Finland notifies fuel suppliers of final disposal plans

05 November 2020

Finland's Radiation and Nuclear Safety Authority (STUK) has notified the authorities in charge of radiation safety in the countries that have supplied the country with uranium for its nuclear power plants of Finland's intention to begin the final disposal of used nuclear fuel in the mid-2020s. Normal verification inspections of nuclear materials cannot be performed once the materials have been finally disposed of, and so procedures related to such inspections must be specified before the initiation of final disposal.

An artist's impression of the planned Onkalo repository (Image: Posiva)

Since Finland started up its first nuclear power reactors in the early 1970s, it has mainly sourced uranium from Russia, Australia, Canada and the USA. STUK maintains a national database of nuclear materials and oversees nuclear safeguards in Finland. The International Atomic Energy Agency (IAEA) and the European Commission control Finnish operations to ensure that they comply with the Nuclear Non-Proliferation Treaty.

"STUK has developed several measurement methods for nuclear materials, which have been adopted internationally, and now we are creating procedures for new forms of supervision," said Elina Martikka, head of international cooperation at STUK. "Safeguards will continue in place when the final disposal facility is closed after approximately one hundred years. It is important that all parties can trust that the authorities have accurate information about the nuclear materials in final disposal and that this information will continue to be accessible to the next generations."

Nuclear safeguards help ensure that nuclear materials are used for peaceful purposes alone and do not end up in nuclear weapons. According to one of the principles of the safeguards, the reported nuclear materials must be physically verifiable. However, nuclear fuel deposited in a geological repository can no longer be verified. Therefore, all verification measures must be carried out before the final disposal, STUK said. By notifying the countries supplying uranium fuel, as well as the IAEA and the European Commission, STUK ensures that all parties remain assured that the uranium delivered to Finland continues to be used for peaceful purposes.

Posiva Oy, the nuclear waste management company in charge of nuclear waste management in Finland, is constructing an underground final disposal facility for used nuclear fuel, known as Onkalo. Used nuclear fuel will be placed in the bedrock, at a depth of approximately 450 metres. The disposal system consists of a tightly sealed iron-copper canister, a bentonite buffer enclosing the canister, a tunnel backfilling material made of swellable clay, the seal structures of the tunnels and premises and the enclosing rock.

Researched and written by World Nuclear News