Greenland Analogue Project – Investigation of the hydrogeological ...

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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)

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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)

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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

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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

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Lehtinen Anne 11

11

19 June 2013


DH-GAP01 – The talik hole

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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

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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.

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18


DH-GAP04

Permafrost

depth ca 400m

depth

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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.

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22


Thank You !

19 June 2013 Lehtinen Anne 23

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