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Japan's Nukes Following Earthquake

Started by Marvin, Mar 11, 2011, 11:27

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War Eagle

I watched a translated news conference where the spokesman implied that Unit 2's primary containment may have been breached in the most recent explosion. Did anyone hear the same?

PJMcG

Quote from: War Eagle on Mar 14, 2011, 07:43
I watched a translated news conference where the spokesman implied that Unit 2's primary containment may have been breached in the most recent explosion. Did anyone hear the same?



I heard the same thing, but am reluctant to repeat it until confirmed.  If this preliminary report is true, this is the worst news yet.
"By its paw shall you know the lion."

TWillis


Albert

Quote from: remer on Mar 14, 2011, 07:15
Word is that Unit 2 just suffered a hydrogen explosion. No real sources or info yet.

MSNBC reports that an explosion was heard at Unit 2:
http://www.msnbc.msn.com/id/42066534/ns/world_news-asiapacific/

JustinHEMI05

Quote from: JustinHEMI on Mar 14, 2011, 04:19
Another good source;

http://www.jaif.or.jp/english/

And the latest update from there;

http://www.jaif.or.jp/english/news/2011/110314fukushima_event-status-2.pdf

It looks like unit 2 is having some issues. Has the news said anything about it?

Saw that coming earlier.  ::) God help them.

Cycoticpenguin

Who is Robert Alvarez, and why is he allowed to speak in public? -.-


G-reg

Quote from: JustinHEMI on Mar 14, 2011, 08:08
Saw that coming earlier.  God help them.

Indeed - every single individual standing the watch out there at those plants is a full-blown and bona-fide hero in my book.

May God help them.
"But that's just my opinion - I could be wrong."
  -  Dennis Miller

Cycoticpenguin

I must say. This entire ordeal is kind of sobering. Thinking "oh we have backups to our backups to our backups" this kinda brings that into focus a bit.



ISOCS

Why are the EDGs alway in a hole with a lot of access controls when they should be propped up high. I can't be sure if this is a scare tactic or if they really have problems (liberal press and what sells). I know when they used seawater for cooling the reactor they ruined it.
ISOCS

Already Gone

Burying them in a watertight vault with a 100 foot snorkel mast might be the next wave.
"To be content with little is hard; to be content with much, impossible." - Marie von Ebner-Eschenbach

PJMcG

Quote from: Already Gone on Mar 14, 2011, 08:52
Burying them in a watertight vault with a 100 foot snorkel mast might be the next wave.

Only if they route the intake through the control room and put the head valve on the surface of the cooling intake (ocean, river, lake, etc.) so the thing can slam shut and suck the ops staffs eardrums out from time to time.  That should bring back some fond memories for some of us ... :)
"By its paw shall you know the lion."

hamsamich

suppresion pool damage on this one.  may be a different animal.  may be evacuating the plant.

caerbannog

Quote from: bitterone on Mar 14, 2011, 09:07
You or anyone else care to explain the suppression pool to a PWR guy, and why this is bad?

Possibly a pressure boundary lost?

PJMcG

Quote from: bitterone on Mar 14, 2011, 09:07
You or anyone else care to explain the suppression pool to a PWR guy, and why this is bad?

A BWR suppression pool serves a similar purpose, among other things, to the PZR Quench Tank (or Pressurizer Relief tank, depending upon the designer's nomenclature).

In general (finger quotes) PWR have larger containment buildings that accommodate primary leakage via volume.  Again, in general (fq) BWR have a suppression pool (a volume of water greater than that in a PRT or QT) into which the tail pieces downstream of safety (relief) valves are routed.  Thus when a relief valve lifts in a BWR the steam water mixture is routed into water in the liquid phase.  In a Mark I containment that is the torus; later containment designs have cylindrical suppression pools.

Why bad?  Suppression pool damage "COULD" (not saying it's present at Fukishiima) imply containment breech.  I actually just heard a report walking back the report of suppression pool damage.  It is still to early to know where the Unit 2 explosion took place and what damage occurred; although reports of radiation levels is higher than I have heard yet.

Additionally, the suppression pool can be used as a water source for Rx Core Isolation Cooling (RCIC); a system that uses steam from the vessel to spin a turbine driven pump that then injects water into the vessel via the feedwater lines.
"By its paw shall you know the lion."

hamsamich

Why bad?  Suppression pool damage "COULD" (not saying it's present at Fukishiima) imply containment breech.


this is why so bad in my opinion.  could be worse for the industry than just exploding RBs and degrading cores.  gotta protect health and safety of public. just more risk involved now.

PJMcG

"By its paw shall you know the lion."

roadhp

The New York Times put out a Google Satellite view that you can compare before and after pictures.  Here is the link:

http://www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html
Brave, brave Sir Robin, set forth from Camelot!!!!

jkj

  Quote from REUTERS:
Reuters) - Japan has told the U.N. nuclear watchdog a spent fuel storage pond was on fire at an earthquake-stricken reactor and radioactivity was being released "directly" into the atmosphere, the Vienna-based agency said.

I knew they should've got that pool tarp and garden hose from home depot earlier.

Man, between TEPCO's complete confusion and the media vultures-----what a horrorshow :'(

   There goes my job and the nuclear renaissance. The treehuggers are loving this.
Words fail me and pictures aren't much better.

"Never take no cut-offs, and hurry along as fast as you can."-- (Virginia Reed; member of Donner party.)

jkj

  Don't know what to believe but found this quote from the LA Times that quoted TEPCO as saying:

"-----Company officials said workers were not paying sufficient attention to the process, however, and let the pump stall, allowing the fuel rods to become partially exposed to the air.

Once the pump was restarted and water flow was restored, another worker inadvertently closed a valve that was designed to vent steam from the containment vessel. As pressure built up inside the vessel, the pumps could no longer force water into it and the fuel rods were once again exposed.-------"



Now after that FBR leak, contamination and cover up in Japan a few years back, along with the people getting cooked with steam from a ruptured pipe that hadn't been inspected in 28 years that occurred a few years later, and then the Tokaimura incident in 1999 with the uranium bucket pourers--- I'm beginning to wonder------ :-\ Japan's in the midst of a nightmare. :(
Words fail me and pictures aren't much better.

"Never take no cut-offs, and hurry along as fast as you can."-- (Virginia Reed; member of Donner party.)

Xenon_Free

I'm going to throw this out there for food for thought - this is not a hindsight 20/20 moment or anything just an observation.  I work at a nuclear power plant just like many of you.  I have always been proud of the robust design of the plants I've worked at, felt there was tremendous margin for safety.  I still believe this, despite recent tragic events.  The plants we have been discussing have experienced natural disasters exceeding their design criteria and they have individually held up better than expected.  Yet,  a single Act of God has made this situation far, far more challenging than it may have otherwise been had multiple units not been in close proximity to one another.  This is not a slam on multi-unit sites, just an apparent fact.  The sites of Fukushima 1 and 2 are separated by only a few miles (6 or 7  I believe) and they have vastly different outcomes from this one event.  
Plants can not be designed for a complete unknown, it can't be done - how could they design for an asteroid impact right next to a plant or a single act of extreme terrorism or an Earthquake and Tsunami of this strength AT THE SAME TIME?  However, with only one unit in the area the full resources at your disposal can be brought to bear to address one unit due to the one event.  And degrading plant conditions at one unit does not impede the ability to address plant conditions at another.  In this way, our ultimate goal of protecting the health and safety of the public can be better met.

There are beneifts to multi-unit sites to be sure, and likely there are design basis events that multi-unit sites would be better equipped to handle.  I am curious to hear other viewpoints.

XF

PJMcG

Quote from: Xenon_Free on Mar 15, 2011, 05:40
 I am curious to hear other viewpoints.

XF


XF,

I had similar thoughts cross my mind.  This is a disaster of biblical proportion and precise damage reports are still lacking.  For example, what is the exact state of the diesel generators, fuel tanks, make-up water tanks, pumps, valves, systems, etc. we know they're not available – but why is not clear yet.  I've been looking at the before and after aerial photography, many tanks and other equipment on the "ocean side" of the turbine buildings are still standing; whether they are full of sea water or not is unclear.

It's been hours since the explosion at Unit 2 and whether or not the suppression pool and containment have been breached is a matter of speculation.  There are reports of a 'spent fuel pool fire" huh?  How much flammable material is in the fuel pool?  The accident is still unfolding, there will be years to investigate, analyze, and respond to this information.  However, with all of that said, and as you prefaced your remarks, this is not to criticize ... but:

Whenever assets of any sort are localized and not diversified, the possibility exists for catastrophic loss.  This applies to securities (i.e., Enron stock), emergency diesels, food supplies, fresh water, and countless other assets.  Co-location of nuclear units has benefits (e.g., shipping, spent fuel storage, licensing, transmission lines, staff support and training, and countless others), but beyond three or four units does the threat to coincident damage due to a single event outweigh those advantages?  Off the top of my head, I don't think there is a US commercial nuclear location with more than three units (e.g., Palo Verde and Nine Mile Point; Dresden and SONGS have three, but unit 1 at both sites have been deactivated). 

Other thoughts that have crossed my mind:

These are Mark I and Mark II containments – later designs have passive safety features that are better suited for station blackout conditions.  But all designs evolve, automobiles didn't initially have seat belts.  That doesn't mean that we should abandon any design that has been improved.  As is part of our defense-in-depth culture, designs are continually reviewed and analyzed for improvements.  Moreover, it means that newer plant designs are the beneficiaries of lessons learned over sixty plus years of operating history.

Geographic diversity of emergency components would avoid collateral and simultaneous damage to adjacent units; in particular from Hydrogen explosions and tsunami.

Installing small capacity and low mass generators that can be located at higher elevations (i.e., enough capacity to run battery chargers to ensure DC control power is available).  I'm thinking a small gas turbine.  Somebody asked earlier, "why are the EDG always located in a hole?" (or words to that effect).  One reason, among others, is they're big and heavy and are a seismic risk at higher elevations.

I recall naval damage control equipment, in particular a P250 gasoline powered 250 GPM pump.  Locating that kind of equipment in at lease two separate locations may avoid delays in responding to major accidents.  There is of course a maintenance cost and ensuring availability with any additional equipment added to any site's assets.

I recall at San Onofre the seawater intake is significantly above sea level; it's been a while so I don't want to guess, but I think the large surf surge was a design consideration. 

Sorry for rambling ... but you asked ...

PJ
"By its paw shall you know the lion."



Frankie Love

To the experts...what system lines up to remove heat from the fuel pool? And, if those pumps are not functional, how long can spent fuel site with our residual heat removal pumps? I have wondered about the fuel pools because of their close proximity to the explosion area.


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