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Nuclear Fuels, Nuclear Structure, the Mass Defect, and Radioactive Decay
Published in Robert E. Masterson, Introduction to Nuclear Reactor Physics, 2017
The half-life of Actinium-227, which is a key component of the U-235 decay chain, is known to be 21.78 years. Suppose that there are 3.23 × 107 atoms of U-235 to each atom of Actinium-227 in a sample of radioactive material that is recovered from the ocean floor. What is the projected half-life of U-235 using the atomic ratios in this sample?
Properties of the Elements and Inorganic Compounds
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
and other agents. Anyone working with the elements and certain of their compounds should become thoroughly familiar with the proper safeguards to be taken. Information on specific hazards and recommended exposure limits may also be found in Section 16. Reference should also be made to publications such as the following: 1. Code of Federal Regulations, Title 29, Labor. With additions found in issues of the Federal Register. 2. Code of Federal Regulations, Title 10, Energy. With additions found in issues of the Federal Register. (Published by the U.S. Government Printing Office. Supt. of Documents.) 3. Occupational Safety and Health Reporter (latest edition with amendments and corrections), Bureau of National Affairs, Washington, D.C. 4. Atomic Energy Law Reporter, Commerce Clearing House, Chicago, IL. 5. Nuclear Regulation Reporter, Commerce Clearing House, Chicago, IL. 6. TLVs Threshold Limit Values for Chemical Substances and Physical Agents is issued annually by the American Conference of Governmental Industrial Hygienists, Cincinnati, Ohio. 7. The Sigma Aldrich Library of Regulatory and Safety Data. Vol. 3, Robert E. Lenga and Kristine L. Volonpal, Sigma Chemical Co. and Aldrich Chemical Co., Inc. 1993. 8. Hazardous Chemicals Desk Reference, 4th ed., Richard J. Lewis, Sr., John Wiley & Sons, New York, 1997. 9. Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, 3rd ed., Noyes Publications, 2001/2. 10. Sax's Dangerous Properties of Industrial Materials, Richard J. Lewis and N. Irving Sax, John Wiley & Sons, New York, 1999. 11. World Wide Limits for Toxic and Hazardous Chemicals in Air, Water, and Soil, Marshall Sittig, Noyes Publishers. The prices of elements as indicated in this article are intended to be only a rough guide. Prices may vary, over time, widely with supplier, quantity, and purity. The density of gases is given in grams per liter at 0 °C and a pressure of 1 atm. Actinium -- (Gr. aktis, aktinos, beam or ray), Ac; at. wt. (227); at. no. 89; m.p. 1050 °C, b.p. 3198 °C; sp. gr. 10.07 (calc.). Discovered by Andre Debierne in 1899 and independently by F. Giesel in 1902. Occurs naturally in association with uranium minerals. Thirty-four isotopes and isomers are now recognized. All are radioactive. Actinium-227, a decay product of uranium-235, is an alpha and beta emitter with a 21.77-year half-life. Its principal decay products are thorium-227 (18.72day half-life), radium-223 (11.4-day half-life), and a number of short-lived products including radon, bismuth, polonium, and lead isotopes. In equilibrium with its decay products, it is a powerful source of alpha rays. Actinium metal has been prepared by the reduction of actinium fluoride with lithium vapor at about 1100 to 1300 °C. The chemical behavior of actinium is similar to that of the rare earths, particularly lanthanum. Purified actinium comes into equilibrium with its decay products at the end of 185 days, and then decays according to its 21.77-year half-life. It is about 150 times as active as radium, making it of value in the production of neutrons. Actinium-225, with a purity of 99%, is available from the Oak
Sorption of Rare-earth Elements and Ac on DN resin with HCl, HClO4, CH3COOH, CCl3COOH
Published in Solvent Extraction and Ion Exchange, 2018
Genko Marinov Marinov, Atanaska Pavlova Marinova, Maria Milinova Milanova, Steffen Happel, Dimitar Veselinov Karaivanov, Dmitry Vladimirovich Filosofov
The radioactive tracers 225Ac, 88Y, 139Ce, 143Pm, 149Eu, 146Gd, 155Tb, 167Tm, 169Yb, and 173Lu were used in this research, allowing all measurements to be performed by gamma spectrometry. All Ln isotopes were produced via proton irradiation of a metallic Ta target on the Phasotron (at Joint Institute for Nuclear Research (JINR), Dubna, Russian Federation). Ac was obtained from a 229Th – 225Ra – 225Ac generator. The actinium is obtained by elution from phosphorus ion-exchange resin with mineral acids and then purified with the use of small-particle cation-exchange resin. To analyse the radionuclides, an Ortec γ-ray spectrometer with an HPGe detector system and Samar software was used. The dead time of the detector was always kept below 7%.[26–28]