Abstract  Nitrogen mustard N-oxide was tried for the fixation of tissue for electron microscopy. A fixative consisting of 1% nitrogen mustard N-oxide, 1% glutaraldehyde and 1% paraformaldehyde buffered at pH 7.4 followed by 1% OsO4 buffered at pH 7.4 was found useful for the tissues examined: thyroid, anterior pituitary, adrenal gland and oviduct of mice. If the tissues are fixed and the sections are stained with uranyl acetate and lead acetate doubly, the follicle colloid, colloid droplets, and secretory granules containing thyroglobulin in the thyroid become higher in electron density. The cisterna of the maturing face of the Golgi apparatus, secretory granules, ribosomes, nucleolus and chromatin in the cells examined are extremely electron dense. Tubular elements of smooth endoplasmic reticulum in the adrenal cortical cell and microtubules in all the cells examined are also well preserved. The fixative containing nitrogen mustard N-oxide is useful also for cytochemistry. Using tissue fixed by this method and stained en bloc by uranyl acetate, the noradrenaline and adrenaline cells in the adrenal medulla are clearly distinguished by light microscopy.

Abstract  Water-resources investigations.

Abstract  Microbial communities from riparian sediments contaminated with high levels of Ni and U were examined for metal-tolerant microorganisms. Isolation of four aerobic Ni-tolerant, Gram-positive heterotrophic bacteria indicated selection pressure from Ni. These isolates were identified as Arthrobacter oxydans NR-1, Streptomyces galbus NR-2, Streptomyces aureofaciens NR-3, and Kitasatospora cystarginea NR-4 based on partial 16S rDNA sequences. A functional gene microarray containing gene probes for functions associated with biogeochemical cycling, metal homeostasis, and organic contaminant degradation showed little overlap among the four isolates. Fifteen of the genes were detected in all four isolates with only two of these related to metal resistance, specifically to tellurium. Each of the four isolates also displayed resistance to at least one of six antibiotics tested, with resistance to kanamycin, gentamycin, and ciprofloxacin observed in at least two of the isolates. Further characterization of S. aureofaciens NR-3 and K. cystarginea NR-4 demonstrated that both isolates expressed Ni tolerance constitutively. In addition, both were able to grow in higher concentrations of Ni at pH 6 as compared with pH 7 (42.6 and 8.5 mM Ni at pH 6 and 7, respectively). Tolerance to Cd, Co, and Zn was also examined in these two isolates; a similar pH-dependent metal tolerance was observed when grown with Co and Zn. Neither isolate was tolerant to Cd. These findings suggest that Ni is exerting a selection pressure at this site for metal-resistant actinomycetes.

Abstract  The effects of nitrate on the stability of reduced, immobilized uranium were evaluated in field experiments at a U.S. Department of Energy site in Oak Ridge, TN. Nitrate (2.0 mM) was injected into a reduced region of the subsurface containing high levels of previously immobilized U(IV). The nitrate was reduced to nitrite, ammonium, and nitrogen gas; sulfide levels decreased; and Fe(II) levels increased then deceased. Uranium remobilization occurred concomitant with nitrite formation, suggesting nitrate-dependent, iron-accelerated oxidation of U(IV). Bromide tracer results indicated changes in subsurface flowpaths likely due to gas formation and/or precipitate. Desorption-adsorption of uranium by the iron-rich sediment impacted uranium mobilization and sequestration. After rereduction of the subsurface through ethanol additions, background groundwater containing high levels of nitrate was allowed to enter the reduced test zone. Aqueous uranium concentrations increased then decreased. Clone library analyses of sediment samples revealed the presence of denitrifying bacteria that can oxidize elemental sulfur, H(2)S, Fe(II), and U(IV) (e.g., Thiobacillus spp.), and a decrease in relative abundance of bacteria that can reduce Fe(III) and sulfate. XANES analyses of sediment samples confirmed changes in uranium oxidation state. Addition of ethanol restored reduced conditions and triggered a short-term increase in Fe(II) and aqueous uranium, likely due to reductive dissolution of Fe(III) oxides and release of sorbed U(VI). After two months of intermittent ethanol addition, sulfide levels increased, and aqueous uranium concentrations gradually decreased to <0.1 microM.

Abstract  The U.S. Army is currently formulating a strategy for future kinetic energy penetrating materials. This report addresses the environmental and health issues associated with depleted uranium (DU) and tungsten penetrators. The objective of this study was to perform a preliminary assessment to investigate the environmental and health issues associated with DU and tungsten penetrator manufacturing, testing and recycle facilities. This work also included an assessment of requirements for decontamination of ammunition peculiar equipment (APE) and industrial plant equipment (IPE) at U.S. Army manufacturing sites. Combat issues were also addressed.

Abstract  The authors use the Los Alamos LAHET Code System (LCS)/CINDER'90 suite of codes in a variety of spallation neutron source applications to predict neutronic performance and as a basis for making engineering decisions. They have broadened their usage of the suite from designing LANSCE and the next generation of spallation neutron sources for materials science and nuclear physics research to designing a target system for Accelerator Production of Tritium and Accelerator Transmutation of Waste. While designing, they continue to validate the LCS/CINDER'90 code suite against experimental data whenever possible. In the following, they discuss comparisons between calculations and measurements for: integral neutron yields from a bare-target of lead; fertile-to-fissile conversion yields for thorium and depleted uranium targets; dose rates from the LANSCE tungsten target; energy deposition in a variety of light and heavy materials; and neutron spectra from LANSCE water and liquid hydrogen moderators. The accuracy with which the calculations reproduce experimental results is an indication of their confidence in the validity of their design calculations.

Abstract  Between 1965 and 1981, five objects (six naval reactor pressure vessels (RPVs) from four former Soviet Union submarines and a special containers from the icebreaker Lenin), each of which contained damaged spent nuclear fuel (SNF), were dumped in a variety of containments, using a number of sealing methods, at four sites in the Kara Sea. All objects were dumped at sites that varied in depth from 12 to 300 m. This paper examines the use of the long-lived radionuclides Ni-59, Tc-99, and U-236 encased within these objects to monitor the breakdown of the containments due to corrosion. Included are discussions of the radionuclide inventory and their release rate model, the estimated radionuclide mass in a typical seawater sample, and the potential for radionuclide measurement via Accelerator Mass Spectrometry (AMS).

Abstract  Facility Effluent Monitoring Plan determinations were conducted for the Westinghouse Hanford Company 300 Area facilities on the Hanford Site. These determinations have been prepared in accordance with A Guide For Preparing Hanford Site Facility Effluent Monitoring Plans. Sixteen Westinghouse Hanford Company facilities in the 300 Area were evaluated: 303 (A, B, C, E, F, G, J and K), 303 M, 306 E, 308, 309, 313, 333, 334 A, and the 340 Waste Handling Facility. The 303, 306, 313, 333, and 334 facilities Facility Effluent Monitoring Plan determinations were prepared by Columbia Energy and Environmental Services of Richland, Washington. The 340 Central Waste Complex determination was prepared by Bovay Northwest, Incorporated. The 308 and 309 facility determinations were prepared by Westinghouse Handford Company. Of the 16 facilities evaluated, 3 will require preparation of a Facility effluent Monitoring Plan: the 313 N Fuels Fabrication Support Building, 333 N Fuels fabrication Building, and the 340 Waste Handling Facility. 26 refs., 5 figs., 10 tabs.

Abstract  The discretization of the near field compartment model COMP23 used in e.g. the SR95 study is rather coarse, which results in a poor description of the first instationary phase of radionuclide release. For some nuclides the maximum release rates are somewhat overestimated. In this study, the discretization has been investigated in a systematic manner. First block 3 representing the bentonite outside the hole in the canister is divided into an increasing number of compartments. This block has in earlier calculations showed to be of major importance. In the SR95 study it was divided into three compartments and here it was increased to 6, 9, 12, and 15 compartments. The differences between the release rates are smaller for each increase, but also between 12 and 15 compartments there was some difference. The release rate decreases with increased number of compartments. It was decided to use six compartments, to achieve reasonable total number of compartments and thereby reasonable calculation times. The whole system was then studied in a corresponding way. The original discretization was found to be sufficient for all other blocks if only the total release is of interest. The final discretization was however proposed to include three compartments in block 5 and changed proportions between the size of the two compartments in block 4. The resulting discretization resulted in 19 compartments compared to the 14 compartments used in the SR95 study. The calculation time was recorded for all the studied cases. It was found that the calculation time increases in proportion to the square of the number of compartments. The calculation time increases about 20 % with the proposed discretization compared to the one earlier used.

Abstract  In the 1950s, additional high-level radioactive waste storage capacity was needed to accommodate the wastes that would result from the production of recovery of additional nuclear defense materials. To provide this additional waste storage capacity, the Hanford Site operating contractor developed a process to decontaminate aqueous wastes by precipitating radiocesium as an alkali nickel ferrocyanide; this process allowed disposal of the aqueous waste. The radiocesium scavenging process as developed was used to decontaminate (1) first-cycle bismuth phosphate (BiPO(sub 4)) wastes, (2) acidic wastes resulting from uranium recovery operations, and (3) the supernate from neutralized uranium recovery wastes. The radiocesium scavenging process was often coupled with other scavenging processes to remove radiostrontium and radiocobalt. Because all defense materials recovery processes used nitric acid solutions, all of the wastes contained nitrate, which is a strong oxidizer. The variety of wastes treated, and the occasional coupling of radiostrontium and radiocobalt scavenging processes with the radiocesium scavenging process, resulted in ferrocyanide-bearing wastes having many different compositions. In this report, we compare selected physical, chemical, and radiochemical properties measured for Tanks C-109 and C-112 wastes and selected physical and chemical properties of simulated ferrocyanide wastes to assess the representativeness of stimulants prepared by WHC.

Abstract  The following facility effluent monitoring plan determinations document the evaluations conducted for the Westinghouse Hanford Company 200 Area facilities (chemical processing, waste management, 222-S Laboratory, and laundry) on the Hanford Site in south central Washington State. These evaluations determined the need for facility effluent monitoring plans for the 200 Area facilities. The facility effluent monitoring plan determinations have been prepared in accordance with A Guide for Preparing Hanford Site Facility Effluent Monitoring Plans, WHC-EP-0438 (WHC 1991). The Plutonium/Uranium Extraction Plant and UO(sub 3) facility effluent monitoring plan determinations were prepared by Los Alamos Technical Associates, Richland, Washington. The Plutonium Finishing Plant, Transuranic Waste Storage and Assay Facility, T Plant, Tank Farms, Low Level Burial Grounds, and 222-S Laboratory determinations were prepared by Science Applications International Corporation of Richland, Washington. The B Plant Facility Effluent Monitoring Plan Determination was prepared by ERCE Environmental Services of Richland, Washington.

Abstract  Injection of organic carbon into the subsurface as an electron donor for bioremediation of redox-sensitive contaminants like uranium often leads to mineral transformation and biomass accumulation, both of which can alter the flow field and potentially bioremediation efficacy. This work combines reactive transport modeling with a column experiment and field measurements to understand the biogeochemical processes and to quantify the biomass and mineral transformation/accumulation during a bioremediation experiment at a uranium contaminated site near Rifle, Colorado. We use the reactive transport model CrunchFlow to explicitly simulate microbial community dynamics of iron and sulfate reducers, and their impacts on reaction rates. The column experiment shows clear evidence of mineral precipitation, primarily in the form of calcite and iron monosulfide. At the field scale, reactive transport simulations suggest that the biogeochemical reactions occur mostly close to the injection wells where acetate concentrations are highest, with mineral precipitate and biomass accumulation reaching as high as 1.5% of the pore space. This work shows that reactive transport modeling coupled with field data can bean effective tool for quantitative estimation of mineral transformation and biomass accumulation, thus improving the design of bioremediation strategies.

Abstract  The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, USA, acetate amendments initially promoted the growth of metal-reducing Geobacter species, followed by the growth of sulfate reducers, as observed previously. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater before the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the ameboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey-predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM RADIONUCLIDE SOIL PH OKAMOTO PLANT UPTAKE POLLUTION

Abstract  Several large-scale Chinese investigations on radiation epidemiology are overviewed, and a long-term cancer mortality study in high-background radiation areas (HBRA) is described. Some site-specific cancer incidences were higher among X-ray workers, and a higher mortality rate caused by lung cancer teas found among uranium and tin miners who started their work before 1970. An increase in cancer mortality rate was not found among workers in nuclear facilities and inhabitants who lived near the nuclear test site. A cancer mortality study was begun in 1972 in the HBRA whose radiation levels are about three times that of the nearby control areas (CA). About 1 million pet-son-years in HBRA and as many in CA were observed; no increase of site-specific cancer mortalities was found except the cancer of cervix uteri. Data for environmental carcinogens other than natural radiation and data on leukemia and thyroid nodularity were analyzed.

Abstract  Micronuclei can be used as markers of past radiation exposure, but few pertinent studies have dealt with alpha radiation. Here we report on micronuclei in lymphocytes from uranium miners, comparing some that are currently active and others that retired 15-20 years ago. Their radiation exposure is assumed to come mainly from radon and its decay products in the air breathed at the work place. Current miners showed a greater micronucleus frequency than former miners. This can be attributed to their recent radiation exposure, while the lower frequency in the former miners probably results from the disappearance of potentially micronucleus containing lymphocytes from the peripheral blood, which is known to occur with a half-life of about one year. For current miners there is a significant correlation between micronucleus frequency and effective dose received over the last 12 months. The dose at which a doubling of the micronucleus frequency is observed is around 10 mSv. This is a much smaller dose than would usually be expected to be detectable with this test, and raises a number of questions about the induction of micronuclei by alpha radiation from radon and its decay products.

Abstract  Inhalation of radon ((222)Rn) and daughter products are a major source of natural radiation exposure. Keeping this in view, seasonal indoor radon measurement studies have been carried out in 68 dwellings belonging to 17 residential areas in Alexandria city, Egypt. LR-115 Type 2 films were exposed for four seasons of 3 months each covering a period of 1 y for the measurement of indoor radon levels. Assuming an indoor occupancy factor of 0.8 and a factor of 0.4 for the equilibrium factor of radon indoors, it was found that the estimated annual average indoor radon concentration in the houses surveyed ranged from 45 ± 8 to 90 ± 13 Bq m(-3) with an overall average value of 65 ± 10 Bq m(-3). The observed annual average values are greater than the world average of 40 Bq m(-3). Seasonal variation of indoor radon shows that maximum radon concentrations were observed in the winter season, whereas minimum levels were observed in the summer season. The season/annual ratios for different type of dwellings varied from 1.54 to 2.50. The mean annual estimated effective dose received by the residents of the studied area was estimated to be 1.10 mSv. The annual estimated effective dose is less than the recommended action level (3-10 mSv y(-1)).

Abstract  Rational and balanced nutrition practice is not only an important determinant of health, but also a major factor in preventing and reducing the risk of chronic no communicable diseases. Eating disorders are the leading factors in the development of most non-communicable diseases, so this problem should be considered with health and social care, hygiene and preventive points of view. In connection with aforesaid it is necessary to study features of workers’ nutrition, to establish the factors and conditions, which influence on them, to exploit corresponding recommendation by optimization. Workers aged 35 – 50 took part in investigation of hygienic estimation of actual nutrition. In result of investigation of nutrition it was determinated that energetically asset of workers’ ration was lower than recommended standard, in average 2558 ±59 kkal. Consumption of proteins composed 86±2 g/day, for the account of them 14 % of the general caloric content of a ration are satisfied. The revealed misbalance in nutrition is essential factor of development risk of functional breaking of workers and demand obligatory correction.

Abstract  Mixed nitride fuels are being considered for advanced FBR, but very little is known about the thermodynamic properties of these fuels. For an overall composition of the nitride fuel with small amounts of oxygen and carbon impurities, thermodynamic properties, e.g. carbon activity and partial pressures of nitrogen, carbon-monoxide, plutonium and uranium, were calculated in present work. These calculations were based on standard Gibbs free energies of the binary compounds, present in this multi-component system (U,Pu)-C-N-O. For an over all composition of the fuel, stable phase-field was determined by minimization of the Gibbs free energy of the system. The fabrication experiences of various workers, reported in literature, have shown that depending on the impurity content, nitride fuel can exist in two phase fields, mono-nitride phase in equilibrium with sesquinitride phase or mono-nitride phase in equilibrium with dioxide phase. Therefore, in present calculations special attention was given to the thermodynamic behavior of these two phase-fields. A comparison of calculated thermodynamic properties indicated that nitride fuel with dioxide as second phase will be superior to the one with sesquinitride. (C) 1999 Elsevier Science B.V. All rights reserved.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. The Chernobyl accident and its resultant radioactive pollution of enormous areas led to long-term entrance of radionuclides into the human habitat. Among more than 200 radionuclides, the products of uranium fission in the reactor of the atomic power station, the isotopes of iodine, cesium, and strontium present the highest hazard. If iodine-131 virtually decayed by August, 1986, the long-lived isotopes of cesium and strontium will still stir the world public and scientists for many years. The au

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Analysis of most natural waters shows that 210Po, the last radioactive member of the uranium natural decay-series, is present at very low activities, usually lower than its insoluble precursor, 210Po. Recent papers, however, show that 210Po can exist at very high concentrations in groundwaters of some shallow aquifers. Concentrations of 210Po and 210Pb have been analyzed in the mineral spring waters of a high background region of Brazil: Aguas da Prata. The water samples were collected over a period of one year in springs used by the local population and tourists to the region. Concentrations ranging from 3.5 mBq l-1 to 7.80mBq l-1 to 3.98, respectively. Doses were estimated in order to evaluate the relative importance of the ingestion of such radionuclides. Based upon measured concentrations, effective doses up to 1.81 mSv y-1 were observed for 210Pb and 210Po. Doses up to 5.9 mSv y-1 for the ingestion of 210Pb and up to 1-9 mSv y-1 for the ingestion of 210Po wer

Abstract  This study was carried out to assess the radiological impact of Syrian phosphogypsum (PG) piles in the compartments of the surrounding ecosystem. Estimating the distribution of naturally occurring radionuclides (i.e. (226)Ra, (238)U, (232)Th, (210)Po and (210)Pb) in the raw materials, product and by-product of the Syrian phosphate fertilizer industry was essential. The data revealed that the concentrations of the radionuclides were enhanced in the treated phosphate ore. In PG, (226)Ra content had a mean activity of 318 Bq kg(-1). The uranium content in PG was low, ca. 33 Bq kg(-1), because uranium remained in the phosphoric acid produced. Over 80% of (232)Th, (210)Po and (210)Pb present partitioned in PG. The presence of PG piles did not increase significantly the concentration of (222)Rn or gamma rays exposure dose in the area studied. The annual effective dose was only 0.082 mSv y(-1). The geometric mean of total suspended air particulates (TSP) ca. 85 μg m(-3). The activity concentration of the radionuclides in filtrates and runoff waters were below the detection limits (ca. 0.15 mBq L(-1) for (238)U, 0.1 mBq L(-1) for (232)Th and 0.18 mBq L(-1) for both of (210)Po and (210)Pb); the concentration of the radionuclides in ground water samples and Qattina Lake were less than the permissible limits set for drinking water by the World Health Organisation, WHO, (10, 1 and 0.1 Bq L(-1) for (238)U, (232)Th and both of (210)Po and (210)Pb, respectively). Eastern sites soil samples of PG piles recorded the highest activity concentrations, i.e. 26, 33, 28, 61 and 40 Bq kg(-1) for (226)Ra, (238)U, (232)Th, (210)Po and (210)Pb, respectively, due to the prevailing western and north-western wind in the area, but remained within the natural levels reported in Syrian soil (13-32 Bq kg(-1) for (226)Ra, 24.9-62.2 Bq kg(-1) for (238)U and 10-32 Bq kg(-1) for (232)Th). The impact of PG piles on plants varied upon the plant species. Higher concentrations of the radionuclides were recorded for grass in comparison to broad-leaved plants. Among the species that grow naturally on PG piles, Inula, Ecballium and Polygonium may be radionuclides accumulators. A determined effort is needed at a national level to achieve a common and coherent approach to regulate PG piles or to consider it a resource material rather than waste or residue.