Many countries want to abolish nuclear energy but Finland is ready to coexist with it. After new nuclear power plants come online this year, nuclear power will account for more than 40% of Finland's total electricity. Finland is still lobbying the EU to view nuclear as sustainable because there are ways to deal with nuclear waste by burying it in the ground. Finnish radioactive waste management company Posiva Oy has submitted an application for an operating permit for a waste fuel packaging plant and final disposal facility under construction. If successfully approved, this underground nuclear waste repository in Finland will be the first in the world.
Nuclear waste has been a key issue in the world's nuclear energy debate since the first nuclear reactors were introduced in the 1950s. The International Atomic Energy Agency estimates that there are approximately 260,000 tons of highly radioactive nuclear waste in temporary storage globally. Whether nuclear waste is placed in water or in dry storage drums made of concrete and steel, as long as it is on the earth’s surface, it is subject to potential threats such as accidents and leaks.
Many countries such as Germany do not have any long-term plans to dispose of nuclear waste, so Finland will be a global model. Finnish scientists have built a place called Onkalo, which means pit, about 430 meters underground and structured similarly to an ant's nest. Each tunnel is a dead. Spent fuel will first be loaded into copper and steel tanks in the above ground packaging factory. After cooling in pools for a decade, the nuclear waste barrels are transported by robots to the bottom of the tunnels, where they are expected to remain undisturbed for 100,000 years, even as the climate warms or the world moves into the next ice age.
Scientists' argument for the site is that the bedrock has been largely stable for the past billion years and lies between two parallel fault lines approximately 800 meters apart. An earthquake has only happened here at the end of the last ice age when massive glacial retreat caused the bedrock to rebound. Scientists do not expect major earthquakes to occur here until the next ice age.
The only major threat is water. So scientists know that nuclear waste must be located in some type of clay, salt, or hard crystalline rock, because pore space is small, disconnected, and nearly impermeable to water. The nearly 2 billion-year-old bedrock of Onkalo is mostly gneiss, a hard rock formed under high temperature and pressure. Worrying about a final bit of water infiltration, scientists also created a multi-layer barrier of bentonite and copper since the corrosion rate of copper is very slow. If all barriers fail, it will take decades for the nuclear waste to return to the surface, by which time radioactive concentrations would have dropped to safe values.
Scientists at Posiva, a Finnish nuclear waste management company, selected the location 20 years ago and the Finnish parliament approved the decision in principle for the repository project the following year. After that, they began to study local rocks, built an underground laboratory, and applied for a license based on the results. The Finnish government issued a construction permit at the end of 2015 and construction began at the end of 2016.
Now the site is in the process of applying for an operating license and, if all goes well, Posiva is expected to begin burying nuclear waste deep in Finnish bedrock in 2025. The reservoir is expected to be full in 100 years, at which point the entry tunnel will be sealed shut, the surface structure removed, and nothing will be left on the surface, not even a warning sign.
Many experts believe that permanent deep storage such as Onkalo is the best solution. In fact, not only Finland has thought of burying nuclear waste in the ground but only Finland has done it smoothly, not because of the outstanding geological and engineering capabilities of Finnish scientists, but because of the site selection process, government structure, and culture of trust in institutions and expertise. If the same thing is done in a country with low trust, the plan is likely to fail. This issue sparked street protests in France and the Obama administration abandoned plans to develop Yucca Hills, Nevada, into a U.S. national repository.
Experts believe America's failure came from not paying enough attention to community acceptance or engagement. In contrast, the inhabitants of the towns closest to the Finnish repository are almost all nuclear power plant employees and have a good understanding of all operations. In Finland, people trust in science and the authorities highly and if the state says the repository is safe, people do not have to worry, according to experts. The Swedish government has also recently approved a plan for underground storage of nuclear waste, which is still awaiting approval from the Swedish Environmental Court. It is expected to pass smoothly and the two countries will become the first in the world to be responsible for nuclear waste.
(Image：Flickr/IAEA Imagebank CC BY 2.0)