Geologic repositories for radioactive waste are evolving from conceptualization to the development of specific designs. Estimates of long-term hazards must be based upon quantitative predictions of environmental releases over time periods of hundreds of thousands of years and longer. This paper summarizes new techniques for predicting the long-term performance of repositories, it presents estimates of future environmental releases and radiation doses that may result for conceptual repositories in various geologic media, and it compares these predictions with an individual dose criterion of 10{sup -4} Sv/y. 50 references, 11 figures, 6 tables.

The Nevada Nuclear Waste Storage Investigations (NNWSI) Waste Package project is part of the US Department of Energy`s Civilian Radioactive Waste Management (CRWM) Program. The NNWSI project is working towards the development of multibarriered packages for the disposal of spent fuel and high-level waste in tuff in the unsaturated zone at Yucca Mountain at the Nevada Test Site (NTS). The final engineered barrier system design may be composed of a waste form, canister, overpack, borehole liner, packing, and the near field host rock, or some combination thereof. Lawrence Livermore National Laboratory`s (LLNL) role is to design, model, and test the waste package subsystem for the tuff repository. At the present stage of development of the nuclear waste management program at LLNL, the detailed requirements for the waste package design are not yet firmly established. In spite of these uncertainties as to the detailed package requirements, we have begun the conceptual design stage. By conceptual design, we mean design based on our best assessment of present and future regulatory requirements. We anticipate that changes will occur as the detailed requirements for waste package design are finalized. 17 references, 4 figures, 10 tables.

The Nevada Nuclear Waste Storage Investigations (NNWSI) project under the Civilian Radioactive Waste Management Program is planning a repository at Yucca Mountain at the Nevada Test Site for isolation of high-level nuclear waste. Lawrence Livermore National Laboratory is developing designs for an engineered barrier system containing several barriers such as the waste form, a canister and/or an overpack, packing, and near field host rock. In this paper we address the selection of metal containment barriers. 13 references, 4 tables.

At the Savannah River Nuclear Facility irradiated assemblies are conveyed through the air from the reactor to a discharge/entry channel, where they are immersed in water. This paper addresses the monitoring of the temperature of these assemblies while they are in transit during the discharge cycle. To accomplish this, a remotely controlled and monitored radiation-hardened thermal imaging and alarm system was installed at each reactor. The paper will discuss the system concept and operation. The program for radiation hardening and testing this equipment will be reviewed.

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In this report, data from neutron measurement and dosimetry studies performed by Pacific Northwest Laboratory, the Environmental Measurements Laboratory, and Rensselaer Polytechnic Institute are examined and compared. The purpose of this data correlation effort is to determine whether useful relationships exist between the actual neutron dose equivalent in a typical commercial nuclear power reactor and various measurement parameters, such as ratios of the response of 9-in. to 3-in. spheres, neutron/gamma ratios, albedo dosimeter response and neutron spectrometer readings. In most neutron radiation fields found in the reactors visited, the response of albedo dosimeters can be brought into reasonable agreement with dose equivalents measured with multispheres, tissue equivalent proportional counters (TEPCs) or remmeters. Because the responses of the remmeters, like the responses of albedo dosimeters, are energy dependent, it is preferable to correct the responses of the albedo dosimeters to agree with dose equivalents measured with either TEPCs or multispheres. If one of these laboratory systems has been used to measure neutron dose equivalents at a specific pressurized water reactor, a calculated average albedo dosimeter correction factor can be used for most locations at that reactor. However, if the measured 9-in. to 3-in. remmeter ratio is greater than 0.20, it is …

The behavior of a fluid undergoing a phase change from liquid to vapor while flowing through a duct is of interest to engineers in many practical situations. For the case of interest to us, geothermal hot water flowing through various channels (well bores, surface pipes, equipment, etc.) may reach its flash point and choke point under appropriate conditions. The proper design of energy conversion systems depends on the ability of the engineer to predict this behavior with an acceptable degree of accuracy. The present study was in part motivated by the task of designing the blow-down, two-phase fluid flow test facility at Brown University. In that facility, a refrigerant (dichlorotetrafluoroethane or R-114) is boosted to a selected stagnation state and allowed to flow through a nozzle orifice into a long straight tube. The operation relies on the fluid being choked at the inlet section, and under certain circumstances, at the downstream section as well. A simple schematic of the test section is shown. This paper treats the problem generically and analytically, making use of the basic laws of fluid mechanics and thermodynamics. Specific calculations have been performed using R-114 as the flowing medium. They attempt to identify and describe all …

The objective of the present study was to develop a one-dimensional, unsteady state model for coal-water mixture droplet combustion, and to compare the characteristic times for the various processes, such as water vaporization, devolatilization and char oxidation with available experimental data. A water film surrounding a spherical coal particle is considered to undergo vaporization by heat transfer from the hot air. After the water vaporization is complete, devolatilization begins. This process is assumed to be kinetically controlled. Water vaporization and devolatilization processes are modeled by using a hybrid Eulerian-Lagrangian method to obtain the properties of the gas-phase and the condensed-phase. An explicit finite difference scheme is used to solve the Eulerian gas-phase equation where as a Runga-Kutta scheme is employed to solve the Lagrangian condensed-phase equations. The predicted characteristic times for water vaporization is in good agreement with values proposed in the literature. At the present time there is insufficient data to draw any conclusions on the model. Methods are proposed to refine the simple kinetic model which takes into account pore diffusion and mass transfer for devolatilization and char oxidation. 9 references, 12 figures.

Analytic derivatives of the potential energy for Self-Consistent-Field (SCF) wave functions have been developed in recent years and found to be useful tools. The first derivative for configuration interaction (CI) wave functions is also available. This work details the extension of analytic methods to energy second derivatives for CI wave functions. The principal extension required for second derivatives is evaluation of the first order change in the CI wave function with respect to a nuclear perturbation. The shape driven graphical unitary group approach (SDGUGA) direct CI program was adapted to evaluate this term via the coupled-perturbed CI equations. Several iterative schemes are compared for use in solving these equations. The pilot program makes no use of molecular symmetry but the timing results show that utilization of molecular symmetry is desirable. The principles for defining and solving a set of symmetry adapted equations are discussed. Evaluation of the second derivative also requires the solution of the second order coupled-perturbed Hartree-Fock equations to obtain the correction to the molecular orbitals due to the nuclear perturbation. This process takes a consistently higher percentage of the computation time than for the first order equations alone and a strategy for its reduction is discussed.

We report results from neutral current scattering of muon neutrinos and antineutrinos on iron nuclei by the CCFRR experiment at Fermilab. Our objective is the measurement of sin/sup 2/theta/sub w/ from inclusive semileptonic neutrino-nucleon interactions. Such a measurement, even though it is subject to more corrections than the analogous measurement in neutrino-electron scattering (e.g. due to the presence of a strange quark sea in the nucleon), has a high degree of statistical accuracy and may afford the most precise test of the standard model of electro-weak interactions. Furthermore, the recent observations of the Z/sup 0/ and W/sup +-/ in proton-antiproton collisions give such a measurement added topical interest. The comparison of sin/sup 2/theta/sub w/ determined from the masses of the Z/sup 0/ and W/sup +-/ and from neutrino interactions, i.e. from different processes and energy regions, may hold some surprises. Finally, the grand-unified theories make definite predictions about the value of sin/sup 2/theta/sub w/ and the lifetime of the proton; sin/sup 2/theta/sub w/ measurements test the validity of these theories. The experiment was performed in Fermilab's dichromatic neutrino beam and utilized a large detector consisting of an iron-scintillator target calorimeter followed by a steel toroidal muon spectrometer.

Properly quantified performance of a solar-thermal cavity receiver must not only account for the energy gains and losses as dictated by the First Law of thermodynamics, but it must also account for the quality of that energy. However, energy quality can only be determined from the Second Law. In this paper an equation for the Second-Law efficiency of a cavity receiver is derived from the definition of available energy or availability (occassionally called exergy), which is a thermodynamic property that measures the maximum amount of work obtainable when a system is allowed to come into unrestrained equilibrium with the surrounding environment. The fundamental concepts of the entropy and availability of radiation are explored from which a convenient relationship among the reflected cone half angle, the insolation, and the concentrator geometric characteristics is developed as part of the derivation of the Second-Law efficiency. A comparison is made between First- and Second-Law efficiencies around an example of data collected from two receivers that were designed for different purposes. The author attempts to demonstrate that a Second-Law approach to quantifying the performance of a solar-thermal cavity receiver lends greater insight into the total performance than does the conventional First-Law method.

Research conducted at Giner, Inc. during 1981 to 1983 under the present contract has been a continuation of the investigation of a high temperature regenerable desulfurization process capable of reducing the sulfur content in coal gases from 200 ppM to 1 ppM. The overall objective has been the integration of a coal gasifier with a molten carbonate fuel cell, which requires that the sulfur content be below 1 ppM. Commercially available low temperature processes incur an excessive energy penalty. Results obtained with packed-bed and fluidized bed reactors have demonstrated that a CuO/ZnO mixed oxide sorbent is regenerable and capable of lowering the sulfur content (as H/sub 2/S and COS) from 200 ppM in simulated hot coal-derived gases to below 1 ppM level at 600 to 650/sup 0/C. Four potential sorbents (copper, tungsten oxide, vanadium oxide and zinc oxide) were initially selected for experimental use in hot regenerable desulfurization in the temperature range 500 to 650/sup 0/C. Based on engineering considerations, such as desulfurization capacity in per weight or volume of sorbents, a coprecipitated CuO/ZnO was selected for further study. A structural reorganization mechanism, unique to mixed oxides, was identified: the creation of relatively fine crystallites of the sulfided components (Cu/sub …

We have a simple perturbative picture of the production of hadrons from e/sup +/e/sup -/ annihilations which works quite well in predicting the main features of this interaction. It explains the magnitude of the total cross-section, the basic two-jet structure, and the final state angular distributions. It is also consistent with our present ideas about the structure of hadronic matter and the requirement that at high enough energies, the corrections due to strong interactions are small and hence treatable in a perturbative sense. We have seen, however, that to progress beyond this point requires a detailed model of fragmentation phenomena and that differences in models prevent us from making clean predictions about QCD. It is therefore important that we continue to study the fragmentation process and try to parameterize it as well as possible. Large amounts of experimental data are now available on this subject, and new tests will become available as experimenters look in more detail at the behavior of quantum number correlations and energy dependent effects. In doing this, it will be important to keep in mind that mass effects can yield significant energy variations in the model parameters. Our eventual goal should be to find ways of …

A comparison is made between the production of high intensity beams of helium-like uranium ions, U/sup 90 +/, by conventional and exotic ion sources, and by the foil stripping of highly accelerated ions output from the Bevalac. The parameter requirements are specified and compared to the parameters achievable by present day ion source technology. The EBIS (Electron Beam Ion Source) comes closest to satisfying the necessary parameters, and this possibility is considered in some detail. We conclude that existing and near-future ion source technology does not provide a means of production of high intensity U/sup 90 +/ beams. Foil stripping of lower charge state species that have been accelerated through the Bevalac provides a convenient approach.

Polystyrene-divinylbenzene (PS-DVB) based ion exchangers are commonly used in water demineralization or decontamination operations at nuclear facilities. Self-irradiation from sorbed radionuclides may affect the properties of radwaste containing these ion-exchange media. The effects of external irradiation on anion, cation, and mixed bed PS-DVB ion exchangers have been investigated under conditions relevant to radwaste storage and disposal. Three effects are emphasized in the present report: (1) release of acids, radionuclides or chemically aggressive species through radiolytic attack on the functional group, (2) radiolytic generation/uptake of corrosive or combustible gases, (3) effect of irradiation on solidification of resins in cement. Special consideration was placed on external variables such as radiation dose rate, resin chemical loading and moisture conditions, accessibility to atmospheric oxygen, and interactions in multicomponent systems. Such variables may affect the correspondence between laboratory results and field performance. 40 references, 24 figures, 28 tables.

As part of its contrast to design, build and operate the SRC-1 Demonstration Plant in cooperation with the US Department of Energy (DOE), International Coal Refining Company (ICRC) was required to collect and evaluate data related to wastewater streams and wastewater treatment procedures at the SRC-1 Pilot Plant facility. The pilot plant is located at Wilsonville, Alabama and is operated by Catalytic, Inc. under the direction of Southern Company Services. The plant is funded in part by the Electric Power Research Institute and the DOE. ICRC contracted with Catalytic, Inc. to conduct wastewater sampling. Tasks 1 through 5 included sampling and analysis of various wastewater sources and points of different steps in the biological treatment facility at the plant. The sampling program ran from May 1 to July 31, 1982. Also included in the sampling program was the generation and analysis of leachate from SRC product using standard laboratory leaching procedures. For Task 6, available plant wastewater data covering the period from February 1978 to December 1981 was analyzed to gain information that might be useful for a demonstration plant design basis. This report contains a tabulation of the analytical data, a summary tabulation of the historical operating data that …

This report first provides some background information on intrinsic point defects, and on carbon and oxygen in silicon in so far as it may be relevant for the efficiency of solar cells fabricated from EFG ribbon material. We discuss the co-precipitation of carbon and oxygen and especially of carbon and silicon self interstitials. A simple model for the electrical activity of carbon-self-interstitial agglomerates is presented. We assume that the self-interstitial content of these agglomerates determines their electrical activity and that both compressive stresses (high self-interstitial content) and tensile stresses (low self-interstitial content) give rise to electrical activity of the agglomerates. The self-interstitial content of these carbon-related agglomerates may be reduced by an appropriate high-temperature treatment and enhanced by a supersaturation of self-interstitials generated during formation of the p-n junction of solar cells. It is suggested that oxygen present in supersaturation in carbon-rich silicon may be induced to form SiO/sub 2/ precipitates by self-interstitials generated during phosphorus diffusion. It is proposed that the SiO/sub 2/-Si interface of the precipates gives rise to a continuum of donor states and that these interface states are responsible for at least part of the light-enhancement effects observed in oxygen containing EFG silicon after phosphorus diffusion.

We have measured relative line intensities of the K x-ray spectra of Si, Cl, and Ca from laser-produced plasmas to assess their usefulness as a plasma diagnostic. The different elements are added at low concentrations to CH disks which are irradiated at 5 x 10/sup 14/ W/cm/sup 2/ with a 0.53 ..mu..m laser pulse of 20 Joules at 1 nsec. The concentration of each element is kept low in order not to change the Z of the plasma, and therefore the plasma dynamics. The various spectra are measured with a time-resolved spectrograph to obtain line intensities as a function of time over the length of the laser pulse. These relative intensities of various He-like and H-like lines are compared with calculations from a steady-state level population code. The results give good consistency among the various line ratios. Agreement is not as good for analysis of the Li-like satellite lines. Modelling of the Li-like lines need further investigation. 10 references, 9 figures.

The purpose of this program is to investigate some of the basic physics and chemistry of the electron beam induced NO/sub x/ and SO/sub x/ removal process. The program involves both kinetic modelling and diagnostic development. The development of an adequate kinetic model is necessary in order to scale the laboratory results, which are currently available, to process conditions closer to those that will be encountered at full scale operation. It is also necessary in order to place the laboratory data on a firm theoretical foundation. The development of real time optical diagnostics is a necessary supporting task for these goals in order to obtain kinetic data on some of the myriad of species that are present in this hostile environment (X-rays present; hot, acidic gas) which is difficult to access by conventional methods. This particular NO/sub x//SO/sub x/ removal process involves the irradiation of combustion products t temperatures around 100/sup 0/C with a beam of high energy electrons. The current study expands upon the mechanistic studies. A detailed kinetic model is described which includes all the necessary assumptions that enter in order to take the very large number of possible processes that occur in e-beam irradiated mixtures and reduce …