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Video of reactor 1 at Fukushima plant
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Re: Video of reactor 1 at Fukushima plant
#62Re: Video of reactor 1 at Fukushima plant
#63Earlier quoted context omitted.
Japanese authorities are extending the evacuation zone around the two Fukushima nuclear plants from 10km to 20km, according to local media.
Well, judging from past nuclear accidents (Chernobyl, 3 mile island), I would: 1.) Not trust the government, the plant operator, the plant designer, hell anyone remotely involved. They always downplay whatever is really going on to prevent panic (or divert blame) 2.) Get as far away as possible, preferably in the opposite direction of prevailing winds.
In Japanese radio a professor was saying to get 100-200km away.
Re: Video of reactor 1 at Fukushima plant
#64Real quick, what does that mean for the rest of the world? Do we have to fear something?
Still hard to say. Fortunately, the wind is forecast to go out towards the Pacific for the next few days. But if the situation escalates as badly as Chernobyl, enough stuff may get out for everyone to get some.
Re: Video of reactor 1 at Fukushima plant
#65Real quick, what does that mean for the rest of the world? Do we have to fear something?
Yes, you will likely be death in the next 100 years.
Seriously though the structure that contained the reactor isn't the only thing that protects the reactor (it was at Chernobyl, which is why it went badly) it is also protected by a thick concrete container (which is pretty much what was eventually built around the Soviet reactor) which means that in the event of a meltdown the structure will contain the radioactive stuff.
So in summary: unless you are really close (which you shouldn't be) or have a burning desire to be inside that reactor building you will die of something else entirely (most likely something boring).
Re: Video of reactor 1 at Fukushima plant
#66Earlier quoted context omitted.
Japanese authorities are extending the evacuation zone around the two Fukushima nuclear plants from 10km to 20km, according to local media.
Well, judging from past nuclear accidents (Chernobyl, 3 mile island), I would: 1.) Not trust the government, the plant operator, the plant designer, hell anyone remotely involved. They always downplay whatever is really going on to prevent panic (or divert blame) 2.) Get as far away as possible, preferably in the opposite direction of prevailing winds.
Government spokesman says the nuclear reactor container at the Fukushima-Daiichi plant has not been damaged, and the level of radiation has dropped following the explosion earlier on Saturday, AFP reports
but as you put it, can we believe this anymore? Yesterday everything was supposed to be under control.
Would be interesing to hear from communication professionals what they think about this.
Re: Video of reactor 1 at Fukushima plant
#67http://news.google.com/news/more?ncl=d_LFixACgsQEvVMNHMag3MA... There is almost guaranteed significant radiation release. quote from slashdot: The outer walls of the Reactor 1 building have partially blown off, leaving only what looks like a steel frame. NHK is saying that a sensor within 5km of the plant is detecting radiation levels approaching 1015 microsieverts - that is apparently a year's worth of radiation exp…
This guy from that thread seems to know his stuff:
But who knows...
Re: Video of reactor 1 at Fukushima plant
#68Kyodo News agency said radioactive caesium had been detected near the site, quoting the Japanese nuclear safety commission. Radioactivity rose 20-fold outside, reports said. (EDIT: this was before the explosion) The plant "may be experiencing nuclear meltdown", Kyodo and Jiji reported before the explosion, while public broadcaster NHK quoted the safety agency as saying metal tubes that contain uranium fuel may have m…
Is 20-fold increase in radioactivity actually hazardous? I was under the impression dangerous levels of radiation are many, many times above normal background radiation and typical 'acceptable' levels of exposure. See http://www.geigercounters.com/Danger.htm for example. Occupational acceptable exposure is 25x that of non-occupational.
The average radioactive dose a person gets per year is about 3,6 to 5 milliSievert a year (for Belgium) of which 2,6 mSv from natural sources, 0,95mSv from medical examinations and 0,05mSv from industry (of which 0,01mSv due to nuclear power)
So when they say around the reactor the dose in an hour is about the same as you get a year, then this is about equivalent to two scans in a hospital.
Note: this is talking about low levels where the only influence radiation has is increasing the chance of cancer. If there are very high doses >100mSv involved, there will be direct radiological damage which can be strongly compared to damage from burning.
Re: Video of reactor 1 at Fukushima plant
#69http://twitter.com/#!/martyn_williams/status/465371589153914...
The reactor DID NOT explode. HN is becoming a bit sensationalist today.
Edit: http://en.wikipedia.org/wiki/Boiling_Water_Reactor_Safety_Sy...
Basically, this bit:
The reactor building (the shield wall/missile shield) is also made of steel-reinforced, pre-stressed concrete 0.3 m to 1 m (1–3 feet) thick.
The concrete surrounding the building is now gone (due to excess pressure).
Second edit:
[6:54 a.m. ET, 8:54 p.m. Tokyo] The explosion at Japan's Fukushima nuclear plant was not caused by the nuclear reactor but by "water vapor that was part of the cooling process," Chief Cabinet Secretary Yukio Edano said Saturday. He said no harmful gases had been emitted by the explosion.
[6:44 a.m. ET, 8:44 p.m. Tokyo] Japanese Prime Minister Naoto Kan confirms that the evacuation area around the Fukushima Daiichi nuclear plant has been increased to 20 kilometers. But no one has been harmed by radiation, he says.
Third edit (from the BBC):
1218: It seems clear now from Mr Edano's comments that the nuclear plant building that was blown apart earlier did house a reactor, but the reactor was protected by its metal casing.
1216: Government spokesman Yukio Edano says the pressure as well as the radiation at the Fukushima-Daiichi nuclear plant has fallen following this afternoon's explosion.
So the "explosion" has actually helped the situation.
Fourth edit: Looking like Sendai just got hit with another earthquake. I hope that hasn't caused any more damage to the reactor. http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/us...
Fifth edit: From http://twitter.com/#!/norishikata
"Blast was caused by accumulated hydrogen combined with oxygen in the space between container and outer structure. No damage to container."
"Trend of μ Sv/h of Unit 1 this afternoon. 1,015(at 15:29), blast (15:36), 860(15:40), 70.5 (18:58). After blast, radioactive level lowered."
"TEPCO's efforts to depressurize the container was successful. Additional measures are now taken tonight using sea water and boric acid."
Things are looking up.
Re: Video of reactor 1 at Fukushima plant
#70Earlier quoted context omitted.
"This is starting to look a lot like Chernobyl" Walt Patterson, an associate fellow with Chatham House, has told the BBC after seeing pictures of the explosion at the Fukushima-Daiichi nuclear plant. "The nuclear agency says that they have detected caesium and iodine outside the unit, which certainly indicates fuel melting at the very least," he says. "Once you have melting fuel coming into contact with water, that w…
This is quite different from Chernobyl, which didn't even have a proper confinement wall. It's unlikely that it can get as bad as Chernobyl was.
Some reports[1] indicate radioactive iodine and cesium are being detected at monitoring stations. How could that happen if confinement hadn't failed? (fuel rods melting, containment failure of the reactor vessel and/or primary coolant loop, and the obvious lack of a containment building at this point)
Based on the description of two-stage containment for BWRs at wikipedia[2], and the video, if that's the containment strategy at Fukushima, it seems the drywell containment structure blew up, since steam being vented into a pool of water shouldn't cause a visible breach.
[1] http://e.nikkei.com/e/fr/tnks/Nni20110312D12JF520.htm
[2] http://en.wikipedia.org/wiki/Containment_building#Boiling_wa...