[HN Gopher] The Nuclear Lightbulb (2020)
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The Nuclear Lightbulb (2020)
Author : othello
Score : 53 points
Date : 2021-04-11 17:28 UTC (5 hours ago)
(HTM) web link (beyondnerva.com)
(TXT) w3m dump (beyondnerva.com)
| tyingq wrote:
| _" For those of us of a certain age, there was a toy that was
| quite popular: the Easy-Bake Oven...Rather than having a more
| normal resistive heating element as you find in a normal oven,
| though, a special light bulb was mounted in the oven, and the
| waste heat from the bulb would heat the oven enough to cook the
| food."_
|
| I can't find any evidence that the Easy Bake oven used a
| "special" light bulb. It just used 2 normal 100 watt incandescent
| bulbs as far as I can tell. Tungsten is a normal resistive
| heating element, pretty common in electric furnaces.
|
| https://upload.wikimedia.org/wikipedia/commons/1/1e/Premier_...
|
| Though there was a 2006 redesign that apparently didn't go well:
| https://www.cpsc.gov/Recalls/2007/new-easy-bake-oven-recall-...
| Baeocystin wrote:
| The one I played with as a kid used oven light bulbs. They look
| pretty much the same, but solderless construction, and IIRC
| quartz glass and a slightly more robust filament.
| tyingq wrote:
| Hmm. Any idea roughly what year? The manuals I can find
| online all say "standard light bulb".
|
| Like:
|
| https://imgur.com/a/uF9ffe1
|
| https://imgur.com/a/F7WwpGg
| Baeocystin wrote:
| Huh. Interesting. This would have been the late 70's/early
| 80's.
| Black101 wrote:
| I just want a nuclear car...
| SigmundA wrote:
| A Tesla with nuclear power plants...
| Black101 wrote:
| but you have to stop to charge... I guess wireless charging
| is coming though
| nosmokewhereiam wrote:
| "Our water pump went out" would go from being a 2 hour side of
| the road fix or tow to potentially a mutli-decade incident...
|
| Either add a second pump or just power it from a legit non-
| mobile federally rated reactor plant.
| klyrs wrote:
| Sure, but imagine it -- the road would be traffic-free for
| decades! Nevermind the trees growing in the street...
| Scoundreller wrote:
| "If we stop, we'll overheat. We must go faster".
| coolandsmartrr wrote:
| In case you can't see the original link:
| https://web.archive.org/web/20210130190443/https://beyondner...
| philipkglass wrote:
| I read some of the old United Aircraft Corporation reports about
| the nuclear light bulb reactor the other weekend. The design
| parameters are delightfully extreme. You can see why it wasn't
| tested in later years. By the 1970s there was already much
| diminished tolerance for experiments that ejected fission
| products into the environment, and effective release prevention
| for testing this design would be expensive.
|
| Here's one of the reports, from 1969:
| https://core.ac.uk/download/pdf/85241637.pdf
|
| Some highlights from this report:
|
| - The fully gaseous core would operate at a pressure of 200
| atmospheres. This is somewhat higher than the pressure in a
| pressurized water reactor core.
|
| - The vapor/plasma fuel temperature would be 42000 Rankine.
| That's about 23300 Kelvin, roughly 4 times as hot as the surface
| of the Sun.
|
| - The fiberglass pressure vessel was projected to last about 6000
| seconds (100 minutes) of full power operation before its strength
| was compromised by neutron irradiation.
|
| - The preferred fuel was uranium 233, which does not exist to any
| considerable degree in nature. It has to be bred from thorium.
| Since U-233 never had significant use in civil or military
| nuclear applications, the US has not produced any U-233 since the
| 1980s [1]. Highly enriched uranium 235 or plutonium 239 would
| also work, just not as well. All fueling options needed "bomb
| grade" fuel purity. That was the only way to make the reaction
| zone so compact.
|
| Other details that I recall from other reports -- sadly not ready
| to hand:
|
| - Later iterations of the design kept thinning the quartz
| envelope to maintain adequate transparency to UV radiation after
| accounting for color centers induced by radiation damage. This
| required aggressive/optimistic estimates of how perfectly
| pressure could be equalized on both sides of the envelope,
| particularly during start-up.
|
| - The optimal core fuel temperature would have been _even higher_
| except that it was difficult to find materials that would be
| adequately transparent to even shorter ultraviolet radiation.
|
| - Fission products were supposed to be separated from the fuel
| centrifugally before the fuel recirculated into the reaction
| zone. This seems chemically optimistic to me.
|
| - There was little consideration of chemical factors in any of
| the reports I read. Given that the environment was extremely hot,
| rich in fluorine, and would soon contain most elements of the
| periodic table from fission products, this seems like an
| oversight. One that would probably be testable only by actually
| building and operating test reactors.
|
| [1] https://www.world-nuclear.org/information-library/current-
| an...
| Causality1 wrote:
| Things like this make me wonder how cheap a truly commoditized
| nuclear industry could be. What kind of lifestyle are we giving
| up by requiring orders of magnitude fewer deaths-per-megawatt-
| hour of nuclear compared to fossil fuels? What if we were
| civilized enough you didn't have to worry about anyone building
| their own atom bomb?
| numpad0 wrote:
| I think we need to be a spacefaring species to be able to fully
| utilize nuclear energy, and to be a spacefaring species, highly
| automated orbital manufacturing has to be established. Doing
| nuclear on the planet Earth at all is perhaps too akin to doing
| it in the middle of Manhattan island.
| vangelis wrote:
| I think it be a lot like airliners vs small aircraft in terms
| of safety.
| ryan93 wrote:
| Much cheaper than solar and wind.
| URSpider94 wrote:
| There is a lot of very complex, and very real human psychology
| and sociology at play in those decisions. A lot of it centers
| around who accrues the benefits of a given energy source, vs.
| who pays the consequences.
| choeger wrote:
| Not that much. Nuclear energy alone wouldn't really make a huge
| difference. Even if we ignore the obvious problems with safety
| (big issue with older designs and their spent fuel storage) and
| security (huge issue with modern designs) when nuclear power
| would be similarly widespread as, e.g., natural gas: There is
| still the fact that it is inherently a stationary power source
| (with not that many good places to put it). Distribution of
| electricity isn't a big problem, but it doesn't help for
| mobility applications, so we would need the battery or H2
| industry anyways.
|
| Factor in the wastly different levels of difficulty between
| solar and nuclear power, I'd think we would also have the
| latter, if just as a simple alternative when you don't have the
| time or the capital to setup a nuclear power plant. Wind energy
| might be a different matter, as it comes with a lot more
| practical difficulties.
|
| One could simply compare France and Germany to understand how
| things would end up, I think.
| marcinzm wrote:
| >What if we were civilized enough you didn't have to worry
| about anyone building their own atom bomb?
|
| Then we'd be something other than human. You'd need a species
| that values all members equally and has no preference for those
| in the same social group (or family, etc.). Likely it also
| means members cannot value themselves above other members.
| Without all that "civilized" simply means that some group gets
| oppressed and isn't allowed to fight back in any way.
| baybal2 wrote:
| Keeping all core gasses confined is one option. A spec of dust on
| the quart, crytaline defect, hydrogen embrittlement, or anything
| else and you get R.U.D.
|
| Another is not to fight it, and let them go. The closest thing to
| a torch drive possible with modern day engineering after the NSWR
| is the open cycle gas core rocket.
|
| Thrust in meganewtons, and 1000+ ISP
| th8700 wrote:
| Nobody would accept the fallout if it's a ground launch. And if
| it's a space launch, why not go directly to Project Orion?
| baybal2 wrote:
| Given economic considerations, both the open cycle gas core,
| and NSWR may beat practical Orion drives.
| jdc wrote:
| It could make an _excellent_ fourth stage, however.
| JulianMorrison wrote:
| Nobody would accept the fallout if it was a space launch
| either, given that crud might either hang about in LEO
| poisoning it for everyone else, fall out onto the planet
| below, or drift around in space forming a radiation hazard
| for future travel. You'd have to get its speed up to solar
| escape velocity to ensure it wouldn't be captured
| _somewhere_.
| api wrote:
| Use it for the later stages in a many stage interstellar
| rocket. First stages are chemical, then NERVA style
| contained nuclear rockets, then open cycle nuclear when you
| are already well past solar system escape velocity.
|
| I'm thinking of something like an interstellar flyby probe
| for the Centauri system. It wouldn't be able to stop or do
| much course correction but you could send basically an
| autonomous space telescope that transmitted back
| observations. It would be able to see planets in the system
| much better than we can from here.
| mrfusion wrote:
| > drift around in space forming a radiation hazard for
| future travel.
|
| Do you realize how big space is?
| [deleted]
| baybal2 wrote:
| Radiation hazard of single digit nuclear rocket launches
| will completely pale in comparison to total amount of
| radiation coming from Sun, and space.
|
| Do you understand how much radiation it is in space? All
| human nuclear experiments in 20th century together wouldn't
| be even a rounding error there.
| retrac wrote:
| This does not follow. Photons from the sun are not
| radioactive isotopes that can rain down on us as they
| decay from orbit. And the magnetosphere protects us from
| the bulk of the solar wind's traces of heavier isotopes.
| How much plutonium or whatever, is in near-Earth space,
| other than what we've sent up there?
|
| A more pragmatic argument is that, after the uncontrolled
| fission of literal tonnes of plutonium and the release of
| that and the byproducts into the atmosphere in the
| previous century, the small risk of losing a few kg more
| here or there barely registers.
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