OT: Massive 8.9 quake in northern Japan

[rtrapasso]

ORIGINAL: Cap Mandrake

This is true. I expereienced temporary amnesia about who is in charge in Washington. [:)]

If the pool really is 84C at atmospheric pressure it can't really be boiling, of course. Maybe the thermometer is stuck. [:)]

It does make one wonder what information the NRC had to make such a pronouncement. TDEC said at one point the fire in number 4 was a pump oil fire...maybe it was...but where did the big radiation spike come from at the same time? I remain very suspicious that there is deliberate underreporting or simple misdiagnoisis of problems by TDEC. Can you imagine the Hell those guys are going through at the plant?

From what i read, the fire at #4 was caused when the "cooling pool" went dry, allowing (apparently overpacked) spent fuel rods to overheat and catch on fire, thus the rather large release of radiation. Some Russian who investigated Chernobyl was pretty pointed in his criticism of the overpacking, although whether he is correct in his assertions is unknown to me.

i suppose if there was a pump nearby, its oil caught on fire as well... [8|]

BTW - no. 3 "cooling pool" is apparently facing a similar crisis now. Supposedly the water keeps disappearing from the cooling pools and they are not sure how this is happening. i suspect that since the pools are located well above ground that there may be cracks caused by the quake, and thus a major leak.

See attached drawing - the "SF" area on the THIRD level up is where the spent fuel (pool) is apparently located.



EDIT:
This is a sketch of the Mark I containment type used in reactors 1-5; no. 6 has a more advanced Mark II "over/under" containment system. DW = dry well; WW = wet well

No. 3 reactor is the "MOX" mixed oxide reactor that has plutonium (which is particularly worrisome to the Japanese), the other reactors apparently running straight enriched uranium.

[Cap Mandrake]

According to ABC News, a US spokesperson told ABC that the spent fuel rods were "glowing red" and could be seen by satellite from space. [&:]

This is at least possible as the roof is apparently blown off number 4. Idon't know how hot they would have to be to be seen with a visible light image but there is certainly some kind of IR sensor too as they are used to detect missile launches.


If the US government is cynnically releasing stuff like this to placate domestic concerns then all I can say is ..."Wow". When I hear stuff like it has the opposite effect.

[rtrapasso]

A few radiation facts about Fukushima:

Radiation levels of 250 millisievert an hour had been detected 30 meters above the plant.

On Tuesday Japan's health ministry raised the cumulative maximum level for nuclear workers from 100 millisievert to 250 millisievert.

Typical dose for a nuclear power plant worker is about 20 millisieverts in a year.

If the cooling pools/spent rods are exposed (i.e. - due to low water levels), radiation beside the exposed rods would deliver a fatal dose in 16 seconds.

The cooling pools are supposed to be kept at 25 deg. C or less; current water temps in no. 4 pool are said to be 84 deg. C (although the pool is also said to be pretty much empty), and in no. 5 and no.6 cooling pools to around 60 deg. C. (and climbing). Apparently pools 5 and 6 are also leaking.

Currently, "the water levels in all three reactors (apparently nos. 2, 3, 4 actual reactors, not the cooling pools) are dangerously low, exposing between 1.4m and 2.3m of the fuel rods" (which should be completely covered to prevent a meltdown).

[rtrapasso]

This is at least possible as the roof is apparently blown off number 4.

Probably burned off... this cooling pool had the fire. Nos. 1-3 had hydrogen explosions, more or less blowing the roofs off. Here's a photo of unit 1 before and after the hydrogen explosion:



EDIT: Reading some more on this, supposedly the cooling pools are exposed on top so that they should be able to be seen from above even without damage. Apparently, this has allowed the strategy of "water bombing" and fire hose "cannons" to attempt to fill the pools, however, debris from the explosions, tsunamis, fires are interfering with attempts (not to mention the high radiation levels keeping workers from getting too close).

[Mark VII]

It would seem that they are wasting their time with the helicopter water drops. The Chinooks seem way to high when making the drop and the water appears to be only mist when it reaches the ground. I thought they need lots of water to try to fill the pools to cover the rods. Though, if I'm driving one of those Chinooks, don't think I want get to low over those exposed rods.

Either way, some very brave and determined people over there trying to prevent further disaster.

ORIGINAL: rtrapasso

This is at least possible as the roof is apparently blown off number 4.

Probably burned off... this cooling pool had the fire. Nos. 1-3 had hydrogen explosions, more or less blowing the roofs off. Here's a photo of unit 1 before and after the hydrogen explosion:



EDIT: Reading some more on this, supposedly the cooling pools are exposed on top so that they should be able to be seen from above even without damage. Apparently, this has allowed the strategy of "water bombing" and fire hose "cannons" to attempt to fill the pools, however, debris from the explosions, tsunamis, fires are interfering with attempts (not to mention the high radiation levels keeping workers from getting too close).

[Mynok]

They gotten power to the site now.

http://www.bbc.co.uk/go/rss/int/news/-/ ... c-12779512


FYI, this is the best information I've found in presentation and explanatory power.

http://web.mit.edu/newsoffice/

See also: http://mitnse.com/

[khyberbill]

I have been trying to refrain from posting until I have all the facts about what went wrong in Fukushima-but I suspect that wont be available for awhile. I have actually been to the Fukushima site on business in 1998 but my reactor expertise was with PWRs and not BWRs. I did spend a year removing highly radioactive components from the spent fuel pools of two American BWRa and can say that the building structure above spent fuel pools in PWRs and BWRs are not designed to contain a hydrogen explosion-or most any other type. As some recall, there was a hydrogen explosion at Three Mile Island although it was in the containment.

I wonder how the industry is going to address the problem going forward? In the high radiation flux inside the reactor, water is broken down into H and O. O being very reactive is not desirable (it causes rust and rust gets to become very radioactive Mn54, Co60 etc) and so H is added to reactor water to recombine the free O into H2O. This explosive potential will exist as long as water is used as a coolant. CO2 and sodium have been briefly used but discarded. I imagine these hydrogen explosions will be a weapon for the anti-nukes in any future licensing effort-at least here in the US. I know I am interested in how current or future designs mitigate the problem.

[witpqs]

Fukushima one week on: Situation 'stable', says IAEA

First paragraph:

The situation at the Fukushima Daiichi nuclear powerplant in Japan, badly damaged during the extremely severe earthquake and tsunami there a week ago, continues to stabilise. It is becoming more probable by the day that public health consequences will be zero and radiation health effects among workers at the site will be so minor as to be hard to measure. Nuclear experts are beginning to condemn the international hysteria which has followed the incident in increasingly blunt terms.

[Cap Mandrake]

ORIGINAL: witpqs

Fukushima one week on: Situation 'stable', says IAEA

First paragraph:

The situation at the Fukushima Daiichi nuclear powerplant in Japan, badly damaged during the extremely severe earthquake and tsunami there a week ago, continues to stabilise. It is becoming more probable by the day that public health consequences will be zero and radiation health effects among workers at the site will be so minor as to be hard to measure. Nuclear experts are beginning to condemn the international hysteria which has followed the incident in increasingly blunt terms.

That seems a little too glib. I agree there has been hysteria with reporters describing a couple of fly bys in choppers as "suicide missions". If anybody knows what a real suicide mission is it should be the Japanese. [;)]

On the other hand, to describe the situation as "stable" when they are trying to cool partially uncovered spent fuel rods with fire hoses from 6 stories below seems like serious spin to me. [:)] With the power soon to arrive, it does look like they will avert a major and long-lived catastrophe. Still, somebody is going to have to find a BIG hole to bury all that crap.

Anybody else wonder what is happening to the now likely radioactive water running down the side of the buidling?

[witpqs]

I don't think the fuel rods are only partially covered at this point. I forget the exact numbers, but the rods are something like 14ft and the pools 45ft deep, so the rods are covered long before the pools are full. It's been a couple of days since they visually verified (see that MIT site linked earlier) that the rods in pool #4 were covered and turned attention to putting water on pool #3 (which was never asserted to be empty or too low).

If the facts we are presently told are accurate, I think stable is a fair assessment. Nothing is deteriorating and even maintaining current actions things are getting better. Of course there is further progress with additional electricity supplies and so on. Stable isn't meant to imply "let's walk away and take a smoke break".

As far as the media goes, I'm not sure which reports you saw, but I saw reports & headlines about the whole crew of workers at the plant as being on a suicide mission, was it even possible to avoid a full-scale meltdown and catastrophic radiation release, it is impossible to avoid..., x-number of people outside the plant diagnosed with radiation toxicity, seafood in the Pacific to be contaminated, and on and on.

I doubt the water runoff has any meaningful level of radioactive contamination, due to the nature of its exposure and its quantity (i.e. dilution). Whatever it has is most likely the really short half-life stuff and it can just sit there for a few weeks.

Of course, what is not stable are scenes like the riots in some parts of China over buying salt to avoid being poisoned radioactive Iodine from Japan... [X(]

[Cap Mandrake]

ORIGINAL: witpqs


As far as the media goes, I'm not sure which reports you saw, but I saw reports & headlines about the whole crew of workers at the plant as being on a suicide mission, was it even possible to avoid a full-scale meltdown and catastrophic radiation release, it is impossible to avoid..., x-number of people outside the plant diagnosed with radiation toxicity, seafood in the Pacific to be contaminated, and on and on.

Yep..saw those examples. Obvious hyperbole. I agree. As a gag, at our annual stockholder meeting this Tuesday I gave everyone iodized salt before my candidate's speech....which was all of two sentences. I can't lose....literally (nobody ran against me).

[JWE]

ORIGINAL: Cap Mandrake
Anybody else wonder what is happening to the now likely radioactive water running down the side of the buidling?

Water isn't intrinsically radioactive. Radioactivity isn't something that exists in a vacuum and is transfered from place to place, it's an intrinsic property of the material you are looking at. It's a function of how stable or unstable an atomic nucleus is under various isotope conditions (again dependant on the stability or instability of the base isotope in the periodic table).

Water is Hydrogen and Oxygen. Hydrogen doesn't get radioactive unless it becomes Tritium, with two neutrons, and that takes monster energy in the fusion range to accomplish. Oxygen is a bit more problematic because it is a heavier element and can fiss as well as fuse, but the only observed radioisotopes of Oxygen require a great deal of energy to create, and have half lives of between 80 ms and 120 seconds. The energy required to create O(15) for example, means that about 1 in 700 trillion Oxygen atoms have a 50% chance to go to O(15) if the energy level is high enough, and they will decay in a heartbeat.

The only witch is sea water, that has certain trace elements in it's composition, but even these trace elements have radio isotopes that are highly unstable and have very short half-lives, and require vast amounts of energy to convert them into isotopes that have any significant effect, and those isotopes still have a 1 in 100 trillion chance of occurance [ed] and given their trace occurance in sea water, we're talking about 9 billionths of 100 trillionths [], so rational reports that say drinking the cooling water after five minutes is no worse than surfing Old Mans for three hours, in July, without a wetsuit, appear to be based in scientific reality.

[khyberbill]

I doubt the water runoff has any meaningful level of radioactive contamination

Well, the runoff will have lots Co60 with a half life of 5+ years and two nasty 1+ MeV gamma rays per decay. There will also be lots of Cs134/137 which is highly soluble so should wash to the sea where it will be readily absorbed by sea and plant life. However, the Co is going to be a problem. It tends to be a fine particulate and will readily travel in the wind.

I agree with the Cap that the IAEA report was too glib. From my point of view the place will be stable only when all the reactors are being cooled as per the normal shutdown procedures (which should happen once they have electricity and any required repairs) and the spent fuel pools are covered from the elements with some sort of controlled cooling mechanism in place (spray from fire hose from the sea or trucks doesnt count)and no or very low leakage of radioactivity (air or water).

[witpqs]

Where would the Co60 come from? The reactor containment vessels have not been breached.

[ChezDaJez]

It's nice to get good information without all the doom and gloom hyperbole that the press is spouting. That's what I love about this forum. People here have a wide range of expertise on nearly every subject that matters... and some that don't!

Anyways, it sounds as though the situation is stabilizing, certainly not getting any worse at the moment and that in itself is a good sign. Hopefully, they will continue making progress.

Chez

[Cap Mandrake]

ORIGINAL: JWE

ORIGINAL: Cap Mandrake
Anybody else wonder what is happening to the now likely radioactive water running down the side of the buidling?

Water isn't intrinsically radioactive.

It is...a little bit. Both Tritium and unstable Oxygen isotopes occur naturally, but I was really talking about about the water from the fire hose carrying away radioactive particles that hade been deposited on the building or structures in the cooling pond support elements.

As for Tritium's production, it's not the result of fusion. It's the other way around. Tritium is one of the starting materials in the He4 fusion reaction.

.....so rational reports that say drinking the cooling water after five minutes is no worse than surfing Old Mans for three hours, in July, without a wetsuit, appear to be based in scientific reality.

Speaking of San Onofre, I heard yesterday the seawall there for tsunamis is 30 ft whereas the one at Fukushima is only 12ft. The greatest risk at Old Man's is getting the crap beat out of you for not showing proper deference to a local.

[Cap Mandrake]

ORIGINAL: witpqs

Where would the Co60 come from? The reactor containment vessels have not been breached.

I think the prevailing belief at the US NRA is there was a likely breech of at least one primary containment. I think it's 3 but can't remember now. There must also be some Co60 in the spent rods. I think it's a daughter product of Uranium fission. perhpas Khyber will tell us. [:)]

[Cap Mandrake]

ORIGINAL: witpqs

Where would the Co60 come from? The reactor containment vessels have not been breached.

I looked it up. Co60 comes from the bombardment of the Co59 that is present in steel.

[witpqs]

Thanks. How would it (any meaningful quantity of it) end up in the water?

[khyberbill]

Where would the Co60 come from? The reactor containment vessels have not been breached.

Lots of Co60 on the fuel rods. And other sources in the spent fuel pool. I used to ship stellite bearings from BWR spent fuel pools that were 30,000 REM/300 Sieverts (all from the Co60) at 1 inch from the surface to a supplier who would use them for radiation treatment devices. Not only is spent fuel in the pool but CDRMs (nasty things), old control rods and other reactor core, non-fuel hardware. We would ship the rods etc from the BWR spent fuel pool in a cask that was over six inches thick of depleted uranium and would still get readings on the surface of the cask of about .001 sieverts.