Terremoto in Giappone

[blackdevils]

non che TEPCO sia l'azienda + trasparente al mondo comunque...

Mi fido più di loro, che dell'agenzia francese che sta gridando all'apocalisse da giorni. Son 2 giorni che dicono "livelli alti di radiazioni a Tokyo", quando poi il team italiano ha detto che Roma è più radioattiva...

[metalalby]

Romani fate causa al comune.

[dead man drinking]

Mi fido più di loro, che dell'agenzia francese che sta gridando all'apocalisse da giorni. Son 2 giorni che dicono "livelli alti di radiazioni a Tokyo", quando poi il team italiano ha detto che Roma è più radioattiva...

La Tepco falsificava i dati sulla sicurezza di Fukushima. Nel 2002 il presidente e 4 top manager della compagnia energetica rassegnarono le dimissioni per lo scandalo: ma di nuovo nel 2006 il governo chiese la revisione dei dati dichiarati perché palesemente falsi. E ancora ammissioni di falsificazione nel 2007. La centrale di Fukushima era a rischio dal 1985.

La Tepco (Tokyo Energy Power Company) è la principale compagnia energetica del Giappone. Nel 1971 aveva acceso il primo reattore - da 460 MW - della centrale nucleare di Fukushima Daiichi, quello che oggi è a rischio disastro atomico. Ma nel corso della sua storia il gigante nipponico ha avuto parecchi grattacapi da Fukushima, come riporta anche la CNN.

Nel 2002 scoppia infatti uno scandalo sulla sicurezza della centrale: il presidente della società e quattro dirigenti rassegnano le dimissioni dopo aver ammesso di aver falsificato i dati delle ispezioni della Iaea e di aver taciuto la realtà per oltre dieci anni. Le ispezioni dell'Agenzia per la sicurezza atomica giapponese (il Nisa), infatti, avevano rilevato negli anni '80 e '90 valori fuori norma nella radioattività della centrale di Fukushima e altri 12 impianti simili, in seguito a diversi terremoti. I dirigenti avevano coperto tutto falsificando i documenti, e il governo dell'allora premier Junichiro Koizumi aveva fatto finta di niente. (Corriere della sera, 30 agosto 2002).

Non basta. Nel 2006 il governo giapponese guidato da Shinzo Abe chiede alla Tepco di ricontrollare i dati storici reali, dopo una nuova ammissione di colpevolezza da parte della compagnia: la temperatura di raffreddamento della centrale di Fukushima, tra il 1985 e il 1988, era stata nascosta perché al di fuori dei valori regolamentari. I rischi erano cresciuti, nessuno ammetteva di quanto. E nel 2007, la stessa Tepco torna ad ammettere, su pressione dei media e dell'opinione pubblica, di aver riscontrato nuove falsificazioni nei dati storici della centrale incriminata.

I controlli sono stati falsati per anni. Chi doveva controllare ha preferito coprire piuttosto che intervenire. L'effetto è ora sotto gli occhi di tutti, ma chi si assumerà le responsabilità del passato?

[blackdevils]

Direi che la situazione ad oggi sia diversa. Un conto problemi minori o ispezioni possono essere insabbiate, ma ad oggi credo proprio che non ci sia possibilità di dire cose inesatte visto anche il coinvolgimento degli USA.

[chaos]

Direi che la situazione ad oggi sia diversa. Un conto problemi minori o ispezioni possono essere insabbiate, ma ad oggi credo proprio che non ci sia possibilità di dire cose inesatte visto anche il coinvolgimento degli USA.

beh oddio quello che possono fare i privati quando si tratta di occultare un disastro e' senza limiti....
e si gli usa di solito in questo sono bravissimi quindi in qualita' di garanti non e' che siano proprio il massimo.

[blackdevils]

beh oddio quello che possono fare i privati quando si tratta di occultare un disastro e' senza limiti....
e si gli usa di solito in questo sono bravissimi quindi in qualita' di garanti non e' che siano proprio il massimo.

Ma non possono con gli occhi puntati del mondo addosso. Dai. Che fanno, continuano a dare il livello 4 e poi magari tra 12 ore il reattore salta?

[dodv]

ke è successo nelle ultime ore??ho sentito ke c'è stato 1 incendio nel reattore 4..le cose si aggravano di brutto vero?

[chaos]

Ma non possono con gli occhi puntati del mondo addosso. Dai. Che fanno, continuano a dare il livello 4 e poi magari tra 12 ore il reattore salta?

beh dipende il reattore dubito che salti, il problema e' la contminazione di acqua e aria e il fallout nucleare relativo alle esplosioni che ci sono gia' state, tutta roba per cui bisognera' aspettare qualche decina di giorni (ma forse anche qualcosa di piu') e gia' fra 20 giorni non se li inculera' piu' nessuno come al solito.

[Lord Of Darkn3ss]

una domanda stupida:

in condizioni normali (senza tsunami o terremoti), le persone che vivono nei pressi di una centrale nucleare corrono rischi?

motivate la risposta magari

[Fait]

una domanda stupida:

in condizioni normali (senza tsunami o terremoti), le persone che vivono nei pressi di una centrale nucleare corrono rischi?

motivate la risposta magari

Naturalmente non credo si possa costruire una centrale nucleare in mezzo ad una città (neanche una normale centrale elettrica, volendo), però non c'è nessun pericolo se funziona come si deve.

[MassiveMolecule]

una domanda stupida:

in condizioni normali (senza tsunami o terremoti), le persone che vivono nei pressi di una centrale nucleare corrono rischi?

motivate la risposta magari

http://www.scientificamerican.com/artic ... lear-waste

The result: estimated radiation doses ingested by people living near the coal plants were equal to or higher than doses for people living around the nuclear facilities. At one extreme, the scientists estimated fly ash radiation in individuals' bones at around 18 millirems (thousandths of a rem, a unit for measuring doses of ionizing radiation) a year. Doses for the two nuclear plants, by contrast, ranged from between three and six millirems for the same period. And when all food was grown in the area, radiation doses were 50 to 200 percent higher around the coal plants.

McBride and his co-authors estimated that individuals living near coal-fired installations are exposed to a maximum of 1.9 millirems of fly ash radiation yearly. To put these numbers in perspective, the average person encounters 360 millirems of annual "background radiation" from natural and man-made sources, including substances in Earth's crust, cosmic rays, residue from nuclear tests and smoke detectors.

[ZX24]

Rai News ha parlato di questo sito ("concerned scientists", http://www.ucsusa.org) che parrebbe discutere i dati della TEPCO:

Spent Fuel Pools at Fukushima
| by David Wright | nuclear power | nuclear power safety | Japan nuclear |

Because of their high radioactivity, fuel rods continue to produce very significant heat even after they are no longer useful for generating electricity and are removed from the reactor core. Such “spent fuel” rods need to be continually cooled for many years to prevent them from heating to a level where they would suffer damage.
To cool the rods after they are removed from the reactor core, they are placed on racks in a spent fuel pool that circulates cooled water around them. This water is circulated by pumps that are run using electricity from the power grid. Typically these pumps do not have backup power from deisel generators or batteries, so if power from the grid is interrupted, as it is in the case of the Japanese earthquake, they will stop operating.
Once the cooling pumps stop, the water in the spent fuel pools will begin to heat up and will eventually start to boil off. The pools are typically 45 feet deep with the fuel rods stored in the lower 15 feet of the pool, so 30 feet of water would have to boil off before exposing the rods. That could take several days, so this issue may only be appearing now.
The pool at Fukushima Dai-Ichi Unit 4 is a particular problem since the fuel rods in it were only removed from the reactor core during a refueling of the reactor in December 2010. Therefore, they still have a very high level of radiation and are generating more heat than the spent fuel at the other reactors at the Dai-Ichi site.

The spent fuel pools for the Dai-Ichi reactors are located on an upper floor in the reactor building (see red circle in figure). The pools are outside the primary containment of the reactor, but inside the reactor building, which is the secondary containment. Typically any radioactivity released from the pool will be contained by the reactor building, which is maintained at less than atmospheric pressure so air flows into the building rather than out. The air in the building is filtered to remove the radioactivity before it is released outside.
As the water in the pool heats up and evaporates, the vapor will carry some radiation with it. This includes tritium and radioactive particles in the water.
If the water level in the pool drops low enough to expose the spent fuel, the fuel rods can suffer the same kinds of damage as fuel in the reactor core that is expose. If only a small length of the rods is exposed, they will get hot enough to create steam, but the steam flowing along the exposed surface of the rod will cool it enough that the rod’s cladding will not reach the high temperature required to react with the steam and create hydrogen.
Once the water has dropped low enough to expose several feet of the length of the fuel rods, they can become hot enough that the zirconium cladding of the rods will react with the steam and release hydrogen.
Tokyo Electric Power Company (TEPCO) has said there was a hydrogen explosion that damaged the Unit 4 reactor building on Tuesday morning in Japan (Monday afternoon U.S. time), reportedly blowing a 26-foot wide hole in the side of the building. If this explosion was due to hydrogen, that hydrogen very likely came from the spent fuel since there is no other clear source (this reactor was not operating when the earthquake hit). And if the spent fuel produced the hydrogen, that indicates that the water level in the spent fuel pool must have been low enough to have exposed a significant fraction of the fuel rods.
Shortly after that—at 9:38 am Tuesday (8:38 pm EDT Monday)—TEPCO discovered a fire on the fourth floor of the building in the spent fuel pool, which reportedly burned for three hours. That fire may have been the oxidation of the zirconium cladding, as it was continuing to produce hydrogen.
The other effect of heat damage to the fuel rods is that radioactive gases such as iodine-131 and cesium-137, which are produced in the fuel during the operation of the reactor, can be released. The hole in the secondary containment at Unit 4 means that any emissions from the spent fuel will be vented directed to the outside.
If water cannot be added to the pool, or if the pool has been damaged and is leaking, the fuel may remain uncovered. The exposed fuel can get hot enough to melt, depending on how long it has been out of the reactor. If the fuel melts, it would release significant additional radioactivity into the air.
This same scenario could occur at Units 5 and 6 if the water in the spent fuel pools is not replenished, although the fuel there has apparently been in the pools longer and is not as radioactive as at Unit 4. For rods that have been in the pool for long enough, their decay heat will have dropped sufficiently that they will not undergo the same rapid oxidation as newer fuel rods will, and would not produce as much hydrogen.
Thus, depending on the age of the spent fuel in Units 5 and 6, there may be less hydrogen produced if the water level in the spent fuel pool drops. There may still be enough heat to damage the fuel and release radioactive gases, but if the secondary containment is not damaged by a hydrogen explosion, that gas may not be released to the atmosphere.
If mechanisms to fill the pool at Unit 4 are broken, or if there is a need to repair the pool, it will be difficult to get workers close enough to do this. If spent fuel has been in the pool for a relatively short time, even if the water level is at the top of the fuel rods, the radiation dose to someone at the railing of the pool would give them a lethal dose in well under a minute. This would explain why there have been reports of requests to use helicopters to deliver water to the pools. However, it appears that this is not a practical way of delivering water.



http://allthingsnuclear.org/tagged/Japa ... %2F2011-pm

[MassiveMolecule]

Ed ecco che gli avvoltoi si precipitano a lucrare! Yeah!

http://news.discovery.com/human/japanes ... 10315.html

the wake of the Japanese tsunami and Saturday's explosion at the Fukushima nuclear plant north of Toyko, nearly a quarter of a million people have been evacuated from the area. The immediate tsunami danger has passed, but there is the lingering threat of radiation exposure.

Health officials are encouraging residents to seek temporary shelter and take iodine pills to deal with the potentially deadly consequences of nuclear radiation. The iodine tablets are useful because they protect the thyroid from absorbing excessive radiation in the form of radioactive iodine.

Other than that, there are no specific pills that are recommended for the public in this circumstance. But that doesn’t mean that alternative medicine promoters aren’t offering “help.”

An e-mail titled “Guidelines for Homeopathic Prevention and Treatment of Radiation Sickness and Poisoning” circulated by an Australian group called Homeopathy Plus states:

“(R)adioactive material carried by wind and air currents may spread contaminated material to neighboring islands and countries. For all concerned, there are protective steps that can be taken with homeopathy. Key remedies that have been used either in research or historically to prevent or treat radiation poisoning include the following: Cadmium iodide; Cadmium-sulph; Phosphorus; Strontium-carbonicum; and X-ray. If at risk of radiation exposure, any one of the above remedies may be taken as an emergency response, three times a day in a 30C potency. Do not exceed 6 doses without guidance from your homeopath.”
The e-mail has circulated widely, though it’s not clear if any Japanese victims have turned to homeopathy.

SLIDE SHOW: Top 5 Cities on Faults

The advice to use homeopathic treatments on radiation victims is irresponsible and dangerous. Homeopathic preparations have no active ingredients and are therefore worthless. Homeopathic medicines are often so literally watered-down that they don't contain a single molecule of the original medicine or substance: The patient is drinking nothing but water.

Last year, the British Science and Technology Select Committee conducted a comprehensive study into whether homeopathy has any scientific validity. The report was devastating: "Homeopathy is not efficacious, and explanations for why homeopathy would work are scientifically implausible."

Phil Plait, a writer for the Bad Astronomy website (devoted to science-based public policy), said he was concerned that people might take the recommendations from Homeopathy Plus seriously.

"I notice they recommend a 30C dose of X-rays. X-rays are just a form of light," he told Discovery News. "I don't see how zapping water with X-rays and then diluting it gives you anything but what you started with: water. And using that to treat cancer is maybe not your best bet."

This is not the first time that unproven and worthless medical treatments have been offered to natural disaster victims. In the aftermath of last year’s devastating earthquakes in Haiti, many people, including faith healers from the Church of Scientology and homeopathic practitioners, offered ineffective medical “cures” to the sick, wounded and dying.

[blackdevils]

Penso che le aziende che producono iodio si stiano sfregando le mani...

[MassiveMolecule]

La situazione è critica ma relativamente stabile.