In terms of submarine reactors, the household dustbin decription relates only to the core size and those  are near the 10-20 megawatts level. Larger container sized  cores generate ten times that. But the shielding of the core, the fueling ad control mechanism and all the rest of the power plant that gets the heat out is several times that volume, so really you need quite a large volume for the complete plant, even in a submarine.

Mike.

the nightstore used [feolite] blocks heated to circa 700 C.  Air was blown through channels and heated water via a heat exchanger all with controls and failsafe to prevent boiling.  IIRC the smaller unit could store c 150kWh. 

Yes, the newly formed NESO is in the process of producing regional energy plans - so call RESPs.  This will be very challenging without good input from customers and installers.  I'm not holding my breath.  see Decision on future of local energy institutions and governance | Ofgem etc

Submarine reactors are a very different kettle of fish to anything commercial.

They often use fuel with very high enrichment levels. Not only is this a proliferation risk, but it's just extremely expensive to enrich uranium. 

The Royal Navy might be perfectly happy running their reactors on very expensive fuel cycles - clearly they have more important operational objectives to worry about. But would that translate into a commercial reactor that can compete with CCGTs? Unlikely.

What RR are developing as an SMR clearly isn't simply a submarine reactor onshore. It's a radical new design, it's complex and won't be any quicker to market if government ministers regularly visit Derby for photo opportunities.

mapj1 said:

core size and those  are near the 10-20 megawatts level

And that's 10-20MW thermal. So much is classified that you need to fill gaps with good old speculation, but I would suspect the operating temperatures are far lower than on a commercial reactor given operating constraints and the need to just keep the noise down.

The amount of work you can practically extract form any thermal plant is limited by Carnot's theorem . The bigger the differential between input and output temperature the more efficient the plant. But if you've got a delicate small nuclear reactor with very expensive precision engineered safety critical parts, you're not going to push the boat out on temperature and risk thermal shock. 

Magnox reactors had loads of space as they were gas cooled, yet they were only about 30% thermal efficiency. I wouldn't be surprised if submarine reactors are less than 5%. The maximum power demand on the propulsion units of an Astute Class submarine is probably only a couple of MW given it's size. Maybe another MW for onboard systems. 

Ultimately anything designed for submarine applications is going to have application specific design decisions which make it terrible for commercial power generation.

Ultimately anything designed for submarine applications is going to have application specific design decisions which make it terrible for commercial power generation.

And in a roundabout sort of way that was really what I was trying to get accross. Remove the constraints of being in a submarine, and you can do a lot more ,  but it ends up being a very different size and shape of beast, but then the 'exam question' is also very different.
A background like RRs of building one may still be a significant head start and confidence boost in building the other, but not simply a copy and paste.

As an aside the nuclear powered aircraft carriers are bigger. https://en.wikipedia.org/wiki/Nuclear_marine_propulsion

M.

Mike.