The Lake Charles and Port Arthur quadrangles cover approximately 10,950 square miles of land west of the Mississippi River delta area. The area overlies thick sections of the Gulf of Mexico Basin. Surficial exposures are dominated by Recent and Pleistocene sediment. A search of available literature revealed no known uraniumdeposits. A total of 82 uranium anomalies were detected and are discussed briefly in this report. None were considered significant and all appear to relate to cultural features. Magnetic data appear to be in agreement with existing structural interpretations of the area.
The principal types of uraniumdeposits in Ontario are carbonatites and fenites, alkalic volcanic rocks, pegiatites, calc-silicate rocks, pyritic quartz-pebble conglomerates, polymictic conglomerates and some pelitic rocks, and various 'pitchblende' deposits including late Precambrian unconformities, possibly late Precambrian diabase dikes, and other unconformities: carbonates, sandstones, lignites, and semi-pelitic rocks of middle and upper Precambrian age. Only red unzoned pegmatite and the pyritic quartz-pebble conglomerate have supported production. Ontario reasonably assured and estimated resources in the economic and subeconomic categories in 1977 amounted to 553 000 tonnes U, and 1977 production was 4000 tonnes U. Measured, indicated, and inferred resources in the Elliot Lake - Agnew Lake area are at least 400 000 tonnes U. The latter deposits are also a ...
A methodology for the determination of the rare earth elements in uranium oxides by ion microprobe has been set up on a Cameca ims-3f instrument. An uranium oxide reference material from a syn-metamorphic uraniumdeposit related to albitisation has also been developed for this type of analysis. Applications of the methodology are presented for a series of uranium oxides selected from some major uraniumdeposit types: from the world's highest grade unconformity-related uraniumdeposit from the Athabasca Basin (Saskatchewan, Canada; the Shea Creek and the McArthur River examples), a perigranitic vein-type deposit (Pen Ar Ran, Vendee, France) and a volcanic caldera-related deposit (Streltsovkoye, Transbaikalia, Russia). Each type of uranium ...
The report is divided into six working group discussions on the following subjects: 1) Chemical and physical mechanisms in the formation of uranium mineralization, geochronology, isotope geology and mineralogy; 2) Sedimentary basins and sandstone-type uraniumdeposits; 3) Uranium in quartz-pebble conglomerates; 4) Vein and similar type deposits (pitchblende); 5) Other uraniumdeposits; 6) Relation of metallogenic, tectonic and zoning factors to the origin of uraniumdeposits. Each working group paper contains a short introductory part followed by a discussion by the working group members.
The Yaojia Formation recovered by CCSD-SK-Is borehole (China Cretaceous Continental Scientific Drilling-SongkeI-the south borehole) is 157.67 m long and 99.96% of cores recovery. The age of the formation corresponds with a range from the Santonian to the early Campanian. The sequences and processes of lithology-lithofacies and cyclic stratigraphy are revealed by a detailed core description. Eleven rock types and three kinds of sedimentary subfacies, including shallow lake, deep lake, and delta front, are recognized from the drilling core. There are eleven sedimentary microfacies including dolostone, argillaceous limestone, shallow lake turbidite, deep lake turbidite, subaqueous mouth bar, distal bar, sheet sandstone, subaqueous distributary bay, slump deposits, shallow lake mudstone, and d...
Uranium has varying degrees of oxidation (+4 and +6) and is responsive to changes in the redox potential of the environment. It is deposited at the reduction barrier with the participation of biota and at the sorption barrier under oxidative conditions. Iron (hydr)oxides are the strongest sorbents of uranium. Uranium, being an element of medium biological absorption, can accumulate (relative to thorium) in the humus horizons of some soils. The high content of uranium in uncontaminated soils is most frequently inherited from the parent rocks in the regions of positive U anomalies: in the soils developed on oil shales and in the marginal zone of bogs at the reduction barrier. The development of nuclear and coal-fired power engineering resulted in the environmental contamination with uranium....
Environmental research related to uranium tailings is being carried out within the Mining Research Laboratories and Mineral Sciences Laboratories of CANMET, EMR. Field-related research on uranium tailings has been conducted at Elliot Lake for over five years. Much of the work has been focused on a program to rehabilitate pyritic tailings. This has resulted in developing a practicable technology for growing vegetation on such wastes. Limitations have been small size of the test-plots and the relatively short period during which experiments have been carried out. A research program aimed at identifying and reducing acidic and radioactive effluents is also underway at Elliot Lake. These liquid effluents have been identified as the most serious threat to the environment. Research at the Mineral Sciences Laboratories and its predecessor divisions relating to the processing of uranium and ...
High-resolution sequence stratigraphy taking base-level cycles as interface of reference was developed rapidly in recent years. Its greatest predominance lies in that it can be applied to multi-controled continental sedimentary basins and can effectively improve accuracy and distinguishability of sequence stratigraphy analysis. Principles of base-level cycles can also be applied to the research and practice of the exploration and exploitation of sandstone-type uraniumdeposits as they control the spatial distribution, porosity, the permeability and the sealing ability of sandstone and mudstone, and stacking patterns of strata configuration. Taking Dongsheng uraniumdeposits as an example, the application of base-level cycles to exploration and exploitation of sandstone uraniumdeposits was analyzed. It is suggested that favorable strata framework of sandstone ...
The Lander Quadrangle, Wyoming, was evaluated to a depth of 1500 m to identify environments and delineate areas that exhibit characteristics favorable for the the occurrence of uraniumdeposits. The evaluation used criteria established for the National Uranium Resources Evaluation program. The methods of surface investigations included evaluation of aerial radiometric and hydrogeochemical stream-sediment reconnaissance data, verification of some reported uranium occurrences, and general field geology with rock, water, and sediment sampling. The subsurface evaluation was accomplished through the use of 230 various oil-well logs. The results of this investigation identified three environments favorable for sandstone uraniumdeposits in Eocene fluvial sediments. These environments are within the Battle Spring and upper Fort Union Formations of the northern Great ...
The Lander Quadrangle, Wyoming, was evaluated to a depth of 1500 m to identify environments and delineate areas that exhibit characteristics favorable for the the occurrence of uraniumdeposits. The evaluation used criteria established for the National Uranium Resources Evaluation program. The methods of surface investigations included evaluation of aerial radiometric and hydrogeochemical stream-sediment reconnaissance data, verification of some reported uranium occurrences, and general field geology with rock, water, and sediment sampling. The subsurface evaluation was accomplished through the use of 230 various oil-well logs. The results of this investigation identified three environments favorable for sandstone uraniumdeposits in Eocene fluvial sediments. These environments are within the Battle Spring and upper Fort Union Formations of the northern Great ...
A synthesis of scientific knowledge about petroleum biodegradation linked to uranium mineralisation is firstly done. Then the genesis of Huemul Uranium ore deposit (Malargue Town, Mendoza Province) is discussed, where Uranium ore is linked only with one type of asphaltite (there are three other types) from an oil field close by. This asphaltite type would be an efficient natural geological barrier for Uranium migration and it could be linked to a particular kind of biodegradation. The authors think that the International Wonuc Conference would be a good opportunity to discuss a way for future investigations. (author)
In the present work, a rapid deposition anodic stripping voltammetry (ASV) for determination of uranium is presented. For this purpose, the uranyl hexacyanoferrate (K2UO2[Fe(CN)6]) is deposited electrochemically on a thin palladium-aluminum electrode (Pd-Al) from a UO22+ solution in the presence of K3Fe(CN)6. Then, the well stable (K2UO2[Fe(CN)6]) on the electrode was stripped by anodic differential pulse voltammetry for measuring the UO22+ ion concentration. The effect of operational parameters, including: concentration of K3Fe(CN)6, solution pH, deposition potential, and deposition time were studied. In optimum conditions, the calibration graph was linear in the concentration range 105-7 x 10-4 mol L-1 with a detection limit of 6.2 x 10-6 mol L-1. The influence of some concomitant ions in K2UO2[Fe(CN)6] formation was investigated. The proposed method was used for the rapid ...
A preliminary geologic investigation was conducted to determine if Triassic sedimentary rocks of the Sanford basin and Colon cross structure in North Carolina are favorable hosts for uraniumdeposits. Rocks of adjacent Carolina slate belt were also examined as a potential source of uranium. On the basis of favorability criteria for sandstone-type uraniumdeposits, and geologic and geophysical investigations of the study area, the most favorable sites for further investigation are (1) at the contacts between the Pekin and Cumnock and between the Pekin and Sanford Formations near the Colon cross structure and (2) at the base of the Jonesboro fault, which lies below the Sanford Formation, northwest of Sanford. The highly weathered granites southeast of the Jonesboro fault were a source of the detritus deposited on the cross structure and may have been a primary ...
The Grand Canyon Quadrangle (2/sup 0/), northwestern Arizona, was evaluated to identify environments and delineate areas favorable for the occurrence of uraniumdeposits. This was done using criteria developed for the National Uranium Resource Evaluation. General surface reconnaissance and geochemical sampling were carried out in all geologic environments within the quadrangle. Aerial radiometric and hydrochemical and stream-sediment reconnaissance surveys were performed, although results were not available in time for field checking. The results of this investigation indicate environments favorable for: channel-controlled, peneconcordant sandstone deposits in the Petrified Forest Member of the Chinle Formation in the north-central part of the quadrangle, vein-type deposits in collapse breccias in all areas underlain by the Redwall Limestone, and unconformity-related ...
Applying the theory of depositional system, the depositional facies and depositional systems of the Zhiluo Formation in Dongsheng area are systematically analysed, and the authors proposed that sediments of the Zhiluo Formation are of fluvial facies, and streams of the Zhiluo time experienced three evolution stages, namely: the early braided stream, the middle low sinuosity meandering stream and the late high sinuosity meandering stream. Based on features of paleoclimatic evolution, the Zhiluo Formation is divided into two lithological members. The lower lithological member consists of sediments of braided and low sinuosity meandering streams under humid-ward paleoclimatic conditions forming grey sedimentary formation. The upper member is composed of sediments of meandering streams under arid-hot paleoclimatic conditions representing complex-colored (mainly red) sedimentary formation. It is suggested that ...
ABSTRACT Shallow-lacustrine delta deposits of the Upper Triassic Yanchang Formation form the most important petroleum reservoir sandstone units in the Ordos Basin, China. Recent hydrocarbon exploration and outcrop studies demonstrated that shallow-lacustrine sand-rich deltas developed extensively along the gentle flanks and central part of the basin. The vertical succession of facies indicates that the Yanchang Formation records the entire lacustrine life cycle of the Late Triassic Ordos Basin. Four third-order transgressive-regressive cycles and two larger shallow-lacustrine deltaic cycles have been recognized. A process-based depositional model, derived in part from the modern Ganjiang delta in Poyang Lake, China, is used to infer the origins of the sand-rich lacustrine delta deposits. S...
In this activity, students will make a turbidity current. They will discover how fluids of differing densities interact with one another, learn some ways the densities of fluids can be changed and observe how density currents transport and deposit tremendous amounts of sediment in lakes and in the ocean. Additional options allow students to create and observe different kinds of density currents.
The application of airborne sensors for providing environmental assessment and monitoring of a test site in an open cast mining area that is part of a lignite deposit in central Germany is described. Hyperspectral remote sensing data from three different sensors were tested. The hyperspectral scanner data was suitable for classification of different sediments and vegetation types and the water chemistry of residual mining lakes. Summary form only. 1 tab.
Niger is the second poorest country in the world but it has natural resources underground in the form of uranium ores deposits. This uranium is currently mined by two companies incorporated under Nigerian law: Somair and Cominak, operated by the principal shareholder Areva (through its subsidiary Cogema). After a presentation of Somair and Cominak key figures, this document details the working conditions and radiological protection, the environmentally friendly operations, the production traceability, the local economic development, the strengthening of the health care system and the development of the infrastructure. (A.L.B.)
In Japan, the Ningyo-toge uraniumdeposit was discovered in 1955, and the Tono deposit in 1962. Geology of these mines is different from that of other metal mines developed in Japan. Therefore, it appeared that some changes were required in the usual mining methods applied to existing metal mines to mine uranium ore in these deposits. At the Ningyo-toge mine, effective methods were studied for mining the ore, such as the room and pillar method, long-wall method, slicing method, and the hydraulic method; as a result, it was determined that a modified long-wall method is the most useful and practicable for recovering uranium ore from this underground sedimentary deposit. Applicatons of in-place and microbiological leaching to these deposits are being studied to secure mine safety and decrease mine pollution. Since 1959, ...
Spent oxide fuels are reduced in a molten salt of CaCl[sub 2]-CaF[sub 2] to convert them into metals, then melted in an Fe-U bath disposed in an electrolytic refining vessel and brought into contact with molten Mg, to extract transuranium elements and rare earth elements contained in the Fe-U bath as metals in the molten Mg. Then molten Mg is removed and the residue is brought into contact with KCl-LiCl molten salt and electrolyzed using the Fe-U as an anode. Then, uranium is recovered by deposition on an iron cathode disposed in chloride electrolytes of the electrolytic refining vessel. Uranium and transuranium elements can be thus separated and, for example, depleted uranium for use in blanket fuels can be recovered easily. This can greatly reduce the temporary storage amount of depleted uranium, to eliminate requirement for a large-scaled facility used exclusively for storing ...
Spent oxide fuels are reduced in a molten salt of CaCl_2-CaF_2 to convert them into metals, then melted in an Fe-U bath disposed in an electrolytic refining vessel and brought into contact with molten Mg, to extract transuranium elements and rare earth elements contained in the Fe-U bath as metals in the molten Mg. Then molten Mg is removed and the residue is brought into contact with KCl-LiCl molten salt and electrolyzed using the Fe-U as an anode. Then, uranium is recovered by deposition on an iron cathode disposed in chloride electrolytes of the electrolytic refining vessel. Uranium and transuranium elements can be thus separated and, for example, depleted uranium for use in blanket fuels can be recovered easily. This can greatly reduce the temporary storage amount of depleted uranium, to eliminate requirement for a large-scaled facility used exclusively for storing ...
A series of branched alkylbenzene ranging from C15 to C19 with several isomers (2?5) at each carbon number were identified in sediments from the Dongsheng sedimentary uranium ore deposits, Ordos Basin, China. The distribution patterns of the branched alkylbenzenes show significant differences in the sample extracts. The branched alkylbenzenes from organic-rich argillites and coals range from C15 to C19 homologues, in which the C17 or C18 dominated. On the other hand, the C19 branched alkylbenzenes dominated in the sandstone/siltstone extracts. The obvious differences of the branched alkylbenzene distributions between the uranium-host sandstones/siltstones and the interbedded barren organic-rich mudstones/coals probably indicate their potential use as biological markers associated with part...
The US National Council on Radiation Protection and Measurements, in collaboration with the International Commission on Radiological Protection, has been developing a biokinetic and dosimetric model for radionuclide-contaminated wounds. The finalised model is described briefly in this paper, together with the scientific basis and application. The multicompartment model uses first-order linear biokinetics to describe the retention and clearance of a radionuclide deposited in a wound site using seven default retention categories. Examples using plutonium nitrate in colloidal form and uranium in metal fragments show the behaviour of the less soluble forms of radionuclides in wounds, in which long-term retention is predicted. Using uranium as an example, the wound model is coupled to a uranium International Commission on Radiological Protection systemic model to predict urinary excretion patterns for ...
Phosphoro-uraniferous deposit of Itataia is situated in Precambrian metamorphic terrains, into the litho-stratigraphic unit named Caico Complex. Regionally, the rocks are linearly folded, as a result of compressive tectonic that fits in the regmatic pattern. Rio Groairas' and Itatira's wrench faults form shearing couples in which the drag folds' climax are thrusting faults with axial plane dipping north. Uranium mineralization occurs into a phosphatic rock containing about 80% of collophane - 'collophanite - in association chiefly with marbles or feldsphatic rocks and gneisses. The ore (collophanite) occurs mainly as a stockwork, and it may be massive, (into big joints) or disseminated (impregnating the host rocks). Dark ore appears only in brecciated zones; it is richer in uranium content, but poorer in phosphorous. The highest grade ore is in a very fractured zone, associated to marbles. Supergene enrichment took place in ...
A broad range of persistent organic pollutants (POPs) and selected heavy metals has been analysed in sediment cores of North-East Germany. The pollutants analysed include polychlorinated dioxins and furans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), several pesticides (DDT, HCH, CBz) and its metabolites as well as selected heavy metals. The sediment cores were sampled at five locations, reflecting a range of anthropogenic influences and background contamination: Arkona Basin (AK) representing a remote marine site, Lake Bugsin (BS) a background location only with atmospheric deposition, Lake Quenz (QS) close to the industrial city of Brandenburg, Teltowkanal (TK) in the suburban-industrial zone of Berlin and Lake White (WS) in the centre of Berlin. The age of the lower part of the AK, BS and TK cores were dated at 100-150 years. Results of selected pollutants ...
At two locations in southern Lake Huron (U.S.A.), twelve 35.5-cm diameter cores of fine-grained sediments were taken for comparison of the vertical distribution of "2"1"0Pb and fallout "1"3"7Cs with the distribution of benthic macroinvertebrates, mainly oligochaete worms (Tubificidae) and the amphipod, Pontoporeia affinis. Locations were selected on the basis of "2"1"0Pb distributions measured a year earlier which indicated contrasting depths of mixing of surface sediments. At one location the activity of "2"1"0Pb is uniform down to about 6 cm and 95% of total invertebrates occur within this zone; at the other location the zone of constant activity is only 3 cm deep but 90% of the invertebrates occur within it. Comparison of published tubificid defecation rates with sediment accumulation rates based on "2"1"0Pb shows that oligochaetes alone can account for mixing in one case while the effects of amphipods may be required in the case of shallower mixing. If mixing ...
In one of the first uses of high Tc superconductors in an end-use product, Lake Shore Cryotronics and a Swiss lab have developed a liquid nitrogen level sensor using a high Tc thin film. The probe is manufactured using a seamless stainless steel tube with an yttrium-based zirconium oxide flame-sprayed on the tube. A plasma-sprayed superconductor compound is deposited on top of that. The probe is coated with a sealant that protects the superconducting film from the atmosphere. This manufacturing method has yielded an extremely durable product. Unaffected by ice formation and related mechanical problems, the superconducting level sensor can be kept in the dewar for long periods of time.
Different technological procedures used for the chemical mining of uranium differ for one thing with a level of the deposit exploitation and for another with the expenditures. It is necessary to find out the highest acceptable value of the costs per unit of production - limit unit costs. This criterion serves both for selection of the minable parts of deposit, and for determination of the exploitation level of the deposit parts. The paper describes a calculation of the costs and their decomposition into the fixed and variable costs. An evaluation of the different variants of the deposit exploitation is based on the variable costs, expressed in the dependence on the parameters of technological procedure. These parameters are either primary, e.g. density of the wells or dosage of reagents, or secondary, e.g. the uranium production. A relation between primary and ...
High-resolution sequence stratigraphy has been applied widely in the petroleum exploration and development, many achievements have been achieved. However, it is in the beginning stage that high-resolution sequence stratigraphy is applied to explore the sandstone-type uraniumdeposits in Erlian Basin. By applying principles of high-resolution sequence stratigraphy and taking typical boreholes as an example, sedimentary cycles of Saihan Formation, the ore-bearing formation in Baiyinwula area are divided and correlated through cross sections. One long-term cycle (LSC_1), two middle-term cycles (MSC_1, MSC_2) have been identified in this study. Based on this and combined with the mineralization character of sandstone uraniumdeposits in this area, it is presented that the interlayer oxidation zone is developed mainly in the rising hemicycle of MSC_1 and uranium ore bodies predominantly ...
The ore-hosting Yaojia Formation is composed of a set of braided stream medium-fine grained sediments. Guided by the basic theory of high-resolution sequence stratigraphy, and based on the core observation, the analysis of chemical composition of rocks, and data of natural potential logging and apparent resistivity logging, the authors have set up the high-resolution sequence stratigraphy framework of the ore-hosting Yaojia Formation, and discussed the relation of the stratigraphic structure of the middle cycle, as well as the paleotopography, the micro-facies to the formation of uraniumdeposit. (authors)
Uranium dendrites which were deposited at a solid cathode of an electrorefiner contained a certain amount of salts. These salts should be removed for the recovery of pure metal using a cathode processor. In the uraniumdeposits from the electrorefining process, there are actinide chlorides and rare earth chlorides in addition to uranium chloride in the LiCl-KCl eutectic salt. The evaporation behaviors of the actinides and rare earth chlorides in the salts should be investigated for the removal of salts in the deposits. Experiments on the salt evaporation of rare earth chlorides in a LiCl-KCl eutectic salt were carried out. Though the vapor pressures of the rare earth chlorides were lower than those of the LiCl and KCl, the rare earth chlorides were co-evaporized with the LiCl-KCl eutectic salt. The Hertz-Langmuir relation was applied for this evaporation, and ...
Multi-millennial climate changes were relatively minor over the mid-late Holocene in the British Isles, because orbitally forced insolation changes were smaller than those at higher latitudes. Centennial climate variability is thus likely to have exerted a greater influence on the environment and human society of the region. Proxy-climate records from the British Isles covering the last 4500years are assembled and re-evaluated with the aim of identifying centennial climate variability reflected by multi-proxy indicators. The proxies include bog oak populations, peatland surface wetness, flooding episodes from fluvial deposits, speleothem annual band width and oxygen isotopes, chironomids from lake sediments and sand and dune deposition. Most proxies reflect water balance rather than temper...
During the weekend of September 2--3, 1984, a part of the wooden spillway for Steed Pond gave way and the pond slowly drained. Consideration is being given to leaving Steed Pond dry. Steed Pond has accumulated some of the uranium discharged from 300 Area operations and past surveys have shown that the uranium concentration in the sediments ranges between 20 and 531 pCi/gm. The recently completed aerial survey of the exposed area of Steed Pond showed that the uranium was widely spread in the sediments of Steed Pond. Until ground cover is established over the exposed pond sediments, they will be subject to erosion. As much as 90 tons of sediment could be eroded from the exposed sediments in Steed Pond the first year, but the erosion could be reduced to 5--15 tons by establishing a ground cover such as rye grass. Only about 40% of the eroded sediment would be delivered to Upper Three Runs Creek, because most of the eroded ...
A general criterion has been suggested for deep geological repositories containing spent fuel - the repositories should impose no greater radiological risk than due to naturally occurring uraniumdeposits. The following analysis investigates the rationale of that suggestion and determines whether current expectations of spent-fuel repository performance are consistent with such a criterion. In this study, reference spent-fuel repositories were compared to natural uranium-ore deposits. Comparisons were based on intrinsic characteristics, such as radionuclide inventory, depth, proximity to aquifers, and regional distribution, and actual and potential radiological consequences that are now occurring from some ore deposits and that may eventually occur from repositories and other ore deposits. The comparison results show that the repositories are quite comparable to ...
Urmia Lake has been designated as an international park by the United Nations. The lake occupies a 5700 km2 depression in northwestern Iran. Thirteen permanent rivers flow into the lake. Water level...Full Text Available
This study was carried out mainly to produce uranium trioxide (UO_3), with the standard of commercial specifications from rock phosphate deposits in eastern part of Nuba mountains, south Kurdufan state. A simplified hydrometallurgical procedure has been adopted for production of yellow cake from the ore. Elemental analysis has shown that the ore is rich in Ca and deficient in elements of potential interest such as Fe, Cu and Zn. Uranium content in ore, phosphoric acid and purified yellow cake (UO_3) obtained with different precipitants was analyzed using alpha-spectrometry. On the average, the activity concentration of uranium in ore corresponds to 82 #+-# 24 ppm (0.10%). From the data of pregnant liquor, it was observed that the addition of KCIO_3 as an oxidant improves the dissolution of uranium from the ore by almost 20%. Data has also indicated that the yellow cake purified by ...
Mining lakes are of a world-wide challenging problem caused by the well known acid mine drainage (AMD) and the dynamics of it. In the past, there was no possibility to monitor these mining lakes for an investigation of chemical and biological parameters. But, in general, remote sensing methods are suitable for a monitoring of natural lakes, and now, at the first time, those can be used for a distinction of acid mining lakes in central Germany into different types. In acid mining lakes unusual absorption and scattering properties exist due to the water constituents which are quite different in their optical properties to those of natural lakes. The artificial lakes show high concentrations of metal ions and compounds. This fact was used to discriminate the mining lakes into initial stage, early stage, transitional state ...
Concentrations of tritium in environmental waters (precipitation, rivers, lakes, tap water) have been determined using electrolytic enrichment and liquid scintillation counting. In waters of big rivers (the Vistula and the Odra rivers), lakes and tap water the annual average concentrations were similar to each other being from 1.4 to 1.9 Bq x dm"-"3. These concentrations were similar to those in the precipitation in which they ranged from 1.7 to 2.2 Bq x dm"-"3. The lowest tritium concentrations were found in waters of the Seashore Region rivers (average for 1994-1999 was 1.1 Bq x dm"-"3). The tritium concentrations in surface waters and in precipitation are still higher than that of natural level. The data obtained show that tritium concentration in the water of rivers might depend on the size of drainage area. The observed seasonal variations of tritium concentration in the precipitation collected in Warsaw and at the Mount Sniezka indicate ...
We report biological changes at several UK Acid Waters Monitoring Network lakes and streams that are spatially consistent with the recovery of water chemistry induced by reductions in acid deposition. These include trends toward more acid-sensitive epilithic diatom and macroinvertebrate assemblages, an increasing proportional abundance of macroinvertebrate predators, an increasing occurrence of acid-sensitive aquatic macrophyte species, and the recent appearance of juvenile (<1 year old) brown trout in some of the more acidic flowing waters. Changes are often shown to be directly linked to annual variations in acidity. Although indicative of biological improvement in response to improving water chemistry, 'recovery' in most cases is modest and very gradual. While specific ecological recovery endpoints are uncertain, it is likely that physical and biotic interactions are influencing the rate of recovery of certain groups of organisms at ...
The improving uranium extraction efficiency of yellow cake production from shale deposit by acid pugging and curing with D263B resin adsorption is described in this paper. The analysis and examination show that the composition of uranium minerals in one of uranium ores is very complex, which directly influence the extraction efficiency of uranium and processing technology. Conventional experimental results indicate that uranium leaching efficiency is changed between 50?60% by conventional agitation method. In this case, acid pugging and curing experiments are employed in order to improving the extraction efficiency. A series of acid pugging and curing experiments are carried out to get parameters for heap leaching in pilot plant experiment. The experiment results by acid pugging and curing technology showed that uranium leaching efficiency ...
The ability of residual biomass from the thermotolerant ethanol-producing yeast strain Kluyveromyces marxianus IMB3 to function as a biosorbent for uranium has been examined. It was found that the biomass had an observed maximum biosorption capacity of 120 mg U/g dry weight of biomass. The calculated value for the biosorption maximum, obtained by fitting the data to the Langmuir model was found to be 130 mg U/g dry weight biomass. Maximum biosorption capacities were examined at a number of temperatures and both the observed and calculated values obtained for those capacities increased with increasing temperature. Decreasing the pH of the biosorbate solution resulted in a decrease in uptake capacity. When biosorption reactions were carried out using sea-water as the diluent it was found that the maximum biosorption capacity of the biomass increased significantly. Using transmission electron microscopy, uranium crystals were shown to be ...
Thorium-230, together with "2"3"8U and "2"2"6Ra, was determined (mainly by #gamma#-spectrometry) in samples from the waste piles at Borst and Jazbec in the vicinity of the former uranium mine at Zirovski vrh, Slovenia. Activity (and in the case of uranium, also mass) balances for these nuclides were constructed for the overall operation of the mine and yellow cake plant, using experimental data and known data on ore and uranium production, and nuclide emissions to the environment. All the "2"2"6Ra resulting from ore exploitation is presently contained in the Borst tailings pile. However, because of the very high content of "2"3"0Th in red mud deposited at Jazbec, where 60% of this nuclide is found, the majority of "2"2"6Ra will be found at the Jazbec pile in the future, due to its ingrowth from "2"3"0Th over the next few thousand years. (Author).
The Jaduguda U (?Cu?Fe) deposit in the Singhbhum shear zone has been the most productive uraniumdeposit in India. Pyrite occurs as disseminated grains or in sulphide stringers and veins in the ore zone. Veins, both concordant and discordant to the pervasive foliation, are mineralogically either simple comprising pyrite ? chalcopyrite or complex comprising pyrite + chalcopyrite + pentlandite + millerite. Nickel-sulphide minerals, though fairly common in concordant veins, are very rare in the discordant veins. Pyrite in Ni-sulphide association is commonly replaced by pentlandite at the grain boundary or along micro-cracks. Based on concentrations of Co and Ni, pyrite is classified as: type-A ? high Co (up to 30800?ppm), no/low Ni; type-B ? moderate Co (up to 16500?ppm) and moderate to high ...
Understanding the link between the Sun and climate is vital in the current incidence of global climate change, and 10Be in natural archives constitutes an excellent tracer for this purpose. As cosmic rays enter the atmosphere, cosmogenic isotopes like 10Be and 14C are formed. Variations in solar activity modulate the amount of incoming cosmic rays, and thereby cosmogenic isotope production. Atmospherically produced 10Be enters natural archives such as sediments and glaciers by wet and dry deposition within about a year of production. 10Be from natural archives therefore provides information on past solar activity, and because these archives also contain climate information, solar activity and climate can be linked. One remaining question is to what degree 10Be in natural archives reflects production, and to what extent the local and regional environment overprints the production signal. To explore this, 10Be was measured at annual resolution over the last 600 years ...
The first member of the Qingshankou Formation recovered by CCSD-SK-Is borehole (China Cretaceous Continental Scientific Drilling-SongkeI-the south borehole) is 81.41 m long, and the recovery of cores is 100%. The age of the member is approximately Turonian. The sequence and process of lithology-lithofacies and cyclic stratigraphy were revealed by a detailed core description. 6 rock types (mudstone, dolomite, marl, limestone, ostracode limestone, and volcanic ash) comprise the sedimentary strata. Deposition occurred in a deep lake, including 6 sedimentary microfacies: mudstone, sandy turbidite, dolomite, marl, limestone, and volcanic ash microfacies. The first member of the Qingshankou Formation represents 81 meter-scale cycles (sixth-order cycle), 25 fifth-order cycles, 6 fourth-order cycl...
By applying the high-resolution sequence stratigraphy, the different sub-divisions of base-level cycles of Qingtujing Formation, Middle Jurassic in Chaoshui Basin are analyzed in detail. 23 short, 3 middle and 1 long base-level cycles are recognized. On the above basis, the corresponding frameworks of high-resolution sequence stratigraphy have been established in northern and southern sub-basins respectively, and the detailed sedimentary facies of MSC_1_-_3 and the special distribution of Qintujing Formation are discussed. It is pointed out that MSC_2 is the most favorable layer for the localization of sandstone-type uraniumdeposits. (authors)
Asphalt emulsions were evaluated as a means to immobilize radiological contaminants deposited on urban surfaces after a dirty bomb attack. Contaminated surfaces would be sprayed with thin coatings of asphalt emulsion to encapsulate the radioactive particles until the site can be safely remediated. This research investigated applications of an asphalt emulsion (Topein C, Encapco Technologies, LLC, Napa, CA) to treat (zero-valent) iron, lead, and uranium powders on various building material surfaces. Initial studies found that some of the building materials (limestone, concrete, and metal) reacted with the emulsion producing gas bubbles, which formed 0.001 to 1 cm vesicles in the cured asphalt emulsion. These vesicles, however, did not expose the building material surface, and the reaction a...
This report presents the results of an assessment of uranium in situ leach mining costs through the application of process engineering and discounted cash flow analysis procedures. A computerized costing technique was developed to facilitate rapid cost analyses. Applications of the cost model will generate mine life capital and operating costs as well as solve for economic production cost per pound U/sub 3/O/sub 8/. Conversely, rate of return may be determined subject to a known selling price. The data bases of the cost model were designed to reflect variations in Texas versus Wyoming site applications. The results of applying the model under numerous ore deposit, operating, well field, and extraction plant conditions for Texas and Wyoming are summarized in the report. Sensitivity analysis of changes in key project parameters have also been tested and are included.
The study examines the question of whether or not civilian marketing practices and principles can be applied in the military care setting. Using the NRMC Great Lakes as a basis, the answer is yes--consumers of military medical care are ready to be the rec...
BackgroundLake Tanganyika (LT) is the oldest of the African Rift Lakes and is one of the richest freshwater ecosystems on Earth, with high levels of faunal diversity and endemism....Full Text Available
On the west flank of the Wind River Mountains, Wyoming, are several large lakes occupying glacially scoured depressions dammed by terminal moraines. Fremont, Willow, and New Fork Lakes, having maximal...Full Text Available
Full text: Recent geoarchaeological research in the Erzurum district, north-eastern Anatolia, has revealed an abundance of obsidian at numerous neolithic and Bronze Age sites. Geochemical characterisation using neutron activation analysis indicates that the obsidian was obtained from several sources that are chemically distinct from the major sources already known from Central Anatolia an the Lake Van area. Multiple sources are represented in the samples collected from at least two of the sites, namely the sites of Sos and Pulur. The primary source of some of the obsidian utilised at the site of Sos has been located in the volcanic sequence outcropping tot he north-west of Pasinler. Field survey however has shown that the alluvial deposits along the main rivers and some of their tributaries were the main sources of the obsidian utilised at the sites near Erzurum. Trade or exchange of obsidian with sites outside the Erzurum area seems to have ...
Measurements have been made of radon ("2"2"2Rn), release from diverse quaternary samples collected from different sediment deposits in the Errachidia and Beni-Mellal areas (Morocco). The radon diffusion coefficient as one of some important parameters of radon transport in the soil has been measured using solid state nuclear track detectors (SSNTD). Radon #alpha#-activity, uranium content and radon exhalation rate have been determined in the studied samples. Uranium concentrations were found to vary from 0.14 to 9.52 ppm whereas the radon exhalation rate varied from 0.003 to 0.145 Bq x m"-"2 x h"-"1. A positive correlation has been found between radon exhalation rate and uranium content in the studied samples. The average radon diffusion coefficients were found to vary from (1.26 #+-# 0.09) x 10"-"6 m"2 x s"-"1 to (4.3 #+-# 0.36) x 10"-"6 m"2 x s"-"1. Furthermore, the correlation between "2"2"2Rn ...
The main objective of the pilot Coal Compilation Project is to provide coal resource maps to stimulate and support industry exploration programs, and assist government in matters of resource management. An essential feature of the program is the use of cost effective Geoscience Information System (GSIS) technology that allows the database and various thematic maps to be analyzed, updated, and displayed with complete flexibility at any scale. This report describes the main features (geology, exploration history, coal occurrences, coal quality etc.) of the study area, map sheet NTS 83F/5 (Entrance), and includes a copy of the 1:50,000 scale map produced. The study area is located in west-central Alberta and contains coal measures deposited within thick successions of sandstones, siltstones, shales and conglomerates. These coal-bearing sequences are part of the Lower Cretaceous Luscar Group, Upper Cretaceous Brazeau Formation and Paleocene Coalspur Formation. The ...
Several organophosphate and organochlorine compounds, including pesticides commonly found in the Great Lakes basin, have the potential to induce immunotoxicity. Because of biomagnification and accumulation...Full Text Available
This study was carried out mainly to produce uranium trioxide (UO_3), matching standard commercial specification from rock phosphate deposits in Uro and Kurun at eastern part of the Nuba Mountains. A simplified hydrometallurgical procedure has been adopted for production of yellow cake from the ore. The powdered ore sample was leached with concentrated H_2SO_4 acid with and without addition of KCIO_3 as an oxidant. The crude yellow cake was precipitated from the resulting green solution of phosphoric acid as Na_2U_2O_7 and (NH_4)_2U_2O_7 and subsequently purified by TBP extraction (tributylphosphate) and hydrogen peroxide as UO_4.2H_2O. TBP purified product was dried and calcined to UO_3 whereas UO_4.2H-2O was dried and reduced to UO_3 by Na_2S_2O_3. Prior to precipitation of crude yellow cake, Fe in the phosphoric acid solution was precipitated using magnesia. Elemental analysis has shown that the ore is rich in Ca and deficient in elements of ...
The release rate of a nuclide from a reactor or a radioactive waste disposal plant at the accident is not steady, but varies with time. The various parameters of a nuclide migration into environment vary also day after day, or with the seasons. In such cases, dynamic behavior of the nuclide in the environment must be taken into consideration. It is difficult for a mathematical model to involve all of mechanisms for the nuclide migration. The environment for evaluation of doses are usually divided into some of compartments in which a nuclide concentration is uniform. Time variations of the nuclide concentration in the compartment are described in simultaneous differential equations. The nuclide concentration can be solved as a time function, and the radiation doses, therefore, can be estimated as a time function. Generic analysis code for dynamic compartment model (GACOM) is developed for the nuclide migration and the evaluation of doses in terrestrial biosphere. The code contains many ...
In acute intoxication, uranium (U) not only inhibits bone formation but its excretion in urine also causes renal damage. The former effect is ameliorated by tetracycline (TC), probably due to its chelation property, which might also prevent U deposition in bone. Chemical determination of U incorporated in bone and a histological study of the kidneys were performed on animals injected with U and then treated with TC. The results showed that TC was unable to prevent the binding of U to bone while it exacerbated U-induced renal damage.
High-pressure waterjet equipment is now technically and economically viable and commercially available for the following mining and construction applications: (1) drilling soft to medium-hard rock; (2) slotting, discing, chambering, and reaming in all types of rock. However, additional field experience is needed to prepare detailed economic evaluations. Extensive development of new explosives techniques and blasting methods will be required to take full advantage of the unique waterjet hole slotting, discing, and chambering capabilities.
The Uinta Basin is an important hydrocarbon producing area, with extensive resources of hydrocarbon, bitumen, and fossil fuels. Gilsonite, tar sands, oil shale and coal are found in abundance with the cretaceous and Tertiary sedimentary rocks. The 25 papers include discussion on: leasing; thermal maturity of rocks and hydrocarbon deposits; influence of source rock type, thermal maturity and migration on composition and distribution of the natural gas; drilling; geology; structural evolution of gilsonite dykes; reclamation of coal mines; oil shale resources; and uranium mining.
Lake Erie, the southernmost of the Laurentian Great Lakes, is narrow and relatively shallow in comparison to other Great Lakes. The lake experiences extreme water level fluctuations and storm energy restricts the development of wetlands to protected areas within embayments, lagoons, or behind barriers. However, coastal marshes of western Lake Erie fringe the shorelines of Michigan, Ohio, and Ontario and encompass an area of 268 km/sup 2/. This publication reviews the ecological data and information on the wetlands of Lake Erie, which are some of the more productive areas in the Great Lakes ecosystem. The geologic history of the Lake Erie leading to the development of wetlands, the present environment, and present wetland distribution are presented as background in the opening chapters. Biological information available ...
In accordance with Public Law 95-217, Section 314 (the 'Clean Lakes' section of the 1977 Amendments to the Federal Water Pollution Control Act), the Massachusetts Division of Water Pollution Control developed a lake classification program based upon the trophic condition of all publicly owned freshwater lakes and ponds in the Commonwealth. This publication, produced and updated on an annual basis since 1976, is the result of that program.
The authors have interpreted 1,400 km of industry and government multichannel seismic reflection data from eastern Lake Superior. Seismic sequences have been identified by using reflection character and reflector terminations and truncations. This framework, coupled with outcrop information, has allowed them to assign lithologic units to some of these reflectors and reconstruct the timing and geometry of structures within the basin. The authors have mapped the Base Jacobsville-Bayfield Group/Top oronto Group, Base oronto Group/Top Keweenawan volcanics, and Basement as well as several reflectors internal to these groups. Integration of gravity and magnetic data with the seismic grid permits regional mapping of faults and folds between seismic lines. In the eastern part of the basin, high-angle basement-involved reverse faults, such as the southeastern combination of the Keweenaw fault, trend NNW-SSE, while broad folds trend E-W. The Keweenaw fault is a complex ...
The Upper Jurassic Hith Anhydrite is a major hydrocarbon seal in the Arabian Gulf region. Outcrops, core samples from the subsurface, and the literature indicate that the Hith Formation is composed mainly of anhydrite. In most locations where a section of the Hith Formation has been measured, this unit contains less than 20% carbonate much of which is in the form of thin laminations. This lack of carbonate, locally thick layers of salt, and the predominance of anhydrite favor a playa for the setting in which this sediment was accumulated. In fact, much of the Hith has the sedimentary characteristics of the Holocene Lake MacLeod playa of Western Australia, which is dominated by layers of gypsum and halite (what little carbonate that occurs is found in layers at the base of the section). Locally the Hith appears to have accumulated in a sabkha setting, particularly toward central Abu Dhabi where it pinches out into shallow-water, and peritidal carbonate. This sabkha ...
The main purpose of the pilot Coal Compilation Project is to provide coal resource maps to stimulate and support industry exploration programs, and assist government in matters of resource management. An essential feature of the program is the use of cost effective Geoscience Information System (GSIS) technology that allows the database and various thematic maps to be analyzed, updated, and displayed with complete flexibility at any scale. This report describes the main features (geology, resource management, coal occurrences, etc.) of the study area, mapsheet NTS 83E/15 (Pierre Greys Lakes), and includes a copy of the 1:50,000 scale map produced. The study area is located in west-central Alberta and contains coal measures deposited amid thick successions of sandstones, siltstones, shales and conglomerates. These coal-bearing sequences are part of the Lower Cretaceous Luscar Group, Upper Cretaceous Brazeau Formation and Paleocene Coalspur ...
This interim technical report presented a summary of results obtained from Pit Lake models developed from different simulation models. The models were used to predict stratification in a hypothetical Pit Lake. Predictions were used to assess the hydrodynamic similarities and differences between the 2 models and to determine if the models would produce similar stratification profiles for the Pit Lakes to previous models. Results showed that the models produced similar results for both temperatures and salinities. The main difference between the RMA10 and CE-QUAL-W2 model used in a previous study was found to be run time. A sensitivity analysis of the RMA10 and CE-QUAL-W2 model predictions was completed to assess the effects of segmentation; time step; lake surface area; lake orientation; and model coefficients or parameters. Results showed that the selected time step and model ...
Samples of Parmelia sulcata and Xanthoria parietina from different biotopes have been analysed for elements of the series of uranium 238 and thorium 232. These species have been used as bio-monitors in different cases : urban areas, coal fired power plant, tip for uranium-mining residues. The concentration of most of these elements in lichens is decreasing as follows: radium waste-disposal site > area with uranium-rich soil > urban area > rural area. Road traffic was not found to increase notably the presence of radioactive lead in the environment. The two foliose lichens seem to have a comparable concentration ability, but Parmelia sulcata appeared to be more reliable. Some of the elements under investigation could be particularly problematic from a sanitary point of view: the intake limits in case of inhalation are very low and the atmospheric deposition is not negligible; this is ...
This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator cleaning demonstrations and provides details of the cleaning ...
This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator cleaning demonstrations and provides details of the cleaning operation for ...
The primary purpose of the pilot Coal Compilation Project is to provide coal resource maps to stimulate and support industry exploration programs and to assist government in matters of resource management. An essential feature of the program is the use of cost effective Geoscience Information System (GSIS) technology that allows the database and various thematic maps to be analysed, updated and displayed with complete flexibility at any scale. This report describes the main features (geology, resource management, exploration history, coal occurrences etc.) of the study area, mapsheet NTS 83E/9 (Moberly Creek), and includes a copy of the 1:50,000 scale map produced. The study area is located in West-central Alberta and contains coal measures deposited amid thick successions of sandstones, siltstones, shales and conglomerates. These coal-bearing sequences are part of the Luscar Group, Upper Cretaceous Brazeau Formation and Paleocene Coalspur Formations. Coal seams ...
Study of glacial geology, stream drainage, bedrock topography, and subsurface structure maps in Isabella, Midland, Arenac, Gladwin, Clare, Ogemaw, Iosco, Mecosta, and Montcalm counties in Michigan revealed distinct correlations between patterns and types of glacial deposits and subsurface structures. Anticlinal structures associated with the Mt. Pleasant, North Buckeye, and South Buckeye, Hamilton, Deep River, Clayton, Logan, Six Lakes, and West Branch oil and gas fields occur along areas where northeast-trending glacial moraines and truncated, attenuated, or deviated. Furthermore, these anticlinal structures are associated with lacustrine sands and gravels and glacial outwash deposits nearly surrounded by glacial tills or lacustrine sands and clays. All of the anticlinal structures are associated with bedrock topography highs and alignment of streams parallel to the trends of the structures. Comparison of images of ...
In conducting aircraft surveys for uranium, it is found that temperature inversions can give spurious results because they promote accumulation of radon gas in the atmosphere. The "2"1"4Bi (daughter product of radon) gamma-rays detected from the atmosphere-borne radon are difficult to separate from the "2"1"4Bi gamma-rays originating from the ground, and providing a signature for uraniumdeposits. The purpose of the present study was to examine the feasibility of making remote temperature soundings of the atmosphere below a low-flying aircraft (140 m or less above ground) by the inversion of radiance measurements taken in the 15-micron carbon dioxide absorption band. Such measurements would identify those temperature inversion conditions possibly leading to an unacceptably large background of gamma-rays from the atmospheric radon. Thus, the incidence of spurious aerial survey data could be greatly reduced. An atmospheric ...
The Median Tectonic Zone (MTZ) of New Zealand is a generally north trending belt of Mesozoic subduction related I-type plutonic, volcanic, and sedimentary rocks in South Island and Stewart Island that separates Permian strata of the Eastern Province Brook Street Terrane from lower to mid Gondwana margin assemblages of the Western Province. High precision isotope dilution U/Pb ages of zircons from 30 rocks are reported. Pre-digestion leaching of zircon in hydrofluoric acid yielded significantly more concordant residues by removing common Pb and dissolving more soluble high-U domains that have been more affected by relatively recent Pb loss. The results show that MTZ magmatism ranges in age from at least Early Triassic to Early Cretaceous (247-131 Ma), with a pronounced gap in the Middle Jurassic. Triassic plutons tend to occur on the eastern side of the MTZ, and they intrude volcanic/sedimentary sequences of the MTZ in Nelson and eastern Fiordland. These sequences are in turn intruded ...
The studied coal bearing series has a parallel origin. The following facial complexes are isolated in its composition: lakes free of vegetation without coal interlayers; overgrown lakes of their margins which are poor in coals; swampy lakes, whose peat beds formed coal layers of shallow or moderate depth; channel sediments without coal layers and swamps from between channel spaces which created thick coal strata of high quality for which, however, a strong changeability in thickness is intrinsic. The coal strata are normally split towards the central parts of the lake basins and river channels. The coal presence of the suite is reduced along the section which is associated with the replacement of the lake swamp conditions of sedimentation by lake river conditions. A paleotectonic analysis established that the distribution of the zones richest in coal was ...
A common break was recognized in four Lake Superior strandplain sequences using geomorphic and sedimentologic characteristics. Strandplains were divided into lakeward and landward sets of beach ridges using aerial photographs and topographic surveys to identify similar surficial features and core data to identify similar subsurface features. Cross-strandplain, elevation-trend changes from a lowering towards the lake in the landward set of beach ridges to a rise or reduction of slope towards the lake in the lakeward set of beach ridges indicates that the break is associated with an outlet change for Lake Superior. Correlation of this break between study sites and age model results for the strandplain sequences suggest that the outlet change occurred sometime after about 2,400 calendar years...
This paper presents a study on Manasbal lake, which is one of the high altitude lakes in the Kashmir Valley, India. Eighteen water samples were analysed for major ions and trace elements to assess the variability of water quality of the lake for various purposes. Geostatistics, the theory of regionalized variables, was then used to enhance the dataset and estimate some missing spatial values. Results indicated that the concentration of major ions in the water samples in winter was higher than in summer. The scatter diagrams suggested the dominance of alkaline earths over the alkali elements. Three types of water were identified in the lake that are referred to as Ca?HCO3, Mg?HCO3 and hybrid types. The lake water was found to be controlled by rock?water interaction with carbonate lithology ...
Since high resolution sequence stratigraphy was introduced into China by DENG Hong-wen in 1995, it has been experienced two development stages in China which are the beginning stage of theory research and development of theory research and application, and the stage of theoretical maturity and widely application that is going into. It is proved by practices that high resolution sequence stratigraphy plays more and more important roles in the exploration and development of oil and gas in Chinese continental oil-bearing basin and the research field spreads to the exploration of coal mine, uranium mine and other strata deposits. However, the theory of high resolution sequence stratigraphy still has some shortages, it should be improved in many aspects. The authors point out that high resolution sequence stratigraphy should be characterized quantitatively and modelized by computer techniques. (authors)
It has been shown that not only there are abundant oil, gas, coal, coal-bed gas, groundwater and giant uraniumdeposits but also there are abundant oil shale resources in Ordos basin. It has been shown also that the thickness of oil shale is, usually, 4-36m, oil-bearing 1.5%-13.7%, caloric value 1.66-20.98MJ/kg. The resource amount of oil shale with burial depth less than 2000 m is over 2000x108t (334). Within it, confirmed reserve is about 1x108t (121). Not only huge economic benefit but also precious experience in developing oil shale may be obtained in Ordos basin.
The optimizing criterion is assumed to be the maximum net present value of the project. The following summarizes the significant conclusions. (1) Over a large range of discount rates, mining and milling of the mineral deposit at a constant cutoff grade and a constant production rate consistently results in smaller annual discounted cash flows than the optimal schedule determined by the dynamic programming model (dpm) where the cutoff grade and mining rate are allowed to vary in response to fluctuating product price. (2) With an increasing discount rate, under the dpm the annual discounted cash flows decrease at a slower rate than if the mineral inventory is mined and milled at a constant cutoff grade and a constant production rate. (3) Cuttoff grade increases only where higher equity ore is available. Thus, to maintain the mill feed requirement, the mining rate also increases. (4) Not withstanding an anamolous mineral deposit of high quality, ...
and streambed sediment samples 2-6. Graphs showing: 2. Cesium-137 profile in HOE core 3. PAH trends in Lake Houston cores 4. DDE trends in Lake Houston cores 5. Trends in six trace...
The ice cover in high mountain lakes breaks up and disappears in about an hour, in part because it has been divided into fragile vertical spindles, which are individual crystals. Contributing to this...Full Text Available
BackgroundRasbora tawarensis is an endemic freshwater fish in Lake Laut Tawar, Aceh Province, Indonesia. Unfortunately, its status is regarded as critical endangered...Full Text Available
The fauna of ancient lakes frequently contains taxa with highly derived morphologies that resulted from in situ radiation of lacustrine lineages with high antiquity. We employed a molecular...Full Text Available
... 03, 2001 | Rate It Lake Superior Streams http://www.lakesuperiorstreams.org/ (1 vote) interactively examine real-time water quality data from 5 ...north shore Lake Superior trout streams and learn about other streams in the region, how they \\
Cholera outbreaks continue to occur regularly in Africa. Cholera has been associated with proximity to lakes in East Africa, and Vibrio cholerae has been found experimentally to concentrate...Full Text Available
Progress is reported on: radon barrier systems for uranium mill tailings; liner evaluation for uranium mill tailings; revegetation/rock cover for stabilization of inactive U-tailings sites; and application of long-term chemical biobarriers for uranium tailings.
A discussion is given of uranium as an energy source in The Australian economy. Figures and predictions are presented on the world supply-demand position and also figures are given on the added value that can be achieved by the processing of uranium. Conclusions are drawn about Australia's future policy with regard to uranium (R.L.).
The Sulphur Bank Mercury Mine (SBMM) is a 65 ha site located on the eastern shore of the Oaks Arm of Clear Lake, Lake County, California. Between 1864 and 1957, SBMM was the site of underground and open pit mining operations for S and Hg, coinciding with past and present hot spr...
... The short residence time ensures that no temperature increase occurs. The pattern of entrainment, along with natural currents results in oxygenation of the entire hypolimnion. Figure 4 is a simplified schematic of the Lake LungTM. Built in circulators allow the lake manager to adjust the depth of the epilimnion, and to elect whether or not to destratify the lake to prolong the spring and autumn turnover. ...
A model has been developed to predict the chemical composition of lakes that form in pyrite-bearing open-pit mines. Pyrite oxidation in wall rock releases sulfuric acid and metals, which mix with ground waters in the lake. Aqueous metal concentrations are calculated using MINTEQA2.
The development of the spatial N export and retention model N{sub E}XRET for large river basins is presented, utilizing remote-sensing-based land use and forest classification. Export coefficients describing the contribution from agriculture, forestry and peat harvesting were estimated based on empirical studies. Representativeness of forest treatment coefficients have been evaluated by use of data from a small, well-documented test catchment. Simulation results from the application of the model to the Oulujoki river basin (22,840 km{sup 2} ) are discussed. Model estimated N fluxes were compared with measured N fluxes in separate points of the river basin. Based on source apportionment, agriculture contributes 17% of the total export, varying between 8% in the uppermost subbasin and 38% in the lowermost subbasin close to the sea. Forestry contributes almost as much, 16%, with less pronounced variation (11-24%) between the different subbasins. In the separate subbasins, 7-37% of the ...
The Ordos Basin of north-central China is well known for vast energy resources. This nonmarine interior basin developed on the North China-Korean platform following the Late Triassic Indochina orogeny and, for a time, contained a large freshwater lake prior to being uplifted into its present form at the close of the Mesozoic. Lower to Middle Jurassic coal occurs in the fluviolacustrine Yan'an Formation along the southern margin of the basin in the Huanglong coalfield. In the northeast part of the field, the formation ranges from 0 to 180 m in thickness and is divided into five fining-upward members, each representing a regressive-transgressive lacustrine cycle. Low-sulfur, high-volatile bituminous coal is complexly distributed in the lowest member of the Yan'an Formation. Deposition of this member was influenced by two tectonic events that controlled coal occurrence. First, regional uplifts were produced by the Late Triassic ...
This study resumes the discovery of an excess of actinium 227 found around by EL4 nuclear reactor actually in dismantling. The search for the origin of this excess revealed a real inquiry of investigation during three years. Because a nuclear reactor existed in this area a particular attention will have concerned this region. The doubt became the line of conduct to find the answer to the human or natural origin of this excess. Finally and against any evidence, it appears that the origin of this phenomenon was natural, consequence of the particular local geology. The detail of the different investigations is given: search of a possible correlation with the composition of elevations constituent of lanes, search (and underlining) of new sites in the surroundings of the Rusquec pond and the Plouenez station, study of the atmospheric deposits under winds of the nuclear power plant and in the east direction, search of a possible relationship with the gaseous effluents of ...
Numbers of wintering sea ducks, including buffleheads (Bucephala albeola; BUFF), common goldeneyes (Bucephala clangula; COGO), and long-tailed ducks (Clangula hyemalis; LTDU), increased substantially at Lake Ontario after Dreissenid mussels (Dreissena bugensis and D. polymorpha) colonized the Great Lakes. Invertebrates, including Dreissenid mussels, are major diving duck prey items that can transfer some trace elements, such as selenium (Se) to higher trophic levels. Se can be problematic for waterfowl and it often has been detected at elevated levels in organisms using the Great Lakes. There are, however, few data on hepatic Se concentrations in sea ducks, particularly during the winter at Lake Ontario. In this study, we evaluated interspecific differences and temporal trends in hepatic S...
Pit lakes form when open-pit mining operations are discontinued and dewatering ceases. The increase in open-pit metal mining since the 1970s will lead to the formation of numerous pit lakes over the next 50 years. Many of these lakes will develop acid sulfate conditions with high levels of dissolved metals. Approaches to remediation of these conditions that have been recommended include the addition of lime or other alkaline materials and the stimulation of sulfate-reducing bacteria. However, prevention rather than remediation is probably the preferable approach. Measures to prevent oxidation of mining waste and wall rocks, including measures to fill pits quickly with water, to inhibit the activity of acidophilic sulfur-oxidizing bacteria, and to promote anoxic conditions at the lake bottoms may minimize the formation of acids and dissolved metals. (orig.)
Many mines and processing facilities are in remote, difficult to access areas, or are in areas where access is limited or restricted for national reasons. In a joint project with Canada Centre for Remote Sensing, the Canadian Safeguards Support Program is investigating utility of multi- and hyperspectral remote sensing for remotely inspecting such site. With a view to eventually using the hyperspectral satellite data now coming available, airborne data over uranium and copper mine tailings and uranium processing facilities in northern Canada were acquired. The objective of this work is to demonstrate that multispectral and hyperspectral data can provide complementary and supplementary information to high-resolution panchromatic imagery for the following safeguards applications: Inspection aids (up-to-date maps of remote locations), change detection, evaluation of member state declarations, monitoring of reactor, mining and processing facility ...
The lakes formed in the Amazon floodplain play a key role in sustaining the highest populational density in the Amazon Basin because of its high primary productivity. The water volume in these lakes vary greatly during the year and possible water sources are the feeding river during high water state of the hydrographs and local inputs from its drainage basin. As these sources are chemically distinct, to understand the nutrient dynamics in these lakes, it is very important to know the relative water contribution of different water sources. In this paper we use "1"8O as a conservative to know the water sources for the lakes and our hypothesis is that: 1) In the high water stage lake water is derived predominantly from its feeding river. Therefore their #delta#"1"8O should be similar. 2) In the low water stage lake water is a mixture of watershed and last flood ...
One mitigation goal of the Hungry Horse Dam fisheries mitigation program, funded by the Bonneville Power Administration, is to replace lost production of 100,000 adult kokanee in Flathead Lake. The mitigation program calls for a five-year test to determine if kokanee can be reestablished in Flathead Lake. The test consists. of annual stocking of one million hatchery-raised yearling kokanee. There are three benchmarks for judging the success of the kokanee reintroduction effort: (1) Post-stocking survival of 30 percent of planted kokanee one year after stocking; (2) Yearling to adult survival of 10 percent (100,000 adult salmon); (3) Annual kokanee harvest of 50,000 or more fish per year by 1998, with an average length of 11 inches or longer for harvested fish, and fishing pressure of 100,000 angler hours or more. Kokanee were the primary sport fish species in the Flathead Lake fishery in the early 1900s, and up until the ...
The reactor fuel cycle based on uranium is described. The various stages in the cycle include mining of uranium ores followed by crushing and grinding, leaching and purification of leach liquor by ion exchange resin process or solvent extraction process, refining of uranium concentrate (yellow cake) by digesting with HNO_3 and then solvent extracting uranyl nitrate with TBP, conversion of uranyl nitrate to uranium hexafluoride, production of uranium metal, uranium enrichment, fabrication of reactor fuel elements and reprocessing of the spent fuel. Chemical reactions wherever they are involved are explained. (M.G.B.).
There is a continuing need to understand dose-response relationships for ionizing radiation in order to protect the health of the public and nuclear workers from undue exposures. However, relatively few human populations have been exposed to doses of radiation high enough to cause observable, long-term health effects from which to derive dose-response relationships. This is particularly true for internally deposited radionuclides, although much effort has been devoted to epidemiological studies of the few types of exposures available, including lung cancers in uranium miners form the inhalation of the radioactive decay products of Ra, liver cancers in patients injected with Thorotrast X-ray contrast medium containing Th, bone cancers in radium dial painters who ingested Ra, and bone cancers in patients who received therapeutic doses of Ra. These four types of exposures to internally deposited radionuclides provide a basis ...
The annual production of phosphate rock, on the order of about 30-40 million tons yearly, represents several million pounds of uranium. The present invention provides a process of purifying uranium tetrafluoride hydrate to produce a uranium (VI) peroxide product meeting 'yellow cake' standards using a double precipitation procedure. A fluoride complexing agent is used in the precipitation.
Simulated atmospheric corrosion studies were performed to determine the corrosion protection provided by galvanized zinc coatings on depleted uranium, U-0.75 Ti alloy, and U-6 Nb alloys. The accelerated ASTM tests consisted of exposing the galvanized samples to aqueous and aqueous chloride environments. The test results showed that anodic protection was provided by the electronegative zinc coatings on uranium and uranium alloys. Treating zinc with chromate conversion coatings also provided more protection.
The second and third member of the Qingshankou Formation recovered by CCSD-SK-Is borehole (China Cretaceous Continental Scientific Drilling-SongkeI-the south borehole) is 415.61 m long and 100% of cores recovery. The age of the member corresponds approximately to the Coniacian. The sequence and process of lithology-lithofacies and cyclic stratigraphy were revealed by a detailed core description. 12 rock types and 2 kinds of sedimentary subfacies including semi-deep lake and shallow lake were recognized from the drilling core of the second and third member of the Qingshankou Formation. 10 sedimentary microfacies are present, including dolomite, marl, limestone, oil shale, semi-deep lake turbidite, volcanic ash, seismite, semi-deep lake mudstone, shallow lake mudstone, and shallow lake turbi...
This report presents the operating results for Run 255 at the Advanced Coal Liquefaction Research and Development Facility in Wilsonville, Alabama. This run operated in the Close Coupled Integrated Two-Stage Liquefaction mode (CC-ITSL) using Martin Lake Texas lignite. The purpose of this run was to demonstrate unit and system operability with Martin Lake lignite. Run 255 began on 20 March 1988 and continued through 9 June 1988. During this period, 204.4 MF tons of Martin Lake Texas lignite were fed in 1865.5 hours of operation. 70 figs., 21 tabs.
A new three-dimensional (3D) acoustic modelling method was developed using a first-order hyperbolic wave system which was solved with explicit finite dfferences. The numerical solution of the 3D wave system provides a useful method for simulating evolution of a pressure field corresponding to compressional type waves. Existing two-dimensional (2D) elastic modelling algorithms were modified and fine-tuned for computationally efficient and realistic wave propagation simulations in complex structures. An original formulation of the 3D reverse time migration method was developed which is very accurate, does not suffer from unwanted evenescent energy, can image dips beyond 90{degree}, and does not generate multiple energy. Two case studies were performed that involved steam stimulation projects in the Cold Lakedeposit. Simulations were performed during different phases of the steam stimulation process to examine the relation between reservoir ...
Dams and reservoirs are among one of the most sensitive of all development Project, in terms of pervasiveness of their influence in altering the environmental conditions and resources. In the present study, major dams and reservoir projects are reviewed, from the environmental point of view. Dams and Reservoir projects bring about major changes in the immediate environment, thus affecting public health, settlements, farmlands, roads and historical sites. Impacts on human population and wildlife may be profound. Tropical diseases, involving fresh-water hosts or vectors in their transmission, are often common around new reservoirs. Large lakes create limnological changes, excessive evaporation, seepage, disturbance in water-table and increased tendencies of landslides and earthquakes. Micro climatic changes are possible, such as fog formation, increased cloudiness and modified rainfall-patterns. Retention of sediment results in silting up of reservoirs. Water ...
Buried soils occur on kettle floors of four Pinedale moraine catenas of the western Wind River Mountains of Wyoming. Radiocarbon ages from bulk samples of Ab horizons indicate the soils were buried during the mid-Holocene. Soils on kettle floors have silty A and Bw horizons that overlie buried A and B horizons that also formed in silt-rich sediments. Crests and backslope soils also have A and Bw horizons of sandy loam formed over 2BCb and 2Cb horizons of stony coarse loamy sand. Recent data show the silty textures of the A and B horizons are due to eolian silt and clay from the Green River Basin just west of the mountains. The buried soils appear to represent alternate periods of erosion and deposition on the moraines during the Holocene. The original soils developed on higher slopes of the moraines were eroded during the mid-Holocene and the 2BC and 2C horizons exposed at the surface. Eroded soil sediments were transported downslope onto the kettle floors. ...
Technical developments in the construction of high power accelerators have created new research activities on accelerator-driven transmutation technologies (ADTT) with main applications for energy production and nuclear waste transmutation. The on-going research was reported and discussed at the conference. The studies of energy production based on ADTT indicate possible important advantages compared to the present nuclear power reactors. Natural Uranium or Thorium is burned in a subcritical reactor with or without simultaneous incineration and transmutation of nuclear waste. High level radioactive wastes and weapons Plutonium constitute an environmental and proliferation problem. Studies were reported on the possibilities to use ADTT to considerably shorten the life-time and reduce the amount of long-lived radioactive waste in order to decrease the volumes needed for long-term geologic deposition. A panel discussed the ADTT impact on nuclear ...
The geology and resources of the lower Yellow Creek area, an area at the northwestern margin of the Piceance Creek basin comprising of four 7.5-minute quadrangles, are described. Subsurface face rocks penetrated by drill holes range in age from Pennsylvania to Cretaceous. Measured sections show the Mancos Shale and the Castlegate Sandstone, Iles Formation, and Williams Fork Formation of the Mesaverde Group of Late Cretaceous age and the Fort Union, Wasatch, Green River, and Uinta formations of Tertiary age. Surficial deposits of Quaternary age include terrace gravels, alluvium, and landslides. Fold axes and faults in the area trend northwesterly. The southern part of the area contains major oil-shale resources. Coal-bearing zones in the Williams Fork and Iles formations contain considerable coal. The coal-resources potential is limited, however, by nonpersistence of the thicker coal beds. Small amounts of gas have been produced from shallow, lenticular Tertiary ...
Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term...Full Text Available
Slide 10 Slide 11 23 ground-floor apartments Ancillary Information Gathered Median total PAH [mg/g] Slide 15 What are the principal sources of PAHs to urban lakes?...
Lake Unit AL-05P, for public review and comment. These four CBRS units are located in Baldwin and Mobile Counties, Alabama. We invite the public to review and comment on the draft...
This book, an updated version of the 1985 edition, contains thirteen chapters, beginning with a preface which provides the objective of the book. The primary objective is to offer a comprehensive survey of the biological, hydrological, mathematical, and biochemical aspects of stream, lake, estuary, and ocean pollution analysis. The book also contains ten appendices of useful tables and nomographs of pertinent data. This book provides a very good summary and review of stream, lake, estuary, and ocean pollution. This book is recommended for environmental engineering students, environmental consulting engineers, and regulatory personnel. It provides an excellent summary of the field of stream and lake analysis and modeling. Every chapter includes a significant number of questions and pertinent references.
Jul 21, 1998 ... Additional roof surface temperatures were taken with a handheld "heat spy," an infrared thermometer to help calibrate the ATLAS thermal ...
Comparative Molecular Genetic Monitoring of Myxoviruses Circulating in Populations of Seals Phoca Caspia and Phoca Sibirica in Northern Caspian Region and Lake Baikal
... of China Lake Naval Weapons Center, California. ... Figure 4: The Space-Based Laser cleaning ... of Aeronautics and Astronautics (AIAA) Space 2001 ...
The fields in this dataset are: Date Lake Depth Dissolved Organic Carbon Dissolved carbohydrates and amino acids Inorganic Nutrient Concentrations Primary ...
The authors examined the effects of large escapements of sockeye salmon in to the Kenai River and into Red and Akalura Lakes on Kodiak Island. Estimated smolt numbers outmigrating from the Kenai River decreased from 30 million in 1989 to under 500,000 in 1992. Decreased overwintering survival of age-0 juvenile sockeye salmon rearing in Skilak and Kenai lakes is the major contributor to this decline. Preliminary examination of limnological data from Skilak and Kenai Lakes provided no obvious explanation for this major decline in winter survival of juvenile sockeye. Due to differences in diel vertical migration of zooplankton among glacial lakes on the Kenai Peninsula with varying planktivores levels, the authors hypothesize that behavioral changes of zooplankton induced by predation may be a major contributor to the juvenile sockeye decline.
Report) A Screening Assessment of the Potential Impacts of Climate Change on Combined Sewer Overflow (CSO) Mitigation in the Great Lakes and New England Regions (Final Report)...
measure meteorological variables and bulk water temper- ature. The locations of the buoys are given in Table 1. TB2 and TB3 were moved slightly farther south ...
Coal mining activities cause an increased acidity and an associated decrease of the pH-value in mine waters. This process is also known as acid mine drainage (AMD). Due to AMD, lakes that were formed in the post mining landscapes in the lignite mining area of Central Germany are characterized by specific limnological development changes. Remote sensing is a time and cost saving technique that enables the observation of the hydrological and limnological development of the lakes ranging from a small to a mid size scale. The current research was based on Landsat TM5/ETM+7 satellite data collected between 1999 and 2004. In combination of satellite data, surface waters of the post mining lakes in Central Germany were sampled and analyzed for their physicochemical properties. The objective of th...
The paper describes the production of highly enriched isotopes of uranium, plutonium, americium and curium by electromagnetic separation for scientific and applied researches in physics, chemistry, geology, medicine, biology and other fields. Using the equipment described, the isotopes are produced in quantities sufficient to set up nuclear physical experiments, to produce nuclear reference materials and standard sources for calibration of radiometrical and mass spectrometrical equipment, in radionuclide metrology, etc. For the following isotopes the indicated degrees of isotopic enrichment were achieved: "2"3"3U-99.97%; "2"3"5U-99.97%; "2"3"6U-98.0%; "2"3"8U-99.997%; "2"3"8Pu-99.6%; "2"3"9Pu-99.9977%; "2"4"0Pu-99.9-100%; "2"4"1Pu-96.998%; "2"4"2Pu-97.8-99.96%; "2"4"4Pu-96.7%; "2"4"1Am-99.6%; "2"4"2"mAm-73.6%; "2"4"3Am-99.2-99.94%; "2"4"3Cm-99.99%; "2"4"5Cm-99.998%; "2"4"6Cm-99.8%; "2"4"7Cm-90%, "2"4"8Cm-97%. Methods for preparing layers of highly enriched isotopes ...
Gabal Ralal is one of the major asymmetrical doubly- plunging anticlinal fold belts (50 Km length) related to the Syrian Arc System in northern Sinai, Egypt. The exposed rock units at Gabal Ralal range from Cretaceous to Quaternary and are divided into eight formations which are from base to top: Malha, Ralal, Wata, Themed, Sudr, Beida, Egma and Quaternary wadi deposits. The image processing is applied using Landsat-7 satellite data to discriminate structure and lithology for defining the horizons of the radioactive anomalies of each rock unit. The extracted structural lineaments, using Ge Analyst-PCl package, from digital ETM data showed that the main structural trends are NE-SW and NW-SE normal faults which originated as extensional fractures with lateral dip-slip displacement. The axial trace of Gabal Ralal fold is curved and plunging to Wand SW directions while the northeastern part (Gabal Dalfa) is plunging to NE direction. The use of remote sensing data and ...
As a part of the compatibility analysis of DUPIC fuel in CANDU reactors, the radiation physics calculations have been performed for the CANDU primary shielding system, thermal shield, radiation damage, transportation cask and storage. At first, the primary shield system was assessed for the DUPIC fuel core, which has shown that the dose rates and heat deposition rates through the primary shield of the DUPIC fuel core are not much different from those of natural uranium core because the power levels on the core periphery are similar for both cores. Secondly, the radiation effects on the critical components and the themal shields were assessed when the DUPIC fuel is loaded in CANDU reactors. Compared with the displacement per atom (DPA) of the critical component for natural uranium core, that for the DUPIC fuel core was increased by -30% for the innermost groove and the weld points and by -10% for the corner of the calandria ...
A critical review of the literature revealed no experiments on uranyl ion transfer from an aqueous to a tributyl phosphate phase which positively measured the kinetics of the chemical reaction at the interphase. Drawing isorhythmic lines on a three component diagram gives a complex correlation for the compaction of three sizes of glass beads. Neither the use of thoria sols nor high feed solution concentrations of thorium nitrate gave any significant increase in mean particle diameters over those obtained from nitrate solutions of lower concentrations in flame denitration. A hydraulic film resistance has been detected in the anion exchange of uranyl sulfate into Dowex 2lK, and chloride elution was found to give a higher apparent uranium diffusion coefficient than nitrate elution. The rate of dissolution of mixed thorium-uranium oxides was determined as a function of the per cent of mixed oxides dissolved. Mixing in ...
The main activities developed at 'Instituto de Energia Atomica' Sao Paulo, Brazil, on the recovery of uranium from ores, the purification of uranium and thorium raw concentrates and their transformation in nuclear grade compounds, are reviewed. The design and assemble of pilot facilities for ammonium diuranate (ADV) uranium tetrafluoride, uranium trioxide, uranium oxide microspheres, uranyl nitrate denitration, uranim hexafluoride and thorium compounds are discussed. The establishment of analytical procedures are emphasized.
The results of calculational comparative study into radiotoxicity and residual power release time dependences for spent uranium-plutonium and thorium-uranium nuclear fuels from the WWER-1000 reactors during ling- time (up to 300 thousand years) storage are discussed. It is shown that the total radiotoxicities for actinides from uranium, uranium-plutonium and thorium-uranium spent fuels at storage period begin amount to 5.2 x 10"1"4, 1.3 x 10"1"5 and 1.5 x 10"1"4 kg of water per 1 t of discharged fuel, respectively. Radiotoxicity of actinides in uranium-plutonium fuel is revealed to be by the factor of 2.5 greater than that for ordinary uranium fuel because of greater accumulation of "2"3"9Pu, "2"4"0Pu, "2"4"1Pu and "2"4"4Cm. Radiotoxicity of actinides for thorium-uranium fuel calculated taking into account "2"3"4U is ...
We used microarrays and a previously established linkage map to localize the genetic determinants of brain gene expression for a backcross family of lake whitefish species pairs (Coregonus sp.). Our...Full Text Available
...ER14AU08.000 (6) Unit 2: North Baldwin Meadow, San Bernardino County, California...and ARUR 12. Gold Mountain and North Baldwin Lake, San Bernardino County, California...ER26DE07.007(13) Unit ARUR 15. South Baldwin Ridge/Erwin Lake, San Bernardino...
The previous judgment of eutrophic state, once proposed for the Trasimeno Lake (Umbria region, Italy), has been revised. According to Vollenweider-OECD classification criterion, the lake waters are at present to be classified as mesotrophic waters, with phosphorus limitation. However this level of moderate productivity results to be conditioned by the hydrochemical characteristics of the lake waters, that control phosphorus concentrations independently from the loading coming from the basin, and prevent dangerous and massive algal blooms. Different processes of chemical nature, regulating the phosphorus amount in the lake waters, are then reviewed: adsorption of P/P0(4) onto suspended materials, particularly clay mineral particles, and direct precipitation as hydroxylapatite or co-precipitation with carbonates, are found to be the principal mechanisms that determine chemical removal of phosphorus from ...
Tetracycline in solution of benzyl alcohol was used as an extracting agent to separate uranium from interfering elements in the determination of uranium and of isotopic ratio sup(235)U/sup(238)U by neutron activation analysis. Separation gives a recovery of 97% for uranium and the interferences from matrices of pitchblende and monazite are eliminated.
Molybdenum is separated from molybdenum-containing activated charcoal or char also containing small amounts of uranium obtained as a by-product in uranium leaching processes by stripping with an alkaline solution to provide a molybdenum containing solution containing substantially less than 500 ppm u/sup 3/o/sup 8/.
Daily exposures of adult beagle dogs to inhaled radon daughters and to uranium ore dust for 4-1/2 to 6 yr have produced respiratory tract carcinomas, at similar cumulative working level months (WLM) of exposures to those which induced carcinomas in uranium miners. Biological data from the beagle-dog experiments can therefore be used for prediction of carcinogenic risk under changing exposure conditions in future uranium miners.
For the treatment of dam waste water containing micro quantities of uranium, the so-called chemical precipitation method is conventionally used, that is, acidic sodium phosphate is added to it and so the uranium (UO_2"2"+) is removed in coprecipitation with the then occurring calcium phosphate (solid). The method, however, has several problems, such as the large space required and large quantities of sludge. For the pupose of eliminating such difficulties and removal and recovery of the uranium, development of the new uranium adsorption method was started. Of the many uranium adsorbents available, excellent ones were selected and then the continuous treatment test was made with small apparatus. Subsequently, the dam waste water uranium recovery facility was completed in 1983. (Mori, K.).
The potential use of uranium in the field of catalysis is presented in the first part of this paper. Numerous applications of uranium binary oxides, as well as mixed oxides, are reviewed with a special emphasis on the role of U-Sb-O catalysts in selective oxidation (and ammoxidation) processes. Attempts are made to correlate the electronic structure of uranium, and especially the role that 5f electrons play in bonding, with its promising catalytic properties. In the second part, new data are given for uranium-bismuth mixed oxides in the catalytic oxidation of CO by O_2. Kinetic tests performed in a flow microreactor allow a mechanism to be proposed that involves the direct participation of lattice oxygen of the catalyst in the chemical process (redox mechanism). The high activity can be related to the ability of uranium to change reversibly its oxidation state. (author).
The potential use of uranium in the field of catalysis is presented in the first part of this paper. Numerous applications of uranium binary oxides, as well as mixed oxides, are reviewed with a special emphasis on the role of U-Sb-O catalysts in selective oxidation (and ammoxidation) processes. Attempts are made to correlate the electronic structure of uranium, and especially the role that 5f electrons play in bonding, with its promising catalytic properties. In the second part, new data are given for uranium-bismuth mixed oxides in the catalytic oxidation of CO by O/sub 2/. Kinetic tests performed in a flow microreactor allow a mechanism to be proposed that involves the direct participation of lattice oxygen of the catalyst in the chemical process (redox mechanism). The high activity can be related to the ability of uranium to change reversibly its oxidation state.
It is essential that alumina used for manufacturing electronic devices should contain an extremely low level of alpha-radiation. The principal source of alpha-radiation in alumina is uranium, a minor source being thorium. Uranium in bauxite dissolves into the liquor in the digestion process and is fixed to the red mud as the desilication reaction progresses. A part of uranium remaining in the liquor precipitates together with aluminum hydroxide in the precipitation process. The uranium content of aluminum hydroxide becomes lower as the precipitation velocity per unit surface area of the seed becomes slower. Organic matters in the Bayer liquor has an extremely significant impact on the uranium content of aluminum hydroxide. Aluminum hydroxide free of uranium is obtainable from the liquor that does not contain organic matters.
Approximately 1.2 million kg of uranium oxide (yellow cake) has been produced from the area surrounding Gunnison, Colorado. Over 99 percent of this has come form the Cochetopa and Marshall Pass districts. Uranium in both districts and many of the other occurrences is associated closely with fault and shear zones which cut brittle host formations (sandstones and dolomites) of Paleozonic and Mesozoic age. Minor uranium occurrences are in pegmatites and shear zones in Precambrian rocks, Cambrian vein material, and sandstones of Tertiary age. In the paper presented, the uranium occurences are described by districts. In addition, possibilities for additional discoveries are discussed. (JMT)
Investigations were conducted at Los Alamos National Laboratory to quantify the extent of migration of depleted uranium away from firing sites. Extensive sampling of air particles, soil, sediment, and water was conducted to establish the magnitude of uranium contamination throughout one watershed. The uranium source term was estimated, and mass balance calculations were performed to compare the percentage of migrated uranium with original expenditures. Mass balance calculations can be powerful in identification of the extent of waste migration and used as an aid in planning future waste investigations.
Saskatchewan boasts the greatest concentration of high-grade uranium of any place in the world. Properly managed, its current reserves of 238U can easily fuel the entire province for some 10,000 years (in comparison, the world's oil supplies may be gone in 100). It is likely that Saskatchewan, with all that uranium, can build an industry and renew Canada's nuclear dream. The authors believe in the value of nuclear energy, in general, and the value of uranium mining in Saskatchewan and other parts of the world, in particular. We also believe in the value of research, development, innovation and training in the nuclear industry and the uranium industry
Processes of production and purification (necessary for fabricating fuel elements) of powdery uranium dioxide with particle size up to 1000 #mu#m and more have been studied. Developed is continuous process of UO_2 production with above particle size by converting uranium hexafloride into UO_2 solid particles in fluidized bed while their interaction with water vapor and hydrogen on the uranium dioxide nucleus material. The method allows to conduct continuous selection from the apparatus of UO_2 powder fraction with particle size near 1000 #mu#m without nucleus material additional feed.
The near-term availability of domestic and selected foreign uranium resources for use by United States electric utilities is considered in light of projected geopolitical and socioeconomic considerations. No attempt is made to analyze the impact on domestic uranium supply of inflation or cost-price considerations, the introduction of the breeder reactor, limitations in enrichment capacity, or the presently expanding uranium inventory. All data are current as of mid-1980. The period with which this research is concerned is 1980-1995. It is concluded that the United States must promote responsible, environmentally acceptable uranium resource exploration and development, if this nation is to remain self sufficient in this necessary energy commodity.
The manufacturing of TRIGA fuel rods with low enriched uranium follows in principle the same route as high-enriched uranium. The high purity of the primary metals (uranium, zirconium and erbium) is important for determining the equilibrium metal-hydrogen phases. The impurities from the metal, on the surface and from hydrogen may have an important influence on the hydriding process. This paper presents the aspects of the fuel contamination with oxygen during the manufacturing process of the low enriched uranium fuel. The continuous control of the oxygen concentration in the working zone ensures avoidance of the accidental contamination. Key words: manufacturing, fuel, oxygen, contamination. (authors)
Metastable yttrium-oxide films are synthesized using reactive sputter deposition. The yttrium concentration of the as-deposited film is found to vary as a function of the sputter deposition rate. In addition to the synthesis of the cubic equilibrium phase...
Water-resources data for the 1993 water year for Minnesota consists of records of stage, discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. This volume contains discharge records for 58 gaging stations; stage and contents for 9 lakes and reservoirs; water quality 15 stream stations, 1 lakes station, 1 precipitation station, and water levels for 15 observation wells. Also included are 61 high-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program and are pulished as miscellaneous measurements.
Water-resources data for the 1991 water year for Minnesota consist of records of stage, discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. The volume contains discharge records for 60 gaging stations; stage and contents for 9 lakes and reservoirs; water quality for 18 stream stations, 1 lake station, 22 partial-record sites, 1 precipitation station, 108 wells; and water levels for 119 observation wells. Also included are 59 high-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program and are published as miscellaneous measurements or low-flow investigations.
Water?rock interaction is one of the prime factors affecting the fluoride contents of surface and groundwater. If fluoride concentration of drinking water has been neglected, excess fluoride can cause serious dental and medical problems on human health, which is well known at Golcuk-Isparta region. In the research area, Egirdir lake, Golcuk lake and surrounding springs have been utilized as drinking water sources. Golcuk lake water and surrounding groundwaters have high fluoride content (1.4?4.6?mg/l), which is above the WHO standards. Fluoride is predominantly supplied by dissolution of fluoride within the fluormicas of volcanics during the circulation of water. Fluoride concentrations of waters have shown variations for dry and rainy seasons depending on the degree of interaction between...
Graphical Abstract A Southward view of the Dead Sea western coast. The steep western escarpment of the Dead Sea basin, composed mainly of Upper Cretaceous limestone and dolomite, can be seen on the right. Beach terraces left by the shrinking lake run parallel to the shore. The larger part of the area between the present water line and the mountains was still under Dead Sea water just 50?60?years ago. The current fall of the lake?s stand is around 1?m?year?1. Three on-shore sinkholes can be seen in the front of the photo, as well as two submerged ones near its lower left corner. These were caused by dissolution of a Holocene salt layer located tens of meters below the surface, resulting in the collapse of the overlying sediments. The retreat of the Dead Sea in recent years was followed by e...
A sensitive and rapid method to evaluate toxic and genotoxic properties of drinking water supplied from Lake Trasimeno (Umbria, Central Italy) was worked out analysing bile in Cyprinus carpio exposed for 20d to lake water treated with 3 different disinfectants, sodium hypochlorite (NaClO), chlorine dioxide (ClO2) and peracetic acid (PAA). Fish were sacrificed at 0, 10 and 20d in order to investigate the time course of these endpoints. An aliquot of bile samples was fractionated by adsorption on C18 silica cartridges and the genotoxic potential of whole bile and of bile fractions was evaluated by the single-cell microgel-electrophoresis (comet) assay on human colonic adenocarcinoma cells (Caco-2). Bile (both whole and fractionated) from specimens exposed to the three disinfectants always sh...
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m{sup 3} in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m{sup 2} in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m3 in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m2 in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit contamination of land and the public.
Sediment trap fluxes of solids, organic carbon, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) were measured in Lake Superior in 1984 and 1985. Mass fluxes from surface waters ranged from 0.14 to 1.1 g/m{sup 2}{center dot}day and increased near the lake floor due to resuspension of surficial sediment and horizontal transport in the benthic nepheloid layer. Organic matter fluxes from surface water ranged from 60 to 90 mg of C/m{sup 2}{center dot}day, with {approximately}5% of organic carbon settling from surface waters accumulating in bottom sediments. Concentrations of PCBs and PAHs are enriched 10-100 times on settling particles relative to those on suspended particles. Resultant settling fluxes are 10-100 times greater for several PCB and PAH compounds than net accumulation rates in bottom sediments, indicating the effective and rapid recycling in the benthic region. Biological packaging of organic pollutants ...
A pilot project was started in 1977 over the Lake Superior basin to measure water storage on the land area using aerial gamma-ray spectrometry to provide hydrologic information for forecasting inflow to the lake. Two airborne surveys were made, respectively in November 1977 and March 1978 which provided estimates of the increase in snow water equivalent between these surveys. The basin is located on the Canadian Shield and consequently, the gamma radiation count rate is quite variable. The airborne results are compared with ground measurements on selected flight lines and show generally good agreement. Two equipment calibrations in the Ottawa area provided inconsistent parameter values which are consequently also reflected in the results over the Lake Superior basin. The project has demonstrated to-date that the technique can be developed into an operational system for measuring snow cover water equivalent of this vast and ...
The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire ...
... 154. By way of comparison, the aquatic weed Hygrophila polysperma (Roxb.) T. Anderson, a potential target for biological ... L. Sutton. 2000. Is the aquatic weed hygrophila, Hygrophila polysperma (Polemon...
Green Lake Landslide is an ancient giant rock slide in gneiss and granodiorite located in the deeply glaciated Fiordland region of New Zealand. The landslide covers an area of 45km2 and has a volume of about 27km3. It is believed to be New Zealands largest landslide, and possibly the largest landslide of its type on Earth. It is one of 39 known very large (106-107 m3) and giant (?108m3) postglacial landslides in Fiordland discussed in the paper. Green Lake Landslide resulted in the collapse of a 9km segment of the southern Hunter Mountains. Slide debris moved up to 2.5km laterally and 700m vertically, and formed a landslide dam about 800m high, impounding a lake about 11km long that was eventually infilled with sediments. Geomorphic evidence supported by radiocarbon dating indicates tha...
BackgroundCichlid fishes in Lake Tanganyika exhibit remarkable diversity in their feeding habits. Among them, seven species in the genus Perissodus are known for...Full Text Available
The focus of the present Great Lakes water quality agreement between Canada and the United States is on transboundary pollution and particularly the injury to health and property from exposures to persistent toxic substances. Several scientists and policy advisors have suggested, on the basis of the Ecosystem Approach and systems theory, that the agenda should move on to other demanding topics, such as the introduction of exotic species, biodiversity, habitat restoration, fisheries management, sustainable development, and governance of the Great Lakes basin. None of these issues, however, poses the same scale of threat to national sovereignty and bilateral interests as does transboundary pollution. Thus, none warrants the degree of attention that has been and should be paid, despite declining budgets, to assessing and controlling releases of persistent toxic substances that continue to injure fish, wildlife, and human health. Instead, it is ...
Volume 2 of the water resources data for the 1992 water year for Oklahoma consists of record of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes or reservoirs; and water levels of ground-water well. The report contains discharge records for 136 gaging stations; stage and contents for 31 lakes or reservoirs; water quality for 50 gaging stations. Also included are 61 partial-record or miscellaneous streamflow stations and 28 ground-water sites.
We review the status of the Lake Baikal Neutrino Experiment. Preparation towards a km"3-scale Gigaton Volume Detector (GVD) in Lake Baikal is currently a central activity. As an important milestone, a km"3-prototype string comprising of 12 optical modules and based on a completely new technology, has been installed and was put in operation together with NT200+ in April, 2009. We also present recent results from the long-term operation of NT200, including an improved limit on the diffuse astrophysical neutrino flux.
The effects of variable hardness, pH, alkalinity, humics, and suspended clay on the chemical speciation of copper and its toxicity to fathead minnow larvae in Lake Superior water were investigated. Two proposed methods (toxicity factors and chemical speciation) for predicting LC50 values in specific natural waters from laboratory toxicity data and the average site specific values of general water quality parameters were evaluated. The accuracy of the cupric ion-selective electrode in determining CU/sup +2/ activities in ambient and chemically altered Lake Superior water was also determined.
Oxydes d'Uranium et de Plutonium. J. Nucl. Mat., vol. 33, no. 1, Oct. 1969, pp. 40-51. 21. Hall, A. R.: Elastic Moduli and Internal Friction of Some Uranium ...
ObjectivesTo assess the distribution and risk factors of depleted uranium uptake in military personnel who had taken part in the invasion of Iraq in 2003.MethodsSector...Full Text Available
Determination of the specific surface of uranium oxides: UO_2 and U_3O_8 using a simplified equation derived from the Brunauer, Emmett and Teller theory. The method is suitable for samples having a surface between 6 to 50 m"2.
Adsorption of uranium onto various solids is important from purification, environmental, and radioactive waste disposal points of view. Adsorption of uranium on activated charcoal has been studied as a function of shaking time, amount of adsorbent, pH, concentration of adsorbate, and temperature. Uranium adsorption obeys the Langmuir isotherm. {Delta}H{degrees} and {Delta}S{degrees} were calculated from the slope and intercept of plots ln K{sub D} vs 1/T. The influence of different anions and cations on uranium adsorption has been examined. The adsorption of other metal ions on activated charcoal has been studied under specified conditions to check its selectivity; consequently, uranium was removed from Cs, Ba, Zn, and Co. More than 98% adsorbed uranium on activated charcoal can be recovered with 65 ml of 3 M HNO{sub 3} solution. A wavelength dispersive x-ray ...
This report describes a field-test program to determine the effectiveness of a polymeric wall sealant to reduce the escape of naturally occurring radioactive gas radon from the walls of an underground uranium mine into the ventilation air.
Uranium(VI)-salicylic acid system has been studied polarographically in perchloric acid medium. Varying concentrations of HClO/sub 4/ and salicylic acid have been used. The nature of the polarographic waves is irreversible.
The storage and distribution of copper, cadmium, and uranium and their effects on ionic contents in roots and shoots of Azolla filiculoides has been studied by x-ray microanalysis....Full Text Available
In this paper, we present experimentally determined reflection factors of mirrors based on the depleted uranium and dependence of reflection factor on time of presence of samples on air.
The desorption of uranium from the granular titanium-activated carbon composite adsorbent (concentration of uranium: 25.5 mg/l-Ad), which adsorbed uranium from natural sea water, was examined by the column process with acidic eluent at room temperature. The column operation was able to be carried out without destruction of the granular adsorbent by the generation of the carbon dioxide, and free from disturbance of the eluent flow by precipitate of calcium sulfate dihydrate with sulfuric acid eluent. The amount of acid consumption by the adsorbent was 0.87 eq/l-Ad. The alkaline earth metals were eluted in the range of elution volume below 2l/l-Ad, whereas uranium, iron, and titanium were eluted above 2l/l-Ad. Therefore, uranium was separable from the alkaline earth metals which were adsorbed in the most quantity in the adsorbent. In the range of elution volume 2 to 12l/l-Ad, the ...
In this paper, the following topics are studied: uranium 238 effective integral; thermal range uranium 238 capture cross section; Americium 242 m capture cross section. The mentioned examples show that differential and integral experiments are both useful...
A method to reduce the fuel composition heterogeneity effect on the core performance parameters has been studied for the DUPIC fuel which is made of spent pressurized water reactor (PWR) fuels by a dry refabrication process. This study focuses on the reactivity control method which uses either slightly enriched, depleted, or natural uranium to minimize the cost rise effect on the manufacturing of DUPIC fuel, when adjusting the excess reactivity control by slightly enriched and depleted uranium, reactivity control by natural uranium for high reactivity spent PWR fuels, and reactivity control by natural uranium for linear reactivity spent PWR fuels. The results of this study have shown that the reactivity control by slightly enriched and depleted uranium, all the spent PWR fuels can be utilized as the DUPIC fuel and the fraction of fresh uranium feed is 3.4% on an ...
The accuracy of the carbon 14 dating method is dependent on the fluctuations of carbon 14 in the atmosphere over long periods of time. Fossil corals that are dated by both carbon 14 and uranium-thorium methods allows the setting of calibration curves for the carbon 14 method for the last 50.000 years. The uranium-thorium method is based on the measurement of the ratio of 2 isotopes: thorium 230 and uranium 234 that are both present in the decay chain of uranium 238. (A.C.)
Radiological hazard in uranium mining and milling operations are primarily due to exposure to external beta and gamma radiation as well as to airborne radionuclides which consist of radon and its short-lived daughter products. In May 1981 a radiological survey programme was performed in order to make a general assessment of the radiation hazards associated with the uranium mines and the Uranium Pilot Plant operated by the M.T.A. Institute in the Koprubasi district of the Manisa province. In this paper a preliminary radiological risk evaluation attempt is presented based on the radiation and radioactivity measurements performed in this district in May 1981.
The purpose of the present research is to find a suitable technique to measure trace amounts of uranium and thorium and to determine the surface #alpha#-flux in silicon compound (SiO) used for fabrication of integrated circuit packaging materials. Among several commonly-used detecting techniques, it was found that neutron activation analysis (NAA) was most promising. The results from NAA show a large difference in uranium and thorium concentrations when cadmium and boron carbide shields are used, whereas #alpha#-flux measurements show a low #alpha#-activity, which corresponds to the trace amounts of uranium and thorium expected to be present in these materials. (author) 13 refs.; 6 figs.
Selected samples of waste microbial biomass originating from various industrial fermentation processes and biological treatment plants have been screened for biosorbent properties in conjunction with uranium and thorium in aqueous solutions. Biosorption isotherms have been used for the evaluation of biosorptive uptake capacity of the biomass which was also compared to an activated carbon and the ion exchange resin currently used in uranium production processes. Determined uranium and thorium biosorption isotherms were independent of the initial U or Th solution concentration. Solution pH affected the exhibited uptake. 24 refs.
Heyuan mineralization belt is a structure-magmatic activities belt which is charcterized by strong plastic deformation and shearing. The squeeze (overthrust) structure is formed early. Later stretch produced slide shovel-shaped normal fault which control the red basin and uranium mineralization. Comprehensive study shows that this area is of favorable uranium metallogenic condition due to the rich uranium source and higher degree of geology work, it is a target for the new round resources exploration. (authors)
The proceedings of the third RAAN conference, titled 'RAAN as Support of Nuclear Power', held in Drobeta Turnu-Severin, Romania on 6-7 Nov 2003, are structured on three sections covering the following issues: - Section 1. Energy and Environment (19 papers); - Section 2. Isotopic products (3 papers); - Section 3. Prospects of Nuclear Power development in Romania (17 papers). Nuclear power in Romania was initiated on the basis of CANDU reactor type technology, an option found able to fulfill the requirements for a sustainable economic development, to support the electric energy demand of the country and to ensure the population and environment protection. The construction of the Cernavoda NPP was heavily based on the Romanian industry participation and basic and applied nuclear research national resources. The experience acquired from Cernavoda NPP Unit 1 will be fruitfully used in construction of the Units 2-5 to be built. Lately Romania's economy recorded a significant grow what ...
Methods of preparation, stability in solutions and in the solid phase, composition of orthophosphate crystallohydrates and condensed uranyl- and uranium (4) phosphates, are considered. Structures of these compounds are discussed; it is shown that they are steric polymers with an uranylphosphate framework. The problem of phosphate-anion polymerization in the process of thermal decomposition is discussed. It is established that condensed uranyl polyphosphates are not stable during storage, capable of degradation, its degree increasing with the phosphate chain length and uranium content.
The TTT diagrams describing the beta to alpha isothermal transformation have been made by isothermal dilatometry for pure uranium and 21 alloys based on chromium, silicon, molybdenum, iron, aluminium, zirconium. The thermal cycle preceeding the isothermal...
Daily exposures of adult beagle dogs to inhaled radon daughters plus uranium ore dust, with and without concurrent cigarette smoking, for 2 to 5-1/2 yr have produced massive pulmonary fibrosis and severe emphysema. The cumulative exposure doses are similar to those associated with a 5-fold or greater increase in death rate of uranium miners due to chronic respiratory insufficiency, including pneumoconiosis, pulmonary fibrosis, and emphysema.
Achievements in the field of sorption recovery of uranium from sea water are considered in brief. Polyacryl amidoxime chelate iorites are shown to exceed in sorption properties both titanium dioxide base natural adsorbents and styrene base synthetic resins. Merits of sorbents containing fixed layer of humic acid are pointed out, different methods of their application are considered. The cost of uranium recovery from sea water using different sorbents is estimated.
Guidelines for uranium residual radioactive material in soil were derived for the B&T Metals Company site in Columbus, Ohio. This site has been identified for remedial action under the US Department of Energy`s (DOE`s) Formerly Utilized Sites Remedial Action Program (FUSRAP). Single-nuclide and total-uranium guidelines were derived on the basis of the requirement that following remedial action, the 50-year committed effective dose equivalent to a hypothetical individual living or working in the immediate vicinity of the site should not exceed a dose constraint of 30 mrem/yr for the current use and likely future use scenarios or a dose limit of 100 n-mrem/yr for less likely future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation. RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines. Three scenarios were ...
Many factors influence radon-222 influx and radon-daughter concentrations in underground uranium mines. A brief review of some of these factors is presented. Current radon-222 and radon-daughter control principles and practices for US underground uranium mine atmospheres are discussed and a brief review of the applicability of other possible control methods such as rock sealants, radon-222 removal, and radon-daughter removal is given.
Atmospheric pressure plasma enhanced chemical vapour deposition system is built. The electrical and optical characteristics of the APPECVD system is given. The system is used to deposit conductive polymers and nano composites onto glass and metal surfaces. The morphological, optical, chemical and electrical characteristics of deposited surfaces are investigated using SEM, AFM four probe deposition purposes. The photovoltaic applications of plasma deposited polymers and nonconsumption are compared with deposited with electrochemical methods show different results. The electrical, chemical and morphological structures of the samples will be given.
SKB is currently performing site investigations at two potential sites for a final repository for spent nuclear fuel. This report presents results of water flow and solute transport modelling of the Forsmark site. The modelling reported in this document focused on the near-surface groundwater, i.e. groundwater in Quaternary deposits and shallow rock, and surface water systems, and was performed using the MIKE SHE tool. The most recent site data used in the modelling were delivered in the Forsmark 2.3 dataset, which had its 'data freeze' on March 31, 2007. The present modelling is performed in support of the final version of the Forsmark site description that is produced during the site investigation phase. In this work, the hydrological modelling system MIKE SHE has been used to describe near-surface groundwater flow and the contact between groundwater and surface water at the Forsmark site. The surface water system at Forsmark is described with ...
Biosorption of elements is a little understood phenomenon exhibited by some types of even nonliving microbial biomass. A common fungus Rhizopus arrhizus has been reportd to take up uranium from adqueous solutions to the extent of 180 mg U/sup 6 +//g. The mechanism of uranium sequestering by this type of biomass was studied by using experimental techniques such as electron microscopy, x-ray energy dispersion analysis, IR spectroscopy, and supporting evidence was obtained for a biosorption mechanism consisting of at least three processes. Uranium coordination and adsorption in the cell-wall chitin structure occur simultaneously and rapidly whereas precipitation of uranylhdroxide within the chitin microcrystalline cell-wall structure takes place at a lower rate. Interference of Fe/sup 2/ and Zn/sup 2 +/ coions with uranium biosorption is indicated.
Improved biosorption of uranium by Kluyveromyces marxianus IMB3 biomass was achieved by increasing the electric field strength of delivered pulses from 1.25kV/cm to 2.5kV/cm. Although this had little or no effect on the maximum biosorption capacity (q(max)), at low concentrations of uranium the amount bound to the biomass increased from 70 to 140mg uranium/g biomass. Significant increases in the maximum biosorption capacities (119-180 mg uranium/g biomass) were observed when the pulse field strength was increased from 2.5kV/cm to 3.25kV/cm. (Author).
A flowing bed kiln is a gas-solid reactor used in the civil nuclear fuel cycle for the successive conversion of uranium trioxide (UO{sub 3}) into uranium dioxide (UO{sub 2}) and then into uranium tetrafluoride (UF{sub 4}). A numerical model is developed which simulate the behaviour of this reactor in permanent regime. This model describes the physico-chemical phenomena involved, and combines a mechanistic approach in the vertical area of the kiln (resolution by the finite volumes method) and a systemic approach in the horizontal area, like in the model of cascade mixers. The first results have been obtained for reference operating conditions of the industrial kiln. Some possible improvements of the optimum temperature progression inside the kiln are evoked. (J.S.)
Whilst unwashed preparations of biomass from a local brewery had an apparent maximum biosorption capacity for uranium of 360 mg/g (dry weight biomass) washing reduced this maximum to 150 mg/g. Homogenization of both biomass preparations and recovery of cellular debris had no significant effect on the maximum biosorption capacities although at lower equilibrium concentrations of uranium differences in the biosorption capacities were detected. When unwashed biomass was retained by a semi-permeable membrane 40% of uranium used in the experiments precipitated outside that membrane. Therefore a significant proportion of the uranium removed from solution, and previously attributed to biosorption by the yeast biomass, resulted from precipitation brought about by interaction with low molecular weight components loosely associated with the biomass. (Author).
A process is described for the recovery of uranium values from phosphoric acid utilizing an alkyl pyrophosphoric acid (Appa) primary extractant. After extracting the uranium from the phosphoric acid, the appa extractant is deactivated by heating and the uranium values stripped into a phosphoric acid strip solution containing ferric ion as a salting agent. The uranium values may then be re-extracted directly from this stripping solution without adjustment of its concentration into a dialkyl phosphoric acid trialkyl phosphine oxide synergistic extractant from which a relatively pure yellow cake is precipitated. A new procedure for preparing the requisite appa primary extractants is also disclosed.
Simultaneous exposures of rats and hamsters to inhaled radon daughters, with and without uranium ore dust, were performed daily for five months. Pulmonary pathology developing in 6 to 13 mo after cessation of daily exposures included interstitial fibrosis, emphysema, epithelial hyperplasia, squamous metaplasia, and malignant neoplasia. Rats showed a greater variety and more severe response to these uranium mine inhalation exposures than did hamsters. Inhalation of radon daughters with uranium ore dust displayed the site of greatest damage, including squamous carcinoma, from the nasopharynx to the lungs. Sixty percent of the rats exposed to radon daughters with ore dust developed primary pulmonary carcinomas, providing an appropriate short-term experimental animal model for investigation of respiratory tract carcinogenesis in uranium miners.
The aim of this work is to simulate the reduction by hydrogen of the tri-uranium octo-oxide U{sub 3}O{sub 8} (obtained by uranium trioxide calcination) into uranium dioxide. The kinetics curves have been obtained by thermal gravimetric analysis, the hydrogen and steam pressures being defined. The geometrical modeling which has allowed to explain the trend of the kinetics curves and of the velocity curves is an anisotropic germination-growth modeling. The powder is supposed to be formed of spherical grains with the same radius. The germs of the new UO{sub 2} phase appear at the surface of the U{sub 3}O{sub 8} grains with a specific germination frequency. The growth reactivity is anisotropic and is very large in the tangential direction to the grains surface. Then, the uranium dioxide growths inside the grain and the limiting step is the grain surface. The variations of the growth reactivity and of the ...
From 1980 to 1993, the domestic production of uranium declined from almost 44 million pounds U{sub 3}O{sub 8} to about 3 million pounds. This retrenchment of the U.S. uranium industry resulted in the permanent closing of many uranium-producing facilities. Current low uranium prices, excess world supply, and low expectations for future uranium demand indicate that it is unlikely existing plants will be reopened. Because of this situation, these facilities eventually will have to be decommissioned. The Uranium Mill Tailings and Radiation Control Act of 1978 (UMTRCA) vests the U.S. Environmental Protection Agency (EPA) with overall responsibility for establishing environmental standards for decommissioning of uranium production facilities. UMTRCA also gave the U.S. Nuclear Regulatory Commission (NRC) the responsibility for licensing and ...
This Executive Summary, Volume I, of the lower Flathead System Fisheries Study Final Report, was prepared to provide a study overview for persons who are not fisheries scientists. The contents provide an introduction to the study and its objectives, a short description of the study area, a discussion of the major findings and conclusions of the study, and the description of fisheries management alternatives available to managers of the lower Flathead system. Technical reports were prepared for those portions of the study dealing with the lower Flathead River and its tributaries, Volume II, and the South Bay of Flathead Lake, Volume III. The annual hydrographic regime of the Flathead system, consisting of upper rivers, lake and lower river, has been modified by the construction and operation of two major hydroelectric facilities, Hungry Horse Dam on the south fork Flathead River and Kerr Dam at the outlet of Flathead Lake. ...
Three algal bioassay experiments were conducted from March 1992 through September 1993 in an area of Lake Mead that has experienced problems associated with severe nutrient enrichment. The first experiment determined the effects of elevated CO2 (700 ppm) (2xCO2), vs ambient CO2 on the natural algal assemblage without nutrient enrichment. The second experiment determined the effects of 2xCO2 on nutrient enriched bioassays and if nutrients were limiting. The third experiment examined elevated temperatures and 2xCO2. Nested climate models were used to predict changes in water temperatures and thermocline development in Las Vegas Bay. The lake model predicted an increase in mean water temperatures of 1.8 deg under a 2xCO2 scenario. A thermocline definition of 1 deg. C change per 2-m depth was applied to water temperatures developed by a lake model coupled to nested general circulation and regional-scale atmospheric models in ...
A simple and rapid laser fluorometric determination of trace and ultra trace level of uranium in a wide variety of low uranium content materials like soil, basic and ultra basic rocks, plant ash, coal fly ash and red mud samples is described. Interference studies of some common major, minor and trace elements likely to be present in different geological materials on uranium fluorescence are studied using different fluorescence enhancing reagents like sodium pyrophosphate, orthophosphoric acid, penta sodium tri-polyphosphate and sodium hexametaphosphate. The accurate determination of very low uranium content samples which are rich in iron, manganese and calcium, is possible only after the selective separation of uranium. Conditions suitable for the quantitative single step extraction of 25 ng to 20 #mu#g uranium with tri-n-octylphosphine oxide and single step ...
Additional measurements have been made of deposition and retention of inhaled radioactively labeled iron oxide aerosols generated by a spinning top aerosol generator.
This work describes the use of volatile halocarbons in a pulp mill effluent, including chloroform, bromodichloromethane, and tri- and tetrachloroethylene, as tracers for the distribution and movements of effluent currents in a receiving water bay (Jackfish Bay) on the northern shore of Lake Superior. The results indicate the simplicity and usefulness of the technique and the significantly improved resolution of effluent plume delineation over the customary use of conductance profiles. Concentration patterns of the effluent volatiles suggest counterclockwise circulation of bay water that mixes with inflowing lake water at the eastern reach of the outer bay. The distribution of volatile contaminants is governed by the thermal regime of the receiving waters. During the summer months, the effluent plume wedges between the thermocline and epilimnion, mixing into the surface waters as the distance from the input source increases. In the fall, the ...
Several lanthanide shift reagents (LSR) were synthesized from praseodymium, europium, dysprosium, and terbium using ethylenediaminetetraacetic acid, trans-1,2-diaminocyclohexane-N,N,N[prime],N[prime]-tetraacetic acid, and diethylenetriaminepentaacetic acid for the purpose of separating overlapping [sup 31]P FT-NMR spectral signals of dissolved organic phosphorus compounds present in concentrated lake-water samples. The extent of change in signal position and line width of several known phosphorus compounds dissolved in pure water was examined as a function of solution pH and the molar ratio of LSR to phosphorus. Praseodymium ethylenediaminetetraacetate (PrEDTA) was determined to be the most effective LSR. Concentrated lake-water samples mixed with PrEDTA were examined with [sup 31]P FT-NMR. The use of PrEDTA provided separation of overlapping signals, indicated that phosphorus compounds were becoming isolated from the solution environment ...
A stable isotope mass-balance of dissolved inorganic carbon during a blue-green algae bloom in a softwater lake demonstrates that at low partial pressure of carbon dioxide there must be a large net negative carbon isotope fractionation between atmospheric CO/sub 2/ and the CO/sub 2/ absorbed by lake water at pH = 9.5. Chemical enhancement of CO/sub 2/ invasion at high pH by the reaction CO/sub 2/ + OH/sup -/ ..-->.. HCO/sub 3//sup -/ at large apparent film thicknesses may result in carbon isotope fractionation approaching that for a hydroxide solution. This phenomenon, coupled with a decrease in the photosynthetic fractionation, forced the surface water of a softwater lake to achieve increasingly negative delta /sup 13/C values during an algal bloom, which is in the opposite sense to the trend that results from photosynthesis under less extreme conditions. This and other similar systems must operate under non-equilibrium ...
A trans-uranium (TRU) fuel should be manufactured and loaded in transmutation systems in order to transmute the long-lived TRU nuclides into short-lived ones. However, since all of the TRU nuclides are not completely transmuted in one cycle lifetime in transmutation systems, the spent TRU fuel has to be treated to recover the long-lived radionuclides or fuel matrix materials. One concept to manufacture TRU fuel for transmutation is to recover uranium from TRU and molten salt. If this type of fuel is adopted for transmutation, uranium could also be an objective material to be recovered and recycled. Since electrowinning is a promising technology to be employed for the recovery of uranium from fuel materials, some experimental work of electrowinning using anode of Cd-Li alloy was carried out in this study. The basic salt chosen was a mixture of LiCl-KCl which has an eutectic point at 357 .deg. C.
A trans-uranium (TRU) fuel should be manufactured and loaded in transmutation systems in order to transmute the long-lived TRU nuclides into short-lived ones. However, since all of the TRU nuclides are not completely transmuted in one cycle lifetime in transmutation systems, the spent TRU fuel has to be treated to recover the long-lived radionuclides or fuel matrix materials. One concept to manufacture TRU fuel for transmutation is to recover uranium from TRU and molten salt. If this type of fuel is adopted for transmutation, uranium could also be an objective material to be recovered and recycled. Since electrowinning is a promising technology to be employed for the recovery of uranium from fuel materials, some experimental work of electrowinning using anode of Cd-Li alloy was carried out in this study. The basic salt chosen was a mixture of LiCl-KCl which has an eutectic point at 357 .deg. C
The solubilities of plutonium and uranium have been determined for alkaline salt solutions having compositions which bound those which will be processed in the In-Tank Precipitation (ITP) process. Loadings of plutonium and uranium onto monosodium titanate (MST) have been determined at temperatures bounding those expected to occur during ITP and using a salt solution which was determined to have the maximum solubility for uranium and plutonium. Fissile loadings increase with decreasing amounts of MST in contact with the salt solutions saturated in plutonium and uranium. At MST concentrations bounding those which are planned for the ITP process, expressions for the maximum loadings (wt %) are determined to be 0.29 - 0.20x[MST] for plutonium and 1.8 - 0.29x[MST] for uranium, where [MST] is the concentration of MST in grams/liter. These expressions are valid over the range of MST ...
In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with ...
Radon concentration measurements in atmosphere were taken in years from 1997 to 1999 in Milan and at pre-alpine sites located north of Lombardy. In this paper the results of measuring campaigns and a comparison of radon levels observed in the hilly area north of the town and on the pre-Alps are reported. The general criteria of the measurements and the interpretative models of radon concentration are presented. The Lake Maggiore area shows evidence of a great nocturnal stability and frequent formation of Nocturnal Stable Layer. The peculiar findings in the high altitude stations confirm the use of radon as an indicator of atmospheric dispersion of pollutants in an area with complex orography. The afternoon minimum values are concordant for the different stations: this implies a remixing in afternoon hours over the whole area investigated.
A distributed watershed hydrologic model soil and water assessment tool (SWAT, 2000 Version) was applied to simulate stream flow and nutrient loadings (including total nitrogen (TN) and total phosphorus (TP)) in Gucheng Lake Basin, which is located in the lower reach of Yangtze River Basin. Model parameters related to stream flow and nutrient loadings were calibrated and validated by the observed value, and the simulation showed that the simulated values were reasonably comparable to the observed data, suggesting the validity of SWAT model. The simulated surface runoff and nutrient yield between two stages, viz. 1981-2000 and 1951-1960, were compared, basically considering land reclamation in the mid-1970s. The result indicated that, the average annual runoff and output of TN and TP in 198...
One hypothesis for the decline of the North American greater (Aythya marila) and lesser (A. affinis) scaup population is that contaminant burdens acquired on wintering or staging areas impair reproduction or cause lethal or sublethal health effects. Recent studies have found increased selenium (Se) concentrations in scaup but have focused on the fall and spring staging periods. From January to March 2006 and December to March 2006 and 2007, we analyzed liver tissues collected from greater scaup wintering in western Lake Ontario for 16 trace elements. We also measured Se concentrations in greater scaup blood and Dreissenid mussel tissue. Se was the only trace element that occurred at increased concentrations (>10??g/g liver dry weight) in a substantial proportion (99%) of greater scaup live...
Zooplankton tolerant to ultraviolet radiation (UVR) could be indirectly affected by UVR through interactions with UV-sensitive species in the same ecosystem. In Lake Giles, Pennsylvania, USA, the calanoid copepod Leptodiaptomus minutus is more UVR tolerant than the cohabiting species Daphnia catawba and Cyclops scutifer. We asked whether L. minutus is affected by UV-induced mortality of a food competitor (D. catawba) or a predator of its nauplii (C. scutifer). We conducted two in situ enclosure experiments with six treatments: L. minutus alone, L . minutus + Daphnia and L. minutus + Cyclops in the presence and absence of UVR. There were few differences in survival among treatments in Experiment 1, which had enhanced food and a cumulative UVR (320 nm) dose of 9.3 kJ m-2. In Experiment 2, wh...
Periphyton is typically a heterogeneous assemblage of filamentous and single celled photoautotrophic and heterotrophic micoorganisms suspended in a mucopolysaccharide matrix which they produce. By definition, the assemblage is attached to a substratum such as rock, sediment, or plant in an aquatic environment. Microtechniques with high spatial and temporal resolution are required to define metabolic interactions among the heterotrophic and autotrophic constituents, and between periphyton and its environment. This study used oxygen sensitive microelectrodes with tip diameters of < 30 m to investigate the effects of photosynthesis and respiration on the oxygen dynamics of several diverse periphyton communities both in situ and in laboratory microcosms. A novel flow-through system that utilized TSP radiotracer and that permitted manipulation of the velocity, flushing rate, and oxygen concentration of overlying water was developed to investigate the role of photosynthetic oxygen ...
This report consists of appendices A-F containing the biological data which were collected from Lake Roosevelt, Washington. The data are to be used in the design of a computer model that would predict biological responses of reservoir operations as part of the System Operation Review program. Major components of the model included: Quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times.
Numerous studies have shown that large, herbivorous waterfowl can reduce quantity of aquatic plants during the breeding or wintering season, but relatively few document herbivory effects at staging areas. This study was done to determine if feeding activities of tundra swans (Cygnus columbianus columbianus) and Canada geese (Branta canadensis) had a measurable additive influence on the amount of aquatic plants, primarily muskgrass (Chara vulgaris), wild celery (Vallisneria americana), and sago pondweed (Potamogeton pectinatus), removed during the fall migration period at Long Point, Lake Erie, Ontario. Exclosure experiments done in fall 1998 and 1999 showed that, as compared to ducks and abiotic factors, these two large herbivorous waterfowl did not have any additional impact on above or b...
To mitigate damages caused by agricultural runoff, private lake owners' associations are paying for inlake and instream pollution abatement measures and on land-conservation practices. This phenomenon supports the notion that individuals who benefit from improved water quality should be willing to pay part of the abatement costs. The research suggests that on land-conservation measures can substantially reduce sediment delivery at low cost. The Sediment Economics (SEDEC) model was modified and then used to select and to site management systems that achieved stated sediment goals at least cost. Other resource policies such as T value, no-till, and contouring were compared with the least-cost frontier and shown to be more costly. The noncropland areas substantially reduced sediment delivery to water channels and lowered abatement costs. Further research is needed for long-range watershed-planning models such as SEDEC.
We discuss geochemical and sedimentological characteristics of 12 tephra layers, intercalated within the finely laminated sediments of Lake Van. Within the about 15 kyr long sediment record studied, volcanic activity concentrated in the periods 2.6-7.2 and 11.9-12.9 kyr B.P. Concentrations of 25 elements provide the geochemical fingerprint of each tephra layer and allow comparison to literature values of potential source volcanoes such as Mts. Nemrut and Suephan. The youngest two tephra layers (and probably also the other three ashes from the 2.6-7.2 kyr B.P. eruptions) originate from the Nemrut volcano. The source of the older tephra (11.9-12.9 kyr B.P.), however, remains unidentified.
The Quantou Formation recovered by CCSD-SK-Is borehole (China Cretaceous Continental Scientific Drilling-SongkeI-the south borehole) is 132.07 m long and the recovery of cores is 100%. The sequence and process of lithology-lithofacies and cyclostratigraphy are revealed by a detailed core description. Nine rock types and three kinds of sedimentary facies including meandering river, shallow lake, and delta front are recognized from the drilling core, there are ten sedimentary microfacies, which are point bar, natural levee, crevasse splay, crevasse channel, floodplain, flood lake, distributary mouth bar, interdistributary bay, mudstone of still water, and turbidite. The Quantou Formation represents seventy-six meter-scale cycles (sixth-order cycle), twenty-five fifth-order cycles, eight four...
The decrease and subsequent lack of recovery of the North American scaup population has increased concerns about contaminants acquired during migration. We collected 189 fall- and spring-migrant lesser (Aythya affinis) and greater scaup (A. marila) on the lower Great Lakes (LGL) to determine if organic contaminants and trace elements in scaup livers were increased and to evaluate sources of variation in selenium (Se) burdens. We found that all organic contaminants were below toxic levels. Of 18 trace elements, only Se was detected at increased (>10-ppm dry-mass) levels. Se in lesser scaup increased but remained constant in greater scaup throughout fall; levels were increased in 14% of lesser scaup and 46% of greater scaup. During spring, Se increased in lesser scaup but decreased slightly ...
SummaryThis paper examines the sensitivity and uncertainty of evaporation estimates from Nasser Lake, south of Egypt using data collected at the floating station Raft, 2km upstream of the Aswan High Dam, and 12 evaporation models. Based on their approach the evaporation models were ranked in five classes, respectively the Bowen ratio energy budget (BREB) approach, three energy-aerodynamic based methods, a mass transfer method, two temperature and five solar radiation-temperature approaches. State dependent parameter models were used to estimate the sensitivity indices of the different evaporation estimation methods at daily and monthly frequencies. A drastic reduction in the cost of the sensitivity analysis was obtained when coupled with efficient sampling methods, producing quasi-Monte Ca...
To reconstruct the profiles of heavy metal levels in the South Ocean ecosystem of Antarctica, the concentrations of lead (Pb), copper (Cu), arsenic (As), cadmium (Cd), and zinc (Zn) in seal hairs and lake sediments spanning the past 1500?years from Fildes Peninsula of King George Island and in weathering lake sediments from Nelson Island of West Antarctica were determined. The lead contents in the seal hairs and the weathering sediments show a sharp increase since the late 1800s, very likely due to anthropogenic contamination from modern industries. After the 1980s, the Pb content in seal hairs dropped by one-third, apparently due to the reduced usage of leaded gasoline in the Southern Hemisphere. Copper arises mainly from the weathering process, and its level may be substantially affected...
This paper provides both a detailed history of environmental change in the Sierra Nevada over the past 1,800?years and evidence for climate teleconnections between the Sierra Nevada and Greenland during the late Holocene. A review of Greenland ice core data suggests that the magnitudes of abrupt changes in temperature and precipitation increased beginning c. 3,700 and 3,000?years ago, respectively. Precipitation increased abruptly 1,300?years ago. Comparing paleotemperature data from Cirque Peak, CA with paleoprecipitation data from Pyramid Lake, NV suggests that hot temperatures occurred at the beginnings of most severe droughts in the Sierra Nevada over the past 1,800?years. Severe fires and erosion also occurred at Coburn Lake, CA at the beginning of all severe droughts in the Sierra Ne...
Radon concentration measurements in atmosphere were taken in years from 1997 to 1999 in Milan and at pre-alpine sites located north of Lombardy. In this paper the results of measuring campaigns and a comparison of radon levels observed in the hilly area north of the town and on the pre-Alps are reported. The general criteria of the measurements and the interpretative models of radon concentration are presented. The Lake Maggiore area shows evidence of a great nocturnal stability and frequent formation of Nocturnal Stable Layer. The peculiar findings in the high altitude stations confirm the use of radon as an indicator of atmospheric dispersion of pollutants in an area with complex orography. The afternoon minimum values are concordant for the different stations: this implies a remixing in afternoon hours over the whole area investigated.
Various remedial measures have been tried to lower radon levels in buildings in Uranium City. The methods used are source material removal, passive ventilation of crawl spaces, sub-floor ventilation, complete epoxy coating of the entire basement, sealants for floor-wall joints and cracks in basements, electrostatic precipitators, mechanical ventilation, and sealing and grouting concrete block plenums in basement walls. The type and condition of structures encountered in Uranium City as well as the relative isolation of the town indicate that mechanical ventilation is the most long-term cost-effective method.
The technology developed here will exploit the ability of microorganisms to remove dissolved metals from aqueous solutions. Microbial sorbents for uranium will be immobilized biosorbents will be deployed ex situ within flow-through reactors for the continuous or semicontinuous treatment of recovered wastewaters. The proposed technology will primarily be applied within a pump-and-treat process using immobilized biosorbents for the large-scale, long-term remediation of uranium-laden surface water or groundwater impoundments (environmental restoration). The technology may be equally useful as an ``end-of-pipe`` treatment of process effluents (waste management). Successful operation of this process will achieve immobilization of the targeted waste and accompanying volume reduction.
The method of reactivity determination using noise analysis correlation measurements with /sup 252/Cf was used to determine the reactivity for subcritical 17.77-cm-dia uranium (93.2 wt percent /sup 235/U) metal cylinders with reactivities as low as 25 dollars. Far subcritical tests were performed with right circular cylinders of uranium metal for which the subcritical reactivity was known from other inverse kinetics and prompt neutron decay constant measurements.
Study of the rate of dissolution in simulated lung fluid of uranium from 3 different ore matrices and from refined uranium dioxide in an essentially all teflon extraction apparatus; the rate of dissolution of thorium from a nickel metal/2 percent thoria mixture; the effect of neutron irradiation of the studied materials upon the dissolution rates; and the adsorptions of the radioisotope tracers barium 133 (substitute for radium), lead 203 and thorium 234 upon the extraction system components.
Major contributions during this contract period have been in developing an analytical procedure for Pu measurement, and in applying the developed procedures to determining the plutonium concentration and distribution in coral from the Bikini Atoll. In conjunction with these contributions, measurements using the fission-track method have been made of the uranium distribution and concentrations in several carbonate samples from drill cores obtained from the Runit Island Enewetak Atoll. Petrographic studies on these drill core samples have been made to correlate the uranium data with the mineralogical data.
Major contributions during this contract period have been in developing an analytical procedure for Pu measurement, and in applying the developed procedures to determining the plutonium concentration and distribution in coral from the Bikini Atoll. In conjunction with these contributions, measurements using the fission-track method have been made of the uranium distribution and concentrations in several carbonate samples from drill cores obtained from the Runit Island Enewetak Atoll. Petrographic studies on these drill core samples have been made to correlate the uranium data with the mineralogical data. (auth)
The emission of light charged particles from heavy fragments of uranium fission induced by 153-MeV protons is studied. The probability of their emission is 2.7 x 10{sup - 2} per fission event. It is found that these particles affect the distribution of angles of fragment divergence and the angular distribution of heavy fragments with respect to the primary-proton beam. Experimental results suggest that the preequilibrium emission of particles is correlated with fission. Two mechanisms of interaction between 153-MeV protons and uranium nuclei are considered. 13 refs., 10 figs., 1 tab.
The Purex process and the fluorescence spectrometry are first recalled, then uranyl fluorescence is studied in a pure nitric medium without other elements to establish a theoretical model, allowing the description of uranium fluorescence signal with a general equation. The influence of different parameters (temperature, inhibitors, dynamic quenching of iron and cerium) is investigated to develop the model. A quantitative analysis method without addition of reagents is proposed to validate the model.
... shrouded in secrecy in 2008, Iraq sold its stock of 550 metric tons (in 3,500 barrels) of apparently commercial-grade yellow cake (milled uranium ...
The impacted armor targets used in testing high density armor-piercing ammunition containing depleted uranium (DU) are subject to disposal as low-level radioactive waste. Because of the costs associated with disposal of the entire armor plate and the limited use of secured commercial sites in the future, the U.S. Army is seeking to identify and evaluate new technologies for decontaminating these armor plates. The objectives of this Phase I SBIR program are two-fold, namely: to develop a selective solvent that can decontaminate impacted armor targets containing DU for disposal or recycle, and to identify and characterize technologies that can remove depleted uranium from the solvent for solvent recycle and uranium recovery for easier hazardous-waste disposal.
Thin passive layers of uranium nitride were formed by nitriding pure metallic uranium in non-equilibrium, low pressure radio-frequency plasma of nitrogen. Plasma nitriding at low substrate temperature of 230 C-250 C was found to cause the formation of adherent layers of uranium sesquinitride ({alpha}-U{sub 2}N{sub 3}) which provide a considerable protection against hydrogen attack. The characteristics of these passivation layers were determined by X-ray diffraction and Auger electron spectroscopy. The incipient hydriding kinetics of the plasma-treated samples were compared with those of untreated and nitrogen-ion implantation ones, utilizing a hot-stage microscope that was monitored continuously with a TV camera and videotape. (orig.)
Chronic exposure to uranium compounds such as UO{sub 2} and U{sub 3}O{sub 8} led to the development of a methodology, based on the recommendation of ICRP, involving four main steps: the measurement of the uranium concentration and the particle size distribution at the workstation, the assessment of physico-chemical properties of the compound, the study of in-vitro solubility using a chemical test and the monitoring of workers. Results and comments on UO{sub 2} and U{sub 3}O{sub 8} are given. (author)
The temperature and concentration dependence of the kinetics of uranium(VI) ions adsorption onto activated charcoal from aqueous solutions has been studied. The adsorption proceeds via a rather fast stage followed by a slower one, with activation energies of 5.41 and 17.46 kJ . mol[sup -1] respectively. The diffusion of uranium ions into the pores of the activated charcoal controls the kinetics of adsorption which follows the Langmuir isotherm equation in the concentration range studied. The adsorption equilibrium constant k[sub c] has been derived at temperatures between 283 K and 323 K as well as [Delta] G, [Delta] H and [Delta] S. The results indicate that the adsorption of uranium ions on activated charcoal is an endothermic process. (orig.)
Evaluations were done to determine conditions that could permit nuclear criticality with fissile uranium in low-level waste (LLW) facilities and to estimate potential radiation exposures to personnel if there were such an accident. Simultaneous hydrogeochemical and nuclear criticality studies were done (1) to identity realistic scenarios for uranium migration and concentration increase at LLW disposal facilities, (2) to model groundwater transport of uranium and subsequent concentration via sorption or precipitation, (3) to evaluate the potential for nuclear criticality resulting from potential increases in uranium concentration over disposal limits, and (4) to estimate potential radiation exposures to personnel resulting from criticality consequences. This paper presents the details of the radiation exposure calculations relying on the conditions as determined from the preceding studies detailed in a ...
Decontamination and decommission activities related to the Molten Salt Reactor Experiment (MSRE) involve the trapping and recovery of radiolitically generated uranium hexafluoride and fluorine. Although fission product radiolysis was known to generate F{sub 2}, the formation of UF{sub 6} and its transport from the fuel salt was unexpected. Some of these gaseous radiolysis products have been moving through the gas piping to a charcoal bed since the reactor was shut down in 1969. Current and planned remediation and clean-up activities involve the trapping of the gaseous products, deactivation and treatment of the activated charcoal bed, stabilization and reconditioning of the fuel salt, and recovery of the uranium. The chemical aspects of these processes, including radiolytic generation mechanisms, reactions between uranium hexafluoride and fluorine and trapping materials such as activated charcoal, activated alumina, and ...
Water-based epoxy sealants were examined during a 2-year period to determine their effectiveness as barriers to radon release in uranium mines. Radon emanation rates from uranium ore samples were monitored for extended periods in the laboratory before and after sealant application. Reduction of radon flux due to the coating of lab samples was approximately 80 percent. Test chambers in a dormant uranium mine were monitored to determine both short and long-term barrier effectiveness. These field studies of the sealants indicated reductions greater than 50 percent relatively soon after application and nearly 75 percent more than 1 year later. An unexpected complication to early monitoring in the form of a large radon emanation increase, believed due to added moisture, is discussed.
The methods are described of determining natural radionuclides, viz., thorium, uranium, radium, radon, polonium, actinium, and protactinium. The analysis is also described of ores, rocks, minerals, water, air. (M.D.).
This report attempts to bring together available information on the coal deposits of Antarctica and discuss factors that would be involved if these deposits were to be explored and mined. Most of the reported principal coal deposits in Antarctica lie generally within the Transantarctic Mountains: the majority are of Permian age and are present in the Victoria Group of the Beacon Supergroup. Several other deposits have been recorded in East Antarctica and in the Antarctic Peninsula, including minor occurrences of Mesozoic and Tertiary coal and carbonaceous shale.
In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was ...
The possibilities to grow isolated structures of complex oxides by pulsed laser deposition through stencils were investigated. A stencil consisting of a SiN membrane with apertures of several hundred nanometers embedded in a Si chip is placed in front of a heated substrate (up to 750 degrees Celsius). Deposition through these apertures results in resistless, direct patterning by local deposition of complex oxides like ferroelectric Lead Zirconate Titanate. The created isolated structures were analyzed by AFM imaging. Under-deposition, in this work called broadening, is inevitable during stencil deposition and is depending on deposition parameters, especially pressure. Different causes of broadening are mapped and discussed.
In an effort to minimize the distortion of bearing steel rings during the production process, 100Cr6 steel billets are spray formed with a unique cooling control system to control the cooling and solidification behavior of the deposits. Effects of heating around the deposits, gas cooling at the substrate bottom and the gas flow over the deposits are investigated both by numerical simulation and experiment. Porosity profiles and microstructures of spray formed bearing steel are examined and evaluated. The investigation results show that the thermal boundary conditions of the deposits play important roles on the cooling and solidification behavior of the deposits, especially at the deposit periphery. Porosity in the 100Cr6 bearing steel deposit can be reduced significantly with the special cooling control system.
Indian PHWRs are designed to operate with natural uranium (NU) as the main fuel. Earlier in the initial fresh core, to achieve flux flattening and hence to operate the reactor at design rated power, limited number of depleted uranium bundles were loaded in the central portion of the core. Presently even in fresh core about 40 % of the core is loaded with depleted uranium bundles (?0.6 wt % 235U) from the consideration of conserving the natural uranium fuel. This is achieved by loading most of the depleted bundles in the peripheral locations of the channels. Successful operation with large number of DU bundles in the fresh core has been proven in MAPS - 2 and MAPS - 1cores after EMCCR as well as in TAPP - 4. In these three reactors 100 % FP was possible even with 40 % DU bundles in the core. In TAPP-4 and 3 initial core, depleted bundles of 0.36 wt % 235U are also loaded to conserve the depleted bundles ...
YBa_2Cu_3O_7_-_x thick films have been deposited on silver sheets and MgO single crystals by spray pyrolysis. Film texture is related to film thickness and sintering temperature. The X-ray intensity ratio of the 005 peak to the 110 peak is higher for thin films deposited at the higher temperatures. However, elevated temperatures promote copper diffusion and second-phase formation in films deposited on silver. Films deposited on MgO can have larger grain sizes and are more oriented than those deposited on silver.
Energy deposition process by relativistic fast electrons produced by ultra-intense laser pulses is discussed. The process is calculated with a two dimensional Fokker-Planck simulation code including binary and collective collisions coupled with electromagnetic field. We focused on Velocity Distribution Function (VDF) dependence in the simulation. The results show that the spread angle of the fast electrons distribution affects energy deposition area and deposited energy is concentrated in the vicinity of the propagation axis of the fast electrons. It may be also suggested that self-pinch effect of a fast electron beam causes large deposition energy. (author)
A new magnetic macroparticle filter design consisting of two 90{sup o} filters forming an S-shape is described. Transport properties of this S-filter are investigated using Langmuir and deposition probes. It is shown that filter efficiency is product of the efficiencies of two 90{sup o} filters and the deposition rate is still acceptably high to perform thin film deposition. Films of amorphous hard carbon have been deposited using a 90{sup o} filter and the S-filter, and macroparticle content of the films are compared.
Results are given for deep-level petroleum and gas drilling probes in various coastal zones of Southern Sakhalin covering the Poronai depression and the Aniv Bay trough. The exploratory probes indicate that the Middle Miocence deposits of the Boundary trough contain commercial-size deposits of petroleum, that commercial-size gas deposits are in the upper Myocene deposits of the Aliv Bay trough, and that the upper Cretaceous and Cenozoic deposits of the eastern section of Southern Sakhalin lack folded deformations. 7 references, 2 figures.
The application of a Compact Airborne Spectrographic Imager to assessment and monitoring of lakes in a lignite open cast mining area in central Germany is described. The imager was used in combination with additional ground experiments, such as field spectroscopy and water sampling. The spectral characteristics of an instrument under development for monitoring geochemical and hydrological processes are presented. Summary form only.
Spectral absorption properties of total suspended matter (TSM) and colored dissolved organic matter (CDOM) are important for the use of the bio-optical model to estimate water quality parameters. This study aims to investigate the variation in the absorption coefficients of TSM and CDOM of inland waters. A total of 92 water samples were collected from Shitoukoumen Reservoir and Songhua Lake in Northeast China, analyzed for TSM and Chl-a, and measured for the absorption coefficient of TSM, CDOM and total pigments using a laboratory spectrophotometer. The absorption coefficient of TSM has been decomposed for phytoplankton and inorganic sediments. The results show that for Shitoukoumen Reservoir, CDOM has strong absorptions with shallow absorption slopes (i.e., the coefficient S in a(?)=a(?0)exp[-S(?- ?0)]) and large absorption at 355 nm; and for Songhua Lake, CDOM follows similar spectral absorption curves but less variation in the S value. The ...
This report contains studies which are part of the Bonneville Power Administration`s program to protect, mitigate, and enhance fish and wildlife affected by the development and operation of hydroelectric facilities on the Columbia River and its tributaries. Attention is focused on population monitoring studies in the Sawtooth Valley Lakes. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.
Field studies were conducted May 28-June 1, 1979, to determine the chemical composition and physical behavior of discharges from an offshore gas drilling rig in the central basin of Lake Erie. The drilling operation was observed for four days, from rig jackup to the circulation of mud through the borehole after drilling had been completed. Resuspension studies using nephelometry, supplemented with chemical analyses, indicated little resuspension of lake bottom materials or release of metals to the water column during rig jack-up. Portions of the turbidity plumes generated during drilling were buoyant. Three surface turbidity plumes were mapped with nephelometry to a point at which particulate concentrations reached background levels in the Lake. Detectable plumes were approx. 400 to 1500 m in length and had maximum widths < 230 m. A chemical survey conducted in the plume during early gas shows indicated that discharged ...
Assessing the potential environmental and human effects of deploying renewable energy on private and public lands, along our coasts, on the Outer Continental Shelf (OCS), and in the Great Lakes requires a new way of evaluating potential environmental and human impacts. The author argues that deployment of renewables requires a framework risk paradigm that underpins effective future siting decisions and public policies.
DescriptionPhytoplankton is the collective name given to the microscopic floating plants in seas and lakes. Under certain conditions, the abundance of phytoplankton as a whole or of one or more species in particular, can reach a magnitude at which it is visible through discolouration of the sea. Some of these blooms because of the colour of the water have been called 'Red Tides'. Blooms of some 300 species of the phytoplankton are known as Harmful Algal Bloom (HAB) species in recognition of their poten [continued...
Results are presented from a series of studies conducted at the Department of Energy (DOE) Savannah River Plant (SRP) with the NASA Airborne Oceanographic Lidar (AOL). These studies included a topographic survey of a {approximately}1000 acre lake basin (presently designated L Lake) which had been excavated for use as a cooling pond for L Reactor; a study of the movement of discharged cooling water in Pond C and the warm arm of Par Pond using Rhodamine WT dye as a tag; initial baseline studies of the vegetation cover of the Steel Creek corridor (through which the outflow of L Lake is carried to the Savannah River); and a demonstration of potential forestry applications of the AOL. These investigations were conducted over a 3-day period in June 1985. The AOL is an advanced airborne laser system capable of making temporal or time history measurements of laser backscatter (bathymetry mode) or spectral measurements of laser ...
The understanding of fission product deposition in realistic steam generator conditions is needed for release estimates in PSA studies, and for the design of efficient accident management procedures. This is considered very important because primary-to-secondary leakages risk dominant sequences in many plants. Furthermore, the decay heat of the fission product deposits adds to the thermal load to the steam generator tubes also in other sequences, especially in case of cold leg leakages. This brings out the concern of induced steam generator tube ruptures in cases, where the steam generators are initially intact. The experimental data showed that the highest deposited fraction within the tubes were found in cases with lowest flow velocities. The minimum value of the deposited fraction was observed at intermediate flow velocities. With these relatively low Reynolds numbers, the results calculated with ...
The understanding of fission product deposition in realistic steam generator conditions is needed for release estimates in PSA studies, and for the design of efficient accident management procedures. This is considered very important because primary-to-secondary leakages risk dominant sequences in many plants. Furthermore, the decay heat of the fission product deposits adds to the thermal load to the steam generator tubes also in other sequences, especially in case of cold leg leakages. This brings out the concern of induced steam generator tube ruptures in cases, where the steam generators are initially intact. The experimental data showed that the highest deposited fraction within the tubes were found in cases with lowest flow velocities. The minimum value of the deposited fraction was observed at intermediate flow velocities. With these relatively low Reynolds numbers, the results calculated with ...
The harmful effect of phosphate in yellow cake on the TBP purification process and its removal methods are dealed with. The reason of more uranium loss in residue was analyzed. The harmful effect of phosphate on TBP extraction efficiency and operaton of extraction column was discussed. The limit value of uranium concentration in digestion solution was presented. For TBP purification process, the presence of phosphate in yellow cake does more harm than good. (authors)
Biosorption of uranium by residual biomass from The Old Bushmill`s Distillery Co. Ltd., Bushmills, Co. Antrim, Northern Ireland, following exposure to short and intense electric pulses has been examined. The biomass was prepared from the distillery spent wash and consisted of non-viable yeast and bacterial cells. As shown previously, untreated biomass had a maximum biosorption capacity of 170 mg uranium/g dry weight biomass. When biosorption reactions were placed between two electrodes and exposed to electric pulses with field strengths ranging from 1.25-3.25 kV/cm at a capacitance of 25 {mu}F, biosorption increased from 170 mg of uranium to 275 mg uranium/g dry weight biomass. The data were obtained from biosorption isotherm analyses and taken as the degree of biosorption at residual uranium concentrations of 3 mM. In addition, when the capacitance of the electric pulses increased ...
Stability constants for uranium-tetracycline complexes were determined by the method of average number of ligands, the method of limiting values, the method of two parameters and the method of weighted least squares. Solvent extraction technique was used to obtain experimental data. (author). 10 refs.; 5 figs.
In response to a need of the safeguards community, we have begun an evaluation effort to upgrade the recommended values of the prompt neutron emission multiplicity distribution, P/sub nu/ and its average value, nubar. This paper will report on progress achieved thus far. The evaluation of the uranium, plutonium, americium and curium nuclide's nubar values will be presented. The recommended values will be given and discussed. 61 references.
This paper reviews the mill flowsheet applied at the SOMAIR (Societe des Mines de l'Air) uranium mill in Niger. It focuses on the yellow cake quality improvements achieved by molybdenum and zirconium elimination through double yellow cake precipitation in tanks at first stage and through size/density control in a fluidized bed precipitator at second stage. Water saving aspects in the plant are also presented. (author)
This paper reviews the mill flowsheet applied at the COMINAK uranium mill (Compagnie Miniere d'Akouta) in Niger. For ore treatment, it focuses on the major improvements to the operations using sulfonitric pugging and solids/liquid separation using belt filter double filtration after leaching. The precipitation circuits have been improved with molybdenum elimination through caustic washing of the yellow cake. (author)
To the crushed ore leaching is applied. The resulting solid-liquid mixture is fed to a hydro-cyclon grading facility; here the superfine grain is separated before the concentrated mixture can be filtered or centrifuged. The grading is done in several steps. From the liquid, ultimately ridded of the solid, uranium compounds are precipitated and the yellow cake is obtained. (DG).
The optical properties of uranium monochalcogenides and monopnictides are discussed in terms of their electronic structure. A comparison is made with corresponding rare earth compounds. It is shown that there are close similarities to mixed valence CeN. the results support the occurrence of a dip in the density of d states near Esub(F), where the f density of states has its maximum. Empirical energy level schemes are derived which are found to agree with the existing information from XPS measurements and recent theories. (orig.).
> Develoopments which have imporved fuel core quality and reduced production costs are described. These developments in the melting and casting of uranium ingots arei modification of the crucible and knockout-slide assembly, substitution of uncoated crucibles for coated crucibles, and substitution of a one-piece gun barrel mold for a vertically split mold. (N.W.R.)
This ISB in conjunction with the new TSRs, will provide the required basis for interim operation or restrictions on interim operations and administrative controls for the Facility until a SAR is prepared in accordance with the new requirements. It is concluded that the risk associated with the current operational mode of the Facility, uranium closure, clean up, and transition activities required for permanent closure, are within Risk Acceptance Guidelines. The Facility is classified as a Moderate Hazard Facility because of the potential for an unmitigated fire associated with the uranium storage buildings.
... Research Center, Washington DC May 23 BBC NEws: US used Nuclear Weapons in Afghanistan Jalalabad: New reference levels based on recent samples show uranium levels 45 times normal. New bioassay studies identify uranium internal contamination in Spin Gar (Tora Bora) area and the City ...
Observed 7-eV satellites in the XPS spectra of UGa_2 and other B-group compounds are shown to be due to two-hole final states as confirmed by existing Auger data. The presence of these satellites is an indication for a weak fd hybridization and, when compared to uranium--transition-metal compounds, increased 5f localization.
The purpose of this study is to investigate the possibility of verifying depleted uranium (DU), natural uranium (NU), low enriched uranium (LEU) and high enriched uranium (HEU) by a developed digital gamma-gamma coincidence spectroscopy. The spectroscopy consists of two NaI(Tl) scintillators and XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results demonstrate that the spectroscopy provides an effective method of "2"3"5U and "2"3"8U quantification based on the count rate of their gamma-gamma coincidence counting signatures. The main advantages of this approach over the conventional gamma spectrometry include the facts of low background continuum near coincident signatures of "2"3"5U and "2"3"8U, less interference from other radionuclides by the gamma-gamma coincidence counting, and region-of-interest (ROI) imagine analysis for uranium enrichment ...
In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of ...
A numerical investigation of the mixing of gaseous uranium and hydrogen inside an open-cycle gas core nuclear rocket engine (spherical geometry) is presented. The gaseous uranium fuel is injected near the centerline of the spherical engine cavity at a constant mass flow rate, and the hydrogen propellant is injected around the periphery of the engine at a five degree angle to the wall, at a constant mass flow rate. The main objective is to seek ways to minimize the mixing of uranium and hydrogen by choosing a suitable injector geometry for the mixing of light and heavy gas streams. Three different uranium inlet areas are presented, and also three different turbulent models (k-var-epsilon model, RNG k-var-epsilon model, and RSM model) are investigated. The commercial CFD code, FLUENT, is used to model the flow field. Uranium mole fraction, axial mass flux, and radial mass flux ...
The electrometallurgical treatment process described in this paper builds on our experience in treating spent fuel from the Experimental Breeder Reactor (EBR-II). The work is also to some degree, a spin-off from applying electrometallurgical treatment to spent fuel from the Hanford single pass reactors (SPRs) and fuel and flush salt from the Molten Salt Reactor Experiment (MSRE) in treating EBR-II fuel, we recover the actinides from a uranium-zirconium fuel by electrorefining the uranium out of the chopped fuel. With SPR fuel, uranium is electrorefined out of the aluminum cladding. Both of these processes are conducted in a LiCl-KCl molten-salt electrolyte. In the case of the MSRE, which used a fluoride salt-based fuel, uranium in this salt is recovered through a series of electrochemical reductions. Recovering high-purity uranium from an aluminum-matrix fuel is more challenging ...
The use of borated plaster to isolate uranium (93.2 wt % /sup 235/U) metal was studied in a series of subcritical experiments with uranium metal cylinders (7.0 in. diam, 2.0 in. thick) and slabs (approx.1.4 x approx.5.4 x approx.10.1 in. dimensions). In the cylindrical experiments, the thickness of borated plaster was varied up to 10 in. and the subcriticality measured using the /sup 252/Cf-source-driven neutron noise analysis method. In the experiments with the uranium slabs, an array of slabs 3 wide and 8 high was assembled in steps to demonstrate the subcriticality of this array with 3.75-in.-thick borated plaster as an isolating material between all uranium slabs. In the slab experiments, both noise analysis and source neutron multiplication measurements were performed. Before assembly of the slab array the presence of boron in the plaster was verified by neutron transmission and gamma-ray ...
Finland has some 10 million hectares of peatland, accounting for almost a third of its total area. Macroclimatic conditions have varied in the course of the Holocene growth and development of this peatland, and with them the habitats of the peat-forming plants. Temperatures and moisture conditions have played a significant role in determining the dominant species of mire plants growing there at any particular time, the resulting mire types and the accumulation and deposition of plant remains to form the peat. While in a natural state the mires of Finland have functioned as carbon dioxide sinks throughout the post-glacial period, but the ditching of peatland for forestry and agriculture, amounting to some 5,7 million hectares in Finland, has affected their water balance, especially over the last hundred years, and has thereby altered the quantity and species composition of the mire vegetation. The invasion of trees and woody plants to replace the typical mire plants ...
Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on featured or non-featured silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedure. Only silicon substrates exposed and reactive to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to selectively deposit metal films in small features. SFID may also provide a new method to fabricate palladium silicide in small features or to metallize porous silicon.
In this paper we demonstrate the electrodeposition of nickel, a common ferromagnetic material, in various magnetically desirable shapes including nanowires, nanoparticles and highly faceted shells. In order to obtain three dimensional mesostructures, the electrochemical deposition of nickel was performed on highly oriented pyrolytic graphite (HOPG) under different electrolyte composition and deposition potential conditions. Under potentiostatic deposition at one distinct potential negative with respect to the reversible potential of nickel, three stages of nucleation and growth take place leading to a complex morphology of deposits. However, dual-pulse potential deposition and electrodeposition in low pH solutions causing hydrogen evolution, lead to nickel deposits in the form of nanowires...
A ternary nickel-base alloy Ni-W-B has been developed for surface corrosion and wear resistance to replace chromium plating, which uses environmentally hazardous solutions. The deposition conditions used an alkaline bath and insoluble anodes. The as-deposited alloy typically contains 40 wt% W and 1 wt% B and has an amorphous or partially amorphous structure. These deposits compare favorably with hexavalent chromium deposits in throwing power, color uniformity, and reflectivity. The corrosion resistance of Ni-W-B alloy was compared with hexavalent chromium and electroless nickel deposits in a variety of acids, including hydrochloric, sulfuric, fluoroboric, and phosphoric. In all cases, best results were obtained with the Ni-W-B deposits.
Biosorption equilibrium, kinetics and thermodynamics of binding of uranium ions to Cystoseria indica were studied in a batch system with respect to temperature and initial metal ion concentration. Algae biomass exhibited the highest uranium uptake capacity at 15 deg. C at an initial uranium ion concentration of 500 mg l{sup -1} and an initial pH of 4. Biosorption capacity increased from 198 to 233 mg g{sup -1} with an decrease in temperature from 45 to 15 deg. C at this initial uranium concentration. The Langmuir isotherm model were applied to experimental equilibrium data of uranium biosorption depending on temperature. Equilibrium data fitted very well to the Langmuir model C. indica algae in the studied concentration range of Uranium ions at all the temperatures studied. The saturation type kinetic model was applied to experimental data at different ...
Analytical relations are obtained for estimating how the distributions of temperature and heat flux vary along a steam-generating tube and how the steam-generator power output reduces due to formation and accumulation of deposits.
Analytical relations are obtained for estimating how the distributions of temperature and heat flux vary along a steam-generating tube and how the steam-generator power output reduces due to formation and accumulation of deposits.
The reactive evaporation process was successfully used to deposit films of the A-15 Nb_3Ge phase. This is the first report, to the best of our knowledge, illustrating the use of such processes for the deposition of A-15 compounds. In this process, niobium vapors from an electron-beam-heated evaporation source react with germane gas introduced into the vacuum chamber at low partial pressures (approximately 10"-"4 Torr) to produce Nb_3Ge deposits. The process variables studied were the deposition temperature, the niobium-to-germanium impingement ratio on the substrate and the plasma-enhanced deposition, in this case the activated reactive evaporation process. At low deposition temperatures (below 450"0C) the deposit is amorphous (or microcrystalline) and can be crystallized to the Nb_3Ge phase by heat treatment, e.g. at 850"0C for 1 h in ...
This report results from a contract tasking Eindhoven University of Technology as follows: The contractor will investigate the plasma treatment of surfaces and plasma enhanced deposition using EUT's cascade arc source as the basis for this effort.
Pulsed laser deposition (PLD) is known for its capacity to reproduce a target composition on a substrate. The authors have used this deposition technique to produce thin films of transition metal chalcogenides. However, the deposits were always deficient in Te relative to the starting material (composed by a refractory metal (niobium) and a chalcogene (tellurium)). Variations of the interreticular distances have been observed with respect to fluence and substrate temperature. The authors show that spatial composition of the films is determined by a degree of crystallinity of deposit and by the reaction of formation of Te{sub 2} molecule within laser induced plume. Two kinds of deposits have been obtained: Nb{sub 5}Te{sub 4}-type thin films which have a one-dimensional structure and NbTe{sub 2}-type thin films which have a two-dimensional structure. While NbTe{sub 2} films have been ...
Inactive cells of Rhizopus arrhizus have been documented to exhibit a high thorium biosorptive uptake (170 mg/g) from aqueous solutions. The mechanism of thorium sequestering by this biomass type was investigated following the same method as for the uranium biosorption emchanism. The thorium sequestering mechanism appeared somewhat different from that of uranium. Experimental evidence is presented which indicates that, at optimum biosorption pH (4), thorium coordinates with the nitroge of the chitin cell wall network and, in addition, more thorium is adsorbed by the external section of the fungal cell wall. At pH 2 the overall thorium uptake is reduced. The kinetic study of thorium biosorption revealed a very rapid rate of uptake. Unlike uranium at optimum solution pH, Fe/sup 2 +/ and Zn/sup 2 +/ did not interfere significantly with the thorium biosorptive uptake capacity of R. arrhizus.
The microdynamics of soliton waves and localized modes of nonlinear vibrations of the acoustic and optical types in uranium nitride has been investigated. It has been shown that, with an increase in the excitation energy in the spectral gap between the bands of optical and acoustic phonons, the energies of solitons increase, whereas the energies of local modes decrease. The previously experimentally observed unidentified quasi-resonant features, which shift in the gap with variations in the temperature, can represent the revealed soliton waves and local modes. The microdynamics of heat conduction of uranium nitride has been studied for the stochastic generation of soliton waves and local modes in the case of spatially distant energy absorption. The thermal conductivity coefficient determin...
This study started with a comprehensive and critical review of the published information of relevance to the different methods to produce uranium dioxide from raw materials. we have chosen this method 'flame denitration' or flame process to produce Uo_2. from its compounds, uranyl nitrate Uo_2 ( NO_3) _2 .6H_2o) prepared from raw uranium 'yellow cake'. This method in short produces uranium dioxide from aqueous uranyl nitrate by contacting the atomized liquid which has 40 #mu# in diameter with hot reducing gases (butane and oxygen mixture) till we obtain a suitable and yellow red colour light for the flame and this is a prof that there is carbon monoxide and hydrogen, the temperature of the reactor at is least 950 degree C.
Using the Laser-Fluorescence technique, an investigation was made, adopting the standard mix method, on trace uranium concentrations in hot spring water and geothermal water from Lishan region, and in tap water from some major cities in Shanxi province. Totally 40 samples from 27 sites were investigated. Measurement showed that the tap water contains around 10"-"6 g/L of uranium, whose concentrations in both hot spring water and geothermal water are 10"-"5 g/L. Most of samples are at normal radioactive background level, some higher contents were determined in a few samples
Lead is contained as trace element in uranium ores and propagates throughout the production process to intermediate products like yellow cake or uranium oxide. The lead isotopes in such material originate from two sources: natural lead and radiogenic lead. The variability of the isotopic composition of lead in ores and yellow cakes was studied and the applicability of this parameter for nuclear forensic investigations was investigated. Furthermore, the chemical impurities contained in these materials were measured in order to identify characteristic differences between materials from different mines. For the samples investigated, it could be shown, that the lead isotopic composition varies largely from mine to mine and it may be used as one of the parameters to distinguish between materials of different origins. Some of the chemical impurities show a similar pattern and support the conclusions drawn from the lead isotope data. (orig.)
The design, construction and operation of a pilot plant are often important stages in the development of a project for the production of uranium concentrates. Since building and operating a pilot plant is very costly and may not always be required, it is important that such a plant be built only after several prerequisites have been met. The main purpose of this guidebook is to discuss the objectives of a pilot plant and its proper role in the overall project. Given the wide range of conditions under which a pilot plant may be designed and operated, it is not possible to provide specific details. Instead, this book discusses the rationale for a pilot plant and provides guidelines with suggested solutions for a variety of problems that may be encountered. This guidebook is part of a series of Technical Reports on uranium ore processing being prepared by the IAEA's Division of Nuclear Fuel Cycle and Waste Management. 42 refs, 7 figs, 3 tabs.
From their genesis by weathering and sedimentation, bauxites, the principal aluminium ores, contain appreciable amounts of uranium and thorium. High resolution gamma spectrometry with a high purity germanium detector was used for an analysis of four industrially used bauxites from Gondama, Sierra Leone; Boke, Guinea; Weipa, Queensland, Australia; Gove, Northern Territory, Australia. Significant differences in uranium to thorium ratios and in activities of the uranium and thorium daughters were observed for the four bauxites. It was found that the bauxite from Gondama, Sierra Leone has an activity of only 10% compared with the others. Red mud tailings from such a bauxite may well be used as an additive to bricks, which is now illegal for normal red mud from more active bauxites. (author).
From their genesis by weathering and sedimentation, bauxites, the principal aluminium ores, contain appreciable amounts of uranium and thorium. High resolution gamma spectrometry with a high purity germanium detector was used for an analysis of four industrially used bauxites from Gondama, Sierra Leone; Boke, Guinea; Weipa, Queensland, Australia; Gove, Northern Territory, Australia. Significant differences in uranium to thorium ratios and in activities of the uranium and thorium daughters were observed for the four bauxites. It was found that the bauxite from Gondama, Sierra Leone has an activity of only 10% compared with the others. Red mud tailings from such a bauxite may well be used as an additive to bricks, which is now illegal for normal red mud from more active bauxites. (author).
In situ treatment has been proposed as a remediation alternative for surface water and groundwater contaminated with uranium and nitrate as a result of former waste disposal practices in the S-3 Ponds. Interceptor trenches containing reactive media have been proposed to treat groundwater, and constructed wetlands and/or algal mats are potential alternatives for treating surface water. This report presents the results from testing of ten different reactive media, and combinations of media, that are candidates for use in the proposed interceptor trenches to remove uranium and nitrate from groundwater. It also presents the results of testing and evaluation of algal mats and wetlands for removing uranium and nitrate from surface water.
Categorization is complete. Samples 11-3-1 (NSR-F-270409-01) and 11-3-2 (NSR-F-270409-02) are depleted uranium powders of moderate purity (#approx#65-80 % U). The uranium feed stocks for 11-3-1 and 11-3-2 have both experienced a neutron flux (as demonstrated by the presence of "2"3"2U). Sample 11-3-3 is indistinguishable from a natural uranium ore concentrate of moderate purity (#approx#70-80% U). Two anomalous objects (11-3-1-4 and 11-3-2-5) were found in the material during aliquoting. These objects might be valuable for route attribution.
Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.
Studies of asphalt emulsion sealants have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to less than background levels. Field tests at the tailings pile in Grand Junction, Colorado confirmed that an 8-cm admix seal containing 22 wt % asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and conpacted, overburden was applied over the seal to protect the seal from ultraviolet degradation. 14 figures.
Adult and newborn rats were exposed to "2"3"9PuO_2 aerosols of four different size distributions. Rats of both ages were killed at intervals between 1 hr and 60 days postexposure. There were marked age- and particle-related size differences in deposition, although retention was similar throughout. The differences in deposition are attributable to relatively greater deposition of larger particles in the upper respiratory tracts of newborns.
... analyzer section for angle resolved measurements, and a thin film evaporator with a quartz crystal microbalance to measure the mass deposition. ...
A compact cesium deposition system was used for direct deposition of cesium atoms and ions onto the inner surface of the 1/3 scale Hydrogen Negative Ion Source for the LHD-NBI system. A small, well defined amount of cesium deposition in the range of 3-200 mg was tested. Negative ion extraction and acceleration were carried out both in the pure hydrogen operation mode and in the cesium mode. Single Cs deposition of 3-30 mg to the plasma chamber have produced temporary 2-5 times increases of H-yield, but the yield was decreased within several discharge pulses to the previous steady-state value. Two consecutive 30 mg depositions done within a 3-5 hours/60 shot interval, produced a similar temporary increase of H-beam, but reached a larger H-yield steady-state value. Deposition of larger 0.1-0.2 g Cs portions with a 20-120 hours/150-270 shot interval improved the ...
The hydrogen evolution reaction (HER) was studied on Ni-P{sub x} electrodes containing 8 to 16 weight percent P prepared by potentiostatic deposition. The amount of P in the alloy varied with deposition potential. The activity of the electrodes was dependent on the P concentration, and the formation of a passive film. Cyclic voltametry was used to study the removal of this film. 3 refs.
The question about expanding the boundaries of the open pit mining method is examined. The use of methods which consider the advantages of open and underground mining operations with their joint use in horizontal and evenly dipping deposits will make it possible to objectively select the mining method, to expand the range of use of open pit mining operations in the deposits of the Far North and provide an improvement in the technical and economic indicators of mineral extraction.
Amyloid-β (Aβ) deposits have been identified as key players in the progression of Alzheimer’s disease (AD). Recent evidence indicates that the deposits probably precede...Full Text Available
This report measured the rate of isothermal deposition of sub-micron particles of magnetite onto the surface of Alloy 800 at pH of 4.2-9.3 at Re=10,000 and a fluid temperature of 25C. Deposition is modelled as a two-step process, the transport of particles to the surface region followed by attachment to the surface.
Water-resources data for the 1993 water year for Texas are presented in four volumes, and consist of records of stage, discharge, and water quality of streams and canals; and stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 3 contains records for water discharge at 134 gaging stations; stage only at 1 gaging stations; stage and contents at 13 lakes and reservoirs; water quality at 81 gaging stations; and data for 30 partial-record and 4 flood-hydrograph partial-record stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations; crest-stage and flood-hydrograph partial-record stations, reconnaissance partial-record stations, and low-flow partial-record stations.
Mining operations took place at the Sullivan Mine, located at Sullivan, Abitibi, Quebec between 1930 and 1967 and generated large quantities of tailings. These tailings now represent a waste rock pile in the shape of a delta on the shore of De Montigny Lake. The area covers approximately 50 hectares. When the waste rock pile was first established, several terrestrial and aquatic ecosystems were lost forever. In addition, the very nature of the tailings, combined to the action of the wind and lake, further slow the natural site regeneration. The Ministere des Ressources naturelles du Quebec (Quebec Natural Resources Department) asked Les Consultants en Environnement Argus to prepare a site remediation plan to stimulate the natural regeneration of the ecosystems. It would enable the local fauna to resume its occupation of the territory, while ensuring its proper integration in the environment. The authors described in detail the proposed plan ...
The Coastal Zone Sector of the Canadian Climate Impact and Adaptation Research Network (C-CIARN) was established to address concerns regarding climate change in coastal areas. Coastal zones are sensitive to increases in air, sea and ground temperatures as well as to variations in sea level, precipitation, ice thickness, and storm intensity. This report presents the results of a workshop which focused on how coastal communities will be affected by climate induced water level changes, particularly sea-level rise on ocean coasts and decreasing lake levels in the Great Lakes. The workshop addressed issues such as the effects of changing water levels on coastal infrastructure, utilities, community development, and the implications of changing water levels to human safety, cultural resources, tourism, and insurance. The workshop reviewed the current state of understanding on water level fluctuations resulting from climate change. It also identified ...
Kaiser Alumina and Chemical Co. impounds red mud, the byproduct of alumina production, behind levees. Kaiser recognizes that this action cannot be maintained indefinitely. Therefore, a project is in progress to produce useful products from red mud that increase the profitability of the Gramercy facility. Before products could be developed, an obstacle had to be overcome. The annual rainfall in South Louisiana prevents evaporative drying of the mud lakes. Innovative methods were applied to dry the lake mud. Two products have been developed. A daily landfill cover and an absorbant, which are marketed under the Cajunite{trademark} banner. Both products are currently being tested by potential customers at their sites. Environmental concerns were addressed during development. Extensive TCLP results show no metal leachate problems. All pilot tests and plant trials received LADEQ approval. Products that are under development include levee core, road ...
This is the annual report of the Radiological and Environmental Division of the Argonne National Laboratory for 1982. Studies of the effects of ozone on crop growth and yield have been carried out by the Terrestrial Ecology Group for winter wheat and for sorghum. The Microcosms for Acid Rain Studies (MARS) facility was completed in the early summer. Controlled investigations of plant and soil responses in acid rain were initiated with crop plants grown in two different midwestern soil types. The Transuranics Group has found that the solubility and adsorptive behavior of plutonium previously observed at fallout concentrations in natural waters (approx. 10/sup -16/ to 10/sup -18/ M) is applicable at plutonium concentrations as high as 10/sup -8/ M. The Lake Michigan eutrophication model has been adapted to operation in a Monte Carlo mode. Simulations based on yearly phosphorus loadings and winter conditions were selected at random from prescribed probability ...
To reconstruct the profiles of heavy metal levels in the South Ocean ecosystem of Antarctica, the concentrations of lead (Pb), copper (Cu), arsenic (As), cadmium (Cd), and zinc (Zn) in seal hairs and lake sediments spanning the past 1500 years from Fildes Peninsula of King George Island and in weathering lake sediments from Nelson Island of West Antarctica were determined. The lead contents in the seal hairs and the weathering sediments show a sharp increase since the late 1800s, very likely due to anthropogenic contamination from modern industries. After the 1980s, the Pb content in seal hairs dropped by one-third, apparently due to the reduced usage of leaded gasoline in the Southern Hemisphere. Copper arises mainly from the weathering process, and its level may be substantially affected by climatic conditions. The concentrations of Cd, As, and Zn do not show any clear temporal trends.
The purpose of SEADEX was to acquire a comprehensive, high-quality data base for evaluating models of dispersion within coastal zones, it secondary objective was to provide data to help determine which meteorological measurements are most appropriate for emergency preparedness at nuclear power plant sites. The study was conducted in the vicinity of Kewannee, Wisconsin, on the western shore of Lake Michigan. This report describes the design of the study and the data base resulting from it. Both a gas tracer (SF/sub 6/) and a particulate tracer (oil fog) were used. (ACR)
Recent research developments in common-pool resource models emphasize the importance of links with ecological systems and the presence of non-linearities, thresholds and multiple steady states. In a recent paper Kossioris et al. (2008) develop a methodology for deriving feedback Nash equilibria for non-linear differential games and apply this methodology to a common-pool resource model of a lake where pollution corresponds to benefits and at the same time affects the ecosystem services. This paper studies the structure of optimal state-dependent taxes that steer the combined economic-ecological system towards the trajectory of optimal management, and provides an algorithm for calculating such taxes.
Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.
The actual cost of constructing the LNG facility was about $589 million, an increase of approximately 258% over the $164 million cost estimate approved by the Federal Power Commission (FPC) in 1977. According to reports submitted by Trunkline LNG, the reasons for the increases included extensive modifications to plant design to ensure safe and reliable construction and greater operating efficiency and compliance with state and federal regulations. Also, extension beyond the original estimated completion date, various labor problems, and general inflation resulted in increased labor and interest costs.
Taconite tailings and their component asbestiform minerals in Lake Superior water had no demonstrable effect on the chronic toxicity of cadmium to the flagfish, Jordanella floridae. Maximum acceptable toxicant concentrations determined in life cycle tests, where effects on survival, growth, reproduction, and bioconcentration were used as endpoints, were between 3.3 to 7.4, 3.0 to 6.5, and 3.4 to 7.3 micrograms cadmium/liter at 0.004, 0.08, and 0.95 mg/liter taconite tailings concentrations, respectively.
Homestake Ore from the Ambrosia Lake District of New Mexico was treated in the Alkaline Leach-- Filtration Pilot Plant at Grand Junction, Colorado. Detailed information on grinding, leaching, flltration, and precipitation in connection with the processing of this ore is given. Autoclave leaching and continuous yellow cake precipitation were employed. The circuit liquors contnined organic material that was detrimental to clariflcation and precipitation and the results show that ihe ore was amenable to the Alkaline Leach--Filtration process only if a special additive was used. (auth)
This book is based on a new method published in U.S. Geological Survey Circular 994 and is the second assessment made in accordance with the 1984 Memorandum of Understanding between the U.S. Department of the Interior and the U.S. Department of Energy. The first estimate was published as U.S. Geological Survey Open-File Report 80-2. The endowment estimates are reported for 26 areas in the following 1{degrees} {times} 2{degrees} guadrangles: Grand Canyon, Marble Canyon, Williams, Flagstaff, Prescott, Holbrook, and St. Johns, Ariz., and Cedar City, Utah. The total uranium endowment is about eight times larger than reported in 1980 by the Department of Energy. The Grand Canyon region has the potential of becoming the second most important domestic uranium producer after the most production San Juan Basin uranium region in New Mexico.
This study evaluates the degree to which surface impoundments at licensed facilities comply with significant changes in NRC requirements initiated by enactment of EPA's final environmental standards for uranium recovery facilities (40 CFR Part 192). Impoundment liner requirements, ground-water protection standards, ground-water monitoring and corrective action programs, and site closure standards are the most significant regulatory modifications. The compliance status of 30 conventional mills and 31 in-situ mines is determined from a review of Nuclear Regulatory Commission and agreement state docket files through November, 1983. Results of this review show that a majority of conventional uranium mill tailings management systems are deficient with respect to liner requirements for new impoundments or proposed expansions to existing impoundments, as well as with respect to some aspects of ground-water monitoring and compliance programs. ...
This report presents geologic considerations that are pertinent to the Remedial Action Plan for Slick Rock mill tailings. Topics covered include regional geology, site geology, geologic stability, and geologic suitability.
The production of the uranium mine Zirovski Vrh ceased in 1990. The main remaining problem of the remadiation are mine and mill tailings. The uranium mine Zirovski Vrh has one mill tailings site Borst and one waste pile Jazbec. According to the Act on protection against ionising radiation and nuclear safety which was adopted by the Parliament in 2002, they are classified as radiation facilities. Slovenian Nuclear Safety Administration (SNSA) is authorised for issuing a mandatory consent to mining work. The SNSA prepared the initial proposal of content of the safety report for the mine waste pile Jazbec. In 2005, according to the detailed content of this document, the public company Zirovski Vrh Ltd prepared the safety report which was examined by an authorised expert for radiation and nuclear safety. After a careful revision of the safety evaluation report, the consensus for mining work shall be issued by the SNSA. After finishing the mining ...
The storage of aluminum-clad fuel and target materials in the L-Disassembly Basin at the Savannah River Site for more than 5 years has resulted in extensive pitting corrosion of these materials. In many cases the pitting corrosion of the aluminum clad has penetrated in the uranium metal core, resulting in the release of plutonium, uranium, cesium-137, and other fission product activity to the basin water. In an effort to characterize the extent of corrosion of the Mark 31A target slugs, two unirradiated slug assemblies were removed from basin storage and sent to the Savannah River Technology Center for evaluation. This paper presents the results of the metallography and photographic documentation of this evaluation. The metallography confirmed that pitting depths varied, with the deepest pit found to be about 0.12 inches (3.05 nun). Less than 2% of the aluminum cladding was found to be breached resulting in less than 5% of the ...
Individual monitoring of personal exposure to inhalation of uranium oxides throughout the manufacture of fuel for pressurized water reactor (PWR) includes lung gamma-spectrometry, fecal analysis and urine analysis. Examination of the results shows the following: internal exposure is the consequence of repeated intake incidents as revealed by early peaks of urinary and particularly fecal elimination; a shift is often observed with the results of aerosol concentration measured through air collectors; the measured variations of uranium lung incorporations are relatively fast (apparent mean period 165 d). Correct evaluation of the effective dose equivalent from inhalation requires further information concerning the aerosol size distribution at work stations, the physico-chemical characteristics of the product leading to an estimate of its actual biological solubility, and the measurement of the fraction of aerosol liable to intake with an ...
The biological accumulation of heavy metals and cesium, strontium, and uranium in plants is discussed. The role of nutrient deficiencies and foliar treatments of manganese and iron compounds is described.
A simple sample decomposition and laser fluorimetric determination of uranium at trace level is reported in certain refractory minerals, like ilmenite, rutile, zircon and monazite; environmental samples viz. soil and sediments; industrial waste materials, such as, coal fly ash and red mud. Ilmenite sample is decomposed by heating with ammonium fluoride. Rutile, zircon and monazite minerals are decomposed by fusion using a mixture of potassium bifluoride and sodium fluoride. Environmental and industrial waste materials are brought into solution by treating with a mixture of hydrofluoric and nitric acids. The laser induced fluorimetric determination of uranium is carried out directly in rutile, zircon and in monazite minerals and after separation in other samples. The determination limit was 1 #mu#g x g"-"1 for ilmenite, soil, sediment, coal fly ash and red mud samples, and it is 5 #mu#g x g"-"1 for rutile, zircon and monazite. The method is also ...
Nuclear Fuel Plant (FCN) is a facility that produces fuel bundles of CANDU-6 type for the CANDU nuclear power plant. Only natural and depleted uranium in bulk and itemized form are present as nuclear materials in this facility. Uranium and wastes from the plant are handled, processed, treated and stored throughout the entire facility. The nuclear materials with natural and depleted uranium are entirely under nuclear safeguards. The amount of uranium present in the plant in different forms and activities together with zircaloy, beryllium and other hazardous substances, wastes, explosive materials at high temperatures, etc. lead to special measures undertaken by Nuclear Safety Department (DNS) to ensure nuclear safety. Different aspects of safety are continuously monitored in the plant: operational safety, industrial safety, radiological safety, labour safety, informational safety. The emergency ...
Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited ...
Bi-U mixed oxides were synthesized by two methods and characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The samples were tested for the catalytic oxidation of carbon monoxide by oxygen. A stepwise redox mechanism consistent with the kinetic results is proposed. (orig.).
This regulatory guide describes methods acceptable to the NRC staff for calculating radon fluxes through earthen covers and for calculating the resulting minimum cover thickness needed to meet NRC and EPA standards. The guide also suggests methods for obtaining the various parameters used in calculating the radon fluxes and earthen cover thicknesses and suggests default values for certain parameters. This regulatory guide is applicable to active uranium tailings sites. The NRC staff is using the methods stated in this guide as a basis for review and concurrence of DOE remedial action plans for inactive sites. The guidance is intended to be used for calculating radon flux attenuation by earthen uranium mill tailings covers. The parameter values and examples presented are limited to earthen cover materials, but the diffusion theory and the methods presented are also applicable to man-made materials. Detailed supporting information for calculating ...
This regulatory guide describes methods acceptable to the NRC staff for calculating radon fluxes through earthen covers and for calculating the resulting minimum cover thickness needed to meet NRC and EPA standards. The guide also suggests methods for obtaining the various parameters used in calculating the radon fluxes and earthen cover thicknesses and suggests default values for certain parameters. This regulatory guide is applicable to active uranium tailings sites. The NRC staff is using the methods stated in this guide as a basis for review and concurrence of DOE remedial action plans for inactive sites. The guidance is intended to be used for calculating radon flux attenuation by earthen uranium mill tailings covers. The parameter values and examples presented are limited to earthen cover materials, but the diffusion theory and the methods presented are also applicable to man-made materials. Detailed supporting information for calculating ...
A method of the correction for sample self attenuation used in segmented gamma scanner (SGS) is described. The method of calibration for assaying the uranium and plutonium contents of each category of heterogeneous process residues and wastes in nuclear facilities is studied. The effect of variable measurement parameter on measurement results is also studied. The measurement results of SGS assay is compared with that of the destructive assay (DA), which is aimed at evaluating SGS method for assaying uranium and plutonium content in process residues and wastes. The deviation of two assay results is 3.6%. The SGS assay results and DA assay results both are coincided well in error limits. Four category of heterogeneous process residues and wastes in nuclear facilities have assayed successfully in physical inventory. The uncertainty of measurement results for uranium and plutonium content in process residues and wastes is 5% ...
The Secure Automated Fabrication (SAF) line, an automated and remotely controlled manufacturing process, is scheduled for startup in 1987 and will produce mixed uranium/plutonium oxide fuel pins for the Fast Flux Test Facility (FFTF). The application of robotics in the fuel fabrication and supporting operations is described.
Magnetic coupling between two or more metal centers is an important facet of d- and f-block transition metal chemistry due to its implications in chemical bonding. With respect to actinide metals, magnetic coupling between polymetallic actinide centers is less well-known. Of the few documented examples, only one bimetallic uranium(V) complex, [(MeC{sub 5}H{sub 4}){sub 2}U]{sub 2}[{mu}-1,4-N{sub 2}C{sub 6}H{sub 4}] (1), has unequivocally demonstrated antiferromagnetic coupling. This complex employs a {pi}-conjugated 1,4-phenylenedimide ligand system which bridges the two f{sup 1}-metal centers and enables antiferromagentic coupling between unpaired f-e1ectrons residing in a {pi}-symmetry orbital. In this communication, we report the synthesis of a dimeric bis(imido) uranium(V) iodide complex and demonstrate with magnetic susceptibility measurements and density functional theory (DFT) calculations that the f{sup 1}-uranium ...
The Abrasive Waterjet Cutting process was evaluated to determine if the equivalent could be utilized for cutting uranium metal at the Feed Materials Production Center (FMPC). In the process, a thin stream of ultrahigh pressure water carried grit material through a designated piecepart. In order to be acceptable for use at the FMPC, the equipment must be cost effective, minimize waste, and be adaptableto operating in an enclosure, and improve health and safety conditions. Observation of the cutting process showed that health and safety aspects could be optimized with an enclosed ventilated system. Also the equipment can be easily automated. The cutting action produced sparks similar to the sparks caused by a grinding operation. The sparks are captured in a water container under the workpiece that not only catches the sparks, but also serves to dissipiate the stream of water and residues produced by the cut. Metallographic tests performed on the cut surface of the ...
A sensitivity study has been done to determine the composition of DUPIC fuel from the viewpoint of neutronics fuel design. The spent PWR fuel compositions were generated and fissile contents adjusted by blending fresh uranium after mixing two spent PWR fuel assemblies. The {sup 239}Pu and {sup 235}U enrichments of DUPIC fuel were adjusted by controlling the amount of fresh uranium feed and the ratio of slightly enriched and depleted uranium in the feed uranium. Based on the material balance calculation, it is recommended that DUPIC fuel composition be such that spent PWR fuel utilization is more than 90%. A sensitivity study on the temperature reactivity coefficient of DUPIC fuel and shown that it is desirable to increase the {sup 239}Pu and {sup 235}U contents to reduce both the fuel and coolant temperature coefficients. On the other hand, refueling simulations of the DUPIC core have shown that the ...
Tree swallows were used to evaluate movement and potential impacts of contaminants from sediments in Newton Creek (diesel range organics: DROs) and Sheboygan River (PCBs), tributaries to Lake Superior and Lake Michigan, respectively. Contaminated sites occurred along the course of each river, while reference sites were located upstream or on a nearby river. Productivity was monitored and eggs, day 1 nestlings, and day 12 nestlings were collected from each nest. Whole body or egg homogenates were analyzed for PCBs or DROs. EROD activity in livers from day 12 nestlings is being determined for both PCB and DRO exposures. In the Newton Creek study, hatching success was similar for DRO and reference sites. DROs were detected in gastrointestinal tracts of 1 nestling from the reference and 1 from the contaminated site. DROs were not detected in any egg samples. In the Sheboygan River study, hatching success rates differed between 1 reference and 1 ...
Estimated kokanee (Oncorhynchus nerka) abundance in Lake Pend Oreille was 4.3 million during September 1986. This estimate was similar to 1985 and indicates continued suppression of the kokanee population since initial decline in the late 1960s. Atypically high survival of wild fry resulted in similar fry recruitment in 1986 as 1985, whereas hatchery-reared fry contributed only 8% to total fry recruitment as a result of low post-release survival (3%). Fry released into the Clark Fork River from Cabinet Gorge Hatchery had very low survival during emigration to Lake Pend Oreille, resulting from poor flow conditions and potentially high predation. Fry survival during emigration was twice as high during nighttime flows of 16,000 cfs than 7,800 cfs. Emigration also was faster during higher flows. Several marks were tested to differentially mark fry release groups to help determine impacts of flow and other factors on fry survival. Survival of fry ...
Precambrian gneisses in the San Bernardino Mountains were first identified and described in the vicinity of Baldwin Lake by Guillou (1953). Five lithologic units mappable at 1:24,000 scale are recognized: biotite [+-] muscovite quartzofeldspathic gneiss, amphibolite, pyroxene metagabbro, augen gneiss, and biotite [+-] muscovite granitic gneiss. Baldwin gneiss with this L Baldwin Lake, the gneissic fabric is rotated toward the northwest, subparallel to the Doble fault. Along this fault, Baldwin gneiss is structurally underlain by overturned Paleozoic quartzite and marble (Zabriskie Quartzite and Carrara Formation). Regional relations suggest that the Doble fault is a northeast-directed basement thrust fault of pre-Late Cretaceous age, and may be contemporaneous with late Paleozoic deformation and metamorphism of Paleozoic rocks further west in the range. Field relations suggest that Baldwin gneiss in its type area largely retains Proterozoic ...
Lacustrine rocks are a significant component of many rift-valley sequences. Comparisons of both active and ancient rift valleys indicate that the lacustrine facies are commonly rich in organic matter and may be important sources for oil. For example, Holocene sediments in Lake Tanganyika and Cretaceous lacustrine rocks in west Africa contain as much as 12% and 20% TOC, respectively. The Newark Supergroup contains abundant lacustrine rocks. The widespread occurrence of black shales, the general similarity to known organically rich rift systems, and a few isolated geochemical analyses have caused some speculation about the potential of the Newark Supergroup to be an effective source of oil and gas. Sufficient geochemical analyses are available from lacustrine rocks in the Newark, Connecticut, and Deep River basins to evaluate their potential as hydrocarbon sources. In general, both the quantity and quality of organic matter in these rocks are less than that required ...
Effective doses from {sup 210}Po intake with caribou meat were determined for human residents in Baker Lake and Snowdrift in the Northwest Territories of Canada and compared to doses calculated from reported {sup 210}Po tissue activities in Alaskan and British residents. Effective doses were calculated to separate body tissues, using ICRP 60 human weighting factors and the ICRP 30 metabolic model for {sup 210}Po. Baker Lake and Alaskan effective doses were similar at 0.4 mSv y{sup {minus}1} and slightly higher than Snowdrift doses (0.3 mSv y{sup {minus}1}). Alaskan tissue activities indicated higher effective doses to liver, bone surfaces and red marrow and lower doses to spleen than the {sup 210}Po metabolic model (ICRP 1979a) predicts. Effective doses to Baker Lake and Snowdrift caribou and wolves, calculated from tissue activities, ranged from 7-20 mSv y{sup {minus}1} using human weighting factors for comparison to human ...
Full text: The isotopic assay instrument under development at Pacific Northwest National Laboratory (PNNL) is capable of rapid prescreening to detect small and rare particles containing high concentrations of uranium in a heterogeneous sample. The isotopic measurement concept is based on laser vaporization of solid samples followed by sensitive isotope-specific detection using either uranium atomic fluorescence emission or uranium atomic absorbance. Both isotopes are measured concurrently, following a single ablation laser pulse using two external-cavity violet diode lasers. The simultaneous measurement of both isotopes enables the correlation of the fluorescence and absorbance signals on a shot-to-shot basis. This measurement approach demonstrated negligible channel crosstalk between isotopes. Scanning the heterogeneous samples provides high-resolution imagery of sample isotopic fluorescence and absorbance. Isotopically ...
This paper discusses essentially the role of WDXRFS based multi element data in uranium exploration, with special reference to India. The state of art MagiX-PRO WDXRFS with 4 kW end window x-ray tubes has been used in the present study as an indispensable geo-analytical tool for the analysis of major and selected trace elements at ppm to percentage level, with high precision and relatively better accuracy
Measurements of the photon angular distribution of Radiative Electron Capture into the M shell have been performed with He-like uranium ions in the range 110-140 MeV/u. In addition, L REC was studied at a projectile energy of 140 MeV/u. In both cases, the experimental data show an asymmetry around 90 and agree well with a fully relativistic theory. (orig.) 15 refs.
The purpose of the Ocean FUSRAP Program, which began in March 1981, is to assess the technical, environmental, and institutional feasibility of disposing, in the ocean and on the ocean floor, of FUSRAP waste which contains traces of natural radioactive materials. The initial planning has focused on the Middlesex, New Jersey, Sampling Plant site and surrounding properties, which contain on the order of 100,000 metric tons of material. The Belgian Congo uranium ore and other uranium ores used by the United States were handled at the sampling plant site and have since been removed.
This paper presents calculations of the {sup 252}Cf-source-driven noise analysis measurements for subcritical highly enriched uranium metal cylinders using the Monte Carlo code MCNP-DSP. This code directly calculates the noise analysis data from the {sup 252}Cf- source-driven noise analysis method for both neutron and gamma ray detectors. Direct calculation of experimental observables by the Monte Carlo method allows for the benchmarking of the calculational model and the cross sections and for determining the bias in the calculation.
The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.
The use of uranium mill tailings in the foundations of dwellings has resulted in indoor radon progeny concentrations and gamma exposures in excess of levels presently allowed for the general public. An account is given of the applications of an epoxy coating on the indoor faces of the concrete foundations of three buildings in Grand Junction, Colorado. Epoxy barriers were shown to be effective for preventing radon influx into structures. Gamma exposure rates must be analyzed to ensure that buildup behind the barrier will not introduce an unacceptable gamma exposure level. The use of a sealant is especially economical in situations where structural integrity may be jeopardized by physical removal of uranium mill tailings. (author).
Five nomographs have been prepared that facilitate the estimation of cover thickness and cover material volume for the Uranium Mill Tailing Remedial Action Program. Key parameters determined include the cover thickness with either a surface radon flux or a boundary radon air concentration criterion and the total volume of cover material required for two different treatments of the edge slopes. Also included in the engineering guide are descriptions and representative values for the radon source term, the diffusion coefficients and the key meteorological parameters. 16 refs., 7 figs., 2 tabs.
This paper reports that, to obtain better simulation results for a Canada deuterium uranium (CANDU) reactor operation, a new simulation method is developed that uses actual detector readings as a correction factor. Detector readings from a CANDU reactor are used to correct the calculated flux distribution during core calculation iterations. A suitable function is found to describe the relationship between the detector flux and the fluxes of mesh points around the detector. The new simulation method is tested by performing numerical calculations for the Wolsung reactor (a CANDU-600). The results show that the new method predicts the core state more accurately with fewer iterations.
The author presents a new technique for production of yellow cake with double precipitation, thus solving a series of problems for precipitating uranium with traditional double precipitation. The new technique can not only remove ferric ions and sulfate radicals but also make solid-liquid separation easy, utilize effectively the sulfuric acid produced in ferric ions precipitation process, and increase uranium concentration of leaching liquor. To take it as producing yellow cake will save investment, simplify operation, and cut down the consumption of raw materials and energies. It is more competitive than ion-exchange or solvent extraction in the process of extracting-purifying and preparing yellow cake.
Understanding the erosion and deposition rates in a small watershed is important for designing soil and water conservation measures. The objective of this study is to estimate the net soil loss and gain at points with various land use types and landform positions in a small watershed in the Sichuan Hilly Basin of China by the 137Cs tracing technique. Among various land use types, the order of erosion rate was bare rock > sloping cultivated land > forest land. The paddy field and Caotu (a kind of cultivated land located at the foot of hills) were depositional areas. The erosion rate under different landform was in this order: hillside > saddle > hilltop. The footslope and the valley were depositional areas. The 137Cs technique was shown to provide an effective means of documenting the spatial distribution of soil erosion and deposition within the small watershed.
Pd/sub 2/Si formation at the Pd-Si interface induced by irradiation with ions having a wide range of nuclear energy of deposition density has been investigated. It is found that the thickness of the silicide layer formed by irradiation is proportional to the ion fluence for irradiation with ions having low energy-deposition densities, while it is proportional to the square root of the fluence for irradiation with ions having energy-deposition densities. The results indicate that Pd/sub 2/Si formation is reaction limited when the energy-deposition density at the interface is low and is diffusion limited when it is high. The results are compared with the phenomenological theory developed by Horino et al. and it is shown that such a dependence of the limiting processes on the energy depositon density is induced when the diffusion is thermally activated while the reaction at the interface is ...
Anti-reflective coatings made with Teflon AF2400 had the highest damage thresholds recorded for physical vapor deposited coatings at the Lawrence Livermore National Laboratory damage facility. Physical vapor deposited layers of Teflon AF2400, a perfluorinated amorphous polymer, maintained the bulk optical properties of a high transmittance from 200 nm to 1600 nm, and a low refractive index. In addition, the refractive index can be intentionally reduced by control of two common deposition parameters, deposition rate and substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes. The coatings adhered to fused silica and silicon wafers under normal laboratory handling conditions.
A model is described for simulating thermal hydraulic and chemical conditions within fuel crud deposits. Heat transfer takes place by wick boiling in which water flows through the porous deposit and evaporates into steam at the surface of chimneys. The transport and chemistry of dissolved species within the deposit is also modelled. This chemistry includes the equilibrium chemistry of Li/boric acid species, the equilibrium chemistry of Fe/Ni species and the radiolysis chemistry of water. The unique feature of this model is that the chemistry is coupled to the thermal hydraulics via the increase in the saturation temperature with the concentration of dissolved species. This has a profound effect on evaporative heat transfer within thick deposits, leading to conditions that explain the precipitation of LiBO{sub 2} and the possible formation of bonaccordite. The model helps understand several crud scrape ...
The reaction of uranium oxides and chlorine to prepare anhydrous uranium tetrachloride (UCl{sub 4}) are important to more economical preparation of uranium metal. The most practical reactions require carbon or carbon monoxide (CO) to give CO or carbon dioxide (CO{sub 2}) as waste gases. The chemistry of U-O-Cl compounds is very complex with valances of 3, 4, 5, and 6 and with stable oxychlorides. Literature was reviewed to collect thermochemical data, phase equilibrium information, and results of experimental studies. Calculations using thermodynamic data can identify the probable reactions, but the results are uncertain. All the U-O-Cl compounds have large free energies of formation and the calculations give uncertain small differences of large numbers. The phase diagram for UCl{sub 4}-UO{sub 2} shows a reaction to form uranium oxychloride (UOCl{sub 2}) that has a good solubility in molten UCl{sub 4}. ...
The liquefaction reaction system of an NEDOL process coal liquefaction 1t/d PSU was opened and checked to investigate the cause of the rise of differential pressure between liquefaction reactors of the PSU. The liquefaction test at a coal concentration of 50 wt% using Tanito Harum coal was conducted, and it was found that the differential pressure between reactors was on the increase. By the two-phase flow pressure loss method, deposition thickness of deposit in pipelines was estimated at 4.4mm at the time of end operation, which agreed with a measuring value obtained from a {gamma} ray. The rise of differential pressure was caused by deposit formation in pipelines connecting reactors. The main component of the deposit is calcite (CaCO3 60-70%) and is the same as the usual one. It is also the same type as the deposit on the reactor wall. Ca in coal ash is concerned with this. To ...
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO_2 substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio I(111)/I(200) reaches its maximum value indicating a strong left-angle 111 right-angle texture, while the impurity concentration and resisitivity are minimum. The correlation ...
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. ...
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. ...
The Forsmark area consists of a number of natural wetlands. As a part of the evaluation of wetlands in the safety assessment for the area, possible future wetlands are being studied with respect to hydrology and transport mechanisms. A sensitivity analyses is performed to point out the governing parameters for the wetland hydraulics. The analysis of future wetlands is carried out using the hydrological model system Mike SHE. Mike SHE has been used to describe the near-surface hydrology for a regional model area in Forsmark. Three types of areas have been chosen. Today's lake Bolundfjaerden is because of its shallow depth likely to develop into a mire in the future. As it is situated in the downstream part of the regional model area, the runoff to the lake from upstream surface water system is significant. Lake Eckarfjaerden is situated in the upstream part of the catchment at a higher altitude and with a smaller ...
Cathodic arc deposition is an established and industrially applied technique for the formation of nitrides (e.g. TiN); it can also be used for metal oxide thin film formation. A cathodic arc plasma source with the desired cathode material is operated in an oxygen atmosphere of appropriate pressure, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on accelerator components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. ...
The dry deposition of pollutants can be calculated from the concentration of pollutants in the atmosphere and deposition velocity. To calculate deposition velocity, turbulence parameters such as friction velocity and Monin-Obukhov length are used. However, due to the difficulties in observation of turbulence parameters, usually mean values of wind speed and temperature observed using conventional meteorological instruments are used to estimate the dry deposition. The dry deposition velocity is the function of aerodynamic resistance (R{sub a}), sublayer resistance (R{sub b}), surface resistance (R{sub c}). R{sub a} and R{sub b} are calculated from turbulence parameters and R{sub c} is related to surface characteristics. The purpose of the present study is to compare the dry deposition obtained using the data sets of mean values and turbulence parameters measured ...
Sputter-deposited tantalum (Ta) and reactively sputter-deposited Ta-nitride films were studied with respect to the passivation capability against copper (Cu) oxidation in thermal O{sub 2} ambient. A 200 {angstrom} Ta or Ta-nitride film was sputter-deposited on a 2,000 {angstrom} Cu film using a Ta target in an Ar/N{sub 2} gas mixture. With Ta passivation, Cu was not oxidized at temperatures up to 400 C, which can be further improved by using passivation of an amorphous Ta-nitride film deposited in an appropriate condition. The absence of long-range defects in the Ta-nitride film was presumably responsible for this improvement. However, sputtering-induced surface damage by excess N{sub 2} in the sputter gas mixture may reduce the passivation capability of Ta-nitride films. When the passivated Cu was oxidized, the Cu oxides always resided in the top surface region. That is, in the oxidation process, Cu ...
A "hemispheres-in-cell" geometry is provided for prediction of colloid retention during transport in porous media. This new geometry preserves the utilities provided in the Happel sphere-in-cell geometry; namely, the ability to predict deposition for a range of porosities, and representation of the influence of neighboring collectors on the fluid flow field. The new geometry, which includes grain to grain contact, is justified by the eventual goal of predicting colloid deposition in the presence of energy barriers, which has been shown in previous literature to involve deposition within grain to grain contacts for colloid:collector ratios greater than approximately 0.005. In order to serve as a platform for predicting deposition in the presence of energy barriers, the model must be shown capable of quantitatively predicting deposition in the absence of energy barriers, which is a ...
The properties of polycrystalline (Ti, Al)N coatings deposited on non-nitrided, classically plasma-nitrided and low pressure plasma-nitrided AISI H11 steel samples were investigated. The plasma deposition and low pressure plasma nitriding were performed in a Z700-LH magnetron sputter ion plating unit, while a separate unit was used for plasma nitriding of specimens at a pressure of several millibars. The (Ti, Al)N coating was deposited onto all the samples using the same equipment as for the plasma deposition and low pressure plasma nitriding. For the characterization of the composite structures, the following methods were used: scratch test, X-ray diffraction analysis, scanning electron microscopy, scanning tunnelling microscopy and microhardness testing. It was found that plasma nitriding prior to coating deposition strongly affects the growth and properties of hard coatings, such ...
A thin film microoxidation test utilizing the concept of the Lubricant Stability Map has been used to study the effect of temperature on deposit formation by lubricants on upper piston locations of low heat rejection engines. The stability maps were established for two formulated lubricants in this study. These two lubricants were also evaluated in a series of engine tests with various piston temperatures. The deposition phenomena observed in the engine tests have been adequately simulated and described by the stability maps. It is concluded that lubricants at upper piston locations are under a thin film condition similar to that achieved by the thin film microoxidation test. The deposit formation trend is determined by the volatility, thermal stability, and oxidative stability of the base stock. Additives have little effect on deposit formation at very high temperatures. A combined consideration of all ...
The localized Pt deposition on Si by 30 keV Ga"+ focused ion beam (FIB), 10 keV electron beam (EB) or dual beams (FIB and EB) using precursor gas has been compared by analysis using a 300 keV Be"2"+ microprobe with a beam spot size of 80 nm. The distribution of deposited Pt, Ga from the ion beam itself, and C from the precursor gas was obtained at and nearby the deposited areas by micro-RBS spectra and RBS mapping. All of the beam processed areas showed a uniform Pt distribution at the deposited areas. The amount of Pt atoms increased with the increase in ion or electron dose due to the decomposition of precursor gas. The thickness of Pt layer by EB is considerably less than that by FIB due to the reduced deposition rate. Ga atoms from the center of processed areas partly redeposited at and nearby the FIB processed areas within #approx#3 #mu#m. The Ga incorporation by dual beam ...
The uptake of "2"3"8U and "2"3"2Th in different parts of some selected plants used in traditional treatment of hypertension and diabetes in south-eastern Morocco (Errachidia area) has been studied using two different types of solid state nuclear track detectors (SSNTDs) LR-115 type II and CR-39. Plant uptake of radionuclides is one of many vectors for introduction of contaminants into the human food chain. Thus, it is critical to understand soil-plant relationships that control nuclide bioavailability. Soil concentrations of uranium ranged from 6.10 to 11.62 ppm, with a mean of 7.90 ppm. Soil concentrations of thorium ranged from 2.70 to 4.80 ppm, with a mean of 3.41 ppm. Mean uranium specific activities were 8.38 Bq kg"-"1 in root tissue, 5 Bq kg"-"1 in stem tissue and 6.02 Bq kg"-"1 in leaf tissue. Mean thorium specific activities were 2.53 Bq kg"-"1 in root tissue, 1.64 Bq kg"-"1 in stem tissue and 1.96 Bq kg"-"1 in leaf tissue. The transfer ...
In the case where uranium recovered by an advanced aqueous reprocessing is utilized in light water reactors (LWRs) with the thermal neutron spectrum, the effects of the decontamination factor (DF) of the reprocessing on core neutronic characteristics were examined. The amounts of transuranium (TRU) elements and fission products (FPs) contained in the recovered uranium depend on the DF of reprocessing, and also "2"3"6U is generated by neutron capture of "2"3"5U during a reactor operation. These all act as poisons in the fuel. Therefore, in this paper, the additional "2"3"5U enrichment necessary to compensate for the produced TRU elements, FPs, and "2"3"6U was evaluated for three representative DF values: 10"2, 10"3, and infinity. The low value of 10"2 corresponds to the advanced aqueous reprocessing investigated here. An APWR core with a discharge burnup of 49 GWd/t when the initial "2"3"5U enrichment is 4.6% was considered as the reference ...
Residual radioactive material guidelines for uranium in soil were derived for the Colonie site located in Colonie, New York. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the U.S. Department of Energy (DOE). The site became contaminated with radioactive material as a result of operations conducted by National Lead (NL) Industries from 1958 to 1984; these activities included brass foundry operations, electroplating of metal products, machining of various components using depleted uranium, and limited work with small amounts of enriched uranium and thorium. The Colonie site comprises the former NL Industries property, now designated the Colonie Interim Storage Site (CISS), and 56 vicinity properties contaminated by fallout from airborne emissions; 53 of the vicinity properties were previously remediated between 1984 and 1988. In 1984, DOE accepted ...
The environmental impacts of uranium mining and milling activities are of great concern in many countries for the last three decades. These impacts range from the creation of massive stockpiles of radioactive and toxic waste rock and sand-like tailings to serious contamination of surface and groundwater with radioactive and toxic pollutants, and releases of conventional, toxic and radioactive air pollutants. Uranium mining is also associated with high concentrations of highly toxic heavy metals, which are a major source of surface and groundwater contamination. Depending upon the hydraulic properties of the fractures involved, contaminated ground water may be transported many miles from its point of origin before feeding into an aquifer. Tailings pond may contaminate the groundwater regime by continuous seepage and leaching of radionuclides and other toxic metals due to interaction of rain water through the tailings ponds. The ...
Axial offset anomaly (AOA) is caused by the deposition of crud on the fuel cladding of a PWR. When significant levels of crud build up on the cladding, boron can accumulate in the pores of the crud as a concentrated solution or solid phase, and cause the flux depression. Numerous studies have been conducted on the primary water chemistry to reduce the amount of crud in the primary circuit to avoid radioactivity buildup and unexpected power transition in the plant. However, experiments on the crud are restricted in the laboratory because the crud is a highly radioactive material. The objective of this study is to develop a test method for simulating the deposition of crud in a nuclear power plant
High power and particle deposition on target materials are encountered in many applications including magnetic and inertial fusion devices, nuclear and high energy physics applications, and laser and discharge produced plasma devices. Surface and structural damage to plasma-facing components due to the frequent loss of plasma confinement remains a serious problem for the Tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination.
Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.
Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.
The Rosebel gold district is hosted in a Paleoproterozoic greenstone belt of the Guiana Shield and has many characteristics that enable classification of the ores as an orogenic gold deposit. Host rocks have undergone several phases of deformation. However, gold deposition occurred late in the structural history of the belt, and is considered part of a late regional metallogenic event with respect to the geotectonic evolution of the Guiana Shield. Economic gold mineralization is hosted in felsic to mafic volcanic rocks and two sedimentary successions that are differentiated into turbiditic and arenitic depositional packages. The detailed lithostratigraphic characterization and the geochemistry enable the correlation of the local rock types with the Paramaka, the Armina, and the Rosebel for...
The addition of carbon to samples, during imaging, presents a barrier to accurate TEM analysis, the controlled deposition of hydrocarbons by a focused electron beam can be a useful technique for local nanometer-scale sculpting of material. Here we use hydrocarbon deposition to form nanopores from larger focused ion beam (FIB) holes in silicon nitride membranes. Using this method, we close 100-200nm diameter holes to diameters of 10nm and below, with deposition rates of 0.6nm per minute. I-V characteristics of electrolytic flow through these nanopores agree quantitatively with a one dimensional model at all examined salt concentrations.
In this study, liquid flame spray (LFS) was used to produce titania, silver and silver-titania deposits of nanoparticles. Titanium(IV)ethoxide (TEOT) and silver nitrate in ethanol solutions were used as precursors and sprayed into turbulent hydrogen-oxygen flame. Production rates of 1.5-40 mg/min of titania were used with silver additions of 1, 2, 4, and 8 wt% compared to titania. Nanoparticle deposits were collected by thermophoretic sampling at six different axial distances from the flame torch head: 3, 5, 10, 12, 15, and 20 cm, of which the all but the last one occurred inside the flame. The deposit samples were analysed by TEM and SAED analysis. The powder samples of the particles were also collected by electric precipitator to XPS and specific surface area analysis. Particle size and effective density after the flame in the aerosol were analysed with SMPS and ELPI. The results from the previous studies i.e. controlling ...
There is increasing demand to functionalize meso- and nano-porous materials by coating and make the porous substrate biocompatible or environment friendly. However, coating on a meso-porous substrate poses great challenges, especially if the pore aspect ratio is high. In the current work the pulsed laser deposition (PLD) method is used for coating Ni{sub 3}Al-based meso-porous membranes with diamond-like carbon (DLC) layers of high thickness homogeneity and adhesion. (orig.)
The workshop topics consist of FERS, FEGLI, FEHBP, Disability, Deposit/Redeposit ; TSP, Annual/Sick Leave, Annuity Calculation, Best Date to Retire, COLA's, ...
The goal of this research program is to determine whether pulsed laser deposition is an effective alternative method for growing TiCN thin films. Pulsed laser deposition (PLD) is chosen because of its well-documented capability for growing uniform, stoichiometric films in ultra-high vacuum or gaseous environments. Processing of thin films by PLD is also achieved at relatively low temperatures compared with CVD processing. Given these attributes, the primary objectives in this article are to determine whether nitrogen may be readily incorporated into films resulting from the laser-ablation of TiC in an N{sub 2} environment, determine what effect nitrogen has on mechanical properties, and determine whether nitrogen incorporation is strongly influenced by processes unrelated to laser deposition (e.g., thermally-activated surface reactions).
Oil shales of the US represent a tremendous store of potential oil. Most of the deposits are relatively unknown and warrant additional investigation. The summary presented cannot hope to cover all of the deposits. Information about them is usually available only locally. However, the 3 best known deposits - the Green River formation, the Devonian black shales, and the retort member of the Phosphoria formation - represent well over 2 trillion bbl (300 x 10/sup 12/ ton) of potential oil in place. This is an oil resource large enough to supplement quite adequately the US petroleum supply, to extend the time available for realigning our energy supply mixes, and to help reach a satisfactory solution to our current energy dilemma. The concentrated resource in the Green River formation is obviously the next most feasible source of oil. If it cannot be developed, all the other deposits will have to wait until ...
Obesity is characterized by the abnormal or excessive deposition of fat in the adipose tissue. Its consequences go far beyond adverse metabolic effects on health, causing an increase in oxidative stress,...Full Text Available
... ge aircraft engines (geae) has taken to development an induction plasma deposition (ipd) processing method for the fabrication of ti6242/sic mmc ...
The distribution of Lipiodol in the liver and lungs following arterial or portal injection was studied in normal (n=55) and cirrhotic rats (n=20). Using magnified xeroradiography and radioisotope labeled tracers, it was found that Lipiodol was deposited mainly in the liver and lung after either arterial or portal administration. In control rats after arterial injection, deposits in the lung peaked after 2 hours and gradually declined over 48 hours; whereas after portal injection, the deposit steadily increased for 48 hours. Twenty-five percent of cirrhotic rats demonstrated a Lipiodol-induced miliary pattern in the lung. An increased number of portosystemic shunts in cirrhotic rats was also noted. These results suggest that cirrhosis of the liver may be a potential risk factor for developing pulmonary complications after Lipiodol administration. (orig.).
Cold spray was employed as a novel low temperature approach to deposit titanium dioxide (TiO{sub 2}) photocatalytic film. The film microstructure was characterized using X-ray diffraction and scanning electron microscopy. The photocatalytic performance was examined through acetaldehyde degradation under ultraviolet illumination. Results showed that TiO{sub 2} film was successfully deposited on substrate surface through cold spray. The film thickness reached up to 15 {mu}m. The film presented a rough surface and porous structure. Owing to the low temperature of spray powder, no phase and particle size changes occurred to TiO{sub 2} during deposition. It was found that the cold-sprayed TiO{sub 2} film was active for photodegradation of acetaldehyde.
Focused Ion Beam (FIB) repairs and modifications to integrated circuits have been somewhat limited in the past due to the physical limitations imposed by the nodes of interest being buried under metal layers, the need for multiple layers of FIB generated interconnects, and the like. With the advent of FIB deposited INSULATOR materials, integrated circuit modifications can now be much more complex. The two primary goals of this project were (1) to determine the appropriateness of FIB insulator deposition for aiding FIB connections to metal nodes buried under power busses, and (2) development of a technique to do this. The work presented in this paper includes the development and characterization phases of adding INSULATION DEPOSITION to a FEI 611 FIB system, the problems encountered, their work around, and the aforementioned application of this technology.
A procedure based on electrophoretic deposition (EPD) was developed to coat metal plates with powder catalysts. The method was tested on stainless-steel plates with three Ni-based catalysts for the steam reforming of ethanol. The catalysts (Ni/La2O3/g-Al2O3) contained 15% Ni and 8% La, and were prepared using three types of g-alumina with different textural properties. The powder catalysts were suspended in isopropanol, and EPD deposition was performed with a voltage of 100V and a distance between electrodes of 2cm. Deposition time was varied between 3 and 7min, which gave a thickness of the catalyst layer from around 30 to 100mm. The morphology of the catalyst layer was dependent on the textural characteristics of the g-Al2O3 used to prepare the catalyst. The activity of the catalyst plat...
Indium sulfide thin films were deposited onto indium-tin-oxide coated glass substrate by electrochemical deposition from an aqueous solution containing In2 (SO4) 3 and Na2S2O3. The deposition conditions were optimized on the basis of data obtained by scanning electron microscope, Auger electron spectroscopy and optical transmission measurements. Furthermore, the photosensitivity of the films was observed by means of photoelectrochemical measurements, which confirmed that the indium sulfide showed n-type conduction. The X-ray diffraction and Raman studies revealed that the as-grown films were amorphous or nanocrystalline in nature and became polycrystalline In2S3 after annealing.
Corrosion behavior of deposition coated specimens prepared by the technique proposed by the authors is investigated in salt immersion tests, and also those of pure magnesium, 3N, 4N and 6N grades, and magnesium alloys, AZ31 and AZ91E, are investigated for comparison. Inhomogeneous corrosion occurs in AZ31 and AZ91E alloys when buffered solutions with pH values of 6.5 and 9.0 including 1% NaCl and a conventional 3% NaCl solution are used for immersion tests, while 6N-Mg shows homogeneous corrosion in such solutions. Corrosion behavior of the deposition coated specimen resembles that of 6N-Mg. Purification process included in the deposition coating technique provides homogeneity in microstructural and electrochemical terms, which results in improving corrosion resistance. (orig.)
The corrosion behavior of the sputter-deposited amorphous or nanocrystalline W-Nb alloys is studied in 10% NaCl, 0.1 and 1 M NaOH solutions at 24 deg. C, open to air using immersion tests and electrochemical measurements. Niobium metal acts synergistically with tungsten in enhancing the corrosion resistance of the W-Nb alloys so as to show lower corrosion rates than the corrosion rates of the alloy-constituting elements in almost all examined solutions. Corrosion rates of W-Nb alloys are about more than one order of magnitude less than that of the sputter-deposited tungsten and even lower than that of sputter-deposited niobium. The stability of the anodic passive films formed on the W-Nb alloys increase with niobium content.
Dosimetry parameters such as deposition, clearance, retention, and translocation and dissolution of inhaled particles in and to different lung compartments may be important for the persistence of particles...Full Text Available
The density of corn pollen on leaves of milkweed plants inside and outside of cornfields was measured in several studies from different localities. The purpose was to obtain a representative picture...Full Text Available
This paper reports on a series of experiments performed to examine the ability of ion beam assisted thermal deposition to produce good adhesion of Au metallization on GaAs left-angle 100 right-angle substrates. A study of the influence of Ar ion-assisted thermal deposition of the Au films as well as in situ pre-sputtering of the GaAs surface with low-energy Ar ions prior to thermal deposition, shows that strong adhesion can be achieved without resorting to chemical cleaning. The substrate temperature and the relative flux of Ar ions to incident Au atoms were varied in order to correlate these parameters with film adhesion. The interfaces of films processed under these various conditions were examined by XTEM, RBS and XPS. Orientation texture was studied by x-ray diffraction (XRD).
The method is related to hydrodynamic methods for studying wells and may be used in the prospecting and mapping of gas and gas condensate deposits and formations. The method consits of drilling exploratory wells and measurement of the physical parameters of the stratum liquid. The piezometric levels are periodically determined simultaneously in all the observation wells during a change in the atmospheric pressure, and the presence of a remoteness of the gas deposit from the well is judged from the size of the increments in the piezometric levels intime. The determinations of the piezometric levels in the wells are conducted during an abrupt change in atmospheric pressure, for instance, during the replacement of a cyclone by an anticyclone or the reverse. The atmospheric pressure is measured by a barograph, while the piezometric levels are measured by high precision level meters or pressure gauges of low pressure. The method increases the ...
Effects of ions of Group IA, IIA, IIIB, and VIIB elements on the cathodic deposition of a molybdenum were investigated in a KCl-LiCl (eutectic)-MoCl/sub 3/ molten salt at 773 K (500/degree/C). The results can be summarized as follows: The addition of potassium, rubidium, cesium, and barium cations and fluorine anions to the KCl-LiCl (eutectic)-MoCl/sub 3/ molten salt is effective in depressing the cathodic deposition of the molybdenum subchloride, which hinders the smooth, flat electrodeposition of molybdenum. The addition of lithium, sodium, magnesium, calcium, strontium, and aluminum cations and bromine and iodine anions promotes the undesirable cathodic deposition of the molybdenum subchloride.
Bis(imido) uranium(VI) trans- and cis-dichalcogenate complexes with the general formula U(NtBu)2(EAr)2(OPPh3)2 (EAr = O-2-tBuC6H4, SPh, SePh, TePh) and U(NtBu)2(EAr)2(R2bpy) (EAr = SPh, SePh, TePh) (R2bpy = 4,4'-disubstituted-2,2'-bipyridyl, R = Me, tBu) have been prepared. This family of complexes includes the first reported monodentate selenolate and tellurolate complexes of uranium(VI). Density functional theory calculations show that covalent interactions in the U-E bond increase in the trans-dichalcogenate series U(NtBu)2(EAr)2(OPPh3)2 as the size of the chalcogenate donor increases and that both 5f and 6d orbital participation is important in the M-E bonds of U-S, U-Se, and U-Te complexes.
Biosorption has been developed as an effective and economic method to treat wastewater containing low concentrations of metal pollutants. In this study, a bacterium, Citrobacter freudii, was used as a biosorbent to adsorb uranium ions. The thermodynamics and kinetics of this adsorption, as well as its mechanism, were investigated. The results indicated that the biosorption rate could be better described by a pseudo 2nd-order model than a pseudo 1st-order model. The adsorption of U (VI) proceeded very rapidly in the first 30 min and subsequently slowed down continuously for a long period. The biosorption isotherm of uranium by C. freudii could be described well by the Langmuir or Freundlich isotherm, and the latter was better. The thermodynamics parameters, {delta}H{sup o}, {delta}G{sup o}, and {delta}S{sup o} were calculated according to the results of the experiment, which showed this biosorption as being endothermic and spontaneous. The ...
TRACI, a model based on the physical mechanisms governing the radon transport in unsaturated soils, has been developed to evaluate the radon flux density at Uranium Mill Tailings (UMT) covers surface. First, moisture contents in the soil, induced by weather conditions, are calculated. Then, radon concentrations in the air-filled pore space, and radon flux density at the soil surface, are deduced from a transport model which takes account for diffusion and convection in the pore space. To check the hypothesis used in TRACI and the efficiency of cover layers, an in situ study was launched in 1997 with the French uranium mining company, COGEMA. It consists of continuous measurements of moisture contents, suctions, radon concentrations at various depths inside an UMT cover, and flux density at its surface. The first analysis made on in situ observations shows that radon concentrations and flux density, calculated with a steady-state diffusion model ...
As part of the national survey to evaluate natural radioactivity in the environment, concentration levels of natural uranium and "2"2"6Ra have been analyzed in over 300 drinking water samples taken from different locations in Argentina. "2"2"6Ra was determined by "2"2"2Rn emanation and liquid scintillation counting, and natural uranium by a fluorimetric procedure. Values ranging from 0.03 to 24 #mu#g.l"-"1 of natural uranium and from 0.06 to 50 #mu#g.l"-"1, were measured on drinking water samples taken from tap water systems and private wells, respectively. Concentrations up to 15 mBq.l"-"1 and to 22 mBq.l"-"1 of "2"2"6Ra were found in drinking water samples taken from tap water systems and private wells, respectively. These values are compared with the reference values accepted for drinking water. Based on the water intake rate, the age distribution and the measured concentrations, an annual collective effective dose of ...
Rehabilitation of the abandoned uranium mining areas in Saxonia and Thuringia is a task posing also legal problems. The radiation protection laws of the former GDR continued to be effective to a great extent and proved to be a legal basis not ``perfect`` in formal terms, but suitably efficient in practice to tackle the manifold problems encountered in the land reclamation and waste disposal work. Originally intended to serve as a legal interim regime awaiting amendment at a later date, the body of laws available for the task proved to be a sufficient basis. (orig./HP) [Deutsch] Das fortgeltende Strahlenschutzrecht der frueheren DDR hat sich zwar nicht als formal `perfektes`, in der Sache aber strahlenschutzgerechtes und praktikables Instrument zur Loesung der anstehenden Sanierungsaufgaben erwiesen. Bei seiner Beurteilung darf nicht ausser Acht gelassen werden, dass die Ueberleitung dieses Rechts seinerzeit aus der Not eines kurzfristigen Regelungsbedearfs geboren ...
In order to effectively recover uranium, rotation speed of solid cathode was examined, and effect of uranium concentration and current density on electrodeposition were confirmed. And the potentiostatic and galvanostatic electrorefining experiments were conducted. Element used in the experiments were Zr, Nd, La chlorides. The reduction potentials of chlorides metals on liquid Cd cathode were measured by cyclic voltammetry experiments. The electrowinning experiments were performed in order to recover small amounts of uranium in salt. Experimental set-up for the batch type reductive extraction experiments were developed and installed. On the base of experimental results of batch type, multi-stage extraction equipment was set-up, and optimum number of stage and recover yield were measured. In the oxidative extraction study is examine selective separation behavior of the rare earth metals from alloy composed of actinide and ...
To carry out studies on the radon behavior under controlled and stable conditions it was designed and constructed a system that consists of two parts: a container of mineral rich in Uranium and an experimentation chamber with radon united one to the other one by a step valve. The container of uranium mineral approximately contains 800 gr of uranium with a law of 0.28%; the radon gas emanated by the mineral is contained tightly by the container. When the valve opens up the radon gas it spreads to the radon experimental chamber; this contains 3 accesses that allow to install different types of detectors. The versatility of the system is exemplified with two experiments: 1. With the radon experimental chamber and an associated spectroscopic system, the radon and two of its decay products are identified. 2. The design of the system allows to couple the mineral container to other experimental geometries to demonstrate this fact ...
A new method for the determination of {sup 237}Np and Pu isotopes in large soil samples has been developed that provides enhanced uranium removal to facilitate assay by inductively coupled plasma mass spectrometry (ICP-MS). This method allows rapid preconcentration and separation of plutonium and neptunium in large soil samples for the measurement of {sup 237}Np and Pu isotopes by ICP-MS. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via {sup 238}U peak tailing. The method provides enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then transferring Pu to DGA resin for additional purification. The decontamination factor for removal of uranium from plutonium for this method is greater than 1 x 10{sup 6}. Alpha spectrometry can also be applied so that the shorter-lived {sup 238}Pu isotope can be measured successfully. {sup 239}Pu, ...
The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca precipitation and ...
One option in establishing advanced technology for disposing of high-level radioactive waste (HLW) is to remove TRU elements from HLW and then transform them into short-lived radionuclides. Tertiary pyridine-type anion exchange resin was investigated as a separation medium for spent fuel reprocessing using a HCl solution. Distribution coefficients of typical elements, along with uranium, were measured in the pyridine resin--HCl solution system, where HCl concentration was varied from 1 to 9 M. The results reveal: elements of the alkali metal, alkaline earth and lanthanide groups are not adsorbed, the adsorption patterns of the transition metals differ according to HCl concentration, and uranium is adsorbed in the high HCl concentration region. Furthermore, the present report describes the experimental results obtained for the adsorption behaviour of uranium, americium, curium and various lanthanide elements on tertiary ...
This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost ...
A biogenic method for the treatment of uranium mill effluents containing toxic amounts of Mn"2 and "2"2"6Ra is described. The acidic tailings from the uranium mills are generally neutralised with lime and the overflow waters from tailing ponds at the discharge point, consisting of Mn"2"+ (>10 mg l"-"1) and "2"2"6Ra (> 3.0 pCi l"-"1), need further treatment before disposing off to the public utility. Arthrobacter sp. has been used for precipitating Mn"2"+ as hydrous oxide of manganes (MnO_2#centre dot#nH_2O) and along with "2"2"6Ra also gets precipitated. The effluent after bacterial treatment consisted of Mn"2"+ and "2"2"6Ra within the range of allowed concentrations as per the I.C.R.P. (International Committee of Radiological Protection) and MPC (maximum permissible concentration) standards (Mn"2"+ 95% of "2"2"6Ra could be precipitated using this method. (author). 11 refs.; 4 figs.; 4 tabs.
The /sup 252/Cf-source-driven neutron noise analysis method for obtaining the subcriticality of an assembly of fissile material from cross-power spectral densities (CPSDs) was developed to avoid some difficulties inherent in other measurement methods. This method requires measurement of frequency-dependent CPSD between a pair of detectors in or near the fissile assembly and CPSDs between these detectors and a source of correlated neutron noise from an ionization chamber containing /sup 252/Cf, also in or near the fissile assembly. Also, the auto-power spectral density of the source is required. The ratio of spectral densities is then formed and is related to the subcriticality. To date various measurements have been performed which demonstrate the usefulness of the method including measurements with single uranium metal cylinders. The experiments described here, which used coupled uranium (93.15 wt % /sup 235/U) metal cylinders separated by ...
This paper explores the potential of combining substance-flow modelling with water and wastewater sampling to trace consumption-related substances emitted through the urban wastewater. The method is exemplified on sucralose. Sucralose is a chemical sweetener that is 600 times sweeter than sucrose and has been on the European market since 2004. As a food additive, sucralose has recently increased in usage in a number of foods, such as soft drinks, dairy products, candy and several dietary products. In a field campaign, sucralose concentrations were measured in the inflow and outflow of the local wastewater treatment plant in Linkoping, Sweden, as well as upstream and downstream of the receiving stream and in Lake Roxen. This allows the loads emitted from the city to be estimated. A method c...
The potential of different multitemporal and multispectral airborne and spaceborne remote sensing methods for assessment and monitoring of the lignite open-cast mining areas are discussed in this chapter. Emphasis is placed on the successful use of different remote sensing data in variable vegetation structures for dumped sediments with different mineralogical and geochemical properties and for hydrochemical properties of the residual lakes. Multiple remote sensing data are a cost and time efficient tool for the assessment of environmental impacts, supervising of reclamation activities as well as for long term monitoring of the mining area. The airborne data are well suited for large scale detailed research and mapping in smaller sites and the satellite data for the overview scale 1:50 000. An integrated remote sensing-GIS-system including all field and lab data, DTM and other graphical data, improve the results of the remote sensing data classification for the ...
The general objective of this workshop is to investigate and discuss methods by which uncertainties in mass balance models for toxics in the Great Lakes may be reduced. As described by the workshop prospectus, this paper is focused on problems of reducing (and quantifying) uncertainty as they relate to in situ field observations/system response measurements for the establishment of initial conditions, boundary conditions, calibration/confirmation data sets, and model post-audit data sets.'' I have taken this description to refer not only to the evaluation of uncertainty in the field observations themselves, but also to the uncertainty associated the analyses of in situ observations as they interact in the overall modeling process. Thus, I will be concerned here with quantification and reduction of uncertainty both (1) as they may be applied to descriptions of the system that is being modeled and (2) as they may be associated with model ...
This paper presents a dynamic displacement influence line method for moving load identification on bridge. The finite element model of Poyang Lake continuous truss bridge-train systems is established and the dispersed modal shapes are acquired by modal analysis. Multi-axle moving train loads are identified with simulated annealing genetic algorithm by minimizing the errors between the measured displacements and the reconstructed displacements from the identified moving loads. In the identification process, the dynamic displacement influence line technique is used to calculate the time history displacement responses of the bridge to avoid solving equations of motion of the bridge repetitively. Several important parameters of the bridge-train system are discussed to investigate their effects...
Summary Indigenous people demonstrably lived along rivers and around lakes and wetlands of Australia's Murray-Darling Basin in pre-European times. Waterways were, and continue to be, of major significance to the society and culture of Aboriginal peoples throughout Australia. Historically, they exploited most of the fauna - from mussels and crayfish, to fish and birds - and either ate, or used for other purposes, many species of aquatic plants. Such practices placed them in the role of environmental modifiers, a role played by all human groups from both past and present. They built sophisticated fish traps, cut gaps in river banks to allow fish to move on to floodplains, and there is evidence that they practised a form of fish culture by creating small impoundments in which small fish could...
The commercialization of geothermal energy resources consists of a sequence of exploration, development, and utilization activities. Each of these activities are beset by both generic and project specific technical, environmental, and institutional constraints which must be adequately resolved before geothermal operations can be conducted. This report presents a summary of selected environmental activities conducted during the early planning stages of geothermal resource commercialization. Three representative activities are elaborated upon. These include preliminary environmental planning for geothermal energy development in the Medicine Lake Highlands of California; potential alternatives for non-electric use of the geothermal resource at East Mesa in Imperial County, California; and site specific studies of the impacts from using East Mesa geothermal fluids to irrigate selected crops and indigenous climax vegetation.
The biota of the Mississippi River in an ecological recovery zone near Red Wing, MN was studied before and after start-up of a nuclear plant to acquire baseline data and to estimate changes due to thermal addition. Thermal addition produced significant decreases in primary production in a plant region during summer month periods when water temperatures were near 36C. Extensive fisheries studies and sonar tagging/tracking of S. vitreum were performed. Comparison of fisheries results with other riverine, lake, and pond studies indicated a favorable environment for the success of the fish species studied. Qualitative macroinvertebrate surveys were conducted.
Previous studies indicate that the hatching success of brine shrimp (Artemia franciscana) cysts is surprisingly sensitive to ambient metal concentrations. These studies estimated median effective concentrations (EC50s) of 7, 5, and 28??g l?1 for Cd, Cu, and Zn, suggesting that the hatching end point for A. franciscana is the most sensitive tested to date for Cd and Zn in saline environments and comparable in sensitivity with the most sensitive tested to date for Cu. Furthermore, these data suggest that brine shrimp are at significant risk from Cu and Zn in Great Salt Lake (GSL), UT, where ambient concentrations as high as 10 and 14??g l?1, respectively, have been measured. Given that brine shrimp appear to be successfully reproducing in GSL, we hypothesized that these toxicity values were ...
Western Area Power Administration (Western) is a power marketing agency of the US Department of Energy, with jurisdiction in 15 western states. The Salt Lake City Area (SLCA) of Western performs the agency`s mission in parts of Colorado, New Mexico, Texas, Utah, Arizona, Wyoming, and Nevada. As part of its mission, Western owns, operates, and maintains a system of transmission lines for transmitting bulk electrical energy from points of generation to and between delivery points. Part of that system in southwestern Colorado includes the Blue Mesa-Curecanti and Blue Mesa-Salida 115-kV transmission lines. Western proposes to conduct maintenance and improve its access roads for these two transmission lines. This paper discusses the impacts to the existing environment as well as the environmental consequences resulting from the maintenance and construction that is proposed.
This summary report outlines the work that was performed to gain a more complete understanding of denting corrosion of steam generators in PWRs. Background laboratory and plant data on denting were compiled, reviewed and correlated to determine how various exposure conditions affect denting. Two high-temperature chemistry analytical models were reviewed and evaluated by experimental simulation of impurity concentration in the heat transfer and isothermal capsule tests. Simulation of impurity concentration for three cooling waters (lake, river, and cooling tower) was evaluated. The effects of species concentration (Cu/sup + +/, Cl/sup -/, O/sub 2/, and H/sup +/), contaminant thresholds (established by isothermal and heat transfer tests), and heat flux as indicated by superheat on denting were examined. A discussion of several pertinent observations and conclusions drawn from these tasks (as they pertain to plant operation) is presented.
The IGCC of the U.S. government was created under the intent of Public Law 93-410 (1974) to serve as a forum for the discussion of Federal plans, activities, and policies that are related to or impact on geothermal energy. Eight Federal Departments were represented on the IGCC at the time of this meeting. The main presentations in this report were on: Department of Energy Geothermal R&D Program, the Ormat binary power plant at East Mesa, CA, Potential for direct use of geothermal at Defense bases in U.S. and overseas, Department of Defense Geothermal Program at China Lake, and Status of the U.S. Geothermal Industry. The IGCC briefing books and minutes provide a historical snapshot of what development and impact issues were important at various time. (DJE 2005)
Human impacts such as eutrophication, overexploitation and climate change currently threaten future global food and drinking water supplies. Consequently, it is important that we understand how anthropogenic resource (bottom-up) and consumer (top-down) manipulations affect aquatic food web structure and production. Future climate changes are predicted to increase the inputs of terrestrial dissolved organic carbon to lakes. These carbon subsidies can either increase or decrease total basal production in aquatic food webs, depending on bacterial competition with phytoplankton for nutrients. This study examines the effects of carbon subsidies (bottom-up) on a pelagic community exposed to different levels of top-down predation. We conducted a large scale mesocosm experiment in an oligotrophic ...
This paper describes progress in several projects related to biomass power. These include switchgrass conversion development; switchgrass gasification development; production activities including soil studies, carbon studies, switchgrass production economics, watershed impacts, and prairie lands bio-products; information and education; and geographical information system. Attachments describe switchgrass co-firing test; switchgrass production in Iowa; cooperative agreements with ISU; Rathbun Lake watershed project; newspaper articles and information publications; Secretary of Agriculture Glickman`s visit; integration of technical aspects of switchgrass production in Iowa; and evaluation of an integrated biomass gasification/fuel cell power plant.
In the framework of the search for a ceramic material usable in the radioactive waste storage, uranium and thorium phosphates have been investigated. Their experimental synthesis conditions have been entirely reviewed, they lead to the preparation of four new compounds: U(UO{sub 2})(PO{sub 4}){sub 2}, U{sub 2}O(PO{sub 4}){sub 2}, UCIPO{sub 4}, 4H{sub 2}O, and Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}. Experimental evidenced are advanced for non existent compounds such as: U{sub 3}(PO{sub 4}){sub 4}, U{sub 2}O{sub 3}P{sub 2}O{sub 7} and Th{sub 3} (PO{sub 4}){sub 4}. Characterization by several techniques (X-rays and neutron powder diffractions, UV-Visible and Infra-red spectroscopies, XPS,...) were performed. The ab initio structure determination of U(UO{sub 2})(PO{sub 4}){sub 2} has been achieved by X-rays and refined by neutron diffractions. Through its physico-chemical analysis, we found that this compound was a new mixed valence uranium ...
Polymeric coated ferromagnetic carriers with an absorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted by tributyl phosphate (TBP) are being evaluated for application in the separation and the recovery of low concentrations of americium, plutonium, and uranium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles and the complexed particles can be recovered from the solution using a magnet. Physical and chemical characterization of the extractant-absorbed particles were performed by gamma and liquid scintillation counting, scanning electron microscopic (SEM) micrograph, and other physical measurements. Plutonium, americium, and uranium separations have been performed at various HNO{sub 3} and HCl concentrations. Parameters were studied to determine the limitations and capacity of the process. The status of the ...
A novel microcapsule adsorbent for separation of uranium from phosphoric acid solutions was developed by immobilizing the di(2-ethylhexyl) phosphoric acid-?trioctyl phosphine oxide extractants in the polymeric matrix of calcium alginate. Physical characterization of the microcapsules was accomplished by scanning electron microscopy and thermogravimetric techniques. Equilibrium experiments revealed that both ion exchange and solvent extraction mechanisms were involved in the adsorption of Formula Not Shown ions, but the latter prevailed in a wider range of acid concentration. According to the results of kinetics study, at low acidity level, the rate controlling step was slow chemical reaction of Formula Not Shown ions with the microdroplets of extractant, whereas it changed to intraparticle...
Ford, Bacon, Davis Utah Inc. has reevaluated the Spook site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings 48 mi northeast of Casper, in Converse County, Wyoming. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 187,000 tons of tailings at the Spook site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.
This series of measurements with a mixed Pu-U nitrate solution (280 g Pu/liter, 180 g U/liter) in a 35.54-cm-diam cylindrical tank provides a wide variety of experimental data for subcritical configurations that can be used to verify calculational methods and nuclear data. The Pu contained 7.85 wt% {sup 240}Pu and the uranium was natural uranium. The measurements performed were: inverse count rate, prompt neutron decay constants, inverse kinetics, and frequency analysis by the {sup 252}Cf source driven method. These data are presented in sufficient detail that the results of the experiments can be calculated directly. For purposes of extrapolating to the delayed critical height the ratio of spectral densities was linear with height and thus provided the best estimate of critical height.
A new reagent 7-(6-Br-2-henzthiazolilazo)-8-oxyquinoline-5-sulphoacid has been studied spectrophotometrically. Dissociation constants have been determined in 50% acetone (pK_1=2.5 and pK_2=5.9) and 50% dioxane (pK_1=1.7 and pK_2=6.1) as well as molar extinction coefficients of the reagent dissociated form in the same solvents (71.1.10"3 and 72.4.10"3). The conditions have been studied of complexing the reagent with ions of uranium (6), zinc (2), and manganese (2) in 50% dioxane (pH 2.5-4.5) and the properties of the formed complexes.
A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity RbCl product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant RbCl is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.
A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity RbCl product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant RbCl is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.
This paper first introduces the calculating method of radium specific activity to determine the radon emanation rate of tailing of uranium mine No. 794, the method needs two parameters: radon emanation coefficient and radon diffusion coefficient. According to the measured results of parameters and the contrast between radium specific activity of indoor chemical analysis of field sample and field gamma-ray spectra, the authors discuss the variation rules and characteristics of radon emanation coefficient and radon diffusion coefficient, and the best climate and seasons for measuring these parameters in northern China, and finally summarize the characteristics of this method through analyzing measured results. (authors)
Feasibility of using fixed bed column of conventional ion exchangers/sorbent and chemical precipitation based processes have been examined for the effective removal of the very low levels of 106Ru activity from NH4NO3 effluent generated during wet processing of rejected sintered depleted uranium fuel pellets. Based on the results, a simple process involving precipitation of cobalt sulphide along with ferric hydroxide was selected and further optimization of process variables was carried out. The optimized process has been found to be highly efficient in reducing 106Ru activity down to extremely low levels.
The theory of a method of determination of the reactivity from power spectral density measurements with /sup 252/Cf and the results of experiments with a critical assembly mock-up of a liquid-metal fast breeder reactor and with uranium (93.2 wt % /sup 235/U) metal cylinders and a sphere are presented. This method of reactivity determination has an advantage over existing methods in that it determines the reactivity only from properties of the reactor at the subcritical state of interest and thus does not require a calibration near delayed criticality. In these experiments the reactivity was varied by changing the fissile loading or the amount of neutron absorber inserted; for the LMFBR mock-up, the reactivity varied to approximately 75 dollars subcritical, and for the uranium metal assemblies, to approximately 30 dollars subcritical.
Three different fuels UO{sub 2}-only, UO{sub 2}-Gd{sub 2}O{sub 3}(5%), and UO{sub 2}-Gd{sub 2}O{sub 3}(10%) were produced by sol-gel technique. Their powder characteristics such as flowability, BET surface area, average pore diameter, and cumulative pore volume were determined. The pore size distributions of powders, green pellets, and sintered fuels were determined by using a mercury porosimeter. The theoretical densities of sintered fuels were found to be 98.01, 95.3, and 95.9 %, respectively. Their ruggedness fractal dimensions were 1.111, 1.044, and 1.042, while the fractal dimensions associated with the size distribution of grains were 1.44, 1.58, and 1.60, respectively. (orig.).
LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at 13Hz providing a 500MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000MW by continuously varying the 6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in th...
We present a unified description of the imaginary part of the dynamical magnetic susceptibility #chi#"'"'(#omega#.T) and measurements of the static susceptibility #chi#(T) and electrical resistivity #rho#(T) in the uranium intermetallics UCu_5_-_xPd_x (x = 1.1.5). For temperatures T and excitation energies #omega# in the range 12 K < #omega#, T < 150 K, our analysis demonstrates that the dynamics of isolated uranium ions are responsible for the observed temperature and frequency scaling, although interion interactions may become important at lower temperatures and frequencies. We derive a strict criterion for single-ion scaling in the form of a universal scaling function, providing a model-independent description of the compiled experimental data. (orig.).
A characterization study was performed on monosodium titanate (MST) particles to determine the effect of high shear forces expected from the In-Tank Precipitation (ITP) process pumps on the particle size distribution. The particles were characterized using particle size analysis and scanning electron microscopy (SEM). No significant changes in particle size distributions were observed between as-received MST and after 2--4 hours of shearing. Both as-received and sheared MST particles contained a large percentage of porosity with pore sizes on the order of 500 to 2,000 Angstroms. Because of the large percentage of porosity, the overall surface area of the MST is dominated by the internal surfaces. The uranium and plutonium species present in the waste solution will have access to both interior and exterior surfaces. Therefore, uranium and plutonium loading should not be a strong function of MST particle size.
This report presents the results of an experimental programme to determine the mass transfer and sorptive properties of selected glacial sand and clays from the Drigg Disposal Site operated by British Nuclear Fuels plc. The hydraulic conductivity of both the sand and clay has been determined and the sensitivity of this parameter to changing water chemistry investigated. The hydrodynamic dispersion properties of the glacial sand were measured in order to aid the interpretation of column sorption experiments. The sorption of strontium and uranium from groundwater onto clay and sand samples has been studied using through-diffusion, column and batch techniques. Employing the batch technique, the effect of a series of humic acid concentrations on distribution ratios for uranium and plutonium has also been investigated. Groundwater and trench leachate were used with both clay and sand. (author).
A set of 35 uranium ore and 10 yellow cake samples, collected worldwide from different mines and production sites, were analyzed for their impurity spectrum by ICP-MS. Pattern recognition techniques such as cluster analysis were applied to the data set in order to characterize samples with relation to their geographical origin. The results obtained show a clear relationship between samples taken from the same geological origin and constitute a satisfactory fingerprint for establishing the origin of the material. In addition to the impurity data, data on the isotopic composition of radiogenic lead is used to resolve ambiguity when impurity cluster analysis fails to deliver unambiguous origin data. (author)
The hyperfine interactions at the uranium site in the antiferromagnetic USb2 compound were calculated within the density functional theory (DFT) employing the augmented plane wave plus local orbital (APW+lo) method. We investigated the dependence of the nuclear quadruple interactions to the magnetic structure in USb2 compound. The investigation were performed applying the so called band correlated LDA+U theory self consistently. The self consistent LDA+U calculations were gradually added to the performed generalized gradient approximation (GGA) including scalar relativistic spin orbit interactions in a second variation scheme. The result, which is in agreement with experiment, shows that the 5f-electrons have the tendency to be hybridized with the conduction electrons in the ferromagnetic uranium planes.
Being based on the Segal method, calculation was carried out for the natural uranium nuclear fuel cost with Zircaloy-4 cladding having design parameters of Wolsung Nuclear Power Plant, CANDU-PHWR (Unit 1), currently under construction in Korea aiming at its completion in 1982. An attempt was also made for the sensitivity analysis of each fuel component; i.e., depreciation of fuel manufacturing plant caused by its life time, its load factor, production scale expansion of plant facilities, variations of construction and operating costs of fuel manufacturing plant, fluctuation of interest rates, extent of uranium ore price increases and effect of learning factor. (author).
The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi/m/sup 2/ s by application of covering layers of soils and clays. These covers present a radon diffusion barrier, which sufficiently increases the time required for radon passage from the tailings to the atmosphere to allow for decay of /sup 222/Rn within the cover. The depth of cover necessary to reduce the escaping radon flux to the prescribed level is to be determined by calculation, and requires precise knowledge of the radon diffusion coefficient in the covering media. A Radon Attenuation Test Facility was developed to determine rates of radon diffusion through candidate cover materials. This paper describes this facility and its application for determining the influence of physical properties of the soil column on the radon diffusion coefficient.
Ford, Bacon and Davis Utah Inc. has reevaluated the Tuba City site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Tuba City, Arizona. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 0.8 million tons of tailings at the Tuba City site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.
A Process for yellow cake production from local Euxenite was developed in Bench Scale by using sulphuric acid digestion with simultaneously ion-exchange and solvent extraction purification steps. Uranium was then precipitated as uranium diuranate by ammonia solution. Equipment used in this process includes : digestion vessels, columnar ion-exchange, solvent extraction and precipitation units Ore feed to the process could be adjusted up to 2 kilogram per day (8 hours operation) with yellow cake product purity meet the requirement of Usaec standard of about 10-50 gram per day. Included in this experiment are the leaching characteristics of the ore, the design and construction of continuous columnar 4-cycle ion exchange unit, determination of the extraction and stripping stages of a gravity flow mixer-settler and the design and construction of continuous yellow cake precipitation unit with large grain size and high density product
The objective of this project is to develop multi-dimensional computational models in order to improve the operation of uranium electrorefiners currently used in pyroprocessing technology. These 2-D (US) and 3-D (ROK) mathematical models are based on the fundamental physical and chemical properties of the electrorefiner processes. The validated models by compiled and evaluated experimental data could provide better information for developing advanced electrorefiners for uranium recovery. The research results in this period are as follows: - Successfully assessed a common computational platform for the modeling work and identify spatial characterization requirements. - Successfully developed a 3-D electro-fluid dynamic electrorefiner model. - Successfully validated and benchmarked the two multi-dimensional models with compiled experimental data sets
The paper describes novel analytical methods developed for the detection of previous neutron irradiation and reprocessing of illicit nuclear materials, which is an important characteristic of nuclear materials of unknown origin in nuclear forensics. Alpha spectrometry and inductively coupled plasma sector-field mass spectrometry (ICP-SFMS) using solution nebulization and direct, quasi-non-destructive laser ablation as sample introduction were applied for the measurement of trace-level "2"3"2U, "2"3"6U and plutonium isotopes deriving from previous neutron irradiation of uranium-containing nuclear materials. The measured radionuclides and isotope ratios give important information on the raw material used for fuel production and enable confirm the supposed provenance of illicit nuclear material.
Biosorption of uranium (VI) ions by immobilized Aspergillus fumigatus beads was investigated in a batch system. The influences of solution pH, biosorbent dose, U (VI) concentration, and contact time on U (VI) biosorption were studied. The results indicated that the adsorption capacity was strongly affected by the solution pH, the biosorbent dose and initial U (VI) concentration. Optimum biosorption was observed at pH 5.0, biosrobent dose (w/v) 2.5%, initial U (VI) concentration 60 mg L{sup -1}. Biosorption equilibrium was established in 120 min. The adsorption process conformed to the Freunlich and Temkin isothermal adsorption models. The dynamic adsorption model conformed to pseudo-second order model.
The Plutonium-Uranium Extraction (PUREX) Plant, conceived during the early Cold War years, was a vehicle to increase significantly US nuclear weapons production capacity. The original PUREX Plant was a concrete rectangle 1,005 feet long and 61.5 feet wide. The shielding capacity of the concrete was designed so that personnel in non-regulated service areas would not receive radiation in excess of 0.1 millirem per hour. This report discusses the design of the PUREX Plant, the production chronology, projects and equipment changes, equipment decontamination and reuse, waste management, and contamination events that have occurred during the operation of the plant. Additionally, the development and history of the Uranium Trioxide Plant are also covered.
This report presents the results of a study dealing with the homogeneous recycling of either Pu or Pu+Np or Pu+Np+Am or Pu+Np+Am+Cm in PWRs using MOX-UE fuel, i.e. standard MOX fuel with a U235 enriched uranium support instead of the standard tail uranium (0.25%) for standard MOX fuel. This approach allows to multirecycle Pu or TRU (Pu+MA) as long as U235 is available, by keeping the Pu or TRU content in the fuel constant and at a value ensuring a negative moderator void coefficient (i.e. the loss of the coolant brings imperatively the reactor to a subcritical state). Once this value is determined, the U235 enrichment of the MOX-UE fuel is adjusted in order to reach the target burnup (51 GWd/t in this study).
The effect of atmospheric radioactive emissions from United Kingdom nuclear installations on acid deposition is assessed. Nitrogen oxide and ozone production resulting from and associated with discharges of airborne radioactivity, comparison with conventional emissions, and the direct effects of radioactive emissions on trees, are all discussed. (UK).
An examination is made of the structure of the North Saremboyskiy oil field and productive lower Devonian deposits of well 15. Based on detailed lithological studies, as well as investigation of filtering-capacitance properties of rocks, the complex structure of the carbonate deposits and the dominant development of complex type collectors is indicated.
Magnetron sputter deposition was used to fabricate body centered cubic (bcc) and A-15 crystal structure W thin films. Previous work demonstrated that the as-deposited crystal structure of the films was dependent on the deposition parameters and that the formation of a metastable A-15 structure was favored over the thermodynamically stable bcc phase when the films contained a few atomic percent oxygen. However, the A-15 phase was shown to irreversibly transform into the bcc phase between 500 C and 650 C and that a significant decrease in the resistivity of the metallic films was measured after the transformation. The current investigation of 150 nm thick, sputter deposited A-15 and bcc tungsten thin films on silicon wafers consisted of a series of experiments in which the stress, resistivity and crystal structure of the films was measured as a function of temperatures cycles in a Flexus 2900 thin film ...
Exploration for oil shale in Queensland between June 1986 and July 1987 continued over 12 deposits ranging in age from Permian to Tertiary. The total estimated resource of shale oil contained within these deposits is 4479 GL (28.2 billion barrels). 4 refs., 1 fig., 1 tab.
Natural radioactivity of rocks is studied on the basis of core samples and radioactivity logs of marine deposits in Azerbaijan. Investigations have established mainly thorium-potassium nature of radioactivity. Data obtained are useful for identificafion of clay among other rocks, for determination of clayiness, and in presence of a corresponding relation - for determination of porosity according to the clayiness. It is shown that the clayiness may be determined from radioactive logs.
The mobilization and distribution of previously deposited "2"3"9Pu was compared in pregnant rats (15 and 20 days of gestation) and nonpregnant controls. Pregnancy had little effect on "2"3"9Pu tissue burdens and only minimal activity appeared in the fetoplacental unit. Marked differences were observed in tracer "4"5Ca deposition patterns between the experimental groups.
The formulation of the problem of classification of lithologically heterogeneous rocks and rocks with mixed capacity space is analyzed under conditions of self-teaching. Using the example of one of the boreholes of the Pripyat trough we illustrated the possibilities of the Kompakt algorithm to classify deposits of the Frasnian stage without using standard data. Problems are listed for further study on the development of methods of application of self-teaching classification systems in the petroleum industry.
In accordance with the comprehensive plan in the eleventh five-year period the main content of prospecting and exploration on land in Axerbaidzhan by the Axneft' association will be done in the central and Western regions of the republic, where Paleogene-Mesozoic deposits will be inspected. Discussed in detail are the directions and volumes of prospecting and exploration in individual regions of Azerbaidzhan. They are determined with consideration of the degree of exploration of the earth's interior, the prospects for the deposits comprising them, and the development of the resources of oil.
Approximately 700m of deep water clastic deposits of Mt. Messenger Formation are superbly exposed along the Taranaki coast of North Island, New Zealand. Biostratigraphy indicates the interval was deposited during the time span 10.5-9.2m.y. in water depths grading upward from lower bathyal to middle-upper bathyal. This interval is considered part of a 3rd order depositional sequence deposited under conditions of fluctuating relative sea-level, concomitant with high sedimentation rates. Several 4th order depositional sequences, reflecting successive sea-level falls, are recognized within the interval. Sequence boundaries display a range of erosive morphologies from metre-wide canyons to scours several hundred metres across. All components of a generic lowstand systems tract--basin floor fan, channel-levee complex and progading complex--are present in logical and temporal order. They ...
The Buntsandstein facies outcrops along a 12 km long, 150 m thick cuesta near Ayllon (Central Spain). The outcrop study is based on vertical sedimentological sections and continuous photo paneling, and demonstrates the presence of two depositional systems: an alluvial fan system in the lower half of the outcrop, and a straight and braided river system in the upper part of the outcrop. This overall evolution is probably related to base-level fall to base-level rise cycle, in which the reservoir architecture is linked to genetic units stacking pattern: during the base-level fall, the alluvial fan is prograding over sand flat and sandy alluvial plain deposits. Coarse and pebbly proximal sandsheets are interbedded with finer reddish distal deposits. Reservoirs units are laterally continuous, but silty alluvial plain deposits constitute vertical permeability barriers, during base-level stillstand, erosive ...
The glacial deposits of the West Tensleep Basin in the Bighorn Mountains of Wyoming are mapped and a relative chromology established. The deposits are correlated with the regional model as defined in the Wind River Mountains. A statistical analysis is performed on the density and weathering characteristics of the surficial boulders to determine their validity as indicators of relative age. (ACR)
Deposition of CN-based films by a novel version of active screen plasma nitriding, aiming at surface modification of polymers, is reported. The approach relies on the use of pure graphite as the grid material, which was found to act both as an active screen and as a dry source of carbon atoms for the synthesis of thin films consisting mainly of a stoichiometric CN layer with columnar-type structure and dome-like nanostructured morphology.
During last decade, considerable interest has been focused to assess the influence of human activities on ecosystems. The increasing trend in the atmospheric concentration of CO{sub 2} has been predicted to continue till the next century and the amount of nitrogen deposition in the northern hemisphere has increased markedly. Substantial interest has been focused on predicting how these changes will affect on plants. Most boreal mire ecosystems are dominated by mosses of the genus Sphagnum, the litter of which constitutes the main component in the peat deposits and is an important CO{sub 2} sink via peat formation. Since virtually nothing was known about the growth response of peat mosses to elevated concentrations of CO{sub 2} and alerting changes in species composition were detected in the sensitive ombrotrophic mire vegetation under increased N deposition in central Europe, this study was established. Laboratory ...