Fuel transfer trolley in place at Finnish encapsulation plant

Tuesday, 13 February 2024

The trolley - measuring about five metres by four meters and weighing some 30 tonnes - was manufactured by the French company CSI and delivered to the encapsulation plant in early February.

The trolley has now been moved from the fuel reception hall one floor down and placed on the rails on which it will operate.

The transfer trolley plays both a central and versatile role in the final disposal process, Posiva said. It not only receives the transport casks upon arrival but also transfers, lifts, and inserts them into the docking station. One challenge is that all of this takes place in a rather compact space within the transfer corridor.

The transfer trolley (Image: Posiva)

The fuel transport cask transfer trolley is the first link in the used fuel handling phase. The used fuel is transported to the encapsulation plant from Teollisuuden Voima Oyj's (TVO's) interim fuel storage using a transport cask. A docking preparations station is provided between the reception point and the docking station, where maintenance activities and measures that prepare the cask for docking and undocking are carried out on the cask.

"This is yet another important milestone at the encapsulation plant," said Installation Manager Veijo Ruotanen, who is in charge of the installation of the main equipment at the encapsulation plant. "Having the equipment specifically designed for this purpose ready for operation and in place and installation work progressing at a good pace is a major accomplishment."

The encapsulation plant is part of Posiva's final disposal facility complex. Once the final disposal operation starts, used nuclear fuel will be transported from interim storage to the encapsulation plant where it will be packed into final disposal canisters made of copper and spheroidal graphite cast iron. From the encapsulation plant, the cannisters will be transferred into the underground tunnels of the repository, located at a depth of 400-450 metres, and further into deposition holes lined with a bentonite buffer.

Skanska Talonrakennus Oy, the contractor responsible for construction of the used fuel encapsulation plant, handed over the building - some 72 metres in length and about 40 metres wide - to Posiva at the end of May 2022 for installation of the nuclear systems and commissioning of the process systems of the encapsulation plant.

The site for Posiva's repository at Eurajoki, near the Olkiluoto nuclear power plant, was selected in 2000. The Finnish parliament approved the decision-in-principle on the repository project the following year. Posiva - jointly owned by Finnish nuclear utilities Fortum and TVO - submitted its construction licence application to the Ministry of Employment and the Economy in December 2013. Posiva studied the rock at Olkiluoto and prepared its licence application using results from the Onkalo underground laboratory, which would be expanded to form the basis of the repository. The government granted a construction licence for the project in November 2015 and construction work on the repository started a year later. The repository is expected to begin operations in the mid-2020s.