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Hold on there buddy. All Western designed PWRs or BWRs (which is nearly all of them) are not designed to be yielding bombs. Their neutron flux is simply not high enough to give enough enrichment.

Two other types of plants you might be thinking of when taking bomb materials into account. The russian design for Chernobyl was meant to produce electricity and bomb fuel which is why it had a graphite moderator which creates a very high neutron flux.

The other one is the sodium cooled breeder reactor which we chose instead of the molten salt design discussed in the article. The sodium breeder was good at making plutonium but still was never designed to have that plutonium removed in any usable fashion. Sodium is a tricky substance it reacts with water violently. The french still have a plant or two going as do the Chinese but it's really not a stellar design.

Now, I agree about the temps and pressures being unnecessary. The reason for these is about efficiency of scale. In a power grid like America's where we need 1 gigawatt and greater plants, plus with licensing a plant being so difficult, you build the biggest baddest plant you can which can output the most power. This means you go with the highest temps and pressures while still being ultra safe to create a more power efficient reactor.

Smaller reactors which would be better for the power grids of the world. Like 250 mega watts would not need these extreme environments. There are some great designs for a back of trailer truck reactor which can just hook up to a coal plant's secondary systems (steam turbines and such).

The best part of nuclear startups is nuclear is not a 'if' question. It's a when. I just hope we can disrupt quickly enough to bring that sort of power production here sooner rather then later.




"Now, I agree about the temps and pressures being unnecessary. The reason for these is about efficiency of scale. In a power grid like America's where we need 1 gigawatt and greater plants, plus with licensing a plant being so difficult, you build the biggest baddest plant you can which can output the most power. This means you go with the highest temps and pressures while still being ultra safe to create a more power efficient reactor. [P] Smaller reactors which would be better for the power grids of the world. Like 250 mega watts would not need these extreme environments."

This isn't actually accurate. Reactor core water is pressurized to raise the boiling point -- at 0.1 MPa (atmospheric) it's 100 ºC, at 15 MPa (reactor coolant) it's 342 ºC, so they can push water to around 300 ºC and still keep it liquid in the core. The higher the temperature, the higher (in general) the efficiency of converting heat to work (in the case of nuclear plants, efficiency of the steam turbine). This is pretty much independent of the size of the reactor.

(Why liquid water? One huge reason is neutronics (the nuclear part): a very high density of hydrogen nuclei (H in H2O) is useful for scattering neutrons, which slows them down to speeds where they get absorbed by heavy nuclei (reactor fuel) and start fission reactions. [This isn't necessary: in fact "fast reactors" work with neutrons flying at relativistic speeds. But it's much easier.])

300 ºC is actually pretty cool; the steam from coal power plants gets up to around 600 ºC [1], and internal-combustion gas turbines can reach temperatures of even 1,600 ºC [2]. Water-cooled reactors are held back in efficiency by the need to keep water liquid at core temperatures. Conceptually they can get a bit further by pressurizing water to supercritical conditions [3], at about 510-550 ºC/25 MPa; these aren't being built. (These are fast reactors; the density of this supercritical water is very low, about 0.1 kg/L, so it's a weaker moderator).

[1] http://www.ge-energy.com/products_and_services/products/stea...

[2] http://www.mhi.co.jp/en/news/story/1105261435.html

[3] http://www.gen-4.org/Technology/systems/scwr.htm


Thanks for the citations.

Btw are you the same uvdiv that writes on capacity factor? Used to read that blog all the time when I was in industry. Always liked the number focus.


Yeah I'm the same, thanks! :)




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