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BLIP production of Fe-52 and the Mn-52m generator

Description: Fe-52 (t 1/2 = 8.275 h) is the only radioisotope of iron with decay properties suitable for imaging applications (100% 169-keV and 112% annihilation gammas). It can also be used in a Fe-52/Mn-52m generator system as a source of Mn-52m (t 1/2 = 21.1m) which is a short-lived positron emitter (192.54% annihilation gammas). Clinically useful quantities of Fe-52 have been prepared at the Brookhaven Linac Isotope Producer (BLIP) by bombarding manganese or nickel targets with medium-energy protons. After chemical separation, Fe-52 is loaded onto a generator column from which carrier-free Mn-52m is eluted. The Mn-52m generator is potentially useful in positron emission computed tomography.
Date: January 1, 1979
Creator: Ku, T.H.; Richards, P.; Stang, L.G. & Prach, T.
Partner: UNT Libraries Government Documents Department

Hydrodynamical calculations of heavy-ion collisions. [Fragment elongation, differential cross sections]

Description: Heavy-ion collisions are studied by the use of two different approaches, depending upon whether the bombarding energy per nucleon yields collective velocities that are small or large compared to the nuclear sound speed. In low energy collisions the primary emphasis is on such fundamental aspects of nuclei as the nuclear potential energy of deformation, the nuclear inertia tensor, and the mechanism for nuclear dissipation. In high energy collisions the primary emphasis is on the nuclear equation of state, the fundamental relation specifying how the pressure depends upon density and internal energy. Some results are shown for differential cross sections and fragment elongation versus distance between mass centers. (JFP)
Date: September 1, 1977
Creator: Amsden, A. A.; Goldhaber, A. S.; Harlow, F. H.; Moeller, P.; Nix, J. R. & Sierk, A. J.
Partner: UNT Libraries Government Documents Department

Removal of radioactive contaminants from aqueous laboratory wastes by chemical treatment

Description: The following conclusions can be drawn from the studies reported. The presence of suspended matter (i.e., clay) in the spiked tapwater solution improved the plutonium removals; however, the addition of clinoptilolite to the plant raw feed did not provide any noticeable improvement for plutonium removal. The addition of powdered clinoptilolite to the regular treatment in the plant significantly improved the removal of /sup 137/Cs, but had little effect on plutonium or /sup 90/Sr removal. Magnesium sulfate-lime-TSP (trisodium phosphate) treatment in the plant performed adequately, but not as well as the regular ferric sulfate-lime-TSP treatment. However, magnesium appears to be an adequate alternate during occasions of non-typical influents. A large portion of the plutonium is associated with the suspended solids matter in the waste. Autoradiographs indicate that the plutonium is generally evenly distributed, with some occasional hot spots.
Date: January 1, 1976
Creator: Drago, J. A. & Buchholz, J. R.
Partner: UNT Libraries Government Documents Department

Thermal/fluid modeling of the response of saturated marine red clays to emplacement of nuclear waste

Description: This report discusses the heat and mass transport in marine red clay sediments being considered as a nuclear waste isolation medium. Development of two computer codes, one to determine temperature and convective velocity fields, the other to analyze the nuclide migration problem, is discussed and preliminary results from the codes reviewed. The calculations indicate that for a maximum allowable sediment/canister temperature range of 200 to 250/sup 0/C, the sediment can absorb about 1.5 kW initial power from waste in a 3 m long by 0.3 m diameter canister. The resulting fluid displacement due to convection is found to be small, less than 1 m. The migration of four nuclides, /sup 239/Pu, /sup 137/Cs, /sup 129/I, and /sup 99/Tc were computed for a canister buried 30 m deep in 60 m thick sediment. It was found that the /sup 239/Pu and /sup 137/Cs, which migrate as cations and have relatively high distribution coefficients, are essentially completely contained in the sediment. The anionic species, /sup 129/I and /sup 99/Tc, which have relatively low distribution coefficients, broke through the sediment in about 5000 years. The resultant peak injection rates which occur at about 15,000 years were extremely small (0.5 ..mu..Ci/year for /sup 129/I and 180 ..mu..Ci/year for /sup 99/Tc).
Date: January 1, 1979
Creator: McVey, D.F.; Gartling, D.K. & Russo, A.J.
Partner: UNT Libraries Government Documents Department

Radionuclide content of an exhumed canyon tank and neighboring soil

Description: To assess the long-term hazard potential associated with the burial of partially decontaminated process equipment, burial emplacements of equipment from an irradiated-fuel separations building (canyon) are being exhumed and examined. One piece of equipment, a Purex feed adjustment tank that was retired in 1957 from service in a hot canyon at the Savannah River Plant, has been exhumed and studied. This paper describes sampling of neighboring soil, tank exhumation, results of assay of soil and tank, and conclusions. Assays of the tank and soil show that only 1 mCi of /sup 137/Cs and 0.4 mCi (7 mg) of /sup 239/Pu remain on the surfaces of the tank; amounts of these radionuclides in neighboring soil are substantially less. Radionuclides from the contaminated surface of the tank migrated into neighboring soil. Of the three nuclides studied, /sup 90/Sr migrated most extensively, as observed previously. /sup 239/Pu contents of the tank and neighboring soil were less than the 10-nCi/g total transuranic nuclide content allowed under ERDA standards for burial of nonretrievable waste. This paper also describes plans for future studies including (1) exhumation of other equipment and (2) in-place lysimeter and laboratory-column tests for studying radionuclidic migration in soil.
Date: January 1, 1977
Creator: Holcomb, H. P.
Partner: UNT Libraries Government Documents Department

Methodology for the determination of environmental /sup 129/I and /sup 99/Tc

Description: The Savannah River Laboratory is using existing techniques and developing new methodology to determine the environmental impact of the Savannah River Plant with regard to /sup 129/I and /sup 99/Tc. /sup 129/I is determined by neutron activation after the method of Brauer. Activation products are quantified by ..gamma..-ray spectroscopy (Ge(Li)) following chemical isolation. /sup 125/I is used as a yield tracer. /sup 129/I amounts as low as 3.8 fCi can be determined with 30-minute counting times. An isotope dilution method for /sup 99/Tc based on a three-stage surface ionization mass spectrometer is being developed. Its chemical isolation scheme ends with the Tc loaded on a single ion-exchange bead for enhanced mass-spectrometric sensitivity. /sup 97/Tc will be used as a yield tracer. A lower limit of 0.2 fCi is sought. A modified method using liquid scintillation counting has determined /sup 99/Tc in some aqueous samples. These methods have confirmed that /sup 129/I and /sup 99/Tc can be highly mobile in the aqueous environment, establishing the need for monitoring.
Date: January 1, 1978
Creator: Anderson, T. J.
Partner: UNT Libraries Government Documents Department

Effects of interstitial solutes on the microstructures of self-ion irradiated vanadium

Description: Vanadium and vanadium containing 0.1 percent C, 0.4 percent C, 1.0 percent N, and 1.0 percent O were irradiated with 3-MeV /sup 51/V/sup +/ ions in the temperature range 650 to 880/sup 0/C to a dose level of approximately 20 dpa. The results show that nitrogen is most effective in controlling the void swelling. Carbon and oxygen also suppress the swelling considerably when compared with unalloyed vanadium. Except for V-1.0 percent N, all compositions exhibit a fine platelet precipitate with (012) habit at 650/sup 0/C. In the case of vanadium-carbon alloys, this phase persisted even at higher temperatures. Vanadium and V-1.0 percent O showed fine precipitation on dislocations and void surfaces at 880/sup 0/C. V-0.1 percent C exhibited a metastable (013) carbide precipitate at 880/sup 0/C, whereas V-0.4 percent C showed equilibrium V/sub 2/C phase with some (012) precipitates. This (012) precipitation was irradiation induced and was dependent upon the carbon concentration. V-1.0 percent N did not show any evidence of precipitation over the entire temperature range.
Date: January 1, 1976
Creator: Agarwal, S. C.; Potter, D. I. & Taylor, A.
Partner: UNT Libraries Government Documents Department

Relationship of dose rate and total dose to responses of continuously irradiated beagles

Description: Young-adult beagles were exposed continuously (22 hours/day) to /sup 60/Co ..gamma.. rays in a specially constructed facility. The exposure rates were either 5, 10, 17, or 35 R/day, and the exposures were terminated at either 600, 1400, 2000, or 4000 R. A total of 354 dogs were irradiated; 221 are still alive as long-term survivors, some after more than 2000 days. The data on survival of these dogs, coupled with data from similar preliminary experiments, allow an estimate of the LD/sub 50/ for ..gamma..-ray exposures given at a number of exposure rates. They also allow comparison of the relative importance of dose rate and total dose, and the interaction of these two variables, in the early and late effects after protracted irradiation. The LD/sub 50/ for the beagle increases from 258 rad delivered at 15 R/minute to approximately 3000 rad at 10 R/day. Over this entire range, the LD/sub 50/ is dependent upon hematopoietic damage. At 5 R/day and less, no meaningful LD/sub 50/ can be determined; there is nearly normal continued hematopoietic function, survival is prolonged, and the dogs manifest varied individual responses in other organ systems. Although the experiment is not complete, interim data allow several important conclusions. Terminated exposures, while not as effective as radiation continued until death, can produce myelogenous leukemia at the same exposure rate, 10 R/day. More importantly, at the same total accumulated dose, lower exposure rates are more damaging than higher rates on the basis of the rate and degree of hematological recovery that occurs after termination of irradiation. Thus, the rate of hematologic depression, the nadir of the depression, and the rate of recovery are dependent upon exposure rate; the latter is inversely related and the former two are directly related to exposure rate.
Date: January 1, 1978
Creator: Fritz, T. E.; Norris, W. P.; Tolle, D. V.; Seed, T. M.; Poole, C. M.; Lombard, L. S. et al.
Partner: UNT Libraries Government Documents Department

Resonance-averaged (n,. gamma. ) spectra and their applications to nuclear structure. [J,. pi. , 2 and 24 keV]

Description: Because they populate final states without regard to the details of the nucleonic configurations, neutron-capture ..gamma.. rays are ideally suited for locating essentially all the low lying nuclear states whose spins lie within a few units of that of the capturing state. With the reduction of the Porter--Thomas fluctuations through the use of neutrons having an energy distribution broad enough to average over a finite (and large) number of capture resonances, the primary capture ..gamma..-ray intensities can provide rather definite spin-parity information for those states which they are observed to populate. The power of these studies is greatly enhanced through the analysis of such resonance-averaged spectra at two distinct neutron energies, approx. 2 and approx. 24 keV, obtained from Sc and Fe neutron ''filters'', respectively. The use of resonance-averaged primary ..gamma..-ray spectra as a tool for low-energy nuclear spectroscopy is discussed and its strengths and limitations pointed out. Examples are drawn from studies of 2- and 24-keV neutron capture in samples of /sup 154/ /sup 156/ /sup 157/ /sup 158/Gd and /sup 238/U. 20 references.
Date: January 1, 1978
Creator: Reich, C.W.
Partner: UNT Libraries Government Documents Department

Model to project dose-to-man from buried solid waste

Description: To plan for the postoperational surveillance and control of the Savannah River Plant solid waste burial site, a model is being developed to simulate movement of radionuclides from buried solid waste through the environment to man. Results from the study of the model will be used to validate current operating limits for burial and to establish criteria for future surveillance and control. A preliminary model has been formulated to estimate the rate and extent of /sup 90/Sr movement through a set of aquatic (ground water, creeks, and river) and terrestrial (vegetation, animals, and dust) pathways. Estimates based on pessimistic assumptions show that drinking water from the shallow ground water table in the burial region is the critical pathway for dose-to-man. Current and planned experimental programs to refine model parameters will be presented.
Date: January 1, 1977
Creator: Wilhite, E. L.
Partner: UNT Libraries Government Documents Department

Preparations for high-level defense waste immobilization at Savannah River Plant

Description: Methods are being developed to immobilize Savannah River Plant (SRP) wastes in high-integrity glass forms. The waste forms will be suitable for storage in an on-site facility or for shipment to an off-site repository. Alkaline wastes produced in SRP separations plants are currently stored in large, carbon-steel tanks. These wastes consist of a water-soluble fraction (salt cake and supernatant liquor) and an insoluble sludge. The water-soluble fraction contains most of the /sup 137/Cs and the insoluble sludge contains most of the /sup 90/Sr, waste actinides, and other fission products. /sup 90/Sr and /sup 137/Cs are the most hazardous radionuclides in aged waste. A conceptual solidification process has been developed from laboratory tests with both actual and simulated waste. Engineering design studies are in progress. First, wastes are removed as a slurry from the waste tanks. The sludge is separated from the supernate, and then /sup 137/Cs is removed from the clarified supernate by ion exchange. The resulting decontaminated supernate is evaporated to a salt for bulk storage. In the second part of the process, /sup 137/Cs is mixed with sludge and the mixture is calcined and then solidified in borosilicate glass. Off-gas from the calciner and glass melter is treated to ensure that no hazardous materials are released to the atmosphere.
Date: January 1, 1978
Creator: Wiley, J.R.
Partner: UNT Libraries Government Documents Department

Using local momentum to disentangle angular distributions. [Optical model, DWBA]

Description: Optical model elastic and DWBA transfer angular distributions are studied by isolating their positive and negative deflection angle components. The local angular momentum of these amplitudes allows isolation of the regions of angular momentum space that are contributing to the different angular regions of the cross sections. This information can be employed to isolate features of the cross sections arising from orbiting, reflection, Coulomb rainbows, nuclear rainbows, Regge poles, etc. Specifically it is shown that the inner contribution to typical heavy-ion forward-angle elastic scattering is in the shadow of the nuclear rainbow and further that transfer angular distributions contain separate inner and outer contributions. Before discussing results, the idea of a ''local momentum'' is introduced and the decomposition of angular distributions into their positive and negative deflection angle components is briefly described. Results are shown for the reaction /sup 60/Ni(/sup 13/C,/sup 12/C)/sup 61/Ni at E = 60.8 MeV and for the elastic scattering of /sup 13/C on /sup 60/Ni at the same incident energy. (SDF)
Date: March 1, 1976
Creator: Fuller, R. C. & Moffa, P. J.
Partner: UNT Libraries Government Documents Department

Development of positron emitting radionuclides for imaging with improved positron detectors. [/sup 82/Rb, /sup 62/Zn, /sup 64/Cu, /sup 67/Ga]

Description: Recent advances in positron cameras and positron ring detectors for transverse section reconstruction have created renewed interest in positron emitting radionuclides. This paper reports on: generator-produced /sup 82/Rb; cyclotron-produced /sup 62/Zn; and reactor-produced /sup 64/Cu. Investigation of the /sup 82/Sr (25 d)--/sup 82/Rb (75 s) generator determined the elution characteristics for Bio-Rex 70, a weakly acidic carboxylic cation exchanger, using 2% NaCl as the eluent. The yield of /sup 82/Rb and the breakthrough of /sup 82/Sr were determined for newly prepared columns and for long term elution conditions. Spallation-produced /sup 82/Sr was used to charge a compact /sup 82/Rb generator to obtain multi-millicurie amounts of /sup 82/Rb for myocardial imaging. Zinc accumulates in the islet cells of the pancreas and in the prostate. Zinc-62 was produced by protons on Cu foil and separated by column chromatography. Zinc-62 was administered as the amino acid chelates and as the ZnCl/sub 2/ to tumor and normal animals. Tissue distribution was determined for various times after intravenous injection. Pancreas-liver images of /sup 62/Zn-histidine uptake were obtained in animals with the gamma camera and the liver uptake of /sup 99m/Tc sulfur colloid was computer subtracted to image the pancreas alone. The positron camera imaged uptake of /sup 62/Zn-histidine in the prostate of a dog at 20 h. /sup 64/Cu was chelated to asparagine, a requirement of leukemic cells, and administered to lymphoma mice. Uptake in tumor and various tissues was determined and compared with the uptake of /sup 67/Ga citrate under the same conditions. /sup 64/Cu-asparagine had better tumor-to-soft tissue ratios than /sup 67/Ga-citrate.
Date: October 1, 1976
Creator: Yano, Y.
Partner: UNT Libraries Government Documents Department

Emission computed axial tomography. [Comparison of /sup 99m/Tc with. gamma. camera with /sup 68/Ga and ring of scintillation counters]

Description: Computed transverse section emission tomography using /sup 99m/Tc with the Anger camera is compared to positron annihilation coincident detection using a ring of crystals and /sup 68/Ga. It is concluded that positron computed section imaging has a tenfold increase in sensitivity over multiple-view imaging with the gamma camera which gives multiple sections but requires camera or patient rotation.
Date: October 1976
Creator: Budinger, Thomas F.; Derenzo, Stephen E.; Gullberg, Grant T.; Greenberg, William L. & Huesman, Ronald H.
Partner: UNT Libraries Government Documents Department

Moessbauer spectroscopic investigation of radiation damage of Co(III)-HEDTA and Fe(III)-HEDTA complexes

Description: The chemical effect of the electron capture of /sup 57/Co isotope in solid organic complexes was studied as a function of dimeric and monomeric structures of the same molecule as well as a function of the environment of the molecule in crystalline solid and frozen solutions of the same molecule. The /sup 57/Co was prepared in the forms of CO(III)-HEDTA and Fe(III)-HEDTA. In crystalline /sup 57/Co(III)-HEDTA dimer the daughter /sup 57/Fe of two valency states was observed in the ratio 75 percent to 25 percent. Results of the study indicate that the stabilization of /sup 57/Fe/sup n+/ is influenced not only by the immediate environment of the decayed nuclei but also by the environment of the whole molecule. (LK)
Date: January 1, 1976
Creator: Nagy, A. G.; Dezsi, I. & Hillman, M.
Partner: UNT Libraries Government Documents Department

Indocyanine green labeled with /sup 123/I for dynamic studies of the hepato-biliary system. [/sup 131/I, /sup 125/I]

Description: This report summarizes the results to develop an iodine-123 labeled agent for dynamic studies of the hepato-biliary system. Iodine-123 is an ideal nuclide for radiopharmaceuticals, because of its short half-life (T/sub /sup 1///sub 2// = 13.3 hr); its decay with a high abundance (83%) of 159 keV photons; and the reduced patient radiation exposure (a factor of 100 less than iodine-131). Indocyanine green, a tricarbanocyanine dye, was introduced by Heseltine and co-workers in 1956, has several characteristics which suggested that iodine-123 labeled ICG might be potentially useful for hepatic functional evaluation. The plasma clearance and biliary excretion kinetics of /sup 123/I-ICG (in dogs) will be compared to /sup 131/I-rose bengal and bromosulphalein labeled with iodine-125.
Date: January 1, 1975
Creator: Lambrecht, R. M.; Ansari, A. N.; Wolf, A. P. & Atkins, H. L.
Partner: UNT Libraries Government Documents Department

Physical basis for large forward cross sections in /sup 60/Ni(/sup 18/O,/sup 16/O) reaction

Description: Experiments on the reaction /sup 60/Ni(/sup 18/O,/sup 16/O)/sup 62/Ni revealed an unexpectedly large forward cross section for production of the ground state, in contrast with an expected grazing peaked distribution. This has most recently been interpreted in terms of a surface transparent optical potential. In the inverse experiment, it is known that /sup 18/O is produced in its 2/sup +/ state with larger cross section than the ground state. This suggests that the above ground state reaction can also be produced with appreciable probability through the excitation of /sup 18/O in the incident channel, with a subsequent transfer of two neutrons to form the ground state of /sup 62/Ni. It is found that by including this process together with the direct transfer, the experimental data can be accounted for. The parameters of the optical potential employed are chosen so as to reproduce both the elastic and inelastic cross sections, and are of the normal strong absorbing type with no surface transparency. It is concluded that the projectile excitation is the physical process involved in the large forward cross section. In addition the interference of the direct and indirect processes can give rise to a minimum beyond the grazing peak followed by a secondary maximum, some indication of which can be found in the experiments on neighboring nuclei. The quantal deflection function is employed in a discussion of the S matrix and angular distribution emerging from this calculation and of the surface transparent potential parametrization of the effect. 5 figures, 1 table.
Date: March 1, 1976
Creator: Glendenning, N. K. & Wolschin, G.
Partner: UNT Libraries Government Documents Department