Geologia

EDZ in Crystalline Rock and Effect on the
Migration in a KBS-3 Type Repository

Jorma Autio, Thomas Hjerpe, Saanio&Riekkola Oy
Maikki Siitari-Kauppi, Laboratory of Radiochemistry,
University ofHelsinki
Acknowledgements: Posiva Oy and Swedish Nuclear Fuel and
Acknowledgements:
Waste Management
Waste
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KBS-3 type repository in Finland
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The site is at Olkiluoto in South-West Finland (s. 2004)
The main alternative is KBS-3V
An alternative KBS-3H is also studied
Several Plugging and Backfilling alternatives
Hard graniticrock at a depth of about 450 m

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Excavation damage in a KBS-3
repository
1. Tunnel D&B EDZ
2. Depositionhole EDZ
3. Stress induced
damageCLUSTER-EDZ-Conference-031103-Luxembourgh

EDZ & PA - requirement
EDZ shall not become a major conductor of
groundwater
Therefore objectives of the backfill and sealings:
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To prevent the EDZaround the tunnels and access
routes from becoming major conductors of
groundwater
To prevent growth of EDZ if necessary

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What have we done ?
Studyof excavation damage in samples
taken from:
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Experimental depositionholes at Olkiluoto
Experimental depositionholes at Äspö
TBM tunnel at Äspö
Olkiluoto Research Tunnel excavatedby drill and blast
ZEDEX-tunnel at Äspö and it’s extension excavated by
drill and blast

Evaluation of significance of EDZ
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Input from Full scaledeposition holes at the Äspö
HRL & Research Tunnel at Olkiluoto
Rotary crushing and vacuum flushing technique.

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Surface of the experimental
depositionhole at Äspö HRL.

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EDZ caused by TBM and SBM
Studied using
14C-PMMA
method and
SEM
Photograph
(left) and
corresponding
autoradiograph
(right) of...