News Japan Earthquake, Tsunami, & Nuclear Disaster

[Urwumpe]

CNN reports sea water used to cool the reactor.

Yeah, second attempt now, the first one was stopped by a Tsunami warning.

Bad enough though, they plan to pump this into the pressure vessel and into the core of the reactor, which makes me feel pretty uneasy. Not that the loss of the reactor is really a problem, but corrosion is only one of the problems there. Another could be unknown nuclear reactions.

 

[Belisarius]

IR images of the reactor, because I am interested in the temperatures.

I'm guessing that only NASA operates IR sats apart from military agencies. Is that right? Would NASA share IR data if they had it?

 

[Urwumpe]

I'm guessing that only NASA operates IR sats apart from military agencies. Is that right? Would NASA share IR data if they had it?

You can get most such data (eg landsat) for free, but sadly only with some delay. I currently hope for some Proba data.

http://earth.esa.int/EOLi/EOLi.html

 

[Belisarius]

Looking at the Guardian article referenced by Coolhand above I see the following

However, Naoto Sekimura, a professor at Tokyo University, insisted there was little chance that Japan came close to experiencing a Chernobyl-style meltdown. "No Chernobyl is possible at a light water reactor," he said. "Loss of coolant means a temperature rise, but it also will stop the reaction. Even in the worst-case scenario, that would mean some radioactive leakage and equipment damage, but not an explosion.​

That doesn't square at all with the discussion above, particularly Urwumpe's analysis that the plant could progress from partial to full meltdown.

But it does square with the thesis that the Japanese govt is trying to conceal the dramatic nature of the problem

Comments?

 

[N_Molson]

Even if nothing worse happens, it is certainly a serious mess inside the reactor core and it will be nearly impossible to "clean". The only thing to do will be to seal it I guess...

 

[Urwumpe]

There should be already a terrible mess in the reactor, which sure did not get better by pumping salt water into it.

The only photograph from close of the exploded reactor also suggests some heavy damage above the containment...

Can't tell if the roof really collapsed first, the few parts I can identify as being roof parts hang outside.

 

[David413]

Just received the most recent update from Japan (via industry sources) which, unfortunately I cannot post verbatim. Most of what has been previously posted here is correct, although it seems to be missing the fact that boric acid has been added to the core along with the seawater. This will "poison" any possible nuclear reaction (the isotope boron-10 has one of the single greatest cross-sections for absorption of neutrons available and comprises about 20% of natural boron), so re-criticality is pretty much ruled out. As for the corrosive nature of seawater, unit one will most likely have to be de-fueled and retired. 35 years of nuclear engineering experience has it's advantages...

 

[Notebook]

35 years of nuclear engineering experience has it's advantages...

Is that ironic?

N.

 

[N_Molson]

As for the corrosive nature of seawater, unit one will most likely have to be de-fueled

I don't want to throw graphite on a melted core but that might prove difficult without causing massive radioactive leaks...

 

[Urwumpe]

Well, defueling is sure no problem since the unit was planned to be deactivated this month. But the lack of bad news so far is at least some kind of good news, seems like the emergency actions are getting the temperatures down.

 

[RGClark]

Just received the most recent update from Japan (via industry sources) which, unfortunately I cannot post verbatim. Most of what has been previously posted here is correct, although it seems to be missing the fact that boric acid has been added to the core along with the seawater. This will "poison" any possible nuclear reaction (the isotope boron-10 has one of the single greatest cross-sections for absorption of neutrons available and comprises about 20% of natural boron), so re-criticality is pretty much ruled out. As for the corrosive nature of seawater, unit one will most likely have to be de-fueled and retired. 35 years of nuclear engineering experience has it's advantages...

Battle to stabilise earthquake reactors
12 March 2011.
UPDATE 6: 10.15 am GMT
"Three of Fukushima Daiichi's six reactors were in operation when
yesterday's quake hit, at which point they shut down automatically and
commenced removal of residual heat with the help of emergency diesel
generators. These suddenly stopped about an hour later, and this has
been put down to tsunami flooding by the International Atomic Energy
Agency (IAEA).
"The loss of the diesels led the plant owners Tokyo Electric Power
Company (Tepco) to immediately notify the government of a technical
emergency situation, which allows officials to take additional
precautionary measures.
Even now, the primary focus of work at the site remains to connect
enough portable power modules to fully replace the diesels and enable
the full operation of cooling systems."
http://www.world-nuclear-news.org/RS_Battle_to_stabilise_earthquake_reactors_1203111.html

If the main problem is just getting enough portable power there then
there are portable gas turbine generators capable of putting out 10's
of megawatts. You could also use the power from a nuclear aircraft
carrier at a power range of 200 megawatts, though there might be concern about bringing it off shore in a zone subject to tsunamis.


Bob Clark

 

[Urwumpe]

If the main problem is just getting enough portable power there then
there are portable gas turbine generators capable of putting out 10's
of megawatts. You could also use the power from a nuclear aircraft
carrier at a power range of 200 megawatts, though there might be concern about bringing it off shore in a zone subject to tsunamis.

There are also reports about mobile generators to be on site, but these lacked the proper cable to connect to the US built pumps.

That only battery powered pumps had been working was a really big no-go, and will leave quite a few questions despite the series of earthquakes.

And yes, aside of the waters being a bit shallow for getting a nuclear aircraft carrier even in swimming distance of the power station, the tsunami risk is sure also a good reason to stay far away from the coast.

 

[Belisarius]

OK there's full daylight now - I checked NASA but their images are a day old. Any other sat imagery available? How about the IR?

 

[Linguofreak]

Looking at the Guardian article referenced by Coolhand above I see the following

However, Naoto Sekimura, a professor at Tokyo University, insisted there was little chance that Japan came close to experiencing a Chernobyl-style meltdown. "No Chernobyl is possible at a light water reactor," he said. "Loss of coolant means a temperature rise, but it also will stop the reaction. Even in the worst-case scenario, that would mean some radioactive leakage and equipment damage, but not an explosion.​

That doesn't square at all with the discussion above, particularly Urwumpe's analysis that the plant could progress from partial to full meltdown.

Meltdown just means that the fuel assembly has melted and flowed down into the bottom of the reactor core. That only leads to a Chernobyl-type scenario if there's actually a breach in the reactor core, either because of melt-through or, as in the case of Chernobyl, because of an explosion within the core itself. Three-mile island involved a melt down with no breach of the reactor core. In fact, I'm not sure that the meltdown at Chernobyl had run its course before the core breached.

 

[MeDiCS]

I can't find any imagery from ESA or JAXA, only three images from NASA.

 

[Belisarius]

Now number 3 reactor is at risk:

2326: The Japanese cabinet secretary, Yukio Edano, has been speaking on state TV. He said the third reactor at the Fukushima No. I plant was in danger but attempts were under way for a controlled release of air.

From BBC
http://www.bbc.co.uk/news/world-middle-east-12307698

I don't know why the BBC labels this thread Middle East

 

[N_Molson]

BBC News :

2318: US nuclear experts warn that pumping sea water to cool a quake-hit Japanese nuclear reactor is an "act of desperation" that may foreshadow a Chernobyl-like disaster, AFP reports. "The situation has become desperate enough that they apparently don't have the capability to deliver fresh water or plain water to cool the reactor and stabilise it, and now, in an act of desperation, are having to resort to diverting and using sea water," said Robert Alvarez, who works on nuclear disarmament at the Institute for Policy Studies.

 

[RisingFury]

:facepalm:

 

[Thunder Chicken]

I knew you Orbinauts would be talking about this :thumbup:

I've been trying to get some sensible news on the Japanese reactors. At one of my previous employers I did accident analysis on these reactors. All of the "news" that I can find is pre-apocalyptic hysteria, no real news at all. Is journalism really that dead? :facepalm:

Anyway - as far as I see, I understand that there was an explosion and failure of the outer containment of Fukushima Daiichi unit 1, inner containment apparently OK but problems with the emergency core cooling system. Also, Fukushima Daiichi unit 3 is having cooling problems.

Initial reports discussed 5 different reactors having problems. Any word about the others or did they shutdown OK?

Japan has been gearing up for the Big One for years - their disaster response in spite of this chaos has been amazing. Not to say that this isn't a horrible disaster, but without their civil preparedness this could have been much, much worse (as hard as that is to fathom).

 

[Urwumpe]

Can't find any research about the topic yet, but one source claimed that nuclear submarines account for the expansion of the reactor during start up by adding seawater to the system, but there is no information if desalinated or not.