Molten Salt Reactors

The elephant in the room with any kind of fission reactor is that they are going to need a lot of security. Even when the fuel and waste product is not weapons grade uranium, it's still highly radioactive and a great source of material for a dirty bomb. Basically anything that goes boom combined with small amounts of radioactive material and a bit of wind is a great way to depopulate e.g. large cities. So, having lots of small molten salt reactors all over the planet, which seems like the key selling point, is not a great idea from that point of view. Having them in or near any kind of conflict zone would be super risky. And according to this article there is actually some weapons grade uranium being produced as well which makes this even more problematic.

The security aspect would make this a lot more expensive than it already is and cost is already on the high side even before you consider that. This is a problem with traditional reactors as well but they have the advantage that they are huge facilities and that there are only a handful of them; so securing them is relatively easy.

People are suggesting this as complementing renewables but the cold hard truth is that renewables are already dirt cheap and on track to continue to drop in price by magnitudes for the next decades. That includes battery storage as well. Already quite cheap, also dropping in price, and typically already factored into e.g. new solar bids that are killing competing bids for coal and gas plants (or in some cases shutting them down prematurely).

Even at the current prices, that's a problem for any kind of nuclear solutions being contemplated right now. At the low end of the spectrum, we are talking 2 cents per kwh currently. Imagine this dropping to something like half a cent or even less. At those prices, the security alone would make nuclear too expensive probably. A 1 mw facility would have basically be generating only about 500-2000$ worth of energy per hour but only at peak demand. There's no guarantee prices won't drop way below that either. Any kind of operational overhead would be a problem. Needing 24x7 intense security would be very undesirable.

Mostly hard robotics side. This is about replacing people and you don’t send people into heavy radiation areas. It’s like cleaning skyscraper windows, the overhead of keeping people safe is significantly more of an issue than just washing windows.

Decontamination and radiation mostly make it more expensive rather than more difficult.

Perhaps this is hard to calculate because it's unbounded?

Typically:

Known costs for (anything) Maybe there's something wrong with my math?

Are you suggesting that variable renewables plus batteries will approach prices that are... too cheap to meter?

Looking at current cost VRE trends, when variable sources contribute up to 4% of world energy, and surrounded by massive amounts of cheap but high-carbon natural gas, and assuming that the trends will just continue exponentially downward without serious complication, is optimistic.

Cost of integration of variable sources plus batteries is expected in many studies and somewhat intuitively to skyrocket as market penetration increases. When you have enough VRE to cover 100% including the big evening peak with batteries during a clear summer day, the extra generation you build to fill the other gaps gets curtailed. But you have to fill daily and then seasonal gaps, worldwide, including heat in winter and worldwide transportation (not just electricity). Buying that battery that is only even needed at all every third day is 3x the price, yet we prefer if the power doesn't brownout with this frequency. This is difficult. Already we're seeing NIBMYism in large solar installations in california and with transmissions lines. That gets worse with scale.

Nuclear today is a hedge against the possibility that deeply carbonizing with variable renewables + storage at world scale will be harder than we all think and hope it will be.

That said, nuclear certainly needs to drop capital and O&M cost dramatically if it wants to play the game. And security is indeed a big factor in this. Its competition in the small-footprint dispatchable world is natural gas with full CCS, which is also looking pretty cheap.

Also you can also molten salt with the sun, which is done with way fewer moving parts.