Download or read book Medical Isotope Production Without Highly Enriched Uranium written by National Research Council and published by National Academies Press. This book was released on 2009-06-27 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the product of a congressionally mandated study to examine the feasibility of eliminating the use of highly enriched uranium (HEU2) in reactor fuel, reactor targets, and medical isotope production facilities. The book focuses primarily on the use of HEU for the production of the medical isotope molybdenum-99 (Mo-99), whose decay product, technetium-99m3 (Tc-99m), is used in the majority of medical diagnostic imaging procedures in the United States, and secondarily on the use of HEU for research and test reactor fuel. The supply of Mo-99 in the U.S. is likely to be unreliable until newer production sources come online. The reliability of the current supply system is an important medical isotope concern; this book concludes that achieving a cost difference of less than 10 percent in facilities that will need to convert from HEU- to LEU-based Mo-99 production is much less important than is reliability of supply.
Download or read book Removal of Technetium 99 from Simulated Oak Ridge National Laboratory Newly Generated Liquid Low Level Waste written by and published by . This book was released on 1995 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report laboratory investigations on treatment options for the removal of the radionuclide 99{Tc} (as the pertechnetate anion, {Tc}O4−) from simulated Oak Ridge National Laboratory Newly Generated Liquid Low-Level Waste. The waste stimulant is alkaline (pH 12-13), containing sodium carbonate ((approximately)0.10 mot/L) and sodium hydroxide ((approximately) 0.125 mol/L), plus a modest concentration of sodium nitrate ((approximately)0.06 mol/L). Several organic resin anion exchange media were tested; Dowex{trademark} 1-X-8 and Reillex{trademark} HPQ resins were notably effective (with equilibrium distribution coefficients (approximately)2,000 mL/g, as-received basis). We also tested steel wool as a reagent to chemically reduce and sorb 99Tc. At pH values above (approximately)10, the iron surface was passivated and became ineffective as a reagent for technetium; however, as the test solution pH value was adjusted to near-neutrality (e.g., pH 8-9), the steel was noted to be more effective than the organic resins tested. In dynamic flow conditions, steel wool packed in a column was noted to continuously leak (approximately)1--3% of the amount of 99{Tc} activity in the feed solution, although no additional increase in eluent activity was noted for the duration of the testing ((approximately)1200 bed volumes of (approximately)0.11 mg/L 99{Tc} flowed at a rate equivalent to (approximately)0.5 gal/min/ft2 of column cross sectional area). Although no breakthrough was noted (other than the 1--3 % continuous ''bleed'' noted previously) during the column operation ((approximately) 2 weeks), the steel in the column was deteriorated, causing plugging and erratic flow toward the end of the testing interval.
Download or read book Electrochemical Reduction Removal of Technetium 99 from Hanford Tank Wastes written by Wesley E. Lawrence and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molybdenum 99 for Medical Imaging written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-11-28 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The decay product of the medical isotope molybdenum-99 (Mo-99), technetium-99m (Tc-99m), and associated medical isotopes iodine-131 (I-131) and xenon-133 (Xe-133) are used worldwide for medical diagnostic imaging or therapy. The United States consumes about half of the world's supply of Mo-99, but there has been no domestic (i.e., U.S.-based) production of this isotope since the late 1980s. The United States imports Mo-99 for domestic use from Australia, Canada, Europe, and South Africa. Mo-99 and Tc-99m cannot be stockpiled for use because of their short half-lives. Consequently, they must be routinely produced and delivered to medical imaging centers. Almost all Mo-99 for medical use is produced by irradiating highly enriched uranium (HEU) targets in research reactors, several of which are over 50 years old and are approaching the end of their operating lives. Unanticipated and extended shutdowns of some of these old reactors have resulted in severe Mo-99 supply shortages in the United States and other countries. Some of these shortages have disrupted the delivery of medical care. Molybdenum-99 for Medical Imaging examines the production and utilization of Mo-99 and associated medical isotopes, and provides recommendations for medical use.
Download or read book Technetium in the Environment written by G. Desmet and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of technetium (in 1937, by Perrier and Segre), technetium-99 and technetium-99m have become most familiar in the specialised literature, the behaviour of the former being of concern regarding its health impact, the latter having been used intensively in medical tests for many years. The knowledge of the characteristics and behaviour of this element in nature is currently increasing exponentially. It has become clear, however, that there is still a serious shortage of information needed to assess properly its burden and impact on man and his environment. Technetium may indeed be released from nuclear installations or as a waste product from medical applications. It is generally considered to be highly mobile as the anion TcOi, but it is also suspected to be readily reduced in soils and metabolised in living beings into lower oxidation states. The seminar was planned to analyse thoroughly the experimental results obtained up to now and to make recommendations of specific issues requiring further research. This book presents the papers of the different sessions in the order of presentation, and the conclusions drawn by three discussion groups which dealt separately with: problems of sources and distribution of man-made technetium and its radiological consequences; the chemical behaviour of technetium in different ecosystems; biochemical reactions and binding with macromolecules in various life systems. vi Preface The editors, together with the Programme Committee of the Seminar, wish to express their gratitude to the chairmen of the different sessions for their summary of the group discussions.
Download or read book Removal of Technetium from Alkaline Nuclear waste Media by a Solvent extraction Process Using Crown Ethers written by and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crown ethers dissolved in suitably modified aliphatic kerosene diluents can be employed to extract technetium as pertechnetate anion (TcO4−) with good extraction ratios from realistic simulants of radioactive alkaline nitrate waste. The modifiers utilized are non-halogenated and non-volatile, and the technetium can be removed from the solvent by stripping using water. The crown ethers bis-4,4(prime)(5(prime))[(tert-butyl)cyclohexano]-18-crown-6 (di-t-BuCH18C6) and dicyclohexano-18-crown-6 (DCH18C6) provide stronger TcO4− extraction than dicyclohexano-21-crown-7 and 4-tert-butylcyclohexano 15-crown-5. Whereas DCH18C6 provides somewhat higher TcO4− extraction ratios than the more lipophilic di-t-BuCH18C6 derivative, the latter was selected for further study owing to its lower distribution to the aqueous phase. Particularly good extraction and stripping results were obtained with di-t-BuCH 18C6 at 0.02 M in a 2:1 vol/vol blend of tributyl phosphate and Isopar{reg_sign} M. Using this solvent, 98.9% of the technetium contained (at 6 x 10−5 M) in a Double-Shell Slurry Feed (DSSF) Hanford tank waste simulant was removed following two cross-current extraction contacts. Two cross-current stripping contacts with deionized water afforded removal of 99.1% of the technetium from the organic solvent.
Download or read book Technetium Removal from Hanford and Savannah River Site Actual Tank Waste Supernates with SuperLig R 639 Resin written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: SuperLig(R) 639 elutable, organic resin has been selected for technetium (as pertechnetate ion) removal from Hanford Site radioactive waste samples as part of the River Protection Project - Waste Treatment Plant (RPP-WTP) design. In support of the RPP-WTP flow sheet development, column tests have been performed at the Savannah River Technology Center with SuperLig(R) 639 resin using actual Hanford Site tank waste samples. The resin was shown to be highly effective at pertechnetate removal from these caustic, high-sodium, aqueous waste samples. Pertechnetate ion was subsequently eluted from the columns with water. An additional column test conducted on a Savannah River Site waste sample revealed exceptional performance, presumably due to the fact that lower concentrations of competing anions (primarily nitrate) were present in the sample.
Download or read book Radioactive Waste Processing and Disposal written by U.S. Nuclear Regulatory Commission and published by . This book was released on 1980 with total page 908 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Evaluation of an Ion exchange Method for the Removal of Technetium 99 from Groundwater written by Wanda Sue Elliott and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Removal of Technetium from Hanford Tank 241 AP 101 written by Ingrid E. Burgeson and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Removal of Technetium Carbon Tetrachloride and Metals from DOE Properties written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research is to prepare, characterize, and evaluate new materials for the removal of technetium (Tc) compounds, halogenated organics, and other troublesome metals from DOE waste streams and contaminated areas. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (Cr, Hg, Pb, Cd) and Re (as a surrogate for Tc) to insoluble forms faster and with higher efficiency than does unsupported iron. Liquid-liquid extraction methods are also being developed for quantitative removal of Cs from tetraphenylborate salt mixtures, which are generated in waste processing at Savannah River, and conversion to vitrifiable inorganic Cs salts.
Download or read book Multiple Ion Exchange Column Tests for Technetium Removal from Hanford Tank Waste Supernate written by and published by . This book was released on 2004 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five cycles of loading, elution, and regeneration were performed to remove technetium from a Hanford waste sample retrieved from Tank 241-AW-101 using SuperLig 639 resin. The waste sample was diluted to 4.95 M Na plus and then was processed to remove 137Cs through dual ion exchange columns each containing 15 mL of SuperLig 644. To remove 99Tc, the cesium decontaminated solution was processed downwards through two ion exchange columns, each containing 12 mL of SuperLig 639 resin. The columns, designated as lead and lag, each had an inside diameter of 1.45 cm and a height of 30 cm. The columns were loaded in series, but were eluted and then regenerated separately. The average technetium loading for the cycles was 250 BV at 10 percent breakthrough. There was no significant difference in the loading performances among the five cycles. The percent removal of 99Tc was greater than 99.94 percent and the average decontamination factor (DF) was approximately 1.7 x 103. Approximately 99 percent of the 99Tc loaded on the resin was eluted with less than 15 BV of de-ionized water at 65 degrees C.
Download or read book Process for Removing Technetium from Iron and Other Metals written by and published by . This book was released on 1997 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technetium is a radioactive product of the nuclear fission process. During reprocessing of spent or partially spent fuel from nuclear reactors, the technetium can be released and contaminate other, otherwise good, metals. A specific example is equipment in gaseous diffusion uranium enrichment cascades which have been used to process fuel which was returned from reactors, so-called reactor returns. These returns contained volatile technetium compounds which contaminated the metals in the equipment. Present regulations require that technetium be removed before the metal can be re-used at non-radioactive sites. Removing the technetium from contaminated metals has two desirable results. First, the large amount of nonradioactive metal produced by the process herein described can be recycled at a much lower cost than virgin metal can be produced. Second, large amounts of radioactively contaminated metal can be reduced to relatively small amounts of radioactive slag and large amounts of essentially uncontaminated metal. A new and improved process for removing technetium from iron and other metals is described in which between 1/10 atom % and 5 atom % of manganese is added to the contaminated metal in order to replace the technetium.
Download or read book Technetium Removal Column Flow Testing with Alkaline High Salt Radioactive Tank Waste written by David L. Blanchard (Jr.) and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intermediate Scale Ion Exchange Removal of Technetium from Savannah River Site Tank 44 F Supernate Solution written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the Hanford River Protection Project waste Treatment facility design contracted to BNFL, Inc., a sample of Savannah River Site (SRS) Tank 4 F waste solution was treated for the removal of technetium (as pertechnetate ion). Interest in treating the SRS sample for Tc removal resulted from the similarity between the Tank 44 F supernate composition and Hanford Envelope A supernate solutions. The Tank 44 F sample was available as a by-product of tests already conducted at the Savannah River Technology Center (SRTC) as part of the Alternative Salt Disposition Program for treatment of SRS wastes. Testing of the SRS sample resulted in considerable cost-savings since it was not necessary to ship a sample of Hanford supernate to SRS.
Download or read book Technetium Removal from Aqueous Wastes written by P. A. Fletcher and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tank Closure and Waste Management for the Hanford Site written by and published by . This book was released on 2012 with total page 1098 pages. Available in PDF, EPUB and Kindle. Book excerpt:
