The phenomena known as density-wave instability often occurs in phase change systems, such as boiling water nuclear reactors (BWRS). Our current understanding of density-wave oscillations is in fairly good shape for linear phenomena (eg, the onset of instabilities) but is not very advanced for non-linear phenomena [Lahey and Podowski, 1989]. In particular, limit cycle and chaotic instability modes are not well understood in boiling systems such as current and advanced generation BWRs (eg, SBWR). In particular, the SBWR relies on natural circulation and is thus inherently prone to problems with density-wave instabilities. The purpose of this research is to develop a quantitative understanding of nonlinear nuclear-coupled density-wave instability phenomena in BWRS. This research builds on the work of Achard et al [1985] and Clausse et al [1991] who showed, respectively, that Hopf bifurcations and chaotic oscillations may occur in boiling systems.

To safely and permanently store high-level nuclear waste, the potential Yucca Mountain repository site must mitigate the release and transport of radionuclides for tens of thousands of years. In the failure scenario of greatest concern, water would contact the waste package (WP), accelerate its failure rate, and eventually transport radionuclides to the water table. In a concept called the ``extended-dry repository,`` decay heat arising from radioactive waste extends the time before liquid water can contact a WP. Recent modeling and theoretical advances in nonisothermal, multiphase fracture-matrix flow have demonstrated (1) the critical importance of capillary pressure disequilibrium between fracture and matrix flow, and (2) that radioactive decay heat plays a dominant role in the ability of the engineered and natural barriers to contain and isolate radionuclides. Our analyses indicate that the thermo-hydrological performance of both the unsaturated zone (UZ) and saturated zone (SZ) will be dominated by repository-heat-driven hydrothermal flow for tens of thousands of years. For thermal loads resulting in extended-dry repository conditions, UZ performance is primarily sensitive to the thermal properties and thermal loading conditions and much less sensitive to the highly spatially and temporally variable ambient hydrologic properties and conditions. The magnitude of repository-heat-driven buoyancy flow in …

This paper describes a risk-based screening analysis that was performed on the Surry nuclear power station to evaluate the adequacy of technical specifications (TS) for PWRs during shutdown periods. Of particular concern was the risk sensitivity to allowable TS configurations while at reduced reactor coolant system inventory conditions since incidents have occurred in plants over recent years during this time. A typical refueling outage was analyzed to determine the plant configurations created due to surveillance testing and maintenance activities. The impact from single and multiple component outages were identified so their risk influence on the plant configuration could be assessed. From these results, generic insights into the efficiency of existing TS to control high risk configurations were obtained as well as the applicability and ability of the risk-based methodology employed to make that determination.

The results of the analysis of the JASPER Program Radial Shield Attenuation Experiment are presented. The experiment was performed in 1986 at the ORNL Tower Shielding Facility. It is the first of six experiments in this cooperative Japanese and American program in support of shielding designs for advanced sodium-cooled reactors. Six different shielding configurations and subconfigurations thereof were studied. The configurations were calculated with the DOT-IV two-dimensional discrete ordinates radiation transport computer code using the R-Z geometry option, a symmetric S{sub 12} quadrature (96 directions), and cross sections from ENDF/B versions IV and V in either a 51- or 61-group structure. Auxiliary codes were used to compute detector responses and prepare cross sections and source input for the DOT-IV calculations. Calculated detector responses were compared with measured responses and the agreement was good to excellent in many cases. However, the agreement for configurations having thick steel or B{sub 4}C regions or for some very large configurations was fair to poor. The disagreement was attributed to cross-section data, broad-group structure, or high background in the measurements. In particular, it is shown that two cross-section sets for ``B give very different results for neutron transmission through the thick B{sub 4}C regions used …

This report covers EPA proficiency samples, USGS proficiency samples, and Los Alamos samples (approx. 20 mineral, water samples from LANL).

A analytical model for describing dynamics of a gas bubble in the liquid sodium of a liquid-metal reactor as the result of failed fuel pins is discussed. A model to describe the coupled response of the liquid sodium surrounding the gas bubble is also discussed. The analysis method is programmed in a computer code and used to analyze some available experimental data, and the results are discussed.

Using the cosmic ray shadows of the sun and moon, we have estimated the angular resolution of the CYGNUS extensive air shower array. With the event sample now available we estimate the angular resolution of the array to be 0.70[sub [minus]0.06][sup [plus]0.07] degrees. The resolution depends on the total number of detected shower particles. A new parameterization of the measured shower-front timing structure and the use of counters with small pulse areas lead to a [approximately]25% improvement in the resolution. The systematic pointing error of the array is less than 0.4[degree].

Over 400 published papers, presentations at scientific meetings, and reports relating to the determination of sulfur and sulfur forms in coal-related materials have been accumulated, classified, and an evaluation made of their content.

The slab branch of the ITG mode was produced by a d.c. ion acceleration heating scheme and definitively identified in CLM under the previous DOE grant. A transit-time rf heating scheme was used to produce a more Maxwellian ion population to produce and identify a more predictable slab ITG mode. These experiments are partly based on some theoretical work on the substantial effects of anisotropy in [eta][sub i] on the slab mode. The progress under the present DOE grant are described below.

The masses coupling constants and cosmological parameters obtained using our discrete and combinatorial physics based on discrimination between bit-strings indicate that we can achieve the unification of quantum mechanics with relativity which had become the goal of twentieth century physics. To broaden our case we show that limitations on measurement of the position and velocity of an individual massive particle observed in a colliding beam scattering experiment imply real, rational commutation relations between position and velocity. Prior to this limit being pushed down to quantum effects, the lower bound is set by the available technology, but is otherwise scale invariant. Replacing force by force per unit mass and force per unit charge allows us to take over the Feynman-Dyson proof of the Maxwell Equations and extend it to weak gravity. The crossing symmetry of the individual scattering processes when one or more particles are replaced by anti-particles predicts both Coulomb attraction (for charged particles) and a Newtonian repulsion between any particle and its anti-particle. Previous quantum results remain intact, and predict the expected relativistic fine structure and spin dependencies. Experimental confirmation of this anti-gravity prediction would inaugurate the physics of the twenty-first century.

The masses coupling constants and cosmological parameters obtained using our discrete and combinatorial physics based on discrimination between bit-strings indicate that we can achieve the unification of quantum mechanics with relativity which had become the goal of twentieth century physics. To broaden our case we show that limitations on measurement of the position and velocity of an individual massive particle observed in a colliding beam scattering experiment imply real, rational commutation relations between position and velocity. Prior to this limit being pushed down to quantum effects, the lower bound is set by the available technology, but is otherwise scale invariant. Replacing force by force per unit mass and force per unit charge allows us to take over the Feynman-Dyson proof of the Maxwell Equations and extend it to weak gravity. The crossing symmetry of the individual scattering processes when one or more particles are replaced by anti-particles predicts both Coulomb attraction (for charged particles) and a Newtonian repulsion between any particle and its anti-particle. Previous quantum results remain intact, and predict the expected relativistic fine structure and spin dependencies. Experimental confirmation of this anti-gravity prediction would inaugurate the physics of the twenty-first century.

The RF and other manipulations required to extract antiprotons from the Accumulator core for Collider operation are described. ESME simulations of the motion in longitudinal phase space are shown. Measurements of the emittances of the extracted antiprotons are presented. The effect of the unstacking process on the core longitudinal and transverse emittances is examined and recent performance is also presented.

Careful Cu K-edge X-ray absorption fine structure (XAFS) measurements on oriented powders of YBa[sub 2]CU[sub 3]O[sub 7[minus]] were made as a function of temperature, of [delta], [Tc] method of preparation and grain size. The XAFS data were analyzed for the Cu(1) - O(4) apical bond distance distribution. AU samples indicated evidence for a double-peak in the distribution with a splitting of 0.1[Angstrom], with the clearest case for the [delta] [approx] 0 samples occurring for the [Tc] = 89K 20[mu]m grain samples and the least clear one for the 5[mu]m grain [Tc] = 93K sample. There is no significant temperature dependence of the splitting. Because the XAFS evidence for the splitting depends on a small signal, it is prudent to verify its existence by other independent measurements.

This invention is comprised of an apparatus for detecting the presence of a liquid in a region, including an electrically passive sensor adapted for contacting the liquid, and an electrically active detector. The sensor is a circuit with a pair of spaced-apart terminals connected to a switch that closes in the presence of the liquid. The detector carries an alternating current with a resonant frequency. When the sensor is placed in a region and liquid is present, the circuit of the sensor is closed. By bringing the detector close to the sensor, an alternating current is induced in the sensor that will, in turn, alter the resonant frequency of the detector. This change is signaled by a transducer. The switch can operate by a change in conductivity of a material between the terminals of the sensor or by expansion of a liquid absorber that pushes the two terminals together, or by a change in the conductivity of the space between the terminals as a result of the liquid. The detector generates an audible or visible signal, or both, in response to the current change.

Neutron dose equivalent rates have been measured for 800-MeV proton beam spills at the Los Alamos Meson Physics Facility. Neutron detectors were used to measure the neutron dose levels at a number of locations for each beam-spill test, and neutron energy spectra were measured for several beam-spill tests. Estimates of expected levels for various detector locations were made using a simple analytical model developed for 800-MeV proton beam spills. A comparison of measurements and model estimates indicates that the model is reasonably accurate in estimating the neutron dose equivalent rate for simple shielding geometries. The model fails for more complicated shielding geometries, where indirect contributions to the dose equivalent rate can dominate.

A simple parameter estimation method has been developed to determine the dispersion and velocity parameters associated with stream/river transport. The unsteady one dimensional Burgers' equation was chosen as the model equation, and the method has been applied to recent Savannah River dye tracer studies. The computed Savannah River transport coefficients compare favorably with documented values, and the time/concentration curves calculated from these coefficients compare well with the actual tracer data. The coefficients were used as a predictive capability and applied to Savannah River tritium concentration data obtained during the December 1991 accidental tritium discharge from the Savannah River Site. The peak tritium concentration at the intersection of Highway 301 and the Savannah River was underpredicted by only 5% using the coefficients computed from the dye data.

Atmospheric Studies in Complex Terrain (ASCOT) program sponsored a field experiment in the winter of 1991 near Rocky Flats, Colorado. Both meteorological and tracer dispersion measurements were taken. These two data sets provided an opportunity to investigate the influence of terrain-generated, radiatively-driven flows on the dispersion of the tracer. We use the Regional Atmospheric Modeling System (RAMS), originally developed at Colorado State University, to simulate meteorological conditions and tracer dispersion on the case night of 4-5 February 1991. The simulations described herein reveal considerable information about the extent to which the Rocky Mountains influence the flow along the Front Range , the importance of diffusion when simulating drainage flows and the computing needs of simulations in complex terrain regions.

At Los Alamos National Laboratory (LANL), facility waste streams tend to be small but highly diverse. Initial characterization of such waste streams is often difficult in part due to a lack of tools to assist the generators themselves in completing such assessments. A methodology has been developed at LANL to allow process knowledgeable field personnel to develop baseline waste generation assessments and to evaluate potential waste minimization technology. This Process Waste Assessment (PWA) system is an application constructed within the Process Modeling System and currently being integrated with the InFoCAD Geographic Information System (GIS) . The Process Modeling System (PMS) is an object-oriented, mass balance-based, discrete-event simulation framework written using the Common Lisp Object System (CLOS) . Analytical capabilities supported within the PWA system include: complete mass balance specifications, historical characterization of selected waste streams and generation of facility profiles for materials consumption, resource utilization and worker exposure. Development activities include integration with the LANL facilities management Geographic Information System (GIS) and provisions for a Best Available Technologies (BAT) database. The environments used to develop these assessment tools will be discussed in addition to a review of initial implementation results.

The State Oversight Program's straddle packer sampling system was tested at the Idaho National Engineering Laboratory during July--September, 1992, in USGS monitoring well No. 44. The straddle packer was designed for the Oversight Program's ground water research program, to provide a means of characterizing the vertical hydraulic and water quality variations believed to exist in the eastern Snake River Plain aquifer beneath the Idaho National Engineering Laboratory. During the field program, tracer introduction and recovery experiments were conducted to evaluate QA sampling objectives as well as to assess the feasibility of obtaining additional information on aquifer/borehole characteristics such as specific discharge through different aquifer zones, integrity of packer seals, etc. A total of twelve tracer tests were performed on six different intervals from 467 to 600 feet below land surface (ft bls). Lithium bromide powder dissolved in de-ionized water was used as a tracer. All tracer tests were conducted in two phases: Emplacement -- introduction of a slug of a known quantity of tracer, followed by continuous mixing within the test interval for periods ranging from 8 to 72 minutes (without pumping to surface), during which time the tracer was diluted by ground water advection through the test interval; and …

The Field Lysimeter Investigations: Low-Level Waste Data Base Development Program is obtaining information on the performance of radioactive waste in a disposal environment. Waste forms fabricated using ion-exchange resins from EPICOR-II are being tested to develop a low-level waste data base and to obtain information on survivability of waste forms in a disposal environment. The program includes examining radionuclide releases from waste forms in the first seven years of sampling. Also, lysimeter data are applied to performance assessment source term models, and initial results from use of data in two models are being studied.

The United States Department of Energy's (USDOE's) K-reactor, a defense production reactor located at the Savannah River Site in Aiken, South Carolina, was shut down in the summer of 1988 for safety upgrades to bring it into conformance with modern safety standards prior to restart. Over the course of the succeeding four years, all aspects of the 35-year old reactor, including hardware, operations, and analysis, were upgraded to ensure that the reactor could operate safely according to standards similar to those applied to modern nuclear reactors. This paper describes the decision making processes by which issues were identified, priorities assigned, and analysis improved to enhance reactor safety. Special emphasis is given to the probabilistic risk assessment (PRA) decision making processes used to quantify the risks and consequences of operating the K-reactor, the analytical hierarchy process (AHP) used to identify key phenomena, and modifications made to the RELAP5 computer code to make it applicable to K-reactor analysis. The success of the project was demonstrated when the K-reactor was restarted in the summer of 1992.

This paper discusses the application of precision mounting and alignment techniques to a moderate energy beam transport system (MEBT) used on the exit of a 1.75 MeV RFQ. While frequently found in optical systems, techniques-such-as kinematic mounting, and degree-of-freedom decoupling, are not as widely used for accelerator components. The MEBT consist of one permanent magnet quadrupole, four electro magnet quadrupole, and one debuncher cavity. Included in the paper are discussions of design and fabrication considerations as well as, installation, alignment and operations experience during the successful implementation on a working accelerator.

Resonance Raman spectroscopy (RRS) potentially possesses many of the characteristics of an ideal verification technology. Some of these ideal traits are: very high selectivity and specificity to allow the deconvolution of a mixture of the chemicals of interest, high sensitivity in order to measure a species at trace levels, high reliability and long-term durability, applicability to a wide range of chemicals capability for sensing in a variety of environmental conditions, independence of the physical state of the chemical capability for quantitative analysis, and finally, but no less important capability for full signal development within seconds. In this presentation, the potential of RRS as a detection/identification technology for chemicals pertinent to nuclear materials production and processing will be assessed. A review of the basic principles behind this technique, both theoretical and experimental, will be discussed along with some recent results obtained in this laboratory. Raman scattering is a coherent, inelastic, two-photon scattering process where an exciting photon of energy hv promotes a molecule to a virtual level and the subsequently emitted photon is shifted in frequency in accordance with the rotational-vibrational structure of the irradiated species, therefore providing a unique fingerprint of the molecule. The enhancement of a Raman signal occurs …

Multi-well pumping tests have been concluded at wells MW79, MW108, and PW1 at the Paducah Gaseous Diffusion Plant (PGDP) to determine the hydraulic properties of the Regional Gravel Aquifer (RGA). Soil cores suggest that the RGA consists of a thin sandy facies (2 to 6 feet) at the top of a thicker (> 10 feet) gravelly facies. Previous analyses have not considered any permeability contrast between the two facies. To assess the accuracy of this assumption, TVA personnel conducted borehole flowmeter tests at wells MW108 and PW1. Well MW79 could not be tested. The high K sand unit is probably 10 times more permeable than comparable zone in the gravelly portion of the RGA. Previous analyses of the three multi-well aquifer tests do not use the same conceptual aquifer model. Data analysis for one pumping test assumed that leakance was significant. Data analysis for another pumping test assumed that a geologic boundary was significant. By collectively analyzing all three tests with the borehole flowmeter results, the inconsistency among the three pumping tests can be explained. Disparity exists because each pumping test had a different placement of observation wells relative to the high K zone delineating by flowmeter testing.