Why nuclear energy is our best option at the moment • Hacker News Board

Re: Why nuclear energy is our best option at the moment

#331

Post by nicobn » Wed, Nov 04, 2015, 7:12 AM UTC

dredmorbius wrote: post #316

nicobn wrote: post #314

Earlier quoted context omitted.

Fuel is a minuscule percentage of the cost of building and operating a nuclear reactor. The cost of uranium is currently about $90/kg. Citing a previous poster, around 70 MT of uranium is used every year, which comes to about 6.3 G$, which comes to about 2.61 $/TWh. As per the NEI, the cost of nuclear energy is 108 $/TWh. At current prices, uranium accounts for 2.4% of the cost of producing nuclear energy. Keeping th…

The cost of everything else about a nuclear reactor is based in hugely understated fossil-fuel subsidised cost basis. That is going to inflate when you don't have those fossil fuels around, particularly for elements for which hydrocarbons are essential inputs or exceptionally difficult to substitute (coking coal for steel, much or all transport, chemical feedstocks, industrial process heating). But that's less a conc…

I definitely agree with you; the externalities of nuclear power are very often understated.

Re: Why nuclear energy is our best option at the moment

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Post by sooheon » Wed, Nov 04, 2015, 7:26 AM UTC

_urga wrote: post #319

A nuclear researcher from iThemba Labs gave a talk at University of Cape Town shortly after the Fukushima accident. 1. During his talk, he mentioned that nuclear plants are designed to have a very low probability of Chernobyl-scale failure, and that the current rate of Chernobyl-scale failure given the number of nuclear plants in production is roughly 1 every 20 years. 2. He eventually concluded his talk by saying th…

I'd still take 1 Chernobyl every 10 years over breathing Beijing air every single day of every year.

Re: Why nuclear energy is our best option at the moment

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Post by Asbostos » Wed, Nov 04, 2015, 7:32 AM UTC

mixmastamyk wrote: post #287

pjc50 wrote: post #100

"We could do it for $1 Trillion with liquid-fueled Molten Salt Reactors, on the same amount of land, but with no water cooling, no risk of meltdowns, and the ability to use our stockpiles of nuclear “waste” as a secondary fuel." This is not a production-ready technology, though. I believe there are lingering problems with corrosion. And the claim that the MSR doesn't require secondary water cooling is odd: what's the…

Molten sodium was at the heart of the Santa Susana nuclear disaster in southern California, which was covered up for fifty years. Needless to say, I'm skeptical.

Vaporized sodium is at the heart of nearly every streetlight. They're not causing disasters. Just having the same material doesn't make the safety the same.

Re: Why nuclear energy is our best option at the moment

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Post by davedx » Wed, Nov 04, 2015, 7:39 AM UTC

david-given wrote: post #208

brrt wrote: post #45

Actually, renewable energy is, when you actually run the numbers in a sensible way, pretty cost effective: http://www.sciencedirect.com/science/article/pii/S0378775312... - this finds that with 90% solar/wind and modest amounts of storage, electricity would be cheaper in 2030 than it is today, and that the cheapest option is actually a vast overcapacity. There are plenty of flaws with that article, but still less tha…

Just a reminder that energy use and electricity use are not the same thing --- about 2/3 of all energy is used for heating and transport, and electricity can't be used for that. (Because it's too hard to store, and because the electrical grid simply can't transport that much.) Sure, solving renewable energy is a really valuable thing to do, but it's still only solving 1/3 of the problem.

> 2/3 of all energy is used for heating and transport, and electricity can't be used for that

Well, here in the Netherlands, the majority of the trains will soon (2018) be powered by 100% wind energy. 50% since this year.

So it's categorically (and I would think obviously) incorrect to say "you can't use electricity for transport".

http://www.ns.nl/over-ns/campagnes/maatschappelijk-betrokken...

Heating is another question entirely. You have more of a point there -- it's hard to find an alternative to natural gas for heating.

Re: Why nuclear energy is our best option at the moment

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Post by Asbostos » Wed, Nov 04, 2015, 7:39 AM UTC

merb wrote: post #202

RealityVoid wrote: post #174

Earlier quoted context omitted.

I seriously doubt that claim.

it's true. somewhat. I mean the energy of the nuclear station stays constant. however the peak power of the solar panels will be higher. but I doubt that the solar panels will still be creating less energy over a longer period of time. unless you build both inside a desert and there you would have other problems like the sand which affects the lifetime of your panels, etc.. btw. i'm against nuclear and non renewable…

What's wrong with non-renewable? That simply means it won't last forever. Is it really important that whatever energy generation we use can be repeatedly maintained and operated forever? I don't see any problem in making the most of the Earth's uranium resources while it's cheap enough. In the worst case, we'll just have to stop doing that later rather than sooner.

Re: Why nuclear energy is our best option at the moment

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Post by PolLambert » Wed, Nov 04, 2015, 7:59 AM UTC

jandrese wrote: post #150

PolLambert wrote: post #83

Earlier quoted context omitted.

The reverse is actually true. Nobody uses Thorium since you can't make bombs out of them. Thorium is very unsuited to weaponize since one of the byproducts of the fuel process (U-232) decays in to a hard gamma-emitter. This not only makes the material dangerous to handle, it will also wreak havoc with bomb electronics, will require heavy shielding and be very easy to detect. Due to its unsuitability for bombs , the m…

Emitting hard gammas seems like it would be troublesome for a power plant as well.

A nuclear power plant has thousands of tons of shielding. There are also no timing critical electronics sitting right next to the fuel.

Re: Why nuclear energy is our best option at the moment

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Post by Eeko » Wed, Nov 04, 2015, 8:02 AM UTC

kuschku wrote: post #279

Eeko wrote: post #188

Earlier quoted context omitted.

It's not supposed to dilute. It should stay put and not spread around. Most human activities tend to displace natural ecosystems. Waste dumps (nor windmills) are no exception. The question is, is the damage lesser than greater than in proposed alternatives? Though I do not understand why did they choose to dump the waste to the channel? If I would dispose the waste by sinking, I would use a kilometers deep trench to…

Well, they did it because it was easy. And cheap. If you want safe nuclear power, including demolishing the reactors safely, safely getting rid of all the materials, nine nines safety, etc, then it won’t be profitable. If you want for-profit nuclear power, then either the government has to subsidize it, or it has to be unsafe. Usually, it’s both unsafe (companies save money everywhere, including stuff like not securi…

Depending on the definition of "safe". Digging a long hole to the ground, towing an old to-be-demolished barge on top of Mariana's trench etc. is not that expensive.

The hard part right now is deciding on suitable ground for the tombs. Doing seismic measurements, analyzing the rock formations and especially forming the policies for burial (e.g. do we reserve the option to dig the stuff back up for use in breeders?) can take decades, but it's hardly an expensive part of the process.

The disposal isn't really an acute problem that needs to be solved today. It's not that dangerous to store the junk at warehouses while we use hundred years if necessary to research best viable options.

Nuclear power is expensive, but only if you compare it to burning hydrocarbons and hydroelectric power generation. It's still decades ahead of photovoltaic and wind turbines.

Re: Why nuclear energy is our best option at the moment

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Post by kgarten » Wed, Nov 04, 2015, 8:05 AM UTC

I wonder why hacker news is so positive on nuclear power. The article is full of false information or misguided information. I always recommend "Into Eternity" to understand why nuclear is one of the worst options for eternity ;) https://en.wikipedia.org/wiki/Into_Eternity_(film)

Re: Why nuclear energy is our best option at the moment

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Post by PolLambert » Wed, Nov 04, 2015, 8:06 AM UTC

paulsutter wrote: post #272

yazriel wrote: post #187

The article is completely unprofessional. The tone itself is very one-sided - which is bad enough. However, the factual omissions are ridiculous. Here are a few examples: the area used for wind turbines is large, but it is usually re-usable for agriculture, or increasingly off shore official nuclear death are low - but there is a lot of dispute on the "long tail" of long term deaths from the big nuclear disasters of…

Could you clarify the "huge problem of load-following" for nuclear power plants? My understanding is that it's mostly a licensing issue rather than a technical issue, and in practice hasn't had a big impact on CF[1] [1] https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-lo... "Most of the currently operating Generation II nuclear reactors were designed to have strong manoeuvring capabilities. Nuclear power pla…

Load-following is both license and technical related in a chicken-and-egg-way. You need to incorporate load-following into your reactor design. More specifically: the speed with which a reactor can modulate its output while staying within nominal operational bounds is a design parameter. If licensing doesn't allow load-following, you're not going to give your reactor that feature.

Re: Why nuclear energy is our best option at the moment

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Post by Gibbon1 » Wed, Nov 04, 2015, 8:10 AM UTC

neltnerb wrote: post #238

InclinedPlane wrote: post #171

Earlier quoted context omitted.

Corrosion is not a problem. But there is still a ton of work that needs to be done with molten salt reactors. But it's work we should do, I feel. I used to be skeptical of the idea but after doing a considerable amount of research I changed my opinion, the core design has a myriad of advantages and it's practically criminal we aren't dumping gobs of money into research for it. As for water, the working fluid of the h…

Wait wait wait, you're going to have to provide a citation for this claim that corrosion is not a problem. I was told by faculty with joint appointments in matsci and nuclear engineering that it is a major issue and that while they've developed some alloys that look reasonable in the recent past it's still academic research unproven in scale up. Holding molten salts is really hard... they corrode the heck out of even…

I know not much about material science, except for some very painful experiences in an industrial setting+. But I have a feeling people tend to think fluoride salts are going to be as docile when molten and exposed to a high radiation flux as they are as room temperature solids.

+ Ethylene-oxide gas + moisture + heat -> plying rough trade on supposedly compatible materials.

Not my problem but a customer I worked with had a gamma ray sterilization unit. There were some limit switches which they needed to replace after ten years. Replacements, same part number, manufacture swore up and down they were identical, would crack after three to six months.