Trial storage of high-level waste cylinders in the Asse II salt mine. Final report

Directorate-General For Research And Innovation

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• Publié par: DIRECTORATE-GENERAL-FOR-RESEARCH-AND-INNOVATION
• Nombre de lectures: 16
• Langue: English
• Poids de l'ouvrage: 5 Mo

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Commission of the European Communities
nuclear scienc
antf ichnolc
Trial storage
of high-level waste cylinders
in the Asse II salt mine
&£ίΣ*
EUR 8797 EN Commission of the European Communities
nuclear science
and technology
Trial storage
of high-level waste cylinders
in the Asse II salt mine
Entwicklungsgemeinschaft Tief lagerung
Gesellschaft für Strahlen- und
Umweltforschung mbH München
Ingolstädter Landstraße, 1
D-8042 München-Neuherberg
Kernforschungszentrum
D-7500 Karlsruhe 1
Final report 1977/78
Research contract No 015-76-1-WAS-D in the scope
of the indirect action programme 1976/77 and partly 1978
of the European Atomic Energy Community
'Management and storage of radioactive waste'
Action No 7 : 'Disposal of radioactive waste in geological formations'
Directorate-General
Science, Research and Development
1984 EUR 8797 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Information Market and Innovation
Bâtiment Jean Monnet
LUXEMBOURG
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting on
behalf of then is responsible for the use which might be made of the
following information
Cataloguing data can be found at the end of this publication
Luxembourg, Office for Official Publications of the European Communities, 1984
ISBN 92-825-4514-8 Catalogue number:
© ECSC-EEC-EAEC, Brussels · Luxembourg, 1984
Printed in Luxembourg Preface
The following report covers the contract period 1976/77
as well as some of the tasks carried out during the
prolongated term in 1978.
+) see table of contents
III Table of contents
Page No
1.0 Laboratory- 1
and in situ-Experiments
1.1 Experiments on Temperature Distribution and 1
Measurements of Convergence in Cased and
Uncased Boreholes
1.1.1 Simulation Experiment in the Older Halite - 2 +)
Uncased Borehole
1.1.2n Experiments in Cased Boreholes 12 +)
1.1.3 Development of a Standard Probe for Systematic 23 +)
Studies of Thermally induced Borehole
Convergence
1.1.4 Convergence Measurement of Galleries and 28
Boreholes in Connection with Temperature
Experiments already Carried Out or to
be Carried Out
1.1.5 Determination of Absolute Stress 33
1.2 Laboratory Experiments for the Determination 42 +)
of Rheological Properties of Asse Rock Salt
at Elevated Temperatures and after Irradiation
1.3 Experiments on the Corrosion of Materials 52 +)
for Borehole Casings and for Waste Packaging
Canister in Salt
1.4 Migration and Release of Enclosed Brine 64 +)
Droplets in Older Halite
1.5 Investigations on Migration in Brines 80 Page No,
2.0 Computer Programmes 86
2.1 Improvement of Existing Computer Programmes 87
for the Calculation of Temperatures in the
Glass and in the Salt for Individual Storage
Hole Arrangements as well as in the Salt
Formation outside the Burial Area and in the
Overlying Formations
2.2 Development of Computer Codes for the 115
Calculation of the Stability of Single
Pillars and the whole Disposal Field
with Consideration of the Effects of
Elevated Temperatures
3.0 Technical Systems and 139
Equipment
3.1 Development of a Shielding Container for 140 +)
Highly Radioactive Glass Blocks
3.2 Technical Facilities and Systems, 16-1 +)
Development Purchasing of the other
Technicals and Systems for
Transport, Storage and Recovery of
High Level Glass Cylinders
3.3 Technical Facilities and Systems, 182
Proposition, Development, Purchasing
and Assembly of Monitoring and
Measuring Instruments
4.0 Summary 185
Coordinator of the Programme: H. G i e s
+
Contract time and report period under review included
some tasks in 1978 as well.
VI Abstract
The initial contract period stood chiefly in the sign
of trial planning, examination of the concepts as well
as of the procurement and testing of trial components.
With regard to the in-situ tests for the liberation
and migration of brine, the testing devices were examined
successfully for their functional efficiency in a pilot
test. Laboratory examinations carried out parallel to
this, showed a stepwise liberation of the water contents
in halite in dependence on the temperature. The amount
of brine liberated stood in good agreement with the in-
situ results.
For the quantitative examination of the borehole conver­
gence in heated halite, a voluminous examination of compo­
nents was begun, which has already been partially concluded,
This also includes the conception and construction of a
new type of heater, procurement of a test autoclave, data
processing plant as well as the development of a standard
probe for borehole convergence in its mechanical part.
A temperature test for borehole convergence resulted in
definite convergence rates for the first time. Simultaneous­
ly no influence was registered in the stability of the
surrounding rocks.
For the realization of an integrated major experiment,
temperature test field IV was mined on the 750 m level
of the Asse Salt Mine and heater- as well as measurement
drillings were carried out.
The determination of absolute stress in rocks is presently
still struggling both with considerable methodical and
apparative difficulties.
Extensive rheological examinations are concentrated parti­
cularly on the halite and secondly on the Carnallite. They
VII are chiefly based on uni- and multiaxial pressure tests.
The works dealing with the investigation of processes in
brines as well as the corrosion of container materials could
be started only very hesitantly for different reasons. The
trial concepts finally drawn up were being worked on at the
end of the report period, however.
The development of computer programmes to examine the heat
generation in wastes as well as in salt, accompanying the
temperature tests in part, and subdivided according to the
conditions of near field and far field, made good progress.
In comparison, the programme development of computer codes
for the stability behaviour of rocks is still at a relatively
early stage, this being due to the fact that it has to build
up on the results of heat generation.
The works for the development of a transport container with
a shielding combination are at a very advanced stage. An
integrated disposal- and retrieval system was developed,
tested and successfully demonstrated. A monitoring system
in the mine has also been developed in its essential parts.
VIII