Isn't plutonium what they put on that Russian guy's Sushi in London to assassinate him?

Wow, I must say, I'm REALLY impressed with some of the knowledge on this forum. I have basic college level physics (engineering degree, but physics was long, long ago and my weakest subject actually, only three grades that were not A's, and only C was in physics, engineer who doesn't get physics, lol), but couldn't come close to what I see here.

Etika,
I've seen this more than once, about hot shutdown taking 24-48 hours. It's been 48 hours since the earthquake and we aren't out of the woods yet. Maybe you can answer for those of us who are more simple-minded........ is that timeline extended in these kinds of shutdowns, because without sufficient cooling the excess heat continues to catalyze fission within the reactor cores? What kind of timeline are we looking at now, until either reactors are shutdown or they go into full meltdown? Do we know?

The pictures coming in from the villages in Japan that got hit by the tsunamis are humbling. My heart and prayers go out to the Japanese people. It makes one appreciate just how fragile life can be and how easily one's best plans can be laid in tatters.

.

Reuters - The Japan Atomic Power Co. says the cooling process is working at its Tokai No. 2 Nuclear Power Plant

Workin: MOX is hated by a large number of people for two reasons:

1. It contains plutonium. That's bad stuff remember? You know, bombs and all? Yeah.

2. It is true that plutonium is also a long-lived cancer-causing agent in the environment and as a heavy metallic element it's chemically poisonous. But so are a lot of other things that get produced in a reactor. The one characteristic that's especially bad with plutonium, however, is that it is reactive in atmospheric water vapor and the oxide formed makes the metal pyrophoric - in other words, it can catch fire and burn.

Plutonium isn't particularly hazardous in the environment per-se, at least not more so than other metals - it's the risk of ingestion or inhalation (the latter especially) that's the problem, as it's a strong alpha emitter. And since its pyrophoric and can get into the atmosphere, inhalation risks are real.

What we ought to be doing is using it as MOX here in the US once for fuel (you can only run one cycle this way in a light-water reactor) and then again in fast breeders (where it will burn as fuel), but oops - we don't have any of the latter since we stopped all interest in them after Fermi I.

Quote:

Isn't plutonium what they put on that Russian guy's Sushi in London to assassinate him?

That was polonium, IIRC.

Ihtfp: No, that was polonium. Tiny amounts of it are in your smoke detector (that's the ionization source that is necessary to detect the smoke)

The Norwegian Radiation Protection Authority (NISA equivalent) just released an updated assesment: 16:16 UTC
(I must say it's a bit concerning they are doing updates on a Sunday, they are obviously on heightened alert)

Fukushima Dai-ichi


The situation at the reactor 3 deteriorated this morning.
What we do know is that there is damage to the housing of the fuel since the radioactive substances are released.
The casing is still intact
That is both(!) reactor #1 and #3
Reactor #1 and #3 both(!) has low water levels so the upper fuel rods are not covered with water
It is also a possible build up of hydrogen gas in reactor 3 which one fears may lead to an explosion.


Fukushima Dai-ini

Situation is unchanged. Reactor 1, 2 and 4 have reported pressure problems and emergency cooling has been implemented.

At Onagawa


It is registered increased radiation level at 23.30 local time, just outside the plant. The nuclear power plant has taken special measures.


Meteorological conditions

The wind direction seems to change in relation to the message yesterday.
In a hypothetical release at midnight tonight,
the forecast spread northeast and then turning south.



The model shows how air masses spread by any emissions at 0100 Norwegian time on March 14.
The asterisk indicates reactor.
End of line is 48 hours ahead of time.
The figure is based on an American model and met.no have run the simulation.

Advice to Norwegians in Japan

Norwegian citizens are encouraged to follow the Japanese authorities' recommendations.
So far this applies to evacuation from the given evacuation zone.
You are encouraged to respect these.
Radiation assessment is that it still will not be radiation-related reasons for a evacuation of Norwegians from Japan.


So from this we can conclude that in about 24 hours, wind direction will be straigt from Fukushima direction Tokyo

Quote:

I've seen this more than once, about hot shutdown taking 24-48 hours. It's been 48 hours since the earthquake and we aren't out of the woods yet. Maybe you can answer for those of us who are more simple-minded........ is that timeline extended in these kinds of shutdowns, because without sufficient cooling the excess heat continues to catalyze fission within the reactor cores? What kind of timeline are we looking at now, until either reactors are shutdown or they go into full meltdown? Do we know?

The 24-48 hours is the timeline if the heat removal is working. If it's not, all that heat that has been generated will remain in the system. While some heat is removed through normal conduction, even the lower levels of decay heat production now present is easily more than that. And the system is also pretty well isolated as you don't want every equipment in the plant reaching 300 degrees Celsius during normal operations...

So, basically that extra heat is just sitting there in the system. How long it'll take before they reach cold shutdown depends totally on the status of the cooling systems, more specifically how fast they are removing the heat (or if they are just keeping equalibrium at the moment). The information on the status of cooling systems is so lacking that it's impossible to give even an educated guess.

Reuters - Japan Atomic Power says 2 of 3 diesel generators for the Tokai No. 2 plant are down, but the remaining generator is sufficiently cooling the reactor

David Piper Fox News - If inside the evac zone, remove all clothing when coming in from outdoors and put in plastic bag. If still evacuating, wear wet clothes and wet flannel over face - per Japanese TV.

Quote:

Workin: MOX is hated by a large number of people for two reasons:

MOX is also hated by most nuclear engineers as it has nasty habit of causing positive reactivity spike right after a fast shutdown. If a MOX-fuelled reactor hits scram right after refuelling, it may enter an oscillating state where the reactor regains criticality for about 5 seconds every 30 seconds even with all control rods fully inserted. These spikes start at about 10% nominal maximum power and every one is smaller than the previous one, but you can imagine it's still not something you would want after a scram.

The effect passes about after about a month of use after refuelling as the total reactivity in reactor is decreased as fuel is used up, but it still something many operators and regulators do not like.

Etika & Genesis: Thanks..I thought I read that the MOX in Reactor 3 was newly installed fuel......I second what BigBuffer says above..Man, There's alot of knowledge here....

From BBC Twitter feed (times are GMT)

Quote:

1600: At the same time, Malcolm Crick, the secretary of the UN Scientific Committee on the Effects of Atomic Radiation, has told the Reuters news agency: "This is not a serious public health issue at the moment. It won't be anything like Chernobyl. There the reactor was operating at full power when it exploded and it had no containment."
1558: He described the worst-case scenario: "It is difficult to say, but that would be a core meltdown. If the rods fall and mix with water, the result would be an explosion of solid material like a volcano spreading radioactive material. Steam or a hydrogen explosion caused by the mix would spread radioactive waste more than 50km. Also, this would be multiplied. There are many reactors in the area so there would be many Chernobyls."
1553: He accused the government of deliberately withholding vital information that would allow outside experts help solve the problems. "For example, there has not been enough information about the hydrogen being vented. We don't know how much was vented and how radioactive it was." He also described the use of sea water to cool the cores of the reactors at Fukushima-Daiichi as highly unusual and dangerous.
1548: Mr Goto said the reactors at the Fukushima-Daiichi nuclear plant were suffering pressure build-ups way beyond that for which they were designed. There was a severe risk of an explosion, with radioactive material being strewn over a very wide area - beyond the 20km evacuation zone set up by the authorities - he added. Mr Goto calculated that because Reactor No 3 at Fukushima-Daiichi - where pressure is rising and there is a risk of an explosion - used a type of fuel known as Mox, a mixture of plutonium oxide and uranium oxide, the radioactive fallout from any meltdown might be twice as bad.
1541: A former nuclear power plant designer has said Japan is facing an extremely grave crisis and called on the government to release more information, which he said was being suppressed. Masashi Goto told a news conference in Tokyo that one of the reactors at the Fukushima-Daiichi plant was "highly unstable", and that if there was a meltdown the "consequences would be tremendous". He said such an event might be very likely indeed. So far, the government has said a meltdown would not lead to a sizeable leak of radioactive materials.

http://www.bbc.co.uk/news/world-middle-e....

Not Good!

The good thing is, that there is always something to learn. It is way better to submerge the reactor in seawater. Even if it seals its fate as comercial usable, and it will create severe corrosion problems in the upcomming years.
A simple high ground fire water pool would be now worth a fortune here.

The alternative is a core meltdown with a possile hydrogen explosion when the molten rods will hit water at the bottom. This would spread core material into the atmosphere and create a large no go zone.

I would take the alternative of a semi open loop cooling with seawater every time. Even if some of it enters into the ground or the ocean.

The other thing to learn is that we need a much harder look at the diesels, their air intake and electrical installation. The failure rate is way too high here.

Chris11 wrote..

The other thing to learn is that we need a much harder look at the diesels, their air intake and electrical installation. The failure rate is way too high here.

I don't know that there's much you can do to design around a 10 meter fast moving wall of water. A better strategy is to use reactor designs that don't require electricity for emergency cooling at all.

How about you dont build them in an earthquake zone along a coastline at sea level?? It appears to me the tsunami has played a significant role in the damage to the plant and why they are in the predicament they are presently in.

You need water for cooling, and lots of it, with conventional plants due to the Rankine-cycle turbines (if you want reasonable efficiency, that is.)

Therefore you're somewhat-limited in where you can put the plants.

Quote:

"If There Were a Reactor Meltdown or Major Leak at Fukushima, the Radioactive Cloud Would Likely be Blown Out ... Towards the US West Coast"
...
While US nuclear experts acknowledged the seriousness of Japan's reactor crisis, some stressed that taking steps in the United States such as distributing iodine tablets -- which prevent iodine 131 from being absorbed into the body -- would be "vastly premature."
...

http://www.zerohedge.com/article/if-ther....


yes— we mustn't get ahead of ourselves

My 2ct: Build the reactors into the granite itself. Why do it on land, then disassemble it just to bury it in granite finally? Go into an existing cavern, with stable walls and good geology, build the reactor there, with very lax standards and once its exhausted pull the plug and let it go china syndrome. Let it melt on purpose, it wont get far through dispersion, etc. Voila, instant final storage, or however you call it. Seal it with an explosion and go to another cave. For good effect do a mountaintop removal plus a "Hollywood" size carving of warning symbols on top. Control room stays above ground with a big red "Emergency Seal" button, and mostly remote operation. Designed to fail, and therefore inherently safer.

"Plutonium is very poisonous in particulate form in the environment."

Uh huh... really? Not saying it's good, but come on... there are other dangerous things out there too.

http://russp.org/BLC-3.html
http://www.nrc.gov/reading-rm/doc-collec....
More: http://www.google.se/#hl=sv&xhr=t....

What has happened here?

There's no particular reason to believe that ANY material level of radioactive iodine would reach US shores. Anywhere.

Blocking your thyroid (which is all that such a pill or solution does) is NOT without risk and SHOULD NOT be undertaken unless the risk of exposure is material and imminent.

THERE IS NO SUCH RISK IN THE US EVEN IN A FULL-ON MELTDOWN INCIDENT IN JAPAN.

If you wish to buy and have potassium iodide (I suggest the reagent - it is not a controlled chemical as it is NOT a useful precursor to anything nasty and is available through ordinary commercial channels) to guard against the possibility of nuclear accident (or attack) HERE in the US, that's fine. But buying it for imminent use as a consequence of the Japanese situation is not only idiotic if taken it has a material risk that is being undertaken without any reason whatsoever.

What's the reagent - Iodate? Typo - NOT a useful precursor...

Fukushima 3 was loaded with MOX last August.....However the MOX had been stored onsite since 1999 because the governor of the prefecture & activists opposed loading it....