UK Nuclear Expansion Deepens Spent Fuel Storage Problem
Britain is building two large nuclear plants while the long-term repository for the waste they will generate has no funded plan or committed timeline.
Spent nuclear fuel canisters at UK sites, originally designed as an interim storage solution lasting ten to twenty years, may now remain in place for a century or more — with no resolved plan or funded timeline for long-term geological disposal, Energy Voice reported on Monday (2026-08-17). One source described the situation as "a calamity for future generations." The cost of building permanent repositories is acknowledged as a problem; spent fuel also retains significant residual energy, which complicates disposal economics without simplifying the politics of reprocessing.7
This comes as Britain runs its most ambitious nuclear build programme in decades. EDF's Hinkley Point C is under construction; Sizewell C is in development. The UK government expects HPC to deliver up to 3.2 gigawatts of power, enough to supply around six million homes. Both plants will add to the spent fuel inventory. Neither has settled where that fuel will ultimately sit.2
EDF's half-year filing, published on Wednesday (2026-06-03), recorded £1.6 billion paid to Hinkley Point C in connection with the expertise and series effect benefiting Sizewell C, alongside a £3-per-megawatt-hour reduction in Sizewell C's contract-for-difference strike price to £89.5 per megawatt-hour in 2012 sterling. Those figures address the front-end cost structure. Back-end costs, covering decommissioning liabilities and long-term waste management, are not comparably quantified.3
Front-end financing alone is punishing. The Economist reported in May (2026-05-19) that EDF borrowed at roughly 9% for Hinkley, a rate at which accumulated interest on an £8 billion loan exceeds the original principal by the time construction completes. EDF estimates around 60% of HPC's total cost will be financing charges, not physical construction. Each year of delay, endemic to comparable reactor programmes at Flamanville and Olkiluoto, pushes that proportion higher.1
On Wednesday (2026-07-08), the UK energy department agreed with EDF to extend Sizewell B's operating licence by twenty years to 2055 under a new contract-for-difference. The 1.2-gigawatt plant currently supplies around 3% of British electricity, enough to power roughly 2.5 million homes. Chancellor Rachel Reeves called it "a vital part of Britain's" energy strategy. The extension was partly driven by price pressures following the war on Iran. It also extends by two decades the period over which Sizewell B generates additional spent fuel at the Suffolk site.5,4
A large wildfire at Dunwich Heath, near Sizewell, prompted reports on Thursday (2026-07-30) that the plant was on "high alert." EDF dismissed those reports the same day, saying the fire posed no imminent threat and operations were unaffected. The incident illustrated the site's exposure to climate-linked hazards, now a relevant consideration for a plant committed to operate until 2055.6
Sir Geoffrey Clifton-Brown, chair of the public accounts committee, has described Sizewell C as "a project of exceptional scale." The waste liability adds to that assessment: how long-term storage costs will ultimately be distributed between EDF, the UK government, and nuclear liabilities management bodies is not settled, and the cost of the repository itself has no committed delivery date.2
The uranium ETF (URA) gained 3.40% as of 07:52 UTC Thursday (2026-08-20). The back-end liability, comprising spent fuel accumulating in interim canisters with no funded repository and a storage horizon that Energy Voice found has stretched from twenty years to potentially a century or more, does not appear as a settled figure in any public cost estimate for either Hinkley Point C or Sizewell C. How it is ultimately costed and assigned between EDF and the UK government remains an unresolved element behind both projects.7