DOCSLIB.ORG

Non-Natural Ruthenium Isotope Ratios of the Undeclared 2017

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Non-Natural Ruthenium Isotope Ratios of the Undeclared 2017 ARTICLE https://doi.org/10.1038/s41467-020-16316-3 OPEN Non-natural ruthenium isotope ratios of the undeclared 2017 atmospheric release consistent with civilian nuclear activities ✉ ✉ Timo Hopp 1,3,4, Dorian Zok2,4, Thorsten Kleine 1 & Georg Steinhauser 2 Understanding the circumstances of the undeclared 2017 nuclear release of ruthenium that led to widespread detections of the radioisotope 106Ru in the Eurasian region, and whether it 1234567890():,; derives from a civilian or military source, is of major importance for society and future improvements in nuclear safety. Until now, the released nuclear material has merely been studied by analyzing short-lived radioisotopes. Here, we report precise measurements of the stable isotopic composition of ruthenium captured in air filters before, during, and after the nuclear release, and find that the ruthenium collected during the period of the 2017 nuclear release has a non-natural isotopic composition. By comparing our results with ruthenium isotopic compositions of spent nuclear fuels, we show that the release is consistent with the isotopic fingerprints of a civilian Russian water-water energetic reactor (VVER) fuel at the end of its lifetime, and is not related to the production of plutonium for nuclear weapons. 1 Institut für Planetologie, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany. 2 Institute of Radioecology and Radiation Protection, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany. 3Present address: Origins Laboratory, Department of the Geophysical Sciences ✉ and Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637, USA. 4These authors contributed equally: Timo Hopp, Dorian Zok. email: thorsten. [email protected]; [email protected] NATURE COMMUNICATIONS | (2020) 11:2744 | https://doi.org/10.1038/s41467-020-16316-3 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | https://doi.org/10.1038/s41467-020-16316-3 nuclear accident may become a serious hazard for during the production of a highly radioactive 144Ce source humankind and exhibit long-lasting consequences for the commissioned for the European sterile neutrino project SOX- A 2,11 environment. Decades ago, and especially in the aftermath Borexino in the Gran Sasso National Laboratory (GSNL) . of the Chernobyl nuclear accident, global networks of monitoring The degree of burnup of the reprocessed fuel is key for stations were established for atmospheric radioactivity surveil- understanding the fuel’s past use prior to the release. High lance. They now have the sensitivity and precision to identify burnup would imply a civilian purpose of the spent fuel. Low atmospheric releases of even small amounts of anthropogenic burnup, by contrast, may indicate a military purpose, such as radionuclides1. In September and October 2017, these monitoring production of weapons-grade Pu or even utilization of low- stations detected a radioactive cloud over a wide swath of Europe burnup fissile material in a nuclear-powered missile17. With fi 106 = containing the ssion products Ru (T1/2 371.8 d) and traces increasing burnup, nuclear fuel will increasingly accumulate 103 2 240 of Ru (T1/2 = 39.2 d) . The characteristics of the release (e.g., Pu, which thwarts its applicability in nuclear warheads. lack of concomitant radionuclides) suggested that the source was Any use of low-burnup fuel would also affect the model age of a spent nuclear fuel reprocessing facility. The source term of the the released material. The above model age of 1.5–2 years after release was estimated at 250 TBq 106Ru, and atmospheric mod- neutron irradiation applies only to high-burnup fuel. In parti- eling indicated that the cloud originated in the southern Urals in cular, if low-burnup fuel had been used to produce the 144Ce the Russian Federation2,3. This area hosts one of the largest source above mentioned, the measured ratio of 103Ru/106Ru nuclear facilities in the world, the Federal State Unitary Enterprise would make the released material appear younger than its actual (FSUE) Production Association Mayak in Ozersk, Russia. age. In other words, low burnup could also mean that the fuel that Currently, no country has assumed responsibility for this was used for the 144Ce source was in fact “older” than the sug- considerable release, which is likely the single-largest accidental gested ≤2 years. This could mean that it underwent the estab- release from civilian nuclear reprocessing4. Despite a large lished and safe reprocessing scheme with ~3 years of cooling. As number of meteorological indications3,5–8, Russian authorities outlined in ref. 18, the compact design of the 144Ce source and institutions have repeatedly denied any involvement of the required exceptionally high specific activity, which is only Mayak facility in the release9–11. In their official statement9, the achievable either by reducing the minimum cooling time from 3 Rosatom State Nuclear Energy Corporation emphasized that to 2 years (high-burnup scenario) or by reprocessing fuel that has there were not any incidents at any of the Rosatom sites during undergone only approximately one-third of its nominal burnup the period of September–October 2017. The FSUE Production (i.e., prior to reaching the end of its lifetime), while allowing 3 Association Mayak is a subsidiary of Rosatom. The Russian years of cooling (low-burnup scenario). In any case, since Mayak authority also referred to this statement in response to a query not only hosts a reprocessing facility but also has an explicit concerning the release of 106Ru from the International Atomic military history, it has until now not been possible to rule out a Energy Agency (IAEA) to its 43 member states in the region12. military context or another low-burnup scenario of the release. According to IAEA, none of the countries reported an event that The circumstances of the incident cannot be assessed solely by could be the cause of the release of 106Ru in the fall of 201712.In analyzing the detected radioactive Ru isotopes, because the an interview with Nuclear Engineering International Magazine, resulting 103Ru/106Ru ratio is a function of neutron flux, energy the deputy director of the Nuclear Safety Institute of the Russian spectrum, fuel type that varies by reactor type and burnup, and Academy of Sciences (IBRAE) argued that “if the Mayak facility decay time. Since none of these variables are known, the 103Ru/ [were] the source, then we would have found concentrations 106Ru ratios do not allow the direct distinction of the provenance hundreds of thousands of times the norm around it and in the of the released material. The stable isotopic composition of soil10.” The IBRAE also set up an International Independent fission-generated Ru also depends on the fuel type, hence, varies Scientific Commission for the investigation of the release of by reactor type and burnup, but not on radioactive decay. 106Ru. The Commission gathered two times, in January and April Therefore, precise measurements of the stable isotopic composi- 201813,14. The Commission agreed on an estimated release source tion of fission-generated Ru can serve as an indicator of whether term of the event of ~100 TBq13. Science reported that a repre- the released material was produced in a civilian reactor or during sentative of the Russian nuclear regulator Rostechnadzor who a low-burnup scenario, e.g., the production of weapons-grade inspected Mayak in November 2017 told the Commission that he Pu19–21. saw no anomalies in the Mayak facility from a month earlier11. Here, we show that precise stable isotope analyses of Ru in Early alternative attempts at explanation of the release, such as a environmental samples can be used to constrain the provenance release on Romanian territory9 or the burning of a satellite’s of nuclear material released into the atmosphere. We present the radionuclide battery containing 106Ru10 had been addressed first high-precision measurements of stable Ru isotopic compo- previously2 and were essentially dispelled. While it is difficult to sitions of particulate matter collected in air filters including one imagine that a private facility could routinely handle such con- sample that contains material from the 2017 Ru release. We siderable activities, it is clear that nuclear facilities (both private conclude that the stable isotopic composition of the 2017 nuclear and state-run), including reprocessing facilities, must be operated release is consistent with fission-generated Ru produced in reg- under strict governmental regulatory control15 and report any ular, high-burnup spent fuel; hence, the nuclear release was most events to the regulator. likely related to an accident during reprocessing of spent fuel used Previous studies have focused on tracking the cloud across in civilian nuclear activities. Europe and have provided chemical insights, suggesting that the release occurred at an advanced stage of the reprocessing, when the Ru species had been transformed from initially produced Results Ruthenium isotopic compositions of air filter samples gaseous RuO4, at least in part, into one or more soluble com- . Isotopic pounds with medium volatility2. One of the released chemical anomalies caused by the decay of anthropogenic radioisotopes are species was identified as a polychlorinated Ru(III) form16. The extremely difficult to observe in regular environmental samples as release carried a 103Ru/106Ru signature of very young spent fuel the additional input of the decay products
Load more

Recommended publications
  • The Discoverers of the Ruthenium Isotopes
    •Platinum Metals Rev., 2011, 55, (4), 251–262• The Discoverers of the Ruthenium Isotopes Updated information on the discoveries of the six platinum group metals to 2010 http://dx.doi.org/10.1595/147106711X592448 http://www.platinummetalsreview.com/ By John W. Arblaster This review looks at the discovery and the discoverers Wombourne, West Midlands, UK of the thirty-eight known ruthenium isotopes with mass numbers from 87 to 124 found between 1931 and 2010. Email: [email protected] This is the sixth and fi nal review on the circumstances surrounding the discoveries of the isotopes of the six platinum group elements. The fi rst review on platinum isotopes was published in this Journal in October 2000 (1), the second on iridium isotopes in October 2003 (2), the third on osmium isotopes in October 2004 (3), the fourth on palladium isotopes in April 2006 (4) and the fi fth on rhodium isotopes in April 2011 (5). An update on the new isotopes of palladium, osmium, iridium and platinum discovered since the previous reviews in this series is also included. Naturally Occurring Ruthenium Of the thirty-eight known isotopes of ruthenium, seven occur naturally with the authorised isotopic abun- dances (6) shown in Table I. The isotopes were fi rst detected in 1931 by Aston (7, 8) using a mass spectrograph at the Cavendish Laboratory, Cambridge University, UK. Because of diffi cult experimental conditions due to the use of poor quality samples, Aston actually only detected six of the isotopes and obtained very approximate Table I The Naturally Occurring Isotopes of Ruthenium Mass number Isotopic Abundance, % 96Ru 5.54 98Ru 1.87 99Ru 12.76 100Ru 12.60 101Ru 17.06 102Ru 31.55 104Ru 18.62 251 © 2011 Johnson Matthey http://dx.doi.org/10.1595/147106711X592448 •Platinum Metals Rev., 2011, 55, (4)• percentage abundances.
    [Show full text]
  • Properties and Applications of Ruthenium
    Chapter 17 Properties and Applications of Ruthenium Anil K. Sahu, Deepak K. Dash, Koushlesh Mishra, Saraswati P. Mishra, Rajni Yadav and Pankaj Kashyap Additional information is available at the end of the chapter http://dx.doi.org/10.5772/intechopen.76393 Abstract Ruthenium (Ru) with atomic number of 44 is one of the platinum group metals, the others being Rh, Pd, Os, Ir and Pt. In earth’s crust, it is quite rare, found in parts per billion quantities, in ores containing some of the other platinum group metals. Ruthenium is silvery whitish, lustrous hard metal with a shiny surface. It has seven stable isotopes. Recently, coordination and organometallic chemistry of Ru has shown remarkable growth. In this chapter, we review the application of Ru in diverse fields along with its physical and chemical properties. In the applications part of Ru we have primarily focused on the biomedical applications. The biomedical applications are broadly divided into diagnostic and treatment aspects. Ru and their complexes are mainly used in determination of ferritin, calcitonin and cyclosporine and folate level in human body for diagnosis of diseases. Treat- ment aspects focuses on immunosuppressant, antimicrobial and anticancer activity. Keywords: ruthenium, platinum group, biomedical application, rare element, cancer, isotopes 1. Discovery of ruthenium Ruthenium is one of the 118 chemical elements given in the periodic table. Out of these 118 elements, 92 elements originated from natural sources and remaining 26 elements have been synthesized in laboratories [1, 2]. The last naturally occurring element to be discovered was Uranium in 1789 [1, 3]. Technetium was the first man-made element to be synthesized in the year 1937 [2].
    [Show full text]
  • Activation Cross Sections of Proton Induced Nuclear Reactions on Palladium up to 80 Mev
    Activation cross sections of proton induced nuclear reactions on palladium up to 80 MeV F. Tark´ anyi´ a, F. Ditroi´ a,∗, S. Takacs´ a, J. Csikaia, A. Hermanneb, S. Uddind, M. Babad aInstitute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary bCyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels, Belgium cInstitute of Physics and Power Engineering (IPPE), Obninsk, Russia dCyclotron Radioisotope Center (CYRIC), Tohoku University, Sendai, Japan Abstract Activation cross sections of proton induced nuclear reactions on palladium were measured up to 80 MeV by using the stacked foil irradiation technique and gamma ray spectrometry. The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the excitation functions of monitor reactions measured in parallel. Excitation functions for direct and cumulative cross-sections were measured for the production of 104m;104g;105g;106m;110mAg, 100;101Pd, 99m;99g;100;101m;101g;102m;102g;105Rh and 103;97Ru radioisotopes. The cross section data were compared with the theoretical predictions of TENDL-2014 and -2015 libraries. For practical applications thick target yields were derived from the measured excitation functions. Application in the field of medical radionuclide production is shortly discussed. Keywords: proton irradiation, palladium target, stacked foil technique, cross sections, production yields 1. Introduction Hu et al., 1998; Johnson et al., 1979; Kormali et al., 1976; Zarubin and Sergeev, 1989). Our results obtained Excitation functions of proton induced nuclear re- in that period for some medically relevant radionuclides actions on palladium are important in many applica- were published during 2004-2007.
    [Show full text]
  • RUTHENIUM Element Symbol: Ru Atomic Number: 44
    RUTHENIUM Element Symbol: Ru Atomic Number: 44 An initiative of IYC 2011 brought to you by the RACI NICKI BURNS www.raci.org.au RUTHENIUM Element symbol: Ru Atomic number: 44 The element ruthenium is named after Ruthenia. This word is a Latin rendering of the historical territory of Rus, which today is formed with parts of Belarus, Ukraine, western Russia,northeastern Slovakia and eastern Poland. Ruthenium was discovered in 1844 by Karl Karlovitch Klaus, then an unknown professor at the University of Kazan. Klaus could be considered the creator of the chemistry of the platinum metals because of his extensive investigation of rhodium, iridium, osmium, and to a lesser extent, palladium and platinum. Ruthenium is the 74th most abundant metal on Earth and is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America. Roughly 12 tonnes of ruthenium is mined each year. Ruthenium is also a fission product of235 Uranium, however the extraction from used nuclear fuel is complicated, expensive and also results in radioactive isotopes of ruthenium. Ruthenium has several applications. An alloy containing small amounts of ruthenium with gold increases the stability of gold in jewellery. It is also used in some advanced high-temperature single-crystal superalloys with applications including the turbine blades in jet engines. The “RU” nib in the famous Parker 51 fountain pen was a 14K gold nib tipped with 96.2% ruthenium and 3.8% iridium. 106Ruthenium, a β-decaying isotope, is used in radiotherapy of eye tumours, mainly malignant melanomas of the uvea.
    [Show full text]
  • The Preparation and Characterization of Some Alkanethiolatoosmium Compounds Harold Harris Schobert Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1970 The preparation and characterization of some alkanethiolatoosmium compounds Harold Harris Schobert Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Inorganic Chemistry Commons Recommended Citation Schobert, Harold Harris, "The preparation and characterization of some alkanethiolatoosmium compounds " (1970). Retrospective Theses and Dissertations. 4357. https://lib.dr.iastate.edu/rtd/4357 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. 71-14,258 SCHOBERT, Harold Harris, 1943- THE PREPARATION AND CHARACTERIZATION OF SOME ALKANETHIOLATOOSMIUM COMPOUNDS. Iowa State University, Ph.D., 1970 Chemistry, inorganic University Microfilms, A XEROX Company, Ann Arbor, Michigan THIS DISSERTATION HAS BEEH MICROFILMED EXACTLY AS RECEIVED THE PREPARATION AND CHARACTERIZATION OF SOME ALKANETHIOLATOOSMIUM COMPOUNDS by Harold Harris Schobert A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Inorganic Chemistry Approved: Signature was redacted for privacy. Signature was redacted for
    [Show full text]
  • INGESTION PATHWAY the Emergency Planning Zone (EPZ) for the Ingestion Pathway Extends to a Radius of 50 Miles Through 360 Degrees from a Nuclear Power Plant
    WV REP Plan Issue 9, Revision 0 (11-Jan.-19) Annex 15a. – Accident Assessment (Post-Plume Phase) INGESTION PATHWAY The Emergency Planning Zone (EPZ) for the ingestion pathway extends to a radius of 50 miles through 360 degrees from a nuclear power plant. Major potential pathways for ingestion include fresh fluid milk and other food commodities (especially those consumed fresh, such as leafy vegetables and fruit), and public water supply systems using surface water. This section summarizes the protective action guidance and appropriate protective actions for each major ingestion pathway. Criteria are established for initiation of ingestion protective actions. Dose commitment resulting from the ingestion pathway is separate and distinct from doses received in other incident phases. MILK AND FOOD MILK AND FOOD PROTECTIVE ACTION GUIDES (PAGs) The PAGs used for milk and food were developed by HHS/FDA, and published as Accidental Radioactive Contamination of Human Food and Animal Feeds: Recommendations for State and Local Agencies by FDA on August 13, 1998 (FDA 1998). These values are intended to include both the milk and food components of the diet and represent the dose commitment from ingestion over the entire episode. Calculation of projected dose commitment from the ingestion pathway is described in Attachment 1, “Ingestion Pathway Dose Projections Procedure”. FDA guidance is described below. Ingestion Protective Action Guides (PAGs) A Protective Action Guide (PAG) is the committed effective dose equivalent (CEDE) or committed dose equivalent (CDE) to an individual tissue or organ that warrants protective action following a release of radionuclides. Annex 15a – Accident Assessment (Post-Plume Phase) 15a-1 WV REP Plan Issue 9, Revision 0 (11-Jan-19) The Ingestion Pathway PAGs are: 0.5 rem (5 mSv) committed effective dose equivalent (CEDE), -or- 5.0 rem (50 mSv) committed dose equivalent (CDE) to an individual tissue or organ, whichever is most limiting.
    [Show full text]
  • Prospects for Baryon Instability Search with Long-Lived Isotopes
    Submitted to the Proceedings of International Workshop on Future Prospects of Baryon Instability Search in p-decay and n -» n oscillation experiments, Oak Ridge, TN, March 28-30,1996 PROSPECTS FOR BARYON INSTABILITY SEARCH WITH LONG-LIVED ISOTOPES Yu. Efremenkoab, W. Buggb, H. Cohnb, Yu. Kamyshkov*11, G. Parker4, F. Plasila * Oak Ridge National Laboratory, Oak Ridge, TN 37831 b University of Tennessee, Knoxville, TN 37996 h-f -£j ABSTRACT BEC 1 $ In this paper we consider the possibility of observation of baryon instability r \ o -v> • processes occurring inside nuclei by searching for the remnants of such processes that *-' Ox"§- .J could have been accumulated in nature as rare long-lived isotopes. As an example, we discuss here the possible detection of traces of 97Tc, 98Tc, and "Tc in deep-mined non- radioactive tin ores. Introduction The possible experimental observation of baryon instability remains among the most fundamental problems of modern physics [1]. The observed "baryon asymmetry" of the Universe [2] and some Unification Theories including Supersymmetric Models [3,4,5] require either nucleon-decay (with baryon number change by AB=1) or neutron- antineutron transitions (with baryon number change by AB=2) with rates stretching the limits of present experimental capabilities. Future prospects for proton decay and neutron- antineutron transition searches by traditional detection techniques have been reviewed in a number of contributions to this Workshop [1,6,7,8,9]. These techniques are based, in general, on the direct detection in real time of the final products of baryon transformation leading to the disappearance of one or two nucleons inside the nuclei corresponding to A B=l and AB=2, respectively.
    [Show full text]
  • The Fukushima Daiichi Accident Technical Volume 4
    The Fukushima Daiichi Accident Fukushima The The Fukushima Daiichi Accident Technical Volume 4/5 Technical Volume 4/5 Radiological Consequences Radiological Consequences Radiological PO Box 100, Vienna International Centre 1400 Vienna, Austria Printed in Austria ISBN 978–92–0–107015–9 (set) 1 THE FUKUSHIMA DAIICHI ACCIDENT TECHNICAL VOLUME 4 RADIOLOGICAL CONSEQUENCES The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GERMANY OMAN ALBANIA GHANA PAKISTAN ALGERIA GREECE PALAU ANGOLA GUATEMALA PANAMA ARGENTINA GUYANA PAPUA NEW GUINEA ARMENIA HAITI PARAGUAY AUSTRALIA HOLY SEE PERU AUSTRIA HONDURAS PHILIPPINES AZERBAIJAN HUNGARY POLAND BAHAMAS ICELAND PORTUGAL BAHRAIN INDIA QATAR BANGLADESH INDONESIA REPUBLIC OF MOLDOVA BELARUS IRAN, ISLAMIC REPUBLIC OF ROMANIA BELGIUM IRAQ RUSSIAN FEDERATION BELIZE IRELAND RWANDA BENIN ISRAEL SAN MARINO BOLIVIA, PLURINATIONAL ITALY SAUDI ARABIA STATE OF JAMAICA SENEGAL BOSNIA AND HERZEGOVINA JAPAN SERBIA BOTSWANA JORDAN SEYCHELLES BRAZIL KAZAKHSTAN SIERRA LEONE BRUNEI DARUSSALAM KENYA SINGAPORE BULGARIA KOREA, REPUBLIC OF SLOVAKIA BURKINA FASO KUWAIT SLOVENIA BURUNDI KYRGYZSTAN SOUTH AFRICA CAMBODIA LAO PEOPLE’S DEMOCRATIC SPAIN CAMEROON REPUBLIC SRI LANKA CANADA LATVIA SUDAN CENTRAL AFRICAN LEBANON SWAZILAND REPUBLIC LESOTHO SWEDEN CHAD LIBERIA SWITZERLAND CHILE LIBYA SYRIAN ARAB REPUBLIC CHINA LIECHTENSTEIN TAJIKISTAN COLOMBIA LITHUANIA CONGO LUXEMBOURG THAILAND COSTA RICA MADAGASCAR THE FORMER YUGOSLAV CÔTE D’IVOIRE MALAWI REPUBLIC OF MACEDONIA CROATIA MALAYSIA TOGO
    [Show full text]
  • Co-Production of Light and Heavy $ R $-Process Elements Via Fission
    Draft version June 22, 2020 Typeset using LATEX twocolumn style in AASTeX62 Co-production of Light and Heavy r-process Elements via Fission Deposition Nicole Vassh,1 Matthew R. Mumpower,2, 3 Gail C. McLaughlin,4 Trevor M. Sprouse,5 and Rebecca Surman5, 3 1University of Notre Dame, Notre Dame, IN 46556, USA 2Theoretical Division, Los Alamos National Lab, Los Alamos, NM 87545, USA 3Joint Institute for Nuclear Astrophysics - Center for the Evolution of the Elements, USA 4North Carolina State University, Raleigh, NC 27695, USA 5University of Notre Dame, Notre Dame, Indiana 46556, USA ABSTRACT We apply for the first time fission yields determined across the chart of nuclides from the macroscopic- microscopic theory of the Finite Range Liquid Drop Model to simulations of rapid neutron capture (r-process) nucleosynthesis. With the fission rates and yields derived within the same theoretical framework utilized for other relevant nuclear data, our results represent an important step toward self- consistent applications of macroscopic-microscopic models in r-process calculations. The yields from this model are wide for nuclei with extreme neutron excess. We show that these wide distributions of neutron-rich nuclei, and particularly the asymmetric yields for key species that fission at late times in the r process, can contribute significantly to the abundances of the lighter heavy elements, specifically the light precious metals palladium and silver. Since these asymmetric yields correspondingly also deposit into the lanthanide region, we consider the possible evidence for co-production by comparing our nucleosynthesis results directly with the trends in the elemental ratios of metal-poor stars rich in r-process material.
    [Show full text]
  • Reconstruction Behaviors of of Cumulative Fission Fissiogenic
    Geochemical Journal, Vol. 26, pp. 227 to 239, 1992 Reconstruction of cumulative fission yield curve and geochemical behaviors of fissiogenic nuclides in the Oklo natural reactors HIROSHI HIDAKA*, TAKASHI KONISHI and AKIMASA MASUDA Department of Chemistry, The University of Tokyo, Tokyo 113, Japan (Received November 25, 1991; Accepted July 20, 1992) Isotopic ratios and elemental abundances of rare earth elements (REE), Rb, Sr, Zr, Mo, Ru, Pd, Ag, Te, Ba and U in four samples from two Oklo Reactor Zones 7, 8, 9 and 10 were determined by ther mal ionization mass spectrometry. These elements have unusual but reasonable isotopic anomalies due to the effect of fission and/or neutron capture reactions. In order to discuss the retentivity of fissiogenic nuclides, the fission product yield curves covering the wide mass range from 90 to 160 were reconstructed on the basis of our results. We have estimated the behavior of fissiogenic nuclides by means of the differences between the measured curves and empirical ones. From comparison of these two sets of curves, measured and empirical, the behaviors of fissiogenic nuclides were deduced. Our results are in agreement with previous Oklo work at the following points: (I) Ru, Pd, Te and most of a series of REE (except for La and/or Ce) have been well retained in the samples, (II) Rb, Sr and Ba have been lost to a great extent, and their isotopic ratios are nearly the same as those of terrestrial standard values, and (III) Zr, Mo and Ag have been partially removed from the reactors. The behaviors of Zr and Mo seem to have been highly affected by the chemical and geological environments in and around the reac tors.
    [Show full text]
  • Nov. 12, 1974 3,848,048
    Nov. 12, 1974 R. H. MOORE 3,848,048 RECOVERY OF FISSION-PRODUCED TECHNETIUM, PALLADIUM, RHODIUM AND RUTHENIUM Filed July 12. 1973 cr, in "O EZ CLE 3 a. J I £T "O LLS GL O -J < Q United States Patent Office P„lented 2 3,848,048 Technetium and the platinum group metals, ruthenium, RECOVERY OF FISSION-PRODUCED TECH- rhodium and palladium, are produced in fairly high yield NETIUM, PALLADIUM, RHODIUM AND in nuclear reactors. Technetium is nonexistent in nature RUTHENIUM and may have properties of value which warrant its re- Raymond H. Moore, Richland, Wash., assignor to the 5 covery. The platinum metals are of high intrinsic value United States of America as represented by the United and should be recovered to supplement waning natural States Atomic Energy Commission resources. Filed July 12,1973, Ser. No. 378,471 The projected annual availability of technetinm and the Int. CI. COlg 55/00, 57/00 platinum group metals is given in Table I below: i U.S. CI. 423—22 5 Claims 10 TABLE I Annual Availability of Fission Product Pd, Eh, Ru and Te In (10') ABSTRACT OF THE DISCLOSURE Troy oz./yr." The fission-produced technetium and the platinum Pd Eh Eu To metals, palladium, rhodium and ruthenium, are recovered ic 1970 0.77 0.51 2.3 0.93 from an aqueous acidic fuel reprocessing waste solution 1975 _ 22-23 1S-14 61-67 25-27 1980- ... 55-75 30^12 145-201 57-70 and separated from each other by contacting the waste 1985. 115-170 6<t-95 302-450 119-178 solution sequentially with a series of beds of carbon, each 1990 214-328 110-176 524-801 201-311 bed having adsorbed thereon a different chelating agent a The ranges given reflect the differences obtained from the difieren specific for the metals to be recovered, whereby the metal types of reactors.
    [Show full text]
  • Contamination with Ruthenium 106 Results of Soil Tests Carried out by the CRIIRAD Laboratory in the Environment of the Mayak Nuclear Site
    CRIIRAD report N°18-21 Valence, February 16th 2018 Ru-106 / Mayak Commission de Recherche et d’Information Indépendantes sur la Radioactivité 29 cours Manuel de Falla / 26000 Valence / France . 33 (0)4 75 41 82 50 / [email protected] Contamination with ruthenium 106 Results of soil tests carried out by the CRIIRAD laboratory in the environment of the Mayak nuclear site Editor: Bruno CHAREYRON, nuclear physics engineer, director of the CRIIRAD laboratory. Contact : [email protected] 1 / Context: need to document the "Mayak" hypothesis Following the detection of ruthenium 106 in the air of about 30 countries from late September to mid- October 2017, the origin of the source is still debated. Among the many assumptions, that of an "incident" on the nuclear site "Mayak" was considered by CRIIRAD in October1 and remains one of the strongest. This nuclear site is located in Russia, in the sector pointed by the modelizations of several institutes (even if it is not located in the most probable zone resulting from modelizations published on November 9th by the French IRSN and November2 10th by Ukrainian scientists). Given the extent of atmospheric contamination, the release of ruthenium 106 was necessarily very high. In its communication3 of November 9th, 2017, the IRSN for its part gave an estimate of 100 to 300 TBq or 100 000 to 300 000 billions becquerels. It is unlikely that such a large release will come from a facility designed to produce ruthenium 106 for medical purposes. The Mayak site is engaged in the reprocessing of spent fuel and the vitrification of highly radioactive waste, which leads to the regular release4 of ruthenium 106 to the atmosphere (2.23 billion becquerels of Ru-Rh106 in 2015 according to the annual report of the Mayak site).
    [Show full text]