Japan Earthquake | Page 1102
If that doesn't work, here's a PDF of it: markfm.dynalias.orgby Markfm 5/11/2011 4:40:25 PM
@dean you can either add individuals and it emails them or make it shared public on the web and then it gives you a web address you can cut and paste here so people know where to find it online.by Nancy 5/11/2011 4:40:40 PM- I have mark's PDF working now.by Nancy 5/11/2011 4:45:19 PM
ty markby dean 5/11/2011 4:45:36 PM
@dean Does the emergency BWR steam cooling system have an alternative exhaust set-up? i.e. if back-up generator power is insufficient for operating the normal exhaust system, how is a potentially explosive hydrogen build-up supposedly mitigated when there is a power outage and only emergency back-up power is running?by es 5/11/2011 4:46:47 PM
LOL, sorry....by Ralph Unger 5/11/2011 4:47:46 PM- www.nei.org Hardened exaust vent, still damaged by the huge quake I would think.by Ralph Unger 5/11/2011 4:50:44 PM
- es.. if I understand you correctly ..and, I haven't gotten into the exhaust systems quite yet.. the typical setup I'm used to tho,, there is a main supply to the facility and a main exhaust that goes out the stacks,, redundant fans.. and most likely interlocked into the building radiation protection system to isolate the building on raising contamination levels..by dean 5/11/2011 4:50:53 PM
Morning all! #4 just started spewing.by LM 5/11/2011 4:51:53 PM- "Vent System: Downcomer/vent header stiffeners, Downcomer lateral bracing
Downcomer longitudinal bracing, Vent header deflector, Vent line drain reinforcement,
Torus-to-drywell vacuum breakers, and Vacuum breaker header support "by Ralph Unger 5/11/2011 4:51:55 PM - I have seen a presentation which showed steam being vented out the middle stack presumably on #3 or 2,,, prior to the tsunami hitting so .. there must have been some of the system left after the EQ.. .by dean 5/11/2011 4:52:33 PM
- "Hardened Vent
In the 1980s, the NRC staff reviewed the potential for accidents more severe than those the
plants were licensed and designed to mitigate. In order to enhance the ability of all containments
to prevent and mitigate the consequences of severe accidents beyond the design basis accidents,
the NRC requested that all plants install a hardened vent. In the event of a core damage accident,
the hardened vent would allow reduction in containment post-accident pressure. Hardened meant
that the vent would transport hydrogen, steam and other accident products and release them
outside the reactor building. This would preclude damage to the reactor building and equipment
from steam and the possible hydrogen explosions. "by Ralph Unger 5/11/2011 4:53:35 PM - Ralph didn't we agree that fukushima didn't do those suggested modification?by dean 5/11/2011 4:54:51 PM
- Actually IIRC they did, the quake was just too large.by Ralph Unger 5/11/2011 4:55:29 PM
"It is our understanding that:
Fukushima Daiichi reactors did have hardened vents." from markey.house.gov (I just looked it up now)by Markfm 5/11/2011 4:56:50 PM- Pics I have seen show a beefed up vent system.by Ralph Unger 5/11/2011 4:57:13 PM
- my assessment will indicate that major facility venting was being performed prior to the tsunami from the plant reaction to EQ and subsequent power loss/EQ damage...by dean 5/11/2011 4:57:16 PM
- @LM-seems to be picking up more now.by momof3 5/11/2011 4:57:32 PM
- you know ralph.. I thought that was what was laying on the groundby dean 5/11/2011 4:57:46 PM
- @Dean OK, thanks. I'm trying to understand the 'closed' emergency steam cooling system really. The report 'Anatomy of a Tragedy: Fukushima Dai-ichi March 2011' states that "Even with emergency diesel generators, the condensate, condensate booster, and feedwater pumps are unavailable due to loss of the normal power supply." (p.11, allthingsnuclear.org ) Is it wrong to assume that if venting is required then at some point a water feed will also be needed to compensate for the loss of steam in the system?by es 5/11/2011 4:58:21 PM
- Huh? It is the piping leading to the huge stacks. A crack would be enough to cause an explosion though.by Ralph Unger 5/11/2011 4:58:56 PM
@Ralph Unger Correct.
There is no NPP in the world that is designed to withstand a 9.0 earthquake. There have only been 4 suck quakes in history and only 2 of them in recorded history if my memory doesn't fail me; the other two are estimates.by Pedro Jesus 5/11/2011 4:58:59 PM- when I looked at the video of the inside of the #3 SFP I could see the stainless liner but little concrete on the outside and in that one spot the steel liner bent out in a bubbleby dean 5/11/2011 4:59:06 PM
- No idea how hardened they really were, of course. (Duct tape wrapped, perhaps)by Markfm 5/11/2011 4:59:39 PM
- Ductwork like you may have in your house vs piping made of steel.by Ralph Unger 5/11/2011 5:00:22 PM
- (suck=such)by Pedro Jesus 5/11/2011 5:00:30 PM
- es. that's correct but in the case of fukushima.. no feedwater system of the magnitude they needed was availble and then reactor vessel level plummeted
by dean 5/11/2011 5:00:43 PM - They did do the mod.by Ralph Unger 5/11/2011 5:00:48 PM
- @dean Thanks. I realise things didn't quite go to plan at Fukushima!by es 5/11/2011 5:01:29 PM
- @Dean, I found 3 documents related to the emergency generators. I need to ask Elaine if she still has the link to one that has gone AWOL on my records. Here are the 3 I found in case they have anything useful:
www.houseoffoust.com
www.houseoffoust.com
www.houseoffoust.comby Nancy 5/11/2011 5:01:44 PM - TY NANCY ..by dean 5/11/2011 5:02:14 PM
- @momof3 Looks like SFP in 4. 3 is still chugging too...although I don't think it's from SFP in that one.by LM 5/11/2011 5:02:42 PM
- nancy good ones..by dean 5/11/2011 5:02:57 PM
- #4 is cooking steadily, 3 looks to have tapered back on blowing out steam.by Nancy 5/11/2011 5:03:09 PM
- Are they flooding the plant to reduce the hydrodynamic load? I wonder... "The hydrodynamic loads are defined in Plant Unique Load Definition Reports and each Mark I
containment was evaluated against its own report. As a result of this effort, Mark I plants
modified their piping and/or pipe supports inside containment to reduce the loads an SRV
discharge would impose on the torus and to withstand post-LOCA loads on SRV discharge
piping. These modifications included pipe supports, discharge line vacuum breakers, “rams
head” discharge pipe fittings and T-quenchers. The modifications provide additional margin to
ensure that SRV actuation will not damage the wetwell pressure boundary, any of the wetwell
internal components or piping, and also ensure that the SRV piping will remain functional during
postulated transients and accidents."by Ralph Unger 5/11/2011 5:04:21 PM - @Nancy@all-I haven't followed the cams all that much (popped in here and there) but is that a lot more than 4 has been churning out overall? Seems like a good bit coming out. Or has it churned out that amount before periodically?by momof3 5/11/2011 5:05:08 PM
QuakeAlert
DATE : 05/11/2011 18:47:26
TIME : 19 minutes ago
REG. : Spain
MAG. : 5.3
DEP. : 1.0 km
ID : 110218
quakes.globalincidentmap.comby Edano 5/11/2011 5:06:50 PM- hi Edanoby dean 5/11/2011 5:07:03 PM
- Ralph.. I think that they reached the point of just filling to level over the fuel to speed up the cooldown overall in the RPV.. the water in the containment next to the vessel would act as a huge heat sink..by dean 5/11/2011 5:07:57 PM
- @dean hi, eq in Cartagena, hope there is no npp aroundby Edano 5/11/2011 5:08:10 PM
- If water was circulating, otherwise it just relieves strain on the reactor and torus.by Ralph Unger 5/11/2011 5:09:03 PM
- @all.. when I get my report completed it will try to explain first 2 hours in the plant.. what should happen normally then with EQ along with loss of off site power then station black out. I am teaming with nancy in collecting the information to supportby dean 5/11/2011 5:09:14 PM
- By floating it...by Ralph Unger 5/11/2011 5:09:22 PM
- yeh Edano..by dean 5/11/2011 5:09:39 PM
- @dean Do you know whether non-Fukushima BWR NPPs normally have back-up feedwater systems available of the magnitude required for a power blackout?by es 5/11/2011 5:09:41 PM
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