Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[timeasterday]

THE CRANE DID NOT FALL ON THE ADJACENT BUILDING

The earlier report of damages that the crane had fallen from unit 3 are incorrect. I stand corrected and I am now convinced that I see the entire crane structure, under the roof girders, and over the area of the concrete plug of the primary containment of unit 3. Thanks for pointing that out.

http://i306.photobucket.com/albums/nn270/tcups/DrywellTorus.jpg

Yep, that's what I was seeing too. You can also see the same crane in shots of #4.

 

[Ms Music]

I decided to take some time today to examine the flyby video, and the drone pictures posted. It appears to me that the area with the "shiny rebar" is on the north side of the northwest corner of reactor building 3. Am I correct? (starts after 45 seconds -to 60 seconds)

http://www.youtube.com/watch?v=z9fKtXDaQVc"

Which now seems to be completely empty of rebar?

http://cryptome.org/eyeball/daiichi-npp/pict7.jpg
[/url]

People had speculated this was fresh fuel, so I assumed it would have fallen out of 4. But now it appears it came from 3? Is there any reason fresh fuel would have been in the north west portion of 3?

I know this is all speculation, but I am very confused. If it was rebar, it should still be there... It appears it has been cleaned up.

If it WAS fresh fuel, is it a hazard to workers?

Sorry if this was gone over previously, I have a tough time keeping up with this VERY busy thread. Thankful for all the people here!

 

[rmattila]

If one assumes about 10 GWd/tU assembly average burnup in each of 3 cycles and about 8 GWd/tU in the fourth, that would be in the ball park. One would have to pro-rate the current cycles.

Calculating from the power density (400 assemblies and 1380 MWth for unit 1, 548 & 2381 for unit 2), and assuming 80 % capacity factor and 170 kg U weight per assembly, one would get 5.93 MWd/kgU of exposure per year for unit 1 and 7.47 MWd/kgU for units 2&3. The rest depends on the cycle length and reload batch size.

I made a quick spreadsheet for guesstimating the core average burnup in different reload schemes. It seems that the core average burnup at unit 1 would probably lie around 20 MWd/kgU, and probably somewhat lower for the units 2&3. Any additional info on the reload strategies (=maximum discharge burnup & cycle length) would help in obtaining a better estimate. (NB: That's just a quick example to give an idea, certainly not double-checked for errors and/or omissions!)

 

[Astronuc]

Mr. Astronuc, I had my socks and shoes off trying to figure the possible amount of uranium involved while you were posting your figures so I didn't see it. Now that I see it, your attachment more than doubles my amount of known uranium involved between the 4 reactors. I understand some fuel is in various stages of decay thus less potent and I by no means what to understand the inter-workings of a nuke plant but was just trying to get a idea of the energy that could be released esp. in case of fire.

Your pic with totals seems high. Do they really have that much stored in spent fuel ponds? Did Unit 4 actually have those amount of assemblies already loaded?...At least as far as you know.

I haven't verified those number yet, but they seem reasonable. Unit 1 would have the equivalent of about 3 batches in its SFP. That means they have offloaded some (oldest assemblies) to the common pool. Units 2 and 3 seem about right. I expect they have plans to offload some of the oldest fuel. Each pool probably has 3 to 4 batches of old fuel. The oldest batches would probably have been cooled down over about 3+ years.

Unit 4 did a full core offload for maintenance. They would then reinsert some fuel (2 or 3 batches) and add fresh fuel (some or all of the 200). If the unit is loading ~1/3 core, that's about 180 assemblies. They may have a policy of keeping some extras just in case. On the other hand, depending on capacity factor and cycle length, they could be doing reloads of up to 200 assemblies in Units 2, 3 and 4.

 

[razzz]

Unit 4 has 1331 in SFP plus 200 newly delivered brand new units - reactor is unloaded
I also included my earlier post which estimate the heat load

Thanks for that (again) AntonL. I'm sure you'll correct me if I'm wrong in the following...

Doesn't seem possible, now I come up with about 854 tons of uranium between the 3 reactors and 4 pools. And 'fuel elements' I take to mean 'assemblies' where 60 fuel rods makeup 1 assembly and one assembly contains an estimated .171 ton of uranium with 4995 assemblies in play or 299,640 individual fuel rods. Crazy.

I can see why the US sent specially trained Marines for population decontamination.

Nothing has blown up lately, which is about the only good thing.

 

[TCups]

I know this is all speculation, but I am very confused. If it was rebar, it should still be there... It appears it has been cleaned up.

If it WAS fresh fuel, is it a hazard to workers?

Sorry if this was gone over previously, I have a tough time keeping up with this VERY busy thread. Thankful for all the people here!

It still appears to be there, in the NW corner of Bldg 3

It is uncertain what the rod-like structures are.

It is unlikely spent fuel (or fresh fuel rods) would have been transferred to the equipment pool. The fuel handling machine does not go there and I don't think there is a transfer chute that would allow the fuel rods to be transferred under water to the equipment pool. The equipment pool contains the head of the pressure vessel when the reactor is shut down and the reactor pressure vessel is opened for refueling. Perhaps someone can confirm that statement.

 

[jensjakob]

Gents,

At some time we discussed how high the Tsunami had swept at Fukushima.

Looking at the hi.res images I found these tanks on the west-side of #4. See the pond around them? Full of water.

I checked with some of the early video from the plant, before water-spraying, and they are also full on those videos.

I vote for this as an indication that a pretty powerfull wave swept past all reactors.

Still searching for more signs in the images.

/Jens Jakob

 

[james14]

We have heard many times that the radiation coming from the standing water is > 1000 mSv / hr. So we don't know the actual levels, just that it's greater than the 1000. I believe some here have estimated this value to be wildly lower than the actual.

Lately there have been reports of this water being > 10,000 times the level of water normally in a reactor.

Would I be right therefore in assuming that the normal level of radiation levels of water in a reactor is approx 0.1 mSv / hr?

Basically I was wondering if the "levels > 10,000" was as limited a piece of information as the "> 1000 mSv/hr" one. Or, if we could perhaps work out an actual level of radiation from those figures of "> 10,000 times the normal level in a reactor"

 

[timeasterday]

I don't think this image has been posted before but seems to show refueling operations at one of the reactors.

 

[shadowncs]

Still searching for more signs in the images.

We can only speculate but look at aerial-2011-3-30-0-50-45.jpg from 20 March... if those are tsunami runups then we have an idea.

 

[Demidrol]

I don't think this image has been posted before but seems to show refueling operations at one of the reactors.

And in what is known?

 

[razzz]

We can only speculate but look at aerial-2011-3-30-0-50-45.jpg from 20 March... if those are tsunami runups then we have an idea.

Google Earth shows elevation where ever you point the mouse.

 

[jensjakob]

Here is another crop of the northside of #3.

I am as sure as I can be, that the side was blasted out - and my best shot is that the blast originated from the equipment pool.

 

[83729780]

We have heard many times that the radiation coming from the standing water is > 1000 mSv / hr. So we don't know the actual levels, just that it's greater than the 1000. I believe some here have estimated this value to be wildly lower than the actual.

Lately there have been reports of this water being > 10,000 times the level of water normally in a reactor.

Would I be right therefore in assuming that the normal level of radiation levels of water in a reactor is approx 0.1 mSv / hr?

Basically I was wondering if the "levels > 10,000" was as limited a piece of information as the "> 1000 mSv/hr" one. Or, if we could perhaps work out an actual level of radiation from those figures of "> 10,000 times the normal level in a reactor"

the multiplier references radioactivity (becquerels), not radiation

there's also a need to distinguish "times normal level" from "times legal limit"

also, the >1,000 mSv/hr was a measurement taken a couple of days ago from water in the turbine building of reactor 2. The most recent measurement of "10,000 times the legal limit" was a becquerel measurement from water near reactor 1 (see AntonL's post on the previous page [https://www.physicsforums.com/showpost.php?p=3221570&postcount=2251"])

 

[jensjakob]

I don't think this image has been posted before but seems to show refueling operations at one of the reactors.

Leads to some very interesting questions:
1. The refueling machine has narrower width than reactor opening. (Which is square).
2. Does this mean that fuel only can be stored in the SPF pool, since the refueling machine can't move to the other side of the reactor?
3. Can the "crane" turn around and operate on the other side (e.g. if there were tracks in the reactor concrete lid so the refueling machine could be restationed to the other side?)

Curios
Jens Jakob

 

[jlduh]

Ms Music: I double checked and you are right on one thing: the supposed fuel rods on the roof was a place at No3 reactor, and not No4 as previously stated.

But I think the resolution on the Hi res picture is still not sufficient to see such small sticks. I did a capture that puts precisely right in the middle the place where the supposedly "fuel rods" are seen on the video, it was close to these green spots. The rebar was more on the lower left side of my screenshot.

http://www.netimago.com/image_184819.html

To me it is impossible to decide if they are there or not. But i confirm that this would be a strange place to be for a fuel rod as the SPF is on the other side.

 

[TCups]

I don't think this image has been posted before but seems to show refueling operations at one of the reactors.

Very helpful.

The approximate size and relative location of the refueling chute in the SFP is apparent.

We know that this building has the concrete superstructure, like Bldgs 3, 4.

We know that the yellow dome to the left is the drywell cap.

Does anyone know what is sitting in the corner behind the drywell cap?

 

[jlduh]

Unit 4 did a full core offload for maintenance

Astronuc, can you confirm that it was stopped for full maintenance with all the fuel rods outside of the core?

EDIT: Well i checked the IRSN reports they say the core was unloaded so i guess it was and you are right.

If that's the case (I missed the detail, i just noted that it was shut down for maintenance which i interpreted -probably wrongly- as fuel maintenance) then my post below is irrelevant (still the destructions to Building 4 are impressive if we consider only an H2 explosion from the top floor and the SFP... It's pity we didn't have any video from this or these explosion(s)

https://www.physicsforums.com/showpost.php?p=3221404&postcount=2226

 

[james14]

the multiplier references radioactivity (becquerels), not radiation

there's also a need to distinguish "times normal level" from "times legal limit"

also, the >1,000 mSv/hr was a measurement taken a couple of days ago from water in the turbine building of reactor 2. The most recent measurement of "10,000 times the legal limit" was a becquerel measurement from water near reactor 1 (see AntonL's post on the previous page [https://www.physicsforums.com/showpost.php?p=3221570&postcount=2251"])

Thanks for that, its a distinction that I didn't understand at all.

I assume there is at least some connection? IE an increase in the level of radioactivity (becquerels) would normally result in a higher dose of radiation (sieverts)?

And if so, is it possible to estimate one from another, or is it just not feasable?

Thanks again!

 

[shadowncs]

Google Earth shows elevation where ever you point the mouse.

Yes, that would be the hill behind the plant and if those are runups then the tsunami left the mark on those hills. Look at the left marks that cross a road going downhill at an angle. If they're not runups I don't know what they are.

 

[Illbilly]

Very helpful.

The approximate size and relative location of the refueling chute in the SFP is apparent.

We know that this building has the concrete superstructure, like Bldgs 3, 4.

We know that the yellow dome to the left is the drywell cap.

Does anyone know what is sitting in the corner behind the drywell cap?

Could it be the fuel elevator?

 

[Ms Music]

Sorry, I guess this WAS being debated recently.

It still appears to be there, in the NW corner of Bldg 3

.

You are right that what the helicopter is focusing on in seconds 54 to 58 is still there, but what they appear to focus on during seconds 50 to 53 appears to be gone, but I will just pass it off to poor resolution images.

Fuel rods definitely does not make sense to be in that area.

I just hope they can get things under control soon. I feel terrible for all workers involved, and all the people in the region affected.

 

[PietKuip]

As a former NPP manager, I've been closely following this event from the beginning, but just found this forum yesterday. I've been trying to put myself in their shoes to better understand what they are dealing with.
I would fully expect that they are doing their best to limit doses to workers ALARA - even in these very stressful circumstances. They would not be irresponsibly simply ordering someone to go and get a sample. They would do their best to use long handled sampling, different routes etc and HP briefings to minimize dose.

Now we hear how irresponsible Tepco is: they had not even brought in sufficient numners of personal dosimeters for the people working there. It is disgusting.

 

[jinxdone]

I ran into a video clip from a camera mounted to the boom of a crane used to pump water into the SFP of reactor building 4.

http://www.ustream.tv/recorded/13684184

On the clip the view is mostly obscured either by roof structures or billowing smoke/steam. Here's a few images where the smoke is out of the way.

I assume this was taken from the same red crane that is visible in the recent aerial images.

[URL]http://i.telegraph.co.uk/multimedia/archive/01861/fukushima-aerial_1861606c.jpg[/URL]

*PS Take a look at the video yourself to get a better idea where the smoke or steam is originating from

 

[Borek]

Now we hear how irresponsible Tepco is: they had not even brought in sufficient numners of personal dosimeters for the people working there. It is disgusting.

To quote earlier post from the same thread:

Do not condemn until you have walked in their shoes.

 

[hbjon]

Yes. A steam explosion can occur without air being present:
http://en.wikipedia.org/wiki/Steam_explosion"

And at high enough temperature (>1700 Celsius) zirconium also reacts explosively with steam producing hydrogen without the need for air.
Zr + 2H2O -> ZrO2 + 2H2

Of course once hydrogen escapes the containment it can also explode in air.

Any danger of the H-2 fusing together? Or at the current temp and pressure this not possible?

 

[Astronuc]

Any danger of the H-2 fusing together? Or at the current temp and pressure this not possible?

No. The only concern about hydrogen is deflagration or detonation. Beyond that, the concern is the degraded condition of the fuel, which no longer confines the fission products. Beyond that is the degraded condition of the reactor coolant system which provides the next barrier between fission products and the environment. Beyond that is the degraded condition of the containment system which is the third barrier between fission products and the environment.

Proton fusion has a relatively low probability even in the center of the sun with a density of 160 g/cm³, 10 times that of lead, or 160 times that of water at 1 atm and ~25°C. The sun's core temperature of 15 million K (27 million °F) keeps it in a plasma state.

Ref: http://fusedweb.pppl.gov/cpep/chart_pages/5.plasmas/sunlayers.html
http://hyperphysics.phy-astr.gsu.edu/hbase/astro/solarpp.html
http://csep10.phys.utk.edu/astr162/lect/energy/ppchain.html (On average it takes about 10⁹ years for a proton to fuse with another proton! That's why the sun is around so long.)

Normal condition in the BWR core is a mix of saturated liquid water and steam at ~286°C, with the cladding temperatures a bit hotter, and the fuel temperatures of 350-1400°C, where the highest temperature of the fuel is the centerline. In the current situation, the fuel temperature is much low, probably on the order of 200-400°C.

 

[sigyn]

Any danger of the H-2 fusing together? Or at the current temp and pressure this not possible?

No possibility of fusion.

 

[gmax137]

That looks like a bunch of 3/8 inch stainless tubing to me. There's typically miles of that stuff in a plant, used for instrumentation.

It does not to me.

I see rumpled elongated narrow sheets that were made that way by physical shock, like from that explosion.
They appear to be (approximate guess) ten times to fifteen times wider than they are thick.
For them to have taken on such a rumpled shape their substance must have some malleability, much like lead.
What ever fits that description is what it is.

I think they are fuel rods that have been through one hell of an explosion.


But what the hell, I am not a nuclear engineer. I just go by what my eyes tell me.

...

"a thing's a phallic symbol if it's longer than it's wide" -- Melanie

 

[hbjon]

No. The only concern about hydrogen is deflagration or detonation. Beyond that, the concern is the degraded condition of the fuel, which no longer confines the fission products. Beyond that is the degraded condition of the reactor coolant system which provides the next barrier between fission products and the environment. Beyond that is the degraded condition of the containment system which is the third barrier between fission products and the environment.

Proton fusion has a relatively low probability even in the center of the sun with a density of 160 g/cm³, 10 times that of lead, or 160 times that of water at 1 atm and ~25°C. The sun's core temperature of 15 million K (27 million °F) keeps it in a plasma state.

Normal condition in the BWR core is a mix of saturated liquid water and steam at ~286°C, with the cladding temperatures a bit hotter, and the fuel temperatures of 350-1400°C, where the highest temperature of the fuel is the centerline. In the current situation, the fuel temperature is much low, probably on the order of 200-400°C.

Oh geez, wow did I misspeak. Thanks astronuc, Your the bomb.

 

[Bez999]

Leads to some very interesting questions:
1. The refueling machine has narrower width than reactor opening. (Which is square).
2. Does this mean that fuel only can be stored in the SPF pool, since the refueling machine can't move to the other side of the reactor?
3. Can the "crane" turn around and operate on the other side (e.g. if there were tracks in the reactor concrete lid so the refueling machine could be restationed to the other side?)

Curios
Jens Jakob

Look again Jens, it appears this photo was taken from the SFP, with the machine standing over the reactor vessel. It looks like the perspective has you fooled, you can see the machine bridge tracks on the other side of the pool there.

 

[hidsuz]

Hi folks. Here in Tokyo and need to make a decision in the next few days. Stay and work but incur moving costs without knowing whether I`ll still end up having to leave, or simply quitting and starting from scratch back home. TEPCO, the govt, media, agenda based 'experts' simply cannot be trusted. Been reading this most excellent forum and, if I could oblige( I can start a different thread or try elsewhere if this is too OT), have some questions.

1)What is the worst case scenario?
2)What is most probable?
*and on what time frame to both

If I will most likely have to deal with ongoing radioactivity fears of the air, food, water and potential explosions on a day to day basis for years instead of months, it`d be an easy decision to leave. Thanks, I will try to provide any real time news.

 

[83729780]

I assume there is at least some connection? IE an increase in the level of radioactivity (becquerels) would normally result in a higher dose of radiation (sieverts)?

And if so, is it possible to estimate one from another, or is it just not feasable?

http://hps.org/publicinformation/ate/faqs/gammaandexposure.html" (with formulas)

http://www.radprocalculator.com/Gamma.aspx" (online calculator)

 

[TCups]

Look again Jens, it appears this photo was taken from the SFP, with the machine standing over the reactor vessel. It looks like the perspective has you fooled, you can see the machine bridge tracks on the other side of the pool there.

@Bez999

It looks to me like the fuel rods are in the chute, not the reactor. The lovely blue of the cherenkov radiation doesn't seem to open up any wider than the chute. The gates on the chute to both the SFP and the drywell containment are open, else I don't think you would see the blue color.

I can see what may be the rail for the fuel handling machine on the left extending back as far as the back of the chute, and presumably the opening over the reactor's core, but I cannot say it extends further.

The best diagrams I have do not show the rails for the fuel handling equipment extending over the equipment pool. Neither do I see any indication on the diagram for a chute between the back side of the drywell containment and the equipment pool.

http://i306.photobucket.com/albums/nn270/tcups/Oyster-Creek-reactor.gif

My understanding is that the equipment pool is used for storage of the reactor vessel cap (not the drywell cap) during the refueling process. It has been suggested to me by Astronuc the equipment on the floor at the back left corner might be the steam dryer (would that be radioactive?).

 

[razzz]

hidsuz: I'd start with a extended vacation starting immediately until they get some kind of control over the situation.

Drudge Report has a bunch of headlines up concerning the nuke situation, like...
http://chronicle.augusta.com/latest-news/2011-03-31/srs-concrete-pump-heading-japan-nuclear-site"

I'd say a 7.0 or larger quake and these boom trucks are toast if set up.