A summer internship spent studying the bedrock
Joona Suhonen, 25, a geology student at the University of Helsinki, is now studying the Olkiluoto bedrock as a summer intern for the second time. What particularly drew Mr Suhonen to apply for a position in Olkiluoto was the unique final disposal of used nuclear fuel.
- This is not happening anywhere else yet, so I am glad to be a part of it. As a geologist, I also find the tunnels intriguing, and Olkiluoto does have social significance, Mr Suhonen says, listing reasons that made him apply to Olkiluoto for a second time.
Most commonly, you can find him near Posiva’s disposal facility at the research hall that studies drill core samples taken from ONKALO.
Versatile research
Joona Suhonen started at Olkiluoto in mid-May, and he has enjoyed his time, which seems to have flown by. He particularly likes the variety of the work.
In practice, he often starts his day by completing various routine tasks on data systems or doing things like cleaning the seismic stations. Then, the rest of the day is spent with drill core logging and working on core samples.
Drill core logging means that core samples taken from the bedrock by drilling are analysed, and information such as rock type, joint count and fissility are recorded. Furthermore, Mr Suhonen orients the samples. He uses a tape measure, for example, when working.
- It has perhaps been a little surprising how long it takes to compile and process the drill core material, Mr Suhonen says.
In addition, the drill core holes undergo geophysical and chemical measurements, among other things. This information can then be used for determining whether the specific location is suitable for making an actual deposition hole in which a spent fuel final disposal canister can be placed in the future.
A new kind of understanding – and rocks
Joona Suhonen comes from the city of Kerava, and he is starting his fifth year of studying geology at the University of Helsinki. He has not fully decided what he will do in the future.
It will be a researcher position or something to do with research, Mr Suhonen says, describing his future job, but he does not entirely rule out working at Olkiluoto either. The place has at least taught him a lot. In addition to learning how to do bedrock mapping and drill core logging, Olkiluoto has provided Joona Suhonen with a new kind of understanding of the large elements in the bedrock.
- Inside a tunnel you can actually see how a weakness zone can pass through the bedrock, Mr Suhonen explains, with excitement.
- Rocks, Joona Suhonen immediately replies when asked what is best about his work. This is his second summer in Rauma, and his tips for visitors include checking out Old Rauma and the Rauma Lace Week festival.
- This is one of the only workplaces where you get to think about really long time spans, Joona Suhonen explains while looking at drill core samples taken from Finland’s 1.8–1.9 billion years old bedrock.
The text was written by Veikka Jänkävaara who, similarly, is doing his second summer internship at Olkiluoto. Veikka is a physics student at the University of Turku. He works in Corporate Communications and he is the other instructor for the children’s science camps.
Photos by Jessi-Julia Salonen