The Savannah River Site has generated 77 million gallons of high level radioactive waste since the early 1950`s. By 1987, evaporation had reduced the concentration of the waste inventory to 35 million gallons. Currently, the wastes reside in large underground tanks as a soluble fraction stored, crystallized salts, and an insoluble fraction, sludge, which consists of hydrated transition metal oxides. The bulk of the radionuclides, 67 percent, are in the sludge while the crystallized salts and supernate are composed of the nitrates, nitrites, sulfates and hydroxides of sodium, potassium, and cesium. The principal radionuclide in the soluble waste is {sup 137}Cs with traces of {sup 90}Sr. The transformation of the high level wastes into a borosilicate glass suitable for permanent disposal is the goal of the Defense Waste Processing Facility (DWPF). To minimize the volume of glass produced, the soluble fraction of the waste is treated with sodium tetraphenylborate and sodium titanate in the waste tanks to precipitate the radioactive cesium ion and absorb the radioactive strontium ion. The precipitate is washed in the waste tanks and is then pumped to the DWPF. The precipitate, as received, is incompatible with the vitrification process because of the high aromatic carbon content …

Catalytic reforming of low octane gasoline is carried out on dual function catalysts, e.g. Pt/alumina, Pt-Re/alumina, Pt-Sn/alumina. Carboxylates are a constituent of coke on alumina; Re lowers this. 3 wt% Sn lowers both carboxylate and coke by 40% compared to alumina. 3% loadings of both Sn and Pt showed a strong synergistic effect: total coke is increased by 300% and carboxylate production is doubled. At 3% loadings of both metals, the ability of Pt to chemisorb CO is decreased, which parallels the excess coke. At 0.3%, both effects are not detectable. In order to understand the effects of second metals added with Pt on carboxylate production, a study of the mechanism of the production of carbon-oxygen species under reducing conditions of coke deposition is needed.

A brief summary is presented of the current status of jet studies in hadron-hadron collisions. The primary focus is on those issues that would benefit from comparisons of jet samples obtained from hadron-hadron collisions, from e{sup +}e{sup {minus}} annihilation events at LEP and from deep inelastic collisions at HERA. The important point is that, to perform this comparison properly, the jet various samples must be obtained using the same jet definition.

This paper describes in the needs and requirements to properly and efficiently model fission product transport on full scope reactor simulators. Current LWR simulators can be easily adapted to model severe accident phenomena and the transport of radionuclides. Once adapted these simulators can be used as a training tool during operator training exercises for training on severe accident guidelines, for training on containment venting procedures, or as training tool during site wide emergency training exercises.

This report discusses a spill of approximately 20 gallons of D2O (moderator) which occurred on February 7, 1990, at 0008 hours. The spill occurred while construction was removing process water lines from the 5B heat exchanger at a location referred to as a Rams Horn to allow the heat exchanger to be realigned. The heat exchangers in the other systems (loops) had been successfully disconnected (lines broken) during the previous two months and had been realigned without incident under the control of job plans similar to the System 5 job plan. Construction personnel reacted positively at the time the spill and successfully rebolted and tightened the leaking flanges on 5B and later on the 5A heat exchangers. This initial reaction stopped the leak and prevented a more severe incident. The spill incident resulted in a Site Alert declaration by the Shift Manager at 0220 hours when the Stack Tritium Monitor indicated a tritium release which exceeded the limits specified. After the event it was determined that a Temporary Procedure Change (TPC) to this DPSOL, had been approved and issued in April 1989. Had this TPC been available to the Shift Manager, the alert would not have been declared. Although the …

Work is described briefly, which was carried out on development of techniques to grow metal-semiconductor superlattices (artificially layered materials) and on the copper oxide based susperconductors (naturally layered materials). The current growth technique utilized is metalorganic chemical vapor deposition (MOCVD). CdTe, PbTe, La, LaTe, and Bi{sub 2}Te{sub 3} were deposited, mostly on GaAs. Several YBa{sub 2}Cu{sub 3}O{sub 7} compounds were obtained with possible superconductivity at temperatures up to 550 K (1 part in 10{sup 4}). YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} and Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub y} thin films were deposited by MOCVD on common substrates such as glass.

Signal validation and process monitoring problems in many cases require the prediction of one or more process variables in a system. The feasibility of using neural networks to characterize one variable as a function of other related variables is studied. The Backpropagation Network (BPN) is used to develop ``models`` of signals from both a commercial power plant and the EBR-II. Several innovations are made in the algorithm, the most significant of which is the progressive adjustment of the sigmoidal threshold function and weight updating terms, thus leading to the designation ``Adaptive`` Backpropagation Neural Network. The estimation of system variables is performed traditionally using either physical models or empirical models. The prediction of system variables is important in control systems for validating instrumentation outputs and for process monitoring. The model-based prediction assumes a fixed structure for characterizing steady-state or dynamic relationship among process variables. The applications to large and complex systems require more time in order to get an accurate model. Since our goal is to relate signals in a subsystem of a plant, such a relationship can be developed by using neural network ``models`` which provide results faster than model-based techniques. Both steady-state and transient behavior can be incorporated into …

This paper presents the implementation of scientific programs on a decoupled data-driven architecture with vectors and macro actors. This hybrid multiprocessor combines the dynamic data-flow principles of execution with the control-flow of the von Neumann model of execution. The two major ideas utilized by the decoupled model are: Vector and macro actors with variable resolution, and asynchronous execution of graph and computation operations. The compiler generates graphs with various-sized actors in order to match the characteristics of the computation. For instance, vector actors are proposed for many aspects of scientific computing while lower resolution (complier-generated collection of scalar actors) or higher resolution (scalar actors) is used for unvectorizable programs. A block-scheduling technique for extracting more parallelism from sequential constructs is incorporated in the decoupled architecture. In addition a graph-level priority-scheduling mechanism is implemented that improves resource utilization and yields higher performance. A graph unit executes all graph operations and a computation unit executes all computation operations. The independence of the two main units of the machine allows the efficient pipelined execution of macro actors with diverse granularity characteristics.

This paper presents a hybrid multiprocessor architecture that combines the advantages of the dynamic data-flow principles of execution with those of the control-flow model of execution. Two major design ideas are utilized by the proposed model: asynchronous execution of graph and computation operations, and variable- resolution actors. The independence of the two main unites of the machine allows an efficient implementation of functional/data-flow principles with conventional, mature technology. The compiler generates graphs with variable-sized actors in order to match the characteristics of the application to the target machine. For instance, vector actors are proposed for many aspects of scientific computing, while lower resolution (Compound Macro Actors) or conversely higher resolution (atomic instruction actors) is used for unvectorizable programs.

We have implemented a 2D electrostastic plasma particle in cell (PIC) simulation code on the Caltech/JPL Mark IIIfp Hypercube. The code simulates plasma effects by evolving in time the trajectories of thousands to millions of charged particles subject to their self-consistent fields. Each particle`s position and velocity is advanced in time using a leap frog method for integrating Newton`s equations of motion in electric and magnetic fields. The electric field due to these moving charged particles is calculated on a spatial grid at each time by solving Poisson`s equation in Fourier space. These two tasks represent the largest part of the computation. To obtain efficient operation on a distributed memory parallel computer, we are using the General Concurrent PIC (GCPIC) algorithm previously developed for a 1D parallel PIC code.

The ``Weatherization Residential Assistance Partnership,`` or WRAP program, is a fuel-blind conservation program designed to assist Northeast Utilities` low-income customers to use energy safely and efficiently. Innovative with respect to its collaborative approach and its focus on utilizing and strengthening the existing low-income weatherization service delivery network, the WRAP program offers an interesting model to other utilities which traditionally have relied on for-profit energy service contractors and highly centralized program implementation structures. This evaluation of the WRAP program is designed to: (1) Review the continuing relevance of the demand-side management option screening methodology for determining program configuration for services delivery, including rural populations; (2) locate and analyze recent additions to the energy conservation literature, data and information that bear on design of the WRAP program; and (3) through interviews assess participant impressions of the collaborative process used to plan, develop and implement the WRAP process.

The neutron transport equation is solved by a hybrid method that iteratively couples regions where deterministic (S{sub N}) and stochastic (Monte Carlo) methods are applied. Unlike previous hybrid methods, the Monte Carlo and S{sub N} regions are fully coupled in the sense that no assumption is made about geometrical separation or decoupling. The hybrid method provides a new means of solving problems involving both optically thick and optically thin regions that neither Monte Carlo nor S{sub N} is well suited for by themselves. The fully coupled Monte Carlo/S{sub N} technique consists of defining spatial and/or energy regions of a problem in which either a Monte Carlo calculation or an S{sub N} calculation is to be performed. The Monte Carlo region may comprise the entire spatial region for selected energy groups, or may consist of a rectangular area that is either completely or partially embedded in an arbitrary S{sub N} region. The Monte Carlo and S{sub N} regions are then connected through the common angular boundary fluxes, which are determined iteratively using the response matrix technique, and volumetric sources. The hybrid method has been implemented in the S{sub N} code TWODANT by adding special-purpose Monte Carlo subroutines to calculate the response …

This report discusses the following topics on electron beam guns: Precharger Modification; Installation of Charge vs. Radius Apparatus; High Concentration Aerosol Generation; and Data Acquisition and Analysis System.

Electrostatic collection of a high resistivity aerosol using the Electron Beam Precipitator (EBP) collecting section was demonstrated during this reporting period (Quarter Five). Collection efficiency experiments were designed to confirm and extend some of the work performed under the previous contract. The reason for doing this was to attempt to improve upon the collection efficiency of the precipitator alone when testing with a very high resistivity, moderate-to-high concentration dust load. From the collector shakedown runs, a set of suitable operational parameters were determined for the downstream electrostatic collecting sections of the Electron Beam Precipitator wind tunnel. These parameters, along with those for the MINACC electron beam, will generally be held constant while the numerous precharging parameters are varied to produce an optimum particle charge. The electrostatic collector experiments were part of a larger, comprehensive investigation on electron beam precharging of high resistivity aerosol particles performed during the period covered by Quarters Five, Six, and Seven. This body of work used the same experimental apparatus and procedures and the experimental run period lasted nearly continuously for six months. A summary of the Quarter Five work is presented in the following paragraphs. Section II-A of TPR 5 contains a report on the …

The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer`s rated loads. 3 refs.

The objective of this program is to investigate the direct conversion of light gaseous hydrocarbons, such as those produced during Fischer-Tropsch synthesis or as a product of gasification, to liquid transportation fuels via a partial oxidation process. The process will be tested in an existing pilot plant to obtain credible mass balances. Specific objectives to be met include determination of optimal process conditions, investigation of various processing options (e.g. feed injection, product quench, and recycle systems), and evaluation of the various options will be performed as experimental data become available.

The objective of this program is to investigate the direct conversion of light gaseous hydrocarbons, such as those produced during Fischer-Tropsch synthesis or as a product of gasification, to liquid transportation fuels via a partial oxidation process. The process will be tested in an existing pilot plant to obtain credible mass balances. Specific objectives to be met include determination of optimal process conditions, investigation of various processing options (e.g. feed injection, product quench, and recycle systems), and evaluation of an enhanced yield thermal/catalytic system. Economic evaluation of the various options will be performed as experimental data become available.

This document describes passive decay-heat removal system for a water-cooled nuclear reactor which employs a closed heat transfer loop having heat-exchanging coils inside an open-topped, insulated evaporator located inside the reactor vessel, below its normal water level, in communication with a condenser located outside of containment and exposed to the atmosphere. The heat transfer loop is located such that the evaporator is in a position where, when the water level drops in the reactor, it will become exposed to steam. Vapor produced in the evaporator passes upward to the condenser above the normal water level. In operation, condensation in the condenser removes heat from the system, and the condensed liquid is returned to the evaporator. The system is disposed such that during normal reactor operations where the water level is at its usual position, very little heat will be removed from the system, but during emergency, low water level conditions, substantial amounts of decay heat will be removed.

Yucca Mountain, Nevada, has been proposed as the site of a high-level nuclear waste repository. The purpose of this paper is to outline aspects of the geology and tectonics of the area which bear on its suitability as a waste repository. The repository is to be excavated from a non-lithophysal zone within the lower part of the Paintbrush Tuff. Revised estimates of the thickness of this zone indicate that the lower, down-dip extremity of the planned repository could be raised by as much as 130 m, thus reducing the grade within the repository and increasing the distance to the water table below. We note that because of the closely spaced fracturing and low in-situ stresses within the repository block, lateral support of fractured rock is likely to be poor. 30 refs., 5 figs.

Despite its high nitrogen concentration levels relative to the parent coal samples, 7.2% vs. 1.4 - 2.0%, little volatile nitrogen evolution is observed until decomposition temperatures of 600{degree}C or greater are obtained. Due to the lack of decomposition via tar evolution and as contrasted to parent coals, no significant bound nitrogen is evolved with heavy hydrocarbons at particle temperatures less than 600{degree}C. Similar to ``virgin`` chars and tars formed during rapid devolatilization, the polyimide samples begin to evolve significant fractions of bound nitrogen as IR-active light gases at particle temperatures between 650 and 750{degree}C. Unlike coal samples, however, relatively large fractions of the light gases are observed to be ammonia. The IR-active, nitrogen-containing light gas evolution rapidly declines at polyimide char temperatures greater than 750{degree}C, again in contrast to observed behavior in virgin coal char samples. It is not certain if the nitrogen evolution kinetics changes from selectively forming ammonia and hydrogen cyanide to benzonitriles or free nitrogen at these temperatures. The light gas evolution pattern with decomposition temperature of polymide could contribute to our understanding of the low conversion efficiencies observed for bound nitrogen to NO{sub x} conversion in the char combustion phase of pfc combustion.

With the discovery of the electron superconductors, a new dimension was added to research in the field of high-temperature superconductivity. Studies of these materials should help elucidate the mechanism responsible for high-temperature superconductivity, as well as improve strategies for finding new superconductors. In this paper, we discuss the superconducting structural properties of Nd{sub 1.85}Ce{sub 0.15}(Cu{sub 1-y}Zn{sub y})O{sub 4} as a function of the Zn concentration y. Detailed comparisons with previous results of similar substitution studies in the single-CuO{sub 2}-layer hole superconductor La{sub 1.85}Sr{sub 0.15}CuO{sub 4} also are made. We have found that the non-magnetic element Zn has a detrimental effect on the T{prime}-phase electron superconductor, and that this effect is as strong as in the T-phase hole superconductor. Theoretical implications and the question of electron-hole symmetry are also discussed.

The project objectives are (1) to synthesize permselective ceramic membranes by chemical vapor deposition of SiO{sub 2} and other oxides within the walls of porous support tubes, (2) measure membrane permeability and thermal stability to various gases at 200--700{degrees}C and (3) develop a mathematical model for the chemical vapor deposition of the permselective oxide within the porous support tube.

Manual tank calibrations often have variabilities of both a random and systematic nature that often affect the quality of the data collected for determining accurate calibration equations. When performing the calibration run, data omissions and transcriptions often occur (forgetting to tare weigh the prover vessel or miswriting a displayed value). A computer can be used to minimize these errors associated with the logging of data. This paper describes a IBM compatible, portable computer based system, developed at the Savannah River Site (SRS), that was used to calibrate three tanks in the second quarter 1990. It received data directly from instrumentation such as Ruska differential pressure sensors and electronic balances, while prompting the technicians to perform the various steps in the calibration procedure. This automated system greatly improved the quality of data for calculating the calibration equation for each of these tanks over previous calibration runs.

Equipment progress include furnace construction and electron microprobe installation. The following studies are underway: phase equilibria along basalt-rhyolite mixing line (olivine crystallization from natural silicic andensites, distribution of Fe and Mg between olivine and liquid, dist. of Ca and Na between plagioclase and liquid), enthalpy-composition relations in magmas (bulk heat capacity of alkali basalt), density model for magma ascent and contamination, thermobarometry in igneous systems (olivine/plagioclase phenocryst growth in Quat. basalt), high-pressure phase equilibria of alkali basalt, basalt-quartz mixing experiments, phase equilibria of East African basalts, and granitic minerals in mafic magma. (DLC)