Approval for expanded Olkiluoto repository

04 June 2009

Finland's nuclear waste management company Posiva should be allowed to expand its planned used nuclear fuel disposal facility, the country's radiation and nuclear safety authority has ruled.

Posiva is jointly owned by Finnish nuclear generators TVO and Fortum, and is responsible for the final disposal of spent nuclear fuel from Finland's currently operating plants. It applied for a decision-in-principle from the country's government to allow it to expand its planned final repository for used fuel to accommodate that arising from the as-yet unbuilt Olkiluoto 4 nuclear power plant in April 2008. The expansion would increase the capacity of the repository by about a third from the initial plans.

Stuk, the Finnish radiation and nuclear safety authority, says it has now made its preliminary safety assessment of the decision-in-principle application and has told the Finnish government that in its opinion, there are no nuclear safety-related obstacles to expanding the facility. The fuel from the new unit could safely be placed into available disposal area at the Olkiluoto site, says Stuk.

The site for Posiva's repository at Eurajoki near Olkiluoto was selected in 2000, and Posiva is already building an underground characterisation facility known as Onkalo with a view to operation of the repository starting from 2020. The repository site will also house an encapsulation plant that will encase spent fuel assemblies into steel and copper canisters ready to be embedded in clay within a network of tunnels some 400 metres underground in solid bedrock.

Finland has four operating nuclear units with a fifth - Olikiluoto-3 - under construction. Environmental impact assessments are under way for possible new reactors at the two existing nuclear sites (TVO's Olkiluoto 4 and Fortum's Loviisa 3). In addition, joint venture Fennovoima has submitted a decision-in-principle application to build a nuclear power plant at one of three possible new sites.

Posiva submitted a decision-in-principle application for an expansion of the repository to accommodate spent fuel from Loviisa 3 in March 2009. Such an expansion would increase the total capacity of the repository to some 12,000 tonnes of uranium, according to Posiva.


Some issues could arise concerning Fennovoima's bid to build a new reactor because Posiva is owned by TVO and Fortum. The requirement for Fennovoima to show a disposal route for its used nuclear fuel - as well as other radioactive materials - would appear to necessitate it taking part ownership of Posiva, a matter that its rivals TVO and Fortum could affect.