Published: July 14th, 2012 at 10:27 am ET
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Title: Panel: Unable to get details on radiation release
Source: NHK WORLD English
Date: Jul. 13, 2012
NHK has learned that a government panel of experts will say it has been unable to specify exactly how the radioactive release occurred at a reactor of the crippled Fukushima Daiichi nuclear power plant.
[...]
Professor Koji Okamoto at the University of Tokyo Graduate School says [...] the investigation should be continued with help from experts from abroad.
Massive radioactive release from No. 2 occurred one day after fuel melted through containment vessel?
On March 15th, 4 days after the breakdown of the Fukushima Daiichi plant, its No. 2 reactor appeared to release the largest amount of radioactive substances since the start of the disaster.
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The report will say pressure in the suppression chamber of the No. 2 reactor was falling gradually between 1:30 pm to 6:00 pm on March 14th.
It will say this suggests that the suppression chamber collapsed at the time.
[Tepco] has insisted that the suppression chamber was destroyed during the morning hours of March 15th, when pressure was falling rapidly, instead of the previous day.
The panel will take issue with TEPCO’s view, saying their analysis probably does not reflect what actually happened.
[...]
“The containment is divided into the drywell containing the reactor vessel and the wetwell (torus) containing the suppression pool” -NRC
Published: July 14th, 2012 at 10:27 am ET
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They have recordings of all the melt downs and explosions, could they not analysis these, like a black box in areoplane and reverse engineer, maybe their is some answers their.
Anybody in that field of occupation please try, you have the equipment.
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I'm not sure what actual recordings were taking place since all the gauges were offline given the prolonged power outage, and many still are. That is why all the experts are guessing. Very little was able to be measured.
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But then they would have to tell the truth..
uh oh… trouble..
better cover up, deny, minimize, claim loss of all equipment, power failures, no measurements at all.
yup, sounds like a good plan to make the nuclear monopoly look good. They claim that they can 'do' one of these accidents every 20 years and prosper.
What do you think?
Fukushima 5 Minute Summary Of Events 2011 to 2012; via A Green Road
http://agreenroad.blogspot.com/2012/06/fukushima-5-minute-summary-of-events.html
Total Fukushima Radiation Released Into Ocean, Air, Groundwater, Storage Tanks; via A Green Road Blog http://agreenroad.blogspot.com/2012/02/total-fukushima-radiation-released-into.html
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TEPCO did report that the #2 torus had blown. I don't think it matters too much whether it blew on the 14th or the 15th. "Collapse" is a different condition than "explosion" breaching the torus, but only when considering where the core went, how it got out of the facility, and whether or not the structure can hold water (in the case of #2, it can't).
This condition is different from conditions at reactors 1 & 3, where it would appear the corium melted straight down through the dry-well as opposed to exiting through conduits to the toruses. The #2 by-pass through the torus would tend to send the corium 'sideways' instead of straight down, more likely to follow paths of least resistance (fractures in the rock, veins of softer material, led by the escaping water) while seeking its gravitational level. Which, in this case, is the cliff and exit to the lagoon.
So while the coriums of 1 & 3 may be headed mostly straight down, the corium from #2 is more likely headed for the cliff. And that explains boiling water 'geysers' and steam vents from the ground around the unit and in the direction of the sea.
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for which reason the pellets rolled off the reactor core, into the torus?
was it a physical design of the core, or a random event ?
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Now, that's scary.
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I always enjoy your thoughtful analysis, JoyB. I'm not yet persuaded of a significant vertical/sideways difference though. Once the corium leaves the R2 torus, wouldn't it go down in much the same way as it does from R1 and R3?… sideways to get into the torus, but generally (least resistance) down once it leaves?
Am I overlooking something?
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Whether the Torus blew up or not has little to do with where the corium went. There is no pathway for large amounts of fuel to exit the pressure vessel and go through the Torus. The dose rates in the Torus are from small flakes and particles of fuel that were distributed wherever the water from the core went. Any emergencies water systems that were used after the fuel was overheated sent disintegrated fuel particles through those systems also.
Most of the fuel went through the bottom of the reactor pressure vessel, escaped through the penetrations at the bottom of the vessel, and ended up in the drywell basement. When more fuel collected at the bottom of the pressure vessel and temperatures exceeded the melting point of stainless steel the corium broke through the bottom of the vessel. This glob of melted fuel dripped and flowed into the drywell basement. As water broke through the vessel along with the fuel it flooded the basement and possibly the lower ground level of the drywell, where it dispersed the corium at least somewhat.
What happened to the corium sitting in the drywell basement is a question that gets lots of conjecture but is a difficult question to answer. Some most likely started to melt through the concrete. But no one will ever know how much fuel got deposited where and how deep it went in the end.
But only small amounts of fuel particles, which were carried by the water flow went into the Torus, and this small amount is still extremely deadly.
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