@Edano If you look at the green door next to it, it would be as high as the door. :-)
by lillymunster 9/19/2011 12:22:14 PM
i don't know if there is a possibility to directly cool the torus. if not, then they have another problem.
by Edano 9/19/2011 12:26:34 PM
they are melting away ..... if i can make it there, i'll make it anywhere .....
by Edano 9/19/2011 12:32:22 PM
There is some way to fill the torus with water to top off the partial water that is supposed to be there but it may be broken. Never heard of any attempt to use it.
by lillymunster 9/19/2011 12:32:25 PM
@Puc the one in the torus?
by lillymunster 9/19/2011 12:32:48 PM
@Puc Not sure if there are multiple sumps in the chamber or not. The elevation drawing isn't heavily detailed. The plants have to have sump pumps to keep water out of the buildings as the water table is high. So when they lost AC power they lost the ability to keep water out of basements, then the watering overflow made that kind of minor.
by lillymunster 9/19/2011 12:46:10 PM
good morning to every one
by dean 9/19/2011 12:46:18 PM
@dean Hi Dean!
by lillymunster 9/19/2011 12:46:49 PM
@ lilly .. good seeing you .. I have so much to catch up on
by dean 9/19/2011 12:47:05 PM
@dean I put together a rough outline and illustration on the corium based on Chernobyl corium. Let me know what you think. I didn't think you were around still when I got it done over the weekend.
www.houseoffoust.comby lillymunster 9/19/2011 12:48:07 PM
good morning Peter,, very nice seeing you
by dean 9/19/2011 12:48:37 PM
@and lilly .. I had a heck of a weekend but am here and ready for action
by dean 9/19/2011 12:49:21 PM
true @ Peter, they use the suppression chamber water for a heat sink with delta temperature expelled to the ocean cooling water (probably treated ocean water), which is another reason no auxilliary water was available for cooling after the tsunami
by dean 9/19/2011 12:51:31 PM
Has anyone seen lateral measurements for the corium flow at Chernobyl. The two diagrams I found don't seem to totally match. One shows extensive lateral movement but no measurements laterally. The other shows the total building at 69 meters but most of the corium staying in the region under the core area.
by lillymunster 9/19/2011 12:53:54 PM
well done @ Lilly, you've captured all the right info out of that link to begin assessment of paths of least resistance for the corium to leak or burn out
by dean 9/19/2011 12:56:43 PM
I haven't search for those kinds of details @ lilly but I could poke around. perhaps it could be scaled to some other reference measurement
by dean 9/19/2011 12:58:06 PM
@Ian that is a useful reference, I might be able to extrapolate some measurements with that and the chernobyl elevation drawing that shows building size.
by lillymunster 9/19/2011 1:00:52 PM
@All - the video Ian posted talks about sand stored around the reactor as being pulled down with the core and melting with it. Would sand or the graphite moderator do anything positive or negative to the corium flow? Saturday we came to the assumption the graphite would just burn.
by lillymunster 9/19/2011 1:02:10 PM
en.wikipedia.org @ lilly this shows viscosity example, Ian is right about the effect the silica sand had. it changed the state of where the corium would become solidified instead of remaining molten.
by dean 9/19/2011 1:10:10 PM
@Ian @Dean - so we would see more movement potentially at Fuku unless other factors at Fuku slowed it down?
by lillymunster 9/19/2011 1:10:59 PM
At CHERNOBYL.....The corium was formed in three phases.
The first phase lasted only several seconds, with temperatures locally exceeding 2600 °C, when a zirconium-uranium-oxide melt formed from no more than 30% of the core. Examination of a hot particle shown a formation of Zr-U-O and UOx-Zr phases; the 0.9 mm thick niobium zircaloy cladding formed successive layers of UOx, UOx+Zr, Zr-U-O, metallic Zr(O), and zirconium dioxide. These phases were found individually or together in the hot particles dispersed from the core.[18]
The second stage, lasting for six days, was characterized by interaction of the melt with silicate structural materials – sand, concrete, serpentinite. The molten mixture is enriched with silica and silicates.
The third stage followed, when lamination of the fuel occurred and the melt broke through into the floors below and solidified there.
by dean 9/19/2011 1:13:53 PM
@dean would corium become more viscous when shaken?
by lillymunster 9/19/2011 1:16:36 PM
en.wikipedia.org @ lilly, this discusses some specifics about corium, looks like it gets complicated, corium consisting of so many parts with varying melting points and viscosity
by dean 9/19/2011 1:16:48 PM
@ lilly, my feeling is that if the corium core temperature was still high and close to the melt temperature and had a crust formed on the outside which would block oxygen from getting through, shaking could open fissures or gaps in the corium and result in further increases in temperature
by dean 9/19/2011 1:18:29 PM
The corium undergoes degradation. The Elephant's Foot, hard and strong shortly after its formation, is now cracked enough that a glue-treated wad easily separated its top 1–2 centimeter layer. The structure's shape itself is changed as the material slides down and settles. The corium temperature is now just slightly different from ambient, the material is therefore subject to both day-night temperature cycling and weathering by water. The heterogeneous nature of corium and different thermal expansion coefficients of the components causes material deterioration with thermal cycling. Large amounts of residual stresses were introduced during solidification due to the uncontrolled cooling rate. The water, seeping into pores and microcracks and freezing there, the same process that creates potholes on roads, accelerates cracking.
by dean 9/19/2011 1:19:58 PM
@dean Interesting. The video Ian posted talked about concerns of the corium turning to dust or creating dust and also worries of the reactor lid falling creating a massive dust cloud.
by lillymunster 9/19/2011 1:24:29 PM
I believe that fukushima introduced a completely new unkown in extreme accidents at NPP's which is what I call,,, POST CORE MELT SEISMIC ACCIDENTS.... I've sent letters to NRC and DOE strongly suggesting they begin studies to better understand and model this
by dean 9/19/2011 1:25:15 PM
@ lilly ,,, the same exists at FUKUSHIMA and one wonders how robust the TENT they are building over the reactors and good it will be at "containing" such dust and radioactive particles from escaping. Chernobyl seems to be waiting for a considerable accident and it is imperative to get that other container built quickly.
by dean 9/19/2011 1:27:38 PM
@ Lilly I am still totally amazed that they have not core drilled to get some videos of inside those areas in fukushima reactors where corium could exist and set up some sort of tracking. core drill holes outside the plant and lower sensors to detect movement or relocation. grrrrrrrrr
by dean 9/19/2011 1:29:29 PM
@ lilly, after chernobyl I do remember the DOE coming around and wanting to know where everyone's piles of sand were in case of an accident. It was the favored defense if melting occured.
by dean 9/19/2011 1:33:20 PM
@dean It seems to be totally absent and as you have mentioned there are ways to do so. I am surprised there hasn't been more pressure from university programs to do more of that kind of thing.
by lillymunster 9/19/2011 1:35:03 PM
I had hoped we could find something related to tracking or monitoring the corium at fuku
by dean 9/19/2011 1:40:07 PM
@dean TEPCO has been reporting all sorts of things lately, but none that seemed to hint at trying to find out where the fuel is. The only things even remotely like that were air testing above each unit and bore holes drilled to test before they put in the underground walls.
by lillymunster 9/19/2011 1:47:24 PM
I wonder what gunderson would theorize on this
by dean 9/19/2011 1:49:12 PM
2012indyinfo.wordpress.com very interesting article with this comment "We’re in the uncharted territory that we enter for the first time ever since the human race started to use nuclear power."
by dean 9/19/2011 1:52:58 PM
@dean link didnt work
by lillymunster 9/19/2011 1:55:46 PM
@lillymunster Good job with that article.by Pedro Jesus 9/19/2011 12:23:11 PM
distance floor of the suwp pump to earth is about 1,5 mby Puc 9/19/2011 12:32:33 PM
good morning quickly before I must go again. The water in the suppression chamber is normally cooled with the help of the residual heat remover (RHR). At Daiichi the RHR exchanges the heat with the ocean. The tsunami broke them for most units (not sure for 5 and 6, but certain for 1 through 4). There were attempts to fix them. But they did not function in the weeks after the quake/tsunami.by Peter 9/19/2011 12:48:19 PM
@lillymunster, this shows extensive lateral corium flow at Chernobyl : www.youtube.comby Ian 9/19/2011 12:57:56 PM
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