> (nuclear does also have the ability to do variable loads like these. For some reason people think it can't...)
Nuclear power is too expensive to leave idle capacity on standby.
Nuclear power is too expensive to leave idle capacity on standby.
People think waste is the biggest problem with nuclear, but I think it is huge capital costs and lack of flexibility are even larger problems (not to mention insurance for accidents, but only the government can provide that). Coupling nuclear with some kind of large scale battery would work to even out load requirements, but the only thing that might work is pumped storage, which would require a huge reservoir at a decent elevation, not to mention being pretty inefficient.
Most high fuel efficiency designs are fast reactors, or they employ extra radiation source to "burn down" the fissile material.
The first is that it gets you out of needing ordinary batteries, because instead of converting heat to electricity to batteries and back, you can take the heat generated by the reactor during the day, store it in an insulated vat of molten salt and then use that to drive turbines at night. This should be much cheaper than ordinary batteries because expanding storage capacity only requires having more salt in more vats, and salt is much less expensive than lithium batteries.
The second is that if you have a nuclear reactor for generating at night when solar doesn't, the incremental cost of also operating it during the day is lower than the solar generating cost. It can't recover its full fixed costs at the price of daytime solar, but as long as it can recover its incremental cost you still operate the reactor 24/7.
Moltex claims that interposing a salt store would allow these components to be made to non-nuclear standards, but as far as I know no regulator has agreed with that.
"Unproven" is a synonym for we haven't done it yet, so the only way to prove it is to build them, so building them is the solution to that rather than a problem that should prevent building them.
And if the only problem is regulatory but there isn't actually any reason not to allow it, this too has an obvious solution.
The justification for treating the cooling system as part of the reactor presumably comes from older designs where the active cooling is necessary for safe operation. For newer passively-safe designs, what happens to the heat once it's removed from the reactor wouldn't matter any more than what happens to the electricity once it's removed from the reactor.
And all that means that new reactor technologies are not going to be really available for decades, and will be competing not with renewables and storage now, but the renewables and storage that will be available for purchase decades hence.
Tax subsidies for renewables, at least in the US, are small compared to the levelized cost difference with nuclear.
If you look at Lazard's levelized cost of energy report, where wind is far cheaper than nuclear, they assume a 20 year lifespan for wind turbines. This is not unreasonable.
Operating costs aren't so bad.
Capital costs for building nuclear reactors have gone up over time. That's partially to pay for necessary improvements to safety. But mostly down to double standards that require much higher standards in nuclear than other sources of power.
For example, coal plants release orders of magnitude more radiation than nuclear plants.
Well yeah, nuclear plants don't release much radiation when there are no accidents and the waste is safely contained. But very often the waste isn't contained properly, and sometimes there are accidents. These events release a lot more radiation than coal plants.
Unless you have data that supports this statement, I'd state the opposite. It's easy to think nuclear accidents release a lot of radiation, but the actual accumulated dose from nuclear power (including accidents) for the average individual over time is very low. Coal, on the other hand, continuously spews out radioactive ash in large quantities.
Granted, other sources of radiation (radon, cosmic rays, medical x-rays, etc.) are a lot larger, but if comparing the two I'd guess coal is the larger culprit even when including nuclear accidents.
This is only because nobody's living in nuclear disaster zones. If people were carrying on their daily lives in the Chernobyl or Fukushima then their accumulated dose would be much much higher.
As you say, the levels from coal are small enough that other naturally occurring sources are more significant, and thus it has little practical effect on people's lives. On the other hand, nuclear accidents take large areas of land out of use for time scales long enough that they effect several generations.
(It might very well be economically the best for them. But making that judgement requires more context.)
We create these problems for ourselves. Legal challenges are the number one cause of construction delays.
See for example:
* https://www.scientificamerican.com/article/coal-ash-is-more-...
We have a vicious cycle involved here, where old (if made safer) designs that can't load-follow are the only option, due to lack of funding for newer tech (like, late 1970s tech). At the same time the limits we put on nuclear mean that not only regulation-related costs are huge, reactors are made pretty much on one-off or very limited series basis, meaning we don't benefit from any kind of benefits of serial production, including better QA.
There are load-following small, modular reactors (adapted from nuclear submarines) that will even self-seal in case of rupture and that promise the option of just transporting them on trailer car. They languish in design bureau due to issues in getting funding to start even a demo plant in present political climate. China is helping move the tech a bit forward, but that's not enough.