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Thread: meltdown vid
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03-12-2011 10:24 AM #1Registered Member
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03-12-2011 11:11 AM #2
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03-12-2011 12:07 PM #3
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03-12-2011 01:45 PM #4Registered Member
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Re: meltdown vid
At 3:40pm local time in Japan's Fukushima Prefecture, an explosion shook the Fukushima Daiichi nuclear plant. Four people were reported injured from the initial blast, but broader concerns over increased radiation leakage have lead officials to double the evacuation zone around the plant from 6 to 12 miles. What the ultimate fallout will be is anyone's guess.
The Daiichi plant is one of the two that experienced cooling failure early after yesterday's devastating quake, and was teetering on the brink of a meltdown just hours ago. According to Tokyo Electric Power Company, the explosion happened "near" but not in the Unit 1 reactor. Radiation levels had reached 1,000 times above normal in a reactor control room at the plant, and more troublingly levels had reached 8x normal near the main gate.
The important thing, though, is that it appears that the explosion—likely caused by a hydrogen build-up—only affected the wall around the reactor and not steel container housing the reactor itself. The important thing now is that cooling operations continue unhampered. If the cooling systems are inoperative for several hours, the reactor's water will boil away and the fuel will begin to melt. When that happens, the situation escalates from "manageable" to "Three Mile Island." And while there are indications that radiation levels have in fact declined since the explosion, Daiichi is still currently walking that line very tightly.
The International Atomic Energy Agency is providing real-time updates on Daiichi on its Facebook page. We will as well as the situation warrants. [Russia Today, NY Times]
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03-12-2011 01:59 PM #5
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03-12-2011 02:06 PM #6
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03-12-2011 03:35 PM #7Registered Member
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They use the american reactor design, not russian
That building is secondary containment, not primary. The reactor is hardened, usually sitting below ground level, and designed to be self sufficient. It is intriguing that the reactor safeties have not sufficiently stopped the fission process. In times of extreme emergency (like when the secondary containment system is destroyed) the reactors control rods are supposed to be completely lowered into place and the reactor chamber is flooded with borated water to further contain the neutron flux and slow the fission process allowing the reactor to cool. I read that they are flooding the reactor with seawater, which also works, on a less efficient basis, to slow fission, and act as a huge heat sink to further cool the reactor chamber.
Rowley, do you do nuke work, or are you in a different division?
My cousins are GE nuclear, one a refit and refueling engineer, and the other a refueling technician. They were saying that this system should be ok so long as they keep it cool. Although secondary containment has some greater than background levels of radiation that has now been completely released. Into the ocean that amount of radiation will mean nothing, but if primary containment is breached, then there will be hell to pay. They might need to construct a cooling pool around this damaged reactor and maintain it under sea water indefinitely. They said that if there is any danger to primary containment, expect to see a [Oops!] load of concrete rushed in and used.
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03-12-2011 05:14 PM #8
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03-12-2011 06:51 PM #9
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03-12-2011 07:28 PM #10
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03-12-2011 08:15 PM #11
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03-12-2011 09:24 PM #12
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03-12-2011 10:29 PM #13Registered Member
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Does read like a bad scifi flick, yet
god must be punishing them because they were mean to whales
http://www.latimes.com/news/science/...,3146984.story
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03-12-2011 10:36 PM #14
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03-12-2011 11:05 PM #15
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03-12-2011 11:10 PM #16
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03-12-2011 11:17 PM #17
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03-12-2011 11:59 PM #18Registered Member
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They are saying likely a meltdown in 1 reactor.
Which shouldn't be possible with the failsafe systems that are designed in. Which means that either the failsafe's were fatally damaged in the quake, or that the designs are not as failsafe as we have all been led to believe. Which is potentially bad news for our nuke plants near major quake zones.
Unfortunately this might just be used to stop new nuke plant construction, when the real problem is that all of our nuke plants are very old designs. What we need are new plants, with the new designs. Will probably never happen though.
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03-13-2011 01:52 AM #19Registered Member
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We won't know the story for a while
News has been very contradictory coming out of there. Takes a number of significant F-ups to blow the top off a reactor building.
Grimlok, I've probably worked with your cousins at some point if they've been around for a while. I'm ex-GE. My neighbor in Lakeport literally started up Fuku Unit 1 back in the mid seventies. I have a picture somewhere of me holding up a piece of its core shroud we cut up with water jets back in '01. Lot of fond memories for me from that unit. It was the first unit I worked on in Japan back in 1990.
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03-13-2011 04:11 AM #20
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