Major construction work progresses on Posiva's ONKALO worksite


Major construction work progresses on Posiva's ONKALO worksite, both in underground facilities and above ground in encapsulation plant. The excavation of the first five actual final disposal tunnels was completed in the underground repository just before the Mid Summer's Day in June. The Deposition Hole Boring Machine arrived from Germany in June and the first deposition holes have already been bored.

On the outside, the encapsulation plant looks already almost finished.

On the above-ground worksite, the handover of the encapsulation plan building from Skanska to Posiva took place in late May. The project has since continued with installation of various equipment. The arrival of the welding station and its transfer to the installation site was one of the most impressive examples of equipment installation works at the turn of October to November. The installation of the drying station for spent nuclear fuel was wrapped up at about the same time in the fuel handling cell. The final disposal of spent nuclear fuel in Olkiluoto by Posiva is scheduled to start in mid-2020s.

The in­stal­la­tion of var­i­ous equip­ment con­tin­ues in the can­is­ter han­dling cell.
The ma­nip­u­la­tor will come to as­sis­tance, if an ex­tra pair of hands is needed dur­ing the en­cap­su­la­tion process in the can­is­ter han­dling cell.
The con­trol room of the en­cap­su­la­tion plant pro­vides a di­rect view also to the han­dling cell.
The fuel dry­ing sta­tion on its way to the in­stal­la­tion site.
The De­po­si­tion Hole Bor­ing Ma­chine bores ca 8 me­tres deep holes in sta­ble bedrock. The bor­ing of one hole takes about 10 hours.
The can­is­ter weld­ing ma­chine has reached its fi­nal in­stal­la­tion site. The qual­ity of the weld­ing car­ried out to in­stall the ma­chine is be­ing in­spected in the photo.
The sep­a­ra­tor is used to sep­a­rate solids from the sludge dur­ing the bor­ing process.
In the trans­fer cor­ri­dor, the fi­nal dis­posal can­is­ter will travel in an up­right po­si­tion in an over­head con­veyor and lift­ing de­vice run­ning on rails.
De­po­si­tion Hole Bor­ing Ma­chine
De­po­si­tion Hole Bor­ing Ma­chine
Crushed floor in the first ac­tual fi­nal dis­posal tun­nel.
The de­po­si­tion hole bored with the new Bor­ing Ma­chine for the joint func­tional test.

Text Pasi Tuohimaa
Photos Tapani Karjanlahti, Markus Forsberg, Pasi Tuohimaa