8.9 earthquake in Japan: tsunami warnings

[jtbell]

From BBC News (10:59 PM ET):

A spike in radiation levels at Japan's stricken Fukushima nuclear plant has forced workers to suspend their operation, a government spokesman says.

He was speaking after smoke was seen rising from reactor three. Earlier, a blaze struck reactor four for the second time in two days.

 

[russ_watters]

This was nice to see when I turned on my tv tonight:

 

[dlgoff]

CNN.com is reporting in a "breaking news" banner that workers at the Fukushima nuclear plant have suspended operations and evacuated.

I've heard that they returned in about 45 minutes when levels decreased.

This was nice to see when I turned on my tv tonight:

Thanks russ. I needed to hear something good.

 

[Angry Citizen]

Am I correct in assuming that, since the radiation levels are varying so dramatically, that it's unlikely the containment in any of the reactors has been breached? Wouldn't a breach indicate consistently high radiation levels? If not, what could be causing the variation?

I've heard that they returned in about 45 minutes when levels decreased.

Source.

 

[dlgoff]

Am I correct in assuming that, since the radiation levels are varying so dramatically, that it's unlikely the containment in any of the reactors has been breached? Wouldn't a breach indicate consistently high radiation levels? If not, what could be causing the variation?



Source.

I've heard that they returned in about 45 minutes when levels decreased.

I'm sorry. It was just some talk on MSNBC.

Astronuc would be better to answer your questions.

 

[russ_watters]

Man vs Mother Nature. Mother wins!

http://news.nationalgeographic.com/news/2011/03/pictures/110315-nuclear-reactor-japan-tsunami-earthquake-world-photos-meltdown/?source=link_fb20110315japan20pics

Wow, that's crazy - the 3rd picture shows a ferry boat sitting on top of a 2 story building!

 

[mugaliens]

I think it's interesting that http://photoblog.msnbc.msn.com/_news/2011/03/15/6277276-potassium-iodide-demand-spikes-in-us" .

Here's some good info:

"Kelp is a natural KI source. The iodide content can range from 89 µg/g to 8165 µg/g in Asian varieties, making prepared foods content difficult to estimate. Eating 3-5 grams of most dried, unrinsed seaweeds will provide the 100-150 micrograms iodide recommended daily allowance." - http://en.wikipedia.org/wiki/Potassium_iodide"

If you're getting your kelp from Asian sources, however, I'd recommend you pick a location upwind, and upcurrent from Japan. The 130 mg tablets, however, are sufficient to saturate the thyroid and thereby help protect, but not eliminate, radiactive iodine uptake.

The entire situation is sad indeed.

 

[DevilsAvocado]

Am I correct in assuming that, since the radiation levels are varying so dramatically, that it's unlikely the containment in any of the reactors has been breached? Wouldn't a breach indicate consistently high radiation levels? If not, what could be causing the variation?

This is what I’ve heard on NHK World and CNN:

There has been a fire in unit 4 where they store used fuel rods, this is probably causing the "variation".

750 out of 800 rescue workers have been sent away from the plant.

The authorities have increased the acceptable radiation level to 250 millisievert (I’m not 100% sure about that number because it seems very high... since this must be per hr...?). The normal level for an employee at a power plant is 50 millisievert per year.

As I understand; the main problem is that they are being hindered by the radiation to fight the "other problems"... which causes more problems ...

And there have been more aftershocks, one M6.1 ...

I really feel sorry for the Japanese people.

 

[OmCheeto]

Am I correct in assuming that, since the radiation levels are varying so dramatically, that it's unlikely the containment in any of the reactors has been breached? Wouldn't a breach indicate consistently high radiation levels? If not, what could be causing the variation?
Source.

The radiation source is obviously airborne. It's therefore obvious that radiation levels are dependent on wind direction.

Check out the boss's friend's http://park18.wakwak.com/~weather/geiger_index.html" .

There are two containment vessels. The "Reactor Vessel", good to probably a couple thousand psi, and the "Containment Vessel", good to about 200 psi. Each is vented to prevent over-pressurization. It is these venting events that are causing the spikes in radiation levels. Over-pressurization of the reactor vessel would result in catastrophic failure. ie; Chernobyl.

This reminds me somewhat of the Gulf oil spill. A world full of experts, scratching their heads trying to figure out what to do when all hell breaks loose.

 

[nismaratwork]

His wife didn't survive, that was mentioned in another article.

"Anima eius et animae omnium fidelium defunctorum per Dei misericordiam requiescant in pace." I think the worst are these mothers who's children were ripped from their grasp... not their fault, but I doubt they'll ever accept that. This is... all becoming a bit overwhelming as an observer... I can only say that the Japanese people are strong, and proud, and this won't break them.

@Russ: That's some amazing video... rescue was by the Reagan?

@mugaliens: I believe it, I talked to my friends in Hawaii, and despite relaying Astronuc's good info... they're buying iodine! *shrug* I guess everyone needs to feel some kind of power over these events.

Then again...

@DA: I'm hearing the same... and those 50 at the plant are basically accepting a shortening of their lifespan by an indeterminate period.

 

[nismaratwork]

Crud crud crud crud crud crud crud...

They withdrew the last workers from Fukishimi-Daichi... That.. as I understand it, is a very very bad sign.

 

[nismaratwork]

Whoa... CNN reported that the Japanese PM used profanity and yelled at TEPCO heads...

That's... wow. He must be beyond pissed off to do that!

I honestly expect some suicides at TEPCO.

 

[rhody]

For what it is worth...

http://www.csmonitor.com/USA/2011/0...uel-pools-and-why-are-they-a-threat/(page)/2"

Fuel rod assemblies
Each "fuel assembly," roughly 15 feet long, is a unit containing 82 fuel rods full of the reactor's fuel: uranium oxide pellets. During periodic refueling shutdowns, workers typically replace 20 to 30 percent of the fuel assemblies.

Once extracted from the reactor, the used assemblies are housed in close-fitting steel containers that are treated with boron, to ensure they don't resume the chain reactions necessary to generate electricity.

The used assemblies are then submerged in 45 feet of water in a spent-fuel pool. The water acts as a radiation barrier, in addition to serving as a coolant.

and

Spent fuel releases its most intense heat during the first 100 to 120 days after it is removed from the core, says Glenn Sjoden, a professor of nuclear engineering at Georgia Tech in Atlanta. Indeed, as workers try to cope with three reactor cores and at least four troubled spent-fuel pools, "we're looking at having to manage this heat over the next three months."

After that first few months, a fuel assembly can be removed from the pool for reprocessing, he adds.

At the stricken Fukushima I plant, much of the spent fuel in the six pools had been moved to a reprocessing facility. But No. 4's pool has a full reactor core's worth of spent fuel sitting in it – fuel withdrawn from No. 4's reactor during a routine maintenance outage that began on Nov. 30, 2010.

This gives you big picture perspective... Comments, Astro ?

Rhody...

P.S. http://quanta-gaia.org/reviews/books/FeymanJoking.html" , pay particular attention to the last 10 sections... there is a kernel of truth (IMHO of course) buried in there, one I never forgot, and wanted to share...

 

[DevilsAvocado]

Cyclones and meteor strikes?

Heavy snow, visibility 40 meters, -2 Celsius (28 Fahrenheit)

http://au.news.yahoo.com/thewest/a/-/world/9023365/snow-piles-more-misery-on-japans-devastated-northeast/"

 

[DevilsAvocado]

For what it is worth...

Thanks Rhody.

Stupid question: Is this "pool" inside unit No. 4?

 

[Astronuc]

For what it is worth...

http://www.csmonitor.com/USA/2011/0...uel-pools-and-why-are-they-a-threat/(page)/2"

I'll comment later. The fuel (UO2) height in a BWR is about 12.3-12.5 ft (146-150 inches), and there is a small void volume (plenum) at the top of the fuel rod to moderate pressure. The fuel is surrounded by Zr-2 cladding and sealed at both ends by Zr-2 endplugs. Eight of the fuel rods are special in that they attach the top and bottom tie plates which are part of the supporting structure of a BWR fuel assembly. Fuel in the 1970s used an 8x8 array of fuel rods. In the mid 1980s, 9x9 arrays were introduced, and in the 1990s, 10x10 arrays became the norm. The rods got smaller in diameter and the different arrays all occupy the same envelope.[/quote]

I know Glenn. He knows his stuff. The concern is that Unit 4 was shutdown and it appears that they did a full core offload - which mean the hottest fuel is in the SFP. The concern is that pool is the most at risk for boiling dry.

 

[nismaratwork]

That, and the concern that the cladding seems to be what was burning.

That's... what releases the cesium... right?

@DA: The fuel containment pool is above ground, but within containment, or was at least.

@Astronuc: Your friend has been on CNN, as I recall, and he was both very honest and extremely wise in his caution. Talk about a level head, and he was being constantly pestered for a doomsday scenario.

 

[rhody]

I'll comment later. The fuel (UO2) height in a BWR is about 12.3-12.5 ft (146-150 inches), and there is a small void volume (plenum) at the top of the fuel rod to moderate pressure. The fuel is surrounded by Zr-2 cladding and sealed at both ends by Zr-2 endplugs. Eight of the fuel rods are special in that they attach the top and bottom tie plates which are part of the supporting structure of a BWR fuel assembly. Fuel in the 1970s used an 8x8 array of fuel rods. In the mid 1980s, 9x9 arrays were introduced, and in the 1990s, 10x10 arrays became the norm. The rods got smaller in diameter and the different arrays all occupy the same envelope.

I know Glenn. He knows his stuff. The concern is that Unit 4 was shutdown and it appears that they did a full core offload - which mean the hottest fuel is in the SFP. The concern is that pool is the most at risk for boiling dry.

Thanks Astro...

A question, hypothetical... before the spent fuel rods are placed in the cooling pool, this sounds logical, but may be impractical due to their design, would it be possible to separate the pellet assemblies by a greater distance before being submerged, hence, not as much cooling required for the 3-4 month cool down period ?

Picture the pellet assemblies in the tube being connected to one another by a giant rubber band, and the rod being especially long on either end with a fair amount of free space, and the rubber band with the pellet assemblies protruding from either end. If you pull the rubber band from each end with the same amount of force the attached pellets now separate further, slowing their interaction and heat generated with one another. Would this decrease the temperature for cooling, and would the time to cool the rod assemblies be speeded up ?

Rhody...

 

[nismaratwork]

I know Glenn. He knows his stuff. The concern is that Unit 4 was shutdown and it appears that they did a full core offload - which mean the hottest fuel is in the SFP. The concern is that pool is the most at risk for boiling dry.

Thanks Astro...

A question, hypothetical... before the spent fuel rods are placed in the cooling pool, this sounds logical, but may be impractical due to their design, would it be possible to separate the pellet assemblies by a greater distance before being submerged, hence, not as much cooling required for the 3-4 month cool down period ?

Picture the pellet assemblies in the tube being connected to one another by a giant rubber band, and the rod being especially long on either end with a fair amount of free space, and the rubber band with the pellet assemblies protruding from either end. If you pull the rubber band from each end with the same amount of force the attached pellets now separate further, slowing their interaction and heat generated with one another. Would this decrease the temperature for cooling, and would the time to cool the rod assemblies be speeded up ?

Rhody...

Each pellet is still going to decay at the same rate AFAIK, because we're talking about decay heat, and eventual storage. Remember, they're done interacting with each other (I think) in any meaningful way, but beta decay is still ongoing, and separation would just add risk... not to mention opportunities to skim a pellet here and there for sale on the black market. That would be a nightmare, not to mention you'd be compromising the rod...

 

[Astronuc]

I know Glenn. He knows his stuff. The concern is that Unit 4 was shutdown and it appears that they did a full core offload - which mean the hottest fuel is in the SFP. The concern is that pool is the most at risk for boiling dry.

Thanks Astro...

A question, hypothetical... before the spent fuel rods are placed in the cooling pool, this sounds logical, but may be impractical due to their design, would it be possible to separate the pellet assemblies by a greater distance before being submerged, hence, not as much cooling required for the 3-4 month cool down period ?

Picture the pellet assemblies in the tube being connected to one another by a giant rubber band, and the rod being especially long on either end with a fair amount of free space, and the rubber band with the pellet assemblies protruding from either end. If you pull the rubber band from each end with the same amount of force the attached pellets now separate further, slowing their interaction and heat generated with one another. Would this decrease the temperature for cooling, and would the time to cool the rod assemblies be speeded up ?

Rhody...

It is not practical to dismantle the fuel assemblies, that is time consuming and would take up more space/volume was increased. Each BWR fuel assembly has a square channel around the fuel rods, and the channel provides good lateral support.

There was a consideration of consolidation - putting spent fuel rods in a tighter latter - but only after long cool down. As far as I know, the concept was abandoned in the mid to late 90s.

There is a axial power/burnup dependence in a fuel assembly/rod. Since the flux decreases at the edge of the core, the top power generation and burnup decrease more or less proportionally, so the decay heat generation also decreases. It is the middle 75-80% that generates the significant decay heat - and there is not much that can be done about that - except to provide cooling water.

In the SFP, one can see thermals arising from natural convection in the storage racks. There are flow holes at the bottom of the rack, and cooler water from the edge of the pool and older/cooler assemblies displaces the warmer water in the younger assemblies, so there is some cooling by natural convection.

The SFP is cooled by an external system in a 'closed' recirculation system. The heat is simply conducted to the environment.

 

[rhody]

Thanks Astronuc,

That makes perfect sense from an expert in a clear unambigious manner.

Rhody...

 

[rhody]

http://www.miamiherald.com/2011/03/16/2118120/elite-japan-nuclear-workers-race.html"

Small teams of the still-anonymous emergency workers rush in and out for 10 to 15 minutes at a time to pump sea water into the plant's overheated reactors, monitor them and clear debris from explosions. Any longer would make their exposure to radioactivity too great.

Even at normal times, workers wear coveralls, full-face masks with filters, helmets and double-layer gloves when they enter areas with a possibility of radiation exposure. Some of them carry oxygen tanks so they don't have to inhale any radioactive particles into their lungs.

and

The workers' challenges this week have included struggling for hours to open a pressure-release valve and allow water to enter the reactors. When a worker left the scene for a short period, the water flow ceased and fuel for pumps bringing up the water ran out.

A building housing a spent fuel storage pool exploded at one point, making two huge holes on the upper side of the wall on the building. A plant worker spotted a fire shortly thereafter that was later put out.

The workers also have had to walk around the area to measure radioactivity in each place they were supposed to enter, and remove contaminated debris. They also struggle with broken equipment and a lack of electricity.

"Workers persevere amid fears of 400 millisieverts," read one headline in the nationally circulated Yomiuri newspaper.

Rhody...

P.S. Just read in another article, a total of 180 workers are rotating in and out (50 or so at a time) to keep exposure to a minimum (250 millisieverts maximum lifetime exposure). At that point what do they do, bring in more people and train them who have not been exposed ?

 

[FlexGunship]

^^^^^^^^^^

[PLAIN]http://newamericangazette.com/wp-content/uploads/2011/01/fbd0bbaekhammentary.jpg

I know it's a little overly dramatic (I'm confident they are safe and avoiding unnecessary risks)... but those guys are heroes.

 

[Angry Citizen]

Totally agree. They better receive one hell of a company bonus at the end of this -- at least.

 

[nismaratwork]

Yeah, I'm not sure how overly dramatic that is... if it's just 180 people exposed around the clock, they've at LEAST shortened their lives. More likely they'll (or have) received quite an acute dose... so... yeah that works.

 

[Angry Citizen]

Power will soon be restored to the nuclear plants:

http://news.yahoo.com/s/ap/20110316/ap_on_bi_ge/as_japan_earthquake

 

[nismaratwork]

Power will soon be restored to the nuclear plants:

http://news.yahoo.com/s/ap/20110316/ap_on_bi_ge/as_japan_earthquake

I'll believe it when I see it working the appropriate systems, if they still function. TEPCO is, in my view as of this last decade... useless.

 

[FlexGunship]

I'll believe it when I see it working the appropriate systems, if they still function. TEPCO is, in my view as of this last decade... useless.

Well, I think we can agree that YOU and I have NOOOOOO idea what it means to be a TEPCO administrator/employee. I understand their history but I don't pretend to understand the context or cultural setting.

Let's keep things in perspective here, Japan got rocked with a 9.0 earthquake! If you look at the rate of occurrence, they're less than one-in-ten-thousand-years per region! Given that, things are looking pretty amazing if you ask me. This isn't the fault of the engineers that designed the place, or the operators, or the plant administrators!

Sometimes this **** happens. Let's be thankful that everyone seems to have kept a cool head and that, all things considered, the dangers of radiation contamination seems minor compared to other earthquake/tsunami-related damage.

 

[nismaratwork]

Well, I think we can agree that YOU and I have NOOOOOO idea what it means to be a TEPCO administrator/employee. I understand their history but I don't pretend to understand the context or cultural setting.

Let's keep things in perspective here, Japan got rocked with a 9.0 earthquake! If you look at the rate of occurrence, they're less than one-in-ten-thousand-years per region! Given that, things are looking pretty amazing if you ask me. This isn't the fault of the engineers that designed the place, or the operators, or the plant administrators!

Sometimes this **** happens. Let's be thankful that everyone seems to have kept a cool head and that, all things considered, the dangers of radiation contamination seems minor compared to other earthquake/tsunami-related damage.

Yeah, but I'm thinking of their last radiological release, and the PM actually losing his cool with them. Putting together the pieces of what Astronuc has said, it really sounds like TEPCO above all is on the hook here. Yes, mother nature kicked them in the balls, but this is still not acceptable.

Hell man, look at the ambient radiation in Toykyo.. almost double on average what it was before... Tokyo... not Fukishima. Let's just hope that's all gamma and not alpha emitting, or you multiply that by 20 (at LEAST) in conversion to Sieverts.

edit:
http://www.indianexpress.com/news/japan-nuclear-plant-logs-3rd-radiation-leak/206019/
http://cnic.jp/english/newsletter/nit140/nit140articles/kk.html

This is not news to TEPCO, and new info is coming out that Fukishima was asessed to be risky in this kind of event. I'm pro-nuclear, I think that's been clear, but I'm not pro-TEPCO right now.

See CNN's Atika Shubert talking about diplo-cables.

 

[Proton Soup]

I think it's interesting that http://photoblog.msnbc.msn.com/_news/2011/03/15/6277276-potassium-iodide-demand-spikes-in-us" .

Here's some good info:

"Kelp is a natural KI source. The iodide content can range from 89 µg/g to 8165 µg/g in Asian varieties, making prepared foods content difficult to estimate. Eating 3-5 grams of most dried, unrinsed seaweeds will provide the 100-150 micrograms iodide recommended daily allowance." - http://en.wikipedia.org/wiki/Potassium_iodide"

If you're getting your kelp from Asian sources, however, I'd recommend you pick a location upwind, and upcurrent from Japan. The 130 mg tablets, however, are sufficient to saturate the thyroid and thereby help protect, but not eliminate, radiactive iodine uptake.

The entire situation is sad indeed.

i don't think the japanese have anything to worry about so far as iodine is concerned. they already consume a few orders of magnitude more iodine than we do.

http://www.jpands.org/vol11no4/millerd.pdf

they eat more in a day than what is included in one of those 130mg pills. if people here feel better stocking up on iodine pills, i wouldn't think it's any concern.