Successful sample-taking trip to Greenland for Posiva researchers
“Sample-taking went as well as could be hoped.” Posiva’s hydrogeologist Anne Lehtinen and chemist Tiina Lamminmäki recently spent a week in Greenland taking water and gas samples from a borehole which reaches below the glacier.
“This is a significant study, since we will receive more information about the effects of the ice sheet in groundwater in ice age conditions. We will also get more detailed information about the effects of the glacier in the final disposal depth, more than 400 metre’s down.
Knowledge of groundwater composition is
significant for the final disposal system, since the materials of the final
disposal canister are copper and cast iron and the chemical composition of
water affects, for example, the corrosion of copper. From
samples taken at different depths, it is possible to surmise how large a
portion of the groundwater near the glacier is glacier's meltwater.
“Next we will start drawing up the final report of our studies in Greenland. This will continue for the next year,” says Lehtinen, who has returned to Finland and Olkiluoto.
Water samples from various levels, in other words packered-off sections at 350–645 metres – the highest (U), the middle (M) and the lowest (L) packered-off section. The lowest packered-off section has been purified and there is no longer any green tracer colour used in boring left in the water.
A cooperation network comprising various companies and research institutes conducts Greenland Analogue Project studies. From right to left, Anne Lehtinen and Tiina Lamminmäki (Posiva), Emily Henkemans (University of Waterloo) and Laura Kennell (NWMO).
Greenland Analogue Project (GAP)
A key question in Posiva's research and development work is how an ice age would affect the final disposal facility for spent nuclear fuel because an ice age is expected in Finland during the next 100,000 years.
In cooperation with Sweden-based SKB and the Canada-based NWMO, Posiva is conducting a study in Greenland to obtain more information on ice age conditions. The impact of glacier meltwater deep in the rock is the main focus of the study. Numerous research institutes also participate in the research project.