Japan Earthquake

Japan Earthquake | Page 1853

@RBeaner That one «piece» of fuel rod was pretty small and thought to have been ejected from one of the spent fuel pools in one of those violent hydrogen explosions that crippled the units #1, #3 and #4's secondary containment structures.
by Pedro Jesus 7/7/2011 3:01:41 PM

i think there is sufficient evidence for fuel rod dislocation from #3 at least.
by Edano 7/7/2011 3:05:55 PM

@Edano Well fuel element failures occurr from time to time. These are released into the primary coolant and then absorbed by the ion exchangers and filtering system. It is entirely concievable (to me) that the explosions damaged and blew up some of these resin systems, spreading the crap around. To me that is more likely than a fuel rod being ejected from a pool or reactor. There was (US) NRC doc that referenced the fuel particle, I can't find it now though.
by RBeaner 7/7/2011 3:08:17 PM

@Edano there were early claims of fuel or highly radioactive material on the ground past #4. TEPCO seemed to use terms interchangeably but they did at times claim fuel rods or parts of them were out on the ground.
by lillymunster 7/7/2011 3:08:23 PM

@RBeaner Some of the documentation on MOX says the fuel can be vaporized in a melt down. This might explain some of the really high rad level debris.
by lillymunster 7/7/2011 3:09:18 PM

a fuel rod failure is not an incident that has to be reported ?
by Edano 7/7/2011 3:11:35 PM

@all Just my 2 cents...I don't have the link to the 3 SFP footage but any layman looking at it could easily infer fuel rod displacement.
by LM 7/7/2011 3:11:54 PM

@lillymunster IIRC, MOX will add 30% to the rad levels of a disaster. So #3 has the potential to be a little worse than 1 or 2, but isn't #3 rated for higher power, larger core, and thus expected to have higher rad levels and consequences even without mox?
by RBeaner 7/7/2011 3:12:37 PM

@LM There is a big difference between shoving fuel around a bit versus ejecting it from the pool or reactor. I agree that just the weight of material that fell into the pool, would cause some movement (lateral) of the stored fuel.
by RBeaner 7/7/2011 3:14:49 PM

@LM There is displacement of fuel rods but not substantial as in fuel rods scattered around the plant outside the SFP. I think that's what RBeaner meant by substantial fuel rod displacement. There is no evidence of it.
by Pedro Jesus 7/7/2011 3:15:29 PM

@Pedro Jesus they caterpillared the evidence deep into the soil.
by Edano 7/7/2011 3:16:49 PM

@Pedro Jesus Maybe I should have used the words "fuel Rod Relocation" instead of displacement. I agree that the assemblies have been jarred and shifted slightly.
by RBeaner 7/7/2011 3:17:04 PM

@RBeaner 3 & 4 are identical 2-5 are all 784mw #1 is 460mw. From most of what I have read so far I think the mox played a critical role in the violence of the explosion possibly due to how fast and how easily it breaks down. There are also concerns the cladding and fuel pellets in #3 were defective as the ones rejected at another plant in 1999. So there could have been some massive fast failure in 3. I am still trying to determine 100% that the 28 assemblies from Kashiwazaki did not get moved to Fuku after they loaded the existing mox.
by lillymunster 7/7/2011 3:17:24 PM

@Edano There is no evidence of that either. They have been piling up the radioactive debris around the plant so they can move the machinery around. There is no evidence that they did it to hide something. It's just an assumption. We're talking about evidence.
by Pedro Jesus 7/7/2011 3:19:47 PM

@edano You took the words out of my mouth. Thank you!
by LM 7/7/2011 3:19:53 PM

What information could help sort some of this out?
by lillymunster 7/7/2011 3:21:41 PM

@RBeaner Displaced slightly?! Did you see the explosion and the footage of the pool? Wow. I wish I had your glasses. I really need a pair!
by LM 7/7/2011 3:22:04 PM

@Edano I don't know the formal reporting requirements, but "Reactor plants are designed with the expectation of some fuel element failures during the life of a core; so long as the failure is not serious the plant will continue in operation." atomicpowerreview.blogspot.com This issue is not routine, but it happens. This is not a big deal for the plant, the filtering systems just have to work a little harder. The only effect is on water chemistry, and is easily compensated for. This does not release anything to the enviornment whatsoever.
by RBeaner 7/7/2011 3:23:34 PM

@lillymunster, is the MOX dox saying it can be vaporized in a meltdown on the simplyinfo?

I'm getting increasing skeptical that spent fuel was ejected from the pool, and so looking for some explanation for fuel elements found around the plant. If MOX can be vaporized, I think I have a simpler fact-fitting explanatory model.
by Ian 7/7/2011 3:25:00 PM

Doesn't look like a lot of cooling going on with those reactors. Over the last two days #2 has had an improvement in one reading, but overall things are pretty flat or rising slightly, everything over 100C.
by Markfm 7/7/2011 3:25:50 PM

talking of evidence ... i have seen no evidence up to now that all the fuel rods are sound and completely or in parts in their pools.
by Edano 7/7/2011 3:26:07 PM

NHK stories carried in today’s JAIF Earthquake Report: (Fukushima NPP Site) ●Wastewater filters not working to capacity ●TEPCO says reactor cooling on target at 80 percent (Other news) ●Utility admits to dishonest e-mails on restart ●Japan's nuclear crisis affects farm exports ●Tokyo parents demand safe school lunch ●Govt to conduct stress tests at all nuclear plants ●Kan orders new rules to restart nuclear reactors ●Microbes used to remove cesium in water and soil ●Plaintiffs demand decommission of Hamaoka reactors ●Gov't plans additional nuclear safety tests ●Background on nuclear stress tests ●Radioactive strontium to be closely monitored
by Markfm 7/7/2011 3:28:45 PM

@LM I ahve seen no evidence that an explosion ocurred INSIDE any pool. The rods in the pools were several feet (probably several meters) underwater at the time of the explosions. The explosions above the pool would have relatively small effect underwater (water does not compress), therefore I assume any damage to fuel in the pool came from heavy debris (cranes and other steal) raining down from above. Yes #3 SFP is a mess, but I have no reason to believe (or evidence to show) that fuel leapt out of the pool and beached itself on the deck of the refueling floor.
by RBeaner 7/7/2011 3:30:30 PM

@Markfm are they still holding back on watering or is there maybe another reason for the rising temps?
by lillymunster 7/7/2011 3:31:48 PM

@RBeaner Good point.
by Pedro Jesus 7/7/2011 3:34:11 PM

@Ian when you say elements I am assuming you mean just that isotopes or radiation being found, not elements as in a "fuel element" being an object. I don't have a write up on the MOX properties yet, still working on that and Smoss is researching some other angles of the MOX situation there.
BTW, Smoss has a short paper out for peer review related to MOX and TEPCO wp.me feedback can be posted here.
by lillymunster 7/7/2011 3:34:32 PM

@RBeaner None of us know what truly happened. You talk of speculation, but yours is as well. The explosion at 3 was different than the others and there IS proof of that...just look at the videos. Where are all the fuel rods in the SFP now? They certainly are not all visible..we can at least agree on that. I won't argue with you. Just admit that your viewpoint is also speculation.
by LM 7/7/2011 3:34:37 PM

@LM exactly
by Edano 7/7/2011 3:35:20 PM

This study appears to indicate that some fission elements including plutonium can be vaporized from MOX www.jstage.jst.go.jp
by Ian 7/7/2011 3:35:31 PM

Water flow is still low. I don't know if the water treatment is perhaps sufficiently under-performing that they're still losing ground, or what other reason there could be. There aren't major rises, but I'd hardly call #3 readings of 123 - 162C, #2 116 - 144C, #1 102 - 117C "good".
by Markfm 7/7/2011 3:35:33 PM

I would love to see some more/better images of 3's sfp.
by lillymunster 7/7/2011 3:35:41 PM

@Markfm 99.7 is boiling point. Yea those levels are hardly good.
by lillymunster 7/7/2011 3:37:34 PM

back.. i want to shed some light on a few things concerning comments that have been made... @ RBeaner there have been times in my career where a fuel element develops what's call a leaker.. ie; a minute flaw in the cladding and it begins to put isotopes out into the primary water and that is cleaned up in the plant purification system, if it gets too bad the reactor shuts down.... on the other hand.. IF you look at the SL-1 you will see twisted debris all over and visual fuel element material.. likewise when they brought the core debris from TMI-2 to the area where i worked there were similar case damage and that of the inside of the TMI core.... now, THOSE rods we are seeing..need to be scrutinized for us to determine if they are fuel rods... as for myself.. with all the evidence presented about the nature and extent of the explosions I will go on record to say that this debris can be fuel rods that have been deformed, separated, exploded etc and whose projet
cile path is unknown.
by dean 7/7/2011 3:38:01 PM

@lillymunster That might sort the issue out (re: SFP).
by Pedro Jesus 7/7/2011 3:38:13 PM

@lillymunster, right, not the objects, just the atoms. The study I just posted is important in this. I'm not sure is 'vaporized' is the right word wrt plutonium release, but I think they're saying some Pu is liberated into the air. It says 100% of cesium is, which is consistent with finding so much of it. I really think I'm ready to drop the SFP fuel-liberation theory
.
by Ian 7/7/2011 3:39:30 PM

@Edano Good paper from IAEA on Fuel element failure.. of note "The current fuel rod failure rate varies in different countries with an
average around 10–5, except in Japan where reactors have operated practically free of defects for more than ten years" Japan seems to be exceptional... www.google.com
by RBeaner 7/7/2011 3:40:19 PM

@dean Correct me if I am wrong, but a "leaker" is a term for a minor fuel element failure.
by RBeaner 7/7/2011 3:42:20 PM

@RBeaner or Japan chooses to report in a manner that looks like no fuel failures. The inspections on the MOX that went into #3 showed it already had some minor cladding issues yet they installed it. From what I understand the level or degradation would have gotten rods rejected in other situations.
by lillymunster 7/7/2011 3:42:38 PM

@Ian I wouldn't completely drop it. Chances are both theories could be right. Some small chunks of spent fuel rods might have been ejected by the explosion and some will have radiated vaporised radioactive debris that sets on the soil around the plant. 1.5Km outside the plant is not that big a distance considering Fukushima-Daiichi is about 1.6Km wide.
by Pedro Jesus 7/7/2011 3:42:54 PM

Nitrogen injection could be delayed at Fukushima www3.nhk.or.jp "on Wednesday examined the No.3 reactor...failed to confirm the situation because the robot couldn't reach the necessary part of the reactor"
by Markfm 7/7/2011 3:42:57 PM

@lillymunster like I said, Japan seems to be exceptional in this regard.
by RBeaner 7/7/2011 3:43:49 PM

leaker is in the report you posted RBeaner.. we should be breaking things down if we are going to start talking of failures, burns, vaporized etc. so we are all on the same page.... a leaker is the first sign of a potential failure of the cladding and, ,can lead to a more serious breach of the cladding, over temperature and subsequent fuel interaction like the fuel liquidus and melt...
by dean 7/7/2011 3:44:10 PM

The flash of fire over SFP3 could be a result of ejecting ignited gas from the reactor. Notice that reactor-well steam billowed out along both due north and south trajectories. The south trajectory could account for the flash over the pool, the pool being inconsequential in this model.
by Ian 7/7/2011 3:44:30 PM

also.. reports of Cs, Iodines, noble gasses etc from nuclear accidents are usually done on specific analyses which have several assumptions which are different that the fukushima severe accidents.. they use these estimates in release calculations etc.
by dean 7/7/2011 3:46:02 PM

the article above on the ask.com.. was really a different read for me.. and made me think of some things differently .. but still needs exploration and research..
by dean 7/7/2011 3:46:54 PM