The UK’s Nuclear Decommissioning Agency has published a report (Geological Disposal: Steps Towards Implementation) of its preparations for a geological repository for nuclear waste that would be expected to begin operation in about 2040.
Artists’ impression of a buried UK waste repository (above ground)
It estimates preliminary studies will take five years. This includes host community work–the repository requires volunteers–an initial suitability test that aims to exclude inappropriate geologies, (due later this year), and conceptual facility design. The next phase is surface-based investigations, and borehole drilling, which will take 10 years. Construction and underground-based investigation will take a further 15 years.
So far, only two communities have volunteered: Copeland borough council, which runs the area that includes the Sellafield nuclear site, and the neighbouring Allerdale Borough council.
Three types of rock have been considered for the repository design. They are higher-strength rock such as granite, lower-strength sedimentary rock, or evaporites such as rock salt.
Because of the many uncertainties in repository planning – the amount of waste, the geological setting, facility design–the UK government has written a reference case programme based on data from the failed Nirex programme to write a tentative initial schedule, and make other preliminary planning decisions. This reference design consists of a single repository in higher-strength host rock, 650m deep, with two distinct areas. One area holds ILW, LLW and uranium residues, and the other holds HLW, spent fuel, plutonium and highly-enriched uranium. The reference case refers to disposal concept of KBS-3V concept in Sweden and Finland.
It estimates the repository would cost GBP12 billion (14.3 billion) without discounting, or GBP3.7 with discounting. Storing existing stocks of separated plutonium and uranium would cost another GBP2 billion. The cost up to the first planned emplacement in 2040 would be GBP4 billion, excluding waste encapsulation and transport, which will be paid by waste owner.
