Preliminary findings positive for Swedish repository

The Swedish nuclear regulator has said it believes the country's radioactive waste management company can meet all the safety and radiation protection requirements for its planned repository for used nuclear fuel.

The Swedish nuclear regulator has said it believes the country's radioactive waste management company can meet all the safety and radiation protection requirements for its planned repository for used nuclear fuel.

An artist's impression of the planned repository concept, with its 66-kilometre network of underground tunnels (Image: SKB)

Svensk Kärnbränslehantering AB (SKB) submitted its application to build the country's first repository for used nuclear fuel, together with a plant to encapsulate the fuel prior to disposal, to Sweden's Radiation Safety Authority (Strålsäkerhetsmyndigheten, SSM) in March 2011.

The regulator has now outlined its preliminary findings from its ongoing review of SKB's application to build and operate the repository.

SSM section head Ansi Gerhardsson said, "Our preliminary assessment is that SKB has demonstrated that there are prospects for meeting the authority's nuclear safety and radiation protection standards in connection with rock excavation, the handling of disposal containers in the underground facility and emplacement of the waste in accordance with SKB's concept for final disposal."

She added, "As far as the initial status of the repository after closure is concerned, that is, the starting point for analysis of long-term radiological safety, our assessment is also cautiously positive. However, further investigation work is needed in order for us to take a position on further aspects of SKB's account of how the repository is expected to comply with radiation safety requirements over a minimum period of 100,000 years."

SSM said that "certain issues remain to be solved in respect of the repository's assumed status at closure." These, it said, primarily relate to the manufacture of the copper canisters in which the used fuel will be stored within the repository. It said it needs to continue its review work in order to determine whether the underlying documentation is sufficient for this step of the licensing process."

Helene Åhsberg, project manager for licensing at SKB, welcomed the regulator's initial findings, saying: "The permitting review for the used fuel repository is a gradual process, and therefore it is positive that we have taken a step forward with these preliminary results. We have also received valuable input to take with us in future work. Although these are preliminary assessments, it is of course gratifying that SSM believes we have the potential to meet the requirements, a confirmation that we are on the right path," she added.

SSM intends to publish additional preliminary findings throughout 2015. It plans to submit an opinion on SKB's overall licence application to the Land and Environment Court in Stockholm in early 2016. The regulator will deliver its comprehensive final assessment of the application to the government in 2017. SKB plans to start construction of the repository as soon as the government issues a permit, expected sometime in the early 2020s.

Gerhardsson noted, "The outcomes we have presented today are preliminary and it is too soon to draw any conclusion regarding our future overall assessment."

Sweden's used nuclear fuel is currently under temporary storage at the interim storage facility (Clab) in Oskarshamn. SKB plans to build a used fuel repository at Forsmark in Östhammars municipality. The method that has been developed involves first encapsulating the fuel in copper canisters, which are then sealed and placed in a system of tunnels about 500 metres deep in the solid bedrock. Here they will be embedded in Bentonite clay.

In February, Finland's radiation and nuclear safety authority, STUK, gave its backing to Posiva's application to construct a final repository and waste encapsulation plant. The planned KBS-3 repository for used nuclear fuel would use the same storage method as that which SKB wants to use.

Researched and written
by World Nuclear News