Finland Has Licensed a Nuclear Waste Repository. It Has Not Proved Forever Is Safe.
Wendover Productions makes one of the most consequential promises in its nuclear waste documentary: Finland has found a way to bury radioactive waste so securely that humanity can walk away and never return.
That is an extraordinary engineering ambition. It is not an established fact.
On 22 October 2026, Finland granted Posiva an operating licence for its Onkalo repository, making it the first spent-nuclear-fuel disposal facility in the world to receive one. But the licence does not authorize immediate disposal. Commissioning, testing and a further regulatory inspection must still be completed before operations can begin. Cite ref="turn402096search2"/>
Posiva
That distinction matters. Finland has achieved a major regulatory milestone. It has not demonstrated a million years of safe containment, and no regulator can honestly certify that future.
The problem with Wendover's presentation is not that Finland's engineering is imaginary. It is that a sophisticated, carefully regulated safety proposal becomes, in the telling, something close to a guarantee.
The promised 2020 start became a 2026 licensing decision
The video was published on 21 November 2017. It told viewers that Finland would begin filling Onkalo with nuclear waste in 2020. That did not happen.
Posiva did not submit its operating licence application until 30 December 2021. Finland's nuclear regulator, STUK, issued its favourable safety assessment on 4 August 2026, and the government finally granted the operating licence on 22 October 2026. The first actual disposal hole was only drilled in August 2026. Cite ref="turn575450search10"/>
Posiva
Posiva
Even now, the facility cannot accept spent fuel for final disposal. Posiva must complete commissioning and testing, and STUK must inspect and approve the facility before operations begin. No definitive start date was announced with the licence. Cite ref="turn652752view3"/>
This is not evidence that the engineering has failed. It is evidence that the video's confident timetable was premature. A project requiring more than four decades of research, construction and regulatory review is not something that should have been presented as an almost completed solution in 2017.
The video gets the nuclear waste problem wrong before Finland even enters the story
Wendover states:
“No nuclear waste worldwide is currently in what is considered long-term storage.”
That blanket statement was already wrong when the video appeared.
Finland had been disposing of low- and intermediate-level radioactive waste in bedrock repositories at Olkiluoto since 1992 and Loviisa since 1998. These were established final-disposal facilities, not temporary storage pools. Cite ref="turn262563view1"/>
There is an important distinction: Onkalo is the pioneering facility for deep geological disposal of highly radioactive spent nuclear fuel. It is not the world's first permanent repository for every category of radioactive waste.
That distinction matters because the video repeatedly uses the broad term nuclear waste while discussing the much narrower problem of spent fuel. A technically accurate explanation should not erase existing disposal achievements simply because they do not solve the particular problem being discussed.
Nor is Onkalo an international waste solution. Its licensed spent-fuel capacity is approximately 6,500 tonnes of uranium, from Finland's Olkiluoto and Loviisa nuclear power stations. Finnish law prohibits importing foreign spent nuclear fuel for permanent disposal. Cite ref="turn652752view3"/>
FAQ
Finland is developing a national solution to its own spent-fuel problem. That is significant, but it is not a solution for the world's nuclear waste.
The real safety case is more complicated than “near zero risk”
Wendover describes the Finnish solution as tunnels containing nuclear waste casks, sealed with clay and surrounded by stable rock. But the actual engineering is more sophisticated: each fuel package has a copper outer shell, a cast-iron structural insert, a surrounding bentonite-clay buffer and more than 400 metres of bedrock separating it from the surface. Cite ref="turn262563view1"/>
These are multiple protective barriers. The system is designed to remain safe even if one barrier deteriorates.
That distinction matters because the safety case does not assume that every canister will remain intact forever.
A 2023 technical paper published in Materials and Corrosion, co-authored by Posiva engineers and an external corrosion specialist, examines precisely this problem. Its findings are revealing:
- If the bentonite buffer remains intact, its base scenario predicts no canister failures from corrosion over one million years.
- Natural variations are expected to cause erosion in some deposition holes, increasing groundwater movement and the transport of corrosive sulphides.
- In one variant scenario, the first canister failure occurs approximately 280,000 years into the future, with another 40–60 predicted failures by one million years.
- Under the most conservative assumptions examined, 100–150 of approximately 3,304 canisters could fail within that period.
Crucially, even the most pessimistic scenarios examined remain within the applicable regulatory radiation-dose limits. These are modelled outcomes, not observed failures or predictions that a particular number of canisters certainly will break. Cite ref="turn796038view1"/>
Wiley Online Library
This is the information missing from Wendover's explanation. Onkalo's safety does not depend on a promise that nothing will ever fail. It depends on containing and slowing radioactive releases sufficiently that failures of individual barriers do not become dangerous exposures.
Finland's regulatory framework also does not demand a magical guarantee of zero radioactive release. STUK's Guide YVL D.5 sets a dose constraint of 0.1 millisieverts annually for a representative person under expected future conditions, over a period extending at least several millennia. Cite ref="turn340883search0"/>
The difference between zero leakage and acceptable radiation exposure is not academic. It is the difference between an absolute promise and an engineered safety standard.
Even an outside critic, Edwin Lyman of the Union of Concerned Scientists, describes geological disposal as probably the least bad available option. His concern is that copper canisters will eventually corrode and that scientists cannot eliminate uncertainty about how quickly this will happen. Cite ref="turn830708view0"/>
Finland's geology is stable, not frozen in time
Wendover describes the Finnish location as practically free of natural hazards. Its argument is that the depth and stability of the bedrock make damage to the repository extremely unlikely.
Finland really does have a geologically stable environment, and strong earthquakes are uncommon. But the actual safety assessment has to consider considerably more than ordinary earthquakes.
Posiva's own research examines:
- Future ice ages and continental ice-sheet pressure.
- Permafrost and post-glacial earthquakes.
- Changes in groundwater movement and chemistry.
- Erosion and land uplift.
- Changes in sea level and climate.
Its biosphere studies even estimate that the next glaciation could occur in approximately 50,000 years under one climate scenario, or around 400,000 years under another, depending partly on future carbon emissions. The company acknowledges that uncertainties cannot be avoided when assessing conditions hundreds of thousands of years ahead. Cite ref="turn742046view3"/>
There is an especially interesting connection between climate and the copper canisters.
During future periods when Olkiluoto is submerged, sulphate-containing seawater could penetrate to repository depth. Microorganisms can convert that sulphate into sulphide, a substance that contributes to copper corrosion.
Meanwhile, dilute groundwater can erode the bentonite buffer, allowing faster movement of corrosive substances towards the canisters.
These are not imaginary objections invented by nuclear opponents. They are mechanisms examined in Posiva's own corrosion research and safety models. Cite ref="turn796038view1"/>
None of this proves that Onkalo is unsuitable. It demonstrates why describing the site as a place where no natural phenomenon can damage nuclear waste storage is inadequate.
The engineering challenge is not finding a place where nature stops changing. It is designing barriers that remain protective while nature continues changing.
A million-year prediction is not a million-year demonstration
Posiva's long-term safety case examines a period of approximately one million years. It uses geological research, laboratory experiments, mathematical modelling and evidence from natural history.
STUK independently assessed the documentation before issuing its favourable safety statement in August 2026. The review covered the operating facility and its long-term safety, and the associated assessment documentation extended to almost 20,000 pages. Cite ref="turn543718view0"/>
Long-term safety
There is genuine substance behind this approval.
The OECD Nuclear Energy Agency's 2026 proceedings include a paper by STUK officials describing how the regulator examined Posiva's safety case. They explain that the application used a design status frozen in 2018, while subsequent design changes were assessed through additional documentation, including a 2022 memorandum. STUK emphasized that the combined effects of changes must be examined because the protective barriers depend on one another. Cite ref="turn796038view3"/>
That is how serious engineering should work: test the design, examine changes, challenge assumptions and update the safety case.
But even Posiva acknowledges that it is impossible to comprehensively evaluate every possible future scenario. Its safety case is a demonstration based on the available evidence, not a guarantee against every imaginable development. Cite ref="turn742046view2"/>
Wendover's language makes that distinction disappear.
A facility designed to be safe for an extraordinarily long period is not the same thing as a facility whose safety has been demonstrated for eternity.
Passive safety is real. So is the century of work required to achieve it.
There is one important point on which Wendover is substantially correct.
After all the spent fuel has been deposited, the tunnels backfilled and the facility sealed, Posiva intends the repository to rely on passive safety. Its design does not require continuous maintenance or monitoring after closure. Cite ref="turn791489view2"/>
But reaching that point involves a lengthy industrial and regulatory programme.
The facility is expected to operate well into the 22nd century. STUK supervises its operations, and the safety case must be updated at least every ten years. After final closure, responsibility for the spent fuel transfers to the Finnish State, and essential records must be preserved for future generations. Cite ref="turn543718view3"/>
Finnish Government
The distinction is important: passive safety is the objective after closure, not an excuse to disregard the decades of work, inspections and institutional responsibility required to get there.
Finland has also assigned the financial responsibility to the nuclear industry. Posiva estimates the overall lifecycle cost of nuclear waste management and final disposal at approximately €6 billion, funded by its owners, Teollisuuden Voima and Fortum, through Finland's nuclear waste management financing system. Cite ref="turn791489view0"/>
This is not a simple hole in the ground that solves itself. It is a century-long national infrastructure project with substantial financial, scientific and regulatory commitments.
The verdict: Finland has made progress, not defeated time
Onkalo deserves to be taken seriously. It is the world's first spent-nuclear-fuel repository to receive an operating licence. Its multi-barrier engineering is supported by decades of research, extensive safety documentation and independent regulatory assessment.
I am not arguing that Finland has built an unsafe repository. Nor am I arguing that leaving radioactive fuel in surface storage indefinitely would be preferable.
I am arguing that Wendover makes the conclusion far too easy.
Its blanket statement that no nuclear waste worldwide was in permanent storage ignores Finland's existing repositories for lower-level waste. Its 2020 operational forecast missed by six years. Its description of a virtually hazard-free geological environment omits the future climate, groundwater and corrosion mechanisms that dominate the actual safety case.
Most importantly, it presents near-zero leakage and permanent isolation as though the engineering has already settled questions that scientists must continue to model, test and reassess.
The real achievement is more interesting than the fairy tale.
Finland has developed a carefully engineered system intended to protect future generations even when individual barriers deteriorate. It has obtained a major regulatory approval, but actual disposal has not yet begun.
Onkalo is not proof that humanity has solved the problem of nuclear waste forever. It is the strongest practical demonstration yet that humanity can take responsibility for its most dangerous industrial leftovers without simply passing the problem to the next generation.
That is an extraordinary achievement. It does not need an imaginary guarantee of eternity to be worth recognizing.
References
1. Wendover Productions — The Nuclear Waste Problem (21 November 2017). Original video. Primary source for the claims about permanent storage, the 2020 operational forecast, geological stability and future warnings.
2. Finnish Government — Government grants operating licence for Posiva’s spent nuclear fuel encapsulation and final disposal facility (22 October 2026). Official announcement. Establishes the licence, its conditions, facility capacity, regulatory inspection requirements and transfer of responsibility to the State.
3. Posiva — FAQ (undated, current information). Official technical information. Documents the actual disposal design, existing low- and intermediate-level repositories, Finnish waste restrictions, operating schedule and safety assessment process. Posiva is the project operator, so its technical claims should be read alongside independent regulatory evidence.
4. Posiva — Biosphere Studies (undated). Research overview. Explains future glaciation, groundwater behaviour, changing sea levels and the uncertainties involved in predicting environmental conditions over hundreds of thousands of years.
5. Petri Koho et al. — Treatment of Canister Corrosion in Posiva's Safety Case for the Operating Licence Application (27 April 2023), Materials and Corrosion. Peer-reviewed research. Examines copper corrosion, sulphide transport, bentonite erosion and predicted canister failures under different one-million-year scenarios. Several authors work for Posiva, making this particularly useful for examining the assumptions within the project's own safety case.
6. OECD Nuclear Energy Agency — IGSC Safety Case Symposium 2024: Moving Towards the Construction of a Safe DGR – Getting Real (March 2026). Technical proceedings. Includes a contribution by Finnish regulator STUK officials explaining the safety-case review, design changes and requirements for assessing cumulative effects on protective barriers.
7. Radiation and Nuclear Safety Authority of Finland — Guide YVL D.5: Disposal of Nuclear Waste (13 February 2018). Regulatory guidance. Establishes the radiation-dose constraints and safety requirements governing nuclear waste disposal.
8. Associated Press — A 1.9 billion-year-old bedrock will soon house the world's first permanent nuclear waste site (9 April 2026). Independent reporting. Provides independent reporting from Onkalo and includes Edwin Lyman's assessment of geological disposal, copper corrosion and the remaining uncertainties.