8 ms·

The Nuclear Lightbulb (2020)

89 points by othello 5y ago

coolandsmartrr 5y ago
In case you can't see the original link: https://web.archive.org/web/20210130190443/https://beyondnerva.com/2020/03/21/the-nuclear-lightbulb-a-brief-introduction/ https://web.archive.org/web/20210130190443/https://beyondner...
Causality1 5y ago
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?
- vangelis 5y ago
  I think it be a lot like airliners vs small aircraft in terms of safety.
- URSpider94 5y ago
  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.
  - asdff 5y ago
    On the other hand, the consequences have already been paid. There are plenty of highly irradiated places on earth already that could be used for future nuclear projects.
- choeger 5y ago
  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 5y ago
  >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.
- numpad0 5y ago
  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.
- ryan93 5y ago
  Much cheaper than solar and wind.
- 7952 5y ago
  As you are asking open ended questions. What do you think is an appropriate level of deaths per MWh? Can you put a number on it? And how do you engineer a reactor to accurately and repeatedly achieve a certain risk level?
  - Causality1 5y ago
    Well, one answer to that is when the lives saved by nuclear balance out the lives cost by fossil fuels. Nuclear currently has a rate of 0.07 deaths per terawatt-hour. Coal has a rate of 24.6 deaths per terawatt-hour. If fully replacing coal with nuclear required making nuclear a hundred times more dangerous than it is now it would still be completely justified. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(07)61253-7/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
    - 7952 5y ago
      So imagine a nuclear plant that saves costs by reducing safety margins. You have less redundancy in equipment and staff, less containment, or whatever. How do you accurately predict the risk? And what error would that risk have? Every single factor you are modifying can come together in weird combinations and has an error bar of its own. What happens when there is suicidal engineer + metal fatigue + unusual weather conditions? Ultimately this seems like a fools errand. The belt-and-braces approach is the only way humans have found to safely design complex inherently risky machines. And deviating from that creates Shuttle shaped clouds in the sky and Boeing shaped holes in the ground.
tyingq 5y ago
"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_model_Easy_Bake_oven.jpg 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-following-partial-finger-amputation-consumers-urged-to-return https://www.cpsc.gov/Recalls/2007/new-easy-bake-oven-recall-...
- Baeocystin 5y ago
  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 5y ago
    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/uF9ffe1 https://imgur.com/a/F7WwpGg https://imgur.com/a/F7WwpGg
    - Baeocystin 5y ago
      Huh. Interesting. This would have been the late 70's/early 80's.
- markc 5y ago
  >Easy-Bake Oven You can buy a Panasonic FlashXpress toaster oven and get the Easy-Bake experience. Great toaster! Fast and very predictable. It starts cooking immediately and every toast cycle is the same duration. In a regular toaster oven it takes a while for the heating element to get hot before it starts to actually toast the bread. If you immediately cook a second batch of toast for the same amount of time it burns.
baybal2 5y ago
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 5y ago
  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 5y ago
    Given economic considerations, both the open cycle gas core, and NSWR may beat practical Orion drives.
  - jdc 5y ago
    It could make an excellent fourth stage, however.
  - JulianMorrison 5y ago
    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 5y ago
      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.
philipkglass 5y ago
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 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-and-future-generation/thorium.aspx https://www.world-nuclear.org/information-library/current-an...
- 5y ago
Black101 5y ago
I just want a nuclear car...
- Scoundreller 5y ago
  “If we stop, we’ll overheat. We must go faster”.
- nosmokewhereiam 5y ago
  "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 5y ago
    Sure, but imagine it -- the road would be traffic-free for decades! Nevermind the trees growing in the street...
- SigmundA 5y ago
  A Tesla with nuclear power plants...
  - Black101 5y ago
    but you have to stop to charge... I guess wireless charging is coming though
- dirktheman 5y ago
  Ford actually envisioned nuclear cars in the 1950s: https://en.wikipedia.org/wiki/Ford_Nucleon https://en.wikipedia.org/wiki/Ford_Nucleon
adewinter 5y ago
If anyone would like to work on a startup focused on Nuclear Propulsion, please reach out.
- gloriana 5y ago
  yea for sure - nuke engineer here - is it an established startup or just getting started?
- transistor-man 5y ago
  You got my attention, contact information is in my profile
- hairytrog 5y ago
  there's these guys: https://usnc.com/careers/ https://usnc.com/careers/
- black6 5y ago
  I'm a chemical rocket engine test engineer; I'll bite.
- atdrummond 5y ago
  I’m interested.
- slotkin 5y ago
  interesting to hear what you're working on!
- gpm 5y ago
  Canadian software engineer here, would be interested to hear more but if you're US based ITAR may be a problem. Email is in profile.
pfdietz 5y ago
I think you should be able to achieve an Isp approaching that of this rocket with a solid core nuclear reactor, without radiators, although at much lower T/W ratio. The idea would be to not just dump hydrogen into the reactor to heat it, but gradually warm that hydrogen, extracting as much power as one could along the way. At the end, this power would be used to superheat the hydrogen after it went through the reactor (by some sort of electrical heating), to a temperature greater than the reactor's temperature limit. Alternately, the exhaust stream could be further accelerated by some sort of MHD afterburner. The observation here is that a nuclear rocket is not energy limited, but rather is entropy limited: the exhaust can only carry away so much entropy. So, the goal is to make the engine as internally efficient as possible, with as little thermodynamic irreversibility as possible.
Animats 5y ago
Oh, I thought a real nuclear lightbulb. The New York Central Railroad once developed one.[1], at 8:20. [1] https://archive.org/details/0221_Big_Train_The_00_25_39_00 https://archive.org/details/0221_Big_Train_The_00_25_39_00
dr_dshiv 5y ago
Could very small wires of uranium be used to power electronics? How much plutonium would be necessary to get a 3v thermoelectric generator?

89 points by othello 5y ago

In case you can't see the original link: https://web.archive.org/web/20210130190443/https://beyondnerva.com/2020/03/21/the-nuclear-lightbulb-a-brief-introduction/ https://web.archive.org/web/20210130190443/https://beyondner...

Causality1 5y ago

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?

vangelis 5y ago
I think it be a lot like airliners vs small aircraft in terms of safety.
URSpider94 5y ago
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.
- asdff 5y ago
  On the other hand, the consequences have already been paid. There are plenty of highly irradiated places on earth already that could be used for future nuclear projects.
choeger 5y ago
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 5y ago
>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.
numpad0 5y ago
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.
ryan93 5y ago
Much cheaper than solar and wind.
7952 5y ago
As you are asking open ended questions. What do you think is an appropriate level of deaths per MWh? Can you put a number on it? And how do you engineer a reactor to accurately and repeatedly achieve a certain risk level?
- Causality1 5y ago
  Well, one answer to that is when the lives saved by nuclear balance out the lives cost by fossil fuels. Nuclear currently has a rate of 0.07 deaths per terawatt-hour. Coal has a rate of 24.6 deaths per terawatt-hour. If fully replacing coal with nuclear required making nuclear a hundred times more dangerous than it is now it would still be completely justified. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(07)61253-7/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6...
  - 7952 5y ago
    So imagine a nuclear plant that saves costs by reducing safety margins. You have less redundancy in equipment and staff, less containment, or whatever. How do you accurately predict the risk? And what error would that risk have? Every single factor you are modifying can come together in weird combinations and has an error bar of its own. What happens when there is suicidal engineer + metal fatigue + unusual weather conditions? Ultimately this seems like a fools errand. The belt-and-braces approach is the only way humans have found to safely design complex inherently risky machines. And deviating from that creates Shuttle shaped clouds in the sky and Boeing shaped holes in the ground.

tyingq 5y ago

"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_model_Easy_Bake_oven.jpg 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-following-partial-finger-amputation-consumers-urged-to-return https://www.cpsc.gov/Recalls/2007/new-easy-bake-oven-recall-...

Baeocystin 5y ago
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 5y ago
  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/uF9ffe1 https://imgur.com/a/F7WwpGg https://imgur.com/a/F7WwpGg
  - Baeocystin 5y ago
    Huh. Interesting. This would have been the late 70's/early 80's.
markc 5y ago
>Easy-Bake Oven You can buy a Panasonic FlashXpress toaster oven and get the Easy-Bake experience. Great toaster! Fast and very predictable. It starts cooking immediately and every toast cycle is the same duration. In a regular toaster oven it takes a while for the heating element to get hot before it starts to actually toast the bread. If you immediately cook a second batch of toast for the same amount of time it burns.

baybal2 5y ago

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 5y ago
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 5y ago
  Given economic considerations, both the open cycle gas core, and NSWR may beat practical Orion drives.
- jdc 5y ago
  It could make an excellent fourth stage, however.
- JulianMorrison 5y ago
  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 5y ago
    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.

philipkglass 5y ago

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 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-and-future-generation/thorium.aspx https://www.world-nuclear.org/information-library/current-an...

5y ago

Black101 5y ago

I just want a nuclear car...

Scoundreller 5y ago
“If we stop, we’ll overheat. We must go faster”.
nosmokewhereiam 5y ago
"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 5y ago
  Sure, but imagine it -- the road would be traffic-free for decades! Nevermind the trees growing in the street...
SigmundA 5y ago
A Tesla with nuclear power plants...
- Black101 5y ago
  but you have to stop to charge... I guess wireless charging is coming though
dirktheman 5y ago
Ford actually envisioned nuclear cars in the 1950s: https://en.wikipedia.org/wiki/Ford_Nucleon https://en.wikipedia.org/wiki/Ford_Nucleon

adewinter 5y ago

If anyone would like to work on a startup focused on Nuclear Propulsion, please reach out.

gloriana 5y ago
yea for sure - nuke engineer here - is it an established startup or just getting started?
transistor-man 5y ago
You got my attention, contact information is in my profile
hairytrog 5y ago
there's these guys: https://usnc.com/careers/ https://usnc.com/careers/
black6 5y ago
I'm a chemical rocket engine test engineer; I'll bite.
atdrummond 5y ago
I’m interested.
slotkin 5y ago
interesting to hear what you're working on!
gpm 5y ago
Canadian software engineer here, would be interested to hear more but if you're US based ITAR may be a problem. Email is in profile.

pfdietz 5y ago

I think you should be able to achieve an Isp approaching that of this rocket with a solid core nuclear reactor, without radiators, although at much lower T/W ratio. The idea would be to not just dump hydrogen into the reactor to heat it, but gradually warm that hydrogen, extracting as much power as one could along the way. At the end, this power would be used to superheat the hydrogen after it went through the reactor (by some sort of electrical heating), to a temperature greater than the reactor's temperature limit. Alternately, the exhaust stream could be further accelerated by some sort of MHD afterburner. The observation here is that a nuclear rocket is not energy limited, but rather is entropy limited: the exhaust can only carry away so much entropy. So, the goal is to make the engine as internally efficient as possible, with as little thermodynamic irreversibility as possible.

Animats 5y ago

Oh, I thought a real nuclear lightbulb. The New York Central Railroad once developed one.[1], at 8:20. [1] https://archive.org/details/0221_Big_Train_The_00_25_39_00 https://archive.org/details/0221_Big_Train_The_00_25_39_00

dr_dshiv 5y ago

Could very small wires of uranium be used to power electronics? How much plutonium would be necessary to get a 3v thermoelectric generator?