CNN An 8.8-magnitude earthquake has struck Japan

[Swing low, sweet chariot. Comin' for to carry me home.]

So, Tepco is really good at covering up the "accident" (everything's under control) ...

yo, you do realize that is a cooling tower in your sig, and doesn't necessarily have anything to do with nuclear power generation?

[Tender Branson]

So, Tepco is really good at covering up the "accident" (everything's under control) ...

yo, you do realize that is a cooling tower in your sig, and doesn't necessarily have anything to do with nuclear power generation?

Of course, but the skull wouldn't look that good on a small reactor chimney ...

[Beet]

NHK now reporting that the No. 2 reactor vessel has lost all coolant as of 1:25 PM Japan time, Monday, March 14, and that pressure inside the vessel is rising. Color me baffled. I've been accused of being overly alarmed, but even I believed that after approximately 72 hours of cooling after reactor shutdown, the core would be shut down and cooled and further failure of cooling systems would not create a problem.

Apparently I was wrong.

I was too optimistic.

But I still don't understand the true situation. There is an additional plant also at risk so it behooves to know-- how many hours pass before it is safe to turn off the cooling system? And does the fact that the cooling system was running for about 72 hours at least mitigate the temperatures inside and reduce the severity of any potential meltdown?

[Queen Mum Inks.LWC]

NHK now reporting that the No. 2 reactor vessel has lost all coolant as of 1:25 PM Japan time, Monday, March 14, and that pressure inside the vessel is rising. Color me baffled. I've been accused of being overly alarmed, but even I believed that after approximately 72 hours of cooling after reactor shutdown, the core would be shut down and cooled and further failure of cooling systems would not create a problem.

What was the level of the temperature of the coolant?  Was the coolant system compromised?  And if it lost coolant, there must be a leak somewhere, which would mean a difference in the pressure.  If the the system was shutdown, but not at a cold shutdown, then a loss of pressurization could bring the system back to criticality.

[Beet]

NHK now reporting that the No. 2 reactor vessel has lost all coolant as of 1:25 PM Japan time, Monday, March 14, and that pressure inside the vessel is rising. Color me baffled. I've been accused of being overly alarmed, but even I believed that after approximately 72 hours of cooling after reactor shutdown, the core would be shut down and cooled and further failure of cooling systems would not create a problem.

What was the level of the temperature of the coolant?  Was the coolant system compromised?  And if it lost coolant, there must be a leak somewhere, which would mean a difference in the pressure.  If the the system was shutdown, but not at a cold shutdown, then a loss of pressurization could bring the system back to criticality.

None of the details have been reporting yet, as I can see. All we have is the latest IAEA report from March 14, which, between the 4 active reactors at Daiini and 3 at Daiichi, it seems only 1 Daiini reactor has achieved a cold shutdown.

[Fmr President & Senator Polnut]

http://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-worried-about-japans-nuclear-reactors/

[Queen Mum Inks.LWC]

NHK now reporting that the No. 2 reactor vessel has lost all coolant as of 1:25 PM Japan time, Monday, March 14, and that pressure inside the vessel is rising. Color me baffled. I've been accused of being overly alarmed, but even I believed that after approximately 72 hours of cooling after reactor shutdown, the core would be shut down and cooled and further failure of cooling systems would not create a problem.

What was the level of the temperature of the coolant?  Was the coolant system compromised?  And if it lost coolant, there must be a leak somewhere, which would mean a difference in the pressure.  If the the system was shutdown, but not at a cold shutdown, then a loss of pressurization could bring the system back to criticality.

None of the details have been reporting yet, as I can see. All we have is the latest IAEA report from March 14, which, between the 4 active reactors at Daiini and 3 at Daiichi, it seems only 1 Daiini reactor has achieved a cold shutdown.

Hmm... if it LOST coolant, then clearly something isn't pressurized right (and that in and of itself would effect the coolant's ability to cool, so the entire time it was supposed to be cooling the reactor, it would be less and less effective).

Out of curiosity, what exactly do you do for a living... I've done a lot of reading on nuclear power just out of curiosity, but you seem like you really know your stuff.

[Beet]

I don't do anything related to nuclear power for a living. I've been getting all my information from news reports. Right now it appears the crisis in reactor No. 3 -- the one with MOX/plutonium, is getting worse and worse.

Link

Japanese officials released no new information overnight about the Fukushima situation. But a foreign observer briefed on the situation early Monday said reactor No. 3 remained critical.

"The fuel is getting hotter and hotter," this person said.

The more of the fuel that is exposed, the hotter the fuel gets, converting even more of the coolant into steam, and worsening the situation, by exposing even more fuel to the melting and heating process, this person said. He described the crisis as proceeding like a freight train, that gathers momentum as the crisis continues.

...

The fuel rods are now "fused" together. And it appears from Bloomberg they have only 1 pump between the 3 reactors, so when the No. 2 problems started, they had to stop injecting water into No. 1 and No. 3 to reduce the temperature on No. 2.

[J. J.]

Fox:  Three reactors likely in meltdown.

Rods exposed and possibly melting.  No containment breach as of yet.

[exopolitician]

Fox:  Three reactors likely in meltdown.

Goddamn.

[J. J.]

Fox:  Three reactors likely in meltdown.

Goddamn.

Fukushimaed.

[J. J.]

September 1, 2001 to September 1, 2011.  It has been an interesting decade.

[Beet]

No. 2 is now fully exposed again. No. 3 the rods have fused together, the valves have stopped working.

I think we are looking at a full meltdown of at least 2 plants, possibly all 3 plants.

[J. J.]

No. 2 is now fully exposed again. No. 3 the rods have fused together, the valves have stopped working.

I think we are looking at a full meltdown of at least 2 plants, possibly all 3 plants.

Probably, however, there may not be major radiation leakage, but I would suspect some contamination.  The Reagan had to be moved because of low level radiation.  


They are pouring seawater on all three.  The aftershocks are causing some disruption.

[Beet]

No. 2 is now fully exposed again. No. 3 the rods have fused together, the valves have stopped working.

I think we are looking at a full meltdown of at least 2 plants, possibly all 3 plants.

Probably, however, there may not be major radiation leakage, but I would suspect some contamination.  The Reagan had to be moved because of low level radiation.  


They are pouring seawater on all three.  The aftershocks are causing some disruption.

If there is a full meltdown, it's not the stuff Fox is reporting above which has been reported all weekend. It's qualitatively different from a partial meltdown. From the experts I'm reading the molten rods will melt through the bottom of the containment. When that happens, the radioactive release could be greater than Chernobyl. I've yet to see a full explication on the media of what the consequences of that would be.

They're not pouring seawater on all three, they're only pouring seawater one at a time, because apparently there were five pumps and four were damaged. So it's 1 pump for 3 reactors. That may account for why the water levels keep going up and down, up and down. With this kind of fight, it's not clear that the 1 pump will be able to cool down all 3 reactors faster than the boiling water level falls & increases the temperature more.

Further, it's not even clear that the pump is working. The meter that should tell them what the water level is, is malfunctioning. They're also having problems with the valves that release the pressure from the boiled water. If that pressure can't be released, water can't be forced into the reactor because the pressure is too high.

What really they need to do is to restore power to the plant so that the regular cooling system can get back online. Apparently the control room where power is hooked up is flooded, they need to pump the water out of the control room and try to fix it. I assume they're working on it, but there have been no news reports.

[J. J.]

Tell me, if a core expands, would that slow or stop the reaction?

[True Federalist (진정한 연방 주의자)]

http://www.nytimes.com/2011/03/14/world/asia/14plume.html

Don't know if that's been posted but...

You must be logged in to read this quote.

Okay, so around 0.2mSv/h.  Not an amount one would want to deal with on a long term basis, but based on what has been said about what is happening almost all of the radioactivity being released is from short lived isotopes.

Still, what is happening here will be Exhibits A, B, and C for why the newest reactor designs don't require power be available for pumping to cool the reactor.  If sanity prevails in the wake of this, we'll see an increase in new reactors being built to allow for the older ones to be retired sooner.

[J. J.]

Here is the original safety precautions:  http://www.ornl.gov/info/reporter/no19/scram.htm

[True Federalist (진정한 연방 주의자)]

http://morgsatlarge.wordpress.com/2011/03/13/why-i-am-not-worried-about-japans-nuclear-reactors/

While not relevant to what is for obvious reasons our main concern, he is underestimating the impact of the loss of generating capacity.  Uniquely among developed countries, Japan does not have one electrical system, but two.  (Yes, the US has three grids, but they all use the same voltages and frequencies.)  Western Japan uses 60Hz electricity but eastern Japan uses 50 Hz electricity.  (The difference is due to the fact that when Japan first electrified, the companies in the west imported their equipment from Germany, while those in the east got theirs from the United States.  In short, the areas of Japan that get their electricity from the 50Hz grid, are not going to be able to draw much if any power from the 60Hz grid, at least not anytime soon.

It is possible to do an interconnect between AC systems that operate on different frequencies, but it is not as simple as splicing some wires, and I really doubt that whatever interconnections as do exist were designed to provide a sustained one way flow at anywhere near the level that would be needed.

[Beet]

A senior nuclear industry executive has told the New York Times that Japanese nuclear power industry managers are "basically in a full-scale panic". The executive is not involved in managing the response to the reactors' difficulties but has many contacts in Japan. "They're in total disarray, they don't know what to do," the executive added.

Radiation readings in Ibaraki prefecture between Fukushima and Tokyo have reached 5000 nGy.

5000 nGy is 5uGy (5 micro Grays). Average X-ray is 1.4 mGy (1.4 milli Grays), which is 1400 uGy. i.e. after 280 hours (2 weeks) at 5000 nGy/h, you'll be getting equivalent of one X-ray of radiation.

The population of the prefecture is 3 million.

[Middle-aged Europe]

French nuclear agency disagrees with Japan's assessment that Fukushima is a level 4 incident on the INES scale and says that it is rather a 5 or 6. This would make it as bad or worse than Three Mile Island without reaching Chernobyl levels.

http://www.scientificamerican.com/article.cfm?id=update-1-french-nuclear-agency-rate

[minionofmidas]

French nuclear agency disagrees with Japan's assessment that Fukushima is a level 4 incident on the INES scale and says that it is rather a 5 or 6. This would make it as bad or worse than Three Mile Island without reaching Chernobyl levels.

Merci, Capitain Obvieux.

[True Federalist (진정한 연방 주의자)]

French nuclear agency disagrees with Japan's assessment that Fukushima is a level 4 incident on the INES scale and says that it is rather a 5 or 6. This would make it as bad or worse than Three Mile Island without reaching Chernobyl levels.

Merci, Capitain Obvieux.

It's hardy obvious that a 5 or 6 would be worse than a 4.  In fact there would be some logic in having a level 1 incident be the worst possible incident in which there would be anyone left on Earth to care what level an incident was.

[Middle-aged Europe]

French nuclear agency disagrees with Japan's assessment that Fukushima is a level 4 incident on the INES scale and says that it is rather a 5 or 6. This would make it as bad or worse than Three Mile Island without reaching Chernobyl levels.

Merci, Capitain Obvieux.

It's hardy obvious that a 5 or 6 would be worse than a 4.  In fact there would be some logic in having a level 1 incident be the worst possible incident in which there would be anyone left on Earth to care what level an incident was.

I don't really get what you mean.

IAEA defines level 1 as:

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How would this leave nobody behind "to care what level an incident was"?

[J. J.]

French nuclear agency disagrees with Japan's assessment that Fukushima is a level 4 incident on the INES scale and says that it is rather a 5 or 6. This would make it as bad or worse than Three Mile Island without reaching Chernobyl levels.

http://www.scientificamerican.com/article.cfm?id=update-1-french-nuclear-agency-rate

The US has been surpassed by the Japanese once again.