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Friday, March 11, 2011

It's Beyond Bad

Update: There is a major containment failure, but Japanese authorities were told that the outside container is intact, so I think we can take it for granted that the reactor is ruptured. I ain't worrying for nothing. The evacuation area is being expanded. Neil's video:

End update.

If you pray, pray for them in Japan. If you don't, now is the time to start.

They're in terrible trouble. Tepco News. At a minimum, it looks like they'll have to vent multiple times now.

Note: both of the plants in immediate crisis are in Fukishima and the company is Tokyo. Note the ages in the right column for Daini and Daiichi. They need to get those internal pressures down very quickly. Temps at at least one are well past boiling.

(This is why I am skeptical of keeping plants in operation after 30 years.) What seems to have happened is that they went through the earthquake but then the backup generators flooded out. Pics of plants. The one reported currently in the worst shape is from the 70s, I think.

I can't even type right. I keep having to fix this post. I got very little sleep last night, and I've been twitching all day over their situation. Imagine what shape they are in.

Note: if you are wondering what this is all about, here is a completely unrelated incident report from two years ago, with a helpful diagram.

Note: This is the last TEPCO press release (10 AM their time):
[Nuclear Power Station]
Fukushima Daiichi Nuclear Power Station:
Units 1 to 3: shutdown due to earthquake
Units 4 to 6: outage due to regular inspection
* The national government has instructed evacuation for those local
residents within 10km radius of the periphery.
* Measurement of radioactive material (Iodine, etc.) by monitoring car
indicates increasing value compared to normal level. One of the
monitoring posts is also indicating higher than normal level. We will
continue monitoring discharge of radioactive material from exhaust stack
and discharge canal, etc.
* Considering the increasing pressure with in the reactor containment
vessel of Unit 1, the national government has instructed us to
implement measures to reduce the pressure of the reactor containment
vessel (partial discharge of air containing radioactive materials) in
order to fully secure safety.

Fukushima Daini Nuclear Power Station:
Units 1 to 4: shutdown due to earthquake
* The national government has instructed evacuation for those local
residents within 3km radius of the periphery and indoor standby for those
local residents between 3km and 10km radius of the periphery.
* At present, we have decided to prepare implementing measures to reduce
the pressure of the reactor containment vessel (partial discharge of air
containing radioactive materials) in order to fully secure safety.
These measures are considered to be implemented in Units 1 to 4 and
accordingly, we have reported and/or noticed the government agencies
concerned.
It appears that at least one person is dead at Daiichi. I don't know if they found the second missing one. It sounds almost as if they are working with robots inside Daiichi the way some of it was worded.

It sounds like the cascade into real trouble has begun at Daiichi. They couldn't vent because they got too high a radiation level. Time to scrag it. According to Kyodo News, NISA says they detected cesium at the Daiichi plant. Also a recent report says that radiation levels are now 70 times normal at the gate, whereas earlier 8 times normal was reported. This is not improving. They may be working with robots inside, because at this point I don't see how they can send humans in.

Neil showed up in the comments:
Latest official news from TEPCO re Daiichi:
All 6 units of Fukushima Daiichi Nuclear Power Station have been shut down.

Unit 1(Shut down)
- Reactor has been shut down and steam in reactor has been cooled by
isolation condenser, but it is now stopped. Because pressure level in
reactor containment vessel is increasing, following the national
government instruction, we are implementing a measure to reduce the
pressure of the reactor containment vessels in order to fully secure
safety.
Reactor water level is decreasing, we will continue injecting water step
by step.

Unit 2(Shut down)
- Reactor has been shut down and we continue injecting water by Reactor
Core Isolation Cooling System. Current reactor water level is lower than
normal level, but the water level is steady. Following the national
government instruction, we are preparing to implement a measure to reduce
the pressure of the reactor containment vessels in order to fully secure
safety.

Unit 3(Shut down)
- Reactor has been shut down and we continue injecting water by Reactor
Core Isolation Cooling System. Following the national government
instruction, we are preparing to implement a measure to reduce the
pressure of the reactor containment vessels in order to fully secure
safety.
- Currently, we do not believe there is any reactor coolant leakage inside
the reactor containment vessel.

Unit 4 (shut down due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
the reactor containment vessel.

Unit 5 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
the reactor containment vessel.

Unit 6 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant to
ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage inside
the reactor containment vessel.

We are implementing a measure to reduce the pressure of the reactor
containment vessels,
but, one of our employees working in the Unit 1 was irradiated at over
100mSv level(106.3mSv). Because of absence of industrial physician, so he
will be diagnosed at a later day.

We measured radioactive materials inside of the nuclear power station area
(outdoor) by monitoring car and confirmed that radioactive materials level
is higher than ordinary level. Also, the level at monitoring post is higher
than ordinary level.

We will continue to monitor in detail the possibility of radioactive
material being discharged from exhaust stack or discharge canal.

The national government has instructed evacuation for those local residents
within 10km radius of the periphery because it's possible that radioactive
materials are discharged.

Two workers of a cooperative firm were injured in the nuclear power station
premise. One with a broken bone was transported to the hospital by an
ambulance and the other by a company car.
Also, one of our employees could not stand up holding his left chest, so
was transported to the hospital by an ambulance
Further, there are 2 TEPCO employees whose presence has not been confirmed.
In addition, one subcontract worker standing near important earth
quake-proof building was unconscious and transported to the hospital by an
ambulance.

We are presently checking on the site situation of each plant while keeping
the situation of aftershock and Tsunami in mind.

There is a breaking news release at Kyodo News saying that they have successfully released pressure from Daiichi number 1. According to Neil (who unlike me, probably knows what he is talking about), this is an old-style reactor with a drop function so it kind of has auto shutdown. Long story, see comments.

Comments:
Wow, hard to fathom the destruction.
How can you plan for such a disaster ?
Sporkfed
 
You do because you must. There's several different layers of protection. There's the normal electricity-fueled cooling system. Then there are the backup generators which are diesel fueled. Those got swamped by the huge flood. Apparently the generators were placed far higher than any previous tsunami, but, well. Then there is the convection system, which is battery operated and only buys you a few hours until you can get backup generator capacity again.

Finally, you can use that "coolant" Hillary was talking about, which is not really a coolant. It's a mostly liquid compound with tiny suspended beads of compounds. When it is pumped into the reactor, the little plastic beads basically stick to the surfaces, the plastic kind of melts, and the compounds form a barrier and shut down the reaction.

But that's a last resort, because I think once you do that the reactor is permanently gone and can never be restarted.

It's just so huge a disaster. Normally they would have had substitute backup diesel generators already in place. Maybe they do but they have just lost too much ground. And maybe conditions are such that they have difficulty getting in there now.

They are going to have to deal with Daiichi tonight, even if they have to permanently scrag at least one reactor. The question is if they have enough of the stuff on hand, I guess.

I don't understand why they haven't vented at Daiichi yet, and they haven't, according to the last Tepco statement:
http://www.tepco.co.jp/en/press/corp-com/release/11031216-e.html

These are boiling water reactors. They're not going to produce a Chernobyl-like situation regardless. But you definitely don't want the reported pressures to go on in reactors this old.

Meanwhile, there are millions of people with no power, millions of people without food or fresh water, and probably tens of thousands of victims waiting for rescue. I saw earlier an article about a flyover of one hospital with people on the roof asking for food. With areas of devastation so hugely spread, the logistics of getting equipment in and proceeding with rescue efforts are tremendously difficult.
 
OK, some knowledgeable people posting at that Reuters link.

Sounds like one of the Fukushima plants (Daiichi?) is a very old design from the 60's, with weaker containment shell than is used in modern plants. Apparently, when the power went out the water level in Reactor #1 dropped, possibly allowing some fuel to melt and preventing a normal emergency shutdown. They've detected cesium, which comes from melted fuel rods. There is a possibility of a complete meltdown, but that doesn't mean a containment breach. The weaker containment means that they'll have to vent some gasses from inside it to keep the pressure within reasonable parameters.

Shoot, info's coming too fast for me to type. They've aborted the venting process, because the air/steam/whatever is too contaminated. Reactor #1 is melting down as I type. It's up to the containment shell now.
 
Keep your fingers crossed. This style of nuke plant has the reactor pressure vessel essentially suspended over a pool of water inside the containment vessel. If they can't stop the reaction, and the fuel melts and breaches the pressure vessel, it will drop into the suppression pool, where it will cool (producing a large amount of steam). The containment vessel contains the steam released in the process.

If it wasn't damaged by the earthquake and tsunami, anyway. It's probably fine, but keep your fingers crossed.
 
Neil - Look at this incident report from 2009. It is on the same unit.

Is that the type of reactor that you are describing? I thought these ones were different.

Your explanation, though, would explain why the water level inside the containment vessel for Number 1 keeps dropping and they are having to pump more in. It would also explain why radiation levels are high, because they shouldn't be in the containment vessel. However if the reactor breached, yeah. An earlier report cited two workers missing and three injured at Daiichi, but the three injuries were noted to be physical not from radiation poisoning.
 
That incident report is not only the same design, it's precisely the same reactor. Thanks for that, I hadn't gotten a good picture of the "upside-down light bulb" design. Just to be clear, that incident was a minor glitch in the turbine start-up, and has nothing to do with this one other than it's the same reactor.

I don't think they're pumping water into the containment vessel, I think they were pumping it into the reactor pressure vessel--trying to keep the fuel rods under water. I say were, because Reuters is now reporting an explosion at Daiichi. Bloody h**l. Pray for the engineers.
 
Reuters reports the outer building housing Reactor #1 is blown apart. Best guess is that the fuel rods dropped into the suppression chambers and caused a steam explosion. When a large mass of water flash-boils to steam all at once, it's thermodynamically a very different thing from your usual high-pressure containment failure. Containment vessel failed. Outer building failed. Molten fuel sprays everywhere, I guess. I sure hope I'm wrong.

Bloody h##l.
 
Here's video of the explosion:

http://www.youtube.com/watch?v=pg4uogOEUrU

Some outlet or another is reporting that they were using hydrogen to cool the reactor, and the H2 is what exploded. I'd kind of believe that, because of the puff of red-orange flame at the onset of the explosion. But I'm not sure it makes much difference whether it was a steam explosion or a H2 explosion.
 
Just so ya know, TEPCO's statement about the status of Daiichi Reactor #2 is ambiguous as to whether the reactor vessel is leaking. Hopefully the explosion in #1 does not disrupt the process of supplying coolant water to #2.

Meanwhile, over at Fukushima Daini, Reactors #1, #2, and #4 report that the temperature of their suppression pools have exceeded 100C. Meaning they've boiled off. They're venting those three reactors now. Hope it goes better than Daiichi #1. I'm sick of watching this train wreck.
 
Neil - I noticed that which is why I bolded it.

Also that the Tokyo Electric officials are insisting that the outside containment envelope on 1 is intact.

Your guess about the hydrogen might be right. They're replaying the clip; the original jet out is ambiguous.
 
The hydrogen arises after the nuclear fuel assembly is uncovered and gets much hotter than it should. When water (vapor?) comes in contact with the hot metal, it disassociates into molecular hydrogen and oxygen.
 
NJCommuter - thanks. TEPCO now says it was a hydrogen explosion.
 
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