The modeling of the natural state of the Krafla system has yielded results that closely match all available field data, and agree with a conceptual model developed from geochemical observations. Furthermore, studies of the sensitivity of various parameters give valuable insight into the permeabilities of different reservoir zones, thermal conductivity of the caprock, rates and enthalpies of natural recharge and discharge, and various other important reservoir parameters. The model presented here is two-dimensional, and only considers a part of the old wellfield. In the future, we hope to develop a natural-state model for the entire Krafla system, taking into account the three-dimensional nature of fluid flows.

The general maintenance philosophy for replacement of modules is reviewed in this paper. This includes a discussion of the method for disassembly of the spent module in a hot bay area. An initial equipment requirements list is developed to support the maintenance approach.

An adiabatic field-cycle method has been used to study spin dynamics of RE ions in (Y/sub 1-x/RE/sub x/)Rh/sub 4/B/sub 4/. Longitudinal dipolar fluctuations of RE moments are found to be the main source of the nuclear spin-lattice relaxation time of /sup 11/B. The variation of T/sub 1/ in the superconducting state is attributed to the reduction of the electronic spin-relaxation time, tau/sub m/, which is mainly determined by the RKKY type interaction mediated by the conduction electrons. 3 figures.

A new method has been devised for focusing and imaging the radiation from sharp-line sources of x-rays and gamma-rays, which makes use of variable-metric diffraction crystals. A variable-metric diffraction crystal is one in which the spacings between the crystalline planes is varied as a function of position in the crystal by either the application of a thermal gradient or by changing the composition of a two component or multiple component crystal. This change in planar spacing changes the Bragg diffraction angle for monochromatic radiation as a function of position in the crystal and makes it possible to obtain focusing and in some cases imaging of a sharp-line point source or parallel beam source. This new approach to focusing x-rays and gamma-rays is used to design a number of gamma ray telescopes suitable for focusing the 511 keV annihilation radiation from the strong source of the center of our galaxy. The new designs are surprisingly efficient with approximately 20% of the radiation incident on the variable-metric diffraction crystals being focused on the image spot. Crystals of Ge, Ge + Si, Si, and quartz are used with mosaic widths of 10 arc sec. The size of the telescope can be scaled up …

This paper identifies and discusses some of the important consequences of nuclear power plant unavailability, and quantifies a number of technical measures of loss of benefits that result from regulatory actions such as licensing delays and mandated nuclear plant outages. The loss of benefits that accompany such regulatory actions include increased costs of systems generation, increased demand for nonnuclear and often scarce fuels, and reduced system reliability. This paper is based on a series of case studies, supplemented by sensitivity studies, on hypothetical nuclear plant shutdowns. These studies were developed by Argonne in cooperation with four electric utilities.

In the past decade, ion implantation has been shown to reduce oxide thicknesses up to tenfold in survey experiments on Ti, Zr, Ni, Cu, and Cr, and to enhance the long-term oxidation resistance of some high-temperature alloys. This review summarizes the major results of previous work. Important concepts are illustrated using recent experimental results obtained from a He-implanted Ni-1 at.% Pt alloy. Collectively, the results indicate that ion implantation has considerable potential for reducing oxidation, and as a research tool to investigate the mechanisms of thermal oxidation in metals.

This talk is intended as background material for many of the other talks treating the possible applications of GUTs to the very early universe. I start with a review of the present theoretical and phenomenological status of GUTs before going on to raise some new issues for their prospective cosmological applications which arise in supersymmetric (susy) GUTs. The first section is an update on conventional GUTs, which is followed by a reminder of some of the motivations for going supersymmetric. There then follows a simple primer on susy and a discussion of the structure and phenomenology of simple sysy GUTs. Finally we come to the cosmological issues, including problems arising from the degeneracy of susy minima, baryosynthesis and supersymmetric inflation, the possibility that gravity is an essential complication in constructing susy GUTs and discussing their cosmology, and the related question of what mass range is allowed for the gravitino. Several parts of this write-up contain new material which has emerged either during the Workshop or subsequently. They are included here for completeness and the convenience of the prospective reader. Wherever possible, these anachronisms will be flagged so as to keep straight the historical record.

Purpose of this statement is to introduce the subject of oxidation potential, E/sub h/, and to discuss its control in experiments. After the concept of E/sub h/ is reviewed, the range of oxidation potentials expected to be associated with a repository for high level nuclear waste will be addressed. Finally, three laboratory methods of controlling E/sub h/ will be described, along with some perspective that has been derived from experience given for each method.

A review is presented of recent experimental and theoretical progress in studies of the production of massive lepton pairs in hadronic collisions. I begin with the classical Drell-Yan annihilation model and its predictions. Subsequently, I discuss deviations from scaling, the status of the proofs of factorization in the parton model, higher-order terms in the perturbative QCD expansion, the discrepancy between measured and predicted yields (K factor), high-twist terms, soft gluon effects, transverse-momentum distributions, implications for weak vector boson (W/sup + -/ and Z/sup 0/) yields and production properties, nuclear A dependence effects, correlations of the lepton pair with hadrons in the final state, and angular distributions in the lepton-pair rest frame.

Interest in the physical and chemical properties of small metal clusters has recently stimulated the development of sources for the generation of molecular beams of metal clusters, since the collision-free environment of a beam has the advantage of permitting in-flight study of isolated species free of interference from surroundings. For example, spectroscopic studies utilizing tunable lasers may be performed in the molecular beam environment. The objectives of our research program are the elucidation of the physical and chemical properties of clusters of refractory metal atoms, in particular those of the catalytically active transition metals. For these purposes we have built and tested two sources suitable for generation of cluster beams of refractory metals, one for continuous beams and the other for pulsed beams.

The discussion covers quarks as we know them, the classification of ordinary mesons in terms of constituent quarks, hidden charm states and charmed mesons, bottom quarks, positronium as a model for quarti q, quantum chromodynamics and its foundation in experiment, the charmonium model, the mass of states, fine structure and hyperfine structure, classification, widths of states, rate and multipolarity of gamma transitions, questions about bottom, leptonic widths and the determination of Q/sub b/, the mass splitting of the n/sup 3/S/sub 1/ states, the center of gravity of the masses of the n/sup 3/P; states, n/sup 3/ P; fine structure and classification, branching ratios for upsilon' ..-->.. tau chi/sub 6j/ and the tau cascade reactions, hyperfine splitting, and top. (GHT)

The decommissioning of reactor-based neutron sources in the USA has led to the development of a new generation of neutron sources that employ high-energy accelerators. Among the accelerator-based neutron sources presently in operation, the highest-flux source is the Intense Pulsed Neutron Source (IPNS), a user facility at Argonne National Laboratory. Neutrons in this source are produced by the interaction of 400 to 500 MeV protons with either of two /sup 238/U target systems. In the Radiation Effects Facility (REF), the /sup 238/U target is surrounded by Pb for neutron generatjion and reflection. The REF has three separate irradiation thimbles. Two thimbles provide irradiation temperatures between that of liquid He and several hundred degrees centigrade. The third thimble operates at ambient temperature. The large irradiation volume, the neutron spectrum and flux, the ability to transfer samples without warm up, and the dedication of the facilities during the irradiation make this ideally suited for radiation damage studies on components for superconducting fusion magnets. Possible experiments for fusion magnet materials are discussed on cyclic irradiation and annealing of stabilizers in a high magnetic field, mechanical tests on organic insulation irradiated at 4 K, and superconductors measured in high fields after irradiation.

Heat transfer and fluid flow over circular tubes have wide applications in the design of heat exchangers and nuclear reactors. However, it is often difficult to accurately calculate the detailed velocity and temperature distributions of the flow because of the complex geometry involved in the analysis, and a lack of an appropriate coordinate system for the analysis. Boundary conditions on the surfaces of the tubes are often interpolated. This interpolation process introduces inaccuracy. To overcome this difficulty, the present study used the technique of the boundary-fitted coordinate system. In this technique, all the physical boundaries are transformed into constant coordinate lines in the transformed coordinates. Therefore, the boundary conditions can be specified on the grid points without interpolation.

Changes of nuclear shapes at high spin have been observed in several transitional nuclei, including /sup 153/ /sup 154/Dy and /sup 186/Hg. In the Dy isotopes a transition from collective to single-particle character appears at high spin suggesting a change from prolate to oblate shapes. In /sup 186/Hg, decoupled i/sub 13/2/ quasiparticle bands with prolate and oblate shapes may have been observed in two crossing bands. The present discussion focusses on the polarizing effect of high-j rotation-aligned particles on the soft cores of these nuclei. Studies of the decay of the compound nucleus /sup 156/Er, produced at the rather low excitation energy of 46 MeV in the reaction /sup 64/Ni + /sup 92/Zr, are also reported. Measurements of neutron spectra as a function of ..gamma..-sum energy and of the neutron multiplicity distribution have been performed. Comparison with the results of statistical model calculations suggests a suppression of neutron emission and it is speculated that this might be due to trapping in a superdeformed well.

The response of the Cerro Prieto geothermal field to different reinjection schemes is predicted using a two-dimensional vertical reservoir model with single- or two-phase flow. The advance of cold fronts and pressure changes in the system associated with the inection operations are computed, taking into consideration the geologic characteristics of the field. The effects of well location, depth, and rates of injection are analyzed. Results indicate that significant pressure maintenance effects may be realized in a carefully designed reinjection operation.

The design of the ISABELLE Palmer magnets is described. The performance of thirteen such magnets is reported. Average quench fields of 55 kG at 4.5/sup 0/K have been obtained with essentially no training. The magnets can be shown to be limited only by the short sample characteristics of the cable. Required field quality was achieved in the last four magnets.

This meeting was arranged jointly by MIT and BNL in order to illuminate progress in the synthesis and targeting of boron compounds and to evaluate and document progress in radiobiological and dosimetric aspects of neutron capture therapy. It is hoped that this meeting will facilitate transfer of information between groups working in these fields, and encourage synergistic collaboration.

A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchangers for liquid-metal services. For the shellside fluid, the conservation equations of mass, momentum, and energy for continuum fluids are modified using the concept of porosity, surface permeability and distributed resistance to account for the blockage effects due to the presence of heat-transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, the heat-transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phase on the shell side and may undergo phase-change on the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reactor (LMFBR) intermediate heat exchangers (IHX) and steam generators (SG).

Multi-state single-plant risk models are developed and the impacts of various failure and repair characteristics associated with safe shutdown and multiple accident conditions are analyzed. Comparisons of models are presented and recommendations are made for selecting a model. Fundamental recursive equations are then derived for the probabilistic characteristics of components in general. These equations are new results for multi-state components, allow replacement components to be new or old, and allow general failure and repair time distributions to be used. The equations are solved for the time dependent state probabilities and conditional and unconditional failure and repair rates.

Scaling criteria for a natural circulation loop under single-phase and two-phase flow conditions have been derived. For a single-phase case the continuity, integral momentum, and energy equations in one-dimensional area average forms have been used. From this, the geometrical similarity groups, friction number, Richardson number, characteristic time constant ratio, Biot number, and heat source number are obtained. The Biot number involves the heat-transfer coefficient which may cause some difficulties in simulating the turbulent-flow regime. For a two-phase-flow case, the similarity groups obtained from a perturbation analysis based on the one-dimensional drift-flux model have been used. The physical significance of the phase-change number, subcooling number, drift-flux number, friction number are discussed and conditions imposed by these groups are evaluated. In the two-phase-flow case, the critical heat flux is one of the most-important transients which should be simulated in a scale model. The above results are applied to the LOFT facility in case of a natural-circulation simulation.

Significant work has been performed on debris-bed dryout on beds of either uniformly sized particles or particles of a wide size range which are well mixed. This work has provided an understanding of the mechanisms of dryout and an empirical basis for containment analysis. However, the debris bed resulting from a HCDA would not consist of uniformly sized particles and for certain scenarios the bed could be stratified rather than well mixed. Tests have been conducted on the effect of particle size distribution on dryout and concluded that not only is the mean particle size an important parameter but also the standard deviation of the distribution and change in porosity. The D6 in-pile test at Sandia with a 114-mm deep stratified bed resulted in a reduced dryout heat flux compared to a uniformly mixed bed. Because of the many questions concerning the dryout behavior of stratified beds of wide size distribution out-of-pile experiments in which metal particles in water pools are inductively heated were initiated at Argonne.

The status of the theoretical and experimental study of higher twist contributions to the nucleon structure functions is reviewed. After noting the dangers of combining experiments with widely different <Q/sup 2/> and targets, emphasis is placed on those results coming from a single experiment. The values of ..lambda.., the twist-2 scale factor, and h/sub 4/, the coefficient of x/Q/sup 2/(1-x), are restricted by: ..lambda.. <0.44 GeV and -0.2 <h/sub 4/<0.5 GeV/sup 2/.

The influence of different helium-injection schedules on microstructure development Ni/sup +/ ion irradiated 316 SS at 625/sup 0/C is discussed. Injection schedules were chosen to (1) approximate the magnetic fusion reactor condition and (2) mimic the mixed-spectrum reactor condition. Dual-ion irradiation to 25 dpa produced strongly bimodal cavity size distributions in solution-annealed and solution-annealed and aged samples, whereas single-ion irradiation followed by dual-ion irradiation to the same dose produced a cavity size distribution with a substantial component of intermediate-size cavities. Dual-ion irradiation produced only very small cavities in 20% CW material, while single-ion followed by dual-ion irradiation produced some intermediate size cavities and greater swelling. 10 figures.

Intrinsic tracer impurity diffusion measurements in ceramic oxides have been primarily confined to CoO, NiO, and Fe/sub 3/O/sub 4/. Tracer impurity diffusion in these materials and TiO/sub 2/, together with measurements of the effect of impurities on tracer diffusion (Co in NiO and Cr in CoO), are reviewed and discussed in terms of impurity-defect interactions and mechanisms of diffusion. Divalent impurities in divalent solvents seem to have a weak interaction with vacancies whereas trivalent impurities in divalent solvents strongly influence the vacancy concentrations and significantly reduce solvent jump frequencies near a trivalent impurity. Impurities with small ionic radii diffuse more slowly with a larger activation energy than impurities with larger ionic radii for all systems considered in this review. Cobalt ions (a moderate size impurity) diffuse rapidly along the open channels parallel to the c-axis in TiO/sub 2/ whereas chromium ions (a smaller-sized impurity) do not. 60 references, 11 figures.