A present review of the thorium nuclear fuel cycles

Directorate-General For Research And Innovation European Commission

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Nuclear energy and safety

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• Publié par: DIRECTORATE-GENERAL-FOR-RESEARCH-AND-INNOVATION-EUROPEAN-COMMISSION
• Nombre de lectures: 6
• Langue: English
• Poids de l'ouvrage: 10 Mo

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ISSN 1018-5593
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European Commission
nuclear science
and technology
A present review of the thorium
nuclear fuel cycles
7
π m
Report
EUR 17771 EN European Commission
nuclear science
and technology
A present review of the thorium
nuclear fuel cycles
M. Lung
Consultant
30, Tour d'Echelle
F-78750 Mareil-Marly
Contract No FI2W/CT94-0131
Final report
Research work performed in the framework of the fourth R&D programme on
'Management and Storage of Radioactive Waste'
(1990-94) of the European Atomic Energy Community
Directorate-General
Science, Research and Development
1997 EUR 17771 EN LEGAL NOTICE
Neither the European Commission nor any person acting on behalf of the Commission
is responsible for the use which might be made of the following information
A great deal of additional information on the European Union is available on the Internet.
It can be accessed through the Europa server (http://europa.eu.int)
Cataloguing data can be found at the end of this publication
Luxembourg: Office for Official Publications of the European Communities, 1997
ISBN 92-827-8989-6
© European Communities, 1997
Reproduction is authorized, provided the source is acknowledged
Printed in Luxembourg FOREWORD
To discourse on thorium these days when uranium is cheap and plentiful may be
taken as a provocation. Besides, thorium may be considered as a "parent pauvre"
compared to uranium, as it has no readily fissile component, and needs a "spark"
to produce energy.
In a sense, it is a provocation indeed, which has come out from simple
considerations :
the vast amount of work done on thorium in the past thirty years must be
preserved for the coming generations,
the ideas revived by Carlo Rubbia and others, that the thorium cycle may
present advantages over uranium from the point of view of waste
management.
Besides, other parameters should be kept in mind :
the finite uranium reserves in the world which can be usefully
complemented by thorium : the case of India, with huge energy needs and
relatively small uranium reserves, but rich in thorium, is exemplary;
the refractory properties and neutronic stability of thorium oxide may be
useful for certain types of reactors;
by-product U-233 is a very versatile fissile material which compares
favourably with U-235 or Pu-239 in many reactor applications.
In this study, we have tried to summarise in a simple way, the state of the art for
thorium. It is difficult to give a true account of the huge sum of research work
and accomplishments in the field, and we beg for understanding of the critical
reader for any unintentional oversight.
We hope, however, to have contributed to a renewed comprehension of this
interesting fuel cycle, which could play an important role in our energy future,
together with uranium.
I wish to thank the European Commission for sponsoring this study, and also all
who, in the past and present, have helped me in this work, as recalled further on.
Ill ACKNOWLEDGEMENTS
I am particularly indebted for the redaction of this Report to a number of friends,
former colleagues and specialists whom I wish to recall here. Those whom I may
have forgotten will, I hope, forgive me :
Dr. S. FINZI, former Director at the Commission, for his enlightened
cooperation and useful comments,
Sri A.N. PRASAD, Sri A. KAKODKAR of BARC, and their colleagues,
especially Mrs. Kamala BALAKRISHNAN,
Sri P. RODRIGUEZ of IGCAR, and his colleagues,
for their kind reception and useful information on thorium fuel cycle in India,
MM. R.E. BROOKSBANK and E. SHANK, old ORNL friends, and
R. CONRAD, ORNL,
Drs. R. BASCHWITZ and P.E. JUHN, Directors at IAEA,
Dr. A. RADKOVSKY, Professor at the University of Tel Aviv,
Drs. D. Mc LEAN and P. BOCZAR of AECL, Canada,
Dr. D. TSOURIKOV, of the Kurchatov Institute,
Prof. H. VAN DAM, Delft University of Technology,
Dr. E. MERZ, formerly at KFA, Jülich,
Dr. A. LECOCQ, French CEA,
Drs. J. VAN GEEL, H.J. MATZKE, J. MAGILL, of the EC-JRC Institut
fur Transurane, Karlsruhe,
G. SANCHEZ, of the European Parliament,
for their kind cooperation and advice upon my queries,
Profs. I. KTMURA and K. FURUKAWA, Japan, for the respect I owe to
their work, Profs C. RUBBIA and CD. BOWMAN, who contributed to inspire this
work;
Drs. W. BALZ, R. SIMON, from EC DG XII and especially Dr.
O. GREMM, Mr. G COTTONE AND Mr. R. BISCI, who carefully
supervised this work.
The reviewers of this Report, Mrs. Sue E. ION, P.D. WILSON, K. AIS WORTH
of BNFL, L. PATARIN of Cogema, M. SALVATORES of CEA,
E. TEUCHERT formerly with KFA, Jülich, G. SCHLOSSER of Siemens,
L. KOCH, TUI, who took the pains to make useful remarks, most of which have
been included in this last edition. They will forgive me, I hope, if (rarely) I was
not fully of their opinion.
All of those, cited in the References, who in their publications contributed to the
knowledge on the thorium fuel cycle, that I felt worthwhile to quote.
Sometimes, for simplicity and clearness' sake, I have taken the liberty to
reproduce excerpts, tables and charts from those, feeling that I could do so in a
document which is not intended for commercial use, but as a contribution to an
important scientific sector in the nuclear fuel cycle.
Thanks to my wife, this Report came into readable form.
I will appreciate further comments to this work, being conscious that there are,
most probably, unwanted errors or omissions.
Michel Lung
VI TABLE OF CONTENTS
Page
Foreword m
Acknowledgements V
Introduction 1
1. Executive Summary 3
2. Thorium and concerned isotopes : nuclear reactors and
possible applications
2.1. Thorium radioactive decay 13
2.2. Neutronic reactions 20
2.3. Theoretical applications to nuclear reactors 4
2.4. Production of long-lived actinides5
3. Thorium-based reactors, mixed cycles, experience gained
3.1. U-233 breeding 54
3.2. Using thorium in power reactors,
Introductory remarks
3.3. Application to High Temperature Reactors 62
3.4. Heavy Water Moderated Reactors 88
3.5. Light Water Reactors 9
3.6. Once-through Cycles9
3.7. FastReactors
3.8. Advanced or special concepts 103
3.9. Recent developments in advanced mixed-cycles
reactor studies 112
3.10. The long-term: accelerator-driven reactors 116
4. The Accelerator-driven Subcriticai Systems based on the Thorium
Fuel Cycle
4.1. General remarks 119
4.2. The Energy Amplifier 126
4.3. Isotopie incineration by actinides transmutation 134
4.4. Isotopes production via an accelerator-driven
subcriticai reactor 142
4.5. Tentative evaluation of the hybrid systems I4
VII 5. Thorium resources, thorium compound extraction and preparation
5.1. Thorium resources 148
5.2. Nature of Thorium resources 151
5.3.m compounds extraction and preparation 154
6. Thorium-based fuel element fabrication
6.1. Introduction 165
6.2. Thorium metal fuel elements
6.3.m oxide fuels
6.4. Mixed fuels 176
6.5. Fabrication of U-23 3 MTR-type fuel elements 220
7. Reprocessing of the Thorium-Base Irradiated Fuels
and Waste Management
7.1. Introduction 223
7.2. The "Head-End" operations4
7.3. Separation and purification operations 242
7.4. Waste treatment 260
7.5. The "dry" processes
7.6. Concluding remarks to this chapter
8. Overview of the national/international programmes
for the thorium fuel cycle
8.1. Historical reminder (beginning until 1975-1980) 264
8.2. Difficulties, the oil shock, focusing on U-LWRs 276
8.3. The end of the Thorium programmes, keeping
technological awareness (1980-1990) 277
8.4. Renewed theoretical interest (1990-)8
8.5. Conclusion 282
9. Concluding remarks
9.1 Observations5
9.2 General considerations6
9.3 Recommendations for further developments 2s7
10. References
10.1. References to chapters 2 and 3 : Thorium and
concerned isotopes, reactor applications 288
10.2.s to the accelerator-driven subcriticai systems 290
10.3. References to thorium resources, mining, metallurgy
and fuel elements fabrication 292
10.4.s to reprocessing, waste management5
10.5. References to national/international programmes 297
10.6. Other references8
Vili