While I am very much in favor of switching over to all-nuclear, all the time, I really wish the emphasis would be on building SMR clusters instead of 1.2GWe reactors that are incapable of passive cooling without a constant electrical supply. We all know about Fukushima; after a a Category 5 hurricane in 1995 a nuclear power station (or was it two?) in Florida were running their primary cooling loops on diesel backups for the better part of two weeks. If they had run out of diesel then what happened at Fukushima would have happened in Florida 17 years earlier.
The additional benefit of SMR clusters is that the cost per unit would come down as more are made and if the production is up and going then the idea of putting in much smaller two or three unit stations throughout the grid, closer to the sources of demand.
There's greater efficiency in larger sizes. Reactor walls scale with surface area, their output scales with volume. There's also regulatory issues, too. I'm not sure how the UK operates, but in the US every nuclear reactor - regardless of size - has to pay $375 million in insurance. And there's a push to increase this to $450 million [1]. This fixed overhead regulatory cost effectively prohibits anything but the largest reactor designs, as 50 SMRs producing 1.5 GW total incurs 50x the regulatory cost as one 1.5 GW reactor.
SMR design allows them to cool themselves with only natural water circulation when in a scammed state and no external power to the cooling loop. In short: you cannot have a melt-down. The trade-off is that it's much smaller so you would need a cluster of 8 to 12 SMR units to match the typical 1.2GWe reactors used for most utility-grade installs.
Fukushima melted down only after the batteries supplying power to the primary cooling loop ran out. Normally diesel generators would have provided power but they were located low enough that the tsunami took them out of commission. Had the backup diesels been located higher up -- as had been recommended to TEPCO -- then all would have been well at Fukushima Daiichi.
The Bristol Channel was hit by a tsunami in the 1600s. And a couple of nuclear stations in the UK had to have work done to address that risk after Fukushima. But it seems like a risk that can be mitigated. Build a massive bund, elevate critical gear and have a plan for backup generators.
UK Govt announces it will build nuclear reactors again for the nth time during transient energy crisis.
Who believes these will ever get built?
What we needed was a programme, not a project.
The additional benefit of SMR clusters is that the cost per unit would come down as more are made and if the production is up and going then the idea of putting in much smaller two or three unit stations throughout the grid, closer to the sources of demand.