Nuclear power stations produce very little emissions when in operation, but when they are decommissioned, the mishandling of nuclear waste can have lasting consequences for human health and the environment. Usually, waste is kept in temporary facilities overground, but Finland has decided to bury all of its nuclear waste.
A tiny island off the west coast of Finland, named Olkiluoto, has been selected to become the burial site for the Scandinavian country's radioactive material. A series of tunnels are being excavated more than 420 meters (1,380 feet) below ground, and it will cost the country $4 billion.
It will accommodate 5,000 tonnes (5,500 tons) of material from 2020 until the 2120s, when it will be sealed once and for all. This project took many years to begin, as scientists looked for the most suitable bedrock for the facility. Currently, it stretches for about 5 kilometers (3 miles), and it will eventually become a labyrinth of 42 kilometers (26 miles) worth of tunnels.
"This has required all sorts of new know-how," said Ismo Aaltonen, chief geologist at nuclear waste manager Posiva, which got the green light to develop the site last year, according to the Associated France Press.
The spent radioactive material will be placed in iron casts that will then be sealed into thick copper canisters and surrounded by clay (to prevent movements and water from seeping in). The canisters will then be lowered into the tunnels. Although it's thought the material will be safe in a few hundred years, scientists are playing it safe by aiming for 100,000 years of storage.
Eventually, the tunnels will be sealed with ferro-concrete plugs to guarantee that the site will stay completely inaccessible. Posiva is trying to consider what is the best approach to discourage people in the future from digging in the area.
"It is still being discussed if the place should be marked with warning signs," Aaltonen added. "There are examples like in Egypt, where a curse was to fall upon the person who passed a certain door and of course, people just entered there."
Olkiluoto already houses two nuclear reactors with a third one under construction, and local residents welcomed the plans for a burial ground.
"Personally, I believe that when [the waste] is placed deep down there with care and expertise, it is better than how it is now around the world – placed wherever," said local vegetable farmer Timo Rauvola.