimal conditions for the support of information transmission, storage, and modification, are achieved in the vicinity of a phase transition. We observe surprising similarities between the behaviors of computations and systems near phase-transitions, finding analogs of computational complexity classes and the Halting problem within the phenomenology of phase-transitions. We conclude that there is a fundamental connection between computation and phase-transitions, and discuss some of the implications for our understanding of nature if such a connection is borne out. 31 refs., 16 figs.

A generalized economic model was developed to predict the breakeven price of HDR generated electricity. Important parameters include: (1) resource quality--average geothermal gradient ({sup o}C/km) and well depth, (2) reservoir performance--effective productivity, flow impedance, and lifetime (thermal drawdown rate), (3) cost components--drilling, reservoir formation, and power plant costs and (4) economic factors--discount and interest rates, taxes, etc. Detailed cost correlations based on historical data and results of other studies are presented for drilling, stimulation, and power plant costs. Results of the generalized model are compared to the results of several published economic assessments. Critical parameters affecting economic viability are drilling costs and reservoir performance. For example, high gradient areas are attractive because shallower well depths and/or lower reservoir production rates are permissible. Under a reasonable set of assumptions regarding reservoir impedance, accessible rock volumes and surface areas, and mass flow rates (to limit thermal drawdown rates to about 10 C per year), predictions for HDR-produced electricity result in competitive breakeven prices in the range of 5 to 9 cents/kWh for resources having average gradients above 50 C/km. Lower gradient areas require improved reservoir performance and/or lower well drilling costs.

The comprehensive rehabilitation of the Lawrence Livermore National Laboratory Sanitary Sewer System centers around a Cured-in-Place Pipe project. Driven by regulatory requirements to eliminate the potential for exfiltration, a careful condition assessment of the existing infrastructure was conducted. Under programmatic constraints to maintain continuous operations, the INLINER USA cured-in-place pipe system was selected as the appropriate technology, and the project is currently under contract.

High-power density electronic components such as fast microprocessors and power semiconductors are often limited by inability to keep the device junctions below their max rated operating temperature. Present high power multichip module and single chip package designs use substrate materials such as Si nitride or copper tungsten with thermal conductivity in the range of 200 W/m{center_dot}K. We have developed a copper-diamond composite (Dymalloy) with a thermal conductivity of 420 W/m{center_dot}K, better than Cu, and an adjustable thermal expansion coefficient (TCE=5.5 ppM/C at 25 C), compatible with Si and GaAs. Because of the matched TCE, it is possible to use low thermal resistance hard die attach methods. The mechanical properties of the composite also make it attractive as an electronic component substrate material.

An experimental program has been designed to examine the chemical durability of glass compositions derived from the vitrification of simulated wastewater treatment sludges. These sludges represent the majority of low-level mixed wastes currently in need of treatment by the US DOE. The major oxides in these model glasses included SiO{sub 2}, Al{sub 2}O{sub 3}, B{sub 2}O{sub 3}, Na{sub 2}O, CaO and Fe{sub 2}O{sub 3}. In addition, three minor oxides, BaO, NiO, and PbO, were added as hazardous metals. The major oxides were each varied at two levels resulting in 32 experimental glasses. The chemical durability was measured by the 7-Day Product Consistency Test (PCT). The normalized sodium release rates (NRR{sub Na}) of these glasses ranged from 0.01 to 4.99 g/m{sup 2}. The molar ratio of the glass-former to glass-modifier (F/M) was found to have the greatest effect on PCT durability. Glass-formers included SiO{sub 2}, Al{sub 2}O{sub 3}, and B{sub 2}O{sub 3}, while Na{sub 2}O, CaO, BaO, NiO, and PbO were glass-modifiers. As this ratio increased from 0.75 to 2.0, NRR{sub Na} was found to decrease between one and two orders of magnitude. Another important effect on NRR{sub Na} was the Na{sub 2}O/CaO ratio. As this ratio increased from 0.5 to …

The surface figure of the individual mirrors of a two mirror, four reflection, ring field imaging system has been measured after each phase of the construction process: substrate fabrication, coating and potting. Contributions to the final system wavefront error and performance of the system in terms of the modulation transfer function and initial imaging tests are discussed.

Perhaps the most common approximation in engineering is that, relative to its neighbors, a system component is structurally rigid. This paper presents a development of the rigid assumption for use in nonlinear, implicit finite element codes. In this method, computational economy is gained by condensing the size of the associated linear system of equations, eliminating the processing of rigid elements, and reducing the overall nonlinearity of the problem.

The scalar wave theory is used to evaluate the expected diffraction patterns from a circular aperture. The standard far-field Kirchhoff approximation is compared to the exact result expressed in terms of oblate spheroidal harmonics. Deviations from an expanding spherical wave are calculated for circular aperture radius and the incident beam wavelength using suggested values for a recently proposed point diffractin interferometer. The Kirchhoff approximation is increasingly reliable in the far-field limit as the aperture radius is increased, although significant errors in amplitude and phase persist.

A uranium plume emanating from the U.S. Department of Energy`s Fernald Environmental Management Project (FEMP) in Fernald, Ohio had migrated off site and the leading edge of the plume had already mixed with an organic and inorganic plume emanating from two industries south of the FEMP. A method was needed to prevent the further southern migration of the plume, minimize any impacts to the geometry, concentrations, distribution or flow patterns of the organic and inorganic plumes emanating from the off-site industries, while meeting the ultimate cleanup goals for the FEMP. This paper discusses the use of a hydraulic barrier created to meet these goals by pumping a five well recovery system and the problems associated with the disposition of over 2 million gallons per day of water with low concentrations of uranium.

DOE`s contract reform initiatives at Fernald and the performance-based system DOE is now using to evaluate FERMCO are key elements to the current and future success of DOE and FERMCO at Fernald. Final cleanup of the Fernald site is planned for completion by 2005 per an accelerated 10-year remediation plan which has been approved by DOE and endorsed by the US EPA, Ohio EPA, and the Fernald Citizens Task Force. Required funding of approximately $276 million plus inflation annually for 10 years to accomplish final cleanup is now being considered by US Congress. Contract reform initiatives and modified performance measurement systems, along with best business practices, are clearing the path for the expedited cleanup of Fernald.

One option for control and disposal of surplus fissile materials is the Glass Material Oxidation and Dissolution System (GMODS), a process developed at ORNL for directly converting Pu-bearing material into a durable high-quality glass waste form. This paper presents a preliminary assessment of the GMODS process flowsheet using FLOW, a chemical process simulator. The simulation showed that the glass chemistry postulated ion the models has acceptable levels of risks.

ORNL has accumulated considerable quantitites of mixed wastes, many containing hazardous and radioactive components. Finding a suitable technique for treating mixed wastes is a challenging task. The Federal Facilities Compliance Act requires ODE to provide on-site treatment plans. A method of analysis was needed for quick, easy trade-off studies and alternatives evaluations. Evaluation of ORO management of mixed waste indicated that a systems analysis, including development of automated analysis tools and integrated models, was required. Integrated systems approach was needed because of the complexity. Risk, cost, performance, and uncertainty were considered. Resuts produced in these studies may be refined as more nearly accurate information is obtained about uncertanties in some treatment alternative.

Many safety systems, such as those in nuclear power plants, are systems for which the consequences of failure can be severe or catastrophic. These systems must be developed, implemented, and maintained in ways that provide assurance that catastrophic consequences will be prevented. This paper discusses various aspects of the question of using commercially available software in these systems. Risk, grading, and system assessment are discussed, and relevant standards are summarized. Recommendations for addressing key issues are given.

This paper presents a summary of results from the Single-Heater Test (SHT) at Yucca Mountain, Nevada. In the SHT, a horizontal, 5-m-long, line-heat source was used to heat a rock pillar for nine months. Moisture movement was monitored during and after heating using electrical-resistance tomography (ERT) and neutron-logging techniques. Results indicate drying in regions of the rock where temperature reached 60°C and above. The drying zone is asymmetric and is not centered on the heater, but has lobes extending above and to the sides of the heater. Predicted temperatures agreed well with observations. A cold- trap effect was predicted, in the heater borehole, that efficiently transfers heat along the heater borehole to the excavation wall. A simple thermomechanical analysis of the SHT shows that shear zones predicted for vertical fractures coincide with regions of increased moisture content derived from ERT measurements.

A Nanoindenter^TM equipped with a Vickers indenter was used to measure fracture toughness of Multilayer Capacitors (MLCs) and BaTiO₃ blanks. Strength of blanks of 6.3 x 4.7 x 1.1 mm³ was measured by performing three-point flexure using a 4 mm support span. The size of the strength limiting pores in the flexure tests was compared to pore sizes measured on polished MLC cross sections, and it was found that much larger pores were present in the 3-point flexure specimens. Strength distributions for the MLCs were generated using the measured fracture toughness values, assuming the measured pores or second phase inclusions were strength limiting.