NASA completes full-power tests of small, portable nuclear reactor • Hacker News Board

Re: NASA completes full-power tests of small, portable nuclear reactor

#121

Post by Latteland » Sat, May 05, 2018, 3:17 AM UTC

credit_guy wrote: post #6

netzone wrote: post #4

What would the effects be of releasing nuclear waste in space? Could we sent up all of our nuclear waste, put a rocket on it and just let it disappear into the distance?

You would need a huge fleet of huge rockets to do that. Of the order of 50 Saturn V - sized rockets per year just to keep up with the current production of nuclear waste. And about 1000 of them to get rid of what we accumulated so far. Only 13 Saturn V’s have ever been launched.

The cheapest choice would be the falcon block 5. Gooooo spacex.

Re: NASA completes full-power tests of small, portable nuclear reactor

#122

Post by MertsA » Sat, May 05, 2018, 2:58 PM UTC

IdeaHamstir wrote: post #111

philipkglass wrote: post #109

Earlier quoted context omitted.

Here's a photo series from 2005 at a Swedish nuclear fuel facility showing how uranium turns into fuel pellets and fuel rod bundles: https://www.iaea.org/newscenter/multimedia/photoessays/train... At all stages the material can be handled with no more protection than gloves. It is roughly as dangerous as handling lead fishing weights until the fuel actually attains criticality.

It still produces a fair bit of alpha, so avoid particulate ingestion.

I don't know why people downvoted this, it's entirely correct. Although I guess the larger concern than the radiation would be the heavy metal poisoning but in any case it's still fine, just treat it like you would any other heavy metal.

Re: NASA completes full-power tests of small, portable nuclear reactor

#123

Post by ttul » Sat, May 05, 2018, 4:36 PM UTC

baybal2 wrote: post #58

ttul wrote: post #25

Earlier quoted context omitted.

Hmm. Why not talk to Etalim: https://www.etalim.com/ They invented and are very close to commercializing a direct heat-to-electricity converter that uses acoustic waves. No moving parts. Close to 30% efficiency.

It is effectively another stirling, just with membrane instead of piston, and very high frequency of operation. Sound == heat. An AMTEC converter may be an another "fully self-contained" solution

No moving parts is the key advantage.

Re: NASA completes full-power tests of small, portable nuclear reactor

#124

Post by perl4ever » Sun, May 06, 2018, 1:36 AM UTC

petra wrote: post #61

philipkglass wrote: post #45

Some background on this: NASA deep space missions have historically used radioisotope thermal generators powered by the decay of the exotic plutonium isotope Pu-238. This isotope has a good balance of lifetime (87.7 year half life) and specific energy (0.5 watts/gram). It is non-fissile -- no risk of criticality. It also decays solely by alpha emission, so there are no problems with shielding the rest of the systems…

The major fear that comes up with these is: what if the missile blows up while still in earth? How are these risks managed?

The Soviets launched over 30 satellites with nuclear reactors in the past. The US also launched one. Most of them are still in orbit and I only know of one that scattered nuclear waste all over Canada.

See https://en.wikipedia.org/wiki/Kosmos_954 and https://en.wikipedia.org/wiki/US-A

Re: NASA completes full-power tests of small, portable nuclear reactor

#125

Post by dukoid » Tue, May 08, 2018, 10:16 AM UTC

rsynnott wrote: post #21

dukoid wrote: post #9

Earlier quoted context omitted.

How about just sending it to the moon instead? Perhaps then we could use the moon as a giant space ship by blowing up the nuclear waste?

Alexander Abian, is that you? ( https://en.wikipedia.org/wiki/Alexander_Abian )

Maybe he has watched too much "Space 1999"? https://en.wikipedia.org/wiki/Space:_1999