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Yeah but the notion that you can have a power plant which requires outside power in order to not melt-down is -- frankly -- retarded. Imagine a coal plant that

Yeah but the notion that you can have a power plant which requires outside power in order to not melt-down is -- frankly -- retarded. Imagine a coal plant that burns down 100,000 acres around it if the primary coal containment system (made up) loses power. Would anyone like that in their backyard? Or a hydro plant that if power isn't continuously supplied to, not only could the dam breach and flood downhill but also somehow miraculously uphill too (not realistic but comparative to nukes). That's what a nuclear power plant that can't slowly coast to a stop is like. I don't care how many backups and backups of backups you have, if physics isn't on your side if/when the plant loses power it's a horrible design. EDIT: a few changes for clarity

pdonis 13y ago
the notion that you can have a power plant which requires outside power in order to not melt-down is -- frankly -- retarded You're right that this is an additional risk factor, which would be eliminated in a design that required only passive cooling after shutdown (and newer designs have this feature). But "retarded" is too strong. Just having the backup generators not come on for a short time period isn't enough; they have to be unavailable for days or weeks, as the Fukushima ones were. Also, the switchgear has to be such that portable generators can't be brought in and hooked up. I was extremely surprised to find that all of those design decisions were apparently made wrong in the Fukushima plant. And even then, when put in proper perspective, the negative consequences of nuclear power are less severe, when averaged over all the kilowatt-hours of power produced by nuclear plants, than the negative consequences of other forms of energy. Coal causes far more mortality and morbidity per unit of energy generated, for example. It's not "retarded" to choose a power source that has less severe side effects all things considered. Again, that's not to say that reactor designs should not be improved. But by any reasonable standard, nuclear power even with existing designs is safer, all things considered, than other major forms of energy. The only reason the public does not understand that is that "radiation" is a buzz word, whereas "respiratory failure due to coal dust", for example, is not. (And even "radiation" is not used fairly; coal ash has higher levels of radioactivity than many forms of nuclear waste. But the public isn't exhorted to protest about radiation from coal ash.)
- msandford 13y ago
  I agree that average over the kilowatt-hours nuclear might be safer than coal. But the problem is that the risk is HIGHLY concentrated. I can self-insure my computers because if one ever fails I have the cash to handle it. It's not a financial crisis. I don't self insure my car (for collision/comprehensive) because it's too big of an expense for me to absorb at any one time without severe hardship. Nuclear reactors (as they stand today) are more like cars than computers. They tend to rob a few people of their whole lives and really eff up the ones that don't die. Coal plants have the "advantage" of robbing many people of a portion of their lives in a more subtle way. LFTR reactors have physics on their side in that if containment is lost, so is criticality. Boiling water reactors, pressurized boiling water reactors, etc in my mind can't be made safe because they require power to stay safe, even if they're not generating power. You've suggested that so long as the generators and whatnot arrive eventually, things will be fine. The problem is that you've made the assumption that somehow, some way the generators will arrive and the reactor can be made safe again over the course of some weeks or months. Nuclear reactors are one of the few pieces of infrastructure that can't simply be abandoned if something bad happens, or else the problem gets worse and worse and worse. This is a positive feedback cycle rather than a negative one. Positive feedback often "blows up" (a term we use in electrical engineering) or grows without bound. Nearly everything else in modern society functions with negative feedback and that kind of intrinsic safety is what most people want. That's not to say that ALL nuclear reactors are by definition unsafe; just all the ones that are currently operating commercially because it's such a nightmare to permit new designs and the existing manufacturers have no interest in inviting competitors into their market.
  - dllthomas 13y ago
    Frankly, I think the concentrated, visible threat is better. We're much better at dealing with those.
  - pdonis 13y ago
    LFTR reactors have physics on their side in that if containment is lost, so is criticality. But loss of criticality isn't sufficient for the reactor to be "safe". Even with the reactor no longer critical, there are still a lot of radioactive fission products left. The way to prevent them from escaping is secondary containment, which Chernobyl did not have, as I said (Fukushima, and indeed every other reactor ever built that wasn't built by the Soviet Union, has secondary containment). Of course, as Fukushima illustrated, secondary containment is not the only necessary feature for safety. You also need decay heat cooling. The key advantage of a design like LFTR, as compared to a design like Fukushima, is passive decay heat cooling; simple thermodynamics is sufficient to keep the fission products contained and cooled after shutdown. That's why such reactors don't, in your words, "require power to stay safe, even if they're not generating power". However, LFTR is not the only possible design with passive decay heat cooling; there are ordinary pressurized water reactor designs that have passive decay heat cooling (by designing the piping circuits and placing the heat exchangers and core to take advantage of natural convection). Fukushima was not such a design, but they do exist (although AFAIK they didn't when Fukushima was built). Nuclear reactors are one of the few pieces of infrastructure that can't simply be abandoned if something bad happens, or else the problem gets worse and worse and worse. This is true, but it's just as true of passively cooled designs like LFTR. The problem here is what to do with the highly radioactive fission products. The way every nuclear-using country except the US deals with this is reprocessing: you take the spent fuel, separate out what's still fissionable (which is a pretty large fraction of it with most current designs), and put what remains through a special reactor that converts the fission products to either much longer-lived (and hence much less radioactive) or stable isotopes. Problem solved. France and Japan have been doing this at scale for several decades now. The only reason the US doesn't is politics.

pdonis 13y ago

the notion that you can have a power plant which requires outside power in order to not melt-down is -- frankly -- retarded You're right that this is an additional risk factor, which would be eliminated in a design that required only passive cooling after shutdown (and newer designs have this feature). But "retarded" is too strong. Just having the backup generators not come on for a short time period isn't enough; they have to be unavailable for days or weeks, as the Fukushima ones were. Also, the switchgear has to be such that portable generators can't be brought in and hooked up. I was extremely surprised to find that all of those design decisions were apparently made wrong in the Fukushima plant. And even then, when put in proper perspective, the negative consequences of nuclear power are less severe, when averaged over all the kilowatt-hours of power produced by nuclear plants, than the negative consequences of other forms of energy. Coal causes far more mortality and morbidity per unit of energy generated, for example. It's not "retarded" to choose a power source that has less severe side effects all things considered. Again, that's not to say that reactor designs should not be improved. But by any reasonable standard, nuclear power even with existing designs is safer, all things considered, than other major forms of energy. The only reason the public does not understand that is that "radiation" is a buzz word, whereas "respiratory failure due to coal dust", for example, is not. (And even "radiation" is not used fairly; coal ash has higher levels of radioactivity than many forms of nuclear waste. But the public isn't exhorted to protest about radiation from coal ash.)

msandford 13y ago
I agree that average over the kilowatt-hours nuclear might be safer than coal. But the problem is that the risk is HIGHLY concentrated. I can self-insure my computers because if one ever fails I have the cash to handle it. It's not a financial crisis. I don't self insure my car (for collision/comprehensive) because it's too big of an expense for me to absorb at any one time without severe hardship. Nuclear reactors (as they stand today) are more like cars than computers. They tend to rob a few people of their whole lives and really eff up the ones that don't die. Coal plants have the "advantage" of robbing many people of a portion of their lives in a more subtle way. LFTR reactors have physics on their side in that if containment is lost, so is criticality. Boiling water reactors, pressurized boiling water reactors, etc in my mind can't be made safe because they require power to stay safe, even if they're not generating power. You've suggested that so long as the generators and whatnot arrive eventually, things will be fine. The problem is that you've made the assumption that somehow, some way the generators will arrive and the reactor can be made safe again over the course of some weeks or months. Nuclear reactors are one of the few pieces of infrastructure that can't simply be abandoned if something bad happens, or else the problem gets worse and worse and worse. This is a positive feedback cycle rather than a negative one. Positive feedback often "blows up" (a term we use in electrical engineering) or grows without bound. Nearly everything else in modern society functions with negative feedback and that kind of intrinsic safety is what most people want. That's not to say that ALL nuclear reactors are by definition unsafe; just all the ones that are currently operating commercially because it's such a nightmare to permit new designs and the existing manufacturers have no interest in inviting competitors into their market.
- dllthomas 13y ago
  Frankly, I think the concentrated, visible threat is better. We're much better at dealing with those.
- pdonis 13y ago
  LFTR reactors have physics on their side in that if containment is lost, so is criticality. But loss of criticality isn't sufficient for the reactor to be "safe". Even with the reactor no longer critical, there are still a lot of radioactive fission products left. The way to prevent them from escaping is secondary containment, which Chernobyl did not have, as I said (Fukushima, and indeed every other reactor ever built that wasn't built by the Soviet Union, has secondary containment). Of course, as Fukushima illustrated, secondary containment is not the only necessary feature for safety. You also need decay heat cooling. The key advantage of a design like LFTR, as compared to a design like Fukushima, is passive decay heat cooling; simple thermodynamics is sufficient to keep the fission products contained and cooled after shutdown. That's why such reactors don't, in your words, "require power to stay safe, even if they're not generating power". However, LFTR is not the only possible design with passive decay heat cooling; there are ordinary pressurized water reactor designs that have passive decay heat cooling (by designing the piping circuits and placing the heat exchangers and core to take advantage of natural convection). Fukushima was not such a design, but they do exist (although AFAIK they didn't when Fukushima was built). Nuclear reactors are one of the few pieces of infrastructure that can't simply be abandoned if something bad happens, or else the problem gets worse and worse and worse. This is true, but it's just as true of passively cooled designs like LFTR. The problem here is what to do with the highly radioactive fission products. The way every nuclear-using country except the US deals with this is reprocessing: you take the spent fuel, separate out what's still fissionable (which is a pretty large fraction of it with most current designs), and put what remains through a special reactor that converts the fission products to either much longer-lived (and hence much less radioactive) or stable isotopes. Problem solved. France and Japan have been doing this at scale for several decades now. The only reason the US doesn't is politics.