Posted on 03/29/2011 5:46:13 PM PDT by Kaslin
It was more than just the emergency generators. It is likely that a good amount of the electrical switchgear that powers the various pumps, lighting, and instrumentation was damaged as well. I say this because when they were bringing power back to units 1-4, there was mention of temporary substations and distribution panels. So in other words, it isn't necessarily the generators themselves that got wiped in the tsunami, but the equipment to which they were connected.
Also, although I can't confirm it, I heard from another couple of posters that the fuel tanks for the diesel generators associated with 1-4 were wiped out by the tsunami.
At any rate, loss of AC power was the big problem at Fukushima Diiachi, units 1-4. And that illustrates the weakest link in these plants.
Sorry! The EPA is in the process of shutting down coal fired plants.
The diesel generators and the switchgear operated for two hours following the tsunami. That means the diesels probably shutdown after the linited fuel in the day tanks was exhausted. The question is why weren’t the day tanks refilled from the main storage tanks.
That's where things are sketchy for me. I heard that they ran for an hour, and I also heard that they ran until the tsunami caused them to trip.
The "day tank" idea is plausable. Perhaps they didn't expect such a huge tsunami, having never experienced one before, so they never bothered to top off the day tanks. Once the main tanks got wiped, they were finished. Alternatively, maybe they were in the process of transferring fuel to the day tanks, but started on unit 6 (which either kept a single diesel on line, or regained it very quickly) at the other end of the plant property.
Frankly, I think that they were caught with their pants down just a bit, since this was an unprecidented event. I'm also certain that they had their hands full already when 1-3 scrammed because of the earthquake. The tsunami was the icing on the cake.
Yeah, we’d be talking about the Sierra Nevada Islands.
Unfortunately, you are right. And a lot of their audience would not know any different.
Getting a tsunami all the way to the mountains of rural Nevada is an engineering problem that most greenies would not touch. The potential of a Fukushima-style incident would be the limit of what they can understand and focus on.
A DAY Tank, by definition is good for that long. The twinned 3 MW gensets I am responsible for will run for 26 hours on the "DAY" tanks assigned them. What happened in Japan is: the "day" tanks, the gensets, and the related switchgear itself were all WASHED AWAY in a wholly unprecedented and unanticipated by ANYONE, even in a worst-case-scenario, event.
To further refute your alleged "information" regarding the reactor incident in Japan, even though the PRIMARY backup system failed after one hour (when the tsunami hit), the secondary (battery) system kicked in right on schedule, powering the pumps for another EIGHT hours, until the battery system too failed, due to lack of recharge. NINE HOURS of backup power was there, but no-one ever thought that another power source COULDN'T avail itself before the auxiliaries were exhausted.
That the reactors, spent fuel pools and secondary containment structures have done so well in spite of the several orders of magnitude worse than expected events of last month is a TESTAMENT to the SAFETY of nuclear power!
The reactors in question were of 40+ year old design and were about to be phased out and replaced with newer, more modern and safer designed reactors. Your posts show how full of fear and misinformation the public is regarding nuclear power, which is the ULTIMATE in carbon-free electricity.
I agree that the hype about what’s happening at the reactor sites is being hyped beyond the actual danger.
I could not help but admire those who designed these and those, after the Tusami, keeping things going...by hand in the dark...without a meltdown completely. Really quite amazing these are still standing as are and maintained as they are...amazing courage and fortitude in light of great danger for these workers!
That is not to say there is danger...but it’s just being so overblown.
OH, BTW, where I work, the “Day” tanks are AUTOMATICALLY refilled from the main tanks when they reach the 40% full/60%empty mark. The valves open, the pumps start, and the day tanks are refilled to 85%, then the pumps shut down, even if the gensets are running. If there is insufficient fuel in the main tank, *I* get an alarm and , well, there better be a GOOD reason why I didn’t have fuel there.
Any operator in the control room can override this parameter, but there has never in my experience been any reason to override the level controller during non-emergent conditions.
Convenient, isn’t it? Every form of energy is unavailable to us EXCEPT OPEC oil.
Curious, isn’t it?
What we seem to have forgotten is the danger these cooling pools presents as a target for terrorists. Immediately after 9/11 there were multiple studies which investigated thye vulnerabilities of our nuclear plants, and thye associated cooling pools to attack by aircraft. All this seemed to vanish when the new regime took power.
If you are still in doubt visit
http://cryptome.org/index.html and scroll down to “US Nuclear Spent Fuel Storage Casks Eyeball”. There you’ll find pictures, coordinates, and design of hundreds of potential targets - and it might take less than an airlines to open them up.
Thank you Reid, Obama and Chu.
Don, I worked in the nuclear industry for over twenty years. During that period I was involved in the design and maintenance in some capacity at over twenty nuclear power plants including one that has the same generation reactor setup as the one in Japan. I’m not sure what fear you’re talking about. The design at Japan did resist the forces beyond the design limits.
My sources indicated the DGs started and ran as exactly as required when offsite power was lost. That would seem to indicate a fuel problem later when they shutdown and the plant switched to the batteries.
I haven’t read that any of the DGs were washed away. Typically those are housed in a bunker. Please post a link to any report stating the DGs were washed away. You’re the first that I’ve heard make that statement.
I exaggerated, I guess. The "fear" I was referring to is the hysteria being whipped up by the press and enviro-nuts over the nuclear products being detected across the sea in North America and in China, not anything you said.
.........................What happened in Japan is: the “day” tanks, the gensets, and the related switchgear itself were all WASHED AWAY in a wholly unprecedented and unanticipated by ANYONE, even in a worst-case-scenario, event........................
Which gets back to my main point, posted at #20, the entire power backup problem gets back to flawed facility design.
If the genset may have been designed to be on high ground (which if questionable, why would all other gear beside a day tank be vulernable to water damage?
If a heavy diesel tank, fuel filters etc. and all related switching gear can’t be sited at the same higher altitude, and then using overhead transmission lines to provide power into the massive containment facility, then who are the engineers that provide the “failsafe” designs??
New Orleans was lost because low sited generators were innundated by Katrina water, knocking out the massive pumps.
Our worlds press will lose our nuclear power option, not because of poor reactor design, but because emergency pumps, their systems, and their fuel supplies were improperly placed too close to sea level.
The most viable of power options will be vilified for many more decades.
I want the Yucca facility built just to spite Nevada democrats.
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