Gmelin Handbook of lnorganic Chemistry

8th Edition

Gmelin Handbock Volumes on Radium and Actinides

Ac Actinium* - 1942 Actinium Suppl. Vol. 1 - 1981

Np,Pu ... PartA1, I (New Suppl. Series Vol. Nr. 7 a) } - 1973 Part A 1, II" (New Suppl. Series Vol. Nr. 7 b) (Elements) - 1974 Part A2o (New Suppl. Series Vol. Nr. 8) - 1973

Part B 1 o (New Suppl. Series Vol. Nr. 31) (Metals) - 1976

Part B2* (New Suppl. Series Vol. Nr. 38) } (AIIoys)

- 1976 Part B3* (New Suppl. Series Vol. Nr. 39) - 1977

Part Co (New Suppl. Series Vol. Nr. 4) (Compounds) - 1972

Part D 1 o (New Suppl. Series Vol. Nr. 20) } (Chemistry in Solution)

- 1975 Part D2o (New Suppl. Series Vol. Nr. 21) - 1975

Index- 1979

Pa Protactinium Main Volume* - 1942 Protactinium Suppl. Vol. 1 o (Element) - 1977

Ra

Th

u

Protactinium Suppl. Vol. 2° (Metal. Alloys. Compounds. Chemistry in Solution) - 1977

Radium Main Volume* Radium Suppl. Vol. 1 *

Radium Suppl. Vol. 2

Thorium Main Volume* Thorium Suppl. Vol. C1 *

Thorium Suppl. Vol. C2 *

Uranium Main Valurne * Uranium Suppl. Vol. A 1 * Uranium Suppl. Vol. A2o Uranium Suppl. Vol. A3 * Uranium Suppl. Vol. A4 Uranium Suppl. Vol. C1 *

Uranium Suppl. Vol. C2 *

Uranium Suppl. Vol. C3 * Uranium Suppl. Vol. er Uranium Suppl. Vol. C8* Uranium Suppl. Vol. C9 Uranium Suppl. Vol. C11

Uranium Suppl. Vol. C14 Uranium Suppl. Vol. D2 Uranium Suppl. Vol. E1 Uranium Suppl. Vol. E2o

Completely or o in part in German

- 1928 (History. Cosmochemistry. Geochemistry) - 1977 (Element. Compounds) - 1977

- 1955 (Compounds with Rare Gases, Hydrogen, Oxygen) - 1978 (Ternary and Polynary Oxides) - 1976

- 1936 (Uranium Deposits) - 1979 (Isotopes) - 1980 (Technology. Uses) - 1981 (lrradiated Fuel. Reprocessing) -1982(present volume) (Compounds with Rare Gases and Hydrogen. Uranium-Oxygen System) - 1977 (U 3 0 8 and U0 3 Oxides. Hydroxides and Oxide Hydrates. Peroxides) - 1978 (Ternary and Polynary Oxides) - 1975 (Compounds with Nitrogen) - 1981 (Compounds with Fluorine) - 1980 (Compounds with Chlorine, Bromine,lodine) -1979 (Compounds with Selenium, Tellurium, and Baron)- 1981 (Compounds with P, As, Sb, Bi, Ge) - 1981 (Solvent Extraction) - 1982 (Coordination Compounds) - 1979 (Coordination Compounds) - 1980

Grnelin Handbuch der Anorganischen Chemie

BEGRÜNDET VON

ACHTE AUFLAGE BEGONNEN

FORTGEFÜHRT VON

HERAUSGEGEBEN VOM

Achte völlig neu bearbeitete Auflage

Leopold Gmelin

im Auftrag der Deutschen Chemischen Gesellschaft von R. J. Meyer

E. H. E. Pietsch und A. Kotowski Margot Becke-Goehring

Gmelin-lnstitut für Anorganische Chemie der Max-Pianck-Gesellschaft zur Förderung der Wissen­schaften Direktor: Ekkehard Fluck

Springer-Verlag Berlin Heidelberg GmbH 1982

Gmelin-lnstitut für Anorganische Chemie der Max-Pianck-Gesellschaft zur Förderung der Wissenschaften

KURATORIUM (ADVISORY BOARD)

Dr. J. Schaafhausen, Vorsitzender (Hoechst AG, Frankfurt/Main-Höchst), Dr. G. Breil (RuhrchemieAG, Oberhausen-Holten), Dr. G. Broja (Bayer AG, Leverkusen), Prof. Dr. G. Fritz (Universität Karlsruhe), Prof. Dr. N. N. Greenwood (University of Leeds), Prof. Dr. R. Hoppe (Universität Gießen), Prof. Dr. R. Lüst ( Präsidentder Max-Pianck-Gesellschaft, München), Dr. H. Moell (BASF-Aktiengesellschaft, Ludwigshafen), Prof. Dr. E. L. Muetterties (University of California,Berkeley,California), Prof. Dr. H. Nöth (Universität München), Prof. Dr.A. Rabenau (Max-Pianck-lnstitut für Festkörperforschung, Stuttgart), Prof. Dr. Dr. h.c. mult. G. Wilke (Max-Pianck-lnstitut für Kohlenforschung, Mülheim/Ruhr)

DIREKTOR (DIRECTOR)

Prof. Dr. Dr. h.c. Ekkehard Fluck

HAUPTREDAKTEURE (CHIEF EDITORS)

STELLVERTRETENDER DIREKTOR (DEPUTY DIRECTOR)

Dr. W. Lippert

Dr. K.-C. Buschbeck, Ständiger Hauptredakteur Dr. H. Bergmann, Dr. H. Bitterer, Dr. H. Katscher, Dr. R. Keim, Dipl.-lng. G. Kirschstein, Dipi.­Phys. D. Koschel, Dr. U. Krüerke, Dr. H. K. Kugler, Dr. E. Schleitzer- Rust, Dr. A. Slawisch, Dr. K. Swars, Dr. B. v. Tschirschnitz-Geibler, Dr. R. Warncke

MITARBEITER (STAFF)

Z. Amerl, D. Barthel, Dr. N. Baumann, I. Baumhauer, Dr. K. Beeker, Dr. W. Behrendt, Dr. L. Berg, Dipi.-Chem. E. Best, M. Brandes, E. Brettschneider, E. Cloos, Dipi.-Phys. G. Czack, I. Deim, Dipi.-Chem. H. Demmer, R. Dombrowsky, R. Dowideit, Dipi.-Chem.A. Drechsler, Dipi:-Chem. M. Drößmar, M. Engels, Dr. H.-J. Fachmann, Dr. J. Faust, I. Fischer, Dr. R. Froböse, J. Füssel, Dipl.-lng. N. Gagel, Dipi.-Chem. H. Gedschold, E. Gerhardt, Dr. U. W. Gerwarth, M.-L. Gerwien, Dipi.-Phys. D. Gras, Dr. V. Haase, H. Hartwig, B. Heibel, Dipi.-Min. H. Hein, G. Heinrich-Sterze!, H.-P. Hente, H. W. Herold, U. Hettwer, U. Hilberger, Dr. I. Hinz, Dr. W. Hoffmann, Dipi.-Chem. K. Holzapfel, Dipi.-Chem. W. Karl, H.-G. Karrenberg, Dipi.-Phys. H. Keller-Rudek, I. Knauss, Dipi.-Phys. E. Koch, Dr. E. Koch, Dipi.-Chem. K. Koeber, Dipi.-Chem. H. Köttelwesch, R. Kalb, E. Kranz, Dipi.-Chem. I. Kreuzbichler, Dr. A. Kubny, Dr. P. Kuhn, M. Langer, M.-L. Lenz, Dr. A. Leonard, Dipi.-Chem. H. List, H.Mathis, E. Meinhard, Dr. P. Merlet, K. Meyer, M. Michel, K. Nöring, C. Pielenz, E. Preißer, I. Rangnow, Dipi.-Phys. H.-J. Richter­Ditten, Dipi.-Chem. H. Rieger, E. Rieth, Dr. J. F. Rounsaville, E. Rudolph, G. Rudolph, Dipi.­Chem. S. Ruprecht, D. Schädle, V. Schlicht, Dipi.-Chem. D. Schneider, Dr. F. Schröder, Dipi.­Min. P. Schubert, A. Schwärze!, Dipl.-lng. H. M. Somer, E. Sommer, Dr. P. Stieß, M. Teichmann, Dr. W. Töpper, U. Trautwein, Dipl.-lng. H. Vanecek, Dipi.-Chem. P. Velic, Dipl.­lng. U. Vetter, Dipi.-Phys. J. Wagner, R. Wagner, Dipi.-Chem. S. Waschk, Dr. G. Weinberger, Dr. H. Wendt, Dr. B. Wöbke, K. Wolff, Dr. A. Zelle, U. Ziegler

FREIE MITARBEITER (CORRESPONDENT MEMBERS OF THE SCIENTIFIC STAFF)

Dr. I. Kubach, Prof. Dr. P. F. Linde, Prof. Dr. Y. Marcus, Dr. K. Rumpf, Dr. R. C. Sangster, Dr. R. P. Taylor, Dr. U. Trobisch

EM. WISSENSCHAFTLICHES MITGLIED

(EMERITUS MEMBER OF THE INSTITUTE)

AUSWÄRTIGE WISSENSCHAFTLICHE MITGLIEDER

(CORRESPONDENT MEMBERS OF THE INSTITUTE)

Prof. Dr. Dr. E. h. Margot Becke

Prof. Dr. Hans Bock Prof. Dr. Dr. Alois Haas, Sc. D. (Cantab.)

Grnelin Handbook of lnorganic Chemistry

AUTHORS

CHIEF EDITORS

8th Edition

u Uranium Supplement Valurne A4

Behavior of Uranium Fuels in Nuclear Reactors. Reprocessing of Spent Nuclear Fuels

With 173 illustrations

Helmut Aßmann, Kraftwerk Union AG, Erlangen

Erich Merz, Kernforschungsanlage, Jülich

Aristides Naoumidis, Kernforschungsanlage, Jülich

Hubertus Nickel, Kernforschungsanlage, Jülich

Heinz Stehle, Kraftwerk Union AG, Erlangen

Gilbert N. Walton, Department of Chemical Engineering and Chemical Technology, Imperial College, London University, London, U.K.

Kari-Christian Buschbeck, Gmelin-lnstitut, Frankfurt am Main

Cornelius Keller, Supervising scientific coordinator for the Uranium Supplement Volumes, Schule für Kerntechnik, Kernforschungszentrum Karlsruhe

System Number 55

Springer-Verlag Berlin Heidelberg GmbH 1982

LITERATURE CLOSING DATE: END OF 1979

IN MANY GASES MORE REGENT DATA HAVE BEEN CONSIDERED

Library of Congress Catalog Card Number: Agr 25-1383

ISBN 978-3-662-06016-2 ISBN 978-3-662-06014-8 (eBook) DOI 10.1007/978-3-662-06014-8

This work is subject to copyright. All rights are reserved whether the whole or part of the material is concerned specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machine or similar means, and storage in data banks. Under §54 of the German Copyright Law where copies are made for other then for private use, a Iee is payable to "Verwertungsgesellschaft Wort", Munich.

© by Springer- Verlag Berlin Heidelberg 1981

Originally published by Springer-Verlag, Berlin · Heidelberg · New York 1981 Softcoverreprint of the hardcover8th edition 1981

The use of generat descriptive names, trade marks, etc. in the Gmelin Handbook, even if the !armer arenot especially identified, is not tobe taken as a sign !hat such names, as understood by the Trade Marksand Merchandise Marks Act, may according be used freely by anyone.

Preface

The present volume A4 of the "Uranium" series of the Gmelin Handbook deals with two very important technological aspects of the nuclear fuel cycle:

- the behavior of fuel elements during burnup in a nuclear reactor, and - the reprocessing of spent fuel to recover the non-fissioned uranium and newly created materials.

The usefullifetime of a fuel element in a nuclear reactor depends strongly on the change of its chemical and physical properties during irradiation. Properties like thermal conductivity, swelling, creep, and oxygen-to-metal ratio are strongly affected by the intense neutron field and the energetic fission products. Furthermore, the high temperature gradient in a fuel element also produces alterations of the initial fuel. such as densification or U: Pu segregation. All of these effects are thoroughly discussed for the different kinds of fuels to be used in modern nuclear reactors today or in the future. The vast amount of very often Contradietory results in sometimes difficultly obtainable Iiterature has been summarized to create a compendium in this field with the two sections, on oxide and on carbide and nitride fuels, respectively.

The chapters on reprocessing of spent fuels deal only with fuel elements of the uranium­thorium fuel cycle and with those containing fuel highly enriched in 235U. The treatment of U02

and (U,Pu)02 has already been given in the transuranic element series.

Due to the vast amount of Iiterature published within the topics of this book, only selected and important papers have been mentioned here. For other references see the "General References" etc. in this book. The Iiterature is evaluated for the period up to the end of 1979, in many cases more recent Iiterature has been considered.

I thank the authors from industry and the nuclear research centers for their excellent collaboration. I thank also the Gmelin Institute, with Prof. Dr. Y. Marcus, who translated the originally German text into English, Dr. K. C. Buschbeck as the supervising editor and Prof. Dr. Dr. h.c. E. Fluck as director, for its support and encouragement.

Frankfurt am Main December 1981 Cornelius Keller

Table of Contents

1 The Behavior of Uranium Fuels in Nuclear Reactors.

1.1 Oxide Fuels . .

lntroduction and Survey

1.1.1 Effects of the Fission Fragments in the Crystal Lattice

Properties of the Fission Fragment Spike . . lncreased Seit-Diffusion . . . . . . . . . . Formation and Annealing of Lattice Defects .

1.1 .2 Mechanical Behavior . . . . . . . . .

Elastic Behavior. . . . . . . . . . . . . . Plastic Behavior and Behavior upon Fracture Creep Behavior . . . .

Theoretical Models . . . . . Experimental Results . . . . Primary and Transient Creep .

1.1.3 Thermal Behavior. . . . .

Thermal Conductivity and Conductivity Integral of U02 .

Experimental Results . . . . . . . . . . . . . . . Thermal Expansion and Specific Heat Capacity. . . . .

1.1 .4 Behavior of the Fission Products and Release of Fission Gases

Concentration of the Fission Products. Solid and Volatile Fission Products . . . . .

Fission Products in the Fuel . . . . . . . The Behavior of Volatile Fission Products .

Behavior of the Fission Gases in the Fuel The Formation and Growth of Bubbles Bubble Migration .....

The Release of Fission Gases .. Experimental . . . . . . . . Models for Low Tamperatures Models for Intermediate Tamperatures Model for High Tamperatures .... The Diffusion Coefficient of Fission Gases

Page

1

3

5

5 8 8

11

11 12 14 17 19 26

29

29 30 35

39

40 40 41 44 45 46 48 50 50 50 51 63 64

1.1.5 Changes in Dimensions lnduced by Irradiation (Densification and Swelling) . 70

lrradiation-lnduced Densification . . . . . . . . . . . . . . . . . . . . . . . 71 Theoretical Models for Thermally Activated and lrradiation-lnduced Densification 71 Experimental Studies . . . 77

Swelling by Fission Products. . . . 80 Experimental Results . . . . . . 80 Mechanistic and Empirical Models 84

The Superposition of Swelling, Densification, and Other Deformative Phenomena . 86

II

1.1 .6 Restructuring. . . . . . . . . . . . . . . . .

Phenomenological Description of the Structural Zones Crack Patterns and Relocation Grain Growth. . . . .

Theoretical Models . . . . Experimental Results . . .

Pore Migration, Columnar Grain Growth, Central Void

1.1.7 Changes in the Stoichiometry, Redistribution of Oxygen and Uranium/

Page 92

92 95 98 98 99

102

Plutonium . . . . . . . 106

Thermodynamic Data Base. . Changes in the Stoichiometry

Fuel in Steel Cladding. . Fuel in Zircaloy Cladding .

Redistribution of Oxygen . . Redistribution of Uranium and Plutonium in a Mixed Oxide.

1.1.8 Interaction with the Cladding ..

107 110 110 112 112 118

123

lnterior Corrosion in Zircaloy Cladding 124 lnterior Corrosion in Steel Cladding. . 124 Cooperative Mechanical and Chemical lnteractions. 126

Mechanical Interaction between Fuel and Cladding 126 Stress Corrosion Cracking (SCC) Arising from Pellet/Ciad Interaction (PCI) 127

1.1.9 Behavior of Oxidic Nuclear Fuels in Defective Fuel Rods.

Water Cooled Fuel Elements . Sodium Cooled Fuel Elements . . . . . .

1.2 Carbide and Nitride Nuclear Fuels.

1.2.1 lntroduction . . . . . . . . . . . .

1.2.2 Properties in the Non-lrradiated State

Mechanical Properties . Creep Behavior . . . . . .

Carbides ....... . Nitrides, Carbide Nitrides

Elastic Properties Strength . . . . Hardness ....

Thermal Properties Coefficient of Thermal Expansion.

Carbides ....... . Nitrides, Carbide Nitrides

Thermal Conductivity Carbides. Nitrides .... .

Diffusion ...... . Seit-Diffusion in Uranium Carbides.

Effect of the Composition on the Diffusion of Uranium.

135

135 137

139

139

142

143 143 143 146 148 150 151 153 153 153 154 156 156 160 164 164 165

III

Page Effect of lmpurities on the Diffusion of Uranium. 166 Effect of Nitrogen on the Diffusion of Uranium 167 Diffusion of Other Actinides in Carbides . . . 167 The Contribution of Grain-Boundary Diffusion 168

Diffusion of Carbon in Carbides . . . . . . . . 169 The Effect of Nitrogen on the Mobility of the Carbon 170

Self-Diffusion of Metal Atoms in Nitrides. . . . . 170 Diffusion of Nitrogen in Nitrides . . . . . . . . . 171 Diffusion of Fission Gases in Carbides and Nitrides 171

Electrical Resistivity . 175 Carbides . . . . . . . . . . . . 175 Nitrides . . . . . . . . . . . . 177

Compatibility with Metallic Materials 180 Compatibility of Carbidic Fuels and Breeding Materials with Austenitic Steels 180 Compatibility of UC with Other Metallic Materials . . . . 184 Compatibility of (U,Pu)C with Various Cladding Materials 185 Compatibility of Nitride Fuels with the Cladding. 187 Compatibility of Uranium Carbide Nitrides. . . . . . . . 188

1 .2.3 Irradiation Behavior. . . . . . . . . . 191

Changes in the Physical Properties . . . . . 191 lrradiation-lnduced Creep Processes in UC and UN 191 Irradiation Effects on Diffusional Processes 192 Change of the Hardness on Irradiation 193 Changes ofThermal Conductivity . 194 Changes of the Electrical Resistivity 195

In-Pile Compatibility. . . . . . . . . 196 Carbide Fuels. . . . . . . . . . . 196

Results of Irradiation of UC with Cr-Ni Steels. 197 UC with Tungsten . . . . . 198 UCwithNb-1%Zr..... 198 (U,Pu)C with Stainless Steel 198 (U,Pu)C with Nb-1% Zr 201

Nitride Fuels . . . . . . . 201 lrradiation-lnduced Swelling . 204

Uranium Carbide . . . . . 204 lrradiation-lnduced Swelling of (U,Pu)C Mixed Carbides. 209 Nitride and Nitrogen-Containing Carbide Fuels: UN, U(C,N). (U,Pu)N, and (U,Pu)(C,N) . . . . . . . . . . . . . . . . . . . . . 214 Mechanism of the Swelling of Carbide and Nitride Fuels . 218

The Release of Gaseous Fission Products . 227 Mechanisms of the Fission Gas Release. . . . . . . . . 227 Fission Gas Release from UC . . . . . . . . . . . . . 228

The Temperature Dependence of the Fission Gas Release from UC 228 Effect of the Stoichiometry on the Fission Gas Release from UC 230 Effect of the Porosity and the Microstructure . 231 Effect of the Burnup and of the Power Density 233

Fission Gas Release from (U,Pu)C . . 234 Fission Gas Release from Nitride Fuels . . . . . 241

IV

The Behavior of Solid Fission Products and of Plutonium in Carbide and Nitride Fuels during Irradiation . . . . . . . . . . . . . . . . . . . . .

Solid Fission Products in the Fuel . . . . . . . . . . . . . . . The Distribution of Plutonium in Carbide and Nitride Fuels . . . . Interaction of the Fuel and the Fission Products with the Cladding

2 Reprocessing of Spent Nuclear Fuels

2.1 lntroduction . . . . . . . . . . . .

2.2 Reprocessing of Spent Fuel of the U-Pu Nuclear Fuel Cycles

2.3 The Reprocessing of Enriched 235 U Fuels

2.3.1 I ntroduction . . . . . .

2.3.2 Storage of lrradiated Fuel

2.3.3 Disassembly of Fuel . .

Mechanical Operations . . . Chemical Methods of Decladding and Dissolution

Aluminium Based Fuel Uranium Metal . . . . . . Zirconium Based Fuel . . . Stainless Steel Canned Fuel Other Types of Fuel.

2.3.4 Dissolvers . . . .

2.3.5 Solvent Extraction

2.3.6 Pyrometallurgical Processing.

lntroduction . . . Fluoride Volatility . Melt Processing. .

2.4 Reprocessing of Spent 232Th- 233 U Fuels . . . . . .

2.4.1 Application of the Thorium Cycle for Energy Production

Nuclear Reactions and the Buildup of Actinides in the Thorium Cycle The Use of Thorium in Various Reactor Systems . Types of Fuel Elements . . . . . . . . . .

2.4.2 Classification of Reprocessing Methods.

Page

250 251 254 256

258

258

258

259

259

262

262

262 263 263 264 264 265 265

266

268

272

272 273 273

276

276

276 277 278

283

Listing of the Processes . . . . . . . . . . 284 The History of the Development of 232Th- 233 U Reprocessing 286 Composition of the lrradiated Fuel Elements . . . . . . . . 289

2.4.3 Head-End Processing of lrradiated Thorium-Containing Fuel Elements. 293

Removal of the Metallic Cladding of the Fuel . . . . . . . . . . . . . . 294 Removal of the Pyrolytic Carbon Coating and of the Graphite Matrix of HTR Fuel Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

Dissolution of Thorium-Containing Fuels and Fertile Materials. Treatment of the Off-Gases . . . . . . . . . . . . . . Adjustment of the Feed Solution . . . . . . . . . . . .

2.4.4 Chemical Separation by Means of Solvent Extraction

Chemistry of the Aqueous Process Solution . . Choice of the Extraction System . . . . . . . Characteristics of the Processes and the Plants. Extraction with Ketones Extraction with Ethers . . . . . . . . . . . Extraction as Chelates . . . . . . . . . . . Extraction with Alkylphosphorus Compounds Extraction with Amines . . . . . . . . . .

2.4.5 Extractive Reprocessing of Thorium-Containing Nuclear Fuels and Breeding

V

Page 298 300 302

310

310 310 310 311 312 312 312 313

Materials with the HN0 3 -TBP-Kerosene System 317

General Aspects. . . . . . . . . . . . . . . . . . . . . The Chemistry of the Separation . . . . . . . . . . . . . Chemical and Radiation-Chemical Stability of the Extractant The THOREX Process . . . . . . . . . . . . . . . . . .

2.4.6 Chemical Separation by Means of Sorption and Ion Exchange

317 317 319 320

326

Primary Separation by Ion Exchange . . . . . . . . . . . . . . 327 Purification of the Uranium Product by Sorption and Ion Exchange 328 Extraction Chromatography . . . . . . . . . . . . . . . . 329

2.4.7 Reprocessing by Means of Halide Volatilization Processes 332

Fluorination of Solids . . . 333 Fluorination of Malten Salts 334 Purification of UF6 • • • • 335 Chlorination of Solids . . . 336

2.4.8 Reprocessing by Application of Pyrochemical Processes 341

Fractional Crystallization and Distillation. . . . . . . 342 Distribution between lmmiscible Metal and Salt Melts 343 Oxidation-Reduction Reactions, Slag Formation . . 344 Electrochemical Separation Processes . . . . . . . 345

2.4.9 Refabrication of New Nuclear Fuels from 233U 349

Radiation Safety Provisions in the Handling of 233U 349 Processes for the Refabrication of 233 U Fuels . . . 350 Production of Fuel Particles for the Recycling of 233 U in Advanced Reactor Systems 351

Table of Gonversion Factors . . . . . . . . . . . . . . . . . . . . . . . . 358