Comment by cm2187 | Hacker News Reader

Comment by cm2187 | Hacker News Reader

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The only problem with nuclear energy is the Chernobyl / Fukushima risk, which even as a supporter of nuclear energy I find unacceptable. Human nature being what it is, nuclear plants are bound to be run sooner or later by idiot, careless people. Uranium-based nuclear energy is not idiot-proof.

I have great hopes on Thorium. I am by no mean a specialist but I understand it has all the benefits of uranium for civil nuclear energy except that it uses a design of nuclear reactors that can be stopped in seconds, and rely a lot less on high pressure (i.e. subject to blowing up) pipes.

But it will take huge investments to develop the whole supply chain and all the associated technologies. It would make sense for a country or a group of countries who would want to develop a new nuclear park to team up and just bite the bullet. China would be a good candidate. But also the vast majority of the nuclear power plants in Europe and the US are more than 30y old. Might make sense to just do it, go clean, safe and stop writing checks to our "friends" in the middle east...

There is nothing about thorium that makes it able to be stopped immediately or run at much less pressure. There are reactor concepts that run at lower pressure and have passive safety when shutdown, but they could use thorium or uranium just the same.

Thorium reactors have to be part of a closed nuclear fuel cycle meaning you have breeder reactors combined with fuel reprocessing. No nation seriously does this right now because when you reprocess you can easily separate bomb materials (although India is allegedly moving towards a closed thorium cycle). Reprocessing involves nasty chemicals that are super radioactive too which is another step where things can go very wrong.

Also, thorium can't even run a reactor by itself. It has to be used as a feed material to breed Uranium-233 by absorbing neutrons and decaying, so at the end of the day you are still using uranium to produce power. The only advantage of thorium is that it doesn't produce as many actinides which are the really long-lived radioactive waste products. So after thousands of year the radiotoxicity of your waste is less with thorium than uranium.

I'm pro nuclear. I like thorium, but it would realistically require a nation to step up and invest trillions of dollars in the infrastructure and licensing only to have things rolling along decades later. Although, it would provide energy for a few centuries if done well.

I understood that thorium was used in liquid form (molten salt) which you can separate a lot faster than a reactor using fuel in a solid state and that way stop the reaction.

Perfect is the enemy of good. If once every 20 years an accident happens and then 20 years after 20k people get cancer, that is an acceptable loss. And its' not even clear if Fukashima will be that bad. Right now the estimated deaths are going to be zero.

You still have entire regions in ukraine and belarus where you can't grow anything that can be consumed.

I would agree with any other industrial accident. But the reality of nuclear accidents is that you end up polluting at the scale of a country. That's a big Damocles sword to live under.

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