A model for interfacial cohesion is developed which describes the loss in the strength of an interface due to the segregation and adsorption of impurities on it. Distinctions are made between interface separations that occur too rapidly for any significant redistribution of adsorbing matter to take place and separations that are slow enough to allow full adsorption equilibrium. Expressions for the total work of complete decohesion are presented for both cases. The results are applied to well-known model adsorption isotherms and some experimental data for grain boundary adsorption of phosphorus in iron is analyzed with respect to the losses in intergranular cohesion.

Evaluation of the application of heavy ion accelerators to ignite d-t pellets in a thermonuclear reactor is discussed. Accelerator design requirements considered include transport-limited current, beam injection conditions, and pulse bunching and focusing characteristics. The desirability of resonant and non-resonant accelerating structures is comparatively examined. The required power system switch tubes are discussed. It is concluded that heavy ion accelerators could offer a promising solution to the pellet-igniter problem. The advantages pointed out for this approach include electric efficiency greater than 10 percent, the possibility of high repetition rates (1 to 10 Hz), and a mature technological base. (RME)

The objective of using the probability table method (PTM) was to use a continuous-energy Monte Carlo code in which the cross sections are given as multigroup constants and yet to account for self-shielding within each group. In order to achieve this objective, the PTM was extended to deterministic methods. The ALICE Monte Carle Neutron Transport Code uses the PTM for all 175 energy groups which span the energy range from thermal to 20 MeV. The TART, ALICE, and MCN codes were used to determine the critical radius of a sphere of UH/sub 3/, where the U/sup 235/ enrichment varied from 20 to 100%. The PTM was used to calculate the transmission through a 30 cm iron plate. The source was normal to the slab and distributed as 1.0/E from 20.0 MeV to 1 keV. For the problems investigated the ALICE code can calculate both shielding and criticality problems as accurately as the pointwise code MCN. 1 figure, 1 table. (RWR)

In order to demonstrate the practicality of the multi-band method (Cullen, Nucl. Sc. Eng., 55, 387 (1974)) as applied to all energy ranges, it is demonstrated that intermediate resonance effects may be included; usually only two or three, and at most four, bands are required in any cross section probability table; and a low-order rational approximation is an excellent means of defining Bonderenko sigma/sub 0/ self-shielded cross sections. 1 table.

The use of basic physical and geometric principles, coupled with current laser technology, seems likely to extend experimental hyperbaric physics investigations from the megabar region into the portions of parameter space in which the ideal (degenerate) Fermi gas approximation is valid for even the highest Z materials. Implosions and speed-multiplying rectilinear stacks of flat plates seem particularly apt techniques for the near-term, transient attainment of pressure of 10/sup 9/ atmospheres in the laboratory, and laser-energized pulsed x-ray ''cameras'' appear suitable for analyzing the basic properties of matter under such conditions.

The design of the prototype neutral beam injection system for TFTR is nearing completion at the Lawrence Livermore Laboratory. This paper describes some of the features of the facility at the Lawrence Berkeley Laboratory where this prototype will be assembled and tested.

Recently developed models are employed to describe the interaction of a high-current REB (relativistic electron beam) with planar gold foils in the presence of macroscopic electromagnetic fields. It is shown that, under certain conditions, azimuthal magnetic fields which either penetrate into the foil and/or exist on the transmission side of the foil can significantly enhance the specific power deposited in the foil over that which would be deposited for diode fields alone. Similar field effects suggest methods for improving the external conversion efficiencies, softening the spectra and focussing the source intensities of flash x-ray facilities. Finally, preliminary results are shown from a new trajectory-field model for self-consistent REB transport.

Using clonal derivatives of the Chinese hamster M3-1 cell line, we demonstrate the potential of flow systems to karyotype homogeneous aberrations (aberrations which are identical and present in every cell) and to detect heterogeneous aberrations (aberrations which occur randomly in a population and are not identical in every cell). Flow cytometry (FCM) of ethidium bromide stained isolated chromosomes from clone 650A of the M3-1 cells distinguishes nine chromosome types from the fourteen present in the actual karyotype. X-irradiation of this parent 650A clone produced two sub-clones with an altered flow karyotype, that is, their FCM distributions were characterized by the addition of new peaks and alterations in area under existing peaks. From the relative DNA content and area for each peak, as determined by computer analysis, we predicted that each clone had undergone a reciprocal translocation involving chromosomes from two peaks. This prediction was confirmed by Giemsa-banding the metaphase cells. Heterogeneous aberrations are reflected in the flow karyotype as an increase in background, that is, an increase in area underlying the chromosome peaks. This increase is dose dependent but, as yet, the sample variability has been too large for quantitative analysis. Flow sorting of the valleys between chromosome peaks produces …

The Fort St. Vrain High Temperature Gas Cooled Reactor core performance has been evaluated during the startup testing phase of the reactor operation. The reactor is graphite moderated, helium cooled, and uses coated particle fuel and on-line flow control to each of the 37 refueling regions. Principal objectives of startup testing were to determine: core and control system reactivity, radial power distribution, flow control capability, and initial fission product release. Information from the core demonstrates that Technical Specifications are being met, performance of the core and fuel is as expected, flow and reactivity control are predictable and simple for the operator to carry out.

The plasma focus, an accidentally discovered natural phenomenon, provides a pulsed power source of 10/sup 12/-10/sup 13/ watts in a variety of forms: electron bursts, ion bursts, and the stagnation and direct field heating of the snowplow. High density fusion work being conducted at Livermore with a plasma focus with maximum bank energy of 500 kJ at 40 kV is described. The primary purpose of the project is to employ the plasma focus as a pulsed power source to explore various fusion microexplosion concepts. The first exotic fuel experiments have been carried out at this facility by operating the focus on D/sub 2/+He/sup 3/ at 120 kJ and 27 kV.

The half-life of /sup 239/Pu was measured by determining the ingrowth of /sup 235/U during a known time by isotope dilution mass spectrometry techniques.

Radioactive waste is encountered at every step of the LWR fuel cycle, and health physics is needed in the management of these wastes. Environmental surveillance will be needed. Health physics analysis supports the program to put radioactive waste in deep geologic isolation. The role of the health physicist in public interaction and communications is discussed. (DLC)

A program for simple data analysis and report design is described. The design emphasizes flexibility, ease of use, and rapid interactive response. These considerations are discussed in relation to the choices that may be made in the analysis and display design process. The analysis may be directed and monitored at several points, data selection and calibration, binning, choice of data scaling, choice of graphic variable, and scaling of the graphic variable. Table rows and columns can be re-organized by operators such as ranking, sequencing, and grouping, and re-computed from arithmetic combinations of existing rows and columns. Where the raw data represent different cases scored over the same attributes, profile tables can be computed in a systematic fashion. Interactive report design is supported by a variety of page layout and chart annotation directives, which can be used to embellish and adjust the default line, bar, and pie charts. The program can be used interactively as well as driven from a prepared script, and uses a device independent graphic system. Although intended to be used primarily with a graphics terminal, at least half the actual use has been conventional report generation on both alphanumeric and graphic terminals. 1 fig., 1 table.

The spectral density, S/sub v/(f), of the voltage noise across 1-D current-biased tin films has been measured at the superconducting transition. Each film was freely suspended between two thermal clamps a distance L apart in a vacuum can. A thin layer of lead was evaporated on the outer portion of the films to leave an uncoated middle region of length l. S/sub v/(f) was flat at frequencies below f/sub L/ approximately D/L/sup 2/, where D is the thermal diffusivity. At frequencies between f/sub L/ and f/sub l/ approximately (L/l)/sup 2/f/sub L/ the slope was typically -0.8, while at frequencies above f/sub l/ the slope was somewhat less steep than -1.5. The shape and magnitude of S/sub v/(f) were in good agreement with an equilibrium temperature fluctuation model in which the temperature fluctuations are spatially uncorrelated. Measurements of the autocorrelation function also strongly supported this model. These results are in contrast with those obtained for normal films and films at the superconducting transition supported by substrates, for which a model was required with spatially correlated fluctuations. It is concluded that the 1/f noise for films on substrates is mediated by an interaction between the substrate and the film.

Fluid bed densities and levels are usually obtained from measurement of differential pressures between taps with a known vertical separation. Historically, this measurement has been difficult in high pressure coal gasification processes primarily due to plugging of the pressure taps and process instrument tubing. Likewise, the achievement of accurate and reliable pressure and differential pressure recordings is affected by similar circumstances. These typical problems were experienced at the SYNTHANE Pilot Plant at Bruceton which is operated for the U.S. Energy Research and Development Administration by the C.E. Lummus Company. Major changes were required in instrument location and selection, piping configuration, and methods of purging. Consistent and accurate data is now obtained. Recommendations for the installation and operation of such instruments are given.

The main objective of the tests described was to provide experimental data in order to verify the analytical models used to develop HTGR core design loads. Most of the testing was performed on a one-fifth scale full array core model subjected to uniaxial horizontal excitation. The tests initially focused on evaluating the overall core frequency response, core damping, fuel element collision forces and displacements, and in particular, the lateral support response as a function of the excitation frequency and g-level. Following this series of tests, a second test program was executed on the model with emphasis placed on obtaining fuel element dowel forces and rocking angles, as well as possible element uplift. In addition, new tests were included to re-evaluate fuel element collision forces and overall core damping which were not satisfactorily obtained earlier. Several test results are included to illustrate application of the new instrumentation. Finally, a comprehensive error analysis of the test system is presented which provides estimates of the various error sources and total error in the data.

The property requirements for breeder reactor fuel cladding materials are extremely stringent. Alloys with low sodium corrosion rates are required to avoid loss of strength from wall thinning at reactor operating temperatures. Data obtained on the following alloys are described: A-286, Inconel 706, Nimonic PE16, AISI 316, M-813 (sintered), Inconel 718, AISI 310, and Alloy 330. Tests were carried out at 700/sup 0/C for 2000 hours at a sodium velocity of 6 m/s and an oxygen content in sodium of 1 ppM. Corrosion rates and major elements depleted are tabulated. It is concluded that A-286, Inconel 706, and Nimonic PE16 are highly promising commercial alloys for cladding purposes on the basis of corrosion resistance. 5 figures, 1 table. (RWR)

An air sampling system was developed that merged the useful properties of solid adsorbers, vacuum cleaner air movers, and Civil Defense GM survey meters. The system can be used to monitor the environmental levels of /sup 131/I produced by release from containment accidents in nuclear power reactors.

A critical review of the thermal non-equilibrium phase change models applicable to the water reactor safety calculations is presented. Four specific areas are discussed: (1) rapid depressurization (flashing), (2) post-dryout heat transfer, (3) direct contact condensation, and (4) sub-cooled boiling. The models have been judged from a mechanistic viewpoint, and the areas where further work is needed have been pointed out. It is suggested that when a phase change occurs due to a difference in the bulk fluid temperatures, the non-equilibrium phase change process can be viewed as a linear, non-homogeneous thermal relaxation phenomenon. Direct measurements of the actual phase change rates and the interfacial area densities are emphasized. Finally, a recommendation for the volumetric vapor generation rates applicable to the above four specific areas is given.

The emulsion technique is being used to examine the angular and momentum distribution of fragments emitted from nonperipheral collisions between emulsion nuclei (AgBr) and heavy-ion projectiles /sup 4/He, /sup 16/O, and /sup 40/Ar in the range of energies 0.2 to 2.1 GeV/A. Selection criteria, scanning and measuring, measurements, and analytic procedure are addressed. Prong number distributions, range and angular distributions are shown. The following conclusions were drawn: there is no unique particle-emitting system; prong distributions dN/dtheta are broad and Maxwellian-like, with maxima that shift toward smaller angles as the fragment energy increases, and as the beam energy decreases; no statistically significant structure attributed to well-defined collective phenomena is observed; there is no evidence that the angular distribution for low-energy fragments depends on the impact parameters of the collision between heavy ions at 2.1 GeV/A; at 2.1 GeV/A the number of fragments per event emitted in the backward hemisphere is insensitive to projectile mass. 6 figures, 3 tables. (RWR)

The prime objective of the Peach Bottom End-of-Life Program was to validate specific HTGR design codes and predictions by comparison of actual and predicted physics, thermal, fission product, and materials behavior in Peach Bottom. Three consecutive phases of the program provide input to the HTGR design methods verifications: (1) Nondestructive fuel and circuit gamma scanning; (2) removal of steam generator and primary circuit components; and (3) Laboratory examinations of removed components. Component removal site work commenced with establishment of restricted access areas and installation of controlled atmosphere tents to retain relative humidity at <30%. A mock-up room was established to test and develop the tooling and to train operators under simulated working conditions. Primary circuit ducting samples were removed by trepanning, and steam generator access was achieved by a combination of arc gouging and grinding. Tubing samples were removed using internal cutters and external grinding. Throughout the component removal phase, strict health physics, safety, and quality assurance programs were implemented. A total of 148 samples of primary circuit ducting and steam generator tubing were removed with no significant health physics or safety incidents. Additionally, component removal served to provide access fordetermination of cesium plateout distribution by gamma scanning inside the …

The proceedings of the Materials Sciences Workshop on Phase Transformations, Stability, and Materials Interactions are divided into sections according to the following topics: (I) workshop scope and priorities; (II) study group reports--ERDA mission needs; (III) study group reports--technical area research priorities. (SDF)

The objective of this paper is to summarize measured resuspension concentrations and to consider the implications of these results. In these experiments, airborne concentrations were measured as functions of wind speed, airborne particle size, wind direction, and the collected-plutonium and other nuclides per gram of airborne soil. Airborne radionuclides were normalized by the total amount of airborne solids to relate concentration per gram of airborne solid to concentration per gram of radionuclide on the ground.

Separate abstracts were prepared for 30 papers presented.