Euradwaste '08 - EU Bookshop - Europa

Contact stress [MPa]
3.5
3
2.5
2
1.5
1
0.5
0
19 Oct 08
29 Oct 08
08 Nov 08
18 Nov 08
28 Nov 08
HPC 3
Date
08 Dec 08
18 Dec 08
433
28 Dec 08
Figure 6: Contact stress and temperature measurement
4. Conclusion
The performance of physical models built in a real “in situ” environment provides knowledge
which cannot be obtained through any other form of experimental research. The models, however,
must be designed, constructed and operated to a high professional level. In the case of the “Lining
stability under thermal load” experiment, this has been accomplished.
The laboratory experiment served for gaining the knowledge and experience necessary for the construction
of a follow-up experiment in a genuine underground environment. The instrumentation
and the REVEL heating system have been thoroughly tested. The measured values of deformation
and displacement caused by thermal loading are particularly well applicable to the solution of the
long-term stability of the lining.
The knowledge obtained was used to very good effect during the somewhat demanding construction
of the “in situ” experiment. The measurement of all the relevant parameters with an interval of once
per 10 minutes allows the monitoring of the stress state deformation response of the lining and the
rock mass to gradually increasing thermal loading. The high stress measured both within the lining
and on contact with the rock mass before maximum thermal loading was reached justifies the decision
to construct the lining of the disposal tunnel of high-strength concrete.
The performance of these physical models will continue at least until the end of 2010 which will
allow the gathering of further important results applicable to the safe design of the lining of disposal
tunnels.
5. Acknowledgements
The “Thermal Impact on the Damaged Zone Around a Radioactive Waste Disposal (Vessel) in Clay
Host Rocks (TIMODAZ)” project is co-funded by the European Commission and forms part of the
sixth EURATOM research and training Framework Programme on nuclear energy (2002-2006)
under contract No. FI6W-36449.
References
[1] Pacovský J. (2007). The Use of the Mock-up-CZ Physical Model in the Design of Engineered
Barriers. WITpress – Management of Natural Resources, Sustainable Development and Ecological
Hazards, ISBN 13: 978-1-84564-048-4.
[2] Pacovský J., Zapletal, L., and Svoboda, J.(2007). Development of Saturation in a Bentonite
T 3
07 Jan 09
40
35
30
25
20
15
10
5
Temperature [ o C]