Greenland Analogue Project – Investigation of the hydrogeological ...

The Greenland Analogue Project –
Investigation of the hydrogeological
challenges during glaciation
Cooperation project between Posiva, SKB and NWMO
Anne Lehtinen 1 , Lillemor Claesson Liljedahl 2 & Timo Ruskeeniemi 3
Radioactive Waste Disposal workshop May 30, 2013
1
Posiva Oy, Finland
2
Svensk kärnbränslehantering 1 AB
3
Geological survey of Finland

Outline
• GAP project and its aims
• Subproject A: Ice sheet hydrology
• Subproject B: Subglacial ice sheet hydrology
• Subproject C: Bedrock hydrogeochemistry and
hydrogeology
19 June 2013 Lehtinen Anne 2

Background
• GAP was initiated by SKB and preliminary field
reconnaisance was made in 2005
• In 2007 Posiva started the discussions with SKB and
in 2008 preliminary field work e.g. geological
mapping was done
• In 2008 NWMO joined the collaboration
• In 2009 the GAP project was launched
3

Motivation
• Finnish and Swedish safety assessments indicate that periods of
glacial conditions provide highest doses and risks
• ’We have a poor understanding, and therefore large uncertainties,
concerning hydrological processes related to glacial conditions’
• In the comments from authorities on the SKB and Posiva safety
assessments:
• Large hydrological uncertanties for glacial cases
• Suggest using analogues in order to increase knowledge and reduce
uncertainties
• In other countries where ice sheets are expected in the future, same
questions need to be answered in e.g. Canada and UK
• Results are important for the assessment of long-term safety (100 kyrs)
19 June 2013 Lehtinen Anne 4

Example of processes that can affect
repository safety during the glaciations
• Ground water oxygen concentration
(canister corrosion)
• Groundwater salinity
(buffer stability)
• Glacial erosion
(influences e.g. permafrost depth)
• Glacially induced earthquakes
(canister failure)
• Maximum pressure at repository depth
(canister failure)
• Maximum permafrost depth
(canister failure, buffer function)
19 June 2013 Lehtinen Anne 5

GAP project (2009-2012)
• Co-ordinating and funding organizations
• SKB (Sweden), Posiva (Finland) and NWMO (Canada)
• Project manager: Lillemor Claesson Liljedahl (SKB), and
deputy project manager:Anne Lehtinen (Posiva)
• Research partners
• GEUS, GTK
• Universities: UK/Aberystwyth, Bristol, Edinburgh, Swansea;
USA/ Montana, Wyoming, Colorado, Indiana, Princeton,
Washington; Canada/Waterloo, Toronto;
Sweden/Stockholm, Uppsala
• Geosigma AB, Lawrence Berkeley National Laboratory,
Pöyry etc.
19 June 2013 Lehtinen Anne 6

Overall aims and project questions
• Observations of how an ice sheet forms groundwater; (incl. hydraulic
gradients at ice sheet bed, driving groundwater flow)
• Observations of whether glacial meltwater may penetrate crystalline
bedrock down to repository depth (500-700 m);
• Observations of chemical composition of groundwater if/when it
reaches repository depth (e.g. oxygen content and salinity);
• Use a real world example of these processes, not only modelling
results. Show that we have process understanding
• The project will provide us with an integrated view on ice sheet
hydrology and groundwater flow/chemistry
19 June 2013 Lehtinen Anne 7

SPA
Sub-project A (sub-project manager: Alun Hubbard)
Indirect studies of hydrological system at ice sheet bed
and groundwater formation. Radar/GPS/AWS
SPB
Sub-project B (sub-project manager: Joel Harper)
Direct studies of hydrological system at ice sheet bed. Drilling
through ice sheet. Measurements of pressure.
SPC
Sub-project C (sub-project manager: Timo Ruskeeniemi)
Groundwater chemistry and flow. Deep bedrock drilling
close to ice margin and talik investigations

Sub-project C
Research in permafrost conditions
9

Project area
19 June 2013 Lehtinen Anne 10

Lehtinen Anne 11
11
19 June 2013

DH-GAP01 – The talik hole
19 June 2013 Lehtinen Anne 12

DH-GAP01
- 0 m
- 17 m
Talik Lake
Temperature profile (DTS)
down to 150 m/130 mbgs
Inflatable packer: 150 m/130 mbgs
Sample reservoir + Aquatroll at the
bottom (12 m): 162 m/140 mbgs
Sampling section of 71 m
- 200 m EOH: 221 m/191 mbgs
203.80 m
K: 2-5 10 -8 m/s
T: 10 -6 m 2 /s
19 June 2013 Lehtinen Anne
13

Length [m]
DH-GAP01, Fractures/m
0 5 10 15 20 25
0
50
100
150
200
250
19 June 2013
14

Temperature profiles in DH-GAP01 (left) and DH-GAP03
(right) calculated for vertical depths.
Note that the vertical depth extension is not the same in the two figures.
19 June 2013 Lehtinen Anne 15

19 June 2013 Lehtinen Anne 16

19 June 2013 Lehtinen Anne 17

19 June Lehtinen 2013 Anne
18

DH-GAP04
Permafrost
depth ca 400m
depth
19 June 2013 Lehtinen Anne 19

19 June 2013 Lehtinen Anne 20

GAP project today
• DH-GAP04 sampling
• GAP Data, processes and conceptual understanding report
(Data report)
• The report will present the objectives of the research and
investigations, present the different data sets that have been
collected throughout the project, and describe the
conceptual understandings developed for each of the SPs.
The report will describe to what extent the collected data
supports these conceptual understandings.
• The GAP Final report will be a synthesis report, but will also in
part be a summary report which summarizes and integrates the
conceptual understandings presented in the Data Report, and
also summarizes the key data/understanding gained during
GAP, specially from the point of nuclear waste management.
19 June 2013 Lehtinen Anne 21

19 June 2013 Lehtinen Anne
22

Thank You !
19 June 2013 Lehtinen Anne 23