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smopecakes's avatar

I don't know how likely it is but there appears to be an emissions or cost risk with greatly expanded conventional nuclear. Ore grades are expected to decline and the energy to mill in particular rises exponentially. Mines using current energy mixes would result in nuclear at 60gCO2/kWh in 2050 rather than 12g as it is now. Still low but notable

Milling is an electric powered activity so it may not be difficult to deliver low carbon energy to the mines to offset this, but the remoteness of the mines could make that pricey. With LFRs able to use the whole ore this effect would entirely dissappear for the reasonable future

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Incautious Optimism's avatar

That's interesting, I'd not heard of that. I suppose if it's true it would logically raise the expense of processed Uranium fuel and so make fast reactors a better business case over time. A problem that solves itself... given a few decades. :D

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Niels Harksen's avatar

One can also use in-situ-leeching and with fast breeder reactors, Uranium adsorption from seawater is economical.

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Jesse's avatar

You could use a solar salt secondary circuit, which you would need anyway for thermal storage.

That would put the steam generators outside the containment *and* potentially outside the nuclear regulatory scope.

Solar salt also has a ~550C practical limit, so it's a good pairing.

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Niels Harksen's avatar

A major theoretical advantage that implicit in the characteristics of LFRs you describe is the reduced size of the containment building to due atmospheric pressures. The large volume and height of the containment building is the reason even a very efficiently run PWR construction project takes so long compared to a similar sized coal power station.

The higher operating temperature leads to higher thermal efficiency and power density of the turbine and less waste heat. So the power conversion system and the heat sink can be more compact. The waste heat release into the environment per kWh electric is also reduced, making environmental permits easier and reducing the cost increase from dry cooling towers if they are deemed necessary.

Ship reactor applications of LFRs are also interesting because of the safety characteristics: Good passive safety and low pressures, no/few gas filled cavities in the reactor that are problematic during sinking such as with gas cooled reactors and no water soluble primary coolant such as salts.

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