8.9 Earthquake has struck Japan

[N Parker]

Taken from ki4u.com.....10 000 microsieverts = 1 rem (R)...so if we have 3200 uSeiverts, your looking at .32 R an hour absorption. Not bad at all when at "wartime", but bad for those being exposed to it everyday....


TOTAL EXPOSURE ONSET & DURATION OF INITIAL SYMPTOMS & DISPOSITION

30 to 70 R From 6-12 hours: none to slight incidence of transient headache and nausea;
vomiting in up to 5 percent of personnel in upper part of dose range. Mild
lymphocyte depression within 24 hours. Full recovery expected. (Fetus damage
possible from 50R and above.)

70 to 150 R From 2-20 hours: transient mild nausea and vomiting in 5 to 30 percent of
personnel. Potential for delayed traumatic and surgical wound healing,
minimal clinical effect. Moderate drop in lymphocycte, platelet, and
granulocyte counts. Increased susceptibility to opportunistic pathogens.
Full recovery expected.

150 to 300 R From 2 hours to three days: transient to moderate nausea and vomiting in
20 to 70 percent; mild to moderate fatigability and weakness in 25 to 60
percent of personnel. At 3 to 5 weeks: medical care required for 10 to 50%.
At high end of range, death may occur to maximum 10%. Anticipated medical
problems include infection, bleeding, and fever. Wounding or burns will
geometrically increase morbidity and mortality.

300 to 530 R From 2 hours to three days: transient to moderate nausea and vomiting in 50
to 90 percent; mild to moderate fatigability in 50 to 90 percent of personnel.
At 2 to 5 weeks: medical care required for 10 to 80%. At low end of range,
less than 10% deaths; at high end, death may occur for more than 50%.
Anticipated medical problems include frequent diarrheal stools, anorexia,
increased fluid loss, ulceration. Increased infection susceptibility during
immunocompromised time-frame. Moderate to severe loss of lymphocytes.
Hair loss after 14 days.

530 to 830 R From 2 hours to two days: moderate to severe nausea and vomiting in 80 to
100 percent of personnel; From 2 hours to six weeks: moderate to severe
fatigability and weakness in 90 to 100 percent of personnel. At 10 days to
5 weeks: medical care required for 50 to 100%. At low end of range, death
may occur for more than 50% at six weeks. At high end, death may occur
for 99% of personnel. Anticipated medical problems include developing
pathogenic and opportunistic infections, bleeding, fever, loss of appetite,
GI ulcerations, bloody diarrhea, severe fluid and electrolyte shifts, capillary
leak, hypotension. Combined with any significant physical trauma, survival
rates will approach zero.

830 R Plus From 30 minutes to 2 days: severe nausea, vomiting, fatigability, weakness,
dizziness, and disorientation; moderate to severe fluid imbalance and headache.
Bone marrow total depletion within days. CNS symptoms are predominant at
higher radiation levels. Few, if any, survivors even with aggressive and
immediate medical attention.

 

[Darren Addy]

TEPCO:Fuel rods exposed at Fukushima reactor
Tokyo Electric Power Company is battling to cool a reactor to prevent another explosion at its nuclear power plant in quake-hit Fukushima Prefecture.

The utility firm said on Monday afternoon that fuel rods are exposed at the Number Two reactor of its Fukushima Number One plant after the level of coolant water dropped. At around 6:20pm, the power company began pumping in seawater.

Tokyo Electric says it had to halt the process due to fuel loss for the pumping system, possibly leaving the fuel rods in the reactor exposed. The firm says a core meltdown might have occurred.

The Nuclear and Industrial Safety Agency says that pumping seawater into the reactor is working now.

Earlier in the day, the firm told the government that the reactor had lost all cooling capability due to a failure of the emergency power system.

Since then, the company has tried to circulate the coolant by steam instead of electricity. But attempts to lower the temperature inside the reactor chamber have not worked well.

The company is also considering opening a hole in the reactor housing building to release hydrogen generated by the exposed fuel rods.

Accumulated hydrogen has caused blasts at two other reactors at the plant.
Monday, March 14, 2011 20:36 +0900 (JST)

- source

"I need some volunteers on the roof of No. 2. Pay no attention to the condition of the roofs on either side of you."

 

[Scott Weberpal]

Japan Nuclear Disaster Risk Seen Receding Fast:

http://www.reuters.com/article/2011/03/14/us-japan-nuclear-radiation-risk-idUSTRE72D6UC20110314

(Reuters) - The risk of a major radiation leak in Japan is subsiding as stricken nuclear reactors cool, but there will be major clean-up costs and three reactors will probably be written off, experts said on Monday.

 

[Darren Addy]

(Reuters) - The risk of a major radiation leak in Japan is subsiding as stricken nuclear reactors cool, but there will be major clean-up costs and three reactors will probably be written off, experts said on Monday.

News organization boss: "We're desparate for content. Get me Capt. Obvious on the phone, STAT!"


After watching NHK World TV explanation, I agree with the engineer that designed the plant. If coolant is not covering the rods, then it is leaking out from somewhere (either as liquid water or steam). That indicates a breach of the most internal reactor housing. If that is correct, then it isn't the 2nd line of defense housing (steel enclosing the reactor itself) that is the only thing between the core and the outside world? If they don't vent that they risk a rupture/explostion as pressure in it rises.

 

[Benjamin Smith]

It will be interesting to see how this plays out. I don't believe the major media saying that things are looking better. They just admitted today that the cores were exposed and meltdowns have already occurred or are in the process of occurring. Seems to me they have been lying all along and people will die as a result. Kind of sickening. I just hope they can keep as much radiation contained as possible.

 

[Darren Addy]

I just caught the last part of an audio news report that said that "they are unable to vent pressure from one of the reactors and it is an emergency situation" ???
Anybody know what unit that might be referring to? Looking for confirmation link.
If true, this is potentially huge.

"Chernobyl on Steroids" possible

fears mounted about the threat posed by the pools of water where years of spent fuel rods are stored.

At the 40-year-old Fukushima Daiichi unit 1, where an explosion Saturday destroyed a building housing the reactor, the spent fuel pool, in accordance with General Electric’s design, is placed above the reactor. Tokyo Electric said it was trying to figure out how to maintain water levels in the pools, indicating that the normal safety systems there had failed, too. Failure to keep adequate water levels in a pool would lead to a catastrophic fire, said nuclear experts, some of whom think that unit 1’s pool may now be outside.

“That would be like Chernobyl on steroids,” said Arnie Gundersen, a nuclear engineer at Fairewinds Associates and a member of the public oversight panel for the Vermont Yankee nuclear plant, which is identical to the Fukushima Daiichi unit 1.

People familiar with the plant said there are seven spent fuel pools at Fukushima Daiichi, many of them densely packed.

Gundersen said the unit 1 pool could have as much as 20 years of spent fuel rods, which are still radioactive.

also

Japanese officials were also trying to figure out whether Friday’s earthquake, or the subsequent high pressures and temperatures in the reactors, had caused other cracks or leaks in reactors in the region. So far officials have not said that they have found any, though they have noted still unexplained losses of water in some reactor vessels.

- source

Also from the BBC:

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.

 

[Greg Campbell]

"Meltdown, MELTDOWN!" is all we've been hearing from the Tee Vee idiots.

There's a big difference between 'overheated, pissed off fuel rods' and 'meltdown.'

There's a big difference between a few rods melting and the entire core laying in a boiling pool on the bottom of the vessel.

AFAIK, the containment is designed to 'catch' a blazing hot core that has suffered a runaway nuclear reaction. With the reactor shut down for some time, and decay heat falling, even a core melt should be much easier to deal with.

We hope.

 

[Ryan McGinnis]

It hasn't been leaking out due to a rupture in containment, it's been leaking out because they've been intentionally opening valves to decrease the pressure inside the reactor. When the rods are intact, this isn't a big deal as the radioactive isotopes released into the containment buildings (that keep blowing up) and the atmosphere have half lifes of seconds. As the fuel starts to melt, though, each pressure release starts dumping Bad Things like radioactive cesium and iodine into the containment buildings (that keep blowing up) and atmosphere.

I guess it depends on how people define 'breach'. To me, any time you are venting fissile materials into the atmosphere that are supposed to stay in the reactor, that's a breach, even if minor.

The containment buildings (that keep blowing up) are supposed to have a powered filtration system that traps radioactive particles in charcoal filters before discharging the air into the atmosphere. With the power out, this hasn't been happening. A side effect of this is that because the gases are not beig mechanically purged from the building, byproducts of a fuel rod damage like hydrogen build up inside the building. Thus the idea to punch a hole in the building before it sends itself into orbit like the previous two.

 

[Greg Campbell]

Yea, I'm surprised they couldn't just "open a window" and vent the outer building.

 

[Ryan McGinnis]

I just caught the last part of an audio news report that said that "they are unable to vent pressure from one of the reactors and it is an emergency situation" ???
Anybody know what unit that might be referring to? Looking for confirmation link.
If true, this is potentially huge.

Hours ago on the BBC they mentioned that there was problems relieving pressure in the #2 reactor after the mishap that caused the rods to remain uncovered for a couple hours. This doesn't sound very likely, though, as these reactors literally have around a dozen different release valves they can blow to release steam pressure. Of course, I think they have to blow them now manually as there is no power, though I could be wrong (part of the problem is that by now it's rather hazardous for workers to get close enough to the equipment they need to operate, due to radiation levels). The report might be accurate as they said the reason they couldn't get more water into the reactor was due to pressure. The fire trucks operate on relatively low pressue compared to the high-pressure fail-safe water injection systems that are supposed to be running right now (but are not, due to a power outage at the power plant).

*edit* Found an updated quote from the BBC:

Nuclear and Industrial Safety Agency official Ryohei Shiomi said reactors 1 and 3 had "somewhat stabilised" but "unit 2 now requires all our effort".

The agency said workers were also battling rising pressure within the reactor. They have opened vents in the containment vessel, which could release small amounts of radiation.

Also:

The US said it had moved one of its aircraft carriers from the area after detecting low-level radiation 160km offshore.

Anyhow, if that report actually were accurate and they don't figure out how to dump the steam pressure, I suppose the first confirmation we'll have is the reactor itself blowing itself to the moon and shooting hot uranium on mile-long trajectories in every direction. That seems unlikely, though, but that'd be quite a sight if it happened.

 

[Ryan McGinnis]

Yea, I'm surprised they couldn't just "open a window" and vent the outer building.

The outer building is actually a hardened containment building itself. It's designed to be a failsafe containment system if the reactor fails. Of course, it's gone and blown itself up in buildings #1 and #3. This will probably be seen as a design flaw and re-engineered in future plants.

 

[Dan Robinson]

I always wondered why reactors aren't built deep underground or into the side of mountains. It doesn't seem like any amount of man-made containment is enough to protect against the worst-case scenario.

 

[Darren Addy]

It hasn't been leaking out due to a rupture in containment, it's been leaking out because they've been intentionally opening valves to decrease the pressure inside the reactor. When the rods are intact, this isn't a big deal as the radioactive isotopes released into the containment buildings (that keep blowing up) and the atmosphere have half lifes of seconds. As the fuel starts to melt, though, each pressure release starts dumping Bad Things like radioactive cesium and iodine into the containment buildings (that keep blowing up) and atmosphere.

I guess it depends on how people define 'breach'. To me, any time you are venting fissile materials into the atmosphere that are supposed to stay in the reactor, that's a breach, even if minor.

The containment buildings (that keep blowing up) are supposed to have a powered filtration system that traps radioactive particles in charcoal filters before discharging the air into the atmosphere. With the power out, this hasn't been happening. A side effect of this is that because the gases are not beig mechanically purged from the building, byproducts of a fuel rod damage like hydrogen build up inside the building. Thus the idea to punch a hole in the building before it sends itself into orbit like the previous two.

The part that I am missing the explanation for is how the water level goes down in the reactor itself. As I understand it, the venting is being done from the containment vessel (into the containment building) - not the reactor with the control rods & fuel itself. Illustrations I have seen show them using sea water to flood the containment vessel (not the reactor itself). Is the venting being done from the reactor into the containment vessel and from the reactor itself? It seems to me that all information given so far is that the reactor is still sealed to the outside world. If they were venting from the reactor itself that point would seem to be a moot one.

 

[Greg Campbell]

Yea, I know it actually a rather sturdy building. One drawing I saw suggested 2ft thick concrete walls. (Which makes the explosions all the more impressive - that wasn't drywall flying 100s of feet through the air!) Still, I'd think there would be some sort of vent that they could open. Better to release a few nasties than suffer a large explosion that could damage the rest of the reactor and its control systems.

 

[Darren Addy]

Here is an example post from BBC Live that explains my confusion:

2129: Tepco said water levels inside the containment vessel were not immediately rising to the desired level, possibly because of a leak. Nevertheless, an official told a news conference: "We do not feel that a critical event is imminent."
2126: Engineers were having difficulty injecting seawater into the reactor because its vents - necessary to release pressure in the containment vessel by allowing radioactive steam to escape - had stopped working properly, the New York Times reports. However, by Tuesday morning they had succeeded in opening a malfunctioning valve, reducing pressure in the container vessel. They then resumed flooding the reactor with water.

The top part is referring to the containment vessel (not the reactor). The bottom part is saying "into the reactor" and referring to "its vents" malfunctioning. Then they talk about opening "a malfunctioning valve, reducing pressure in the containment vessel". They just switched the subject. You don't reduce pressure in the containment vessel by opening a valve in the reactor (which is inside the containment vessel). Either somebody is using the wrong terms or else the inner reactor is breached so all efforts in flooding and venting are focused on the containment vessel.