> microreactors don't seem to have any inherent disadvantages

They have diseconomies of scale. Some of the costs of a nuclear power plant scale sublinearly with power. Neutron economy is improved in a larger core. Larger turbines are more efficient than smaller turbines. It doesn't take 1000x as many operators to operate a NPP with 1000x the power output.

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roenxi an hour ago | parent [-]

Is that relevant? The economics of nuclear plants doesn't have anything to do with efficiency as far as I'm aware, the fuel costs are relatively negligible. They can afford to be horribly inefficient if they can get economies of scale producing the plant. So you can use inefficient turbines and have bad neutron economy and it wouldn't change the economics by anything in particular.

You'd also probably find similar issues with diesel generators, but small diesel generators do roaring trade and have great commercial applications.

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pfdietz an hour ago | parent [-]

Cost is not only relevant, it's paramount. Efficiency is only important insofar as it affects overall cost.

Diesel generators have the advantage of being very cheap -- an order of magnitude cheaper than NPPs per unit power output -- and of having much of their total cost being fuel cost, so they can operate at lower capacity factor. But even so, we don't see large power plants composed of arrays of diesel microgenerators.

(The solution for current higher capacity factor diesel users, like say remote operation at mines, would be to supplement them with renewables and storage to reduce fuel costs. This is already happening.)

A significant problem with any small power plant is fixed costs. A 1 MW(e) plant (Antares is said to be between 100 kW(e) and 1 MW(e)) making power at 90% capacity factor and selling at $0.05/kWh will gross about $400K/year. A single full time employee, like a security guard, will cost a good chunk of that.

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roenxi an hour ago | parent [-]

> Cost is not only relevant, it's paramount. Efficiency is only important insofar as it affects overall cost.

Oh sorry, I thought you were talking about efficiency. Ok, what is the cost is for these plants?

> A single full time employee, like a security guard, will cost a good chunk of that.

I dunno, a 1MW nuclear plant could end up being pretty small. It might easily be economic to install them places that already have security guards.

	▲	pfdietz an hour ago \| parent [-]
		Microreactors have been tried before by the military, for use at bases, which have guards. They not only didn't make sense to install, they didn't make sense to continue to operate once installed.