Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why nuclear energy is our best option at the moment

energyrealityproject.com

Post reply on HN
Print view View original

51–60 of 393 posts

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

#51

Post by Eeko »

tomcam wrote: post #21

I am not reflexively anti-nuclear. However, I have never heard a satisfactory answer to the simple question: "How do we store nuclear waste safely?"

Dumping it to the ocean is pretty safe. Seriously: https://en.wikipedia.org/wiki/Ocean_disposal_of_radioactive_...

However, since people don't easily believe water's a very effective radiation shielding (even if there's an xkcd of it https://what-if.xkcd.com/29/) and that heavier than water metals kind of tend to stay put at the bottom of the ocean, other means of disposal might be more realistic. Recycling in breeder reactors, digging huge holes to the ground, buildings which last longer than pyramids etc.

Of course, how one defines "safely" is tricky. Perfect safety is impossible, of course. One can't guarantee that our hole will stand to the heat death of the universe - but just ensuring that the disposal will cause less harm to earth and its living beings than any other energy production method is fairly easy to do. Even windmills kill some people, animals and fauna during normal operation, so if we set "less murderous than windmills" as an acceptable safety standard, we could settle for the ocean disposal, for example.

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

#52

Post by PaulHoule »

mbil wrote: post #19

I don't know anything about nuclear energy, but a friend who works in nuclear tech told me that the reason thorium as an energy source hasn't been embraced is because its byproduct can be used for weapons. That doesn't look to be exactly accurate (based on a few minutes of googling), but there might be some truth to it. http://phys.org/news/2012-12-thorium-proliferation-nuclear-w...

U233 can be used to make bombs, but when you make U233 in a reactor, the progenitor to U233 is Pa233, this has a half life of 27 days. Inside the reactor, Pa233 gets hit by neutrons and one of them will knock another neutron loose so you get Pa232, then you get U232.

U232 makes a very heavy gamma ray that makes it difficult to work with the resulting U233, that is, you get killed trying to make a bomb from it. Also the fabrication of solid U233 is difficult because of the U232 contamination.

If Thorium is used in an LWR the neutron exposure on the Pa233 is enough that the U233 produced is hard to work with. If you had a special reactor like the ones they use to make weapons grade plutonium you could make weapons grade U233.

As for the various liquid salt reactors, it all depends on whether or not and how effectively Pa is removed. The Pa + neutron reaction hurts the breeding ration by consuming both Pa and neutrons. To maximize the breeding ratio it would be desirable to separate out the Pa and put it somewhere away from neutrons where it can decay to U233. If you had a process for this that was incredibly efficient than you could make weapons grade U233.

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

#53

Post by toomuchtodo »

lighthawk wrote: post #40
bradleyjg wrote: post #30

The biggest problem with nuclear is making the numbers work. You end up paying something like 80% of the cost 1 GW/year * 50 years before you get your first cent in revenue. That's a very tough thing to finance. Cost and especially time overruns during construction can easily tank the project financially. About the only way to make it work is to be a regulated utility that has a long term captured audience for its po…

So you're saying that no nuclear plants are going to be built because of the threat of renewable energy sources becoming cheaper or perhaps other tech like fusion?: http://www.geek.com/science/germany-is-ready-to-switch-on-it...

Are you comparing an experimental technology like Germany's fusion reactor to proven wind generation that is driving commercial reactors out of business?

http://midwestenergynews.com/2015/05/01/exelon-we-have-to-ha...

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

#54

Post by merpnderp »

ebbv wrote: post #17

This article is pretty terrible. The bias is just ridiculous. When discussing wind and solar the author constantly makes assumptions that favor worst cases, and makes questionable comparisons. For example; stating that "more Americans" died from installing rooftop solar than have died from construction or use of nuclear power, cherry picking the most dangerous possible activity related to solar power (some guy up on…

I think ""more Americans" died from installing rooftop solar than have died from construction or use of nuclear power" includes all aspects of nuclear power. The "or use" would seemingly include operating nuclear plants. And given the incredibly low number of deaths in the US associated with nuclear power production, it seems fair.

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

#55

Post by toomuchtodo »

martinald wrote: post #48
bradleyjg wrote: post #30

The biggest problem with nuclear is making the numbers work. You end up paying something like 80% of the cost 1 GW/year * 50 years before you get your first cent in revenue. That's a very tough thing to finance. Cost and especially time overruns during construction can easily tank the project financially. About the only way to make it work is to be a regulated utility that has a long term captured audience for its po…

That doesn't make any sense. Wind and Solar PV have to be financed for probably 99% of the upfront cost. All power generation is like that - very capital intensive.

Wind and solar can be built MW project by MW project, and turned up in weeks or months. You'll take years just to get a nuclear reactor approved.

EDIT: What's that Bezos quote? "Your margin is my opportunity?" Same for renewables. Your delays are my opportunity.

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

#56

Post by sjwright »

tomcam wrote: post #21

I am not reflexively anti-nuclear. However, I have never heard a satisfactory answer to the simple question: "How do we store nuclear waste safely?"

You don't just store it, you repeatedly reprocess and reuse it to extract all of the valuable highly energetic material. The remainder can be stored in geologically stable underground facilities, where it is no more environmentally impactful than uranium ore was prior to being mined.

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

#57

Post by onli »

martinald wrote: post #48
bradleyjg wrote: post #30

The biggest problem with nuclear is making the numbers work. You end up paying something like 80% of the cost 1 GW/year * 50 years before you get your first cent in revenue. That's a very tough thing to finance. Cost and especially time overruns during construction can easily tank the project financially. About the only way to make it work is to be a regulated utility that has a long term captured audience for its po…

That doesn't make any sense. Wind and Solar PV have to be financed for probably 99% of the upfront cost. All power generation is like that - very capital intensive.

Of course that does make sense. To build a wind mill and to distribute the costs is a totally different kind of economic endeavor than to build and finance a nuclear power plant, which can only be profitable with state subventions anyway.

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

#58

Post by x3n0ph3n3 »

tomcam wrote: post #21

I am not reflexively anti-nuclear. However, I have never heard a satisfactory answer to the simple question: "How do we store nuclear waste safely?"

Thorium waste has a half-life at ~100 years. We can certainly build containers to safely store that waste until it is no longer harmful.

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

#59

Post by Retric »

merpnderp wrote: post #36
toomuchtodo wrote: post #28

Earlier quoted context omitted.

Everyone brushes over that, the billions of dollars to build a plant, and the ~10 year construction time. Any nuclear power plant that has construction started today won't be cost competitive with renewables when it comes online. It would be like building a new coal plant in the US today. You simply can't compete with wind, solar, and natural gas (which is still superior to coal, and I don't mind it being a stranded…

How do wind and solar provide a solid baseline power. And China builds nuclear plants a lot faster and cheaper than we do, and no known accidents. Maybe we can learn something from them. Plus the whole 90% of a nuclear plant's cost is servicing the debt. Once completed the operational costs are a rounding error.

Over capacity and in the US Hydro can easily cover most issues. Other areas may use peaking power plants or grid storage just like today.

PS: If you build more wind than you need it does get slightly more expensive, but the wasted peaks are a fairly low percentage of energy generation so there not that important. ie. If you build 5% more wind than you need the cost only increases by 5% but you need to time shift far less power. Considering how much cheaper wind is than Nuclear you can have a lot of extra capacity factor.

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

#60

Post by Alupis »

vanessapu wrote: post #44
Alupis wrote: post #34

Earlier quoted context omitted.

They aren't nearly as dangerous as the popular opinion would have you believe. There has been only a single incident that I'm aware of (Chernobyl), all others were near incidents (Three Mile Island, Japan, etc...). In fact, the technology and safety has come a long way since the 60's. Most US Navy ships are nuclear powered, and have not had incidents (and these are designed to go to war and survive). Japan was hit by…

> They aren't nearly as dangerous as the popular opinion would have you believe. Great! I'm glad that you are volunteering your backyard as the storage facility :)

> Great! I'm glad that you are volunteering your backyard as the storage facility :)

(I see you're new to HN, so your sarcasm can be excused. Just note it won't get you great responses from most HN'ers...)

You might be surprised... most major cities have a nuclear plant nearby (in the US they are mostly shut down at the moment, but are in ready state to re-activate if needed).

I live near one -- even when it was active. I've swam and canoed in the cooling water reservoir (a man-made lake), and I'm not glowing green...

They don't explode or anything... the worst case scenario would be a Chernobyl-like incident where a radius would have to be evacuated... however that scenario is very unlikely to play out in modern times (Chernobyl occurred mostly because the Soviet government was far more interested in containing the story rather than containing the meltdown, leading to a series of wrong choices being made).

Post reply on HN