Workreport 2008-58



ONKALO EDZ-Measurements Using Ground Penetrating Radar (GPR) Method


Silvast, M. & Wiljanen, B.



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This report presents pilot project results from various Ground Penetrating Radar (GPR) tests performed on bedrock in ONKALO, the research tunnel system being built for the final disposal of spent nuclear fuel. In recent years the GPR technology for structure inspection has improved to faster systems and higher frequencies. Processing and interpretation software has been developed for better visualization of processed data. GPR is a powerful non-destructive testing method with major advantages such as fast measurement speed and continuous survey lines.

The purpose of the tests was to determine the capacity of GPR in identifying the Excavation Damaged or Disturbed Zone (EDZ). Topics included comparison of different types of GPR systems and antennas in select locations in the tunnel system and data presentation. High quality GPR data was obtained from all systems that were used on surfaces without concrete or steel reinforcement. Data processed using Geo Doctor software, which enables integrated analysis of available datasets on a single screen, provided promising results.


Ground Penetrating Radar (GPR), Excavation Damaged or Disturbed Zone (EDZ), Electric Conductivity, Dielectric Value, Geophysics


ONKALO EDZ-Measurements Using Ground Penetrating Radar (GPR) Method (pdf) (6.1 MB)


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