Japan's Nukes Following Earthquake

[drayer54]

I bet ole Gadhafi is sure glad to see a distraction like this going on so he can crush the hammer down without as much notice.
Anyways, couple of questions about Cesium that some of you may be able to answer for this nonqualified nub non licensed and incredibly non credible source....
If they are measuring Cesium levels in the air, doesn't that mean that the core has been exposed to the air and caused at least some kind of rupture/explosion and from my knowledge (and I could be wrong) doesn't Cesium have a violent reaction with air and is it possible that it could have either further damaged the core or in anyways been the source of the explosion? I read the hyrdrogen theories and those make sense, but I haven't been able to solve this question in my head about Cesiums role  ever since I heard it was detected in the air...

Also, what are the quals for these "Experts" on TV..... I feel like they just finished 'A' School.

[thenuttyneutron]

I bet ole Gadhafi is sure glad to see a distraction like this going on so he can crush the hammer down without as much notice.
Anyways, couple of questions about Cesium that some of you may be able to answer for this nonqualified nub non licensed and incredibly non credible source....
If they are measuring Cesium levels in the air, doesn't that mean that the core has been exposed to the air and caused at least some kind of rupture/explosion and from my knowledge (and I could be wrong) doesn't Cesium have a violent reaction with air and is it possible that it could have either further damaged the core or in anyways been the source of the explosion? I read the hyrdrogen theories and those make sense, but I haven't been able to solve this question in my head about Cesiums role  ever since I heard it was detected in the air...

Also, what are the quals for these "Experts" on TV..... I feel like they just finished 'A' School.

http://www.nndc.bnl.gov/chart/

Cesium 137 is near one of the peaks for the fission product yield curve.  There are no natural sources for it either.  Detecting it in the air means the was clad failure somewhere.  We will not know how bad the core was damaged for a while.

[darlingetoile]

The question that keeps crossing my mind, is if there were severe earthquake warnings why did the Shift Manager/Site Manager not order the units placed into Guaranteed Shutdown State or at least temporarily shut them down during that time?

[thenuttyneutron]

The question that keeps crossing my mind, is if there were severe earthquake warnings why did the Shift Manager/Site Manager not order the units placed into Guaranteed Shutdown State or at least temporarily shut them down during that time?

They did shut them down.  You can't turn off decay heat and thus you must keep core cooling going.  

This is the "special" part of nuclear technology.  The core will continue to make decay heat long after the plant is shutdown.  If you don't cool the core, it will find a way to reject the heat for you in bad ways.  It does this by raising the delta T between the fuel and the surroundings.

Decay Heat is what gives me a huge pucker factor during an outage when we are drained to low levels for pulling the head and the time to boil is measured in minutes.

[Cycoticpenguin]

I bet ole Gadhafi is sure glad to see a distraction like this going on so he can crush the hammer down without as much notice.
Anyways, couple of questions about Cesium that some of you may be able to answer for this nonqualified nub non licensed and incredibly non credible source....
If they are measuring Cesium levels in the air, doesn't that mean that the core has been exposed to the air and caused at least some kind of rupture/explosion and from my knowledge (and I could be wrong) doesn't Cesium have a violent reaction with air and is it possible that it could have either further damaged the core or in anyways been the source of the explosion? I read the hyrdrogen theories and those make sense, but I haven't been able to solve this question in my head about Cesiums role  ever since I heard it was detected in the air...

Also, what are the quals for these "Experts" on TV..... I feel like they just finished 'A' School.

Bwr dude. Remember that the primary side IS the secondary side. A fuel element failure could theoretically get fission particulate entrained in thee steam system and if we are venting srv's to atmosphere, we may be releasing it to the public. Does that mean the vessel is damaged? Not really.

Media does what it wants. You should knw that by now.


Julian, reports I read said they had a 20 second warning before it hit.

[drayer54]

Bwr dude. Remember that the primary side IS the secondary side. A fuel element failure could theoretically get fission particulate entrained in thee steam system and if we are venting srv's to atmosphere, we may be releasing it to the public. Does that mean the vessel is damaged? Not really.

Media does what it wants. You should knw that by now.

I get that actually. I am saying that I thought the Cs actually being released would be an indicator of something more serious.

[Matthew B]

A Hydrogen explosion wouldn't have produced any smoke, but there would have been a fireball. 

Hydrogen combustion doesn't produce a visible flame.

Carbon, carbon monoxide and carbon dioxide all glow visibly when hot.  The oxidation of carbon releases visible light.  That's what produces the light for most fires we are familiar with.

Hydrogen and steam do not glow until they are heated much hotter (too much energy needed to kick a valence electron free).  The combustion produces ultra-violet light.   You can see a faint blue glow in rocket exhaust, but that is from shock waves.

I think the "smoke" is concrete dust.   There was no explosion when the world trade center collapsed, but there was a whole lot of concrete dust.

[Matthew B]

that looks more like a turbine building explosion to me that blew away the blowout panels on the refueling floor. wanna bet they released hydrogen from the generator and it went poof?

In the generators I'm familiar with, the hydrogen is kept in using turbine lube oil.  On a loss of all AC power, the turbine building battery powers a DC pump to provide lube oil as the turbine as the turbine coasts down.  Before the battery goes dead, someone needs to go out and open the vent to dump the hydrogen above the roof.  If no-one opens the vent valve, the hydrogen will vent out along the shaft at both ends of the generator.  With 60-75 PSI of hydrogen in the generator, a whole lot hydrogen will vent into the turbine building quickly.

[PJMcG]

Can someone with GE Mark I containment knowledge describe the drywell venting process?

Does the drywell vent path go through the off-gas system?

[Marlin]

I have heard that some people were treated for radiation sickness but that does not jive with the levels of radiation that I have seen published. Media hype I am sure, has anyone seen any real numbers? Today's update lists one worker who received 100mSv enough to see blood changes with a baseline but not high enough I would expect treatment.

[PJMcG]

I found this interesting:

http://www.reuters.com/article/2011/03/11/japan-nuclear-idUSL3E7EB26V20110311

Not indicating a preference either way, but as far as I can tell all eleven Japanese plants that went down due to the earthquake are BWR of various generations.  I'm sure that is due to the majority of Japanese nukes being BWR and not a rellection of plant reliability.  It does remove the confusion associated with ECCS variations across BWR and PWR.

I like others on this board hope and pray for safe outcomes in all cases and express my deepest sympathy for all people affected by this unprecedented tragedy.

[debib]

I'm keeping the operators in my thoughts.

[Xenon_Free]

Can someone with GE Mark I containment knowledge describe the drywell venting process?

Does the drywell vent path go through the off-gas system?

Sure,  It goes basically like this.

Normally, with all power available the containment would be vented by the following:

1) Check ventilation path way and ensure it is lined up - Reactor Building ventilation exhaust fans are running for instance since that is the normal pathway.
2) Check several different Raditation Monitors in the release pathway as well as the drywell process radiation Montiors to ensure there will be NO effluent release of contamination.
3)  Open a valve inside the drywell remotely and then open a valve outside the drywell - also remotely
4)When desired pressure reached secure lineup.

With no power available it would go something like this:

1)Check available instrumentation and rad monitors to determine release
2) Lineup drywell using alternate vent paths available OUTSIDE of the drywell
3)Ventilation pathway is still used – that is; it ties into the same exhaust path as other vents – this makes sense, since one always wants to thoroughly monitor and release from an elevated point
4) commence release and sample the effluent or monitor remotely if available to determine release rate.
5)  Stop if release rates are reached, unless directed otherwise by emergency procedures

There are methods to release into the reactor building through alternate valve lineups – this will keep more of the "bad stuff" within the facility.  Unfortunately if there is H2 in the vent stream this operation can be hazardous.

Make sense?

[Sun Dog]

one worker who received 100mSv enough to see blood changes

You would expect to see blood changes at that "low" of an acute exposure?  I thought the first measurable blood changes would occur at about 25 Rem acute.

[Cycoticpenguin]

I found this interesting:

http://www.reuters.com/article/2011/03/11/japan-nuclear-idUSL3E7EB26V20110311

Not indicating a preference either way, but as far as I can tell all eleven Japanese plants that went down due to the earthquake are BWR of various generations.  I'm sure that is due to the majority of Japanese nukes being BWR and not a rellection of plant reliability.  It does remove the confusion associated with ECCS variations across BWR and PWR.

I like others on this board hope and pray for safe outcomes in all cases and express my deepest sympathy for all people affected by this unprecedented tragedy.

considering most of their plants are of the BWR variety, Id have to say its more incumbent on their location vice their "types"...

[MM1 subnuke]

Not being in the nuke industry anymore, (ex navy sub mm nuke myself,did 9 years) I haven't been able to read any of the news nor watch tv reports on this incident.  The "credible" sources make me laugh.  I've forgotten more than most of these guys know, and its hard to sift through all the BS.  my question to you SRO guys is this, IF, and that's a really big IF, they are venting to atmosphere, what type of spread are we looking at?  I say this not knowing what type of fuel they use in their cores, is it enriched uranium, do they have half-nium, so on and so forth.  What are the chances of any fission product release?

[tr]

Not indicating a preference either way, but as far as I can tell all eleven Japanese plants that went down due to the earthquake are BWR of various generations.  I'm sure that is due to the majority of Japanese nukes being BWR and not a rellection of plant reliability.

The reactors apparently tripped on high seismic activity.  Plants near earthquake zones often have a direct reactor trip on seismic activity as a part of their reactor protection system.  I would read the BWR versus PWR issue as merely the fact that the plants closest to the earthquake were BWR plants.

[Cycoticpenguin]

Not being in the nuke industry anymore, (ex navy sub mm nuke myself,did 9 years) I haven't been able to read any of the news nor watch tv reports on this incident.  The "credible" sources make me laugh.  I've forgotten more than most of these guys know, and its hard to sift through all the BS.  my question to you SRO guys is this, IF, and that's a really big IF, they are venting to atmosphere, what type of spread are we looking at?  I say this not knowing what type of fuel they use in their cores, is it enriched uranium, do they have half-nium, so on and so forth.  What are the chances of any fission product release?

Im no SRO, but 1) venting to atmosphere will most certainly release radioactive nuclides 2) spread will be dependent on weather conditions 3) BWR's use varied enrichments but nothing even close to navy. We're talkin around 4-7%, depending on location in the core 4) uranium fuel 5) borated rods, not hafnium 6) fission product release has already occurred.

I dont think we've seen any set numbers on the release yet.

[PJMcG]

Sure,  It goes basically like this.

Normally, with all power available the containment would be vented by the following:
...

With no power available it would go something like this:
...

There are methods to release into the reactor building through alternate valve lineups – this will keep more of the "bad stuff" within the facility.  Unfortunately if there is H2 in the vent stream this operation can be hazardous.

Make sense?

XenonFree,

Thanks!  And yes that makes sense.

What does not make sense is, no mention of a means to vent through OFF GAS system.  It would seem to me that routing the drywell gas through off-gas would strip particulate and give short lived isotopes more time to decay before venting to the atmosphere.  

In the later containment designs, is this an option?  

Thanks again!

[Marlin]

You would expect to see blood changes at that "low" of an acute exposure?  I thought the first measurable blood changes would occur at about 25 Rem acute.

   I did say with a baseline which would drop the standard 25 Rem limit for detection to 5 Rem. Baseline blood count I don't think is done much anymore for radiation as it is for lead and beryllium.

[DDMurray]

A senior SRO at my PWR passed this to us:


http://www.washingtonpost.com/wp-srv/special/world/japan-nuclear-reactors-and-seismic-activity/?hpid=topnews

[desertdog]

I have heard that some people were treated for radiation sickness but that does not jive with the levels of radiation that I have seen published. Media hype I am sure, has anyone seen any real numbers? Today's update lists one worker who received 100mSv enough to see blood changes with a baseline but not high enough I would expect treatment.

The first reports of radiation sickness were immediately following the utility's report of several workers going to the hospital with broken bones from the Unit 1 explosion.  Contaminated injured man perhaps?  Like everything else in the news this weekend, not enough info.

[nukerecruiter]

Not surprised that the NYTimes was first to post an article like this:

U.S. Nuclear Industry Faces New Uncertainty
http://www.nytimes.com/2011/03/14/science/earth/14politics.html?_r=1&hp

Also- thanks for this great thread. Have been spending the last few hours reading up on here. Knew I could count on all of you for some acurate information in this sea of moronic reporting.

[Already Gone]

Wow! This thread is on fire.

Anyway:
First, yes, I am aware that Hydrogen combustion is invisible, but there would still be a flash fro other combustible particles in the air.  It was a brief flash that looked like a rising bubble.  To me, it is consistent with a Hydrogen ignition.

Second, Cesium in the air, does NOT necessarily mean a fuel failure or a cladding failure.  Tramp Uranium impurities in the cladding will release fission products directly to the reactor coolant.  Also, Xenon (an abundant fission product gas) decays to Cs-137.  Xenon and Cesium from Tramp Uranium, plus Xenon from a possible gap release, can cause the presence of Cesium in the plume.

Third, I am stunned that Robert Bezell from NBC News has finally been a voice of calmness and reason from a major news outlet.  He will be proven to have been correct that this is NOT a deadly situation.  Compared to the earthquake, the tsunami, the loss of structural integrity in housing and public buildings, the breakdown of physical infrastructure, the unsanitary conditions due to loss of water treatment and sewage systems, the hydrocarbons and toxic chemicals being released by the burning refineries, the impact on hospitals, the delay and over-taxing of emergency response,  ....   the overheated nuclear plant is NOT the biggest - or even one of the top ten - threats to public health in Japan.

[MM1 subnuke]

The first reports of radiation sickness were immediately following the utility's report of several workers going to the hospital with broken bones from the Unit 1 explosion.  Contaminated injured man perhaps?  Like everything else in the news this weekend, not enough info.

God, not the contaminated injured man drill.  I always got stuck having to be at the decon station for hours.  Just scrub harder damnit.