[mirko22]

More and more people are turning to Molten Salt Nuclear Reactors, like Liquid Fluoride Thorium Breeders, If Kirk Sorensen and others are right this will revolutionize energy (and probably not just energy but mining, water desalination etc.) as we know it unlike wind or solar ever could. Natural gas and coal should die once and for all as they are as dirty as it gets. I strongly believe we are ready for truly nuclear future.

[epistasis]

"more and more"

There's lots of talk, and boy would I ever love to see these actually happen!

However, there's stuff that a utility can design and install toady, and there's stuff that's decade out. For nuclear, deployment of "understood" designs can take a decade, easily.

The other thing about these new nuclear reactors, I don't ever hear anybody talk about them being much cheaper than current reactors. That should be one of the key selling points. They need to be cheap enough that they can run at, say, 50% capacity over the course of a day to follow the demand curve. Right now nuclear runs continuously at near maximum in order to be economical.

Wind and solar are getting cheaper. Storage is getting cheaper. These new nuclear technologies don't need to compete with natural gas and coal, they need to compete with the cost in 20 years of renewables with 30%-50% of that energy getting stored.

In any case, I'd love to see these technologies enter production so that we have a more diverse energy pool. But I don't think it does them any favors to pretend that they're further along than they actually are.

[Animats]

Molten salt reactors require an external chemical plant processing radioactive materials. Radioactive chemical plants are a huge headache. If anything goes wrong, there's a huge mess and another long-term toxic waste site. Hanford (a PUREX plant) and Pantex (in Texas) are both now toxic waste sites.

Every nuclear reactor design that has something complicated going on in the radioactive section has had serious problems. Gas-cooled reactors leak. (Ft. St. Vrain was so promising.) Pebble bed reactors jam. (The one in Germany is permanently jammed and can't be disassembled.) Sodium reactors have sodium fires. Ones with attached chemical plants have problems with handling of hazardous materials. It's discouraging.

Ordinary water-based reactors have a simple radioactive section. All the complexity is outside. Yet even those have problems.

Hyman Rickover on this subject:

An academic reactor or reactor plant almost always has the following basic characteristics: (1) It is simple. (2) It is small. (3) It is cheap. (4) It is light. (5) It can be built very quickly. (6) It is very flexible in purpose ("omnibus reactor"). (7) Very little development is required. It will use mostly “off-the-shelf” components. (8) The reactor is in the study phase. It is not being built now.

On the other hand, a practical reactor plant can be distinguished by the following characteristics: (1) It is being built now. (2) It is behind schedule. (3) It is requiring an immense amount of development on apparently trivial items. Corrosion, in particular, is a problem. (4) It is very expensive. (5) It takes a long time to build because of the engineering development problems. (6) It is large. (7) It is heavy. (8) It is complicated.

[Tade0]

There's one problem with nuclear that probably will never be overcome: it takes around 20 years from commissioning to the eventual connection of a nuclear power plant to the grid.

You can have an equivalent in solar, wind + storage in less than three years. That's 17 years of not producing electricity.

[Turing_Machine]

"You can have an equivalent in solar, wind + storage in less than three years."

A nuclear power plant can crank out 5 gigawatts.

There aren't any solar or wind plants of that capacity that were constructed in any amount of time, much less three years.

[philipkglass]

A utility scale solar farm can go from first concrete pouring to selling electricity in one year. And you can build a lot of farms in one year in parallel. For example, last year the United States installed ~10 GW of utility scale PV, mostly in farms under 200 MW each.

Based on EIA data, in 2016 the capacity factor of US nuclear power was 92.5%. Utility scale PV was 27.2% and wind was 34.7%: https://www.eia.gov/electricity/monthly/epm_table_grapher.cf...

Based on 2016 capacity factors you need to install a total of 17 gigawatts-peak of American utility scale PV or 13.3 GWp of wind to match the annual energy production of 5 gigawatts-peak of nuclear reactors. Last year the US completed about 10 GWp of utility scale PV and 8.2 GWp of wind (5.57 real annualized gigawatts, assuming same 2016 capacity factors going forward).

Storage, though? Nobody's going to install sufficient storage in the next 3 years that you could shut down the nearest reactor without burning more natural gas. Large scale storage is just starting to enter the mainstream.

[Turing_Machine]

"For example, last year the United States installed ~10 GW of utility scale PV"

So if a nuclear plant has 92% capacity factor, and a solar plant has 27%, that means a 5 GW nuclear plant would require about 17 GW of solar to replace it. In other words, there was less than 2/3 of a nuke's capacity of solar installations last year. Total. For the entire country.

[philipkglass]

"A nuke's capacity" -- not quite. There are only a handful of nuclear plants running with net capacity over 5000 MW. The largest nuclear plant in the US is Palo Verde: 3942 MW from 3 reactors. The sole reactor to enter operation in the US last year, Watts Bar 2, generates 1165 MW net: https://www.iaea.org/PRIS/CountryStatistics/ReactorDetails.a...

So multiplying capacities and capacity factors, for 2016 we get:

2016 nuclear: 0.925 * 1165 = 1078 MW

2016 utility PV: 0.272 * 10000 = 2720 MW

2016 utility wind: 0.347 * 8200 = 2845 MW

Last year's large scale wind and solar installations would be expected to produce as much electricity, annually, as 5 reactors like Watts Bar 2. Watts Bar 2 is pretty typical as far as capacity goes. The four new AP1000 reactors under construction in the US are each 1117 MW net, for example.

I personally hope that the US continues to build enough reactors to regain and maintain the institutional competence that was lost after the last wave of builds ended in the 1980s. Nuclear power has an excellent safety record, no air pollution, and is easier to manage at high penetration levels than wind/PV. But when I'm crunching the numbers I estimate that renewables will grow faster in North America for the foreseeable future; renewable projects scale down better, are cheaper per MWh generated even adjusting for capacity factor [1], and are much faster to go from first concrete pouring to first revenue.

[1] Cheaper per MWh than observed real-world prices for reactors currently under construction. Some older reactors can produce electricity at significantly lower costs.

[Tade0]

Last year China added 23GW of wind power.

Adjusted for the capacity factor that's over 5.75GW. Sure, it's not one plant, but quite possibly most of that capacity wasn't commissioned until 2013. Better still, they're just getting started with this.

The beauty of this power source is that it scales great - instead of erecting one 7MW turbine you can do that with any number of them, limited only by your budget.

Meanwhile it takes 5 years to construct a single 1GW block of nuclear and you can't just simultaneously start building another one next to it.

Nuclear won't win, because it's expensive and doesn't scale well.

[Turing_Machine]

"Nuclear won't win, because it's expensive and doesn't scale well."

https://en.wikipedia.org/wiki/List_of_largest_power_stations

I see several nuclear plants on that list, but not one solar or wind plant.

I think perhaps claims about the latter being "less expensive" and "scaling well" should wait until they've actually been economically operated at scale.

[matt4077]

Yeah, and fusion is just around the corner...

I wonder why the tech community has this infatuation with nuclear power. Ever since I registered my three-digit slashdot account, I've been reading exactly this post, just that the type of reactor people dream of seems to change every five years or so. Good to know it's "Liquid Fluoride Thorium Breeders", right now.

Meanwhile, solar power has lowered prices by a factor of 10 or so and is on a clear trajectory to beat fossile fuels on costs, without subsidies.

I'm suspecting there is something cultural going on here–maybe some instinct to seek out what others perceive as dangerous? Beats me...

[mikeash]

Solar and wind weren't all that practical until relatively recently (the past five years or so?). If you've been following this stuff a long time, nuclear really was the one hope for getting away from fossil fuels. It takes a long time for people's thinking to readjust once something like that changes.

[epistasis]

I've noticed that too, and though I think there's maybe a tiny bit of wanting to counteract the public perception of nuclear as more dangerous than other sources, I think that it probably has other tech related ambitions.

Science fiction commonly has nuclear reactors at the core of energy for space travel. For extremely long hauls it's compact in terms of volume and weight. As far as I can tell.

So nuclear has a history of being the "future." So tech-related people like it for that reason. We're not going to get personal jet-cars for transit either, most likely. But there's that hint of a dream in tech culture.

Any reasonable carbon-neutral energy plan that I've seen uses at least a bit of nuclear. It won't be the backbone, and it's unlikely that its performance characteristics or cost will change much, but the rest of the century will likely see a consistent amount of nuclear energy, given the longevity of existing reactors.

[Turing_Machine]

"I wonder why the tech community has this infatuation with nuclear power."

Because it works.

[dragonwriter]

> Because it works.

Not cost effectively, which is why even with existing protections from generally-applicable liability standaeds the industry demands greater direct subsidies and/or liability shields and without them has no interest in building new plants.

[Turing_Machine]

"industry demands greater direct subsidies"

Can you provide some examples of grid-scale solar or wind projects that don't get massive government subsidies?

[Turing_Machine]

Apparently the answer is no.

[crdoconnor]

"Yeah, and fusion is just around the corner..."

Fusion probably would have been if funding for nuclear fusion research had been kept at the same level as it was in the 70s. It took a deep dive after that though for reasons which most people can probably guess.

[_0w8t]

Fusion hit a technological barrier that only until recently meant extremely huge hard to build plants to have any hope of positive energy return. Those required many billions of investments just to study physics before any considerations of practical power plants.

Fortunately recent progress allowed newer designs that are much cheaper [1]. That is the reason that we got startups investing in fusion. It is still not pocket money, but at least the scale of investments is 1e8 USD, not 1e10 as before.

[1] https://www.google.no/amp/s/amp.theguardian.com/environment/...

[erikpukinskis]

A new generation of students who grow up doing math in VR will solve the plasma containment geometry problem, which is one of the major fusion hurdles.

[gph]

Just like a new generation of engineers doing math on computers would give us flying cars?

[erikpukinskis]

No, we don't need flying cars so that won't happen.

[ska]

"If wishes were horses we beggars would ride."

[erikpukinskis]

It's not a wish it's a prediction.

[tdb7893]

Are there any of these types actually created yet?

[mirko22]

One was created in 1960 and ran for 5 years but was shut down under Nixon administration due to various unrelated reasons.

But it was not creating fuel itself and it had some issue with corrosion which would have been fixed. There was not one built since and a lot of documentation was lost but luckily saved by NASA.

In last 10 years more and more people are working on them, specially India and China but also USA (Bill Gates is working on similar thing among others)

[ams6110]

More and more people? Who? Where are these reactor types being operated commercially for electric power generation?