Video of reactor 1 at Fukushima plant
youtube.com
youtube.com
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 exposure
EACH HOUR
People in the danger zones are being told to cover faces
with wet towels, avoid eating vegetables and other fresh foods,
and refrain from drinking tap water.(EDIT) More from Walt Patterson of Chatham House. He says the presence of the radioactive caesium in the surrounding area does not pose a huge threat to public health in the immediate aftermath of the explosion. "What would be serious is if there was an explosion or fire that lifted this stuff high in the air, meaning it could get carried over a wide area."
The containment referred to in this case is a vessel made of a feet-thick layer of concrete surrounding the reactor. This is the final defense if a fuel meltdown occurs: its job is to contain the burning fuel and prevent it from being exposed to the environment. [1]
What the GP was referring to is that there was no such vessel at Chernobyl, which was a very old reactor design. Modern reactors are surrounded in such vessels. [2]
[1] http://en.wikipedia.org/wiki/Containment_building
[2] Here's some information about the reactor design at Chernobyl: http://en.wikipedia.org/wiki/RBMK#Containment
Another interesting read is the story of the Russian engineers who prevented an explosion at Chernobyl by diving into the pool of water beneath the reactor and opening the drainage valves: http://en.wikipedia.org/wiki/Chernobyl_disaster#Steam_explos...
But if the outer building which is supposed to contain everything else blows up - that's not exactly the best case is it?
You could think about the outer building as keeping the rain out, and possibly aeroplanes to some extent. It is not the critical last defence against stuff happening in the reactor, the containment building is. You can bet that the japanese army is keeping any possible threats out of there.
I also read that on TMI a similar hydrogen explosion occurred but it was contained by containment dome.
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...
This is just built-up decay heat and chemical reactions.
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.
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.
Give me one example of when the government, the plant operator, the plant designer knowingly lied about the situation.
Give me one example of someone who was harmed by Three Mile Island which had a full meltdown with containment. (Chernobyl is irrelevant, it did not have containment.)
Really? People with reputations at stake rarely or never spin information that minimizes impact to their reputations? People with dangerous information rarely or never, rightly or wrongly, minimize the impact of that dangerous information for concern over spreading panic?
Next you'll tell me POTUS never lies, Congress is looking out for our best interests, and nuclear power is essentially 100% safe.
> Give me one example of someone who was harmed by Three Mile Island which had a full meltdown with containment.
http://pittsburgh.about.com/cs/history/a/tmi.htm
Quote: A new analysis of health statistics in the region conducted by the Radiation and Public Health Project has, however, found that death rates for infants, children, and the elderly soared in the first two years after the Three Mile Island accident in Dauphin and surrounding counties.
http://www.unc.edu/news/archives/feb97/wing.html
Quote: Exposure to high doses of radiation shortly after the nuclear accident at Three Mile Island may have increased cancer among Pennsylvanians downwind of the plant, scientists at the University of North Carolina at Chapel Hill say.
That's two.
> Chernobyl is irrelevant
Excellent news.
--
Another angle is that the "people that know what they're talking about" very often don't know what they're talking about, particularly in the minutes/hours/days following emergency conditions. TMI timeline:
Scranton held a press conference in which he was reassuring, yet confusing, about this possibility, stating that though there had been a "small release of radiation,... no increase in normal radiation levels" had been detected. These were contradicted by another official, and by statements from Met Ed, who both claimed that no radiation had been released.[21] In fact, readings from instruments at the plant and off-site detectors had detected radiation releases, albeit at levels that were unlikely to threaten public health as long as they were temporary, and providing that containment of the then highly contaminated reactor was maintained.
But who knows...
Right now, my main concern is the release of Caesium-137. If that has been detected, then there is a solid chance that the core has been at least partially exposed. Caesium-137 has a half-life of 30 years and is a gamma emitter. It's also water-soluble. Not a good combination.
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.
A (what I guess) is a similar explosion happened in the reactor building in TMI, and the risk of an explosion such as this seems to be well known. The reactor building was probably prepared to absorb the explosion away from the containment structures, making it look much worse than it is.
http://uvdiv.blogspot.com/2011/03/some-links-on-fukushima-da...
"At this point, there has been no major change to the level of radiation leakage outside (from before and after the explosion), so we'd like everyone to respond calmly," Edano said."
http://www.reuters.com/article/2011/03/12/japan-quake-reacto...
Now they are going to flood the reactor container with seawater.
"Edano said due to the falling level of cooling water, hydrogen was generated and that leaked to the space between the building and the container and the explosion happened when the hydrogen mixed with oxygen there."
It looks like they're about to use this:
Low Pressure Coolant Injection System (LPCI)
Then this:
Standby Liquid Control System (SLCS)
http://en.wikipedia.org/wiki/Boiling_Water_Reactor_Safety_Sy...
Looks like they've given up saving the reactor.
-----
1. Hydrogen explosion occurred at 15:36 between containment and reactor building of Fukushima Daiichi unit 1. Walls of reactor building were blown out or damaged.
2. It was confirmed that unit 1 containment integrity was maintained.
Explosion was not inside the containment as it is inert.
3. Radiation level at the Fukushima Daiichi site border once increased when containment vent was conducted and reached 1,015 micro Sv per hour around the time when explosion occurred; however, the radiation level turned to decrease after the explosion down to 860 at 15:40 and 70.5 micro Sv per hour at 18:58.
4. Government has agreed to TEPCO decision to fill the entire containment up with sea water. The filling sea water will contain boron. TEPCO started the work for filling up at 20:20.
(It just reads like one of those understated but extremely important bits you find in these sorts of alerts :-| )
In a PWR you add it into the water as a way to moderate the reaction, but in a BWR (like the reactor 1 in Fukushima Daiichi) you only add it as a last resort, since it is incredibly hard to clean out of the system.
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 melted.(AFP)
http://www.guardian.co.uk/world/blog/2011/mar/12/japan-tsuna...
See http://www.geigercounters.com/Danger.htm for example. Occupational acceptable exposure is 25x that of non-occupational.
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.
Exposure to 1.015 mSv / hour for a year would give a dose equivalent of 8.9 Sv - the excess relative risk of cancer for low dose chronic radiation exposure is about 0.97 per Sv - so the exposure to that level for a year would drastically increase cancer risk.
Obviously, people won't be allowed into the areas where radiation levels were that high.
I saw a report of a worker acutely exposed to >100 mSv; that single event would be enough to increase that worker's lifetime risk of cancer by about 10%.
http://www.tepco.co.jp/en/press/corp-com/release/11031219-e....
(I am not an engineer)
http://en.wikipedia.org/wiki/Boiling_Water_Reactor
It lacks the safety mechanisms of an abwr. Namely even after the control rods are deployed, heat can continue to build up. Hence the plant requires forced cooling, in this case provided by diesel and electric pumps. After the earthquake the diesel pumps failed and cooling was effected by battery power. While the government rushed in new diesel generators, they were not installed in time to prevent the build up of pressure resulting in this explosion.
Agency officials said a team of National Institute of Radiological Sciences detected cesium, a radioactive substance contained in nuclear fuel rods, near the No. 1 reactor of the No. 1 nuclear plant, leading them to suspect nuclear fuel rods in the reactor began melting amid the high temperatures.
The nuclear safety agency said in the afternoon that the level of cooling water in the No. 1 reactor likely had dropped to 1.7 meters below the top of nuclear fuel rods, leading officials to suspect that about half of the rods' length had been exposed.
Reactor meltdown feared / Quake disabled Fukushima N-plants' cooling systems
"A portion of the reactor's fuel rods, which create heat through a nuclear reaction, had become exposed due to the cooling-system failure. The spokesman for Tepco said 1.5 meters of the 4.5 meter long fuel rods were exposed. It was unclear Saturday afternoon whether the water added by workers had re-covered the rods."
http://online.wsj.com/article/SB1000142405274870355540457619...
http://news.ycombinator.org/item?id=2316851
It's going to take a couple days for any nuclear reactor to burn off decay heat.
Area of a 20km circle is 1257 km2
Assuming they go to 30km or 50km next:
Area of a 30km circle is 2827 km2
Area of a 50km circle is 7854 km2
Can anyone with more knowledge and experience of this confirm?
More info: http://www.world-nuclear-news.org/RS_Battle_to_stabilise_ear...
This actually happened at Three Mile Island, and there was a hydrogen explosion in the containment building there (which did not break).
(I am not an engineer)
Right? Has anybody found any documents if Japan has been notified or warned about these backup systems of these plants? It sound like a design failure to me. (I know nothing about nuclear power plants)
The main steel structure is still standing, and the expert in the studio was saying something like there still is a chance of the 3-Mile Island like scenario. That is that the nuclear material is still contained within the core structure.
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).
[1] http://en.wikipedia.org/wiki/Myocardial_infarction [2] http://en.wikipedia.org/wiki/Stroke [3] http://en.wikipedia.org/wiki/List_of_causes_of_death_by_rate...
http://img405.imageshack.us/img405/3245/8m6k8n7f8q7z7.jpg
US West Coast gets the fallout cloud in 10 days.
edit: BBC says it's an explosion but article is completely devoid of details: http://www.bbc.co.uk/news/world-asia-pacific-12720219
http://en.wikipedia.org/wiki/File:2011-03-12_1800_NHK_S%C5%8...
http://en.wikipedia.org/wiki/2011_Sendai_earthquake_and_tsun...
http://upload.wikimedia.org/wikipedia/commons/e/e8/Fukushima...
The longer, rectangular buildings on the seaside are the turbine halls, and the square buildings next to them (in the inland direction) are the containment buildings.
That PDF has a schematic of the containment building on page 4. The "MARK-I" image corresponds to the Fukushima I-1 building.
from, respectively,
Madgi Ragheb, UIUC https://netfiles.uiuc.edu/mragheb/www/NPRE%20457%20CSE%20462...
Cuz the USA offered to send emergency help.
Imagine the USA team going over and finding nothing really happened, an entire hoax.
This bombing was crafted to short the stock markets.
It's pitiful what the rich do for their market gains.