Japan Earthquake

Japan Earthquake | Page 2831

@Peter They completely disabled this feature by welding. TEPCO avoids and ignores NISA routinely. Why did they comply on this easily but not do 2?
by lillymunster 1/1/2012 3:43:01 PM

they say the panels were welded after they blew out at the other tepco nuke during 2007 earthquake. nisa did not want the buildings look damaged in the future. maybe they completely missed the sense of the panels. instead, now they drill holes in the roof. :)
by Edano 1/1/2012 3:45:34 PM

complete info on tonite's quake with seismic data from cities and prefectures: www.jma.go.jp
by Edano 1/1/2012 3:48:22 PM

@Peter, the earth shakes, the cracks, leaks, and holes in the buildings steam away. Sadly, nothing new for the New Year. Your article
by toad 1/1/2012 3:52:24 PM

@Edano , that was the quake at Kashiwasaki Kariwa, was not it? I don't think that the panels could have blown in that incident. They must have shook lose. In any case, this seems such a stupidity.
by Peter 1/1/2012 3:53:49 PM

@Peter yes, i could not write that name, but that's what i meant. :)
by Edano 1/1/2012 3:54:24 PM

...functional blowout panels could have saved Unit 4's building!
by Peter 1/1/2012 3:55:22 PM

Tepco and the Toad was very interesting. You might like this non-tech display of some of the same principles. www.youtube.com
by toad 1/1/2012 3:55:25 PM

@toad did you see something on the cameras at Fukushmia after the quake?
by lillymunster 1/1/2012 3:57:34 PM

the shindo scale is location specific. it does not make sense to say there was a 4 shindo without giving the location. the magnitude is an absolute value, it descibes the power of the quake, while shindo describes the felt tremor at a given location. so we had a 7.0 magnitude quake which was felt up to shindo 4 in some locations.
by Edano 1/1/2012 3:57:56 PM

Does anyone have thoughts on why the quake was over such a wide area?
by lillymunster 1/1/2012 3:59:21 PM

@lillymunster i thought about it. it must have released the stress on the tectonic plate that carries japan. the plate moved and dropped a bit. it was bended before.
by Edano 1/1/2012 4:00:52 PM

@toad, hey this so cool. Exactly what my professor explained! It seems, the little beast bit the guy in the end. You can train it not to. As to the nuclear village, looking through the commentaries lilly posted, I felt we are all on the same track. The people of Japan must act now, if they want a future for their children.
by Peter 1/1/2012 4:02:03 PM

this could be a prequake of the big one that they expect in the region south of tokyo, where 3 plates meet.
by Edano 1/1/2012 4:02:03 PM

that's why kan shut down hamaoka.
by Edano 1/1/2012 4:02:34 PM

i am sure the islands are stll bended, waitin for the big release
by Edano 1/1/2012 4:04:42 PM

resosol.org
this was 2007 at Kashiwasaki Kariwa resosol.org
by Edano via Resosol.org 1/1/2012 4:08:22 PM

Connecticut Coalition Against the Millstone Nuclear Power Reactor www.mothballmillstone.org
by Edano 1/1/2012 4:10:28 PM

Tepco had a nice transformer fire going for days!
by Peter 1/1/2012 4:11:12 PM

@Peter cnic.jp
by Edano via Cnic.jp 1/1/2012 4:11:52 PM

cnic.jp
Kashiwazaki-Kariwa Earthquake
Japan's Nuclear Safety Shaken to the Roots
by Edano 1/1/2012 4:12:50 PM

by Edano via Cnic.jp 1/1/2012 4:13:12 PM

looks like a carpet :)
by Edano 1/1/2012 4:13:43 PM

EX SKF did an update. He found the NISA report but it is in Japanese

The blowout panel was dislocated by the earthquake when the metal hinge that was holding the panel was bent by the quake. The negative pressure necessary to contain radioactive materials from escaping couldn't be maintained because of that, and Reactor 3 of Kashiwazaki-Kariwa was shut down. A cold shutdown was achieved within 13 hours.

ex-skf.blogspot.com
by lillymunster 1/1/2012 4:13:44 PM

@lillymunster yes, that's what i thought. it fell down due to the quake, not due to pressure.
by Edano 1/1/2012 4:15:08 PM

As to the Shindo scale, I believe the agency uses automated measuring stations today that record peak ground acceleration and peg it to the scale. As edano points out, the magnitude can vary regionally quite a bit.
by Peter 1/1/2012 4:15:51 PM

@lillymunster , that explains it. As to the KK incident, the ground motion was very much above design basis there and yet tepco managed to shut all reactors down. That experience emboldened them to claim that earthquake damage could not have played a significant role at Fukushima, blaming it all on the tsunami.
by Peter 1/1/2012 4:19:08 PM

The ground motion at KK was greater than expected, because a part of the site sits on top of a small slab of very hard rock. When seismic waves enter the slab, their wave lengths are compressed, increasing their amplitude. Therefore, the reactor buildings were shook harder than the magnitude of the quake led to believe. Interesting effect, they should thought about before they built seven reactors at that location.
by Peter 1/1/2012 4:24:37 PM

The only reason I can see TEPCO complied with this request was it was quick easy and cheap to appease NISA. But nobody successfully raised the question about defeating the purpose of this safety system. I think this goes back to the risk and decision processes issue.
by lillymunster 1/1/2012 4:25:27 PM

@lillymunster a blow out panel is indeed a very low tech "instrument" to prevent overpressure. valves should be able to do it better without dropping down on a quake.
by Edano 1/1/2012 4:35:34 PM

stone age technology.
by Edano 1/1/2012 4:36:58 PM

Reading back through EX-SKF's report, workers tried to open unit 2's blow out panel and couldn't because it was welded shut. This appeared to be before the explosions began. So why the panel fell out when 3 exploded is unusual. The only thing I can think of it the top of building 2 bowed so much with the blast that it broke the welds and released the latches or the workers opened the latches on their attempt so all that was needed was to break the welds.
by lillymunster 1/1/2012 4:37:24 PM

@Edano hmm. Those blow out panels were likely original to the design. The vent system was put in place later, in the 1980's. Maybe they felt the blow out panels were redundant?
by lillymunster 1/1/2012 4:38:10 PM

This blow out panel might merit a letter to the NRC asking them what the status of these panels is on US reactors.
by lillymunster 1/1/2012 4:46:54 PM

@Peter, moving finger- horizontal worm, it's all good. Reading through some of the Perrow gives me pause to wonder, not for the first time in these past 9 months, whether we or the Japanese can overcome our fear and denial to change "risk assessment" to something that includes the preservation of the environment and human life over profit and power. Still sitting in the giant atomic petri dish with no end in sight to an argument over whether or not radiation is harmful to human health is mind-boggling. The questions about the neurological impact of low-level radiation remain unclear...restart North Anna, restart Davis-Besse and this www.telegraph.co.uk Oh well, Happy New Year. Yes, Lm the quake was visible and the se corner of 2 was later steaming.
by toad 1/1/2012 4:47:12 PM

@lillymunster the vent is for the internal pressure of the reactors, not for the building (at least i think so). i don't think they had any countermeasure against pressure in the building, besides the welded panel. a fool's play.
by Edano 1/1/2012 4:48:02 PM

but maybe opening the doors would have helped...
by Edano 1/1/2012 4:50:04 PM

@Edano do you remember something about venting hydrogen into the refueling floor? IIRC there was something about an old system and it being partially intentional? Or it leaked via the old system?

So maybe the building air handling goes to the refueling deck and would benefit from the blow out panel? But the vent is the torus direct vent?
by lillymunster 1/1/2012 4:52:09 PM

@toad I think the risk to people needs to be admitted they do not fully know. Until they fully know the risk to people's health they must provide for at least children to be moved away from the contaminated areas and be serious about the food supply. People will argue about ICRP standards forever, it solves nothing while people are stuck in areas they should not be in.
by lillymunster 1/1/2012 4:54:50 PM

@lillymunster peter might know better, but i think the 1980s upgrade was only for the inner containments. "Wallmann-Ventil" it is called in german.
by Edano 1/1/2012 4:55:14 PM

The workers associate the blow out panels and the hydrogen explosions. They could have provided a way to lower the hydrogen in the building and prevented that type of explosion. That would still do nothing to relieve the reactor pressure. So at unit 3, if the first stage of the explosion was hydrogen in the building, the 2nd stage of the blast was possibly the reactor pressure.
by lillymunster 1/1/2012 4:57:51 PM

i thought the hydrogen in the building stemmed from the spent fuel pools. if not, there must have been a containment leak.
by Edano 1/1/2012 4:58:24 PM

... before the explosions.
by Edano 1/1/2012 4:58:46 PM

The building air handling system does go out into the vent stack by other pipes, it goes through the filter system? I can't remember what they call it. Need to go look at our vent diagrams. I think we have them in our library
by lillymunster 1/1/2012 5:00:34 PM