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Comparative biogeochemical behaviors of iron-55 and stable iron in the marine environment

Description: Studies of atmospheric aerosols have demonstrated that much of the /sup 55/Fe associated with the aerosol input to the oceans is present as either an amorphous or hydrous iron oxide or as very small particulate species attached to the surfaces of the large aerosol particles. By comparison, nearly all of the stable iron is bound in the mineral phase of aerosol particles. This difference in the chemical and physical forms of the radioactive and stable iron isotopes results in the /sup 55/Fe being more biologically available than is the stable iron. This difference in availability is responsible for the transfer of a much higher specific activity /sup 55/Fe to certain ocean organisms and man relative to the specific activity of the total aerosol or of sea water. This differential biological uptake of the radioactive element and its stable element counterpart points out that natural levels of stable elements in the marine environment may not effectively dilute radioelements or other stable elements of anthropogenic sources. The effectiveness of dilution by natural sources depends on the chemical and physical forms of the materials in both the source terms and the receiving environments. The large difference in specific activities of /sup 55/Fe in aerosols and sea water relative to ocean organisms reflects the independent behaviors of /sup 55/Fe and stable iron.
Date: February 6, 1978
Creator: Weimer, W.C.; Langford, J.C. & Jenkins, C.E.
Partner: UNT Libraries Government Documents Department

Monte Carlo simulation of turbulent atmospheric transport and comparisons with experimental data. [/sup 41/Ar continuously emitted from BNL reactor to atmosphere]

Description: In a previous paper Peterson presented measurements on the /sup 41/Ar emitted continuously into the atmosphere from a reactor at the Brookhaven National Laboratory. Here, calculated results obtained with the Monte Carlo atmospheric transport model of Watson and Barr are presented and compared with the experimental data. The measured quantities with which comparisons are made are: the position north of Brookhaven where the maximum /sup 41/Ar concentration occurred for specific values of x (east of Brookhaven) and t, time; the standard deviation, sigma/sub y/, of the /sup 41/Ar concentration about the position of maximum concentration for specific values of x and t; and a quantity that is proportional to the maximum /sup 41/Ar concentration for specific values of x and t. The calculated results are in moderately good agreement with the experimental data at most distances (less than or equal to 300 km) and most times for which data are available.
Date: March 1, 1978
Creator: Alsmiller, F. S.; Alsmiller, Jr., R. G.; Bertini, H. W. & Begovich, C. L.
Partner: UNT Libraries Government Documents Department

Radiochemical analyses of samples from beneath a solid radioactive waste disposal pit at Los Alamos, New Mexico

Description: Solid radioactive wastes are disposed of by burial in pits excavated in rhyolite tuff at the Los Alamos Scientific Laboratory (LASL). Contaminants in the waste include fission products, uranium, and transuranic elements. In 1976, horizontal core holes were drilled beneath a waste disposal pit that was used from 1963 to 1966. Samples of the core were analyzed for gross alpha, gross beta, total uranium, /sup 90/Sr, /sup 137/Cs, /sup 238/Pu, /sup 239/ /sup 240/Pu, and /sup 241/Am. The measured gross alpha, gross beta, and uranium concentrations were above minimum detection limits; concentrations of the remaining radionuclides, all of which are man-made isotopes, were below the minimum detection limits. Statistical comparisons were made of the gross alpha, gross beta, and uranium data to identify any significant variations from natural concentrations in the tuff. The comparisons demonstrated that none of the radioactivity detected in the samples can be attributed to migration from the disposal pit.
Date: June 1, 1980
Creator: Purtymun, W.D.; Rogers, M.A. & Wheeler, M.L.
Partner: UNT Libraries Government Documents Department

Plasma Separation Process: Betacell (BCELL) code: User's manual. [Bipolar barrier junction]

Description: The emergence of clearly defined applications for (small or large) amounts of long-life and reliable power sources has given the design and production of betavoltaic systems a new life. Moreover, because of the availability of the plasma separation program, (PSP) at TRW, it is now possible to separate the most desirable radioisotopes for betacell power generating devices. A computer code, named BCELL, has been developed to model the betavoltaic concept by utilizing the available up-to-date source/cell parameters. In this program, attempts have been made to determine the betacell energy device maximum efficiency, degradation due to the emitting source radiation and source/cell lifetime power reduction processes. Additionally, comparison is made between the Schottky and PN junction devices for betacell battery design purposes. Certain computer code runs have been made to determine the JV distribution function and the upper limit of the betacell generated power for specified energy sources. A Ni beta emitting radioisotope was used for the energy source and certain semiconductors were used for the converter subsystem of the betacell system. Some results for a Promethium source are also given here for comparison. 16 refs.
Date: November 13, 1987
Creator: Taherzadeh, M.
Partner: UNT Libraries Government Documents Department

Properties of radioactive wastes and waste containers. Quarterly progress report, April-June 1980

Description: A study was initiated to determine the effect of varying V/S (the ratio of the waste form volume to its surface area) on the leachability of radioisotopes incorported in cement forms. Cesium-137 and strontium-85 mixed with a simulated formulation of waste derived from forced recirculation evaporator bottoms of LWR's were solidified in portland II cement. The V/S ratios of the forms varied from 0.41 to 2.77. The resulting forms were leached using a modified IAEA procedure. Leaching data indicate an inverse relationship between the amount of leached radioactivity and V/S value. Experiments were undertaken to determine the degree of desorption of Cs-137 initially adsorbed on cation organic ion exchange resins upon mixing with cement paste and during the plastic phase of the curing process. Portland II and lumnite cements were used as the solidification agents. Twenty seven percent of the Cs-137 was removed from the ion exchange resins after two hours of contact with portland II cement, whereas, 43% of the activity was removed from the resins after the same contact period with lumnite cement. 15 refs., 12 figs., 4 tabs.
Date: August 1, 1980
Creator: Morcos, N. & Weiss, A.J.
Partner: UNT Libraries Government Documents Department

Polyketones and polysulfones for conservation in the ethylene polymer industry. Progress report No. 6, July-September 1979

Description: The characterization study on ethylene-CO (Et-CO) copolymers was concluded. The copolymers were prepared at various levels of CO composition, and with several methods loss of catalysis, including free-radical, metallic, and /sup 60/Co irradiation. Et-CO copolymers exhibit crystallinity related to the alternating polyketone structure which increasees logarithmically with CO content over the range 28% to 49% CO. The melting point increases in essentially the same manner as crystallinity. The structure of the copolymers is independent of the type of catalysis used. Highly crystalline copolymers showed discoloration and loss of crystallinity at 140/sup 0/C, whether in air or N/sub 2/. Discoloration is severe at 210/sup 0/C, and after heating at 280/sup 0/C for 1 h, essentially all crystallinity was lost. Press molding of highly crystalline copolymer at 260/sup 0/C for 5 minutes showed 38.8% loss of crystallinity and appearance of H/sub 2/O and olefinic unsaturation. Reaction kinetic studies on the low-pressure (< 5 atm) gas-phase copolymerization of ethylene - SO/sub 2/ (Et-SO/sub 2/) mixtures at a dose rate of 0.54 Mrad/h and at 10 to 13/sup 0/C were continued. Recharging a reaction system repeatedly with a mixture containing 19.2 mole % S/sub 2/ initially resulted in a general increase in G-value from 4.60 x 10/sup 4/ to 7.10 x 10/sup 4/ molecules/100eV and a factor of 4.6 decrease in reaction time for the attainment of peak rate and G-value. Low-pressure (< 5 atm) gas-phase /sup 60/Co gamma copolymerization at a dose rate of 0.56 Mrad/h and at 10 to 13/sup 0/C of a 1-butene-SO/sub 2/ mixture of approximately equimolar composition resulted in peak and overall G-values of 340 and 156, respectively, and product of nearly equimolar composition. For safety reasons the experimental radiation facility for conducting the copolymer studies was relocated to another building and a 5300 Ci /sup 60/Co gamma radiation ...
Date: January 1, 1980
Creator: Steinberg, M.; Johnson, R.; Elling, D.; Cordes, W. & Goodman, D.
Partner: UNT Libraries Government Documents Department

Polysulfones for conservation in the ethylene polymer industry. Progress report No. 7, October 1979-March 1980

Description: Ethylene-SO/sub 2/ polysulfone copolymers were prepared by /sup 60/Co gamma radiation, as well as by electron-beam radiation and by thermocatalysis, as a means of incorporating a polluting waste product material such as SO/sub 2/ into ethylene polymers for the purpose of conserving ethylene feedstock. Ethylene-SO/sub 2/ copolymer was pressure molded into discs which had a high degree of hardness as well as partial transparency, but were also very brittle. Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA) indicated peak decomposition at 350/sup 0/C. Long term heat aging tests showed stability to 175/sup 0/C and initiation of decomposition at 200/sup 0/C in air after 900 h. Decomposition became severe as the temperature was increased to 300/sup 0/C. The activation energies for decomposition were 57.3 and 56.8 kcal/mole for liquid-phase and gas-phase formed copolymers, respectively. The ethylene-SO/sub 2/ copolymer was modified by the incorporation of monomeric styrene, 2-vinyl pyridine, 4-vinyl pyridine, and N-vinyl pyrrolidine. A summary of characterization studies by INCO which includes solubility, infra-red and x-ray analysis of the ethylene-SO/sub 2/ copolymer and with additives are presented.
Date: June 1, 1980
Creator: Steinberg, M.; Johnson, R.; Elling, D.; Bernstein, P. & Varker, A.E.
Partner: UNT Libraries Government Documents Department

Recent experiments at Brookhaven: level structure of N = 86 isotones /sup 156/Yb and /sup 150/Gd

Description: States of the N = 86 isotones /sup 156/Yb and /sup 150/Gd have been studied by means of the /sup 144/Sm(/sup 16/O,4n)/sup 156/Yb, /sup 113/In(/sup 46/Ti,p2n)/sup 156/Yb, and /sup 124/Sn(/sup 30/Si,4n)/sup 150/Gd reactions. Levels have been established to spin 36 h-bar and over 12.5 MeV in excitation in /sup 150/Gd and to beyond spin 25 h-bar in /sup 156/Yb. The systematics of levels in the N = 86 isotones from /sup 150/Gd to /sup 156/Yb are described, and the near-spherical shell model description for states in this region to near spin 30 h-bar is discussed. A T/sub 1/2/ = 6 ns, 72-keV isomeric transition in /sup 156/Yb has been discovered, and an E1 multipolarity is assigned to this transition. The spin-parity of the isomeric state is established as 11/sup -/. 6 figures.
Date: January 1, 1980
Creator: Sunyar, A W
Partner: UNT Libraries Government Documents Department

Brookhaven National Laboratory site report for calendar year 1988

Description: Brookhaven National Laboratory (BNL) is managed by Associated Universities Inc. (AUI). AUI was formed in 1946 by a group of nine universities whose purpose was to create and manage a laboratory in the Northeast in order to advance scientific research in areas of interest to universities, industry, and government. On January 31, 1947, the contract for BNL was approved by the Manhattan District of the Army Corps of Engineers and BNL was established on the former Camp Upton army camp. 54 refs., 21 figs., 78 tabs.
Date: June 1, 1989
Creator: Miltenberger, R.P.; Royce, B.A. & Naidu, J.R.
Partner: UNT Libraries Government Documents Department

Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 1. Northeast Pacific pelagic red clay

Description: To provide information useful for determining the biogeochemical cycling of corrosion products in the benthic boundary layer of the deep ocean, neutron-activated stainless steel was exposed to seawater and to Northeast Pacific red clay under aerobic and non-oxygenated conditions. This report describes the trace metal geochemistry of the sediment and the chemical speciation of the corrosion products. The sediments generally consisted of reddish-brown clay at the surface grading to a dark-brown transition zone below which mottled olive-gray clay prevailed. Neutron-irradiated 347 stainless steel specimens were exposed to seawater and sediment slurry under aerobic and non-oxygenated conditions for 108 days. The presence of aerated sediment more than doubled the amount of corrosion products released compared to aerated seawater and non-oxygenated sediment treatments. The distribution of /sup 60/Co released from the stainless steel exposed to aerated seawater show that almost 70% of /sup 60/Co activity became associated with suspended particulate matter. No detectable /sup 60/Co activity was present in the soluble, readily dissolved, or inorganic or weakly complexed fractions of aerated sediment which had been used to treat neutron-activated stainless steel. Almost 50% of the /sup 60/Co activity was extracted in the combined soluble, easily dissolved, adsorbed, and organically complexed fractions from the non-oxygenated sediment treatment indicating that this much of the corrosion products may be initially released in ionic form.
Date: March 1, 1982
Creator: Schmidt, R.L.
Partner: UNT Libraries Government Documents Department

Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 2. Sequim Bay clayey silt

Description: This report describes laboratory experiments in which neutron-activated 347 stainless steel specimens were exposed to clayey silt from Sequim Bay, Washington. The properties and trace metal geochemistry of the sediment and the amounts of corrosion products that were released under oxic and reduced conditions and their distribution among different chemical fractions of the sediment are discussed. The distributions of Cr, Mn, Fe, Ni and Cu among different chemical forms in the Sequim Bay sediment show that DTPA removed <10% of extractable Cr, Fe and Mn, approx. 20% of extractable Ni and approx. 30% of extractable Cu. The inorganic fraction (material soluble in 2.5% acetic acid) accounted for approx. 30% of total extractable Mn and approx. 10% or less of Cr, Fe, Ni and Cu. Major portions of Cr and Cu, and a large amount of Fe were in the organic fraction. Extractable Mn, Fe and Ni were associated with hydrous oxides likely as coatings on the mineral substrate of the sediment. No Co was detectable in any of the extracts. (PSB)
Date: April 1, 1982
Creator: Schmidt, R.L.
Partner: UNT Libraries Government Documents Department

Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 4: Hatteras abyssal red clay

Description: A study in which neutron-activated 347 stainless steel was exposed to surficial sediment from a site in the Hatteras Abyssal Plain of the Northwest Atlantic Ocean is described. This sediment consists of approx. 20% CaCO/sub 3/, which could lead to the formation of calcareous scale on the metal surface and reduce the corrosion rate. The distribution of indigenous metals among different chemical fractions shows that extractable Cr, Mn, Fe, Co, and Zn were associated with amorphous Mn and Fe oxides. Most of the remaining extractable Cr, and about a third of the extractable Cu appear to have been weakly complexed. Major fractions (25 to 36%) of extractable Mn, Co and Ni were present as adsorbed cations. Organic complexation appears to account for a large amount of extractable Fe, Ni, Cu and Zn. Neutron-activated 347 stainless steel specimens were exposed to sediment slurry under aerobic and non-oxygenated conditions for a period of 94 days. The redox potential measurements for air-sparged and N/sub 2/, CO/sub 2/-sparged sediment slurries were +410 and +60 mv, respectively. The presence of 0/sub 2/ produced increased amounts of corrosion products. Chemical extraction showed that relatively labile substances constituted about 84% of the /sup 60/Co activity released in aerated sediment. Relatively labile substances constitute about 82% of the total /sup 60/Co activity released under non-oxygenated conditions. A large fraction of /sup 60/Co which was in the soluble or easily dissolved forms under non-oxygenated conditions appears to have been more strongly adsorbed to the sediment under aerated conditions.
Date: July 1, 1982
Creator: Schmidt, R.L.
Partner: UNT Libraries Government Documents Department

Fully automated radiochemical preparation system for gamma-spectroscopy on fission products and the study of the intruder and vibrational levels in /sup 83/Se

Description: AUTOBATCH was developed to provide a usable source of short-lived neutron-rich nuclides through chemical preparation of the sample from fission products for detailed gamma-ray spectroscopy, which would complement the output of on-line isotope separators. With AUTOBATCH the gamma rays following the ..beta../sup -/ decay of /sup 83/As were studied to determine the ground state spin and parity of /sup 83/As to be 5/2/sup -/; the absolute intensity of the ..beta../sup -/ branch from /sup 83/As to /sup 83/Se/sup m/ to be 0.3%; the absolute intensity of the ground state ..beta../sup -/ branch from /sup 83/Se/sup m/ to /sup 83/Br to be 39%; the halflife of the 5/2/sub 1//sup +/ level to be 3.2 ns; and the structure of /sup 83/Se/sub 49/. Results are used to show that the intruder structure which had been previously observed in the odd mass /sub 49/In isotopes could be observed in the N = 49 isotones. The observed structure is discussed in terms of the unified model calculations of Heyde which has been used to describe the intruder structure in the indium nuclei. The intruder structure is most strongly developed, not at core mid-shell, /sup 89/Zr/sub 49/, but rather at core mid-sub-shell /sup 83/Se. This difference is qualitatively understood to be due to the blocking of collectivity by the Z = 40 subshell closure which prevents the intruder structure from occurring in /sup 87/Sr/sub 49/ and /sup 89/Zr/sub 49/.
Date: October 1, 1983
Creator: Lien, O.G. III
Partner: UNT Libraries Government Documents Department

Sediment and radionuclide transport in rivers. Phase 3. Field sampling program for Cattaraugus and Buttermilk Creeks, New York

Description: A field sampling program was conducted on Cattaraugus and Buttermilk Creeks, New York during April 1979 to investigate the transport of radionuclides in surface waters as part of a continuing program to provide data for application and verification of Pacific Northwest Laboratory&#x27;s (PNL) sediment and radionuclide transport model, SERATRA. Bed sediment, suspended sediment and water samples were collected during unsteady flow conditions over a 45 mile reach of stream channel. Radiological analysis of these samples included gamma ray spectrometry analysis, and radiochemical separation and analysis of Sr-90, Pu-238, Pu-239, 240, Am-241 and Cm-244. Tritium analysis was also performed on water samples. Based on the evaluation of radionuclide levels in Cattaraugus and Buttermilk Creeks, the Nuclear Fuel Services facility at West Valley, New York, may be the source of Cs-137, Sr-90, Cs-134, Co-60, Pu-238, Pu-239, 240, Am-241, Cm-244 and tritium found in the bed sediment, suspended sediment and water of Buttermilk and Cattaraugus Creeks. This field sampling effort was the last of a three phase program to collect hydrologic and radiologic data at different flow conditions.
Date: August 1, 1982
Creator: Ecker, R.M.; Walters, W.H. & Onishi, Y.
Partner: UNT Libraries Government Documents Department

FY 1992 task plans for the Hanford Environmental Dose Reconstruction Project

Description: Phase 1 of the HEDR Project was designed to develop and demonstrate a method for estimating radiation doses people may have received from Hanford Site operations since 1944. The method researchers developed relied on a variety of measured and reconstructed data as input to a modular computer model that generates dose estimates and their uncertainties. As part of Phase 1, researchers used the reconstructed data and computer model to calculate preliminary dose estimates for populations from limited radionuclides, in a limited geographical area and time period. Phase 1 ended in FY 1990. In February 1991, the TSP decided to shift the project planning approach away from phases--which were centered around completion of major portions of technical activities--to individual fiscal years (FYs), which span October of one year through September of the next. Therefore, activities that were previously designated to occur in phases are now designated in an integrated schedule to occur in one or more of the next fiscal years into FY 1995. Task plans are updated every 6 months. In FY 1992, scientists will continue to improve Phase 1 data and models to calculate more accurate and precise dose estimates. The plan for FY 1992 has been prepared based on activities and budgets approved by the Technical Steering Panel (TSP) at its meeting on August 19--20, 1991. The activities can be divided into four categories: (1) model and data evaluation activities, (2) additional dose estimates, (3) model and data development activities, and (4) technical and communication support. 3 figs., 2 tabs.
Date: October 1, 1991
Partner: UNT Libraries Government Documents Department

Energy and technology review, May--June 1991

Description: This issue of Energy and Technology Review describes two powerful analytical tools that use ion-beam techniques to make contributions to an astonishing range of fundamental problems. We characterize these techniques -- accelerator mass spectrometry (AMS) and ion microbeam analysis -- under the common rubric of accelerator microanalysis. Each of these tools is used in disciplines ranging from anthropology to zoology. The rich diversity of applications is reason enough to dedicate an entire issue to these impressive tools. Most of the applications are already under investigation here at LLNL. One section in this issue explains how the high sensitivity of AMS offers the possibility of one day tailoring drugs to the needs of individual patients. Other articles describe the broad potential of AMS in environmental monitoring, so critical to the well-being of the public, and explain how it offers a precise timepiece that can help us understand our prehistoric past and, perhaps, one day help make accurate predictions for future global climate changes. The ion microbeam facility at LLNL may give the United States a competitive edge in advanced production techniques for microdevices. An article on the economic impact of microanalytical tools explains that other industries, too, may benefit during this era when we are facing tough competition from international markets. This is also an article on the history, development, and key advantages of AMS and ion microbeam analysis. Of prime importance for research is that they are nondestructive of many samples, allowing valuable (or irreplaceable) materials to be analyzed. These techniques also make it possible to study unique, small-sample experiments and may allow the first-time imaging of some living materials or functioning systems.
Date: January 1, 1991
Creator: Johnson, K.C.; de Vore, L.; Gleason, K.; Highstone, H.; Kroopnick, H.; Sanford, N.M. et al.
Partner: UNT Libraries Government Documents Department

Management of radioactive waste gases from the nuclear fuel cycle. Volume I. Comparison of alternatives

Description: Alternatives were compared for collection and fixation of radioactive waste gases released during normal operation of the nuclear fuel cycle, and for transportation and storage/disposal of the resulting waste forms. The study used a numerical rating scheme to evaluate and compare the alternatives for krypton-85, iodine-129, and carbon-14; whereas a subjective evaluation, based on published reports and engineering judgement, was made for transportation and storage/disposal options. Based on these evaluations, certain alternatives are recommended for an integrated scheme for waste management of each of the subject waste gases. Phase II of this project, which is concerned with the development of performance criteria for the waste forms associated with the subject gases, will be completed by the end of 1980. This work will be documented as Volume II of this report.
Date: December 1, 1980
Creator: Evans, A.G.; Prout, W.E.; Buckner, J.T. & Buckner, M.R.
Partner: UNT Libraries Government Documents Department

Environmental behavior of technetium in soil and vegetation: implications for radiological impact assessment

Description: Significant radiological exposures have been estimated for hypothetical atmospheric releases of Tc-99 from gaseous diffusion facilities when vegetation-to-soil concentration ratios representative of laboratory experiments are substituted for generic default values assumed in current regulatory models. To test the relevancy of these laboratory ratios, field investigations were conducted to obtain measurements of the vegetation-to-soil concentration ratio for Tc-99 in samples collected near operating gaseous diffusion facilities and to observe the dynamic behavior of technetium in soil and vegetation following a single application of a sprayed solution of /sup 95m/TcO/sub 4//sup -/ Comparison of observed field concentration ratios and calculated steady-state concentration ratios with ratios obtained from previous laboratory experiments indicates that concentration ratios obtained from field data are one to two orders of magnitude less than those obtained from the laboratory. Furthermore, a substantial accumulation of technetium in soil and vegetation may not occur over long periods of time, since concentrations of technetium in both environmental media were observed to decrease with time subsequent to initial application of /sup 95m/TcO/sub 4//sup -/.
Date: April 1, 1982
Creator: Hoffman, F.O.
Partner: UNT Libraries Government Documents Department

Evaluation of resonance parameters for neutron interaction with iron isotopes for energies up to 400 keV

Description: The evaluation of the resolved resonance parameters of iron isotopes 54, 56, and 57 in the neutron energy region below 400 keV is documented. Estimates of the uncertainties in the resonance parameters and correlation between the partial widths GAMMA/sub n/ and GAMMA/sub ..gamma../ are given when significant. Some details about the procedures used to evaluate the resonance parameters, their uncertainties, and correlations are reported. This evaluation was performed for the general-purpose file of the Evaluated Nuclear Data File (ENDF/B-V MAT 1326). 4 figures, 7 tables.
Date: September 1, 1980
Creator: Perey, C.M. & Perey, F.G.
Partner: UNT Libraries Government Documents Department

Modeling study of gaseous Rn-222, Xe-133, and He-4 for uranium exploration

Description: This work presents one-dimensional mathematical models to simulate the transport of gaseous radon-222 (Rn-222), xenon-133 (Xe-133), and helium-4 (He-4) away from uranium ore deposits. The resulting concentrations of indicator nuclides in the overburden are used to infer the detectability of ore deposits by emanation methods. In the case of homogeneous, non-radioactive formations, Rn-222 and some of its daughter products are calculated to be detectable at distances of several tens of meters from a planar uranium ore deposit (1 m tickness, 0.6% U/sub 3/O/sub 8/, 20% emanation). Models of He-4 diffuson in rock yield highly uncertain results because measurements of diffusion coefficients in actual rock types are lacking and because the flux of helium from deep within the earth is generally unknown. Comparisons of model results to field data suggest that He-4 diffusion coefficients of 10/sup -4/ to 10/sup -5/ cm/sup 2//sec are appropriate. It is speculated that moisture in the rock column could reduce the coefficient significantly compared to the dry-soil case. Inhomogeneity in rock formations is simulated by a multiple-layer model. A comparison of fluorometric uranium data to gamma spectra measurements suggests the migration and deposition of Ra-226 near the water table. Modeling results are improved when this process is taken into account. A constant soil gas velocity of 1 x 10/sup -4/ cm/sec causes indicator concentrations to change by several orders of magnitude. If steady upward soil gas motion exists in nature, the detectability of uranium ore by emanation methods will be significantly different from that indicated by pure diffusion models. Barometric influences on gas transport are simulated by time-dependent numerical models.
Date: January 1, 1980
Creator: Jeter, H.W.
Partner: UNT Libraries Government Documents Department

Early and continuing effects of combined alpha and beta irradiation of the lung:

Description: This report summarizes an inhalation exposure experiment that concerns early and continuing effects of combined alpha and beta irradiation of the lung of rats. Both morbidity at 18 months and mortality within 18 months after exposure were examined for rats exposed to the beta-emitter /sup 147/Pm, the alpha-emitter /sup 238/Pu, or both combined. The results were used to validate hazard-function models that were developed (1)for pulmonary functional morbidity at 18 months and (2) for lethality from radiation pneumonitis and pulmonary fibrosis within 18 months. Both models were found to adequately predict the experimental observations after combined chronic alpha and beta irradiation of the lung. A relative biological effectiveness of approximately 7 was obtained for /sup 238/Pu alpha radiation compared to /sup 147/Pm beta radiation for both pulmonary functional morbidity and lethality from radiation pneumonitis and pulmonary fibrosis. 12 refs., 16 figs., 11 tabs.
Date: March 1, 1988
Creator: Scott, B.R.; Hahn, F.F.; Snipes, M.B.; Newton, G.J.; Eidson, A.F.; Mauderly, J.L. et al.
Partner: UNT Libraries Government Documents Department

Tracer study of batch sedimentation. [Resin beads - 45 and 62. mu. m in diameter]

Description: The initial particle-concentration profile in batch settling tests was assessed and determined to be uniform. Two sets of data for batch-settling tests using cobalt-57-traced ion-exchange resin beads (45 and 62 ..mu..m in diameter) were compared with existing theories and models. A single suspended-solids zone was observed in agreement with the predictions of Dixon; the Richardson-Zaki correlation predicted the settling velocity as a function of void fraction to within 5%. Studies with a bimodal particle-size distribution of equal fraction of 45- and 62-..mu..m particles showed that the larger particles settled at the same velocity as in a single-particle-size distribution but that the smaller ones settled slower than for a single-particle-size distribution at a given void fraction. The ratio of the settling velocity of the smaller particles in a bimodal-particle-size distribution u/sub b/ to the settling velocity of these particles in a single particle-size distribution u/sub s/ was correlated by raising to the (3.78 +- 0.47) power the effective void fraction of the resulting upper settling zone containing only the smaller particles.
Date: April 1, 1982
Creator: Bigot, P.C. & Lee, A.H.
Partner: UNT Libraries Government Documents Department

Nuclear research with heavy ions

Description: This report discusses the following topics: Asymmetric fission of {sup 149}Tb* from the finite-range, rotating-liquid-drop model: mean total kinetic energies for binary fragmentation; charged-particle evaporation from hot composite nuclei: evidence over a broad Z range for distortions from cold nuclear profiles; the role of reversed kinematics and double kinematic solutions in nuclear reactions studies; production of intermediate-mass-fragments in the reaction {sup 98}Mo + {sup 51}V at an excitation energy E* = 224-MeV; emission of light charged particles in the reaction 344-MeV {sup 28}Si + {sup 121}Sb; continued developments of the statistical evaporation code LILITA{ }N90; and planning for heavy-ion-collision studies at very high energies: the STAR collaboration at RHIC.
Date: August 1, 1991
Creator: Kaplan, M.
Partner: UNT Libraries Government Documents Department

Studies of heavy ion reactions and transuranic nuclei. Progress report, August 1, 1979-July 31, 1980. [Univ. of Rochester, New York, 8/1/79-7/31/80]

Description: The study of heavy-ion reaction mechanisms at the SuperHILAC and LAMPF is reported. Preprints of five articles and manuscripts of four recent conference papers are given, along with complete citations of publications and a list of personnel. Significant work was performed in the following areas: the bombarding energy dependence of the /sup 209/Bi + /sup 136/Xe reaction; the fragment yields for specific Z and A for projectile-like fragments produced in the reaction of 8.3-MeV/u /sup 56/Fe ions with targets of /sup 56/Fe, /sup 165/Ho, /sup 209/Bi, and /sup 238/U; and time distributions of fragments from delayed fission after muon capture for muonic /sup 235/U, /sup 238/U, /sup 237/Np, /sup 239/Pu, and /sup 242/Pu. (RWR)
Date: July 1, 1980
Creator: Huizenga, J.R.
Partner: UNT Libraries Government Documents Department