Japan Earthquake

Japan Earthquake | Page 895

Hmmm, so now I don't know. Maybe the fire WAS in or near the SFP and TEPCO has stuffed that down the memory hole?
by General Armchair 4/29/2011 3:53:47 PM

@General Armchair Tepco says two fires were both NW corner, but... And they don't say much about the explosion, considering it demolished the about half the bldg.
by marie rich 4/29/2011 3:57:33 PM

@elainekirk If I read this right, what the amendment does is allow one unit to use another units emergency generator for compliance of emergency procedures. You almost need to be a lawer to read this stuff.
by Shadow 4/29/2011 4:06:45 PM

Oh,,,,,,,Good morning all:)
by Shadow 4/29/2011 4:08:16 PM

@Shadow Is that in reference to TEPCO request for amendment of NISA orders at Fukushima Daini?
by General Armchair 4/29/2011 4:08:40 PM

hi!
by marie rich 4/29/2011 4:08:45 PM

(And good morning to you, too!)
by General Armchair 4/29/2011 4:08:54 PM

@General Armchair Yes.
by Shadow 4/29/2011 4:09:13 PM

I was trying to figure that out yesterday too, but couldn't.
by General Armchair 4/29/2011 4:09:38 PM

Apropos of nothing, I wish Cryptome could provide much smaller pics (with links to see the full-size images).
by General Armchair 4/29/2011 4:20:40 PM

(10 minutes later and still waiting for their latest photoset to finish loading grrrrrrrr -- and they're concerned about bandwidth wastage!)
by General Armchair 4/29/2011 4:21:36 PM

@General Armchair @marie rich Teppycams for March 15... smoke starts to rise at 6am, by 7am we have a smaller #4 building, the Cherenkov feature appears gyldengrisgaard.dk
by Bobby1 4/29/2011 4:28:12 PM

I was just reviewing pics of #4 trying to see smoke smudges around NW corner, but cursory looks don't reveal much.

Has it ever been determined what the big curved piece on the #4 roof is (right next to the inward-bowed wall section) was?
by General Armchair 4/29/2011 4:34:46 PM

@Bobby1 looks very interesting- esp. in hindsight
by marie rich 4/29/2011 4:35:06 PM

@Bobby1 By Cherenkov feature you mean the small blueish circle that is seen in most of those pics?
by General Armchair 4/29/2011 4:36:21 PM

back
by dean 4/29/2011 4:37:55 PM

I am wondering if possibly that curved piece is maybe rolled up roof material? A kind of tarpaper? I have no idea what kind of construction methods are used, but do note other crap on (for instance) #3 turbine building roof that looks a lot like something fabric. These can be seen as thermally hotter than the rest of #3 turbine bldg roof in thermal images (but they are darker than the roof so possibly just absorbing more heat?).
by General Armchair 4/29/2011 4:39:02 PM

Given that big curved piece appears AFTER #4 explosion, it's not from #3 and I don't see how anything large and structural could have landed on top of #4 roof from an explosion inside #4, that didn't significantly damage the #4 roof girder structure.
by General Armchair 4/29/2011 4:41:25 PM

@General Armchair Yes, or luminescence or whatever.
by Bobby1 4/29/2011 4:41:29 PM

Um what happened to the last post? Something about the double-stacking?
by General Armchair 4/29/2011 4:45:19 PM

I don't think they're actually using two layers in the SFP. What is being done is re-racking, increasing the density of the rods by spacing them closer together. Supposedly you use mechanisms like boron sheets to keep problems from coming up.
by Markfm 4/29/2011 4:45:26 PM

Thanks for that timeline re #4, @General Armchair, and @Bobby for the teppycam history. I'm still confused about the reporting of the explosion at Unit 4. I'm convinced this explosion wasn't mentioned at the time and am also sure references had still not been inserted into TEPCO's history before at least the 25th March (still looking for info on this). In this NHK recording from March 16th (see specifically from c.1min in) there's no mention of an explosion at 4, nor of any major damage to the building - just reports of a fire which damaged the roof on Tuesday and the 8m hole in the wall they were going make use of to hose water into the SFP. JAPAN: News Updates from NHK in Tokyo, March 16, 01:00am: www.youtube.com
by es 4/29/2011 4:46:38 PM

@mark there is a doc with diagrams I am searching but keep going of at a tangent when I see something new :)
by elainekirk 4/29/2011 4:47:24 PM

@Markfm It does LOOK a little like there might be two layers in the short video released by TEPCO but I'm certainly not capable of saying anything definitive.
by General Armchair 4/29/2011 4:47:36 PM

@All, off to work. Take care
by Shadow 4/29/2011 4:49:10 PM

see you later shadow
by dean 4/29/2011 4:49:42 PM

re-racking, what a poor decision
by dean 4/29/2011 4:53:11 PM

@es Hmm, yeah, 8 square meters would seem to significantly underestimate the size of the hole in #4 wall!
by General Armchair 4/29/2011 4:53:19 PM

www.iaea.org some re-rack information
by dean 4/29/2011 4:54:51 PM

@dean Thanks am reading it now.
by General Armchair 4/29/2011 4:57:02 PM

It is correct to assume that boron gets "used up" in terms of absorbing neutrons?
by General Armchair 4/29/2011 4:59:28 PM

Sorry, meant that as a question: IS IT correct....?
by General Armchair 4/29/2011 4:59:49 PM

I really am opposed to the re-racking because from a safety standpoint just imagine.. it puts racks of fuel elements between the top of the other racks and then reduces the margins of safety in the event of a canal leak.. ie" less water over the re-racked fuel..
by dean 4/29/2011 5:00:02 PM

NRC says Fukushima situation has definitely improved green.blogs.nytimes.com
NRC says San Onofre nuke plant is safe www.mercurynews.com
by Bobby1 4/29/2011 5:00:53 PM

General... at the facility I worked at we had to inspect the fuel racks which were lined with cadmium to ensure their integrity and at had to maintain the cadmium density and also to ensure that we maintained fuel element separation from a critical array .
by dean 4/29/2011 5:01:32 PM

@dean OT but have wondered this -- when refueling do they move ALL assemblies around? I would assume you might want to move assemblies from center of core to outer edges or vice versa -- some way to juggle where you put assemblies of various ages so as to ensure uniform burn up?
by General Armchair 4/29/2011 5:03:45 PM

Bobbb1 that's a bold statement for NRC to say... "definately improved"... my question to them would be this.. ok so you say definately improved.. well last say that the condition just occured where your definately improved state is... how would you rate it on the case of severity... my opinion . fukushima is a dynamic unstable set of facility problems .... clearly to me .. not improved and clearly to me still very potentially lethal
by dean 4/29/2011 5:05:58 PM

@General Armchair As I recall that 8m hole was pointed out to be the rectangular hole in the SW wall visible on the first of the new cryptome pics: cryptome.org At the time I actually thought TEPCO had made the hole to gain better access to the SFP - they were making out it was going to be tricky to get to 4's SFP with the heli-drop, since so much of the roof remained intact, unlike #3.
by es 4/29/2011 5:06:48 PM

From dean's link: "Boron carbide is an extremely stable and inert chemical compound, which does not react with any material, found in spent fuel pools."

Any thoughts as to what it might react to in seawater, etc.? I would assume they would have known or checked on this before dumping in the seawater but there's always the chance that they might have done something they knew was a bad idea in the long run, but in the short run it was more inmportant to keep the fuel cool?
by General Armchair 4/29/2011 5:07:30 PM

General.. from my experience.. fuel useage in cores is a very complex issue,, trying to get the best utilization of fuel burnup, trying to keep the storage of aging fuel segregated such as to provide long term storage in preparation to dry cask store or common pool store or.. be re-used at another time in the core... they typically only move 1/3 or so of the fuel from one operating period to the canal and replace...
by dean 4/29/2011 5:08:58 PM

@es That's one of the pics that didn't fully load for me from latest Cyrptome....grrrr....do you mean the one panel that is gone on the S. side of #4 on either the 2nd or 3rd level (not sure which, but it's the lowest panel gone (and only one gone on that level) on the S. side?
by General Armchair 4/29/2011 5:09:24 PM

@General Armchair Think so. Sounds about right.
by es 4/29/2011 5:10:00 PM

General, I believe there was no choice other than to use seawater and when that decision was made... they knew the consequences of never using the facility again...
by dean 4/29/2011 5:10:16 PM