Perspectives on the Age of the Earth and Why They Matter

Total Page:16

File Type:pdf, Size:1020Kb

Perspectives on the Age of the Earth and Why They Matter Perspectives on the Age of the Earth and Why They Matter Perspectives on the Age of the Earth and Why They Matter By Francis Ö. Dudás Perspectives on the Age of the Earth and Why They Matter By Francis Ö. Dudás This book first published 2020 Cambridge Scholars Publishing Lady Stephenson Library, Newcastle upon Tyne, NE6 2PA, UK British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Copyright © 2020 by Francis Ö. Dudás All rights for this book reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. ISBN (10): 1-5275-4385-4 ISBN (13): 978-1-5275-4385-0 Table of Contents Table of Contents ........................................................................................v Preface ..................................................................................................... vii Section I: We Didn’t Mean to Go to Sea ...................................................1 Chapter 1: Jennifer’s Story .........................................................................3 Chapter 2: Fast Forward ...........................................................................14 Chapter 3: Fast Forward Redux ................................................................20 Section II: The Symphony .......................................................................23 Chapter 4: Symphony Hall .......................................................................25 Chapter 5: Basics: What I Believe ............................................................34 Chapter 6: Approaching God Through Creation ......................................46 Section III: The Aweful Rowing Toward God ........................................51 Chapter 7: The Rowboat ...........................................................................53 Chapter 8: Tradition as a Way of Knowing ..............................................57 Chapter 9: Inspiration as a Way of Knowing ..........................................63 Chapter 10: Reason as a Way of Knowing ..............................................66 Chapter 11: More Limits ...........................................................................70 Chapter 12: The Problem of Scale ............................................................72 Chapter 13: More Limitations of Knowledge ...........................................78 Chpater 14: Some Caveats ........................................................................85 Chapter 15: A History of Interpretations ..................................................89 Chapter 16: Christian Creationist Perspectives ........................................95 Chapter 17: How Science Views the Age of the Earth ........................... 113 Section IV: Looking for Real Estate in Whitefish Falls ........................129 Chapter 18: A Fragment of a Memoir .................................................... 131 Chapter 19: Fresh Air .............................................................................134 Chapter 20: The Grenville Onion ........................................................... 142 Chapter 21: Thawing Out........................................................................144 Chapter 22: How Long in the Freezer? ...................................................153 Chapter 23: Vacation in the Bahamas ....................................................159 Chapter 24: Before the Oceans Came..................................................... 162 Chapter 25: The Grenville Mountain High ........................................... 165 Chapter 26: The Sudbury Dikes ............................................................. 172 vi Table of Contents Chapter 27: A Surprise ........................................................................... 175 Chapter 28: What the Huronian Has to Say ........................................... 177 Chapter 29: Before the Huronian ............................................................ 181 Chapter 30: The Core of the Onion: It’s About Time! ...........................183 Section V: The Science: A Vision Through the Keyhole ......................187 Chapter 31: Playing Musical Chairs .......................................................189 Chapter 32: Isotopic Reality ...................................................................193 Chapter 33: Developing Dating Methods ...............................................205 Chapter 34: Systematics of Radioactive Decay ......................................208 Chapter 35: Principles of Dating Analyses............................................. 218 Chapter 36: Let the Counting Begin .......................................................226 Chapter 37: We Want to Count Closed Systems ....................................241 Chapter 38: From Isotopic Ratio to Age .................................................245 Chapter 39: Specific Isotopic Systems ...................................................259 Chapter 40: Do These Systems Work in Real Life? ...............................284 Chapter 41: What About Whitefish Falls? ..............................................295 Section VI: Unloading the Camel .........................................................301 Chapter 42: Jelly Beans ..........................................................................303 Chapter 43: Frame of Reference: Uniformitarianism .............................307 Chapter 44: Robert Gentry and Radiohalos ...........................................324 Chapter 45: Non-Uniformitarian Creation Days ....................................330 Chapter 46: Challenges to Uniformitarianism .......................................337 Chapter 47: Creationist Criticism of Isotopic Dating .............................343 Chapter 48: The RATE Study ................................................................362 Chapter 49: RATE Proposal of Large-Scale Mixing .............................371 Chapter 50: RATE Evidence of Accelerated Decay ..............................376 Chapter 51: The Character of “Proof” ....................................................389 Chapter 52: What Happened to the Jelly Beans? ...................................405 Section VII: The View from 4.03 Hill ..................................................409 Chapter 53: The Search Party ................................................................. 411 Chapter 54: Time: A Many-Splendored Thing ....................................... 416 Chapter 55: The View from 4.03 Hill .....................................................436 Chapter 56: Go Tell It on the Mountain ..................................................446 Notes ....................................................................................................... 451 Glossary ..................................................................................................533 Bibliography ...........................................................................................547 Index .......................................................................................................557 Preface This book is about the gap in perception and attitude between the 44% of the US population that believes the earth is less than 10,000 years old, and those who accept the scientific determination that the earth is 4.56 billion years old. It is about investigating the age of the earth, and how that seemingly innocuous investigation links to what we think we know of science, to what we believe, and to how that knowledge and belief locate us in the context of a broader universe. It weaves together three points of view—personal anecdote, scientific and philosophical observation, and polemic. There are therefore distinct changes in tone–some sections are light reading, others are pretty dense, and yet others are, I hope, challeng- ing to our comfortably accepted views of the world. What I hope I have done in this book is to provide an entry, for a moderately literate audience, to worlds of science and philosophy that we normally do not ponder. In terms of science, this book discusses things that are more detailed than a typical high-school, or even introductory college chemistry class might discuss, but it stops well short of where research into fundamental chemical and physical principles has taken us. It is not difficult science, but it pokes its nose into an area of science that is not routinely treated in introductory textbooks. It discusses something of the philosophy of time, or perhaps more accurately, the history of the philosophy of time, to construct links between the issue of “the age of the earth” and the larger questions of philosophy, particularly the question of “how do we know?” For me, the bottom line has been the daily wonder that what we define as the laws of chemistry and physics work, reproducibly and predictably. And they work not only in the laboratory that was my home for more than a decade, but in the laboratory next door, and in the laboratory in Paris, and in the one in Beijing. There is a fundamental reality that our separate experiments describe and verify. This leads me to believe–and I use that term intentionally–that what we have measured is correct, and accurate, within the uncertainties that attend our methods. But we must be aware at all times that what we consider “natural laws” are our own descriptions–they do not, in any way, “govern”
Recommended publications
  • Natural Analogues to the Conditions
    ~E~EI3 ~IULWLiL EP~fl3TD4-1D Natural analogues to the conditions around a final repository for high-level radioactive waste Proceedings of the natural analogue workshop held at Lake Geneva, Wisconsin, U.S.A. (october 1-3,1984) John A.T. Smellie (Editor) Swedish Geological Company Uppsala, Sweden December 1984 SVENSK KARNBRANSLEFORSORJNING AB/AVDELNING KBS Swedish Nuclear Fuel Supply Co/Division KBS MAILING ADDRESS: SKBF/KBS, Box 5864, S-102 48 Stockholm, Sweden Telephone: 08-67 95 40 NATURAL ANALOGUES TO THE CONDITIONS AROUND A FINAL REPOSITORY FOR HIGH-LEVEL RADIOACTIVE WASTE PROCEEDINGS OF THE NATURAL ANALOGUE WORKSHOP HELD AT LAKE GENEVA, WISCONSIN, U.S.A. (OCTOBER 1-3, 1984) John A.T. Smellie (Editor) Swedish Geological Company Uppsala, Sweden This report concerns a study which was conducted for SKB. The conclusions and viewpoints presented in the report are those of the author(s) and do not necessarily coincide with those of the client. A list of other reports published in this series during 1985 is attached at the end of this report. Information on KBS technical re.?rts ffom 1977-1978 (TR 121), 1979 (TR 79-28), 1980 (TR 80-26),. 1981 (TR 81-17), 1982 (TR 82-28), 1983 (TR 83-77) and 1984 (TR 85-01) is available through SKB. NATURAL ANALOGUES TO THE CONDITIONS AROUND A FINAL REPOSITORY FOR HIGH-LEVEL RADIOACTIVE WASTE PROCEEDINGS OF THE NATURAL ANALOGUE WORKSHOP HELD AT LAKE GENEVA, WISCONSIN, U.S.A. (OCTOBER 1-3, 1984) John A.T. Smellie (Editor) Swedish Geological Company, Box 1424, 751 44 Uppsala The Workshop was co-sponsored by the Swedish Nuclear Fuel and Warte Management Company (SKB) and the U.S.
    [Show full text]
  • Pleochroic Haloes
    V PLEOCHROIC HALOES HE pleochroic halo has been for many years a mystery. TOccurring in enormous numbers in certain rocks, more especially in the micas of granites, and exhibiting a strange regularity of structure, it seemed more difficult of explana- tion the more it was studied. Petrographers put forward many theories to account for its origin. These we have not space to enumerate. Suffice it to say that an explanation was impossible before certain facts in radioactive science became available. We shall briefly refer, first to the appearance pre- sented by haloes, and secondly to the facts which afford the required explanation of their genesis. Finally we shall draw certain deductions not without importance. The halo is most often to be found in the iron-bearing micas-e.g., in biotite. It presents the appearance of a disk- shaped or ringshaped mark of such minute dimensions as to be entirely invisible without the aid of the microscope. When carefully measured it is found to possess a maximum radial dimension of 0.040 mm. ; but a very large number- the greater number-will be found to possess a radial dimen- sion of 0.033 mm., the larger haloes being, indeed, compara- tively scarce. There is always a minute and apparently crystalline particle occupying the centre of the full-sized halo. Figure I shows the appearance of a halo of the smaller size in mica (biotite). The light is being transmitted through a thin section of the rock. It is polarised and the intense absorption of it by the halo is clearly shown.
    [Show full text]
  • Mystery in the Rocks-Printout
    A physicist’s discovery begins an extraordinary odyssey through pride and prejudice in the scientific world. MYSTERY IN THE ROCKS By Dennis Crews he early 1960s was a time of unclouded is possible to measure both the amount of a given promise for many American college students. radioactive element and the amount of lead resulting T Industry was booming, the infamous war in from that element in a rock. Scientists correlate the Indochina had not yet ground itself into public ratio of these two amounts with the known decay rate consciousness and civil rights uprisings were the of that element, to find the period of time that has concern of only a principled few. Young elapsed since the rock was formed. (Decay rates are professionals ascended by thousands into the calculated by the half-life—the time it takes for half American dream, while visions of a home in the atoms in a given element to decay.) Many suburbia, a new car in the driveway and the promise scientists rest their proof of the earth’s age upon of a comfortable retirement beckoned still more radioactive dating of rocks that are thought to be thousands of new graduates into the mainstream. associated with the formation of the earth itself. In this setting, quests for truth and justice After acquiring his master’s degree in physics seemed the stuff of history and Hollywood hype; the Gentry staked out a promising career in the defense melodrama of moral odyssey paled beside the lure of industry, working first for Convair (later to become financial success and professional recognition.
    [Show full text]
  • Extinct Isotopes and the Age of the Earth
    The Proceedings of the International Conference on Creationism Volume 6 Print Reference: Pages 335-338 Article 29 2008 Extinct Isotopes and the Age of the Earth Don B. DeYoung Grace College Follow this and additional works at: https://digitalcommons.cedarville.edu/icc_proceedings DigitalCommons@Cedarville provides a publication platform for fully open access journals, which means that all articles are available on the Internet to all users immediately upon publication. However, the opinions and sentiments expressed by the authors of articles published in our journals do not necessarily indicate the endorsement or reflect the views of DigitalCommons@Cedarville, the Centennial Library, or Cedarville University and its employees. The authors are solely responsible for the content of their work. Please address questions to [email protected]. Browse the contents of this volume of The Proceedings of the International Conference on Creationism. Recommended Citation DeYoung, Don B. (2008) "Extinct Isotopes and the Age of the Earth," The Proceedings of the International Conference on Creationism: Vol. 6 , Article 29. Available at: https://digitalcommons.cedarville.edu/icc_proceedings/vol6/iss1/29 In A. A. Snelling (Ed.) (2008). Proceedings of the Sixth International Conference on Creationism (pp. 335–338). Pittsburgh, PA: Creation Science Fellowship and Dallas, TX: Institute for Creation Research. Extinct Isotopes and the Age of the Earth Don B. DeYoung, Ph.D., Grace College, 200 Seminary Drive, Winona Lake, IN 46590 Abstract Twenty-four extinct isotopes are presented for consideration from the recent creation worldview. These are radioactive isotopes which have decayed to abundances below the threshold of detection, leaving measurable daughter products in the process.
    [Show full text]
  • Letters to the Editor
    Letters to the editor (Figures 9-11) or at the termini of interesting and important, but it is Radiohalos in those strange tubes (Figures 12 also important to test the radio- diamonds and 14); activity of the rock in which the (b) earlier investigators claimed diamond was enclosed and not just Mark Armitage's contribution on that all the Irish7 and German8 the diamond. radiohalos in diamonds1 is a valuable halos were found only along 4. As Brown13 and Dutch14,15 have contribution to radiohalo study, but conduits within the minerals; asked, why is it that only isotopes unfortunately he omitted some very (c) Armitage's Figures 4-6 and all of polonium in the decay series of important information about radio- Gentry's figures showing Po uranium, thorium and plutonium halos necessary in their evaluation (all radiohalos unassociated with have been found to produce of which is included in an earlier cracks or conduits are found in the radiohalos? Of the 26 known paper).2 These items are as follows: mineral biotite. Biotite is isotopes of polonium there are 15 1. Armitage did acknowledge (for composed of crystals in the form not in the decay series of these example, on pages 93 and 100) of sheets. The sheets are only one elements which could be dis- that difficulties exist in explaining molecule thick. Thus in biotite tinguished if they were once the relationship between Po halo- one is never more than one-half a created within minerals and then containing rocks and sediments of molecule thickness away from a allowed to decay.
    [Show full text]
  • It Is Not Truisms Which Science Unveils. Rather It Is Part of the Greatness
    "It is not truisms which science unveils. Rather it is part of the greatness and beauty of science that we can learn through our own critical investigations that the world is utterly different from what we ever imagined - until our imagination was fired by the refutation of our earlier theories." "The wrong view of science betrays itself in the craving to be right." ...... only through criticism can knowledge advance." "the growth of our knowledge proceeds from problems (scientific inconsistencies with establishd "truth") and our attempts to solve them." Karl Popper, The Logic of Scientific Discovery. "The erroneous belief that science eventually leads to the certainty of a definitive explanation carries with it the implication that it is a grave scientific misdemeanor to have published some hypothesis that eventually is falsified. As a consequence scientists have often been loath to admit the.falsification of such an hypothesis and their lives may be wasted in defending the no longer defensible. Whereas according to Popper, falsification in whole or in part is the anticipated fate of all hypotheses, and we should even rejoice in the falsification of an hypothesis that we have cherished as our brain child. One is thereby relieved from fears and remorse and science becomes an exhilirating adventure where imagination and ·vision lead to conceptual developments transcending in generality and range the experimental evidence. The precise formation of these imaginative insights into hypotheses opens the way to the most rigorous testing by experiment, it being always anticipated that the hypothesis may be fa~sified and that it will be replaced in whole or in part by another hypothesis of greater explanatory power." J.
    [Show full text]
  • Occurrence of Uranium in Rocks of the Ekiek Creek Complex, Western Alaska
    UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Occurrence of Uranium in Rocks of the Ekiek Creek Complex, Western Alaska by Alan R. Wallace Open-File Report 79-1653 1979 This report is preliminary and has not been edited or reviewed for conformity with U.S. Geological Survey standards. CONTENTS Page Abstract................................................................. 1 Introduction.............................................................2 Acknowledgments.......................................................... 2 Regional and geologic setting............................................2 Methods of study.........................................................4 Geology..................................................................5 Petrography......................................................... 7 Orthoclase-nepheli ne syenite....................................7 Mica pyroxenite.................................................9 Contact zone rocks..............................................9 Monzonite......................................................12 Uranium occurrence and distribution................................12 Di scussion..............................................................16 References.............................................................. 19 Figures Page Figure 1. Location and general geology of the Kobuk-Selawik Lowlands, including the Ekiek Creek Complex................3 2. Diagrammatic illustration of field relations, Ekiek Creek Complex...............................................6
    [Show full text]
  • The Development of Pleochroic Haloes and the Alpha Radioactivity of the Nucleus Minerals*
    MINERALOGICAL JOURNAL , VOL. 1, No. 4, PP. 213-223, JUNE, 1955 THE DEVELOPMENT OF PLEOCHROIC HALOES AND THE ALPHA RADIOACTIVITY OF THE NUCLEUS MINERALS* ICHIKAZU HAYASE Geological and Mineralogical Institute , Faculty of Science, University of Kyoto ABSTRACT The pleochroic halo has been regarded as the index of the geologic age of rocks, especially of granite. The autoradiographic studies now enable us to measure the alpha radioactivity even of a single grain of minute mineral and to determine more perfectly the evolution of the halo produced around it . Thus the geologic age of a rock can be determined more easily . In this paper are treated the development of haloes and the radioactive homogeneity of the minute minerals in their nuclei. Introduction The varieties of minute radioactive minerals contained in thin sections of granite were examined by an autoradiographic method , with the nuclear emulsion ET-2E (Fuji Photo Film Co. Ltd.). From this test the author was informed that the varieties of minute radioactive minerals were included in granite and that two grain belonging to the same variety were often quite different in their radioactive order2). To be measured by this method are the alpha tracks expelled from each grain of such minute minerals. If such a grain has been in cluded in biotite, there is always to be seen a pleochroic halo, whose blackness depends upon the alpha radioactivity of the grain as well as upon the geologic age of the grain and accordingly of * Read at the meeting of the Kansai Branch of the Geological Society of Japan, on September 25, 1954.
    [Show full text]
  • V21N3 the Regression of Modern Science Part 5
    Vol. 21, No. 3 Page 1 FOUNDATIONS OF SCIENCE AUGUST 2018 The Journal of Common Sense Science FOUNDATIONS August 2018 Volume 21 OF SCIENCE Number 3 The Regression of Modern Science Part 5 The Age of the Earth Charles William (Bill) Lucas, Jr. 29045 Livingston Drive Mechanicsville, MD 20659 [email protected] Abstract. The reduction of the role of logic in modern (CMB), the large scale structure of the universe science has led to the false or incomplete theories of and Hubble's law. If the known laws of physics are electrodynamics, gravitation, strong interaction, weak used to extrapolate backwards in time to the highest interaction, special and general relativity, quantum density regime, the result is a singularity which is mechanics, the chemical atom, the atomic nucleus, the associated with the Big Bang. Measurements of the standard model of elementary particles, the Big Bang current expansion rate of the universe based on the Theory of the origin of the universe, the abiogenesis observed Hubble redshifts being interpreted as origin of life, and an age of the earth of 4.5 billion Doppler red shifts place the Big Bang at around years. This is known as the regression of modern 13.8 billion years ago, which is thus considered to be science. The solution to the problem is to properly the age of the universe. After the initial expansion, the combine the axiomatic (logical) and empirical universe cooled sufficiently to allow the formation (experimental) scientific methods in such a manner of subatomic particles, and later simple atoms like that the full potential of logic, experiment and hydrogen and helium.
    [Show full text]
  • Uraninite from the Guangshigou Pegmatite-Type Uranium Deposit in the North Qinling Orogen, Central China
    minerals Article Uraninite from the Guangshigou Pegmatite-Type Uranium Deposit in the North Qinling Orogen, Central China: Its Occurrence, Alteration and Implications for Post-Caledonian Uranium Circulation Bin Wu 1,*, Christophe Bonnetti 1, Yue Liu 2, Zhan-Shi Zhang 1,*, Guo-Lin Guo 1 , Guang-Lai Li 1, Yin-Qiu Hu 1 and Zhao-Yan Yan 1 1 State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China; [email protected] (C.B.); [email protected] (G.-L.G.); [email protected] (G.-L.L.); [email protected] (Y.-Q.H.); [email protected] (Z.-Y.Y.) 2 Information Engineering School, Jiangxi College of Applied Technology, Ganzhou 341000, China; [email protected] * Correspondence: [email protected] (B.W.); [email protected] (Z.-S.Z.); Tel.: +86-791-83897801 (B.W.); +86-791-83897617 (Z.-S.Z.) Abstract: The Guangshigou deposit is the largest pegmatite-type uranium deposit in the Shangdan domain of the North Qinling Orogenic Belt, which is characterized by the enrichment of uraninite hosted in biotite granitic pegmatites. At Guangshigou, uraninite commonly occurs as mineral inclu- sions in quartz, K-feldspar and biotite or in interstices of these rock-forming minerals with magmatic Citation: Wu, B.; Bonnetti, C.; Liu, Y.; characteristics (e.g., U/Th < 100, high ThO ,Y O and REE O contents and low concentrations Zhang, Z.-S.; Guo, G.-L.; Li, G.-L.; Hu, 2 2 3 2 3 Y.-Q.; Yan, Z.-Y. Uraninite from the of CaO, FeO and SiO2). It crystallized at 407.6 ± 2.9 Ma from fractionated calc-alkaline high-K ◦ Guangshigou Pegmatite-Type pegmatitic melts under conditions of 470–700 C and 2.4–3.4 kbar as deduced by the compositions of Uranium Deposit in the North coexisting peritectic biotite.
    [Show full text]
  • Chsr&Itristics and Significance of Uranium Bearing Fan African Younger Granite in the Eastern Desert
    EG0000327 Tlu?'l--'ri'!i C'unfciTncc on the Peaceful Uses ofAtonm. t^nmsy, uurnascus y - u uec. IVVb AAEA Chsr&itristics and Significance of Uranium Bearing Fan African Younger Granite in the Eastern Desert, Egypt M. A, Hassan, G.A. Dabbour and T.F. Mohammden Nuclear .vlntonals Authority, P.O. Box 530, Maadi, ;\;)i!;innya. Cairo. Egypt. J.". ; . ; . -c> •-, --S, •'. ~ )__•; j • ~''i-J I t I • "<• • --*> I I i p •• v_a V I f j J-LJ *LJL_J I *\ l I 4_J_J y -^ I I tj a, , ^i I ( .-j—^UJi _wi ^' > ". > '•• i j. ^ H J " ^ 1 I 6JJ& o 'I ^." 4 • 11 -y II \ MjljjJI .JI.J (] l^| :.-• ;!—•—•-=-• ;.-{' d—~:L'_i La—i—G_2W L^_i I ,i_a. j Ji.)...L.-k <—LJI—i ft \ S j) \ -^ 1 I j < ' a J ^JJ "' * ; _ •—-o—j K~i j t J_J X-2i_j jk_j j_i j . 4—J j I -»j—I_J I jj-i • .' ' •''J _) yj .'J ' ^••* J- ~Q CJV I ft "i -^ I ..--.Vwj _ftJU ^..^J i j jj I ^J -^ A :_^_< L'.'i .vj I j..^..l ' ^-* fr J *^. i J **> ^'. M • . • •• I j j 1 I r- •_.• • _c—> . .i -1. yjj i 1__^ij ( • J a 4 i a I y^i. 6 •, " ' I I ^' ,,,.| I ) jJ I • f • -y ^ •. c JJ I — " ' ' *' * *' I i •? t I I • L -• ! _^ja_J ui yJt-IiJ 1 J i O_ul Jfcij I a JJ& CjjLJft J_JS a _ -::• t ''I v -^ J ( i T V -^ _i djj " Abstract Surficial uranium mineralization was discoverd in lour Pan African younger granite plutons in the Eastern Desert of Egypt.
    [Show full text]
  • Est Expenditure. Especially in the Conway Granite. Whitfield6
    THE CONWAY GRANITE OF NEW HAM1PSHIRE AS A MlAJOR LOW-GRADE THORIUM RESOURCE BY J. A. S. ADAMS, M.-C. KLINE, K. A. RICHARDSON, AND J. J. W. ROGERS DEPARTMENT OF GEOLOGY, WILLIAM MARSH RICE UNIVERSITY, HOUSTON, TEXAS Communicated by M. King Hubbert, September 21, 1962 Before the present work was undertaken, the reserves of thorium at all ore grades in the United States were much less than those of uranium. All recent studies agreed on this point, and a report of the U. S. Atomic Energy Commission1 con- cluded: "In summary, both reserves and potential annual production of uranium must be considered to be several times those of thorium at current prices, but at some price, presumably many times the present price, thorium availability might approach that of uranium." McKelvey,2 among others, accepted the conclusion that this difference in reserves was also an indication of relative availability. The relative availability of thorium and uranium is of current importance in considering what types of nuclear-energy systems to investigate and develop. In reactors oper- ating in the thermal- and intermediate-neutron energy range, thorium-based fuel cycles have the advantage of higher conversion ratios, longer reactivity lifetimes, and lower fuel costs than are possible with natural uranium-based fuel cycles. Thorium-fueled reactors also have long-term potential for thermal breeding. Numerous hypotheses and arguments can be advanced to support the conclusion that the lower relative availability of thorium is real; there are also some indications that it may be only apparent. To resolve this question of relative thorium avail- ability, more data are needed beyond those already available.3 The present work was undertaken under Subcontract 1491 with the Oak Ridge National Laboratory to determine how much of this necessary information could be obtained with a mod- est expenditure.
    [Show full text]