The radioactive waste glass melter used at Savannah River Site (SRS) is a liquid slurry feed joule-heated ceramic melter. The physical nature of a joule-heated meter is complex and involves interactions between electric, thermal, and flow fields. These interactions take place through strongly temperature-dependent glass properties, natural convection, advection, diffusion, and volumetrically distributed joule heating sources. The cold feed on top of heated glass distabilizes the flow field and develops unsteady asymmetric flow motions underneath. Thus waste glass modeling requires solving a full 3-D, unsteady, momentum, energy, and electric equation with temperature-dependent properties. Simulation of noble metal deposit process requires an additional mass diffusion equation that is coupled to the momentum equation through mass advection term. The objective of this paper is to identify critical issues anticipated in the Defense Waste Process Facility (DWPF) melter operation and address how these issues can be resolved with current state-of-the-art mathematical modeling techniques.

When grown in the absence of light, the det1 mutants of Arabidopsis thaliana develop characteristics of light-grown plants by morphological, cellular, and molecular criteria. Further, in light-grown plants, mutations in the DET1 gene affect cell-type-specific expression of light-regulated genes and the chloroplast developmental program. Here we show that the addition of exogenously added cytokinins (either 2-isopentenyl adenine, kinetin, or benzyladenine) to the growth medium of dark-germinated wild-type seedlings results in seedlings that resemble det1 mutants, instead of having the normal etiolated morphology. Like det1 mutants, these dark-grown seedlings now contain chloroplasts and have high levels of expression of genes that are normally ``light``-regulated. These results suggest an important role for cytokinins during greening of Arabidopsis, and may implicate cytokinin levels or an increased sensitivity to cytokinins as explanations for some of the observed phenotypes of det1 mutants.

The boundary perturbation method, suggested by Zhang and (independently) by Chatard-Moulin, Cooper, and their colleagues, is employed to the wakefield calculations for geometrical discontinuities in accelerators. Results are compared with that obtained from the mesh calculations using TBCI. When the perturbation is small and the geometry is suitable for TBCI, agreement is good. Discrepancies observed in other cases are also discussed.

The purpose of this project is to elucidate the way in which the synthesis of ethanol and related fermentation products are regulated in the facultative anaerobe Escherichia coli. We are also investigating the control of other genes required for anaerobic growth. We have isolated both structural and regulatory mutations affecting the expression of alcohol dehydrogenase, the enzyme responsible for the final step in alcohol synthesis. Some of these regulatory mutations also affect other anaerobically induced genes. The adh gene has been cloned and sequenced. The ADH protein is one of the largest highly expressed proteins in E. coli and requires approximately 2700bp of DNA for its coding sequence. We have also isolated mutations affecting the fermentative lactate dehydrogenase and have recently cloned the ldh gene. In consequence it is now possible to construct E. coli strains defective in the production of any one or more of their normal fermentation products (i.e. formate, acetate, lactate, ethanol and succinate). The factors affecting ratio of fermentation products are being investigated by in vivo NMR spectroscopy.

Lysimeters are large-scale, field experiments used at the Savannah River Site (SRS) to measure the effect of percolating rainfall on the release of contaminants from wasteforms. The saltstone lysimeters described are demonstrations of a disposal concept for a low-level radioactive waste resulting from the processing of high-level defense waste for vitrification. Results from the lysimeters confirm the efficacy of the slag formulation in retaining chromium and technetium. Lysimeter results were also useful in validating mathematical models used in predicting environmental effects of saltstone disposal in engineered vaults. 7 refs., 3 figs., 4 tabs.

The Savannah River Site has conducted a study to statistically quantify differences in metals concentrations as a function of sampling device and filter treatment. Twelve wells screened in unconsolidated coastal plain sediments were sampled for the study. All wells had histories of detectable toxic metals concentrations. Unfiltered and filtered (using 10 and 0.45 micron filters) samples were collected from all wells to evaluate the effects of filtering. To compare the effects of sampling device, the wells were sampled twice, once with a bladder pump and once with a centrifugal pump. An analysis of covariance (ANCOVA) method was used to assess the effects of sampling device and filtration on metals concentrations considering the variation in pH, conductivity, and turbidity among samples. This study demonstrates that when controlled sampling techniques are employed, differences in toxic metals concentrations between filtered and unfiltered samples are not statistically significant. However, variations in sampling devices yield samples with statistically different metals concentrations. The centrifugal pumps, which cause more agitation of the sample and the screened zone than bladder pumps, yield samples with statistically higher metals concentrations.

We have presented evidence that the functional thyroid follicles (follicular units, FU) which are formed in grafts of monodispersed rat thyroid cells, and hence the thyroid tumors which later develop in such grafts, are clonal in origin. Recent studies have been designed to investigate: whether cell number-dependent inhibition of promotion-progression is mediated by remote hormonal feed-back, local cell-cell interactions, or both; the cell population kinetics of the clonogen subpopulation during goitrogenesis and goiter involution; and the effect of prolonged exposure to high levels of TSH (thyrotropin) on the capacity of the clonogens to give rise to functional FU. The results indicate that local cell-cell interactions play an important role in the cell number-dependent suppression of neoplastic promotion-progression. They also show that if sufficient thyroid cells are grafted, the thyroid-pituitary axis can be reestablished in thyroidectomized rats fed normal diets. In such animals given iodine deficient diets, the FU that develop in the thyroid grafts shift their secretory pattern to increase the ratio of T3 (triiodothyronine) to T4 (thyroxine), and thus conserve the available iodine. Finally, the clonogenic subpopulation is conserved during both goitrogenesis and goiter involution. When they are transplanted to thyroidectomized recipients, clonogens from two types of goiters form …

A three-stage thin-film detector for the identification of heavy ion fragments was investigated in beam at HHIRF. An experiment on Eu-152 for the purposes of calibrating a four-crystal Germanium polarimeter was performed. The instrument was then used in an experiment to establish polarities for the low-lying transitions in {sup 82}Sr. The spectral fitting code ROBFIT was applied to the data analysis and shown to perform well on the extraction of weak peaks in high background situations.

High-level radioactive sludge at the Savannah River Site (SRS) will be processed at the Defense Waste Processing Facility (DWPF) into durable borosilicate glass wasteforms. The sludges are analyzed for elemental content before processing to ensure compatibility with the glass-making processes. Noble metal fission products in sludge, can under certain conditions, cause problems in the glass melter. Therefore, reliable noble metal determinations are important. The scheme used to measure noble metals in SRS sludges consists of dissolving sludge with hot aqua regia followed by determinations with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and ICP-Mass Spectroscopy (ICP-MS) techniques. ICP-MS is the preferred method for measuring trace levels of noble metals in SRS radioactive waste because of superior sensitivity. Analytical results are presented for the two major types of SRS sludge.

The Savannah River Site generates waste containing depleted, natural, and enriched uranium residue. The past and current practice for disposal of this waste at the Savannah River Site have been assessed using radionuclide pathway analysis to estimate environmental impact of closure alternatives for existing disposal sites, and to assist in the development of improved disposal facilities in the near future. This paper outlines the status of uranium waste management technology as currently practiced to maintain the environmental impact within an acceptable limit at the Savannah River Site, and indicates those steps being taken to improve future operations.

XANES and EXAFS measurements were made on a CuO/Al{sub 2}O{sub 3} sample which went through a complete reaction cycle with flue gases, followed by comparison with pure CuO. In the modeling studies, of the possible bridging type adsorption configurations for the SO{sub 2} molecule on CuO/Al{sub 2}O{sub 3}, the only one yielding SO{sub 2} adsorption of possible practical interest is that for the SO{sub 2} molecule bridging a Cu and an Al atom with the molecule bent away from the surface; the bonding energy is 1.66 eV.

XANES spectra are given for a number of model sulfur-containing compounds. The XANES and EXAFS spectra and structures of the inorganic standards (CuSO{sub 4}, FeS{sub 2}, FeS, CuS) are discussed. Calculations were made on SO{sub 2} adsorption on CuO/Al{sub 2}O{sub 3} surface; results show that the SO{sub 2} is adsorbed on the surface via O-Cu bonding, probably in the form of a ``bridge`` with the two oxygen atoms of SO{sub 2}sitting at two surface metal atoms. It is probably better to have low-temperature adsorption in reusable adsorbents because of the lower bonding energy of the O-Cu bonding. The possibility of adsorption at the edge or corner of the material is considered.

RHEED (reflection high energy electron diffraction) was carried out on Cu(110) at 153 to 973 K. Specular spot profiles show decreased scattering intensity around 550 K. RHEED patterns show disappearance of Kikuchi lines above 800 K. LEED indicate anharmonicities on Cu(110) surface at high temperatures. Results suggest that anharmonic effects precede onset of a rough surface at about 800 K. Three possible models were investigated for the clean surface for copper oxide dispersed on alumina; one was selected to use in going on to treat SO{sub 2} sorption. The Gauss-88 technique was used on Cray YMP to initiate cluster calculations for treating adsorption of the SO{sub 2} molecule. Of the possibilities for how SO{sub 2} adsorbs on CuO/Al{sub 2}O{sub 3} surface, sulfur-to-metal bonding was first considered, with the SO{sub 2} molecule on top of the Cu atom; this first configuration was found not to be energetically favorable for adsorption. 4 figs.

We performed XANES and EXAFS measurements at the sulfur K-edge for FeS, CuS and two coals, Powhatan {number_sign}5 and Blacksville {number_sign}2. We have used the measurements of the two standards in discussing the spectra of the spectra of the two coals as described below. We have continued our investigation for the possible bonding configurations of the SO{sub 2} molecule on CuO/Al{sub 2}O{sub 3}. In distinction to sulfur-to-metal (S-M) on-top bonding, we find that oxygen-to-metal (O-M) on-top bonding does provide a possible adsorption configuration of interest. We want next to investigate bridging type adsorption configurations. Before doing this, it is necessary to further examine the detailed behavior of the model for the clean CuO/Al{sub 2}O{sub 3} surface.

A menu driven automatic tank calibration program was established at one of the new facilities at the Savannah River Site (SRS). Approximately 100 tanks ranging in size from 10 to 21,000 liters were calibrated. Tank level instrumentation included a precision level system using Ruska instruments multiplexed to several tanks via a Scanivalve system, standard process level differential pressure transmitters, capacitance probes, and temperature devices. Most of the tank instruments were connected to data collection computers. Scales were temporarily connected to the data collection computers to input solution weights and to record the scale calibration data. Flat panel displays were used for information feedback to operators including when to transmit weighs, data transmitted, tank instrument readings, and other procedural steps. The automated data collection permitted signal averaging and consistency checks to improve the quality of the data and minimize repeat calibrations. This paper will provide a description of the calibration system, equipment used, unique features of the system, and an assessment of the quality of the data collected.

This report discusses: light scattering at the crystal-melt interface; morphological instability and pattern selection; and sidebranching.

There is an immediate need to begin to validate models that can be used for assessing the performance of waste package materials in an unsaturated repository environment. This paper examines available testing information and testing approaches that could support validation of models for engineering barrier system (EBS) radionuclide release. The content is presented in the context of the general methodology that has been proposed for validating performance assessment models. Available experimental observations are used to test some of the EBS release rate modeling premises. These observations include evidence of fluid film formation on waste glass surfaces in isothermal humid environments, accelerated waste glass reaction rates under repository service conditions of large glass surface area to water volume ratio, and mobilization of radionuclides as solutes and colloids. It is concluded that some important modeling premises may not be consistent with available experimental information. However, it is also concluded that future laboratory testing, which simulates the integrated waste package systems, is needed to evaluate the significance of these inconsistencies and to test the system level models. A small-scale apparatus which was developed and tested to examine the feasibility of laboratory analog testing for the unsaturated Yucca Mountain repository environment is described. 16 …

In this final report, we summarize some of our results from September 1989 to October 1990. The design, construction, and testing of a four-processor prototype multi-processor (RTP) board using TI TMS320C25 DSP chips has been completed and is reported upon in our separately submitted Final Report on the RADON TRANSFORM COMPUTER'' Project.'' The design of our fully custom CMOS VLSI chip has been completed. The chip has been designed, the layout completed, and the chip is now going through its final pre-fabrication simulations. We are now finishing the extensive detailed final documentation of the R/Bchip. This extensive documentation will be provided to Steve Azevedo when we have submitted the chip for fabrication. The present status of the custom chip design activity is summarized in Section II. Evaluations of the hardware requirements for fast filtering of data for filtered backprojection (item 3) have been completed and are summarized in our separately submitted Final Report on the RADON TRANSFORM COMPUTER'' Project.'' We briefly summarize the new custom CMOS VLSI unified Radon transform/backprojection IC architecture, layout, and simulated performance.

In this final report, we summarize some of our results from September 1989 to October 1990. The design, construction, and testing of a four-processor prototype multi-processor (RTP) board using TI TMS320C25 DSP chips has been completed. We are now finishing the extensive detailed final documentation of the RTP hardware and software. This extensive documentation will be provided to Steve Azevedo when we return the borrowed workstation and deliver the RTP to LLNL. A summary of the test results are in Section II. The design of our fully custom CMOS VLSI chip has been completed. The chip has been designed, the layout completed, and the chip is now going through its final pre-fabrication simulations. The present status of the custom chip design activity will be summarized in the separately submitted Final Report on the Real-Time Multi-Dimensional Processing Hardware Designs'' Project.'' Evaluations of the hardware requirements for fast filtering of data for filtered backprojection have been completed and are summarized. We briefly summarize the test results of the TMS320 multi-processor prototype RTP board evaluation.

To gain a fundamental understanding of the role and importance of hydrogen transfer reactions in thermal and catalytic coprocessing by examining possible hydrogen donation from cycloalkane/aromatic systems and by understanding the chemistry and enhanced reactivity of hydrotreated residuum, as well as by enriching petroleum solvent with potent new donors, nonaromatic hydroaromatics, thereby promoting hydrogen transfer reactions in coprocessing. The detailed results of experiments performed on several subtasks during the quarter are presented.

To gain a fundamental understanding of the role and importance of hydrogen transfer reactions in thermal and catalytic coprocessing by examining possible hydrogen donation from cycloalkane/aromatic systems and by understanding the chemistry and enhanced reactivity of hydrotreated residuum, as well as by enriching petroleum solvent with potent new donors, nonaromatic hydroaromatics, thereby promoting hydrogen transfer reactions in coprocessing. The detailed results of experiments performed on several subtasks during the quarter are presented.

The objective is to gain a fundamental understanding of the role and importance of hydrogen transfer reactions in thermal and catalytic coprocessing by examining possible hydrogen donation from cycloalkane/aromatic systems and by understanding the chemistry and enhanced reactivity of hydrotreated residuum, as well as by enriching petroleum solvent with potent new donors, nonaromatic hydroaromatics, thereby promoting hydrogen transfer reactions in coprocessing. The detailed results of experiments performed on several subtasks during the quarter are presented.

This paper describes the development of standards for emergency operations computer systems for the US Department of Energy (DOE). The proposed DOE computer standards prescribe the necessary power and simplicity to meet the expanding needs of emergency managers. Standards include networked UNIX workstations based on the client server model and software that presents information graphically using icons and windowing technology. DOE standards are based on those of the computer industry although Proposed DOE is implementing the latest technology to ensure a solid base for future growth. A case of how these proposed standards are being implemented is also presented. The Savannah River Site (SRS), a DOE facility near Aiken, South Carolina is automating a manual information system, proven over years of development. This system is generalized as a model that can apply to most, if not all, Emergency Operations Centers. This model can provide timely and validated information to emergency managers. By automating this proven system, the system is made easier to use. As experience in the case study demonstrates, computers are only an effective information tool when used as part of a proven process.

The objective of quantitative imaging is to provide pharmacokinetic information for patients that is analogous to that provided by biodistribution studies in mice. Radionuclide images depict the distribution of labeled antibodies in-vivo; thus the amount of radionuclide in a specific organ or site can be estimated by relating the counts detected in a defined region of interest to the total radionuclide content. This pharmacokinetic information can be used to obtain definitive and relevant answers to basic questions of importance for optimizing radioimmunoimaging and radioimmunotherapy and, in addition, can provide a data base from which to calculate the distribution of radiation absorbed doses. The research employs quantitative imaging in evaluating therapies. Quantitative imaging is performed by a certified nuclear medicine technician using the Siemens gamma camera interfaced with the microVAX II. The technician processes the imaging data and obtains pharmacokinetic information from it using programs developed by the authors and others. A large amount of data has been acquired and analyzed on the pharmacokinetics, dosimetry and toxicity of radiolabeled monoclonal therapy. Important dosimetry data on the whole body, marrow and tumor doses are available and all studies are archived so that they can be retrospectively analyzed. Although the radiation absorbed doses …