Our method of final disposal

Interim storage of all spent nuclear fuel is currently at the interim storage facility (Clab) in Oskarshamn, where it lies in large water basins that cool the fuel and protect the environment from radiation. 

From interim storage facility to final repository

After interim storage the fuel will be transferred to SKB's encapsulation facility and placed in impermeable copper canisters with ductile iron inserts. They will subsequently be transported to the final repository that SKB is planning to build in Forsmark. The canisters with the spent fuel will then be lowered into a system of horizontal tunnels, at a depth of about 450 metres in the crystalline basement.

Final disposal

It is estimated that the tunnels will be about 250 metres long, and that they will be positioned about 40 metres apart. In the base of the tunnels there will be disposal holes about six metres apart. The copper canisters will be placed in the disposal holes and embedded in a bentonite-clay buffer. When all the spent nuclear fuel has been deposited in the crystalline basement, the tunnels and shafts will be filled in with swelling clay or a mixture of crushed rock and clay.

Bentonite clay protects the canister

The impermeable copper canister fully contains the spent fuel. The bentonite buffer protects the canister against corrosive attack and rock movements. If a fracture occurs in a canister, the bentonite clay buffer and undamaged parts of the canister will prevent water from penetrating into the canister. The buffer will also prevent the leakage of radioactive substances from the canister. The rock provides a natural environment in which the function of the technical barriers is maintained over a very long period. The rock, coupled with the great depth of the deposit, effectively isolates the spent fuel from human beings and the environment.