It is planned that the spent fuel from Sizewell C&D will be moved to a final ‘geological repository’ in about 2130¹. At a recent consultation meeting, EDF gave the impression that the technology to do so was well understood and that deep geological repositories already exist in Finland and Sweden.

This is far from the truth. The repository in Finland (operated by Posiva) is currently in the evaluation stage and is not expected to start operation until 2020². The proposed repository in Sweden (operated by SKB) is scheduled to start operation in 2025³ (Note that I originally gave the date of 2070), however this is the date when construction will be complete but spent will start being placed in the repository from 2025 – thanks to Simon Carroll for pointing this out – see comment below). There are also many concerns about the ability to seal spent fuel from the environment for a sufficient amount of time⁴.

Both repositories are relatively small compared to the amount of spent fuel which will be generated by the UK nuclear programme. The repository at Olkiluoto in Finland will hold 6200T of spent fuel while that at Forsmark in Sweden will hold about 12000T. If Hinkley and Sizewell C&D go ahead they will produce 7200T of spent fuel⁵. In the UK some of the reactor fuel may be reprocessed, however at leat another 12,000T will be needed to be stored⁶.

¹ Spent Fuel Management – EDF Energy Perspective,EDF Energy March 2012 (http://www.nuleaf.org.uk/nuleaf/documents/Nuleaf_presentation_09032012_final.pdf)

2 General Time Schedule for Final Disposal, Posiva (http://www.posiva.fi/en/final_disposal/general_time_schedule_for_final_disposal)

3 A repository for nuclear fuel in 1.9 billion year old bedrock, Swedish Nuclear Fuel and Waste Management Company, SKB  (http://www.skb.se/Templates/Standard____28848.aspx)

4 Olkiluoto waste dump: Deadly legacy under the Baltic Sea, Greenpeace 2010 (http://www.greenpeace.org/finland/Global/finland/p2/other/report/2010/nuclearWasteBriefing.pdf)

⁵ Amounts of spent fuel in the repository is taken from references 2 and 3. However it must be noted that there is a difference between the amount expressed in tonnes of Uranium and tonnes of UO₂ – 5500T of uranium is equal to 6240T of UO² – you have to multiply by the molecular mass of UO₂ (270) and divide by the atomic mass of Urnaium (238).

⁶ Spent Fuel Management: Life Cycle Analysis Model, Nuclear Decommissioning Authority 2007 (http://www.nda.gov.uk/documents/upload/Spent-Fuel-Management-Life-Cycle-Analysis-Model-Report-September-2007.pdf)