4 ms·

Nuclear reactors in cars are a bad idea. Even if they can be built small and never needed refueling, cars get destroyed in all imaginable ways all the time, so

by madez 7y ago

Nuclear reactors in cars are a bad idea. Even if they can be built small and never needed refueling, cars get destroyed in all imaginable ways all the time, so the nuclear pollution would need to be expected to be released often. Also, we don't have a solution for the contaminated waste that millions of nuclear powered cars would produce. We can satisfy our power needs from renewable sources with existing technology to competitive prices.

The_rationalist 7y ago
such predictable answers... The same schema repeat over and over. Let me be clear, what you say is mostly not wrong, but misleading. Your comment understate the importance, the necessity of quantification. "never needed refueling" Wouldn't that be fascinating? "cars get destroyed in all imaginable ways all the time" Right. "so the nuclear pollution would need to be expected to be released often" Yes BUT can we have a little bit of intellectual riguor and admit that we must quantify how much dangerous that would be. Let's keep in mind that a nuclear car having an accident != a new chernobyl. Being at most a kilowatt reactor make it order of magnitude less radioactive. I Guess (wishful thinking maybe) that the radiations would be far less dangerous and more local than is explosion and fire from current car crashs. But I want a nuclear expert to show me a calculus that would show if the dangerosity is negligible or higher (how much) than current crashs. The thing is, such experts will not read this thread and even if there were a scientific consensus on whether it's probably safer, democracy would be order of magnitudes too dumb / ignorant to vote for it. BTW the numbers of death due to C02 emissions should be taken into account too. "we don't have a solution for the contaminated waste that millions of nuclear powered cars would produce." How do you know that? There's 0 funding to experiment solutions in the first place. But I expect it to be trivial. Current wastes are trivially contained in safe places. They do not need maintenance. Do you know how much a nuclear reactor produce waste per year? I did, I don't remember the exact number, but it was like a few kilos at most. So for a micro reactor in a car it should be a few grams at most. Which should be recuperated at the end of life of the car (if not negligible). I've not even talked about nuclear advances such as reusing the wastes or provably safe reactors which necessarily auto shutdown by design. This already exists, but democratize very slowly due to lack of funding because of irrational politics driven by hysterical people fear (did you know that nuclear was both cleaner than solar AND safer (yes solar killed more people statistically). "We can satisfy our power needs from renewable sources with existing technology to competitive prices." Wishfull thinking? Firstly solar does not scales well, is not autosuffisant, it fascinatingly less efficient than nuclear (did you remark that solar is indirectly catching the output of a nuclear (fusion) energy AKA the sun?) But the fact is, electric cars are a lie. They will drive no pun intended a penury in Lithium which is necessary for efficient batteries which will be dramatic. Nuclear cars would not need batteries or only small batteries. Thanks for reading.
- xzvXSvz 7y ago
  ""never needed refueling" Wouldn't that be fascinating?" The act of refueling is not a problem in ICE cars. It's arguably their greatest advantage (only?) over electric ones. " I Guess (wishful thinking maybe) that the radiations would be far less dangerous and more local than is explosion and fire from current car crashs." And you'd be guessing wrong. A breach in the containment would be catastrophic for the whole neighborhood, if not city, for decades. " The thing is, such experts will not read this thread " Actually nuclear experts do, sometimes, show up. " But I want a nuclear expert to show me a calculus that would show if the dangerosity is negligible or higher (how much) than current crashs." Buy Lamarsh's book. It has all the calculus you want. Amazon has it for less than $40. I myself have a copy in my basement and it's a good book. " reusing the wastes or provably safe reactors which necessarily auto shutdown by design" I don't know much about breeders ("reusing" waste reactors), but I doubt you could contain the neutrons of fast reactor. No design is "provably" safe (this isn't 10 LOC run through Coq). The industry uses the term "inherently" safe or, better, "passively" safe. It typically refers to the reactor power naturally tending to zero if the safety mechanisms fail. If you crash into cement barrier, though, all bets are off. ""we don't have a solution for the contaminated [...] But I expect it to be trivial" and you'd be wrong. Waste management is the number one problem of the industry. "but it was like a few kilos at most" Actually it's in the tons, you're confusing waste with mass that no longer exists as it became energy. 1Kg is the amount of mass that became energy through E=mc^2 (try it: 1GWe reactor @ 0.3% thermal efficiency running for 365243600 s = 1.05E17 Ws = m * c^2 -> m = 1 Kg) But that's only about 0.1% of the total mass of fuel and waste... therefore tons! " So for a micro reactor in a car it should be a few grams at most" It doesn't scale linearly. "This already exists, but democratize very slowly due to lack of funding because of irrational politics driven by hysterical people fear " A patronizing attitude towards people's fears mixed with general ignorance on the subject doesn't bode well.
- jasonwatkinspdx 7y ago
  You don't need a nuclear expert, just around a high school physics class understanding of what's going on. From https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/radwaste.html#waste https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/r... > High-level wastes are hazardous because they produce fatal radiation doses during short periods of direct exposure. For example, 10 years after removal from a reactor, the surface dose rate for a typical spent fuel assembly exceeds 10,000 rem/hour – far greater than the fatal whole-body dose for humans of about 500 rem received all at once. And that's for fuel that's been run in commercial reactors, which is commonly only 5% enriched. The NASA reactor uses 90% enriched fuel. Once that thing is turned on it will become deadly for centuries. Any breach of containment during a car crash would be instantly lethal for a considerable distance. Using a robot to extract the core from the wreck and place it in new containment would be a very non trivial task taking days if not weeks. The idea of putting a kilopower reactor in a car is a total non starter, and not because people lack 'rationality' or aren't as smart as you think you are.

by madez 7y ago

The_rationalist 7y ago

such predictable answers... The same schema repeat over and over. Let me be clear, what you say is mostly not wrong, but misleading. Your comment understate the importance, the necessity of quantification. "never needed refueling" Wouldn't that be fascinating? "cars get destroyed in all imaginable ways all the time" Right. "so the nuclear pollution would need to be expected to be released often" Yes BUT can we have a little bit of intellectual riguor and admit that we must quantify how much dangerous that would be. Let's keep in mind that a nuclear car having an accident != a new chernobyl. Being at most a kilowatt reactor make it order of magnitude less radioactive. I Guess (wishful thinking maybe) that the radiations would be far less dangerous and more local than is explosion and fire from current car crashs. But I want a nuclear expert to show me a calculus that would show if the dangerosity is negligible or higher (how much) than current crashs. The thing is, such experts will not read this thread and even if there were a scientific consensus on whether it's probably safer, democracy would be order of magnitudes too dumb / ignorant to vote for it. BTW the numbers of death due to C02 emissions should be taken into account too. "we don't have a solution for the contaminated waste that millions of nuclear powered cars would produce." How do you know that? There's 0 funding to experiment solutions in the first place. But I expect it to be trivial. Current wastes are trivially contained in safe places. They do not need maintenance. Do you know how much a nuclear reactor produce waste per year? I did, I don't remember the exact number, but it was like a few kilos at most. So for a micro reactor in a car it should be a few grams at most. Which should be recuperated at the end of life of the car (if not negligible). I've not even talked about nuclear advances such as reusing the wastes or provably safe reactors which necessarily auto shutdown by design. This already exists, but democratize very slowly due to lack of funding because of irrational politics driven by hysterical people fear (did you know that nuclear was both cleaner than solar AND safer (yes solar killed more people statistically). "We can satisfy our power needs from renewable sources with existing technology to competitive prices." Wishfull thinking? Firstly solar does not scales well, is not autosuffisant, it fascinatingly less efficient than nuclear (did you remark that solar is indirectly catching the output of a nuclear (fusion) energy AKA the sun?) But the fact is, electric cars are a lie. They will drive no pun intended a penury in Lithium which is necessary for efficient batteries which will be dramatic. Nuclear cars would not need batteries or only small batteries. Thanks for reading.

xzvXSvz 7y ago
""never needed refueling" Wouldn't that be fascinating?" The act of refueling is not a problem in ICE cars. It's arguably their greatest advantage (only?) over electric ones. " I Guess (wishful thinking maybe) that the radiations would be far less dangerous and more local than is explosion and fire from current car crashs." And you'd be guessing wrong. A breach in the containment would be catastrophic for the whole neighborhood, if not city, for decades. " The thing is, such experts will not read this thread " Actually nuclear experts do, sometimes, show up. " But I want a nuclear expert to show me a calculus that would show if the dangerosity is negligible or higher (how much) than current crashs." Buy Lamarsh's book. It has all the calculus you want. Amazon has it for less than $40. I myself have a copy in my basement and it's a good book. " reusing the wastes or provably safe reactors which necessarily auto shutdown by design" I don't know much about breeders ("reusing" waste reactors), but I doubt you could contain the neutrons of fast reactor. No design is "provably" safe (this isn't 10 LOC run through Coq). The industry uses the term "inherently" safe or, better, "passively" safe. It typically refers to the reactor power naturally tending to zero if the safety mechanisms fail. If you crash into cement barrier, though, all bets are off. ""we don't have a solution for the contaminated [...] But I expect it to be trivial" and you'd be wrong. Waste management is the number one problem of the industry. "but it was like a few kilos at most" Actually it's in the tons, you're confusing waste with mass that no longer exists as it became energy. 1Kg is the amount of mass that became energy through E=mc^2 (try it: 1GWe reactor @ 0.3% thermal efficiency running for 365243600 s = 1.05E17 Ws = m * c^2 -> m = 1 Kg) But that's only about 0.1% of the total mass of fuel and waste... therefore tons! " So for a micro reactor in a car it should be a few grams at most" It doesn't scale linearly. "This already exists, but democratize very slowly due to lack of funding because of irrational politics driven by hysterical people fear " A patronizing attitude towards people's fears mixed with general ignorance on the subject doesn't bode well.
jasonwatkinspdx 7y ago
You don't need a nuclear expert, just around a high school physics class understanding of what's going on. From https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/radwaste.html#waste https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/r... > High-level wastes are hazardous because they produce fatal radiation doses during short periods of direct exposure. For example, 10 years after removal from a reactor, the surface dose rate for a typical spent fuel assembly exceeds 10,000 rem/hour – far greater than the fatal whole-body dose for humans of about 500 rem received all at once. And that's for fuel that's been run in commercial reactors, which is commonly only 5% enriched. The NASA reactor uses 90% enriched fuel. Once that thing is turned on it will become deadly for centuries. Any breach of containment during a car crash would be instantly lethal for a considerable distance. Using a robot to extract the core from the wreck and place it in new containment would be a very non trivial task taking days if not weeks. The idea of putting a kilopower reactor in a car is a total non starter, and not because people lack 'rationality' or aren't as smart as you think you are.