DOCSLIB.ORG

An Analysis of Misconceptions About Thorium-Based Fuel Cycles As a Technical Fix to the Nuclear Proliferation Problem

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
An Analysis of Misconceptions About Thorium-Based Fuel Cycles As a Technical Fix to the Nuclear Proliferation Problem An analysis of misconceptions about thorium-based fuel cycles as a technical fix to the nuclear proliferation problem. This paper analyzes several pre- rich to bomb-usable levels than natu- of the plutonium economy are taken valent misconceptions about nuclear ral uranium. Such enrichment can be as read. Nothing in this article fuel cycles that breed fissile done at a modest scale with readily should be construed to imply that: uranium-233 from thorium. Its main available centrifuges. L e the proliferation risks of conclusions are: a Several other features of mixed plutonium fuel cycles can be made a Uranium-233, despite the thorium-uranium cycles are rather tolerable, or gamma radioactivity of associated unattractive from a safeguards point 9 any commitment (even an ex- isotopes, is a rather attractive mate- of view. ploratory one) to a plutonium econ- rial for making fission bombs, and is Thus thorium cycles of any kind omy need be made for many de- a credible material for subnational as cades, perhaps even a century or two, well as national groups to use for this are not a technical fix for prolifera- tion (national or subnational) and, any improvement in existing purpose. safeguards (such as those sought by e "Pure" thorium cycles, which in though probably more safeguardable than plutonium cycles, are less so the Carter administration1 is not effect merely substitute uranium-233 worth making only because it does for plutonium, would take many than once-through uranium cycles that entail no reprocessing. not solve the whole problem, or decades and much uranium to any form of nuclear power is a While thorium cycles have some establish, and offer no significant necessary or desirable. safeguards advantage over plu- potential technical advantages, in- cluding flexibility, they cannot pro- All these fallacies are addressed tonium cycles. elsewhere [2]. While some of my ar- vide major savings in nuclear fuel re- e "Denatured" thorium-uranium guments have been previously ad- cycles, which dilute the uranium-233 sources compared to simpler ways of saving neutrons and uranium. vanced by advocates of plutonium with inert uranium-238 to a level not fuel cycles, presumably seeking to directly usable in bombs, are not an Thus while advocates of nuclear suggest that their option is accept- effective safeguard even against power may find thorium cycles able because the thorium alternative subnational bomb-making. This is worth exploring, such cycles do not to it is nearly as bad, I shall suggest because three factors-higher initial differ fundamentally from uranium that neither is acceptable. Thus any fissile content, larger mass dif- cycles in any of the respects- out-of-context quotation of this ference between isotopes, and including safeguards and fuel paper in support of plutonium cycles smaller amount of material needed resources-that are relevant to the would be perverse and misleading. for a bomb-make such "de- broader nuclear debate, and should Since proposals were widely pub- natured" uranium-233/238 fuel one not be euphorically embraced as if lished in 1976-1977, notably by or two hundred times easier to en- they did.-A.B.L. Taylor and Feiveson 131, for a "de- natured" [4] thorium cycle which If nuclear fission is to be used as an FO~~-MITREreports. Those who be- might be less proliferative (espe- energy source, whether it should use lieve plutonium is nasty and uranium cially to subnational groups) than a fuel cycles that require plutonium to may be scarce call attention to fuel- plutonium-uranium fuel cycle [5], be extracted and re-used turns on efficient, non-plutonium fuel cycles. some people [6] have jumped to the two independent questions [I]. The It is this last, perhaps most interest- conclusion that thorium cycles in first is whether plutonium is bearable ing, group that has recently recalled general and denatured thorium cy- and the second is whether a lot of attention to thorium-based fuel cy- cles in particular offer a technical fix uranium is available (geologically cles which appear to many nuclear to the proliferation problem. This is and politically) at relatively low advocates to merit study on several incorrect. It is also certainly not prices. Few if any analysts answer grounds, potentially greater resist- what such authors as Taylor, Feive- yes to both questions; and for any ance to the proliferation of nuclear son, Cochran, and von Hippel had in who do, policy choices are un- weapons being high among them. mind: they proposed denatured constrained. Those who believe It is this cluster of proposals, and thorium only as proof of the exis- plutonium is bearable and uranium some prevalent misinterpretations of tence of fuel cycles which might, on scarce build fast breeder reactors. them (especially common in Britain closer study, prove to be inherently Those who believe plutonium is and Canada), that this article briefly less proliferative than uranium/ nasty and uranium plentiful write discusses. The arguments of critics plutonium cycles. Since at least one The concern over weapons proliferation problems has lately led to serious international consideration of alternative nuclear fuel cycles. Among these. cycles involving the breeding of the uranium-233 isotope from thorium, especially with provisions for its "denaturing" with ordinary uranium, are generally believed to show great promise for a nuclear energy future without weapons proliferation. In this article the author dashes cold water on the most optimistic of such expectations.-Ed . such fuel cycle could be envisaged, 15.8 grams per cubic centimeter). ting use of a gun-type rather than an they argued, it is important not to (Corresponding figures for the alpha implosive assembly-a further op- rush ahead with a plutonium eco- phase of plutonium, at around 19.8 tion which may be easier than an im- nomy before potentially less pro- grams per cubic centimeter, are 11 plosive design. Both chemically and liferative options are carefully kilograms for nearly pure metallurgically ui'anium-233 is con- examined. plutonium-239 and 13 kilograms for siderably more tractable than The early stages of that closer "reactor-grade" plutonium pro- plutonium: it is not very pyrophoric examination have made it clear that duced at a burnup around 30 thermal and has one solid phase, not six. Its thorium fuel cycles, including de- gigawatt days per metric ton of inhalation toxicity is considered to natured ones, do not qualitatively uranium. Of course all these quan- be about 70 times lower than that of alter the prolifefation problem tities can be reduced greatly-more plutonium-239, several hundred (either national or sbbnational) and than fivefold-by reflection and im- times lower than that of reactor- in some respects offer more avenues plosion in a nuclear explosive.) grade plutonium. for proliferation than once-through Broadly speaking [7],for fast neut- The only significant disadvantage uranium cycles. The reactor-physics rons the relative neutron yield is of uranium-233 is that after produc- and safeguards considerations sup- tion, various daughters of uranium- porting this conclusion are some- 232 build up in it (peaking about 10 what elementary, but the scarcity of years after extraction), notably systematic analyses of them has and the fission cross-section thallium-208. Some uranium-232 lately generated much misplaced en- daughters emit intense and penetrat- thusiasm [6]: hence this summary, ing gamma rays, of which thallium- These conclusions are relatively in- 208 typically contributes more than Thorium and Uranium-233. There sensitive to contamination of the half the total with its 2.6- and 0.6- are two basic kinds of thorium cy- uranium-233 with traces of other megavolt emissions. Commercial cles, both of which may breed fissile uranium isotopes. handling of uranium-233, especially uranium-233 from fertile thorium- Because uranium-233 is about if it were more than a few days old 232, mainly via the intermediate three times as reactive as uranium- (whereas aging for about a year is product protactinium-233, which has 235 (whose bare-sphere critical mass desirable for full decay of the a 27-day half-life. The first kind is the at 93.5 percent enrichment is about protactinium-233 arent of the "pure" thorium cycle, a self- 50 kilograms), one might expect that uranium-2331, woul 1require heavy sustaining one relying on previously a third as much of it would be re- shielding-of order twice as much as bred uranium-233 for fission neut- quired for a bomb. In fact the re- the gamma- and neutron-emitting re- rons to breed more uranium-233 in ciprocal of this ratio, the "substitu- cycle plutonium requires-to protect fuel consisting of uranium-233 mixed tion factor," is not 3 but typically 5 workers from overexposure. But if with thorium-232. Burnup of this fuel to 10 because a physically smaller relatively small amounts of produces various isotopes, up to and core can be compressed more in a uranium-233 were being dealt with including small amounts of convergent implosion. (An in- for relatively short periods outside plutonium formed by successive compressible solid spherical shell, if the restrictions of prudent health- neutron captures. imploded, provides a pressure vary- physics practice, shielding could be From a weapons physics point of ing as the inverse fourth power of its greatly reduced or even dispensed view, uranium-233 is similar and in radius @I.) with. some respects perhaps superior to Ordinarily uranium-233 has a sub- A kilogram of uranium-233 pro- plutonium-239, the classical mate- stantial neutron background because duced at 46 thermal gigawatt days per rial. They are roughly equal in re- of (a,n) reactions with light-element metric ton of heavy metal burnup activity, as shown by the nearly impurities.
Load more

Recommended publications
  • Th Thorium Compounds with S, Se, Te and B
    springer.com Chemistry : Chemistry (general) Brown, David, Wedemeyer, Horst, Buschbeck, Karl-Christian, Keller, Cornelius (Editors-in-chief.) Th Thorium Compounds with S, Se, Te and B The present volume, Thorium C5, deals with the compounds of thorium and sulfur, selenium, tellurium, and boron, as well as with oxoacid compounds of the three chalcogen elements. Thorium borates have already been treated in Thorium C2. In contrast to the corresponding compounds of uranium the thorium sulfides, etc. , do not show any nuclear or other technological application; they are only of academic interest, despite some very interest• ing electronic properties, especially of the 1 : 1 compounds. The thorium-sulfur and the thorium• boron systems in particular were studied in detail, so that we have a clear picture of them, whereas there are still a lot of open questions in the systems Th-Se and Th-Te - not very different from other metal chalcogenide systems. Thorium sulfates are of some technological importance because they are formed in solution during recovery of thorium from monazite by sulfuric acid leaching. The very detailed and critical treatment of the chemical and physical Springer properties of the compounds discussed also enables us to find gaps still remaining in our 8th ed. 1985, XIX, 149 p. knowledge and thus to initiate new research in this field. I want to thank the two authors, Dr. 8th 28 illus., 1 illus. in color. edition Horst Wedemeyer (Karlsruhe) and Dr. David Brown (Harwell), for their excellent contributions, the "Literaturabteilung" of the Karlsruhe Nuclear Research Center for its help in providing reports and other documents difficult to procure, as well as the staff of the Gmelin-Institute, especially to Dr.
    [Show full text]
  • Study of Rare Earth Elements, Uranium and Thorium Migration in Rocks from Espinharas Uranium Deposit, Paraiba - Brazil
    2009 International Nuclear Atlantic Conference - INAC 2009 Rio de Janeiro,RJ, Brazil, September27 to October 2, 2009 ASSOCIAÇÃO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-03-8 STUDY OF RARE EARTH ELEMENTS, URANIUM AND THORIUM MIGRATION IN ROCKS FROM ESPINHARAS URANIUM DEPOSIT, PARAIBA - BRAZIL Cirilo C.S. Conceição Instituto de Radioproteção e Dosimetria -IRD Av. salvador Allend, S/N - Jacarepaguá Rio de Janeiro, Brazil CEP.: 22780-160 [email protected] ABSTRACT The determination of Rare Earth Elements as natural analogue in patterns geologic has grown as a tool for predicting the long-term safety of nuclear disposal in geological formation. Migration of natural radionuclides is one of the most serious problems in the waste deposit from nuclear fuel cycle. Rare Earth Elements show the same kinetic behavior in rocks as natural radionuclides. This similar property of the analogues allows perform studies and models on the subject of radionuclides migration. The aim of this study was to determine the distribution of Rare Earth Elements in rocks located at Espinharas – Paraíba – Brazil, uranium deposit. In this work are presented the results from the study above the distribution of rare earth elements in function of the degree of mineralized rocks, composition and the conditions of radioactive equilibrium of the uranium and thorium in some fractures on the rocks from radioactive occurrence of Espinharas-Brazil. The results show that there is a correlation of heavy Rare Earth Elements, uranium and Thorium concentrations to oxidation factor of the rocks. However this correlation was not observed for light Rare Earth Elements. It means that heavy Rare earth Elements follow the natural radionuclides in oxidation process of rocks.
    [Show full text]
  • WASH-1097.Pdf
    WASH 1097 UC-80 THE USE OF THORIUM IN NUCLEAR POWER REACTORS JUNE 1969 PREPARED BY Brookhaven National Laboratory AND THE Division of Reactor Development and Technology WITH THE ASSISTANCE OF ARGONNE NATIONAL LABORATORY BABCOCK & WILCOX GULF GENERAL ATOMIC OAK RIDGE NATIONAL LABORATORY PACIFIC NORTHWEST LABORATORY For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $1.25 FOREWORD This report on "The Use of Thorium in Nuclear Power Reactors" was prepared under the direction of the Division of Reactor Development and Technology, U.S.A.E.C., as part of an overall assessment of the Civilian Nuclear Power Program initiated in response to a request in 1966 by the Joint Committee on Atomic Energy. It represents the results of the inquiry by the Thorium Systems Task Force whose membership included representatives of Babcock & Wilcox Company, Gulf General Atomic Company, the Argonne National Laboratory, the Brookhaven National Laboratory, the Oak Ridge National Laboratory, the Pacific Northwest Laboratory, and the U.S. Atomic Energy Commission. Publication of this report, which provides information basic to the AEC reactor development program, completes one phase of the evaluation effort outlined in the 1967 Supplement to the 1962 Report to the President on Civilian Nuclear Power, issued in February 1967. The 1967 Supplement outlined changes since 1962 in the technical, economic and resource picture and provided background for further study. Specifically, this report represents the consensus of the task force on the potential use of the thorium cycle and the specific thorium fueled reactor designs which have been proposed.
    [Show full text]
  • A Review of the Benefits and Applications of the Thorium Fuel Cycle Vincent Hall University of Arkansas, Fayetteville
    University of Arkansas, Fayetteville ScholarWorks@UARK Chemical Engineering Undergraduate Honors Chemical Engineering Theses 12-2010 A review of the benefits and applications of the thorium fuel cycle Vincent Hall University of Arkansas, Fayetteville Follow this and additional works at: http://scholarworks.uark.edu/cheguht Recommended Citation Hall, Vincent, "A review of the benefits nda applications of the thorium fuel cycle" (2010). Chemical Engineering Undergraduate Honors Theses. 25. http://scholarworks.uark.edu/cheguht/25 This Thesis is brought to you for free and open access by the Chemical Engineering at ScholarWorks@UARK. It has been accepted for inclusion in Chemical Engineering Undergraduate Honors Theses by an authorized administrator of ScholarWorks@UARK. For more information, please contact [email protected], [email protected]. A REVIEW OF THE BENEFITS AND APPLICATIONS OF THE THORIUM FUEL CYCLE An Undergraduate Honors College Thesis in the Ralph E. Martin Department of Chemical Engineering College of Engineering University of Arkansas Fayetteville, AR by Vincent Hall 09-21-2010 1 Abstract This paper aims to inform the reader of the benefits that can be achieved by using thorium as a fuel for nuclear power. Stages of the thorium cycle are directly compared against the current uranium based nuclear fuel cycle. These include mining, milling, fuel fabrication, use of various reactor designs, reprocessing, and disposal. Thorium power promises several key advantages over traditional nuclear power methods, namely a dramatic decrease in long lived radioactive waste, increased fuel efficiency, greater chemical stability during disposal, and higher adaptability for differing reactor designs across a wider range of the thermal neutron spectrum.
    [Show full text]
  • Radiological Implications of Plutonium Recycle and the Use of Thorium Fuels in Power Reactor Operations
    01 RD/B/N3523 Central Electricity Generating Board Research Department Berkeley Nuclear Laboratories RADIOLOGICAL IMPLICATIONS OF PLUTONIUM RECYCLE AND THE USE OF THORIUM FUELS IN POWER REACTOR OPERATIONS By H. F. Macdonald XJ034 January 1976 DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. Radiological Implications of Plutonium Recycle and the Use of Thorium Fuels in Power Reactor Operations “ by - H.F. Macdonald Approved Head of Health Physics Research Section For inclusion in Nuclear Science Abstracts SUMMARY As economically attractive sources of natural uranium are gradually depleted attention will turn to recycling plutonium or the use of thorium fuels. In this study the radiological implications of these fuel cycles in terms of fuel handling and radioactive waste disposal are investigated in 235 relation to a conventional U enriched oxide fuel. It is suggested that a comparative study of this nature may be an important aspect of the overall optimisation of future fuel cycle strategies. It is shown that the use of thorium based fuels has distinct advan­ tages in terms of neutron dose rates from irradiated fuels and long term a decay heating commitment compared with conventional uranium/plutonium fuels. However, this introduces a y dose rate problem in the fabrication 233 and handling of unirradiated U fuels. For both plutonium and thorium fuels these radiological problems increase during storage of the fuel prior to reactor irradiation. Finally, the novel health physics problems which arise in the handling and processing of thorium fuels are reviewed in an appendix.
    [Show full text]
  • Design and Analysis of a Nuclear Reactor Core for Innovative Small Light Water Reactors
    0 Department of Nuclear Engineering And Radiation Health Physics DESIGN AND ANALYSIS OF A NUCLEAR REACTOR CORE FOR INNOVATIVE SMALL LIGHT WATER REACTORS. By Alexey I. Soldatov A DISSERTATION Submitted to Oregon State University March 9, 2009 1 AN ABSTRACT OF THE DISSERTATION OF Alexey I. Soldatov for the degree of Doctor of Philosophy in Nuclear Engineering presented on March 9, 2009. Title: Design and Analysis of a Nuclear Reactor Core for Innovative Small Light Water Reactors. Abstract approved: Todd S. Palmer In order to address the energy needs of developing countries and remote communities, Oregon State University has proposed the Multi-Application Small Light Water Reactor (MASLWR) design. In order to achieve five years of operation without refueling, use of 8% enriched fuel is necessary. This dissertation is focused on core design issues related with increased fuel enrichment (8.0%) and specific MASLWR operational conditions (such as lower operational pressure and temperature, and increased leakage due to small core). Neutron physics calculations are performed with the commercial nuclear industry tools CASMO-4 and SIMULATE-3, developed by Studsvik Scandpower Inc. The first set of results are generated from infinite lattice level calculations with CASMO-4, and focus on evaluation of the principal differences between standard PWR fuel and MASLWR fuel. Chapter 4-1 covers aspects of fuel isotopic composition changes with burnup, evaluation of kinetic parameters and reactivity coefficients. Chapter 4-2 discusses gadolinium self-shielding and shadowing effects, and subsequent impacts on power generation peaking and Reactor Control System shadowing. 2 The second aspect of the research is dedicated to core design issues, such as reflector design (chapter 4-3), burnable absorber distribution and programmed fuel burnup and fuel use strategy (chapter 4-4).
    [Show full text]
  • The Actinide Research Quarterly Is Published Quarterly to Highlight Recent Achievements and Ongoing Programs of the Nuclear Materials Technology Division
    1st quarter 2000 TheLos Actinide Alamos National Research Laboratory N u c l e a r M aQuarterly t e r i a l s R e s e a r c h a n d T e c h n o l o g y a U.S. Department of Energy Laboratory Organizers Issue an Invitation to In This Issue Plutonium Futures 1 —The Science Organizers Issue an Invitation to Plutonium Futures —The Science The second of a series of international con- have an exciting collection of some 180 invited ferences on plutonium will be held in Santa Fe, and contributed papers with topics ranging 2 NM, this summer, July 10–13. It follows the very broadly in materials science, transuranic 238Pu Aqueous highly successful 1997 conference, “Plutonium waste forms, nuclear fuels and isotopes, separa- Processing Line Will Futures - The Science,” which attracted over 300 tions, actinides in the environment, detection Provide New NMT participants representing 14 countries. The U.S. and analysis, actinide compounds and com- Capability participants, who made up about 70 percent of plexes, and condensed matter physics of ac- the total participants, came from Department of tinides. These papers, presented in separate 4 Energy national laboratories and a score of uni- oral and poster sessions, will give attendees a Editorial: versities and industries. As in 1997, the confer- chance to learn about current research outside Transactinium ence is sponsored by the Los Alamos National of their particular specialties and provide an Science Needs Laboratory in cooperation with the American opportunity for interdisciplinary discussions Educational Nuclear Society.
    [Show full text]
  • Nature No. 2468, Vol
    FEBRUARY IS, 1917J NATURE LETTERS TO THE EDITOR. and in Paris, several of them fam l-us for their atomic- weight determinations, doubt has lingered with r-egard [The Editor does not hold himself responsible for to our results for the very much more difficult case of opinions expressed by his correspondents. Neither thorium lead. In the first place, no one but myself can he undertake to return, or to correspond with has been able to obtain a suitable material by which the writers of, rejected manuscripts intended for to test the question, and I, of course, can claim no this or any other part of NATURE. No notice is previous experience of atomic-weight work. In the taken of anonymous communications.] second place, there has been an unfortunate confusion The Atomic Weight of "Thorium" Lead. between my material, Ceylon thorite, and thorianite, IN continuation of preliminary work published by a totally distinct mixed thorium and uranium Ceylon Mr. H. Hyman and myself (Trans. Chern. Soc., 1914, mineral. Lastly, there has been the widespread view, due :v., 1402) I gave an account in NATURE, February 4, to Holmes and Lawson, Fajans, and others, mainly 1915, p. 615, of the preparation of 80 grams of lead derived from geological evidence, that thorium-E, the from Ceylon thorite and of the determination of its isotope of lead resulting from the ultimate change of density in comparison with that of ordinary lead, thorium, was not sufficiently stable to accumulate over which proved the thorite lead to be 0'26 per cent. geological periods of time.
    [Show full text]
  • Indian Nuclear Power Programme & Its Linkage To
    Indian Nuclear Power Programme & its linkage to ADS S. Banerjee Bhabha Atomic Research Centre Mumbai, India 1 Contents 1. Indian nuclear power programme- present & future. 2. Nuclear fuel-cycle aspects. 3. Gains of Sub-critical reactor operation as ADS. 4. ADS for waste incineration & thorium utilization as nuclear fuel. 5. Indian efforts on ADS R&D- Roadmap, ongoing & future plans. 2 Elements of Indian nuclear programme . Indigenous development of a Reactor Technology (Pressurized Heavy Water Reactor- PHWR) - Total technology development - Based on indigenous resources . Adopting Closed-Fuel Cycle - Best use of fissile & fertile materials - Reduction of the waste burden . Three-Stage Programme - Modest uranium reserve - Utilization of large thorium reserve 3 Salient Features of PHWR • Natural Uranium Fuel - Low burn up - Efficient use of 235U per ton of U mined • Heavy Water – moderator and coolant - Development of heavy water technology - Tritium management • On-power fuelling - Fuelling machine development - Daily entry into reactor core • Neutron economy - Excellent physics design - Complex engineering - Careful choice of in-core materials - Neutrons: best utilized in fission & conversion • Large pressure vessel not required - Distributed pressure boundaries 4 Challenges faced in PHWR programme – and successfully met • Indigenous capability in fabrication of fuel and structural materials: - From low grade resources to finished fuel - Perfection in making in-core structural components • Mastering heavy water technology: - Ammonia and
    [Show full text]
  • Good Neutron Economy Is the Basis of the Fuel Cycle Flexibility in the CANDU Reactor
    SYNERGISTIC FUEL CYCLES OF THE FUTURE XA9846611 D.A. MENELEY, A.R. DASTUR Atomic Energy of Canada Ltd, Mississauga, Ontario, Canada Abstract Good neutron economy is the basis of the fuel cycle flexibility in the CANDU reactor. This paper describes the fuel cycle options available to the CANDU owner with special emphasis on resource conservation and waste management. CANDU fuel cycles with low initial fissile content operate with relatively high conversion ratio. The natural uranium cycle provides over 55 % of energy from the plutonium that is created during fuel life. Resource utilization is over 7 MWd/kg NU. This can be improved by slight enrichment (between 0.9 and 1.2 wt % U235) of the fuel. Resource utilization increases to 11 MWd/kg NU with the Slightly Enriched Uranium cycle. Thorium based cycles in CANDU operate at near-breeder efficiency. They provide attractive options when used with natural uranium or separated (reactor grade and weapons grade) plutonium as driver fuels. In the latter case, the energy from the U233 plus the initial plutonium content amounts to 3.4 GW(th).d/kg Pu-fissile. The same utilization is expected from the use of FBR plutonium in a CANDU thorium cycle. Extension of natural resource is achieved by the use of spent fuels in CANDU. The LWR/CANDU Tandem cycle leads to an additional 77 % of energy through the use of reprocessed LWR fuel (which has a fissile content of 1.6 wt %) in CANDU. Dry reprocessing of LWR fuel with the OREOX process (a more safeguardable alternative to the PUREX process) provides an additional 50 % energy.
    [Show full text]
  • Heavy Water Reactors: Status and Projected Development Designed in the Russian Federation
    01-01915_TRS407.qxd 17.04.2002 14:04 Uhr Seite 1 Technical Reports Series No. This report commences with a review of the historical development of heavy water reactors (HWRs), detailing the various national efforts made in developing reactor concepts and taking them to the stage of prototype operation or commercial viability. Sections cover HWR economics, safety and fuel cycles. 4 0 7 Technical Reports Series No. 407 The future directions likely to be taken in the development of HWR technology are addressed through discussion of three national programmes: the Canadian CANDU design, the Advanced HWR currently under development in India, and an 'Ultimate Safe' reactor being Reactors: Status and Projected Development Heavy Water designed in the Russian Federation. Heavy Water Reactors: Status and Projected Development ISBN 92–0–111502–4 ISSN 0074–1914 €99.00 INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 2002 HEAVY WATER REACTORS: STATUS AND PROJECTED DEVELOPMENT The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GREECE PARAGUAY ALBANIA GUATEMALA PERU ALGERIA HAITI PHILIPPINES ANGOLA HOLY SEE POLAND ARGENTINA HUNGARY PORTUGAL ARMENIA ICELAND QATAR AUSTRALIA INDIA REPUBLIC OF MOLDOVA AUSTRIA INDONESIA ROMANIA AZERBAIJAN IRAN, ISLAMIC REPUBLIC OF RUSSIAN FEDERATION BANGLADESH IRAQ SAUDI ARABIA BELARUS IRELAND SENEGAL BELGIUM ISRAEL SIERRA LEONE BENIN ITALY SINGAPORE BOLIVIA JAMAICA SLOVAKIA BOSNIA AND HERZEGOVINA JAPAN SLOVENIA BRAZIL JORDAN SOUTH AFRICA BULGARIA KAZAKHSTAN SPAIN BURKINA FASO KENYA SRI LANKA
    [Show full text]
  • Upper Limit of the Periodic Table and the Future Superheavy Elements
    CLASSROOM Rajarshi Ghosh Upper Limit of the Periodic Table and the Future Department of Chemistry The University of Burdwan ∗ Superheavy Elements Burdwan 713 104, India. Email: [email protected] Controversy surrounds the isolation and stability of the fu- ture transactinoid elements (after oganesson) in the periodic table. A single conclusion has not yet been drawn for the highest possible atomic number, though there are several the- oretical as well as experimental results regarding this. In this article, the scientific backgrounds of those upcoming super- heavy elements (SHE) and their proposed electronic charac- ters are briefly described. Introduction Totally 118 elements, starting from hydrogen (atomic number 1) to oganesson (atomic number 118) are accommodated in the mod- ern form of the periodic table comprising seven periods and eigh- teen groups. Total 92 natural elements (if technetium is consid- ered as natural) are there in the periodic table (up to uranium hav- ing atomic number 92). In the actinoid series, only four elements— Keywords actinium, thorium, protactinium and uranium—are natural. The Superheavy elements, actinoid rest of the eleven elements—from neptunium (atomic number 93) series, transactinoid elements, periodic table. to lawrencium (atomic number 103)—are synthetic. Elements after actinoids (i.e., from rutherfordium) are called transactinoid elements. These are also called superheavy elements (SHE) as they have very high atomic numbers. Prof. G T Seaborg had Elements after actinoids a very distinct contribution in the field of transuranium element (i.e., from synthesis. For this, Prof. Seaborg was awarded the Nobel Prize in rutherfordium) are called transactinoid elements. 1951.
    [Show full text]