Japan earthquake + tsunami + nuclear problems

manofthesea said:
Why is the evacuation zone growing larger? Six miles was supposed to be a safe distance.
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It could be precautionary. Under the current situation, there is little reason to keep people in place and no one is going to be faulted for being excessively cautious.
 
Chaos said:
For clarification... a "design basis event" or "design basis accident" is something the thing is supposed to weather without suffering untoward consequences, correct?
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Essentially yes...the plant may not survive and have to remain shutdown for ever like TMI...but no one would get hurt and radiation released would be inconsequential. In general, the assumption is a large break/problem in the reactor plant, coupled with a loss of offsite power and a single random failure. All the analysis should say, the fuel is OK and little to no radiation release. TMI proved the calcs were conservative but we needed to improve some things. We now take into account a wider variety of accident scenarios and also have upgraded monitoring equipment to survive any accident better. Plus a few new things: Hydrogen production problem that occured at TMI was not accounted for in the past. Hydrogen recombiners have been backfitted into all plants in the US and is included in new designs.

glenn
 
Given the very high percentage of Japan's domestic and industrial power which comes from nuclear plants, those with ecological concerns might want to calculate how much oil or coal equivalent would have been burned since the 1970s to provide the same energy output.
 
manofthesea said:
Would alternative energy power plants be as dangerous?
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There is no 'alternative energy' source which is anywhere near ready for prime time (24/7 predictable and controllable capacity). Keeping the consistent power levels needed for modern civilization can only be currently done with nuclear or fossil.

It has already been statistically demonstrated that coal plant emissions cause more deaths than nuclear plants.
 
jayh said:
There is no 'alternative energy' source which is anywhere near ready for prime time (24/7 predictable and controllable capacity). Keeping the consistent power levels needed for modern civilization can only be currently done with nuclear or fossil.

It has already been statistically demonstrated that coal plant emissions cause more deaths than nuclear plants.
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So far....
 
On another forum (a sports one, of all things), one of the poster's fathers is in the nuke engineering industry here in the US. And he was saying that word from the grapevine is that the engineers at Fukushima abandoned their posts before shutting the reaction down when the tsunami warning came in. Here's his post:
Fukushima I, which was built in the 70’s as previously stated, was the only plant in Japan that did NOT enact SCRAM procedures for automatic shutdown. Heads are going to roll because of this, but it seems most of the operators and contractors took off running with the evacuation warning, which is a huge no-no. They left the plant operational without doing a full shutdown. When the Tsunami came in it knocked out all power to the plant and knocked out the backup diesel generators. While the containment dome was not damaged from the earthquake or tsunami, the generator being knocked out resulted in a loss of coolant flow to the reactor core. This is one of the worst case scenarios in hypothetical situations, and without power to the core, and no operators on site, the control rods weren’t dropped to SCRAM the reactor. The core continued to heat up, and early this morning (for us) a subsequent earthquake detonated the diesel generator and all of the fuel causing a massive explosion next to the reactor containment dome. While it is unclear why the dome did not withstand the blast, the current theory is the combination of multiple earthquakes/tremors, the tsunami, and the massive explosion all contributed. Anyway, the containment dome cracked, releasing a small amount of Cesium into the atmosphere (that would be the radiation spike). The plant operators have been flooding the core structure with coolant in an attempt to continue to cool the core. Since power is still out they are unable to release the control rods and so they are simply flooding the containment chamber until a backup generator can be brought on site to restore limited power.
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How much of that is confirmed? I don't know. It's all thirdhand. But nothing I've seen in the news contradicts any of that. At any rate, if this guy's father is correct, then the only reason this is an issue at all is because that one plant's crew didn't shut things down before fleeing the tsunami.

Now, can anyone blame them? I have no idea. I don't know how long it takes to shut a core down. For all I know, they thought they only had seconds to survive, so therefore fled. It's simply unclear. But the implication is that the procedure in case of emergency was to do the shutdown and only then leave, so the charge being made is that the ultimate, originating problem here was human error. It'll be interesting to see in the upcoming weeks and months how accurate this claim ends up being.
 
ElMondoHummus said:
On another forum (a sports one, of all things), one of the poster's fathers is in the nuke engineering industry here in the US. And he was saying that word from the grapevine is that the engineers at Fukushima abandoned their posts before shutting the reaction down when the tsunami warning came in. Here's his post:


How much of that is confirmed? I don't know. It's all thirdhand. But nothing I've seen in the news contradicts any of that. At any rate, if this guy's father is correct, then the only reason this is an issue at all is because that one plant's crew didn't shut things down before fleeing the tsunami.

Now, can anyone blame them? I have no idea. I don't know how long it takes to shut a core down. For all I know, they thought they only had seconds to survive, so therefore fled. It's simply unclear. But the implication is that the procedure in case of emergency was to do the shutdown and only then leave, so the charge being made is that the ultimate, originating problem here was human error. It'll be interesting to see in the upcoming weeks and months how accurate this claim ends up being.
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the post you have included as a quote is baloney...not much to do with actual events. the wiki article is reasonable.

The rods in a BWR don't drop...they are inserted with high pressure air into the bottom of the core...which did occur and would occur automatically

http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant

glenn
 
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MG1962 said:
Wow tough crowd - One of the largest earthquakes ever to hit the planet, the island the reactors are on moved 8 feet the planet moved 4 inches on its axis
I am no real fan of nuclear energy but I defy anyone to explain to me how engineers could have built these things any better. Sometime events are of a magnitude no engineer can design against
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Given the magnitude (pardon the pun) of the disaster, I think the nuke plants are holding up pretty well.

Btw, do you have a source for the hilighted part?
 
Shutdowns are computer controlled so that it is NOT NECESSARY for a human to stay there the whole time.
 
The latest:

http://www.guardian.co.uk/world/2011/mar/12/japan-earthquake-tsunami-aftermath-live

Reuters reports that the Fukushima nuclear plant has also lost the emergency cooling system at its No 3 reactor, according to the Japan Nuclear and Industrial Safety Agency. This requires the facility to urgently secure a means to supply water to the reactor a Japanese official said. The safety agency also warned that the number of individuals exposed to radiation from the plant could reach as high as 160.

Meanwhile Associated Press is reporting the International Atomic Energy Agency as saying that Japan is evacuating 170,000 people from the area around the Fukushima nuclear plant.
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Kuko 4000 said:
I do have to wonder why the Japanese were not prepared for this when other countries have warned them about this and know how to build better precautionary measures. What do you guys think would be the worst that could realistically come from this?
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I don't think we have all the facts yet, so jumping to conclusions about whether or not "better precautionary measures" are needed is premature, in my opinion.

As for your question, the absolute worst-case scenario that I can imagine is another Chernobyl... but that is really, really, REALLY stretching it; and, almost three decades later, it seems the long term damage done by Chernobyl isn't as bad as feared originally. My guess is that the Japanese government is being overly cautious (totally understandable) and that ecological damage & radiation release will be relatively small. In other words: sorry, no Godzilla :p
 
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MattusMaximus said:
Thanks, I haven't really been following the news on this much at all.

On another note, it never ceases to amaze me just how powerful earthquakes can be - wow :jaw-dropp
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That's why it bugs me that so many armchair experts are complaining about Japanese readiness and rescue efforts. There is just so much destruction of different types that no amount of planning can prepare for. This is way beyond the capacity of any of the best rescue forces in the world.
 
jayh said:
That's why it bugs me that so many armchair experts are complaining about Japanese readiness and rescue efforts. There is just so much destruction of different types that no amount of planning can prepare for. This is way beyond the capacity of any of the best rescue forces in the world.
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This ^^^

We're talking about a seismic event which moved the entire freakin' planet by 4 inches on its axis!!!

I think some people expect miracles from technology, as if it's magic :rolleyes:

Well, one good thing that will come out of this is that we'll learn how to better engineer safety systems for nuclear plants.
 
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