New trends in the separation of 137Cs, 90Sr and transplutonium elements from radioactive HLW by borane and heteroborane anions

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European Commission
New trends in the separation of 137Cs, 90Sr and
transplutonium elements from radioactive
HLW by borane and heteroborane anions
Report
EUR 182 EUROPEAN COMMISSION
Edith CRESSON, Member of the Commission
responsible for research, innovation, education, training and youth
DG XII/F.5 — RTD programme 'Management and storage of radioactive
waste 1990-94' and INCO-Copernicus programme
Contact: Mr G. A. Cottone
Address: European Commission, rue de la Loi 200 (MO 75 5/43),
B-1049 Bruxelles — Tel. (32-2) 29-51589; fax (32-2) 29-54991 European Commission
nuclear science
and technology
New trends in the separation of 137Cs, 90Sr and
transplutonium elements from radioactive
HLW by borane and heteroborane anions
F. Teixidorf), B. Casensky(2), J. F. Dozol(3), S. Hermánek(4), H. Mongeot(5), J. Rais(6)
(') Institut de Ciencia de Materials de Barcelona, Barcelona
Spain
O Katchem Ltd, Prague
Czech Republic
(3) CEA - Cadarache
France
(4) Institute of Inorganic Chemistry, Rez near Prague
Czech Republic
H Université Claude - Bernard, Lyon I
France
f5) Nuclear Research Institute, Rez near Prague
Czech Republic
Contract No CIPA-CT93-0133
Final report
Work performed as part of the EC INCO-Copernicus programme
Directorate-General
Science, Research and Development
1998 EUR 18217 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, 1998
ISBN 92-828-3359-3
© European Communities, 1998
Reproduction is authorised provided the source is acknowledged.
Printed in Luxembourg
PRINTED ON WHITE CHLORINE-FREE PAPER SUMMARY
The evaporation and/or precipitation of liquid radioactive MLW produce concentrates and
residues, which have to be disposed of in geological repositories due to the presence of long-
lived radionuclides (^Sr, 137Cs and actinides). The volume of this waste can be strongly
reduced, if the long-lived radionuclides are selectively separated from the concentrates and
residues. The large part of these wastes would be directed to a subsurface repository, while the
very small part containing the long-lived radionuclides would be disposed of in geological
formations after conditioning.
Extractante based on ß-Co-O^^BcHn^]' (COSAN), [H3N-B12Hn]", [H3N- Bi0H9]' and
[CBnH12]" have been synthesized by the Institute of Inorganic Chemistry at Rez (Prague), the
Materials Science Institute of Barcelona, and the University Claude Bernard of Lyon and tested
by the Commissariat of Atomic Energy (CEA) at Cadarache and the Nuclear Reserach Institute
at Rez. Substitution of good performance non-environmentally friendly nitrobenzene by
mixtures of more acceptable solvents has been successfully achieved mainly by arene B-
substituted COSANs. Adequate use of solubilizers and synergist compounds has been
performed for selectivity improvement. Monoether chains on COSAN carbon seem to be
adequate for actinides extraction. Macrocyclic derivatives of ^N-B^Hn]" seem adequate for
90
Sr sequestering.
COLLABORA TORS INVOL VED IN THE PROJECT
* Institute of Inorganic Chemistry, Rez: B. Grüner, S. Hermánele, J. Plesek.
* Institut de Ciencia de Materials de Barcelona: J. Bertran, S. Gomez, F. Teixidor, C. Viñas.
* Université Claude-Bertrand, Lyon Ι: Β. Bonnetot, Β. Grüner, Η. Mongeot, D. Naoufal.
* Nuclear Research Institute, Rez: J. Rais, P. Selucky, Ν. V. Sistková.
* CEA Cadarache: J.F. Dozol, Η. Rouquette.
* Katchem Ltd.: B. Casensky
III CONTENTS III
SUMMARY
1. INTRODUCTION 1
2. SYNTHESIS OF DERIVATIVES OF C2B10 AND C2B9 CONTAINING
AROMATIC FRAGMENTS (Institute of Inorganic Chemistry, Rez) 2
2.1. Introduction 2
2.2. Tasks under the present project 4
2.3. General syntheses and proposed mechanisms 5
2.4. Examples of synthetic procedures 11
2.5. Isolation, identification and structural characterization 12
2.6. General Properties of substituted COSAN 2
2.7. New solvent systems for extraction of inorganic ions from water solutions 24
2.8. Conclusions and recommended general strategy6
3. SYNTHESIS OF DERIVATIVES OF C2B10 AND C2B9 CONTAINING
POLYETHER AND AROMATIC FRAGMENTS (Institut de Ciencia de
Materials, Barcelona) 28
3.1. Introduction
3.2. Results and Discussion9
3.3. Experimental 3 9
4. SYNTHESIS OF DERIVATIVES OF B10 AND B12 (Université Claude-
Bernard, Lyon) 54
4.1. Introduction
4.2. Results and Discussion7
4.3. Conclusion 85. EXTRACTION TESTS ON THE SYNTHESIZED DERIVATIVES (Nuri
Rez) 86
5.1. Introduction
5.2. Experimental
5.3.l Methods7
5.4. Results and discussion8
5.5. Conclusions and future prospects 99
6. EXTRACTION AND TRANSPORT EXPERIMENTS ON THE
SYNTHESIZED DERIVATIVES (C.EA. Cadarache) 121
6.1. Introduction 121
6.2. Determination of distribution coefficients 122
6.3. Supported liquid membranes 123
6.4. Transport model 124
6.5. Screening of extractants 125
128 6.6. Stability of S.L.M. containing dicarbollides
6.7. Conclusion 128
CONCLUSION 141
REFERENCES 144
ANNEX 1 : PREPARATION OF BASIC STARTING BORANE
COMPOUNDS (Katchem Ltd. Praha) 149
ANNEX 2 : CHEMICALS GRAPHICAL DESCRIPTION 158
ANNEX 3 : PUBLICATIONS ISSUED FROM THIS PROJECT 172
ANNEX 4 : PATENTS 175
VI 1. INTRODUCTION
Nuclear waste reprocessing operations produce both high level and medium level
activity liquid wastes (HLW/MLW). The major nuclides in these radioactive wastes are those
with long half-lives, mainly β/γ emitters or α emitters such as transuranium elements, that is
why great efforts have been devoted throughout the world to propose harmless storage of
these wastes. The burial of vitrified reprocessed HLWs (containing fission products and α
emitters) has been considered as the safest method for their permanent disposal whereas
MLWs are treated by evaporation in order to concentrate their radioactivity into the smallest
possible volume. This treatment nevertheless leads to large volumes of concentrates
composed of active and inactive salts (mainly: NaN03, 4 mol.L"1 and HNO3, 1 mol.L"1 as the
matrix). The greater part of these concentrates has to be disposed off in geological formations
after embedding due to their activity in long-lived radionuclides (actinides, strontium, cesium,
etc.). Therefore it would be desirable to remove these long-lived radionuclides from the
contaminated liquid wastes before embedding. These would allow a large part of these wastes
to be directed to a subsurface repository, and a very small part containing most of the long-
lived radionuclides to be disposed off, after conditioning, in geological formation.
Dicarbollide process of extraction of l37Cs and 90Sr was proposed at former Czechoslovakia
by the workers of Inorganic Chemistry Institute, Czech Academy of Sciences, and Nuclear
Research Institute, Rez. Afterwards it was developed into stage of laboratory hot scale and
even to 6 months successful plant scale in collaboration with Radium Institute of St.
Petersburg, Russia. In Russia a plant based on dicarbollide technology was launched in
autumn of 1996. Presently there is cooperative research on this subject between USA and
Russia but details in the open literature are scarce. The best known extractants based on the
dicarbollide technology are [3-Co-(l,2-C?B9Hn)2] and its hexachloro protected analogue. A
most efficient transfer of Cs(I) and Sr(II) cations from water into water-immiscible solvents
was achieved with nitrobenzene which is, however, not environmentally acceptable. The task
of this investigation was to put the basis for actinide separation by using [3-Co-(l,2-
C2B9Hn)2] " and to preserve all positive properties of [3-Co-(l,2-C2B9Hu)2] " type molecules
in Cs(I) and Sr(IT) extraction while allowing to substitute nitrobenzene by ecological solvent
systems. Throughout the text the chemicals corresponding to the abbreviations utilized can be
found at ANNEX 2. SYNTHESIS OF DERIVATIVES OF C2B10 AND C2B9 CONTAINING
AROMATIC FRAGMENTS (Institute of Inorganic Chemistry, Rez)
2.1. Introduction
The parent species of this class of compounds, [3-Co-(l,2-C2B9Hn)2]" (1) (FIGURE 1),
see below, has been revealed as one of the archetypes of all future metallaboranes by M. F.
Hawthorne, U.S.A. and has been first reported in 1965.'
with emphasized hydrophobic "fur" numbering of the skeletal atoms;
of terminal hydrogens terminal hydrogens omitted for
clarity
FIGURE 1. The [3-Co-(l,2-C2B9Hn)2]" ion.