In the near future, Finland will entomb nuclear waste in a durable geological chamber designed to endure for 100,000 years.

• Finland is on the brink of becoming the first country to entomb spent nuclear fuel in a geological vault for a century.
• The nuclear energy project has been celebrated as a turning point for the industry's long-term sustainability and an example for global implementation.
• Pasi Tuohimaa, head of communications for Posiva, stated via videoconference to CNBC that a solution for the final disposal of spent fuel was the missing piece of the sustainable lifecycle for nuclear energy.

The world's first geological tomb is set to receive Finland's spent nuclear fuel, with a storage duration of 100,000 years.

The nuclear energy project has been celebrated as a turning point for the industry's long-term sustainability and an example for global implementation.

In the near future, highly radioactive spent nuclear fuel will be securely stored in watertight containers and placed more than 400 meters beneath the forests of southwest Finland.

For millennia, the robust copper containers will remain hidden and distant from people, being stored subterranean.

The facility, known as "Onkalo," is a long-term disposal site located on the island of Olkiluoto, about 240 kilometers from Helsinki. The name "Onkalo" is derived from the Finnish word for a small cave or pit, which aptly describes the repository's location atop a network of tunnels.

Since 1995, Posiva has been responsible for the final disposal of spent nuclear fuel rods at Onkalo. The Finnish company is owned by nuclear power company TVO and utility Fortum.

Pasi Tuohimaa, head of communications for Posiva, stated via videoconference to CNBC that the Onkalo project involves constructing a permanent encapsulation plant and disposal facility for spent fuel.

The first-of-its-kind geological disposal facility has garnered significant interest from industry players due to the recent nuclear "renaissance" and the energy crisis that hit Europe and parts of Asia from mid-2021 to late 2022, as stated by Tuohimaa.

The final disposal of spent fuel was the missing piece of the sustainable lifecycle for nuclear energy, according to Tuohimaa.

The role of nuclear power

The Onkalo project has sparked discussions about the long-term safety of nuclear waste and the role of atomic energy in mitigating climate change.

The World Nuclear Association reports that nuclear energy accounts for approximately 9% of the global electricity supply.

Nuclear energy has the potential to significantly reduce emissions and dependence on fossil fuels, making it a low-carbon option for generating electricity.

While some environmental groups argue that the nuclear industry is an expensive and harmful distraction to cheaper and cleaner alternatives, others support it as a necessary step towards a sustainable future.

Gareth Law, a professor of radiochemistry at the University of Helsinki, shared his experiences in nuclear waste disposal and nuclear accidents with CNBC via videoconference, stating that he has witnessed the best and worst of what the nuclear industry has to offer.

While clean energy can be cheap and provide a good baseload, I have also witnessed the negative aspects, such as accidents, waste creation, and the problems that arise from them.

"Demonstrating that it is possible to safely dispose of hazardous waste, which will remain for 100,000 years, is a significant achievement."

Finland 'at least a decade ahead'

The Onkalo project, as described by Law, represents a significant achievement for both Finland and the global nuclear power sector.

"Posiva is correct in marketing this as a world first. It will be the first repository to safely and robustly dispose of spent nuclear fuel into the future."

Finland is "at least a decade" ahead of neighboring Sweden in the geological disposal of spent nuclear fuel, as stated by law.

"While it is challenging from both a scientific and engineering standpoint to implement this disposal plan, politically it is also extremely difficult to gain the necessary momentum to take action," Law stated.

"Finland has constructed a waste repository, which will soon begin the disposal process. This is a significant achievement, given that many countries are still in the planning stages and struggling to find a location for waste disposal. While it may not be a miracle, it is certainly a remarkable accomplishment in the global context."

'A model for the entire world'

The Onkalo project utilizes the "KBS-3" method, developed by the Swedish Nuclear Fuel and Waste Management Company, for the construction of what could be the world's second final nuclear waste repository.

The KBS-3 system employs a multi-barrier approach to safeguard the long-term security of spent nuclear fuel. In the event of a barrier failure, the radioactive waste remains isolated.

Finnish Climate Minister Kai Mykkänen stated via videoconference to CNBC that despite being a small nation, Finland is capable of addressing one of humankind's top 20 problems or challenges.

During the past 10 years, nuclear has become crucial for the green deal in Europe, particularly if we want to eliminate fossil electricity production in Asia and the U.S.

Could the Onkalo project be viewed as a solution to nuclear waste sustainability? Mykkänen responded affirmatively, saying "Yes, definitely."

He stated that the majority of the Finnish population, as well as those near Onkalo, view the project as a harmless solution to energy needs.

Mykkänen expressed the hope that the Onkalo project would serve as an example for the global community.