Conventional Nuclear (AKA Nuclear Fission) a thread for discussion of the pros / cons.

Look at the Lazard Levelized Cost of Energy:

https://www.lazard.com/media/451905/lazards-levelized-cost-of-energy-version-150-vf.pdf

This data is from the industry. It is reliable. It shows the cost of nuclear plants is:

$7,800 - $12,800/kW of capacity. The one under construction in Georgia costs $13,000/kW so far.

The levelized cost of electricity, disregarding subsidies, is: nukes $204/MWh, solar $41, wind $50.

Building a nuclear power plant is economic insanity. Nobody wants to pay 5 times more for electricity than they would from the cheapest, cleanest source, which is solar. The power companies are installing far more solar than any other source because it is the cheapest source. Nuclear power is obsolete. It costs far too much. It is dangerous. The Fukushima accident bankrupted TEPCO, the largest power company in the world. There is no chance nuclear fission will catch up. I doubt that tokamak plasma fusion will ever become practical either.

Solar power will account for nearly half of new U.S. electric generating capacity in 2022

www.eia.gov

Quote from Curbina

Have you seen any similar analysis for the Liquid Thorium Fluoride Reactors that are being developed?

I have not. Lazard and the EIA compile data from the electric power industry. Their databases list these sources. They do not compile data from experiments or speculation in physics papers.

I meant that conventional fission reactors will never catch up with solar or wind. It is too late for that. Once a technology falls behind the competition, it seldom recovers. The only counter-example I can think of are electric cars. They were abandoned in the early 20th century and they came back starting in the 1990s. But modern ones are radically different from the early ones. So different, I think you can categorize them as a new technology.

A radically new fission reactor design, such as the pebble bed, might be competitive. I do not know enough about this to judge.

Quote from Wyttenbach

All nukes produce the same mess. Decommission is the main cost.

I do not think it is the main cost. For the following reasons --

Decommissioning costs are paid by the power company during operation. They range from $0.46 to $0.73 per megawatt-hour. See:

Nuclear Decommissioning: Decommission nuclear facilities - World Nuclear Association

Several nuclear plants have been decommissioned successfully, within the budget. If one of them melts down like Three Mile Island, or explodes from hydrogen like Fukushima, I suppose decommissioning costs would go through the roof. (Along with tons of radioactive debris.) The Connecticut Yankee plant was so mismanaged that, as the state attorney general put it: "What we have here is a nuclear management nightmare of Northeast Utilities' own making. The goal is no longer to decommission a nuclear power plant, but rather to decontaminate a nuclear waste dump." I guess that cost a lot! However, when the power company is competent and no serious accident occurs, it seems decommissioning is predictable and the cost is moderate.

I do not know whether anti-nuke people would be satisfied with decommissioning, but government regulators and the industry say it works and the sites are safe. $0.73 is a small fraction of the total cost of operating a nuke. Lazard shows the unsubsidized levelized cost of energy from nukes ranges from $131 to $204/MWh, so $0.73 is only 0.6% of the cost.

Of course there is no permanent storage of spent fuel yet, but the amount of fuel is surprisingly small. I do not think it would cost much to store it somewhere for a few hundred years. After that, a better, cheap, long term solution is likely to emerge, such as sending it up an ultra-reliable space elevator and dumping it into the sun. But that is mere speculation.

(As I said before, paying $131 to $204/MWh for electricity is economic lunacy. It is 5 times more than solar! You can bet it does not cost $0.73/MWh to decommission a 1 GW solar array. No power company exec in his or her right mind would contract to build a nuke given these costs. Forget about the environmental or global warming arguments: people will not pay 5 times more for electricity when there is 100% clean solar, and enough offshore wind energy to generate 18 times more power than we now use.)

Quote from GRMattson

With wind and solar there needs to be infrastructure in place to provide the power difference when either or both are off line during peak demand hours. That will reduce that 5 times factor and can not be ignored. You got numbers for that?

All energy sources require that infrastructure. A nuclear reactor has to be turned off periodically for refueling and maintenance. Nuclear reactors sometimes stop abruptly in a SCRAM event. That is usually a plumbing problem, such as kelp clogging up the inlet pipe after a storm. Or the clogged up pipe that triggered the Three Mile Island meltdown. When a nuke goes offline, you need 1 GW of backup power from other sources. It has to be available instantly. The NRC lists all SCRAM events on line. You can see they are unpredictable.

When a gas turbine fails or is turned off for maintenance, you lose 200 MW. When a wind turbine goes down you lose ~1 MW, which is easily compensated for. When wind turbines are turned off for maintenance they are done one at a time. Wind turbines produce less power when there is less wind, but with modern forecasting this can be predicted a week ahead of time, so other sources can be prepared. In the obverse, maintenance to a gas turbine is scheduled when there will be a lot of wind and wind turbines can compensate.

Hydroelectric dams and solar panels hardly ever fail. They are the most reliable sources. Again, solar varies with weather, but you know ahead of time. They do not fail suddenly and completely, taking out 1 GW, the way nukes do. Nukes require the most infrastructure and back up power, because they are the largest and most unpredictable energy source.

Quote from GRMattson

With wind and solar there needs to be infrastructure in place to provide the power difference when either or both are off line during peak demand hours. That will reduce that 5 times factor and can not be ignored.

I do not understand why you say the backup power for wind and solar will reduce the 5 X cost advantage over nuclear power. You don't back up wind power with a nuke! Nukes are run constantly, as baseline power, because the capital cost is high but the fuel is cheap. (But not as cheap as wind or solar!) You back up wind turbines with wind turbines elsewhere, or solar, or peak power natural gas. Over a large area, such as the entire state of Iowa, the wind always blows somewhere, to some extent, so wind power is always available. Wind would only stop over the entire state if the sun turned off. (Iowa produces 42% of its power from wind.)

Diesel and natural gas peak generators are used to compensate for wind on days when there is not much wind, or during maintenance, or at peak hours. They are dispatchable. As you see at Lazard, the capital costs are low but the operating costs are high, because you have to pay for fuel. The cost of energy for gas peaking ranges from $151 to $196/MWh, which is almost as high as nukes (p. 2). You want to run something like that as seldom as possible. The capacity factor is 10% (p. 18) compared to 38% for wind. You could run them more than 10% of the time, but you would be burning money. The combined cycle gas capacity factor is up to 70%. Compare the capital costs per kilowatt of capacity to see how this works.

https://www.lazard.com/media/451905/lazards-levelized-cost-of-energy-version-150-vf.pdf

In short, for the cheapest possible power you need a mix of solar, wind, combined cycle gas, and peaking gas and Diesel, turned on at different times, depending on conditions. With hydro if it is available. It is complicated. You could not build a system with only wind, because it varies with weather. You could not build a system with only nukes because you cannot turn them off at night when demand falls by half or 2/3rds. You have to have dispatchable peak capacity with wind, solar or nukes. Every plant of every type has to have enough backup power elsewhere to compensate if it goes down abruptly. That does not mean a different kind: peak gas might be compensated by another peak gas generator elsewhere. A nuke you have already paid for is economical. Building a new one is crazy. Coal is like burning money.

Quote from GRMattson

I have come around to the point of view that when a wind farm or solar is proposed the developers should also provide the extra capacity by some means such as water impoundment for when their generation is off line.

That is not necessary. You just need dispatchable sources. The same rule applies to coal, gas or nuclear power. They all go off line from time to time. As long as there is enough dispatchable generators or stored energy, power is not interrupted and no harm done. There is no particular reason to demand this for wind or solar but not for coal or nukes. Wind and solar are more reliable and predictable than nukes, as I said.

Things can go wrong, of course. The Texas 2021 power failure was caused by cold weather interrupting the flow of natural gas and also shutting down nukes. Natural gas is the main dispatchable source, but all of the natural gas generators were affected at the same time.

Quote from GRMattson

Anyway wind and solar are off line a lot more than just about any other form of production of electrical power.

No, they are not. The capacity factor for dispatchable natural gas is 10%. It is 24 to 58% for old coal, 23 to 36% for solar, and 38 to 55% for wind. (Lazard) Of course you could run dispatchable gas or coal more than that, but you would be burning money for no reason. Every megawatt-hour from those sources costs far more than a megawatt-hour from wind or solar.

Besides, being off line a lot does not mean a source is expensive, unpredictable or unreliable. Solar is off line 12 hours a day after the sun sets. Everyone knows that. You can plan for it. You can plan for cloudy weather a week in advance. Despite being off line so much, solar is still the cheapest source of electricity overall. Also, it happens to be available at the highest power level when it is most needed, in sunny places where air conditioning is needed. It is not available at night, which happens to be when consumption falls by 1/2 or 2/3rds in most places.

If you tried to make a system entirely with wind and solar, storage would be a huge & expensive problem. As long as you still have many dispatchable generators, storage is not needed. Although, as it happens, battery storage may soon be cheaper than dispatchable gas. If that happens it would be most cost effective to make a lot more battery storage, and close down the peak gas units, or use them only 5% of the time instead of 10%.

Quote from GRMattson

So, switch to wind and solar and see what happens.

We know what happens. Power becomes so cheap, they give it away at night in Texas. The power companies execs see that it is far cheaper, which is why they are installing mostly solar and wind plants. Those people are not stupid, and they know how to count money. See:

Solar power will account for nearly half of new U.S. electric generating capacity in 2022

www.eia.gov

Of course you cannot switch entirely to wind and solar, for the reasons I explained above. You cannot switch entirely to nukes either, because you cannot turn them off. Switching entirely to natural gas or coal would uneconomical. It would make electricity far more expensive.

If wind and solar needed more backup power than coal or nukes, it would not be far cheaper, so your hypothesis that wind needs backup and other sources do not is incorrect. Whether something is run 10% of the time like peak gas, or 40% of the time like wind, or 95% of the time like a nuke, has no bearing on how much backup power you need. Since all three go off from time to time, you need 100% of their capacity in dispatchable power available to replace them when they are off. Whether it replaces them 90% of the time, 60% of the time, or 5%, you need the same amount of capacity. You have to replace the entire gigawatt of nuclear power when the plant has a SCRAM event (reactor trip).

The cost of solar takes into account the fact that the duty cycle is 36%. If the sun was out more than 12 hours it would be cheaper of course, but the sun is highly predictable, and that ain't going to happen. Unless you deploy a space-based solar power plant that delivers microwave energy to the ground. Which may actually be possible.

Quote from GRMattson

You can not predict with weather what is going to happen at any given time.

Yes, you can. That is what the power companies say. They probably know more about this than you do.