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

Nobody builds nuclear reactors for fun anymore

blogs.scientificamerican.com

Post reply on HN
Print view View original

81–90 of 107 posts

Re: Nobody builds nuclear reactors for fun anymore

#81

Post by dredmorbius »

ChuckMcM wrote: post #72
dredmorbius wrote: post #45

Earlier quoted context omitted.

The fact that a reactor is fueled by waste doesn't mean it doesn't create waste or have a waste-disposal aspect. In the case of any nuclear reactor, the vessel and mechanism itself becomes radioactive and must be disposed of (the same process also leads to embrittlement and other issues with the vessel/structure itself). And the resulting fission products are also still radioactive and require disposal, though my und…

This is an important point, so let's be precise here. The fact that a reactor is fueled by waste doesn't mean it doesn't create waste or have a waste-disposal aspect. There is nothing in the physics of building nuclear reactors that prevents us from building a reactor that does not leave behind any waste that is either chemically reactive, or even modestly radioactive. No currently implemented reactor designs do that…

There is nothing in the physics of building nuclear reactors that prevents us from building a reactor that does not leave behind any waste

First I've every heard of any such proposal. How exactly would you go about stabilizing every last decay product to the level of background radiation?

Your statement is equivalent to noting that there's nothing in chemistry which prevents us from building coal-fired power plants which capture all CO2 and toxic pollutants (mercury, sulfur, particulates, NOX,, radioactives, etc.) as well. However it's economically and thermodynamically infeasible. Not that emissions haven't been drastically reduced from early designs, but it turns out that that's still not good enough.

Re: Nobody builds nuclear reactors for fun anymore

#82

Post by moca »

pflanze wrote: post #30
ISL wrote: post #8

To make an an HN-relevant analogy: The FDA-hobbling of 23andMe pales in comparison to what it's like to work with nuclear regulatory frameworks and societal concerns regarding nuclear science. When I was an undergrad, DOE was willing to pay the university the entire relicensing and operating costs of the on-campus TRIGA. The university declined, knowing that the requisite environmental impact study for relicensing wo…

I'm not sure what you mean with litter, but isn't nuclear waste storage still an unsolved problem?

If we want sustainable nuclear energy, the only solution would be fast reactor that can burn nuclear waste. Politically, it is near impossible to find a place to build nuclear waste storage. Nobody know how safe is such a storage. If we can burn nuclear waste, we will have sufficient clean energy for several hundred years. By then, nuclear fusion will be harnessed, and we will have enough energy for next many million years, and they have much less environmental impact.

Re: Nobody builds nuclear reactors for fun anymore

#83

Post by purringmeow »

downer91 wrote: post #61
coldtea wrote: post #51

Earlier quoted context omitted.

> Is this a real world problem with real world consequences? Might not be where you live, but there's a real world evacuated zone in Chernobyl, with a 20 mile radius were "even today radiation levels are so high that the workers responsible for rebuilding the sarcophagus are only allowed to work five hours a day for one month before taking 15 days of rest. Ukrainian officials estimate the area will not be safe for hu…

But let's get creative about the realities of hazardous radioactive waste storage. It's not an impossible problem to solve, when you think about it pragmatically. It's difficult, expensive, requires material resources, expertise and dedication, but it's not impossible. The typical and most reliable procedure for managing radioactive waste is vitrification: creating a purified mixture of molten glass and then introduc…

You can't dig below the reactor, because there is a high chance of the whole structure collapsing and getting in contact with water.

However, I share your opinion on dealing with radioactive waste. It's not a technical challenge, but a political one.

Re: Nobody builds nuclear reactors for fun anymore

#84

Post by snom380 »

Daniel_Newby wrote: post #56
snom380 wrote: post #40

Earlier quoted context omitted.

I think the biggest problem is to guarantee that some future civilization will not dig up the waste believing it to be valuable, like we did with the old Egyptian graves. We could make it very difficult to do so, but it's not a "solved problem". http://vimeo.com/55736976 is an interesting watch (although perhaps a bit biased).

It's a solved problem. Dilute it with sand until it is about as radioactive as the original ore, melt the sand, and dump the chunks of glass someplace out of the way. Yes, future generations will need to protect themselves from it, but they already need to in huge areas where the ground emits radon.

If that's truly cost effective and feasible, why isn't it being done on a wider scale?

Re: Nobody builds nuclear reactors for fun anymore

#85

Post by XorNot »

dredmorbius wrote: post #80
XorNot wrote: post #64

Earlier quoted context omitted.

As opposed to coal, oil and gas fracking? I sure rest assured that when the local groundwater and aquifiers for my city are too toxic to drink, well at least I'll only be dying of organic and heavy metal poisoning.

As opposed to coal, oil and gas fracking? Tu quoque fallacy. No, I didn't say that these weren't. If you want to know, rather than project on me, my beliefs, you could ask me. As it happens, my view is that humans, as with other life forms, exist to perform the function of exploiting low-entropy energy stocks and flows. The consequences of that ... tend not to be something we consider in advance. We've benefited huge…

Sorry that was probably more hostile then necessary, but when it comes to nuclear power there is very much a "but what about the waste aspect!" used in a manner which implies all other fuel sources don't have very serious problems as well.

Re: Nobody builds nuclear reactors for fun anymore

#86

Post by dmfdmf »

Barring some exciting breakthrough in physics that gives us either a new energy source or high-efficiency solar and the ability to store it, eventually nuclear will come back. It is the only viable civilization-scale power source that can keep the heat, lights and computers on once the oil runs out.

Re: Nobody builds nuclear reactors for fun anymore

#87

Post by wycx »

downer91 wrote: post #61
coldtea wrote: post #51

Earlier quoted context omitted.

> Is this a real world problem with real world consequences? Might not be where you live, but there's a real world evacuated zone in Chernobyl, with a 20 mile radius were "even today radiation levels are so high that the workers responsible for rebuilding the sarcophagus are only allowed to work five hours a day for one month before taking 15 days of rest. Ukrainian officials estimate the area will not be safe for hu…

But let's get creative about the realities of hazardous radioactive waste storage. It's not an impossible problem to solve, when you think about it pragmatically. It's difficult, expensive, requires material resources, expertise and dedication, but it's not impossible. The typical and most reliable procedure for managing radioactive waste is vitrification: creating a purified mixture of molten glass and then introduc…

There are superior solutions to vitrification. Synroc [1] is technically far superior as it puts the long lived isotopes into mineral phases in which they are stable, as opposed to metastable glass.

Once stablised as synroc it is simply a matter of storing the waste. Storing above ground (i.e. in a shed) seems to me to be a better solution than pursuing geologic disposal, given the waste is now stable, and can be easily monitored.

[1] http://en.wikipedia.org/wiki/Synroc

Re: Nobody builds nuclear reactors for fun anymore

#88

Post by dredmorbius »

XorNot wrote: post #85
dredmorbius wrote: post #80

Earlier quoted context omitted.

As opposed to coal, oil and gas fracking? Tu quoque fallacy. No, I didn't say that these weren't. If you want to know, rather than project on me, my beliefs, you could ask me. As it happens, my view is that humans, as with other life forms, exist to perform the function of exploiting low-entropy energy stocks and flows. The consequences of that ... tend not to be something we consider in advance. We've benefited huge…

Sorry that was probably more hostile then necessary, but when it comes to nuclear power there is very much a "but what about the waste aspect!" used in a manner which implies all other fuel sources don't have very serious problems as well.

The law of unintended consequences has a damned long arm, that's for sure.

Perturbing systems creates long-lived ripple effects. Humans have been tapping into stored carbon equivalent to a few hundred million years of fossil deposits, and ... that's going to have some really long-lived effects. As to what the future holds, my sense is that we're simply not going to have the quantities of free, abundant, and fungible energy we've enjoyed for the past century or so. There are a few people who've arrived at similar conclusions (Dennis Meadows, one of the original Limits to Growth team is among them).

The problem with nuclear waste for me (and others -- Hyman Rickover's criticisms of nuclear energy are revealing) is that the stuff is of such a concern for such a long period of time -- literally longer than written history. How the hell do you create a warning iconography that's going to be comprehensible in 10,000 years, or even 2000? Spoken and written English of even 700 years ago (Geoffrey Chaucer) is barely comprehensible today. And structures to contain it? The very oldest intact buildings we know of are massive stone monuments and even they are both heavily weathered and have long since been plundered (pyramids and other archaeological sites).

The primary problem with oil and coal are simply the quantities we've been consuming of them. If human populations hadn't grown, and they simply substituted for the biomass which was being consumed in their stead prior to the Industrial Revolution, they'd be far less consequential.

I should try figuring out how large a population could be supported at, say, 50% of US rates of energy consumption...

Re: Nobody builds nuclear reactors for fun anymore

#89

Post by joe_the_user »

zxcdw wrote: post #48
_delirium wrote: post #42

Earlier quoted context omitted.

It can be stored safely, but so far a good waste solution hasn't been implemented, at least in the US. With the cancellation of Yucca Mountain, the current "interim" long-term storage plan is basically on-site dry cask storage scattered everywhere. The spent-fuel pools are an even bigger mess. Many of them are filling up, and fuel isn't being transferred from them to longer-term storage even when it could/should be,…

A non-US citizen here, so I have practically no understanding of the politics related to US nuclear power. However, the Wikipedia article for Yucca Mountain nuclear waste repository seems to mention that the cancellation was for political rather than for technical reasons. Wouldn't this imply, that the opposing forces aren't technological, but rather political? As in, if there's will, the problem can be at least part…

Coal, oil and gas kill quite a number of people today, invisibly and at-semi-random. Say X people die.

If you had a power source that killed X/100 people. But to implement that power source, congress would have to introduce a bill in which every single person who had to die was named.

Could that power source be implemented in any democracy?

(not to say nuclear is exactly like this, just to say nuclear has a bit of this kind of problem and this kind of problem is very hard to solve)

Re: Nobody builds nuclear reactors for fun anymore

#90

Post by russellsprouts »

adamnemecek wrote: post #38

There were a couple of IAMA's on reddit with some teenagers who (supposedly) build nuclear reactors http://www.reddit.com/r/IAmA/comments/hmn56/iama_teenager_wh... http://www.reddit.com/r/IAmA/comments/xd19t/iama_an_incoming...

These are impressive, but they aren't fission reactors, but fusion reactors. They do not generate power, but they do convert hydrogen to helium.
Post reply on HN