Finland’s policy is to dispose of, within its borders, spent nuclear fuel rather than reprocess it. Excavation of a deep geological repository – for final disposal – at Olkiluoto began in May and is a world first. Not even the U.S., with its waste from over 130 nuclear reactors built since the 1950s, has committed to one. James Conca looks at Finland’s history of nuclear waste disposal, how it got to this decision, and the disposal method. The repository tunnels will total a length of about 35 kilometres and will cost €2.6bn ($3.4bn). Nuclear from four plants accounts for 32% of Finland’s electricity. A fifth unit is almost completed and will lift that figure to 60%, completely replacing their coal generation. And some cities are considering the use of small modular reactors to provide district heating. It all amounts to Finland’s clear signalling that nuclear is a big part of its clean energy future.
Among the greatest challenges of the nuclear era remains what to do with all the high-level nuclear waste produced by our existing fleet of nuclear reactors. The preferred method is deep geologic storage. In the U.S., tens of billions of dollars have been spent on proposals to place such nuclear waste under Yucca Mountain, Nevada, or within thick salt layers under Carlsbad, N.M. Yet due to the politics of NIMBY, the United States does not yet have a permanent storage plan.
Finland does. In early May the Finnish waste management company Posiva Oy announced the start of excavation on their deep geologic nuclear waste repository for their spent nuclear fuel (SNF) at ONKALO.
The repository will be the first in the world to start final disposal of spent nuclear fuel.
The Radiation and Nuclear Safety Authority of Finland has certified the process. Operation of the repository is expected to begin in 2023. The total cost estimate is about €2.6 billion ($3.4 billion).
This has been decades in coming. Their disposal program started in 1983 and they have two spent fuel storage sites in operation. Posiva Oy was set up in 1995 to implement deep geological disposal.
Finland has a policy of direct disposal of nuclear waste without reprocessing of SNF. Posiva’s plan is for used fuel to be packed inside copper-steel canisters at an above-ground encapsulation plant, from where they will be transferred into the underground tunnels of the repository.
Last year, Posiva Oy announced the start of construction of the used fuel encapsulation plant at the Olkiluoto site in western Finland.
The repository is in 2 billion-year-old igneous Finnish bedrock.
About one hundred deposition tunnels will be excavated during the 100-year operational period. The repository will total a length of about 35 kilometres, with each tunnel being about 4.5 meters high, 3.5 meters wide and 350 meters long, each holding about 30 canisters.
Nuclear: 32% of Finland’s electricity
Finland has four nuclear power reactors with about 2.7 GWe in capacity that supplies 32% (23 TWhs) of the total electricity in country (70 TWh). These reactors are among the world’s most efficient, with an average lifetime capacity factor of over 90% and average capacity factor over the last ten years of 95%.
Biofuels & waste 13.4 TWh (19%), hydro 13.3 TWh (19%), coal 10.1 TWh (14%), wind 5.8 TWh (8%) and natural gas 4.2 TWh (6%) round out the rest, with oil 0.2 TWh and solar 0.1 TWh contributing a tiny bit.
A fifth nuclear unit (1,600 MWe capacity) is almost completed and will take the country to about 60% nuclear and completely replace their coal generation. Of note, in 2009, Finland’s reactors achieved an average annual capacity factor of 98%.
Finland has had electrical production problems in recent dry years from lack of hydropower. Mostly, the country depends on Russian imports to make up the difference.
A number of Finnish cities are evaluating the feasibility of using small modular reactors (SMRs) instead of fossil fuels to provide district heating, according to Energy for Humanity. A recent study looked at completely decarbonising electricity, transport and heating in Helsinki through the use of small, advanced reactors.
One deep repository, or two?!
Finland’s nuclear waste management program was initiated in 1983, soon after the four reactors started commercial operation. The 1987 Nuclear Energy Act had final disposal as an option, and set up the nuclear waste management fund under the Ministry of Trade and Industry. The Ministry of Trade and Industry ceased operations in December 2007 and its responsibilities transferred to the Ministry of Employment and the Economy.
The 1994 amendment of the Act stipulates that wastes should be handled wholly in the country. Responsibility for nuclear wastes remains with the power companies until its final disposal.
There is a strange political situation in Finland, however.
Another nuclear company, Fennovoima, is building another nuclear power plant, a 1,200 MW unit, Hanhikivi, at Pyhäjoki. Posiva Oy does not plan to include accommodation for used fuel from Fennovoima’s new plant.
Early in 2012 the government threatened to use its legal authority under the Nuclear Energy Act if necessary to ensure that Fennovoima fuel would be included, but when this did not break the impasse it set up a working group to make recommendations.
The working group’s January 2013 report said that Posiva and Fennovoima’s Hanhikivi should continue to negotiate a solution for final storage of spent fuel that takes advantage of Posiva’s experience. It declined to take a position on whether one or two repositories should be built, but said that the difference in cost would be insignificant.
Which is nonsense since duplicating the surface facilities alone is a significant portion of the cost.
But there isn’t enough waste to justified two repositories. For a little perspective, the United States is building just one repository for the waste from over 130 nuclear reactors built since the 1950s. So the waste from four or five reactors just doesn’t get one excited.
Even so, in June 2016, Fennovoima announced plans to build its own repository for spent fuel, having failed to reach agreement with Posiva to share the ONKALO repository. It submitted its own environmental impact assessment to the Ministry of Employment and Economy. Geological studies will be undertaken at Pyhajoki near the Hanhikivi plant and also Eurajoki, near Posiva’s ONKALO repository and the Olkiluoto plant.
The location is to be selected in the 2040s and disposal can begin in the 2090s. Posiva Solutions, a new subsidiary of Posiva, has entered a ten-year contract to advise on the project, and Fennovoima declared that its “goal is to achieve long-term cooperation with Posiva.”
Six sites for deep geological disposal of high-level waste/spent fuel were considered between 1987 and 1999. Construction of an underground rock characterisation facility began in 2004 at Eurajoki. ONKALO will be extended to the final disposal depth of about 400 meters below the surface. Research has been conducted there since the beginning of its construction.
Disposal in any repository in Finland will be based on the multi-barrier KBS-3 system developed by the Swedish Nuclear Fuel and Waste Management Company (SKB). Encapsulation will involve putting 12 fuel assemblies into a boron steel canister and enclosing this in a copper capsule. Each capsule will be placed in its own hole in the repository and backfilled with bentonite clay. The spent fuel will be retrievable at every stage of the disposal process.
At Olkiluoto a surface pool storage for spent fuel has been in operation since 1987. This KPA facility has 1,270 metric ton capacity and is designed to hold spent fuel for about 50 years, pending deep geological disposal. The KPA facility was extended over 2011-2014. Interim storage pools were expanded at Loviisa in 2000.
Near-surface disposal facilities (100 meters depth) for low- and intermediate-level operational waste have been in operation at Olkiluoto since 1992 and at Loviisa since 1998.
For funding of the project, the nuclear utilities make payments into an external National Nuclear Waste Management Fund, managed by the Ministry of Trade and Industry. Contributions to the fund are made over the first 25 years of a plant’s operation. The nuclear utilities are entitled to borrow up to 75% of the fund with the Government able to borrow the remainder.
At the end of 2019, €2.6 billion had been accumulated in the Nuclear Waste Management Fund from charges on generated electricity, which account for about 10% of nuclear electricity production costs. The charges are set annually by the government according to the assessed liabilities for each company, and also cover decommissioning.
The Ministry of Employment and Economy said that the fund will be sufficient to cover all costs for disposing of the amount of nuclear waste and spent fuel now in Finland as well as decommissioning of the operating reactors. The total estimated cost of €3.3 billion for all nuclear wastes includes spent fuel repository operation to 2120 (€2.4 billion) and decommissioning of €200 million.
James Conca is an earth and environmental scientist and a regular contributor to Forbes magazine