ET, it also turns out that the UK already has a huge stock of highly enriched uranium – ie. U-235 of 90% purity or higher. It’s enough to run the UK submarine fleet for over a century; heaven only knows why they ever made so much of it. It possibly makes sense to use this for civilian power generation. It’s considered “weapons grade” uranium, so what else could be done with it? Re-mix it with U-238 and bury it again? Guard it for a further century while the submarines use it up achieving, at best, nothing at all?
Its existence possibly helps explain the AUKUS Australian nuclear submarine deal.
High enrichment permits a much smaller reactor core and produces a fraction of the “spent fuel”. Compared with typical enrichment to 5%, this should produce around 1/20th of the waste for the same amount of energy. Reprocessing and reuse of the unfissioned uranium could reduce that still further.