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Why nuclear energy is our best option at the moment

energyrealityproject.com

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

#321

Post by jpgvm »

InclinedPlane wrote: post #260
neltnerb wrote: post #238

Earlier quoted context omitted.

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…

Hastelloy-N, it's expensive stuff but it works. Corrosion is one of the difficulties of molten salt reactor designs, but it's manageable with the right materials. And the tradeoff is that you don't need an enormous high-strength containment vessel (because everything radiological is at 1 atm), you don't need to pump water into the thing constantly to avoid "really bad things" happening (Fukushima), etc, etc.

Exactly this.

Specifically you should read the findings of the MSRE (Molten Salt Reactor Experiment) at ORNL.

Wikipedia has a relatively laymans explanation of the state of the Hastelloy-N when the experiment concluded.[1]

It's worth mentioning Hastelloy-N isn't that expensive all things considered. It would probably come out to a small percentage of the reactors total cost factoring in R&D expenditure etc.

[1] https://en.wikipedia.org/wiki/Molten-Salt_Reactor_Experiment...

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

#322

Post by Uberphallus »

mixmastamyk wrote: post #290
chc wrote: post #215

Earlier quoted context omitted.

A sibling commenter already did run the numbers on it, and found nuclear ahead by a factor of 10: https://news.ycombinator.com/item?id=10503382

Considering that no one will want to live near it, and not allow it to be farmed either, such plants aren't as space efficient as they might seen.

Then cover that "unwelcoming" area with solar panels. Win-win.

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

#323

Post by danieltillett »

epistasis wrote: post #222
david-given wrote: post #208

Earlier quoted context omitted.

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.

The electrical grid will be upgraded, it's not static. Heat is easy to switch to electric. Short transport will move to electric. Longer haul transport is more difficult, but liquid fuels can be generated from CO2 in the air or water (at somewhat large expense). However, if there is large amounts of overcapacity, then liquid fuel generation via electricity might become economical.

Isn’t the solution to long haul transport electrification of the rail network? An alternative would be a swap and go battery network for the road system. The nice thing about a swap and go battery network is we have storage to even out demand and production.

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

#324

Post by RobertKerans »

Retric wrote: post #307
Turing_Machine wrote: post #275

Earlier quoted context omitted.

Of course, pumped storage (or any kind of hydro) is many orders of magnitude more dangerous and environmentally destructive than fission. The Banqiao Reservoir dam failure alone killed over 170,000 people and made over 11 million homeless. I worry far more about the hundreds of millions of people living downstream of the Three Gorges Dam than I do about people living near fission plants.

That dam failed when 1 year's worth of rain fell over 24 hours if it had not been there a lot of people would have died anyway. On net Dams have saved far more than 170,000 lives in china alone. Flood control is more or less a necessity in the modern world adding energy generation on top of that is a minimal risk. ex: From 1998 https://en.wikipedia.org/wiki/1998_China_floods loss of 4150 people, and 180 million peopl…

I get that it's important to be objective, to look soberly at costs and benefits. But 'only' 26,000 direct deaths? Oh, that's fine then.

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

#325

Post by tempestn »

barney54 wrote: post #298
paulsutter wrote: post #272

Earlier quoted context omitted.

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 a technical issues--nukes are limited in the amount they can load-follow. But winds cannot load follow at all and solar can help some, but doesn't necessarily help cover peak daily load. For example, yesterday in California the system peak load was at 5:49 pm, but solar PV peak was at 9:44 am. data: http://content.caiso.com/green/renewrpt/20151102_DailyRenewa... Nukes aren't great for load following…

Another possibility would be to add massive storage to the grid. Maybe it's pumped hydro or this kind of thing: https://news.ycombinator.com/item?id=8646787. Or perhaps more realistically, if someday soon there are millions of electric vehicles connected to the grid at any given time, especially during current off-peak hours, that storage could be leveraged for load shaping.

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

#327

Post by ars »

yk wrote: post #303
anon1mous wrote: post #119

Earlier quoted context omitted.

Do you burn it? Why is it than that every reactor I know of, in US, WE, Japan, stores tones of extremely dangerous waste on site?

Because burning it involves superheated, radioactive phosphoric acid.

What are you talking about? No it doesn't.

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

#328

Post by ars »

anon1mous wrote: post #284
ansible wrote: post #125

Earlier quoted context omitted.

I think brrt is talking about "burning" nuclear waste in a molten-salt reactor or similar. Some types of existing fission reactors can only utilize a small percentage of the uranium in their fuel rods, after which the rods must be removed. The rods must then be stored, and possibly reprocessed afterwards. MSR and other fission reactor types can utilize 100% of the fissionable material put into them, so this sort of l…

Yeah, so there is a solution to nuclear waste - in fantasy land.

It's called a breeder reactor, they are quite common in some places (but not in the US). I guess those places are "fantasy land"? Pretty cool since I can visit them.

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

#329

Post by olau »

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…

The real problem is that to get anything resembling economical use out of a nuclear plant, you need to output 100% almost all the time. New plants are too damn expensive to just let them sit there.

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

#330

Post by sandGorgon »

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…

china is betting big on liquid fluoride thorium reactors. http://blogs.telegraph.co.uk/finance/ambroseevans-pritchard/...

China’s thorium project was launched as a high priority by princeling Jiang Mianheng, son of former leader Jiang Zemin. He estimates that China has enough thorium to power its electricity needs for “20,000 years”. The project began with a start-up budget of $350m and the recruitment of 140 PhD scientists at the Shanghai Institute of Nuclear and Applied Physics. It then had plans to reach 750 staff by 2015, but this already looks far too conservative.

http://blogforarizona.net/could-thorium-reactors-provide-the...

Paradoxically, though, given thorium’s history, it is the difficulty of weaponising thorium which many see (as it were) as its killer app in civil power stations. One or two 233U bombs were tested in the Nevada desert during the 1950s and, perhaps ominously, another was detonated by India in the late 1990s. But if the American experience is anything to go by, such bombs are temperamental and susceptible to premature detonation because the intense gamma radiation 233U produces fries the triggering circuitry and makes handling the weapons hazardous. The American effort was abandoned after the Nevada tests.

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