Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[AtomicWombat]

:uhh: Prof. Kaku's argument is sound on the premise of preparing for a worst case situation. Since Chernobyl was a remote site, entombment was an easy option. I think Japan will wait to see if restored power will let them get a better hand on the situation. If the seawater injection has worked and re-flooding the spent fuel pools is carried out, then only a lengthy core stabilization, facility clean up and decommissioning is left. Oh, and the compilation of a lessons learned report that will fill a Harvard size library.

"If this spirals out of control we could use a good chunk of northern Japan", Michio Kaku

I assume this is hyperbole. I can't see it being worse than a long-term 30 km (or so) exclusion zone.

On the other hand I think his comments about the Japanese leadership loosing touch with reality are accurate.

I was disappointed about what he didn't say. There is an urgent need for much better assessment of the true state of the reactors and SFPs. I read http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA335076&Location=U2&doc=GetTRDoc.pdf" and it was clear that for some time the operators were working on the false assumption that the reactor was still intact. Too often I hear from Japan, "we think this", "we think that", "this glint of light means the SFP has water in it", etc.

TEPCO & the Japanese government seem to be flying blind and their actions on the ground reinforce this impression.

 

[mattm2]

Possible cause of hydrogen explosion of reactors 1 and 3 is published by http://allthingsnuclear.org/post/3940804083/possible-cause-of-reactor-building-explosions" - an excellent article

What bothers me is quote "A little-known test performed decades ago at the Brunswick nuclear plant in North Carolina may hold the key to answering that question." - why little-known - this is a design limitation/fault common to many nuclear power stations. If this had been common knowledge in the nuke industry safety manuals and emergency procedures may have been rewritten - I am sure they are now being re-drafted.

Now at Fukushima containment vessel pressure has been http://www.jaif.or.jp/english/aij/110319FukushimaEventStatus-14e.pdf" *1) to be steady at .140 to .150 MPa_abs which is about the same as 70PSI Gauge. Now reactor vessels 2 and 3 are reported near 0 pressure Guage that is the pressure inside the the reactor vessel is the same as the pressure in the containment vessel leading to the conclusion that the reactor vessel is breached and the containment vessel 'auto-vents' as described in the article.

It is also reported that sea water flooding into the reactor cores is taking place continually one of two things can happen
1- worst case it boils of and steam is vented as above then slowly a massive NaCl crust must be developing
2- best case the reactors have cooled and the containment vessel slowly filling with water

*1) Reactor 3 CV pressure 0.045MPa_abs must be a typo as it is a vacuum and I think should read as 0.145MPa_abs as in previous reports

If there is little/no pressure in reactor core 2 and 3 and; if, water is being fed into those cores and; if the core is breached: would not there be a massive amount of steam generated? Water under no pressure turns to steam easier than with pressure added. How fast does water go into the core? There is no steam coming from number 2 is there? Have they released the results of the IR temperature readings taken by aircraft and/or sat?

 

[AntonL]

Off Topic: Fishing boat and tsunami wave

Off topic: Fishing boat powers through tsunami wave http://www.youtube.com/watch?v=3fqyOpqnJyw&feature=player_embedded"

 

[daumphys]

How about this equation?

rate equation

-Q_out + Q_generated = Q_accumulated
Q_out = U A (del T)_log_system_min

The Problem is Q_accumulated value, it makes temperature increasing.

Normal reactor pump cooling U=high, A=high, (del T)_log_system_min = low(high pressure)
Accident recover cooling U= low, A=low, (del T)_log_system_min = high(atmosphere)

Increasing A is God's will.

If Q_generated is not too high, accident recovery cooling method might give some effect.

 

[Astronuc]

What bothers me is quote "A little-known test performed decades ago at the Brunswick nuclear plant in North Carolina may hold the key to answering that question." - why little-known - this is a design limitation/fault common to many nuclear power stations. If this had been common knowledge in the nuke industry safety manuals and emergency procedures may have been rewritten - I am sure they are now being re-drafted.

I suspect the utility and GE understood the results, and that it exceeded the design requirement. If it was successful, then it is probably little known, because a success is not a concer.

Now at Fukushima containment vessel pressure has been http://www.jaif.or.jp/english/aij/110319FukushimaEventStatus-14e.pdf" *1) to be steady at .140 to .150 MPa_abs which is about the same as 70PSI Gauge. Now reactor vessels 2 and 3 are reported near 0 pressure Guage that is the pressure inside the the reactor vessel is the same as the pressure in the containment vessel leading to the conclusion that the reactor vessel is breached and the containment vessel 'auto-vents' as described in the article.

*1) Reactor 3 CV pressure 0.045MPa_abs must be a typo as it is a vacuum and I think should read as 0.145MPa_abs as in previous reports

Let's be careful with conversion factors. One (1) atm = 14.696 psi = 0.101325 MPa, so 0.14 MPa = 20.3 psi, and 0.15 MPa = 21.76 psi. 0.1 MPa = 14.50377 psi.

Earlier numbers reported in the media were a design presure of 0.4 MPa (58 psi), which is less than 0.4274 MPa (62 psi), but higher pressurizations of up to 0.84 MPa (122 psi) in unit 1 before the H-explosion.

One must also be careful in differentiating betwee absolute, gage and differential pressures. The media is not so careful, and some professionals sometime misstate.

It is also reported that sea water flooding into the reactor cores is taking place continually one of two things can happen
1- worst case it boils of and steam is vented as above then slowly a massive NaCl crust must be developing
2- best case the reactors have cooled and the containment vessel slowly filling with water

The deposition of salt is of interest. The best case now is to have the RPV filled with water. I expect that containment is flooded to the extent possible.

 

[AntonL]

Let's be careful with conversion factors. One (1) atm = 14.696 psi = 0.101325 MPa, so 0.14 MPa = 20.3 psi, and 0.15 MPa = 21.76 psi. 0.1 MPa = 14.50377 psi.

Appologies - I made a mistake in the conversion I will edit the original post

 

[TCups]

It would be interesting to see some high res satellite imagery of the FK site in the IR and XRay spectral ranges. Surely there must be some that have the capability that could be tasked to obtain them. Anyone know of any source for high res imagery of this source that might be accessible to the public? Or are they all "classified" or otherwise restricted by the DOD?

The "official news this AM seems to be "No news" -- perhaps a good thing.

Here's Digital Globe Image (from another website) -- says all IR imagery still "Top Secret"
http://www.zerohedge.com/article/pr...-fukushima-thermal-imaging-continues-be-top-s

http://www.zerohedge.com/sites/default/files/images/user5/imageroot/von%20havenstein/japan_earthquaketsu_fukushima_daiichi_march18_2011_dg.jpg

http://www.digitalglobe.com/index.php/27/Sample+Imagery+Gallery

Japan's population density

http://web.stratfor.com/images/asia/map/Japan_pop_800.jpg

 

[Astronuc]

It would be interesting to see some high res satellite imagery of the FK site in the IR and XRay spectral ranges. Surely there must be some that have the capability that could be tasked to obtain them. Anyone know of any source for high res imagery of this source that might be accessible to the public? Or are they all "classified" or otherwise restricted by the DOD?

The "official news this AM seems to be "No news" -- perhaps a good thing.

I'm not sure that thermal imaging is classified, or does one refer to thermal imaging from a satellite. I imgine the security agencies do not want to reveal the true capabilities of their systems.

On the ground, thermal imaging is available. When I was a university student working in the university facilities department, I worked with an energy auditor whose specialty was thermal imaging of electrical equipment. He used a special liquid nitrogen cooled camera to image key elements of the electrical transmission and distribution system, e.g., transformer station and connections. That was in the mid 1970s.

I'm not sure about X-ray imaging at distance.

 

[antonyk]

I'm not sure that thermal imaging is classified, or does one refer to thermal imaging from a satellite. I imgine the security agencies do not want to reveal the true capabilities of their systems.

On the ground, thermal imaging is available. When I was a university student working in the university facilities department, I worked with an energy auditor whose specialty was thermal imaging of electrical equipment. He used a special liquid nitrogen cooled camera to image key elements of the electrical transmission and distribution system, e.g., transformer station and connections. That was in the mid 1970s.

I'm not sure about X-ray imaging at distance.

The utility I work for has a handful of IR cameras used exactly for what Astronuc just mentioned. They are hand portable and also can be used some distance away (from helicopters). As TEPCO is a very large utility with extensive transmission and distribution equipment, it would be safe to assume that they have these and hopefully are using them.

 

[TCups]

Possible cause of hydrogen explosion of reactors 1 and 3 is published by http://allthingsnuclear.org/post/3940804083/possible-cause-of-reactor-building-explosions" - an excellent article

What bothers me is quote "A little-known test performed decades ago at the Brunswick nuclear plant in North Carolina may hold the key to answering that question." - why little-known - this is a design limitation/fault common to many nuclear power stations. If this had been common knowledge in the nuke industry safety manuals and emergency procedures may have been rewritten - I am sure they are now being re-drafted.

Now at Fukushima containment vessel pressure has been http://www.jaif.or.jp/english/aij/110319FukushimaEventStatus-14e.pdf" *1) to be steady at .140 to .150 MPa_abs [STRIKE]which is about the same as 70PSI Gauge[/STRIKE]. Now reactor vessels 2 and 3 are reported near 0 pressure Guage that is the pressure inside the the reactor vessel is the same as the pressure in the containment vessel leading to the conclusion that the reactor vessel is breached [STRIKE]and the containment vessel 'auto-vents' as described in the article[/STRIKE].

It is also reported that sea water flooding into the reactor cores is taking place continually one of two things can happen
1- worst case it boils of and steam is vented as above then slowly a massive NaCl crust must be developing
2- best case the reactors have cooled and the containment vessel slowly filling with water

*1) Reactor 3 CV pressure 0.045MPa_abs must be a typo as it is a vacuum and I think should read as 0.145MPa_abs as in previous reports

Edit: As pointed out later pressure conversion is wrong hence wrong part struck out

AntonL:
This proposed explanation seems quite plausible but in retrospect, even more worrisome to me.

If the hydrogen gas were leaking at the drywell head, then that leak was inside the concrete containment, and so presumably was at least part of the explosion. I am wondering about the likelihood that the concrete shield plug(s) were blown off the top of the secondary (concrete wall) containment.

Although, in retrospect, a lay person would have to conclude that any hydrogen arising from a reaction involving the fuel rods would have to arise from within the reactor vessel, I had considered it got from there to the building's interior by a controlled venting process, not leakage from the drywell head, then concrete containment.

One must assume, for this mechanism to be the cause, that the concrete shield plug would not be fitted tightly enough to prevent leakage of H2. It also seems a reasonable assumption, in retrospect, that the concentration of H2 might be significantly higher under than over the concrete shield plug.

Has anyone made an assessment of the probability that the H2 explosions at Units 1, 2, and 3 blew the concrete containment plugs off like the cork on a bottle of cheap champaign?

http://media.tumblr.com/tumblr_li9czl6f4v1qbnrqd.jpg

If the diagram is accurate, it also gives a bit more insight of a hypothetical course any molten material might take from the floor of the SFP to the building's exterior.

Also, in the videos of the explosion of unit 3, I seem to remember something large and heavy falling from the vertical plume just to the side, and that someone pointed out that the blast at (unit 3?) was more vertically directed, like a cannon shooting straight upward. I have to review that video again.

Yes -- here --

Something large and heavy (who knows what), curls off to the left and comes down over the left hand tower in the video. What are the odds if it were the plug, it might be reasonably intact and visible among the debris on the ground. Back to the satellite images . . .

Hmmm. No way to tell, but it gives pause to think what might have fallen through the roof of the building in front of unit 3, doesn't it?
http://www.zerohedge.com/sites/default/files/images/user5/imageroot/von%20havenstein/japan_earthquaketsu_fukushima_daiichi_march18_2011_dg.jpg

Here's a link to the video:

http://www.youtube.com/watch?v=P6-BEOWKpAU&NR=1

I understand this is, again, all speculative, but I am compelled to try to understand what my eyes are telling me.

 

[jensjakob]

That plug looks too heavy for me to be blown off. What are the calculations?

 

[Naty1]

I wish anyone would publish SOME radiation readings ...but the one's that would be most interesting would be in the 50 mile and 15 mile evacuation areas around Fukushima...

Forgive me, but I don;t trust the reporting of anyone who does not provide some backup in terms of actual readings ...

Does anyone know how well on site control rooms are shielded?? There must be some standards...And to what extent is protection compromised when power is lost and presumably filtered ventilation fails??

 

[AntonL]

AntonL:

Has anyone made an assessment of the probability that the H2 explosions at Units 1, 2, and 3
blew the concrete containment plugs off like the cork on a bottle of cheap champaign?
.

As pictures are large, and forum entries get stretched beyond the cpu screen, I made pictures to thumbs with hyperlinkshttp://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi_march18_2011_dg.jpg"

and http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi_march14_2011_dg.jpg"

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichiov_march14_2011_dg.jpg"

and

http://www.digitalglobe.com/downloads/featured_images/japan_earthquaketsu_fukushima_daiichi3_march16_2011_dg.jpg"

If plug popped off
Unit 1: No - roof seems to have collapsed in tact covering SFP, etc no plan features visible
Unit 2: no comment, however unit 2 is constantly emitting steam through a gap on east wall
which is said to be purposely opened. What is boiling?
Unit 3: Too much debris on roof to make any conclusions, however on March 14, shortly after explosion
steam from central part of reactor building. Note the explosion dust being carried out to sea.

 

[TCups]

That plug looks too heavy for me to be blown off. What are the calculations?

Beyond the ballistics of a 300 grain bullet, I cannot tell you. With a fuel (H2) + air explosion, volume of the reactants would have to be known. But in viewing the video and the subsequent damage, in general (as in "it looks like"), it looks like to me there was a sufficient release of energy to blow several of those plugs sky high. But then, I do not know the point where most of the energy from the blast was initially released. How big is the hole in the roof? Maybe 5-10 meters across?

Hmmm . . . no. Speaking of bullets, those are "bullet" tracks that grazed the roof of that building from side to side with one of the heavier "bullets" falling through the roof. They came from an outward blast from Unit 3 and were probably the large, reinforced concrete panels between the structural concrete beams. About the right size and number, right?

Which now gives pause to another consideration regarding Unit 4. Maybe that square hole in the side was initially a "bullet" hole.

 

[AntonL]

Which now gives pause to another consideration regarding Unit 4. Maybe that square hole in the side was initially a "bullet" hole.

No, satellite picture of March 14 posted two posts earlier just after the explosion show building of unit 4 intact

 

[rhody]

In the https://www.physicsforums.com/showpost.php?p=3197547&postcount=539" above, first picture, from left to right, (edited 1:06pm) first long rectangular building, see the whole described by TCups in the previous post ? TCups said he thought he saw something large and heavy fall from the video which had the big vertical plume. In his post he said to the left of the tower, I am wondering out loud if that could be remnants of the "plug" he spoke of ? Because the image is rotated 180% and is now right oriented it fits perfectly with what he claims to have seen. Could the plug or remnants of it be inside the building ? Had we not been given access to the high res photo, this would not be possible, way to go, AntonL. You guys are doing with access to free information what is needed, trying to piece the puzzle together, and I must say doing a fairly amazing job at it. Keep up the good work.


Rhody...

 

[TCups]

Everything I see says the greatest force of the blast at 3 was sideways. Another "bullet" hit in a building in back of unit 3. But most of the girder structure of the roof seems intact. I can't see any good candidates for the "plug". Sure wish we had thermal imaging to study.

 

[Maxion]

Everything I see says the greatest force of the blast at 3 was sideways. Another "bullet" hit in a building in back of unit 3. But most of the girder structure of the roof seems intact. I can't see any good candidates for the "plug". Sure wish we had thermal imaging to study.

That is true, there are quite a lot of IFs in the situation. We don't even know how the reactor in the GE test differs or doesn't from Fukushima 1-3. But the round hole in the turbine building infront of 1-3 is quite interesting in my opinion. I would say the evidence is in favor of the containment buildings cap blowing off, but there are very many if's to be able to say so conclusively.

What do you think, Astronuc? I'd say you would be the best person to guestimate based on the info we have.

 

[Astronuc]

Regarding the plug covering the reactor cavity, I believe the expectation is the hydrogen explosions occurred in the upper or secondary containment, i.e., in the volume of the metal building structure atop the concrete containment. The explosion would then be above the plug.

As far as I know, the emergency plan would be to flood containment with water, which would prevent accumulation of hydrogen, but perhaps there is some voiding (?). Hydrogen rises, so it goes up by the most available pathway. There is a venting system from containment to the tall stacks (towers) that one sees adjacent to each reactor building. It appears that Units 1 & 2 share a stack. Ideally, the atmosphere from containment is filtered and where possible, delayed to allow decay of short half-lived fission gases.

An explosion in containment would be a concern. A strong blast over the spent fuel pool, especially with a reduced pool level would also be of concern with respect to the integrity of the wall, particularly the wall toward the outside of the building.

 

[rhody]

FYI

Not to interrupt the train of thought but here is http://www.iaea.org/newscenter/news/tsunamiupdate01.html" as of March 19, 2011.
I haven't read it fully and digested it yet, it may or may not shed some light on this discussion.
I have included a screen grab of a damage assessment table in the link. Another piece of the puzzle, have at it guys...

Rhody...

edit: P.S. AntonL made a similar post in https://www.physicsforums.com/showpost.php?p=3196974&postcount=521" above, it is the same data, with a greater level of detail than the official IAEA chart in thumbnail above, compare if you wish...

 

[warren_c]

Video of a fire truck spraying water on no. 3:

 

[AntonL]

But the round hole in the turbine building infront of 1-3 is quite interesting in my opinion.

I do not think it is a round hole, video taken on a cloudy day and we would not see into the generator hall as it would be too dark. I think that black is some steel cladding with a roof beam lying on top, similar roof beams from unit 3 can be seen scattered.

 

[TCups]

I do not think it is a round hole, video taken on a cloudy day and we would not see into the generator hall as it would be too dark. I think that black is some steel cladding with a roof beam lying on top, similar roof beams from unit 3 can be seen scattered.

Look again. Clearly, 4 large pieces of debris blasted outward from the wall of Unit 3. Two of 4 chunks traversed the roof of the turbine bldg, damaging the far wall of the turbine bldg. Two more hit the near wall of the turbine bldg, then made it part of the way, then fell through the roof. These were likely the concrete panels between the structural columns of Unit 3.

http://i306.photobucket.com/albums/nn270/tcups/Picture1-3.png

 

[AntonL]

Look again. Clearly, 4 large pieces of debris blasted outward from the wall of Unit 3. Two of 4 chunks traversed the roof of the turbine bldg, damaging the far wall of the turbine bldg. Two more hit the near wall of the turbine bldg, then made it part of the way, then fell through the roof. These were likely the concrete panels between the structural columns of Unit 3.

Yes I can see the 'shaving' marks left by horizontal moving bodies, but these do not cause holes, for holes we need a vertical impact. Also note the black area is the end of the skid mark, so we looking at the body that marked the roof, other two skid marks damaged the east side fascia and whatever caused the marking then fell to the ground.

I still firmly believe the roof of the generator hall has not been penetrated and is intact other than the skid marks and fascia damage.

 

[romillyh]

Video of a fire truck spraying water on no. 3:

And, in case it's any help, story of same with diagram of unmanned truck and seawater pump unit in The Japan Times:

http://search.japantimes.co.jp/cgi-bin/nn20110320a1.html

Aimed at cooling spent MOX in no. 3 pool. We live in hope. (Apols if someone has already posted link -- I checked but can't see it)

 

[Reno Deano]

TEPCO's latest update. I am assuming they mean that no water has leaked from the RPV to the Primary containment, which is questionable.

Press Releases

Press Release (Mar 19,2011)
Plant Status of Fukushima Daini Nuclear Power Station (as of 0:00 pm March 19th)


No New Developments since 9:00pm, 19th March

Unit Status
1 • Reactor cold shutdown, stable water level, offsite power is
available.
• No cooling water is leaked to the reactor containment vessel.
• Maintain average water temperature at 100°C in the pressure
restraint.
2 • Reactor cold shutdown, stable water level, offsite power is
available.
• No cooling water is leaked to the reactor containment vessel.
• Maintain average water temperature at 100°C in the pressure
restraint.
3 • Reactor cold shutdown, stable water level, offsite power is
available.
• No cooling water is leaked to the reactor containment vessel.
• Maintain average water temperature at 100°C in the pressure
restraint.
4 • Reactor cold shutdown, stable water level, offsite power is
available.
• No cooling water is leaked to the reactor containment vessel.
• Maintain average water temperature at 100°C in the pressure
restraint.
other• In the Unit 1, 2, 3 and 4, which automatically shut down due
to the Tohoku-Chihou-Taiheiyo-Oki Earthquake on March 11th, 2011,
we had been preparing measures for decreasing the pressure of each
reactor containment vessel since March 12th. However, on March
17th, we released such preparation in all of the Units.

 

[turbo]

Our military has some very capable autonomous/remote controlled rotor-wing aircraft with visual/IR imaging systems, like the RQ-8A Fire Scout. It is hard to believe that such drones have not been tasked with getting better images than the ones that the public can access. I can understand the military not wanting to disclose the capabilities of their surveillance systems, but this is a pretty dicey situation and more accurate imaging (and not just top-down shots) could be very valuable in assessing damage and charting out a course of action for each damaged reactor.

 

[LanceV]

I wish anyone would publish SOME radiation readings ...

The GRS has been compiling the some of the known radiation data in some nice diagrams (in german but should be self-explanatory):
http://www.grs.de/informationen-zur-lage-den-japanischen-kernkraftwerken-fukushima-onagawa-und-tokai
Especially
http://www.grs.de/sites/default/files/Radiation-Data_Daiichi_20110319-1800.pdf and
http://www.grs.de/sites/default/files/ODL-Werte-Poll_20110319_1715_0.pdf
are interesting.

 

[M. Bachmeier]

Japan reluctant to disclose footage of power plant taken by U.S. drone


http://mdn.mainichi.jp/mdnnews/news/20110319p2a00m0na005000c.html

 

[Angry Citizen]

Note: This is regarding the second link.

It is by no means 'self-explanatory' -- I had to utilize translation software. It is saying that radiation levels less than half a kilometer away from all six reactors has peaked at about five millisieverts/hour for the past several days. This seems to be good news. The purple spikes correlate to the explosions, with the largest one also correlated with the fire at unit 4. I want to know why the main building (Hauptgebäude) is continually reading what appear to be spikes -- large increases followed by exponential decrease.

 

[MadRocketSci2]

My understanding is that when they perform steam venting operations, there is a brief spike in the observed radiation.

 

[83729780]

TEPCO's latest update. I am assuming they mean that no water has leaked from the RPV to the Primary containment, which is questionable.

Press Releases

Press Release (Mar 19,2011)
Plant Status of Fukushima Daini Nuclear Power Station (as of 0:00 pm March 19th)

not Daiichi

 

[edmundredmark]

Lurker de-cloaking here partly to say thanks to the knowledgeable participants and excellent photo researchers in this thread and partly to make a few random comments:

A) On useful vs. stupid coverage of this event: I've been using mainly the New York Times and Kyodo News for news, and I think they've been, not perfect, but pretty thorough and accurate. (For instance, somebody asked a few pages back 'where are our Predator drones'? Well, that was answered by the NYT a day or two ago: there is indeed one in use, and other military surveillance assets normally targeted at North Korea are also being used over the Fukushima site.) With the Times, you have to keep checking back, however -- they do this kind of running update to their main article, rather than publishing a new story every time something new happens.

I've also found the information from the Union of Concerned Scientists and the MIT Dept. of Nuclear Engineering to be valuable.

B) Seems clear that the central issue here at Fukushima is the extended "station blackout". As a layman who went to college (and only a state college, to boot!) and has some decent reasoning capabilities, I'm more than a little aghast that, apparently, in all the emergency contingency planning for NPPs it is simply assumed that a station blackout could never last more than 4-8 hours. I don't think NPPs should be forced to plan for events as unlikely as, say, an attack by Martians, but an event that could knock out grid power and your only set of emergency generators for more than 4 (or, at best, 8) hours? C'mon guys. I think that's grossly irresponsible safety planning, and though I'm not anti-nuclear at all, I am very strongly anti-stupidnuclear.

I look at San Onofre and Diablo Canyon in earthquake-prone California and think they've got to do some serious, and quick, thinking about how to increase redundancy and survivability in their power supplies. Just simply putting some additional diesel generators in a hurricane/tornado/earthquake hardened building a few hundred feet up the hill to a nice elevation, and running some electrical cable underground to the reactor buildings would seem like a simple, and prudent, step that could be taken pretty much now. If I lived in California I would push my elected officials to mandate it now (and be willing to pay a special sales tax or something to pay for it). But I majored in English, so what do I know.

C) One thing on media coverage that I think would be useful is the information that one of the health risks being talked about most here, which is thyroid cancer induced by accumulation of Iodine-131 in the thyroid gland, is actually not that serious a public health threat, relatively speaking. So-called Differentiated Thyroid Cancer (the kind produced by radiation damage) is almost 100% curable in any modern medical system. It ain't fun, but it's not a medical catastrophe in nearly all cases. (I've had it, so speak from personal experience.)

Diablo Canyon NPP:

San Onofre NPP:

[PLAIN]http://images.ocregister.com/newsimages/undefined/2008/07/30_sanonofre1_large.jpg

 

[minerva]

This is interesting.

http://abclocal.go.com/kgo/video?id=8021906

A Zircaloy fuel cladding tube gets introduced to an oxyacetylene torch. It does not actually appear to melt or burn at that temperature.

Are any of you with better nuclear engineering expertise than me able to comment on that? Is it a myth that the Zircaloy actually "catches fire" if heated in air?

There is a lot of very good radiological data coming out of the KEK experimental physics centre in Tsukuba, outside Tokyo.

http://rcwww.kek.jp/norm/index-e.html

Above is their real-time gamma dose monitor.

They also have some very high resolution gamma spectroscopy data, showing the levels of several different significant fission products.

http://www.kek.jp/quake/radmonitor/GeMonitor2-e.html

These fission products are definitely from Fukushima, and they are there at detectable levels – but these instruments are incredibly sensitive, and these levels are absolutely harmless.

We can see the short-lived ¹³²Te dropping away readily over time, as it decays, which makes perfect sense.

We’re talking about, for example, 2 nBq (yes, nanobecquerels) of ¹³⁷Cs per cm³ of air at the moment.

Over the last week I've written a few blog posts about the Fukushima NPP incident as this has been developing. I'm sure some of you might find these posts useful or informative or interesting.

http://reindeerflotilla.wordpress.com/2011/03/19/fukushima-updates-march-18/

http://reindeerflotilla.wordpress.com/2011/03/13/all-right-its-time-to-stop-the-fukushima-hysteria/

http://reindeerflotilla.wordpress.com/2011/03/16/fukushima-redux/

I would certainly love to hear some comments, or peer-review from the more qualified nuclear engineers out there in the audience.

Would anyone care to peer-review my physics on the water loss rate in the used-fuel pool?

I'm still wondering, to be honest, why the LPCIs aren't working at Fukushima I. We know that HPCI can only run for a limited amount of time after SCRAM because there's only a limited amount of heat and steam pressure available in the nuclear steam supply system. RCIC runs on batteries during a station blackout, and those batteries only last for a finite amount of time.

But as far as I understand it, LPCI is designed to run on its own diesel-driven pumps, for days, even without station power, until the heat in the core dropped to the point where cold shutdown is reached.

Can someone explain to me why every single layer of the ECCS seems to have failed at these reactors?

 

[Astronuc]

Regarding the spent fuel pool, see -

Question about spent fuel rod cooling pools in Japàn reactor
https://www.physicsforums.com/showthread.php?t=481599

https://www.physicsforums.com/showpost.php?p=3197363&postcount=12


Zr fires are a concern at the Zr-alloy manufacturing plant - but primarily due to the fines or fine wires that could catch fire. The concern in the pool would be rapid oxidation and the deterioration of the cladding, although some raise the concern of a Zr fire. If the protective oxide cracks, it may be possible to achieve oxidation. Zr + O2 => ZrO2 is exothermic.

The questions for a SFP fire are:

1. Under what conditions does Zr or Zr alloys 'burn'?

2. Are such conditions realized with exposed Zr alloy cladding in a dry or emptied SFP?

Elsewhere I've commented about the manufacturing of Zr alloys in which hot ingots are hot worked to logs for the production of billets.