Tópico: O futuro da energia nuclear após o desastre no Japão.

[SnowRaptor]

Isso que eu disse.

Foi projetada para um terremoto de 8.2. O terremoto que a atingiu foi de 8.9, portanto cerca de 5 vezes mais intenso que o projetado, mas os vários níveis de redundância e segurança estão permitindo a usina aguentar por dias depois do desastre, dando tempo dos técnicos efetuarem uma série de medidas de contingência e minimizando os danos à população e procurando minimizar os danos ao ambiente.

[HeadLikeAHole]

Errei na comparação das magnitudes, o terremoto que ocorreu foi 5 vezes mais intenso que o que a usina foi projetada pra suportar e não 7 como eu escrevi acima, mas a ideia continua.

continuo sem entender.  Não foi projetado para 8.2 ?  O terremoto foi de 8.9

A escala é logarítmica.

[Pedrão]

Errei na comparação das magnitudes, o terremoto que ocorreu foi 5 vezes mais intenso que o que a usina foi projetada pra suportar e não 7 como eu escrevi acima, mas a ideia continua.

continuo sem entender.  Não foi projetado para 8.2 ?  O terremoto foi de 8.9

A escala é logarítmica.

caraca, mas mesmo na escala logaritmica, de 8.2 para 8.9 dá um crescimento de 5 vezes ?

[HeadLikeAHole]

10^0.7 = 5.011872336

[Pedrão]

10^0.7 = 5.011872336

mas que gente burra.  Foram escolher logo a base logaritmica decimal.

Se estivessem escolhido a base neperiana, os terremotos seriam bem mais fraquinhos, e esse do Japão não seria nem o dobro do que tinham projetado para a usina nuclear aguentar:

2,7^0,7 < 2

 

[Feynman]

Se estivessem escolhido a base neperiana, os terremotos seriam bem mais fraquinhos

 

[Pedrão]

Se estivessem escolhido a base neperiana, os terremotos seriam bem mais fraquinhos

 

Feynmann, voce gostou da piada, ou interpretou a frase ao pé da letra ?

  ... se foi ao pé da letra, eu desconfiava que alguém iria faze-lo 

 Sempre tem um ... ah... deixa pra lá, senão o Unknown vai querer me aplicar um cartão amarelo...

[Feynman]

Gostei da piada, naturalmente! 
Se alguém interpretar sua frase ao pé da letra, eu me mato!

[Pedrão]

Para os fraquinhos em matematica, e não entenderam:

Se a escala fosse neperiana, a diferença no valor projetado e valor real seria maior que 0,7.  Por exemplo, teriamos 8.2 e 9.85, de forma que:

2,7^1,65 = 5

Pois é claro que uma expressão matematica não pode mudar a intensidade de um terremoto 


Apesar de que, na Fisica Moderna, equaçoes produzem efeitos físicos.  Por exemplo, segundo a Fisica Moderna, a equaçao de Maxwell pode gerar um raio de luz.

Voce duvida ?

Então faça a experiencia.  Escreva a equaçao de Maxwell no papel, e verá que um raio de luz se formará, assim que voce terminar de escrever a equaçao.   

[SnowRaptor]

[Buckaroo Banzai]

<a href="http://www.youtube.com/v/nRXDYC3TnG4" target="_blank" class="new_win">http://www.youtube.com/v/nRXDYC3TnG4</a>

[Buckaroo Banzai]

A energia nuclear provavelmente salvou mais vidas do que tirou, mesmo incluindo esses desastres, se você compara com as alternativas, e pode vir a salvar ainda mais vidas.

[...] It’s worth noting that the authors consider only deaths and exclude from the model serious health crises such as heart failure, bronchitis and other respiratory problems; including these problems would further weaken the case for fossil fuels. The study also excludes aspects of nuclear power that cannot be easily quantified, such as deaths from nuclear proliferation.

The results are quite clear. In the 2000-2009 period alone nuclear power may have prevented an average of 76,000 deaths. This is an average and the range is quite large, but even the lower limit runs into the tens of thousands. For countries like Germany which have cut back on nuclear, the range of deaths is naturally higher. This is a result that Japan’s current leaders should take to heart.

What is even more starkly clear is that the number of deaths caused by nuclear power is far lower than those saved by it; in fact there’s scant comparison. [...]

The conclusions of the study are quite unambiguous. Even assuming uncertainties, nuclear power has saved at least hundreds of thousands of lives in the past forty years, and possibly millions. This is in stark contrast to the small number of lives lost in only one catastrophic nuclear accident. There are many more millions that would be lost if countries were to embark on a nuclear-free future replaced by fossil fuels. Natural gas might be a reasonable bridge to this future but it’s clear that it cannot be a sustainable one. It would take “heroic” efforts (in the words of the International Energy Agency) to replace all the nuclear power in the world with renewables in the next forty years. New generations of nuclear reactors like the molten salt and pebble bed reactors promise to make nuclear energy even more safe, efficient and cheap. Even Bill Gates is investing in a novel reactor design. The verdict is staring us in the face; we ignore energy from the atom at our own peril, and at the potential cost of a staggering number of lives from our children and grandchildren’s generation. It’s not the kind of legacy we want to be remembered for.

http://blogs.scientificamerican.com/the-curious-wavefunction/2013/04/02/nuclear-power-may-have-saved-1-8-million-lives-otherwise-lost-to-fossil-fuels-may-save-up-to-7-million-more/

[Muad'Dib]

A energia nuclear provavelmente salvou mais vidas do que tirou, mesmo incluindo esses desastres, se você compara com as alternativas, e pode vir a salvar ainda mais vidas.

[...] It’s worth noting that the authors consider only deaths and exclude from the model serious health crises such as heart failure, bronchitis and other respiratory problems; including these problems would further weaken the case for fossil fuels. The study also excludes aspects of nuclear power that cannot be easily quantified, such as deaths from nuclear proliferation.

The results are quite clear. In the 2000-2009 period alone nuclear power may have prevented an average of 76,000 deaths. This is an average and the range is quite large, but even the lower limit runs into the tens of thousands. For countries like Germany which have cut back on nuclear, the range of deaths is naturally higher. This is a result that Japan’s current leaders should take to heart.

What is even more starkly clear is that the number of deaths caused by nuclear power is far lower than those saved by it; in fact there’s scant comparison. [...]

The conclusions of the study are quite unambiguous. Even assuming uncertainties, nuclear power has saved at least hundreds of thousands of lives in the past forty years, and possibly millions. This is in stark contrast to the small number of lives lost in only one catastrophic nuclear accident. There are many more millions that would be lost if countries were to embark on a nuclear-free future replaced by fossil fuels. Natural gas might be a reasonable bridge to this future but it’s clear that it cannot be a sustainable one. It would take “heroic” efforts (in the words of the International Energy Agency) to replace all the nuclear power in the world with renewables in the next forty years. New generations of nuclear reactors like the molten salt and pebble bed reactors promise to make nuclear energy even more safe, efficient and cheap. Even Bill Gates is investing in a novel reactor design. The verdict is staring us in the face; we ignore energy from the atom at our own peril, and at the potential cost of a staggering number of lives from our children and grandchildren’s generation. It’s not the kind of legacy we want to be remembered for.

http://blogs.scientificamerican.com/the-curious-wavefunction/2013/04/02/nuclear-power-may-have-saved-1-8-million-lives-otherwise-lost-to-fossil-fuels-may-save-up-to-7-million-more/

Mas aqui se comparou o número de mortes que foram evitadas se as usinas nucleares fossem substituidas por combustível fóssil. Uma comparação hipotética.

Poderia ser feita uma comparação relacionando o número de mortes dos acidentes, incluindo as advindas do desastre de Chernobyl por motivos de doença, com energias renováveis que não estão recebendo apoio financeiro suficiente para para a evidente e já a muito tempo prevista, substituição de fonte de energia.

O desastre de Fukushima ainda está muito longe de ser história. Semana passada os técnicos da Tepco identificaram um vazamento radioativo de grandes proporções e, ao que parece, esses vazamentos são uma constante. Eu não sei qual a dinêmica de dispersão de vazamentos radioativos no oceano, mas o Japão, culturalmente dependente do mar para a alimentação do seu povo, certamente terá problemas no futuro.

[Buckaroo Banzai]

O texto diz que o artigo lida com os casos de desastres e suas conseqüências:

[...] As the report notes, even the worst nuclear accident in history (Chernobyl) caused about 40 deaths; these include 28 immediate responders and about 15 deaths caused among 6000 victims of excess cancers (it’s always very difficult to detect statistically significant excess cancers in the presence of a high natural background rate). There have been no deaths attributable to the Three Mile Island accident. And while the verdict on Fukushima is still not definitive, the latest report on the accident predicts no direct deaths and a much lower exposure to radiation for the surrounding population than that purported to lead to fatal cancers. The bottom line is that, even assuming pessimistic scenarios, the number of deaths caused by nuclear power is a minuscule fraction of those lives which were saved by nuclear power replacing fossil fuels.

Nuclear-free projections for the next four decades look even more dire. The authors estimate between 4 and 7 million deaths for the “All-Coal” scenario and between 420, 000 – 680, 000 deaths for an “All-Gas” energy policy. [...]

http://blogs.scientificamerican.com/the-curious-wavefunction/2013/04/02/nuclear-power-may-have-saved-1-8-million-lives-otherwise-lost-to-fossil-fuels-may-save-up-to-7-million-more/

Eu não sei quanto a contaminação do mar. Parece que a vida natural em Chernobyl se recuperou mais rapidamente do que se esperava. Acho que no mar é ainda mais rápido.

[...]  Certainly there is a danger to wildlife very close to the site, Fisher said. It's also a good idea not to eat the fish and other marine animals from that area. But on the other hand, you don't have to go very far from the site before the levels drop to well below the natural levels of radioactivity in sea water.

"I'm not in favor (of radiation leaks) and I wish it hadn't happened, but we should respond in a measured way," said Fisher.

And that means keeping the radiation levels in perspective. While the Fukushima cesium has been found in blue fin tuna that have crossed the Pacific, the radiation from that cesium is far less than that of the naturally occurring polonium in the oceans and in fish. [...]

http://news.discovery.com/earth/oceans/will-fukushima-mutate-sea-life-130828.htm

Parece que o maior problema agora é o vazamento para lençóis freáticos. Estão planejando ou executando uma contenção disso com congelamento permanente dessa água em um dado perímetro, bem impressionante.

http://www.technologyreview.com/news/518801/how-the-fukushima-ice-barrier-will-block-radioactive-groundwater/