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Nobody builds nuclear reactors for fun anymore

blogs.scientificamerican.com

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Re: Nobody builds nuclear reactors for fun anymore

#31

Post by zxcdw »

coldtea wrote: post #28
ChuckMcM wrote: post #10

My daughter was one of the operators of the TRIGA reactor at Reed college. Some of the students joked it was a Fisher-Price My First Reactor reactor :-) at only 250kW its small as reactors go, but also exceptionally interesting. It is very disappointing how constricted the field of nuclear research is, as it is a demonstrably zero carbon footprint energy source. I understand the emotion that nuclear power evokes in p…

> It is very disappointing how constricted the field of nuclear research is, as it is a demonstrably zero carbon footprint energy source. Yes, if only it didn't have any other footprint...

Is this a real world problem with real world consequences?

It is my understanding that the nuclear waste can be stored safely without too much cost. It is also my understanding that there are ways to re-use the already used fuel rods, effectively 1) making them radiate less 2) getting "leftover" power from already consumed fuel.

Psychological footprint fueled by ignorance however... Well, that borders religiousness. Maybe education and awareness helps.

Re: Nobody builds nuclear reactors for fun anymore

#32

Post by DennisP »

This is one reason I've started to think fusion might be more promising than advanced fission. The regulatory barriers are so light that high school students build reactors and run them on deuterium fuel just like most of the big projects, and it's perfectly legal.

There's quite a lot of work being done on small-scale alternative reactor designs. I wrote up a bunch of them here: http://www.climatecolab.org/web/guest/plans/-/plans/contestI...

Re: Nobody builds nuclear reactors for fun anymore

#33

Post by gngeal »

ISL wrote: post #29
sillysaurus2 wrote: post #21

Earlier quoted context omitted.

Experimental gravity? I went into the wrong field. What's experimental gravity?

See my reply to s800. Before you jump ship to precision tests of gravity: graduate students' mean time to graduation in our group is >7-8 years. Our experiments take several years to set up, at least a year to execute, and at least a year to analyze. When a new idea/theory comes up, we can often test it quickly (or rule it out with existing measurements), but our bread-and-butter work is a direct confrontation with h…

Essentially, you're trying to do what the medical research isn't doing: to invalidate the existing papers. :-)

Re: Nobody builds nuclear reactors for fun anymore

#34

Post by ISL »

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?

It's far from solved, but there are partial solutions, including reprocessing.

My appeal to dabblers was to think through the entire life cycle of an experiment before beginning. If I were to crack open a smoke detector in order to play around with the Americium source, I'd think hard first about whether I actually knew what I was doing, making sure I worked in a clean/orderly environment, that the entire experiment was nicely contained, and that I had a viable plan for how to safely manage the waste I'd created.

Just as with the bathtub ring in "The Cat in the Hat Comes Back" [1], once contamination leaves containment, it can wander everywhere, generating lots of low-level waste. You'd rather not eat or aspirate an alpha-emitter.

Nobody wants an unsafe nuclear experiment in the garage next door; it's irresponsible. It's one thing to hurt yourself, but quite another to harm someone unaware of a risk. It's also irresponsible to dispose of a hot source in your garbage can. That source may no longer be able to hurt you, but it's able to harm everyone who comes into contact with it in the future.

Our lab's standard for whether or not something has been cleaned up: any residual activity is comparable to/indistinguishable from background, and any activated waste has been disposed of with someone licensed to handle it.

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

Re: Nobody builds nuclear reactors for fun anymore

#35

Post by ISL »

gngeal wrote: post #33
ISL wrote: post #29

Earlier quoted context omitted.

See my reply to s800. Before you jump ship to precision tests of gravity: graduate students' mean time to graduation in our group is >7-8 years. Our experiments take several years to set up, at least a year to execute, and at least a year to analyze. When a new idea/theory comes up, we can often test it quickly (or rule it out with existing measurements), but our bread-and-butter work is a direct confrontation with h…

Essentially, you're trying to do what the medical research isn't doing: to invalidate the existing papers. :-)

We're trying to figure out what's true.

Perhaps the most important function of precision experimental tests (all of them, not just ours), is to provide very tight constraints for new theories. Any successful new theory of physics must ultimately explain more observed phenomena than existing theory. If experiment is more sensitive than existing theories, it can provide a quick checksum for whether a new theory is correct.

Furthermore, if a precision measurement is able to show that existing theory is not quite correct, it can lead the way to better theories.

In the field of precision gravity, Newton's and Einstein's theories have been perhaps frustratingly correct. At present, nobody knows if/how the "Standard Model" and gravity might connect. They're mathematically incompatible.

With respect to any existing literature, most physicists' position might be approximately summarized as, "Trust, but verify."

Re: Nobody builds nuclear reactors for fun anymore

#36

Post by jrockway »

ISL wrote: post #22
s800 wrote: post #20

Earlier quoted context omitted.

What is Experimental Gravity? serious. tnx.

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…

This is much more interesting than the original article. Thanks for posting.

Re: Nobody builds nuclear reactors for fun anymore

#37

Post by Intermernet »

ISL wrote: post #22
s800 wrote: post #20

Earlier quoted context omitted.

What is Experimental Gravity? serious. tnx.

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…

Pardon my complete lack of knowledge in this field, but would MEMS (or NEMS) mirror arrays be sensitive / accurate enough to measure the gravitational effect on light at the scales you're talking about?

I'm surprised to read the statement "over distances smaller than the diameter of a hair, nobody knows if gravity acts" as I thought we were accurately measuring all sorts of interactions at or below that scale (10s of microns).

It sounds like a very interesting field to be in!

Re: Nobody builds nuclear reactors for fun anymore

#39

Post by notahacker »

zxcdw wrote: post #31
coldtea wrote: post #28

Earlier quoted context omitted.

> It is very disappointing how constricted the field of nuclear research is, as it is a demonstrably zero carbon footprint energy source. Yes, if only it didn't have any other footprint...

Is this a real world problem with real world consequences? It is my understanding that the nuclear waste can be stored safely without too much cost. It is also my understanding that there are ways to re-use the already used fuel rods, effectively 1) making them radiate less 2) getting "leftover" power from already consumed fuel. Psychological footprint fueled by ignorance however... Well, that borders religiousness.…

This looks like a pretty big real world consequence to me: https://www.google.co.uk/search?q=chernobyl&safe=off&espv=21...

Say what you like about the strength of the evidence linking burning of hydrocarbons and climate change, but it doesn't carry the risk of a meltdown leaving a footprint so big and dangerous that cities have to be abandoned. I don't think it's "ignorance... that borders religiousness" that keeps the field of nuclear research heavily constrained and very expensive.

Re: Nobody builds nuclear reactors for fun anymore

#40

Post by snom380 »

zxcdw wrote: post #31
coldtea wrote: post #28

Earlier quoted context omitted.

> It is very disappointing how constricted the field of nuclear research is, as it is a demonstrably zero carbon footprint energy source. Yes, if only it didn't have any other footprint...

Is this a real world problem with real world consequences? It is my understanding that the nuclear waste can be stored safely without too much cost. It is also my understanding that there are ways to re-use the already used fuel rods, effectively 1) making them radiate less 2) getting "leftover" power from already consumed fuel. Psychological footprint fueled by ignorance however... Well, that borders religiousness.…

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).
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