A computer program, SCAP-BR, has been developed at Burns and Roe for the gamma-ray streaming analysis through multi-legged ducts. SCAP-BR is a modified version of the single scattering code, SCAP, incorporating capabilities of handling multiple scattering and volumetric source geometries. It utilizes the point kernel integration method to calculate both the line-of-sight and scattered gamma dose rates by employing the ray tracing technique through complex shield geometries. The multiple scattering is handled by a repeated process of the single scatter method through each successive scatter region and collapsed pseudo source meshes constructed on the relative coordinate systems. The SCAP-BR results have been compared with experimental data for a Z-type (three-legged) concrete duct with a Co-60 source placed at the duct entrance point. The SCAP-BR dose rate predictions along the duct axis demonstrate an excellent agreement with the measured values.

A general expression is given for the stop bandwidths, ..delta nu../sub N/, of nonlinear beam-beam resonances, which is expanded in powers of Y(s), the vertical beam orbit, and which is valid under certain assumptions regarding the orbits and charge distributions near the interaction regions. This result is applied to obtain results for the rms ..delta nu../sub N/ due to random vertical orbit errors, and due to random errors in ..beta../sub y/ at the crossing points. Numerical results are given for the ISABELLE storage accelerator.

During this second quarter, meetings were held with contractors on the ERDA Fuel Gas from Animal Waste Program to discuss project planning and review. Site visits were made to groups involved in anaerobic digestion. An engineering and economic analysis of a process for the anaerobic digestion of animal residue was completed; the results can be used for the design of a pilot plant unit. A comprehensive engineering report of this analysis was completed, and a first draft was submitted to ERDA. Several proposals were received from ERDA and reviewed.

The Mirror Advanced Reactor Study (MARS) has resulted in an overview of a first-generation tandem mirror reactor. The central cell fusion plasma is self-sustained by alpha heating (ignition), while electron-cyclotron resonance heating and negative ion beams maintain the electrostatic confining potentials in the end plugs. Plug injection power is reduced by the use of high-field choke coils and thermal barriers, concepts to be tested in the Tandem Mirror Experiment-Upgrade (TMX-U) and Mirror Fusion Test Facility (MFTF-B) at Lawrence Livermore National Laboratory.

Conversion electrons from the decay of low-lying levels of /sup 237/Np have been measured to detect the population of these levels by gamma-ray decay of the /sup 237/Np shape isomer. Analysis of the 208-keV transition L conversion-electron peak gives an upper limit of about 17 ..mu..b for the population of the 3/2/sup -/ 267-keV level in /sup 237/Np from the shape isomer decay. Model calculations are compared with the measured limit. Improvements are suggested for this experiment. 9 refs., 4 figs.

Nationwide, the demand for electricity due to population and industrial growth is on the rise. However, climate change and air quality issues raise serious questions about the wisdom of addressing these shortages through the construction of additional fossil fueled power plants. In 1997, the President's Committee of Advisors on Science and Technology Energy Research and Development Panel determined that restoring a viable nuclear energy option was essential and that the DOE should implement a R&D effort to address principal obstacles to achieving this option. This work has addressed the need for improved thermal/fluid analysis capabilities, through the use of computational fluid dynamics, which are necessary to support the design of generation IV gas-cooled and supercritical water reactors.

This research and development program was designed to improve nondestructive evaluation of large mechanical objects by providing both fast and thermal neutron sources for radiography. Neutron radiography permits inspection inside objects that x-rays cannot penetrate and permits imaging of corrosion and cracks in low-density materials. Discovering of fatigue cracks and corrosion in piping without the necessity of insulation removal is possible. Neutron radiography sources can provide for the nondestructive testing interests of commercial and military aircraft, public utilities and petrochemical organizations. Three neutron prototype neutron generators were designed and fabricated based on original research done at the Lawrence Berkeley National Laboratory (LBNL). The research and development of these generators was successfully continued by LBNL and Adelphi Technology Inc. under this STTR. The original design goals of high neutron yield and generator robustness have been achieved, using new technology developed under this grant. In one prototype generator, the fast neutron yield and brightness was roughly 10 times larger than previously marketed neutron generators using the same deuterium-deuterium reaction. In another generator, we integrate a moderator with a fast neutron source, resulting in a high brightness thermal neutron generator. The moderator acts as both conventional moderator and mechanical and electrical support structure …

X-ray diffraction and infrared data have been collected froma sample of ettringite from ambient pressure to 6.4 GPa. The sample wasfound to reversibly transform to an amorphous phase at 3 GPa. Theisothermal bulk modulus of ettringite was found to be 27(7) GPa and theincompressibilities of the lattice parameters were found to be 71(30) GPaalong a and 108(36) GPa along c.

Charge-changing and fragment production cross sections at 0degrees have been obtained for interactions of 290, 400, and 650MeV/nucleon 40Ar beams, 650 and 1000 MeV/nucleon 35Cl beams, and a 1000MeV/nucleon 48Ti beam. Targets of C, CH2, Al, Cu, Sn, and Pb were used.Using standard analysis methods, we obtain fragment cross sections forcharges as low as 8 for Cl and Ar beams, and as low as 10 for the Tibeam. Using data obtained with small-acceptance detectors, we reportfragment production cross sections for charges as low as 5, corrected foracceptance using a simple model of fragment angular distributions. Withthe lower-charged fragment cross sections, we cancompare the data topredictions from several models (including NUCFRG2, EPAX2, and PHITS) ina region largely unexplored in earlier work. As found in earlier workwith other beams, NUCFRG2 and PHITS predictions agree reasonably wellwith the data for charge-changing cross sections, but do not accuratelypredict the fragment production cross sections. The cross sections forthe lightest fragments demonstrate the inadequacy of several models inwhich the cross sections fall monotonically with the charge of thefragment. PHITS, despite not agreeing particularly well with the fragmentproduction cross sections on average, nonetheless qualitativelyreproduces somesignificant features of the data that are missing from theother models.

Risk estimates derived from epidemiological studies of exposed populations, as well as the maximum permissible doses allowed for occupational exposure and exposure of the public to ionizing radiation are all based on the assumption that the human population is uniform in its radiosensitivity, except for a small number of individuals, such as ATM homozygotes who are easily identified by their clinical symptoms. The hypothesis upon which this proposal is based is that the human population is not homogeneous in radiosensitiviry, but that radiosensitive sub-groups exist which are not easy to identify. These individuals would suffer an increased incidence of detrimental radiation effects, and distort the shape of the dose response relationship. The radiosensitivity of these groups depend on the expression levels of specific proteins. The plan was to investigate the effect of 3 relatively rare, high penetrate genes available in mice, namely Atm, mRad9 & Brca1. The purpose of radiation protection is to prevent! deterministic effects of clinical significance and limit stochastic effects to acceptable levels. We plan, therefore to compare with wild type animals the radiosensitivity of mice heterozygous for each of the genes mentioned above, as well as double heterozygotes for pairs of genes, using two biological endpoints: …

The 600-233 waste site consisted of three small-diameter pipelines within the 600-232 waste site, including previously unknown diesel fuel supply lines discovered during site remediation. The 600-233 waste site has been remediated to achieve the remedial action objectives specified in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

Efforts to reduce the flux of Sr-90 to the Columbia River from Hanford Site 100-N Area past-practice liquid waste disposal sites have been underway since the early 1990s. Termination of all liquid discharges to the ground in 1993 was a major step toward meeting this goal. However, Sr-90 adsorbed on aquifer solids beneath liquid waste disposal sites and extending beneath the near-shore riverbed remains a continuing contaminant source to groundwater and the Columbia River. The initial pump-and-treat system proved to be ineffective as a long-term solution because of the geochemical characteristics of Sr-90. Following an evaluation of potential Sr-90 treatment technologies and their applicability under 100-NR-2 Operable Unit hydrogeologic conditions, the U.S. Department of Energy and the Washington State Department of Ecology agreed to evaluate apatite sequestration as the primary remedial technology, combined with a secondary polishing step utilizing phytoextraction if necessary. Aqueous injection was initiated in July 2005 to assess the efficacy of in-situ apatite along the 100 m of shoreline where Sr-90 concentrations are highest. The remedial technology is being developed by Pacific Northwest National Laboratory. CH2M Hill Plateau Remediation Company is implementing this technology in the field with support from PNNL.

We have reexamined our previously published data to search for evidence of correlations between the rates for the alpha, beta-minus, beta-plus, and electron capture decays of 22Na, 44Ti, 108Agm, 121Snm, 133Ba, and 241Am and the Earth?Sun distance. We find no evidence for such correlations and set limits on the possible amplitudes of such correlations substantially smaller than those observed in previous experiments.

This work describes developments in the application of Raman scattering and surface-enhanced Raman scattering (SERS) towards the assessment/characterization of carbon in soil. In the past, the nonspecific total carbon mass content of soil samples has generally been determined through mass loss techniques and elemental analysis. However, because of the concern over CO{sub 2} buildup in the atmosphere and its possible role in the ''Greenhouse Effect,'' there is a need for better-defined models of global cycling of carbon. As a means towards this end, there is a need to know more about the structure and functionality of organic materials in soil. Raman spectroscopy may therefore prove to be an exceptional tool in soil carbon analysis. Based on vibrational transitions of irradiated molecules, it provides structural information that is often suitable for sample identification. Furthermore, Raman scattering yields very fine spectral features which offer the potential for multicomponent sample analysis with minimal or no sample pretreatment. Although the intensity of Raman scattering is generally extremely low, the surface-enhanced Raman scattering (SERS) effect can greatly enhance Raman signals (10{sup 6}-10{sup 8} range) through the adsorption of compounds on specially roughened metal surfaces. In our laboratory, we have investigated copper, gold and silver as …

We present experimental data of electron energy distributions from ultra-intense (>10{sup 19} W/cm{sup 2}) laser-solid interactions using the Rutherford Appleton Laboratory Vulcan petawatt laser. These measurements were made using a CCD-based magnetic spectrometer. We present details on the distinct effective temperatures that were obtained for a wide variety of targets as a function of laser intensity. It is found that as the intensity increases from 10{sup 17} W/cm{sup 2} to 10{sup 19} W/cm{sup 2}, a 0.4 dependence on the laser intensity is found. Between 10{sup 19} W/cm{sup 2} and 10{sup 20} W/cm{sup 2}, a gradual rolling off of temperature with intensity is observed.

Resonance enhancement of the quantum efficiency of new polarized electron photocathodes based on a short-period strain-compensated AlInGaAs/GaAsP superlattice structure is reported. The superlattice is a part of an integrated Fabry-Perot optical cavity. We demonstrate that the Fabry-Perot resonator enhances the quantum efficiency by up to a factor 10 in the wavelength region of the main polarization maximum. The high structural quality implied by these results points to the very promising application of these photocathodes for spin-polarized electron sources.

Reversible photoinduced electron paramagnetic resonance (EPR) signals and photoconductivity were observed when a solution of tetracyancethylene (TCNE) in tetrahydrofuran (THF) was irradiated in the charge-transfer band of the complex formed between these two compounds. The eleven-line hyperfine structure of the EPR spectrum which was obtained demonstrated the presence of TCNE negative ion radical. The concentration of this radical was found to be directly proportional to the square root of the light intensity. Second order decay kinetics were followed when the light was shut off. Both the EPR signal and the photoconductivity rose initially as the square of the time. The latter portions of the growth curves could be fit to the latter portions of a hyperbolic tangential growth curve. From these data a reaction mechanism was proposed. The rate law dn/dt + kn{sup 2} = {alpha}L(1-e{sup -{beta}t}) = 0, where n = the concentration of radicals, t = the time, k, {alpha}, and {beta} are rate constants, and L = the light intensity, described both the photo-induced EPR and the photoconductivity within the limits of experimental accuracy.

A high resolution soft x-ray photoelectron spectroscopic study of Ga and As 3d core levels has been conducted for Fe/GaAs (001) as a function of Fe thickness. This work has provided unambiguous evidence of substrate disrupting chemical reactions induced by the Fe overlayer--a quantitative analysis of the acquired spectra indicates significantly differing behavior of Ga and As during Fe growth, and our observations have been compared with existing theoretical models. Our results demonstrate that the outdiffusing Ga and As remain largely confined to the interface region, forming a thin intermixed layer. Whereas at low coverages Fe has little influence on the underlying GaAs substrate, the onset of substrate disruption when the Fe thickness reaches 3.5 {angstrom} results in major changes in the energy distribution curves (EDCs) of both As and Ga 3d cores. Our quantitative analysis suggests the presence of two new As environments of metallic character; one bound to the interfacial region and another which, as confirmed by in-situ oxidation experiments, surface segregates and persists over a wide range of overlayer thickness. Analysis of the corresponding Ga 3d EDCs found not two, but three new environments--also metallic in nature. Two of the three are interface-resident whereas the third undergoes …

Pacific Northwest National Laboratory (PNNL) and National Renewable Energy Laboratory (NREL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially-available catalysts or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially-available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. A total of 28 tests were conducted to evaluate 22 different promoters as well as an unpromoted catalyst. The following general trends were observed for the test results: • The highest carbon selectivity to C2+ oxygenates occurred at the lowest reaction temperatures and accompanying lowest space time yields (STYs). • The lowest carbon selectivity to C2+ oxygenates occurred at the highest reaction temperatures because of high carbon conversion to hydrocarbons. • The highest C2+-oxygenate STYs occurred between 300°C and 325°C, with the gas hourly space velocity (GHSV) adjusted when necessary to maintain carbon conversion ranges between ~ 30 and 40 percent. Higher carbon selectivity to hydrocarbons at higher temperatures resulted in lower C2+-oxygenate STYs. • When catalysts were heated to between 300°C and 325°C the catalysts showed evidence of some deactivation …

As computation scales beyond terascale, the scientific problems under study through computing are increasingly pushing the boundaries of human knowledge about the physical world. It is more pivotal than ever to quickly and reliably extract new knowledge from these complex simulations of ultra scale. In this project, the PI expanded the traditional notion of transfer function, which maps physical quantities to visual cues via table look-ups, to include general temporal as well as multivariate patterns that can be described procedurally through specialty mini programming languages. Their efforts aimed at answering a perpetual question of fundamental importance. That is "what a visualization should show". Instead of waiting for application scientists to initiate the process, the team at University of Tennessee worked closely with scientists at ORNL in a proactive role to envision and design elegant, powerful, and reliable tools that a user can use to specify "what is interesting". Their new techniques include visualization operators that revolve around correlation and graph properties, relative patterns in statistical distribution, temporal regular expressions, concurrent attribute subspaces and traditional compound boolean range queries. The team also paid special attention to ensure that all visualization operators are inherently designed with great parallel scalability to handle tera-scale …

The paramagnetic 1:1 coordination complexes of (C5Me5)2Ybwith a series of 4,4'-disubstituted bipyridines, bipy-X, where X is Me,tert-Bu, OMe, Ph, CO2Me, and CO2Et have been prepared. All of thecomplexes are paramagnetic and the values of the magnetic susceptibilityas a function of temperature show that these values are less thanexpected for the cation, [(C5Me5)2Yb(III)(bipy-X)]+, which have beenisolated as the cation-anion ion-pairs[(C5Me5)2Yb(III)(bipy-X)]+[(C5Me5)2YbI2]f fnfn where X is CO2Et, OMe andMe. The 1H NMR chemical shifts (293 K) for the methine resonances locatedat the 6,6' site in the bipy-X ring show a linear relationship with thevalues of chiT (300 K) for the neutral complexes which illustrates thatthe molecular behavior does not depend upon the phase with one exception,viz., (C5Me5)2Yb(bipy-Me). Single crystals of the 4,4'-dimethylbipyridinecomplex undergo an irreversible, abrupt first order phase change at 228 Kthat shatters the single crystals. The magnetic susceptibility,represented in a delta vs. T plot, on this complex, in polycrystallineform undergoes reversible abrupt changes in the temperature regime 205 -212 K, which is suggested to be due to the way the individual molec ularunits pack in the unit cell. A qualitative model is proposed thataccounts for the sub-normal magnetic moments in theseytterbocene-bipyridine complexes.

We have carefully evaluated several processes that might be suitable for uranium recovery from thorium metal, and have chosen two that hold great promise. Both are simple non-aqueous methods that can readily be performed by remote means, and both require only a few simple process steps.

Assembly power limits are prescribed for each reactor charge so that the Emergency Cooling System (ECS) will prevent core damage from exceeding specified damage limits during a postulated loss-of-coolant (LOCA) or loss-of-pumping (LOPA) accident. Generic assembly power limits which include a 10% uncertainty factor have been determined for the Mark 16B-31 charge. However, future power limits will not be based on the values, because a new damage model is being developed. These limits can be determined at present if the minimum assembly flows during a LOCA are known.

The radiological aspects of a proposal to recover some of the heat now wasted in cooling water from the Hanford reactors by using the hot water as boiler feed for the steam plants in the 100 Areas are evaluated. The radioactive material in the hot effluent water will contaminate the boiler feed water system, cause additional radiation exposure of personnel, and increase the cost of maintenance and radiation protection, but very little radioactive material will be carried over into the steam system. At present steam loads, this proposal is economically attractive; other proposals being considered may nullify any savings from this one. 21 refs., 1 fig., 10 tabs.