In reply to Richard J:
> One other way a land-based small reactor is easier is that it doesn't need to be as small as a sub reactor.
Good point, thanks.
> I think submarine reactors run on much more highly enriched uranium, that wouldn't be acceptable in a civil reactor
You say that, but I believe the Russian civilian nuclear powered icebreakers such as the Yamal -
https://en.wikipedia.org/wiki/Yamal_(icebreaker) - run on highly enriched uranium. They also carry fee-paying tourists. Insane. I assume but don't know that their plans for floating civilian nuclear power plants are also based on highly enriched fuel. Then again are they really for civilian use or are the intended to aid a future war with China over Siberan resources...
Just because the Russians do something, doesn't mean that we should...
> (and would be out of the question for export markets for proliferation reasons). Their small size and high power density makes them more susceptible to loss of coolant accidents. On the other hand a post-Fukushima civil design would probably need to have enough passive cooling (e.g. through convection) that it would survive a loss of coolant accident at the same time as a complete loss of back-up power.
It's a mystery to me why more passively safe designs such as the pebble bed haven't become more common. In terms of designing for a Fukushima-level disaster event; you start to get to the point where you'd be better of spending the additional money on protecting the civilian population from the triggering threat, as that will kill far more people than the containable reactor incident. Close to 16,000 people were killed within minutes by the triggering disaster. Around 8,000,000 people are being killed a year by air pollution from fossil fuels. At some point it becomes sensible to accept a design that will have manageable problems after one of the worst earthquakes in recorded history followed by one of the worst tsunamis, because that is less bad than the alternatives. Not going to happen, however. We'll continue to see more people killed per kWh by wind and solar power than by nuclear...
> It's not that I think Rolls isn't capable of designing and building a civil SMR, it just won't be a direct copy of the submarine design. And whether they can do it for a more cost-sensitive environment than money-no-object MoD procurement remains to be seen.
Agreed. I don't know how much knowledge actually resides within the UK these days vs stuff bought in from the USA, and if the bits we get from the USA would be allowed to be used in civilian plant where the designs must be open to international scrutiny.
Post edited at 23:00