“We will begin to revive and expand our nuclear energy sector, which I’m so happy about, which produces clean, renewable and emissions-free energy,” Trump said.

https://www.nei.org/News-Media/News/News-Archives/2017/Trump...

“We’ve already eliminated a devastating, anti-coal regulation, but that was just the beginning,” he said. “My administration is putting an end to the war on coal, going to have clean coal, really clean coal.”

“We will produce American coal to power American industry.”

In the speech now known as the "energy dominance" speech, Trump promoted fracking, nuclear, offshore drilling, and coal (including exporting coal).

ah yes the renewable nuclear

Backstory on the debate: https://en.wikipedia.org/wiki/Nuclear_power_proposed_as_rene...

Regardless, renewable is a less important concept than clean (how do you renew the sun which is a big nuclear reaction?).

The sun will burn out at a fixed time regardless of how much or little energy we harvest from it.

Assuming energy demand growth of 5% per year, we have enough land-based actinates for less than a century of energy usage in fast breeder reactors (if you prefer 2% annual demand growth, it's enough for about 2 centuries).

Seawater uranium buys you more time, depending on how you extract it, but hundreds of years and the sun burning out are two very different timelines.

Seawater uranium goes well beyond "hundreds of years." The oceans hold four billion tons of uranium, which in fast breeders would last many millions of years. On top of that, it's in equilibrium; as more is removed, more will dissolve from rocks. It really is at a timescale similar to the sun burning out.

A hundred years would give us plenty of time to develop alternative energy sources (fusion?). The fossil fuel age also last(s/ed) for about that long.

And how long will it take us to boil of the oceans (as in fusion) assuming 5% year over year increase?

How has energy consumption behaved before around the time of paradigm shifts and plentiful "free" energy?

Currently energy use is about 0.01% of energy that the sun sends us (if my googling is right). If energy use increases 5% per year, it doubles every 15 years or so, so after a hundred years we still use so little energy that it doesn't matter compared to solar heating. I think the oceans are safe.

And I'm all in favor of fission as a bridge-fuel to something more sustainable, but many people act as though it will last indefinitely, when it seems clear to me that it won't.

At current energy consumption, Thorium on earth is so able to power the whole planet for 100'000+ years.

Solar panels do also need resources to produce...

Also those two do not believe in global warming. (One thing nuclear does not cause)

It make take a long time for thorium reactors to come online but it is hard to believe anybody is going to fund the construction of a new large LWR anywhere outside China.

> (One thing nuclear does not cause)

However, two problems remain:

1) where to get the raw material? African mines are not exactly known for adhering to human or environmental rights, also African mines, by nature of being in Africa, don't create American jobs. Same is valid for the other major sources of nuclear fuel, all of which aren't the USA.

2) where to dump all the nuclear waste? I mean, people have debated to put in the most long-living and nasty stuff into special reactors to get it split up to less harmful stuff, but to my knowledge this has never been realized - and NIMBYs are highly afraid of a rad-waste dump near their houses, across the world. Also, no one has shown how to build something that can last over ten thousands of years while still protecting the rad waste.

The use of thorium in the MSR is perhaps 30x more fuel efficient than the current light water reactor. Large amounts of thorium have been buried in the desert by the U.S. government. Also, sufficient deposits exist in the U.S. to support centuries of use.

As for nuclear waste, the real reason why the problem appears intractable is that nuclear waste is not waste.

The LWR gets only 2% or so of the energy in uranium, the same fuel could be reprocessed and used in fast breeder reactors to release the other 98%. In fact, it is the presence of plutonium and other actinides in spent fuel that requires environmental isolation beyond 500 years or so. If we use those actinides as fuel, they do not need to be buried, and if we do that, the volume of waste is vastly reduced along with the half-life.

The fast breeder/reprocessing route has not been commercialized as of yet for a number of reasons. Probably the most discussed is that plutonium, neptunium and other actinides useful for nuclear weaponry could be nicked from the reprocessing plant.

The thorium MSR is an alternate path to a breeder, aka a "thermal breeder". In the case of the MSR, the reprocessing is done online or nearline to the reactor. It is also possible to do thermal breeding with thorium with a modified version of the light water reactor. Reprocessing that is a bitch though...

The most immediate problem facing the industry is an inability to say "it is going to take X years and Y dollars to build a reactor" and then finish it somewhere near on schedule and on budget. Being over 10% would be no scandal, but it is still looking more like 10x than 10%.

Doesn't reprocessing produce a lot of high level waste as a byproduct, thereby worsening the waste problem?

And I understand the Japanese had an experimental breeder reactor for a long time and never achieved actually producing any commercially viable electricity. They did get lots of plutonium, though, which may be turned into bombs any moment.

Early on the fission products were stored in acid solutions in tanks. Circa 1980 the technology was developed to evaporate the solution and trap the fission products inside glass.

Plutonium from either a LWR or FBR fuel cycle is heavily contaminated with isotopes that will cause a bomb to predetonate or get really hot. Somebody with advanced technology (say Japan's government) could probably use electromagnetic separation to remove the unwanted isotopes, but you wouldn't expect ISIS to be able to do it.

The real thing terrorists would want to nick from a reprocessing plant is Neptunium 237; it has a large critical mass compared to plutonium, but it can be separated by chemical means and will not predetonate.

In the 1970s people wrote hang-wringing papers wondering if inventory control could be made good enough to detect diversion, a 2000s accident at Sellafield's THORP plant showed that it probably can't. They lost an Olymptic size swimming pool worth of fluid containing upwards of 50kg of Pu and around 1000kg of U and did not notice for months.

To be fair, it drained into a containment area and did not threaten anyone. They were able to clean it up. But obviously the inventory control was nonexistent.

THORP has been successful at producing plutonium oxide powder but the UK was unable to fabricate it into fuel elements and had to ship it to France.

Reprocessing separates rapidly decaying fission products from slowly decaying transuranics. The transuranics go back in to be burned, the fission products decay comparatively rapidly.

Great that thorium is progressing. I predict the debate about global warming will disappear once we have new power sources in place. Those who denied global warming will suddenly acknowledge it; those who berated the deniers will move on to other issues.

You have way too much hope for the internet to not shit post.

Hinkley C