Nobody builds nuclear reactors for fun anymore • Hacker News Board

Re: Nobody builds nuclear reactors for fun anymore

#101

Post by ChuckMcM » Sun, Dec 08, 2013, 5:35 PM UTC

wycx wrote: post #87

downer91 wrote: post #61

Earlier quoted context omitted.

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 eas…

That is pretty cool stuff.

Re: Nobody builds nuclear reactors for fun anymore

#102

Post by downer91 » Sun, Dec 08, 2013, 6:10 PM UTC

purringmeow wrote: post #83

downer91 wrote: post #61

Earlier quoted context omitted.

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.

Good point! Water table contamination is yet another hazard.

Fukushima is situated on the coast line, and already leaks into the ocean, but Chernobyl is near the Pripyat river, and is a tributary to the Dnieper River, which empties into the Black Sea. The Pripyat is contaminated within the exclusion zone, but it would be bad news to disturb and agitate any contamination, and make things worse.

Given that it's already a bad situation, and that natural leeching is already taking place by doing nothing, any engineering project would have to approach the site carefully so that leeching is not accelerated.

Yucca mountain is located in the southwest desert, so that mitigates water seepage, but Yucca mountain isn't a disaster site (yet), so that technical challenge can be tackled before it arises.

Re: Nobody builds nuclear reactors for fun anymore

#103

Post by dredmorbius » Sun, Dec 08, 2013, 11:06 PM UTC

XorNot wrote: post #94

dredmorbius wrote: post #88

Earlier quoted context omitted.

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…

See the way I see it, that's asking the wrong question: who cares what civilization is doing 10,000 years from now, if it's lost sufficient record and technology to comprehend nuclear waste? Even a language change, if accompanied by a technologically advanced civilization, would remember to change it's signs. Whereas, it is much more likely that if we don't use nuclear power, we'll create catastrophes that lead to th…

who cares what civilization is doing 10,000 years from now, if it's lost sufficient record and technology to comprehend nuclear waste?

It's possible to retain a knowledge of what nuclear waste is (at least in a mythic sense of "very bad juju") while 1) losing track of where that waste is and 2) being unable to detect or determine where it is.

Humans have no senses which detect radioactivity (one possibility is that such a sense evolves, though I suspect this is unlikely and would take a very long time). Radiation detectors require some level of technology -- silver nitrite films which fog on exposure, cloud chambers, Geiger counters, exposure badges. It's fairly easy to lose track of where radioactive products are; there's already history of radioactive decay products being incorporated into building materials and otherwise going astray (the Mexican truck hijacking this past week is only the most recent of many civilian-use accidents).

So: a future civilization, which does have a written or oral history of nuclear waste and its hazards, but no means of determining what is radioactive, could definitely have some issues going on. What the outcomes of that might be are an interesting question. It's possible there could be a civilization reboot, or humans could make a long-term slide to obscurity and/or extinction.

Re: Nobody builds nuclear reactors for fun anymore

#104

Post by BrandonMarc » Mon, Dec 09, 2013, 1:38 AM UTC

sliverstorm wrote: post #74

_delirium wrote: post #49

Earlier quoted context omitted.

Oh, no disagreement there. I don't think there is in principle a problem with safely storing nuclear waste, in the sense that it would be technically impossible to do it or anything. The problem is that in practice the current solution is to have a bunch of it hanging out in "interim" storage that is not really well planned or designed as permanent storage. That's mostly a political problem, and secondarily an econom…

It's yet another example of the brilliance of the American public when it comes to power. Shut down the nuclear plants! (spin up coal plants instead). Block Yucca Mountain! (pile up spent fuel in short-term storage instead). So on and so forth.

It's yet another example of the brilliance of the American politicians when it comes to power.

Fixed that for you. Coal plants aren't doing so well, either. President Obama has stated many times a major policy goal is to destroy the coal industry - lack of viable alternative not mattering.

Regarding storing spent fuel only in temporary ways, that's just a sad artifact of neither side being able to agree on any long term solution, so no real long term solution gets implemented, and the can gets kicked down the road. It's lunacy not to face reality.

Re: Nobody builds nuclear reactors for fun anymore

#105

Post by BrandonMarc » Mon, Dec 09, 2013, 1:54 AM UTC

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…

Comments like this make me wish I could +2

Re: Nobody builds nuclear reactors for fun anymore

#106

Post by ISL » Mon, Dec 09, 2013, 6:18 AM UTC

rwmj wrote: post #93

ISL wrote: post #22

Earlier quoted context omitted.

We do precision tests of gravity and searches for forces weaker than gravity. (Front page is dated, see publications tab for more recent work) http://www.npl.washington.edu/eotwash/ The most-important experiment we do is to test the Equivalence Principle [1], the idea that if you drop two things in vacuum, they'll fall at the same rate regardless of what they're made from. Results from our lab have shown that, at 1 p…

I would really enjoy a blog post/series about what you're doing. I'm sure you think it's ordinary and slightly boring but you'd surprised how many -- even technical -- people have no idea how you can measure gravity over the breadth of a hair, and would be fascinated by it.

I'll definitely think about it. I suspect shipping my thesis will happen first :).

Re: Nobody builds nuclear reactors for fun anymore

#107

Post by NamTaf » Mon, Dec 09, 2013, 6:30 AM UTC

Intermernet wrote: post #67

ISL wrote: post #43

Earlier quoted context omitted.

My apologies for the terse nature of my summary above. We measure the deflection of light bounced from a mirror attached to a test mass hanging from a very fine wire. That said, the geometry of some of the Texas Instruments DLP MEMS chips has interested some of us for years. The chips are designed to be robust in consumer products, but if they instead designed their mirrors to have very soft springs, we'd be interest…

Thanks for the detailed reply. Good to know it wasn't a completely stupid question! Sorry, not US, Australian. Although I just checked and QUT in Brisbane are apparently doing some good work in microgravity research. Time to do some reading!

Interesting. Dr Steinberg actually did his design thesis at UQ and there's a 1999 article saying it'd be built there, but by the looks of it he then jumped over to QUT and built it there instead. I certainly don't remember it existing at UQ when I was there in ~2005.