The title is technically correct; however, it seems like link bait once you get to page two of the article and see:
"Bridenbaugh told ABC News that he believes the design flaws that prompted his resignation from GE were eventually addressed at the Fukushima Daiichi plant."
Yes, but he hesitated to say this was sufficient and said the reactors were still "a little more susceptible to an accident that would result in a loss of containment".
The qualitative assessment of the plant's design is outside the scope of what I'm commenting on. I'm referring to the journalistic bait-and-switch which hides a very relevant piece of information (that contradicts the implied assertion of the title) on page two of a banner-encrusted site.
In the context of current events, the title of the link suggests some kind of spectacular negligence.
At the point where the scientist says the design flaws were addressed, [his resignation due to design flaws] is no longer a story that adds anything relevant or noteworthy to the discussion. It's merely a historical fact disconnected from current events.
If the title of the article had followed the content and been focused on the expert sharing their knowledge and discussing possible problems with the design I would have appreciated it much more.
Dear downvoter, would you buy a car that falls apart (or blows up killing the passengers) when it runs out of gas?
If something can go wrong, it will, given time, go wrong. Even if there is one chance in a million for the whole chain of countermeasures to fail in tandem, give it a million chances to happen and you end up with a good chance of it happening.
Indeed there are, but one could suppose nuclear reactors would only fail catastrophically when something catastrophic happened, not when being shut down.
I would call an earthquake (which was larger than it was designed to withstand) followed by a tsunami (which knocked out the emergency generators) pretty catastrophic.
It was designed to shut down during a quake, something it did. What bothers me is that something that generates so much heat as to require active cooling (something that already indicates less than ideal operating conditions) requires an external system to cool it. The first option should always be to use the reactor to generate power to operate the pumps that cool it. A small turbine mechanically connected to the pumps would be a better option. Operating the cooling system doesn't require more than a tiny fraction of the post-shutdown thermal output.
I am fine with having the independent generators to operate cooling pumps in an emergency shutdown, but I am not very enthusiastic as they being the first line of defense.
There are some situations where risk may be acceptable.
Would I accept a car that blows up when it runs out of gas? No, but things like airplanes can, and have, killed passengers when they run out of gas. The risk of that happening is offset by the need to occasionally travel faster or farther than a car can take you.
I still think nuclear power is worth the risks of accidents, but I don't think that the proponents of nuclear power have been entirely honest about its safety.
Up until a week ago I was one of those people who would swear up and down that the technology is safe and would shut itself down in the event of an accident, and that all the previous incidents were due to human error anyway. No more. I actually feel stupid for believing that stuff now.
> There are some situations where risk may be acceptable.
There are. This is just not one of them. Better: this one involves unacceptable risks derived from inadequate engineering. A nuclear reactor that requires an external source or energy to dissipate the (prodigious amount of) energy it generates after shut down is stupid. Sorry to all engineers involved in this, but I can't find another word. Maybe adequate cooling would make the reactor cost twice as much. Maybe it would take up too much space. Or maybe it would require the reactor to be impossibly compact. Or big. I don't care. If it doesn't work (and it's quite clear this one isn't) it's because the design is not ready. It may not be your fault - it may be so due to what the client demanded, both in cost and space constraints, but that's what professional ethics are for. I have walked out of projects and companies before. This disaster shows not nearly enough engineers did the same.
I agree with you -- actually go a step further and replace "weird" with "irresponsible" and that's how I feel about the whole situation.
There are newer generations of nuclear reactors that don't suffer from this design flaw, but convincing the public that nuclear power can be done safely is going to get a lot more difficult. This incident is going to be a huge step backwards for public acceptance of nuclear power.
In short, even after reactor shutdown, substantial heat is still produced, so some cooling is needed. Substantial as in, up to some 7% of normal output, early after the shutdown. That's mostly due to residue fissible elements -- byproduct of normal operation.
The explosion was not inside reactor pressure vessel, but in the housing. Top parts of fuel rods got exposed out of coolant water at some point and heated up considerably. When water level was raised back again, heat caused release hydrogen. Upon subsequent steam venting (necessary in case of overheating), the hydrogen combusted in the air in reactor housing (i.e., building, not the pressure vessel itself). The pressure vessel itself contains no air to avoid explosion.
Compare a very early mishap with a nuclear pile (not reactor): http://en.wikipedia.org/wiki/Windscale_fire -- where the Brits tried to extinguish smoldering graphite & very hot fuel with water, and there was risk of hydrogen explosion (fortunately avoided).
It just seems odd that the core still generates heat enough to damage itself (50 MW is a lot) but that the heat cannot be used to operate the pumps that should cool it down.
The embedded video was American scare-journalism at its finest. Workers at a compromised nuclear site wearing full suits and masks? Why, that's just like CHERNOBYL!
20 comments
[ 0.23 ms ] story [ 46.3 ms ] thread"Bridenbaugh told ABC News that he believes the design flaws that prompted his resignation from GE were eventually addressed at the Fukushima Daiichi plant."
In the context of current events, the title of the link suggests some kind of spectacular negligence.
At the point where the scientist says the design flaws were addressed, [his resignation due to design flaws] is no longer a story that adds anything relevant or noteworthy to the discussion. It's merely a historical fact disconnected from current events.
If the title of the article had followed the content and been focused on the expert sharing their knowledge and discussing possible problems with the design I would have appreciated it much more.
[edit: clarify what is no longer newsworthy]
Anyway, a design that blows up when power is cut because it cannot cool itself down to safe levels is... weird.
If something can go wrong, it will, given time, go wrong. Even if there is one chance in a million for the whole chain of countermeasures to fail in tandem, give it a million chances to happen and you end up with a good chance of it happening.
Shutting down after a tsunami took out much of the support equipment seems somewhat catastrophic.
I am fine with having the independent generators to operate cooling pumps in an emergency shutdown, but I am not very enthusiastic as they being the first line of defense.
Would I accept a car that blows up when it runs out of gas? No, but things like airplanes can, and have, killed passengers when they run out of gas. The risk of that happening is offset by the need to occasionally travel faster or farther than a car can take you.
I still think nuclear power is worth the risks of accidents, but I don't think that the proponents of nuclear power have been entirely honest about its safety.
Up until a week ago I was one of those people who would swear up and down that the technology is safe and would shut itself down in the event of an accident, and that all the previous incidents were due to human error anyway. No more. I actually feel stupid for believing that stuff now.
There are. This is just not one of them. Better: this one involves unacceptable risks derived from inadequate engineering. A nuclear reactor that requires an external source or energy to dissipate the (prodigious amount of) energy it generates after shut down is stupid. Sorry to all engineers involved in this, but I can't find another word. Maybe adequate cooling would make the reactor cost twice as much. Maybe it would take up too much space. Or maybe it would require the reactor to be impossibly compact. Or big. I don't care. If it doesn't work (and it's quite clear this one isn't) it's because the design is not ready. It may not be your fault - it may be so due to what the client demanded, both in cost and space constraints, but that's what professional ethics are for. I have walked out of projects and companies before. This disaster shows not nearly enough engineers did the same.
There are newer generations of nuclear reactors that don't suffer from this design flaw, but convincing the public that nuclear power can be done safely is going to get a lot more difficult. This incident is going to be a huge step backwards for public acceptance of nuclear power.
In short, even after reactor shutdown, substantial heat is still produced, so some cooling is needed. Substantial as in, up to some 7% of normal output, early after the shutdown. That's mostly due to residue fissible elements -- byproduct of normal operation.
The explosion was not inside reactor pressure vessel, but in the housing. Top parts of fuel rods got exposed out of coolant water at some point and heated up considerably. When water level was raised back again, heat caused release hydrogen. Upon subsequent steam venting (necessary in case of overheating), the hydrogen combusted in the air in reactor housing (i.e., building, not the pressure vessel itself). The pressure vessel itself contains no air to avoid explosion.
Compare a very early mishap with a nuclear pile (not reactor): http://en.wikipedia.org/wiki/Windscale_fire -- where the Brits tried to extinguish smoldering graphite & very hot fuel with water, and there was risk of hydrogen explosion (fortunately avoided).