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Comment by aout | Hacker News Reader

So ok, the website is cool and the technology is said to be something like 99.9999% better. This might be a stupid question but I'm no nuclear engineer not a specialist about chemistry or physics but I wonder why a such "beautiful" idea would not be already used.

I've read the related wikipedia article about Molten Salt Reactors and I understand there are several problems about the technology: mostly corrosion and embrittlement.

So now I find myself asking this: did they fix those problems? The website copy suggests so. Can somebody explain how? I couldn't figure it out.

edit: clearly the team and company have quite legit credentials, MIT nuclear department etc... they must know what they're talking about. I just want to know if they've given details about the solution.

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Probably the same reason Germany shutdown its power plants after Fukushima. Despite Fukushima being a huge success story [1] some people are scared, some unthinking, almost all irrational and unable to handle probability at all. Nuclear power seems magical and shares a word with scary weapons. It's not "natural" for mediocre definitions of natural.

1: Seriously. Fukushima did everything wrong. Huge earthquake and tsunami. Older design. Then they tried to cover stuff up. And the repair crews showed up with wrong equipment. More denial. And all that with no loss of life. Just a bit of "lost" land for a while, and extra costs. So many people freak out about it, but that US carmaker with the stupid ignition killed more people and we aren't giving up cars. Fukushima screams "hey, wee couldn't fuck this up, even given perfect conditions and terrible management". But hey, why take a rational approach when you can " go green ".

The only thing that went right with Fukushima was the wind blew the radio isotopes over the pacific (mostly) and the rest of the stuff that leaked out went into the ocean. People would be singing a different tune if the wind blew all that stuff on shore. Quite a number of nuclear plants are located in places not so fortunate. For instance consider the location of three mile island, located well inland on the Susquehanna River. If you had a containment loss at three mile island, it'd be a big big mess.

People say these plants are all safe, and newer plants are safer, but the near catastrophic failures don't give one a warm feeling. The one that stands out to me was pin hole corrosion through the cladding on the top of a reactor vessel. That lead to a large cavity corroding unnoticed in the mild steel. Which which was discovered when someone noticed an odd budge in the top. if that had failed, you would have had total loss of cooling and a melt down.

Agreed. BTW my old boss said the same after Chernobyl: he used to be worried about nuclear safety, but after Chernobyl, where everything went as much wrong as it can go - you have an unsafe type of reactor, incompetent staff blows it up, the accident is covered and evacuations are delayed, etc - and still the death toll is much smaller than the impact of coal mining, which is the practical alternative picked by e.g. Germany after Fukushima.

it's overwhelmingly not coal, a majority share is imported gas. Local energy is coal and renewables are under 5% last time I checked, that's true.

Fair enough, though gas imports from Russia have their environmental and human impact, too (up to and including a war in Ukraine, as the country is an inconvenient obstacle for cheap overland pipelines if it is not under Russian control in the way it was with Yanukovych).

BTW I find it somewhat scandalous that Russian gas companies can hire senior politicians (such as former German chancellor Gerhard Schröder and Finnish prime minister Paavo Lipponen) to assist the political approvals. Although these men are no longer in such official positions, it is obvious that they were given money to advance the interests of Северный поток through their connections in their respective social democratic parties.

Doesn't it take a while for people to die or see effects from radiation exposure (unless it's extreme?). Is there a reason to suspect that we won't see problems from what happened?

Also having land uninhabitable for thousands of years weighs pretty heavily even if the risk of failure is low.

They originally said it'd be a few years, but the JP government is on behind, so it might take longer to decontaminate. I don't think anyone is talking more than a decade or few. Countries sell land, so think of it that way, at worst. The clean up is also super expensive. And, over 1000 people died from evacuation-related issues. I guess that's just a factor when you move older people around, for any reason. So, yes Fukushima sucked, but in context, given the incompetence, it seems very encouraging. Unless we act even more stupid and get a large disaster, why would it be worse?

From what I've read, the estimates of cancer are really low. But you're right, there might be a few directly related deaths over the next several decades.

You'd think this would result in an attitude of wanting to push newer designs and so on, but running away is a more human reaction, it seems. :(

> over 1000 people died from evacuation-related issues.

As if the fact that a very very large tsunami hit a densely populated area did not have an impact.

Of course, a lot of people were killed by Fukushima - due to the shutdown of other nuclear reactors, which necessitated reducing electricity consumption, i.e. turning off A/C in buildings, effectively killing lots of old and weak people.

It's not thousands of years, though it will likely be a few hundred[1].

[1] http://www.theglobeandmail.com/news/world/area-around-cherno...

People who believe that nuclear reactors are so great and safe can probably save a lot of money by renting property next to a nuclear reactor. Have you done so? Would you like a reactor to be built next to your house?

I have actually lived half a kilometer away from a nuclear reactor. I didn't think twice about it. Itwas a small research reactor at a university campus, of course, but nevertheless, the reason I wouldn't want to live right next to a big energy production reactor is not that I would be afraid it blows up; it's that the plant is a very big building that involves a substantial amount of people, materials and security measures nearby.

That is why it makes sense to build the reactors slightly away from population centers. Not to protect the population, but to avoid annoying it with the presence of a huge energy factory.

Would you rather live right next to a coal plant? They release a lot more radioactivity into the air that a nuclear power plant. Plus, you know, all the other pollutants that they blow into the atmosphere.

Well at least people readily live next to solar power cells and even install them on the roof of their houses. Not claiming it is the solution for everything. But coal and nuclear power are not the only power sources (energy efficiency is another approach).

From my understanding it comes down to part politics, part feasibility. When nuclear power first started becoming popular light water reactors were easier to make and their fuel/byproducts aligned with the production of nuclear weapons. As years went on regulation and inertia did a great job of cementing us into our old ways. Today, advances in (material) science have made producing molten salt reactors more feasible. They also seem more attractive now that the public is generally very adverse to nuclear waste and power plant failures. I'm paraphrasing what was explained to me so someone that knows more please chime in.

Kirk Sorensen has been a major advocate of molten-salt reactors and gave a great Google tech talk on the subject. https://www.youtube.com/watch?v=bbyr7jZOllI

Because nuclear weapons aren't a byproduct of this kind of reactor, and that renders it useless in the eyes of politician-warmongers.

That was more true in the 60's, and so we never spent the time to try bringing this to production. We don't need to make all of our nuclear reactors capable of producing weapons-grade material anymore, and I don't think there's much objection to new reactor types on those grounds.

Actually it was never true, but it makes a good story. Sorensen in particular claims the fast reactor program was favored because of its weapons applications. Nothing could be further from the truth. Fast reactors, from their conception, were pursued for sustainability reasons by pacifists like Zinn. The first electricity ever produced from fission was produced by EPR I. Every single gram of fissile in the world's nuclear weapons was made in a thermal reactor or enriched from ore. The MSR program was cancelled along with myriad other programs during the early-70's recession... including the nuclear rocket programs, the Apollo program, etc.

There has never been an economic case for the breeder simply because the fuel cycle is such a small part of the cost of nuclear energy. When you have a factor of 5,000,000 you can afford to throw away a factor of 100.

Natural gas plants don't produce weapons material either, and we're building plenty of those.

The weapons material we do produce comes from specialized reactors, not civilian power plants.

I'm assuming the "Molten Salt Reactor" method is the same principle as the "Sodium Reactor" that was experimented with around 50 years ago?

[0] https://en.wikipedia.org/wiki/Sodium_Reactor_Experiment

Sodium reactor is an example of https://en.wikipedia.org/wiki/Liquid_metal_cooled_reactor. Molten salt seems to be a different type https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment

The ambiguity of "salt" is unfortunate here. The "salt" in "molten salt" is a salt, but not table salt (so, no sodium). The one proposed here is a lithium fluoride/uranium fluoride salt. Conversely, while table salt has sodium in it, the sodium in the sodium reactor isn't part of table salt, it's pure sodium metal. (Turns out they explode, also, so there's not much enthusiasm about them anymore.)

The Sodium reactor is a standard solid core Uranium fueled design that uses liquid sodium as a coolant.

The molten salt design is completely and utterly different. In a molten salt reactor the fuel itself is molten (in salt form), which turns out to offer a variety of benefits.

In the "what's next" section it indicates the next step is more lab experiments. So, I'd guess that they have quite a bit of work ahead of them.

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