DOCSLIB.ORG

Zeolite Membranes for Krypton/Xenon Separation from Spent Nuclear Fuel Reprocessing Off-Gas

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Zeolite Membranes for Krypton/Xenon Separation from Spent Nuclear Fuel Reprocessing Off-Gas Project No. 14-6309 Zeolite Membranes for Krypton/Xenon Separation from Spent Nuclear Fuel Reprocessing Off-Gas Fuel Cycle Research and Development Sankar Nair Georgia Institute of Technology Patricia Paviet, Federal POC Robert Jubin, Technical POC Final Project Report (Oct 2014-Dec 2017) Project: Zeolite Membranes for Krypton/Xenon Separation from Spent Nuclear Fuel Reprocessing Off-Gas (Project 14-6309, PICS WP NU-14-GA-GT-0201-04, CID NE0008298) List of Graduate and Undergraduate Students Supporting Project Yeon Hye Kwon, South Korea, Chemical Engineering, expected graduation in 2018, pursuing Ph.D. Byunghyun Min, South Korea, Chemical Engineering, expected graduation in 2019, pursuing Ph.D. Shaowei Yang, China, Chemical Engineering, Post-doctoral Fellow. Kiwon Eum, South Korea, Chemical Engineering, graduated in 2016, Ph.D. Emily Benjamin, USA, Chemical Engineering, graduated in 2016, B.S. Christine Kiang, USA, Chemical Engineering, expected graduation in 2018, pursuing B.S. Abstract The overall focus of this project is to develop and understand SAPO-34 zeolitic membranes that can separate mixtures of radioisotope krypton-85 and xenon released as off-gases during used nuclear fuel recycling. The primary advantage of separating 85Kr from Xe is to reduce the volume of radioactive waste for storage. The second advantage is the revenue generated from the sale of high-purity Xe. Zeolite membranes are attractive because of their much lower energy requirements relative to cryogenic distillation, and their high resistance to radiation degradation. We report the detailed study of silicoaluminophosphate zeolite SAPO-34 materials and membranes for this application, due to hypothesized favorable molecular sieving properties. In the 3-year Mission Support project, we developed a novel, high-performance, low- energy intensity, lower-cost zeolite membrane process for Kr/Xe separation during SNF processing; and investigated the underlying molecular adsorption and transport processes in both ‘idealized’ and ‘realistic’ operating conditions to develop reliable synthesis-structure-property relationships for such membranes. Adsorption and diffusion measurements on SAPO-34 crystals indicate their potential for use in Kr-Xe separation membranes, but also highlight competing effects of adsorption and diffusion selectivity. SAPO-34 membranes synthesized on α-alumina substrates via steam-assisted conversion seeding and hydrothermal growth are characterized in detail, with Kr permeances 26 GPU and ideal Kr/Xe selectivities >20 at 298 K after thickness reduction. Post-synthesis cation exchange shows large (>50%) increases in selectivity at ambient or slight sub-ambient conditions. In addition, we confirm that SAPO-34 membrane is stable under radiation exposure and the impact of radiation exposure on membrane performance would not be substantial. We also successfully synthesized hollow-fiber SAPO-34 membranes with the same performance levels as the disk-type and tubular membranes. This important development will allow a very compact and low-cost Kr/Xe separation system. Finally, a detailed process calculation for techno-economic analysis was performed by integrating Maxwell-Stefan model into cross-flow membrane system, in order to estimate the required number of membrane stages and the total cost. Background of Program Objectives Nuclear energy is an efficient and economical means of providing carbon-free energy, but requires effective management of radioactive waste products [1, 2]. As part of the overall process for recycling spent nuclear fuel (SNF), it is necessary to develop technologies of advanced and cost-effective SNF recycle and waste minimization for long-term energy security. Recycling of zircaloy (the second largest mass in SNF) has been investigated to maximize reuse and minimize waste volume requiring geological disposal. This involves an integrated process (e.g., Figure 1), including chemical zircaloy decladding, removal of fission products by voloxidation, and dissolution. separate the off-gases formed during the fission of uranium and plutonium in nuclear power reactors [3]. Separating and capturing each gas is critical to reduce the volume of radioactive Figure 1: Process diagram for off-gas treatment. Red arrows indicate solid and aqueous streams (uranium and plutonium), blue arrows are gas streams (process off-gas). Kr/Xe separation, which is the main focus of the proposed work, is highlighted at the bottom left. waste for storage. The long-lived radioisotope 85Kr and stable 136Xe are released as process off- gas and Kr/Xe separation is challenging because they are chemically inert and physically very similar. Based on data from a US national laboratory, the Kr/Xe mixture is approximately 10/90 by volume [4] and hence the separation of Kr would reduce the volume of radioactive 85Kr waste by a factor of 10. One way of separating them is by cryogenic distillation [3, 5] wherein they are condensed out as pure streams at very low temperature (Kr boiling point: -153°C, Xe: -108°C). However, cryogenic distillation has intensive power requirements and a large system volume, resulting in high capital, operating, and disposal costs. Membrane-based separation using radiation-stable materials is an attractive alternative [6, 7], if membranes with sufficient separation properties are successfully fabricated and scaled up. Chabazite (CHA) framework type zeolites have a nominal pore size of 0.38 nm, which is in between the kinetic diameters of Kr (0.36 nm) and Xe (0.396 nm), and it has been recently shown that silicoaluminophosphate CHA (also referred to as SAPO-34) membranes are good candidates for Kr/Xe separation [7, 8]. Main Objectives and Results Our proposed work was divided into 5 main objectives. In this report we describe our accomplishments in each objective over the project performance period . Objective 1: Understanding and control of intrinsic Kr and Xe adsorption/diffusion properties of SAPO-34. The main goals of this work were to synthesize SAPO-34 crystals of appropriate dimensions and obtain the adsorption and diffusion properties of Kr and Xe as a function of temperature and pressure from a well-defined set of SAPO-34 materials of tuned SixAlyPzO2 (x + y + z = 1) compositions and containing exchanged metal cations. Due to limited information on intrinsic Kr and Xe adsorption and diffusion properties which determines the membrane performance, we synthesized SAPO-34 crystals and obtained its adsorption and diffusion parameters using pressure-decay measurement over 10 – 400 kPa and at 308 – 343 K. Figure 2. Single-gas Kr and Xe adsorption isotherms on (a) H-SAPO-34 at different temperatures and (b) H-SAPO-34 and ion-exchanged M-SAPO-34 materials. Symbols: experimental data, dashed lines: Langmuir fits. SAPO-34 crystals were synthesized from a reactant molar composition of 1.0 Al2O3:1.0 P2O5:0.32 SiO2:1.0 TEAOH:1.6 CHA (cyclohexylamine):52 H2O with aluminum hydroxide (Al(OH)3) as the Al source. The average crystal sizes and standard deviations are 10.7±2.3 µm (SAPO-34-CHA) and the edge dimension of the cuboid crystals is used as the effective crystal diameter, since this achieves the required equivalence of surface area-to-volume ratio with a spherical crystal of the same diameter. The crystals were immersed in the ethanol solution of acetate salts of monovalent (Li+, Na+, and K+) cations for ion exchange. Single-component gas adsorption isotherms of Kr and Xe were collected and fitted to Langmuir model (Equation 1) by a global fit of the isotherms over all temperatures (Figure 2a), 푞 푏 푝 푞 = 푠푎푡 (1) 1 + 푏 푝 where q is the adsorbate concentration in the sample, qsat the saturation coverage, p the pressure and b the Langmuir constant which can be expressed in terms of the enthalpy of o adsorption (ΔHads) and the pre-exponential entropic factor b = exp (ΔSads/R). The enthalpy and entropy of Xe adsorption are larger than those of Kr, leading to the stronger adsorption of Xe. Table 1 also shows the M-S diffusion parameters obtained from the kinetic uptake data. The diffusion activation energy of Kr is much lower than that of Xe which is consistent with the kinetic diameter of Kr and Xe in relation to the crystallographic pore size of SAPO-34. Table 1. Langmuir Adsorption Parameters and Maxwell-Stefan Diffusion parameters for Kr and Xe in H- SAPO-34 0 qsat -ΔHads b0 D MS Ea Gas (mmol/g) (kJ/mol) (*10-6 kPa-1) (*10-10 m2/s) (kJ/mol) Kr 6.1 ± 0.2 16.1 ± 0.3 1.4 ± 0.3 2.5 ± 0.3 13.9 ± 1.0 Xe 4.2 ± 0.1 18.3 ± 0.4 3.8 ± 0.2 2.0 ± 0.1 23.6 ± 0.8 Adsorption isotherms on H-SAPO-34 and the three ion-exchanged M-SAPO-34 materials were measured at 298 K over 10-300 kPa (Figure 2b) which showed all the materials preferentially adsorb Xe over Kr. Table 2 summarizes the textural properties obtained by N2 physisorption at 77 K, and the results of fitting the Kr and Xe adsorption isotherms with the Langmuir model. The BET surface area and micropore volume decrease monotonically (by 10 – 36 %) as the cation size increases (H+ < Li+ < Na+ < K+). The Langmuir constants (b) are not strongly influenced by ion exchange, indicating that the van der Waals interactions between the noble gas atoms and SAPO- 34 are not substantially affected by the cations. This is consistent with a previous report that lithium cation exchange does not notably change the heats of adsorption of CO2 and CH4 in SAPO-34 [9]. However, the Kr and Xe saturation capacities (qsat) decrease in the same order as the micropore volume, consistent with the decreased pore volume available as larger sizes and numbers of cations are introduced. Table 2. Gas adsorption and textural properties of SAPO-34 materials as obtained from Kr and Xe adsorption (298 K) and nitrogen physisorption (77 K) isotherms. H-SAPO-34 Li-SAPO-34 Na-SAPO-34 K-SAPO-34 BET surface area [m2/g] 480 429 323 306 Micropore volume [cm3/g] 0.23 0.21 0.20 0.18 qsat Kr 6.7 6.1 5.6 5.2 [mmol/g] Xe 5.2 4.8 4.4 4.1 b Kr 9.0 8.3 8.2 8.2 [10-4 kPa-1] Xe 39 37 36 39 The bulk compositions of the as-synthesized H-SAPO-34 and cation-exchanged M-SAPO- 34 (M = Li, Na, K) materials were determined using ICP-MS (H-SAPO-34 and Li-SAPO-34) and EDX analysis (H-SAPO-34, Na-SAPO-34, and K-SAPO-34) of the Si, P, and Al content.
Load more

Recommended publications
  • Tracer Applications of Noble Gas Radionuclides in the Geosciences
    To be published in Earth-Science Reviews Tracer Applications of Noble Gas Radionuclides in the Geosciences (August 20, 2013) Z.-T. Lua,b, P. Schlosserc,d, W.M. Smethie Jr.c, N.C. Sturchioe, T.P. Fischerf, B.M. Kennedyg, R. Purtscherth, J.P. Severinghausi, D.K. Solomonj, T. Tanhuak, R. Yokochie,l a Physics Division, Argonne National Laboratory, Argonne, Illinois, USA b Department of Physics and Enrico Fermi Institute, University of Chicago, Chicago, USA c Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA d Department of Earth and Environmental Sciences and Department of Earth and Environmental Engineering, Columbia University, New York, USA e Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL, USA f Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, USA g Center for Isotope Geochemistry, Lawrence Berkeley National Laboratory, Berkeley, USA h Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland i Scripps Institution of Oceanography, University of California, San Diego, USA j Department of Geology and Geophysics, University of Utah, Salt Lake City, USA k GEOMAR Helmholtz Center for Ocean Research Kiel, Marine Biogeochemistry, Kiel, Germany l Department of Geophysical Sciences, University of Chicago, Chicago, USA Abstract 81 85 39 Noble gas radionuclides, including Kr (t1/2 = 229,000 yr), Kr (t1/2 = 10.8 yr), and Ar (t1/2 = 269 yr), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, have enabled routine measurements of the radiokrypton isotopes, as well as the demonstration of the ability to measure 39Ar in environmental samples.
    [Show full text]
  • The Development of the Periodic Table and Its Consequences Citation: J
    Firenze University Press www.fupress.com/substantia The Development of the Periodic Table and its Consequences Citation: J. Emsley (2019) The Devel- opment of the Periodic Table and its Consequences. Substantia 3(2) Suppl. 5: 15-27. doi: 10.13128/Substantia-297 John Emsley Copyright: © 2019 J. Emsley. This is Alameda Lodge, 23a Alameda Road, Ampthill, MK45 2LA, UK an open access, peer-reviewed article E-mail: [email protected] published by Firenze University Press (http://www.fupress.com/substantia) and distributed under the terms of the Abstract. Chemistry is fortunate among the sciences in having an icon that is instant- Creative Commons Attribution License, ly recognisable around the world: the periodic table. The United Nations has deemed which permits unrestricted use, distri- 2019 to be the International Year of the Periodic Table, in commemoration of the 150th bution, and reproduction in any medi- anniversary of the first paper in which it appeared. That had been written by a Russian um, provided the original author and chemist, Dmitri Mendeleev, and was published in May 1869. Since then, there have source are credited. been many versions of the table, but one format has come to be the most widely used Data Availability Statement: All rel- and is to be seen everywhere. The route to this preferred form of the table makes an evant data are within the paper and its interesting story. Supporting Information files. Keywords. Periodic table, Mendeleev, Newlands, Deming, Seaborg. Competing Interests: The Author(s) declare(s) no conflict of interest. INTRODUCTION There are hundreds of periodic tables but the one that is widely repro- duced has the approval of the International Union of Pure and Applied Chemistry (IUPAC) and is shown in Fig.1.
    [Show full text]
  • Chemical Behavior of Iodine-131 During the SRE Fuel Element
    Chemical Behavior of Iodine- 13 1 during SRE Fuel Element Damage in July 1959 Response to Plaintiffs Expert Witness Arjun Makhijani by Jerry D. Christian, Ph.D. Prepared for in re Boeing Litigation May 26,2005 Background of Jerry D. Christian Education: B. S. Chemistry, University of Oregon, 1959. Ph. D. Physical Chemistry, University of Washington, 1965 - Specialty in Chemical Thermodynamics and Vaporization Processes of Halogen Salts. (Iodine is a halogen.) Postdoctoral: National Research Council Senior Research Associate, NASA Ames Research Center, Moffett Field, CAY1972-1974. Career Summary: Scientific Fellow, Retired from Idaho National Engineering and Environmental Laboratory (INEEL), September 2001. Scientific Fellow is highest achievable technical ladder position at INEEL; charter member, appointed in January 1987. Consultant and President of Electrode Specialties Company since retirement. Affiliate Professor of Chemistry, University of Idaho; I teach a course in nuclear fuel reprocessing. Referee for Nuclear Technology and Talanta journals; I review submitted technical manuscripts for the editors for scientific and technical validity and accuracy.* I have thirty nine years experience in nuclear waste and fuel processing research and development. Included in my achievements is development of the highly successful classified Fluorine1 Dissolution Process for advanced naval fuels that was implemented in a new $250 million facility at the ICPP in the mid-1980s. Career interests and accomplishments have been in the areas of nuclear
    [Show full text]
  • Of the Periodic Table
    of the Periodic Table teacher notes Give your students a visual introduction to the families of the periodic table! This product includes eight mini- posters, one for each of the element families on the main group of the periodic table: Alkali Metals, Alkaline Earth Metals, Boron/Aluminum Group (Icosagens), Carbon Group (Crystallogens), Nitrogen Group (Pnictogens), Oxygen Group (Chalcogens), Halogens, and Noble Gases. The mini-posters give overview information about the family as well as a visual of where on the periodic table the family is located and a diagram of an atom of that family highlighting the number of valence electrons. Also included is the student packet, which is broken into the eight families and asks for specific information that students will find on the mini-posters. The students are also directed to color each family with a specific color on the blank graphic organizer at the end of their packet and they go to the fantastic interactive table at www.periodictable.com to learn even more about the elements in each family. Furthermore, there is a section for students to conduct their own research on the element of hydrogen, which does not belong to a family. When I use this activity, I print two of each mini-poster in color (pages 8 through 15 of this file), laminate them, and lay them on a big table. I have students work in partners to read about each family, one at a time, and complete that section of the student packet (pages 16 through 21 of this file). When they finish, they bring the mini-poster back to the table for another group to use.
    [Show full text]
  • Isotopic Composition of Fission Gases in Lwr Fuel
    XA0056233 ISOTOPIC COMPOSITION OF FISSION GASES IN LWR FUEL T. JONSSON Studsvik Nuclear AB, Hot Cell Laboratory, Nykoping, Sweden Abstract Many fuel rods from power reactors and test reactors have been punctured during past years for determination of fission gas release. In many cases the released gas was also analysed by mass spectrometry. The isotopic composition shows systematic variations between different rods, which are much larger than the uncertainties in the analysis. This paper discusses some possibilities and problems with use of the isotopic composition to decide from which part of the fuel the gas was released. In high burnup fuel from thermal reactors loaded with uranium fuel a significant part of the fissions occur in plutonium isotopes. The ratio Xe/Kr generated in the fuel is strongly dependent on the fissioning species. In addition, the isotopic composition of Kr and Xe shows a well detectable difference between fissions in different fissile nuclides. 1. INTRODUCTION Most LWRs use low enriched uranium oxide as fuel. Thermal fissions in U-235 dominate during the earlier part of the irradiation. Due to the build-up of heavier actinides during the irradiation fissions in Pu-239 and Pu-241 increase in importance as the burnup of the fuel increases. The composition of the fission products varies with the composition of the fuel and the irradiation conditions. The isotopic composition of fission gases is often determined in connection with measurement of gases in the plenum of punctured fuel rods. It can be of interest to discuss how more information on the fuel behaviour can be obtained by use of information available from already performed determinations of gas compositions.
    [Show full text]
  • The Noble Gases
    INTERCHAPTER K The Noble Gases When an electric discharge is passed through a noble gas, light is emitted as electronically excited noble-gas atoms decay to lower energy levels. The tubes contain helium, neon, argon, krypton, and xenon. University Science Books, ©2011. All rights reserved. www.uscibooks.com Title General Chemistry - 4th ed Author McQuarrie/Gallogy Artist George Kelvin Figure # fig. K2 (965) Date 09/02/09 Check if revision Approved K. THE NOBLE GASES K1 2 0 Nitrogen and He Air P Mg(ClO ) NaOH 4 4 2 noble gases 4.002602 1s2 O removal H O removal CO removal 10 0 2 2 2 Ne Figure K.1 A schematic illustration of the removal of O2(g), H2O(g), and CO2(g) from air. First the oxygen is removed by allowing the air to pass over phosphorus, P (s) + 5 O (g) → P O (s). 20.1797 4 2 4 10 2s22p6 The residual air is passed through anhydrous magnesium perchlorate to remove the water vapor, Mg(ClO ) (s) + 6 H O(g) → Mg(ClO ) ∙6 H O(s), and then through sodium hydroxide to remove 18 0 4 2 2 4 2 2 the carbon dioxide, NaOH(s) + CO2(g) → NaHCO3(s). The gas that remains is primarily nitrogen Ar with about 1% noble gases. 39.948 3s23p6 36 0 The Group 18 elements—helium, K-1. The Noble Gases Were Kr neon, argon, krypton, xenon, and Not Discovered until 1893 83.798 radon—are called the noble gases 2 6 4s 4p and are noteworthy for their rela- In 1893, the English physicist Lord Rayleigh noticed 54 0 tive lack of chemical reactivity.
    [Show full text]
  • SAFETY DATA SHEET Nonflammable Gas Mixture: Fluorine / Krypton / Neon
    SAFETY DATA SHEET Nonflammable Gas Mixture: Fluorine / Krypton / Neon Section 1. Identification GHS product identifier : Nonflammable Gas Mixture: Fluorine / Krypton / Neon Other means of : Not available. identification Product type : Gas. Product use : Synthetic/Analytical chemistry. SDS # : 002503 Supplier's details : Airgas USA, LLC and its affiliates 259 North Radnor-Chester Road Suite 100 Radnor, PA 19087-5283 1-610-687-5253 24-hour telephone : 1-866-734-3438 Section 2. Hazards identification OSHA/HCS status : This material is considered hazardous by the OSHA Hazard Communication Standard (29 CFR 1910.1200). Classification of the : GASES UNDER PRESSURE - Compressed gas substance or mixture GHS label elements Hazard pictograms : Signal word : Warning Hazard statements : Contains gas under pressure; may explode if heated. May displace oxygen and cause rapid suffocation. Precautionary statements General : Read and follow all Safety Data Sheets (SDS’S) before use. Read label before use. Keep out of reach of children. If medical advice is needed, have product container or label at hand. Close valve after each use and when empty. Use equipment rated for cylinder pressure. Do not open valve until connected to equipment prepared for use. Use a back flow preventative device in the piping. Use only equipment of compatible materials of construction. Use only with equipment passivated before use. Use behind barricades with remote extensions on valves and regulators. Prevention : Not applicable. Response : Not applicable. Storage : Protect from sunlight. Store in a well-ventilated place. Disposal : Not applicable. Hazards not otherwise : In addition to any other important health or physical hazards, this product may displace classified oxygen and cause rapid suffocation.
    [Show full text]
  • Krypton-79M: a New Radionucide for Appications in Nuclear Medicine
    BASIC SCIENCES Krypton-79m: A New Radionucide for Appications in Nuclear Medicine William 0. Myers*t, J. Robert Dahl*, and Martin C. Graham* . Biophysics Laboratory, Memorial Sloan-Kettering Cancer Center, Sloan-Kettering Institute Division ofthe Graduate School ofMedical Sciences, Cornell University, New York, New York; tand Department ofRadiology, The Ohio State University, Columbus, Ohio Krypton-79memits 130-keV gamma rays in 27 ±1% of its disintegrations and decays with a half-life of 50 ±3 sec. It is generated readily by bombarding nearly saturated aqueous solutions of bromide salts, or bromoform, with 14-MeV protons. The 7@―Kris swept out continuously as it is produced by bubbling helium upward through the liquids. Up to 200 mCi per I are obtained of the resulting mixture of gases. The 7@―Kr+ helium is mixed with about fivevolumesof air andthendrivencontinuouslythrougha small-boretubeto an Anger scintillation camera located approximately 200 yards away. The rate of flow is adjusted so that the amountsof 13-sec8lmKrandof 35-hr @Krareinconsequentialat the timeandpoint of use. When the gases are inhaled, good images of the lungs are obtained with an Anger scintillation camera. The trachea and bronchi commonly are revealed also. J Nucl Med 27:1436—1441,1986 everal radionuclides of noble gases, which have The l30-keV gamma ray is nearly ideal for conven widely divergent physical properties, have been used in tional imaging techniques by means of an Anger scm nuclear medicine. These include: 35-hr krypton-79 tillation camera or similar dynamic nuclear medical (79Ki), 13-sec 8Im}(@.4.5-hr 85m}(@.,10.7-yr 85}(j.,36-day imaging instrument.
    [Show full text]
  • The Elements.Pdf
    A Periodic Table of the Elements at Los Alamos National Laboratory Los Alamos National Laboratory's Chemistry Division Presents Periodic Table of the Elements A Resource for Elementary, Middle School, and High School Students Click an element for more information: Group** Period 1 18 IA VIIIA 1A 8A 1 2 13 14 15 16 17 2 1 H IIA IIIA IVA VA VIAVIIA He 1.008 2A 3A 4A 5A 6A 7A 4.003 3 4 5 6 7 8 9 10 2 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.01 16.00 19.00 20.18 11 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 3 Na Mg IIIB IVB VB VIB VIIB ------- VIII IB IIB Al Si P S Cl Ar 22.99 24.31 3B 4B 5B 6B 7B ------- 1B 2B 26.98 28.09 30.97 32.07 35.45 39.95 ------- 8 ------- 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.47 58.69 63.55 65.39 69.72 72.59 74.92 78.96 79.90 83.80 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr NbMo Tc Ru Rh PdAgCd In Sn Sb Te I Xe 85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba La* Hf Ta W Re Os Ir Pt AuHg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 190.2 195.1 197.0 200.5 204.4 207.2 209.0 (210) (210) (222) 87 88 89 104 105 106 107 108 109 110 111 112 114 116 118 7 Fr Ra Ac~RfDb Sg Bh Hs Mt --- --- --- --- --- --- (223) (226) (227) (257) (260) (263) (262) (265) (266) () () () () () () http://pearl1.lanl.gov/periodic/ (1 of 3) [5/17/2001 4:06:20 PM] A Periodic Table of the Elements at Los Alamos National Laboratory 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Lanthanide Series* Ce Pr NdPmSm Eu Gd TbDyHo Er TmYbLu 140.1 140.9 144.2 (147) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Actinide Series~ Th Pa U Np Pu AmCmBk Cf Es FmMdNo Lr 232.0 (231) (238) (237) (242) (243) (247) (247) (249) (254) (253) (256) (254) (257) ** Groups are noted by 3 notation conventions.
    [Show full text]
  • Fact Sheet: What Is the Uranium Fuel Cycle? (PDF)
    What is the Uranium Fuel Cycle? Ofce of Radiation and Indoor Air (6608J) EPA 402-F-12-003 | September 2013 Milling of Reprocessing Uranium Ore Reprocessing is the initial Uranium is extracted separation of spent nuclear fuel Repository from ore with strong into its constituent parts. acids or bases. The Reprocessing is currently not uranium is concentrated taking place in the U.S. in a solid substance called “yellowcake.” Chemical Conversion Plants convert the uranium in yellowcake Spent Nuclear Fuel to uranium hexafuoride Used or “spent” nuclear (UF6), a compound fuel is stored in pools, or that can be made into in specially designed dry nuclear fuel. storage casks. Generation of Electricity at Nuclear Enrichment Power Plants Processing facilities Electricity is generated by concentrate uranium235-- nuclear power plants with the form (isotope) that is reactors that use water for capable of undergoing a moderating nuclear reactions nuclear reaction. and cooling. Fabrication of Fuel The enriched uranium is converted Dotted lines show EPAs’ “Environmental Radiation Protection Standards for processes that are into fuel pellets and placed into rods for use in nuclear power plants. Nuclear Power Operations” limit the radiation releases not currently taking and doses to the public from the normal operation of place in the U.S. uranium fuel facilities, including nuclear power plants. What is the Uranium Fuel Cycle? Environmental Radiation Protection Standards for Nuclear Power Operations Federal Register Reference—42 FR The Uranium Fuel Cycle: EPA and Nuclear 2860, Vol. 42, No. 9, January 13, 1977 Environmental Power Operations For more information, visit our website at: www.epa.gov/radiation/laws/190 Considerations EPA’s mission is to protect human health and the environment.
    [Show full text]
  • Infrared Emission Spectra of Krypton and Argon
    U. S. Department of Commerce Research Paper RP1790 National Bureau of Standards Volume 38, May 1947 Part of the Journal of Re search of the National Bureau of Standards Infrared Emission Spectra of Krypton and Argon By Curtis J. Humphreys and Earle K. Plyler The analysis of the spectra of the noble atmospheric gases, utilizing descriptive daLa covering the photographicall y accessible region, has long indicated the possibility of a con­ sid erable exte nsion of most of t hese spectra into the infrared region beyond 1.3 microns. Observations of the spectra of krypton a nd argo n, in the region be tween 1 and 2 mi crons, have been made with a Perkin-Elmer spec trometer, fi tted wi th a flin t-glass prism cut to an anglc of 55 degrees. Tlw sources " 'e re Ceis ler tubes, used in previously reported work. More than ] 5 new lineR of krypton have bee n obse rved. P art of these are blend s of unresolved pairs or groups. The emission maxima have been determined in favorable cases to a precision of two wave numbers, roughly equivalent to one- te nth of the small est scale division on the wavelength drum. All observed lines have been classifi ed, the most inte nse being represented by combinations of the type 2p- 3d, according to Paschen's notaLio n. Two new levels from the confi guration S2 p5J have been found. T he remaining unobserved com­ binations of the type l s- 2p, occurr ing in this region, arc, with one exception, too weak to be ob erved.
    [Show full text]
  • Major Uses of Radioisotopes
    Major Uses of Radioisotopes Used in many smoke detectors for homes and businesses… Americum-241 to measure levels of toxic lead in dried paint samples…to ensure uniform thickness in rolling processes like steel and paper production…and to help determine where oil wells should be drilled. Used to analyze metal alloys for checking stock, scrap sorting Cadmium-109 Important aid to biomedical researchers studying the Calcium-47 cellular functions and bone formation in mammals. Used to inspect airline luggage for hidden explosives…to Californium-252 gauge the moisture content of soil in the road construction and building industries…and to measure the moisture of materials stored in soils. Major research tool. Helps in research to ensure that Carbon-14 potential new drugs are metabolized without forming harmful by-products. Used in biological research, agriculture, pollution control, and archeology. Used to treat cancerous tumors…to measure correct patient Cesuim-137 dosages of radioactive pharmaceuticals…to measure and control the liquid flow in oil pipelines…to tell researchers whether oil wells are plugged by sand…and to ensure the right fill level for packages of food, drugs, and other products. (The products in these packages do not become radioactive.) Used in research in red blood cell survival studies. Chromium-51 Used as a tracer to diagnose pernicious anemia Cobalt-57 Used to sterilize surgical instruments…and to improve the Cobalt-60 safety and reliability of industrial fuel oil burners. Used in cancer treatment, food irradiation, gauges, and radiography. When injected with monoclonal antibodies into a cancer Copper-67 patient, helps the antibodies bind to and destroy the tumor.
    [Show full text]