Arquivo da tag: Energia nuclear

The Art of Pondering Distant Future Earths (MIT Press Reader)

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Stretching the mind across time can help us become more responsible planetary stewards and foster empathy across generations.

Posted on Aug 10, 2021

Source: Jake Weirick, via Unsplash

By: Vincent Ialenti

The word has been out for decades: We were born on a damaged planet careening toward environmental collapse. Yet our intellects are poorly equipped to grasp the scale of the Earth’s ecological death spiral. We strain to picture how, in just a few decades, climate change may displace entire populations. We struggle to envision the fate of plastic waste that will outlast us by centuries. We fail to imagine our descendants inhabiting an exhausted Earth worn out from resource extraction and devoid of biodiversity. We lack frames of reference in our everyday lives for thinking about nuclear waste’s multimillennial timescales of radioactive hazard.

I am an anthropologist who studies how societies hash out relationships between living communities of the present and unborn communities imagined to inhabit the future. Studying how a community relates to the passage of time, I’ve learned, can offer a window into its values, worldviews, and lifeways.

This article adapted from Vincent Ialenti’s book “Deep Time Reckoning: How Future Thinking Can Help Earth Now.”

From 2012 to 2014, I conducted 32 months of anthropological fieldwork exploring how Finland’s nuclear energy waste experts grappled with Earth’s radically long-term future. These experts routinely dealt with long-lived radionuclides such as uranium-235, which has a half-life of over 700 million years. They worked with the nuclear waste management company Posiva to help build a final disposal facility approximately 450 meters below the islet of Olkiluoto in the Gulf of Bothnia in the Baltic Sea. If all goes according to plan, this facility will, in the mid-2020s, become the world’s first operating deep geologic repository for spent nuclear fuel.

To assess the Olkiluoto repository’s long-term durability, these experts developed a “safety case” forecasting geological, hydrological, and ecological events that could potentially occur in Western Finland over the coming tens of thousands — or even hundreds of thousands — of years. From their efforts emerged visions of distant future glaciations, climate changes, earthquakes, floods, human and animal population changes, and more. These forecasts became the starting point for a series of “mental time travel” exercises that I incorporated into my book, “Deep Time Reckoning.”

Stretching the mind across time — even in the most speculative ways — can help us become more responsible planetary stewards: It can help endow us with the time literacy necessary for tackling long-term challenges such as biodiversity loss, microplastics accumulation, climate change, antibiotic resistance, asteroid impacts, sustainable urban planning, and more. This can not only make us feel more at home in pondering our planet’s pasts and futures. It can also draw us to imagine the world from the perspective of future human and non-human communities — fostering empathy across generations.

5710 CE. A tired man lounges on a sofa. He lives in a small wooden house in a region once called Eurajoki, Finland. He works at a local medical center. Today is his day off. He’s had a long day in the forest. He hunted moose and deer and picked lingonberries, mushrooms, and bilberries. He now sips water, drawn from a village well, from a wooden cup. His husband brings him a dinner plate. On it are fried potatoes, cereal, boiled peas, and beef. All the food came from local farms. The cattle were watered at a nearby river. The crops were watered by irrigation channels flowing from three local lakes.

The man has no idea that, more than 3,700 years ago, safety case biosphere modelers used 21st-century computer technologies to reckon everyday situations like his. He does not know that they once named the lakes around him — which formed long after their own deaths — “Liiklanjärvi,” “Tankarienjärvi,” and “Mäntykarinjärvi.” He is unaware of Posiva’s ancient determination that technological innovation and cultural habits are nearly impossible to predict even decades in advance. He is unaware that Posiva, in response, instructed its modelers to pragmatically assume that Western Finland’s populations’ lifestyles, demographic patterns, and nutritional needs will not change much over the next 10,000 years. He does not know the safety case experts inserted, into their models’ own parameters, the assumption that he and his neighbors would eat only local food.

Yet the hunter’s life is still entangled with the safety case experts’ work. If they had been successful, then the vegetables, meat, fruit, and water before him should have just a tiny chance of containing only tiny traces of radionuclides from 20th-century nuclear power plants.

12020 CE. A solitary farmer looks out over her pasture, surrounded by a green forest of heath trees. She lives in a sparse land once called Finland, on a fertile island plot once called Olkiluoto. The area is an island no longer. What was once a coastal bay is now dotted with small lakes, peat bogs, and mires with white sphagnum mosses and grassy sedge plants. The Eurajoki and Lapijoki Rivers drain out into the sea. When the farmer goes fishing at the lake nearby, she catches pike. She watches a beaver swim about. Sometimes she feels somber. She recalls the freshwater ringed seals that once shared her country before their extinction.

The woman has no idea that, deep beneath her feet, lies an ancestral deposit of copper, iron, clay, and radioactive debris. This is a highly classified secret — leaked to the public several times over the millennia, but now forgotten. Yet even the government’s knowledge of the burial site is poor. Most records were destroyed in a global war in the year 3112. It was then that ancient forecasts of the site, found in the 2012 safety case report “Complementary Considerations,” were lost to history.

But the farmer does know the mythical stories of Lohikäärme: a dangerous, flying, salmon-colored venomous snake that kills anyone who dares dig too close to his underground cave. She and the other farmers in the area grow crops of peas, sugar beet, and wheat. They balk at the superstitious fools who tell them the monster living beneath their feet is real.

35,012 CE. A tiny microbe floats in a large, northern lake. It does not know that the clay, silt, and mud floor below it is gaining elevation, little by little, year after year. It is unaware that, 30 millennia ago, the lake was a vast sea. Dotted with sailboats, cruise and cargo ships, it was known by humans as the Baltic. Watery straits, which connected the Baltic Sea to the North Sea, had risen above the water thousands of years ago. Denmark and Sweden fused into a single landmass. The seafloor was decompressing from the Weichselian glaciation — an enormous sheet of ice that pressed down on the land during a previous ice age.

After the last human died, the landmass kept on rising. Its uplift was indifferent to human extinction. It was indifferent to how, in 2013 CE, an anthropologist and a safety case expert sat chatting in white chairs in Ravintola Rytmi: a café in Helsinki. There, the safety case expert relayed his projection that, by 52,000 CE, there would no longer be water separating Turku, Finland, and Stockholm, Sweden. At that point, one could walk from one city to the other on foot. The expert reckoned that, to the north — between Vaasa, Finland, and Umeå, Sweden — one would someday find a waterfall with the planet’s largest deluge of flowing water. The waterfall could be found at the site of a once-submerged sea shelf.

The microbe, though, does not know or care about Vaasa, Umeå, Denmark, long-lost boats, safety case reports, or Helsinki’s past dining options. It has no concept of them. Their significances died with the humans. Nor does the microbe grasp the suffering they faced when succumbing to Anthropocene collapse. Humans’ past technological feats, grand civilizations, passion projects, intellectual triumphs, wartime sacrifices, and personal struggles are now moot. And yet, the radiological safety of the microbe’s lake’s waters still hinges on the work of a handful of human safety case experts who lived millennia ago. Thinking so far ahead, these experts never lived to see whether their deep time forecasts were accurate.

We do not, of course, live in these imagined worlds. In this sense, they are unreal — merely fictions. However, our capacities to envision potential futures, and to feel empathy for those who may inhabit them, are very real. Depictions of tomorrow can have powerful, concrete effects on the world today. This is why deep time thought experiments are not playful games, but serious acts of intellectual problem-solving. It is why the safety case experts’ models of far future nuclear waste risks are uniquely valuable, even if they are, at the end of the day, mere approximations.

Yet pondering distant future Earths can also help us take a step back from our everyday lives — enriching our imaginations by transporting our minds to different places and times. Corporate coaches have recommended taking breaks from our familiar thinking patterns to experience the world in new ways and overcome mental blocks. Cognitive scientists have shown how creativity can be sparked by perceiving “something one has not seen before (but that was probably always there).”

Putting aside a few minutes each day for long-termist, planetary imagination can enrich us with greater mental dexterity in navigating between multiple, interacting timescales. This can cultivate more longsighted empathy for landscapes, people, and other organisms across decades, centuries, and millennia. As the global ecological crisis takes hold, embracing planetary empathy will prove essential to our collective survival.

—

Vincent Ialenti is a Research Fellow at The University of Southern California and The Berggruen Institute. His recent book, “Deep Time Reckoning,” is an anthropological study of how Finland’s nuclear waste repository experts grappled with distant future ecosystems and the limits of human knowledge.

Usina Nuclear de Angra 3 e a Operação Lava Jato (JC)

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Para o físico Heitor Scalambrini Costa, denúncias de propinas na construção da usina e objeções técnicas quanto à obsolescência dos equipamentos tecnologicamente defasados, são fatos graves que devem ser apurados com urgência

Apesar de toda a movimentação no cenário internacional acerca dos problemas e riscos de instalações nucleares, que ficou exacerbada após o desastre de Fukushima (11/3/2011), surpreende a posição das autoridades do Ministério de Minas e Energia, dos “lobistas” da área nuclear,das empreiteiras e fornecedoras de equipamentos ― pois todos continuam insistindo na instalação de mais quatro usinas nucleares no país até 2030, sendo duas delas no Nordeste brasileiro. Além da construção de Angra 3 ― já aprovada.

No caso de Angra 3, a estimativa de custos da obra era de R$ 7,2 bilhões, em 2008; pulou para R$ 10,4 bilhões,no final de 2010;em julho de 2013, de acordo com a Eletronuclear, superava os R$ 13 bilhões; e, até 2018, ano de sua conclusão, devem alcançar R$ 14,9 bilhões. Obviamente a duplicação nos custos de construção desta usina nuclear impactam decisivamente o preço médio de venda de eletricidade no país.

A história da indústria nuclear no Brasil mostra que ela sempre foi ― e continua sendo ― uma indústria altamente dependente de subsídios públicos. Sem dúvida, são perversas as condições de financiamento de Angra 3, com subsídios governamentais ocultos, a serem posteriormente disfarçados nas contas de luz. E quem vai pagar essa conta seremos nós, os usuários, que já pagamos uma das mais altas tarifas de energia elétrica do mundo.

Com a Operação Lava Jato, deflagrada em março de 2014, para investigar um grande esquema de lavagem e desvio de dinheiro envolvendo a Petrobras, grandes empreiteiras do país e diversos políticos, começam a ter desnudados os reais interesses, nada republicanos, da decisão de construção das grandes obras energéticas, como a usina hidroelétrica de Belo Monte e a usina nuclear Angra 3.

Desde a decisão de construí-la no âmbito do conturbado acordo nuclear Brasil-Alemanha, a usina de Angra 3foi cercada de mistério, controvérsias, incertezas e falta de transparência, comuns no setor nuclear brasileiro.

As obras civis da usina foram licitadas à Construtora Andrade Gutierrez mediante contrato assinado em 16 de junho de 1983(governo Figueiredo, 1979-1985). Em abril de 1986, as obras foram paralisadas por falta de recursos, alto custo e dúvidas quanto à conveniência e riscos desta fonte de energia. Mesmo assim a construtora recebeu durante décadas um pagamento de aproximadamente US$ 20 milhões/ano.

Depois de 23 anos parada, as obras de Angra 3 foram retomadas em 2009 (governo Lula, 2003-2010). O governo Lula optou por não fazer licitações, e revalidou a concorrência ganha pela construtora Andrade Gutierrez, em 1983. Embora não tenha feito novas licitações, a Eletronuclear negociou atualizações de valores com todos os fornecedores e prestadores de serviços. A obra e seus equipamentos ficaram bem mais caros. Em dólares, seu valor pulou de US$ 1,8 bilhão para aproximadamente cerca de US$ 3,3 bilhões.

Diante da decisão de manter o contrato com a Andrade Gutierrez, construtoras concorrentes, especialmente a Camargo Corrêa, tentaram em vão convencer o governo a rever sua decisão, alegando que neste período houve uma revolução tecnológica que reduziu em até 40% o custo de obras civis de usinas nucleares. Também o plenário do Tribunal de Contas da União, em setembro de 2008, ao avaliar o assunto não impediu a revalidação dos contratos. Porém considerou que Angra 3 apresentava “indícios de irregularidade grave” sem recomendar, todavia, a paralisação do empreendimento.

O contrato das obras civis não foi o único a ser tirado do congelador pelo governo Lula. Para o fornecimento de bens e serviços importados foi definida a fabricante Areva, empresa resultante da fusão entre a alemã Siemens KWU e a francesa Framatome. A rigor, a Areva nem assinou o contrato. Ela foi escolhida porque herdou da KWU o acordo original.

Já os contratos da montagem foram assinados em 2 de setembro de 2014 com os seguintes consórcios: consórcio ANGRA 3, para a realização dos serviços de montagens eletromecânicas dos sistemas associados ao circuito primário da usina (sistemas associados ao circuito de geração de vapor por fonte nuclear),constituído pela empresas Construtora Queiroz Galvão S.A., EBE – Empresa Brasileira de Engenharia S.A. e Techint Engenharia S.A. E consórcio UNA 3, para a execução das montagens associadas aos sistemas convencionais da usina, constituído pelas empresas Construtora Andrade Gutierrez S.A., Construtora Norberto Odebrecht S.A., Construções e Comércio Camargo Corrêa S.A. e UTC Engenharia S.A.

O atual planejamento da Eletronuclear prevê a entrada em operação de Angra 3 em maio de 2018. Mas esta meta deverá ser revista depois de a obra ser praticamente paralisada no final de abril de 2014, devido à alegação de dívidas não pagas a empreiteira (governo Dilma, 2011-2014).

Depois de todos estes percalços, para uma obra tão polêmica, tomamos conhecimento das denúncias feitas por um dos executivos da empreiteira Camargo Correa, que passou a colaborar com as investigações da Operação Lava Jato e relatou aos procuradores, durante negociações para o acordo de delação premiada, uma suposta propina para o ex-ministro das Minas e Energia, Edson Lobão, na contratação da Camargo Correa para a execução de obras da usina de Angra 3.

Caso se confirmem tais acusações ficará claro para a sociedade brasileira que os reais interesses pela construção de Angra 3 e de mais 4 usinas nucleares tiveram como principal motivação as altas somas que autoridades públicas receberam como suborno. É bom lembrar que neste caso o ministro Lobão tinha poder de comando sobre a empresa pública responsável pela obra, a Eletronuclear ― subsidiária da Eletrobrás.

A partir deste episódio não podemos mais ignorar as objeções técnicas, como as denúncias com relação à obsolescência dos equipamentos tecnologicamente defasados (comprometendo o seu funcionamento e aumentando o risco de um desastre nuclear). Nem as denúncias de que o custo desta obra poderia encarecer durante a sua construção ― o que,de fato, já aconteceu.Tampouco o questionamento sobre o empréstimo realizado pela Caixa Econômica Federal, para a construção de Angra 3.

A expectativa é que todas as denúncias sejam investigadas e apuradas as responsabilidades. O fato em si é gravíssimo, e suficiente para a interrupção das atividades nucleares no país, em particular a construção de Angra 3, com o congelamento de novas instalações. Não se pode admitir que a decisão de construir centrais nucleares no país tenha sido feita em um mero balcão de negócios.

Heitor Scalambrini Costa é graduado em Física pela Universidade de Campinas/SP, mestrado em Ciências e Tecnologias Nucleares na Universidade Federal de Pernambuco, e doutorado em Energética – Université dAix-Marseille III (Droit, Econ. et Sciences (1992). Atualmente é professor associado da Universidade Federal de Pernambuco.

Doomsday Clock Set at 3 Minutes to Midnight (Live Science)

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by Megan Gannon, News Editor   |   January 22, 2015 01:25pm ET

Mushroom cloud over Nagasaki
A gigantic mushroom cloud billowed over Nagasaki, Japan, when an atomic bomb was dropped on the city in 1945.

Credit: U.S. National Archives

The world is “3 minutes” from doomsday.

That’s the grim outlook from board members of The Bulletin of the Atomic Scientists. Frustrated with a lack of international action to address climate change and shrink nuclear arsenals, they decided today (Jan. 22) to push the minute hand of their iconic “Doomsday Clock” to 11:57 p.m.

It’s the first time the clock hands have moved in three years; since 2012, the clock had been fixed at 5 minutes to symbolic doom, midnight. [End of the World? Top Doomsday Fears]

The Bulletin of the Atomic Scientists doesn’t use the clock to make any real doomsday predictions. Rather, the clock is a visual metaphor to warn the public about how close the world is to a potentially civilization-ending catastrophe. Each year, the magazine’s board analyzes threats to humanity’s survival to decide where the Doomsday Clock’s hands should be set.

Experts on the board said they felt a sense of urgency this year because of the world’s ongoing addiction to fossil fuels, procrastination with enacting laws to cut greenhouse gas emissions and slow efforts to get rid of nuclear weapons.

“We are not saying it is too late to take action but the window for action is closing rapidly,” Kennette Benedict, executive director of The Bulletin of the Atomic Scientists, said in a news conference this morning in Washington, D.C. “We move the clock hand today to inspire action.”

For instance, if nothing is done to reduce the amount of heat-trapping gasses, such as carbon dioxide, in the atmosphere, Earth could be 5 to 15 degrees Fahrenheit (3 to 8 degrees Celsius) warmer by the end of century, said Sivan Kartha, a senior scientist at the Stockholm Environment Institute.

Some people might not feel alarmed when they see those numbers; they might normally experience that kind of temperature swing in the course of a single day, Kartha said. But, he said a temperature increase of that magnitude was enough to bring the world out of the last ice age, and it will be enough to “radically transform” the Earth’s surface in the future.

Sharon Squassoni, another board member and director of the Proliferation Prevention Program at the Center for Strategic and International Studies, said nuclear disarmament efforts have “ground to a halt” and many nations are expanding, not scaling back, their nuclear capabilities. Russia is upgrading its nuclear program, India plans to expand its nuclear submarine fleet, and Pakistan has reportedly started operating a third plutonium reactor, Squassoni said.

She said the United States has good rhetoric on nuclear nonproliferation, but at the same time is in the midst of a $335 billion overhaul of its nuclear program. (That figure seems to come from a Congressional Budget Office report from December 2013.)

“The risk from nuclear weapons is not that someone is going to press the button, but the existence of these weapons costs a lot of time, effort and money to keep them secure,” Squassoni said, adding that there have been troubling safety discrepancies reported in recent years at power plants.

The Bulletin of the Atomic Scientists was founded in 1945 by scientists who created the atomic bomb as part of the Manhattan Project and wanted to raise awareness about the dangers of nuclear technology. The Doomsday Clock first appeared on a cover of the magazine in 1947, with its hands set at 11:53 p.m.

The clock’s hands shifted quite a bit over the following seven decades. They were closest to midnight in 1953, set at 11:58 p.m., after both the United States and the Soviet Union conducted their first tests of the hydrogen bomb. The clock’s hands were pushed all the way back to 11:43 p.m., 17 minutes to midnight, in December 1991, after the world’s superpowers signed the Strategic Arms Reduction Treaty, which at the time, seemed like a promising move toward nuclear disarmament.

Falta de chuva reforça necessidade de usinas nucleares, dizem especialistas (Agência Brasil)

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Especialistas participaram do 3º Seminário sobre Energia Nuclear, na Universidade Estadual do Rio de Janeiro (UERJ)

A falta de chuva em diversas regiões do país, principalmente no Sudeste, aponta para a necessidade de se prosseguir com os investimentos em usinas nucleares. A seca, além de afetar o fornecimento de água para a população, também compromete a geração de energia das usinas hidrelétricas, aumentando a importância das nucleares. A avaliação é de especialistas que participaram do 3º Seminário sobre Energia Nuclear, na Universidade Estadual do Rio de Janeiro (UERJ), iniciado ontem, 7, e que se encerra nesta quarta-feira, 8.

O presidente das Indústrias Nucleares do Brasil (INB), Aquilino Senra, frisou que a matriz energética brasileira é muito baseada na hidreletricidade, que vem sendo afetada pelas reiteradas e prolongadas secas nos últimos anos.

“No Brasil, a produção hídrica contribui com 92% de toda energia gerada. Os 8% restantes vêm de uma complementação térmica, na qual a nuclear tem um papel de 4%. Essa situação de baixos reservatórios levará a uma tomada de decisão mais rápida sobre a expansão da produção de energia nuclear. É inevitável, nas próximas décadas, um potencial de crescimento nuclear”, disse Senra.

O supervisor da Gerência de Análise de Segurança Nuclear da Eletronuclear, Edson Kuramoto, disse que a menor quantidade de chuva nos últimos anos forçou o governo a utilizar totalmente as usinas térmicas, incluindo as nucleares, para garantir o fornecimento. “Hoje está demonstrado que a matriz energética brasileiras é hidrotérmica.

Desde 2012, com a redução das chuvas, os reservatórios estão baixos e as térmicas foram despachadas justamente para complementar a falta da geração hidráulica. A energia nuclear tem que ser lembrada, porque o Brasil domina o ciclo e nós temos grandes reservas do combustível”, disse Kuramoto.

Segundo Kuramoto, além das usinas Angra 1 e 2, já em funcionamento, e Angra 3, em construção, o país precisará de pelo menos mais quatro usinas nucleares, sendo duas no Nordeste e duas no Sudeste. “O potencial de hidrelétricas que temos ainda é no Norte do país, mas está difícil o licenciamento de novas usinas com reservatórios. No passado, nossas hidrelétricas suportavam um recesso de chuvas de seis ou sete meses, hoje é três meses. Então o país vai ter que investir nas usinas térmicas. Até 2030, finda o nosso potencial hidráulico. A partir daí, o Brasil terá de construir novas térmicas, sejam nucleares, a gás, óleo combustível ou carvão.”

Segundo o presidente da INB, o Brasil tem garantidas reservas de urânio pelos próximos 120 anos pelo menos. Isso garante um custo baixo do combustível, que ainda tem a vantagem de não emitir gases de efeito estufa. Para Senra, a questão da segurança, muito questionada por causa do acidente da Usina de Fukushima, no Japão, já está solucionada com as novas gerações de usinas.

“Os reatores de Fukushima são de segunda geração. Os que estão começando a ser instalados agora são de terceira geração e neles não ocorreriam acidentes como os que já ocorreram, seja em 1979, nos Estados Unidos [em Three Mile Island, Pensilvânia], ou em 1986, em Chernobil [Ucrânia], e em 2011, em Fukishima”, explicou Senra.

(Vladimir Platonow/Agência Brasil)

http://agenciabrasil.ebc.com.br/geral/noticia/2014-10/falta-de-chuva-reforca-necessidade-de-usinas-nucleares-dizem-especialistas

Brazil builds nuclear submarine to patrol offshore oil (Channel News Asia)

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POSTED: 04 Jun 2014 07:15

Brazil is building five submarines to patrol its massive coast, including one powered by an atomic reactor that would put it in the small club of countries with a nuclear sub.

The BNS S34 Tikuna Brazilian diesel-electric powered submarine moored at the navy base in Niteroi, Brazil. (AFP/Yasuyoshi Chiba)

RIO DE JANEIRO: Brazil is building five submarines to patrol its massive coast, including one powered by an atomic reactor that would put it in the small club of countries with a nuclear sub.

The South American giant is in the process of exploring major oil fields off its shores that could make it one of the world’s top petroleum exporters.

The new submarines aim to protect that resource, said the navy official coordinating the US$10-billion project, Gilberto Max Roffe Hirshfeld.

“The nuclear-propelled submarine is one of the weapons with the greatest power of dissuasion,” he told AFP.

“Brazil has riches in its waters. It’s our responsibility to have strong armed forces. Not to make war, but to avoid war. So that no one tries to take away our riches.”

The new submarines, which will replace Brazil’s aging fleet of five conventional subs, are being built at a sprawling 540,000-square-metre complex in Itaguai, just south of Rio de Janeiro.

The project is a joint venture between the navy, Brazilian construction firm Odebrecht and French state defense firm DCNS.

Brazil and France signed a deal for the project in 2008 under which DCNS is providing building materials and training while Brazil builds up its own submarine industry.

Brazil is developing the nuclear reactor and enriched uranium itself.

The first submarine, a conventional sub called SBR1, is 45-percent complete and scheduled to launch in 2017. The second is in the early stages of construction and is due to launch in 2019.

Work on the nuclear sub, SNBR, is supposed to start in 2017, with a launch target of 2025, the year the project wraps up.

Workers are assembling the submarines in a massive 38-metre-tall hangar, putting together the giant sheets of steel that will form the hulls.

When complete, the nuclear submarine will measure 100 metres long and weigh 6,000 tonnes. Its conventional cousins will be slightly smaller, at 75 metres and 2,000 tonnes.

Currently the only countries to design and build their own nuclear submarines are the permanent members of the United Nations Security Council — Britain, China, France, Russia and the United States — plus India, which has completed one and is in the process of building more.

Unlike conventional submarines, which run on electric or diesel engines and have to resurface every 12 to 24 hours to refuel, nuclear submarines run on atomic power and can stay immersed indefinitely.

They can also be outfitted to launch nuclear warheads — though under Brazil’s constitution and the Nuclear Non-Proliferation Treaty, the country is barred from developing atomic weapons.

Its five new submarines will be equipped with conventional torpedos.

Brazil’s navy says the conventional submarines will patrol ports and other strategic points along the country’s 8,500-kilometre coast.

The SNBR will patrol farther away, around the country’s “pre-salt” deepwater oil reserves — estimated at up to 35 billion barrels — and the so-called Blue Amazon, a biodiverse area off the coast with minerals including gold, manganese and limestone.

According to the Stockholm International Peace Research Institute, Brazil had one of the world’s 15 largest defense budgets in 2013, at US$31.5 billion.

– AFP/de

Indígenas dos Estados Unidos exigem limpeza do pior lixão nuclear do Projeto Manhattan (IPS)

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24/4/2014 – 01h33

por Michelle Tolson, da IPS

cartel Indígenas dos Estados Unidos exigem limpeza do pior lixão nuclear do Projeto Manhattan

Nação Yakama, Estados Unidos, 24/4/2014 – Executivos, políticos e funcionários do Departamento de Energia dos Estados Unidos discutiam como alertar as gerações que viverão dentro de 125 mil anos sobre o lixo radioativo de Hanford, o local mais contaminado do país, localizado no extremo noroeste. “Eu lhes direi como”, interrompeu o nativo Russell Jim.

“Olharam entre si e depois para mim. Então lhes disse: estamos aqui desde o começo dos tempos, por isso também estaremos nessa oportunidade. Aí se deram conta de que tinham um problema nas mãos”, conta à IPS este homem de 78 anos que faz parte do povo yakama. Com suas longas tranças, Jim é uma figura impactante. Dirige o Programa de Recuperação Ambiental e Manejo de Resíduos (ERWM) das tribos yakama e permanece tranquilamente sentado em seu escritório nas áridas terras da Nação Yakama.

A reserva, situada no sudeste do Estado de Washington, tem 486 mil hectares, dez mil integrantes de tribos reconhecidas federalmente e cerca de 12 mil cavalos selvagens vagando pelas desertas estepes. É o que resta de um território de quase cinco milhões de hectares que, em 1855, os yakamas tiveram que ceder pela força ao governo norte-americano, e está a apenas 32 quilômetros do complexo nuclear de Hanford.

Embora a corrida armamentista nuclear tenha terminado em 1989, o lixo radioativo é a herança deixada em diferentes lugares deste país pelo Projeto Manhattan. Hanford, em particular, começou a operar em 1943. Aqui foi produzido o plutônio da bomba atômica que os Estados Unidos lançaram sobre a cidade japonesa de Nagasaki, em 1945. Chegou a ter nove reatores e cinco grandes complexos para processar esse metal pesado. Hoje está quase totalmente desmantelado. Mas segue contendo e vazando radioatividade muito prejudicial.

Os yakamas conseguiram evitar que seus pesqueiros ancestrais se convertessem em depósitos de resíduos procedentes de outros lugares, invocando o tratado de 1855 que lhes assegura acesso aos seus “lugares usuais e costumeiros”. Mas Hanford está longe de ser um ambiente são, apesar da promessa de limpeza feita pelo Departamento de Energia. “O governo está tentando reclassificar o lixo como de ‘baixa radioatividade’. Querem deixá-lo aqui e enterrá-lo em lixões quase superficiais. Mas os cientistas dizem que é preciso enterrar a grande profundidade”, afirmou Jim.

Tom Carpenter, da organização Hanford Challenge, explicou à IPS que esta “é uma batalha para que os federais cumpram sua promessa de retirar o lixo pelo Estado de Washington e pelas tribos. Há 67,5 quilômetros de faixas cavadas de 4,5 metros de largura por seis metros de profundidade, sem revestimento e cheias de caixas e frascos de resíduos”. Além disso, há 177 tanques subterrâneos de lixo radioativo e seis deles apresentam vazamentos. Supõe-se que quando se detecta um vazamento os resíduos devem ser retirados no prazo de 24 horas ou quando for “praticável”. Mas as empresas contratadas dizem que não há espaço suficiente.

Três denunciantes que trabalhavam nas tarefas de limpeza expressaram suas preocupações e foram demitidos. A denúncia foi divulgada por uma emissora local, mas os grandes meios de comunicação a ignoram, como fazem com a luta dos yakamas. “Antes tínhamos um encarregado de imprensa, mas o Departamento de Energia disse que não precisávamos dele porque está tudo bem”, contou Jim. O ERWM é financiado por esse Departamento, mas perdeu 80% dos fundos após um corte federal.

Naturalmente, não está tudo bem. Os sedimentos radioativos chegaram às camadas subterrâneas e dali ao rio Colúmbia. Alguns vazamentos estão a pouco mais de cem metros do curso de água, onde as tribos têm acesso ao monumento nacional Hanford Reach. Esta reserva natural, uma área de amortização do complexo nuclear, é a maior área de desova do salmão real no rio Colúmbia.

O governo do Estado de Washington informa que a água subterrânea contaminada com urânio, estrôncio 90 e cromo já entrou no curso do rio. “No leito do rio há cerca de 150 fluxos de água subterrânea de Hanford entre as quais nadam os salmões jovens”, pontuou Jim. “Helen Caldicott (fundadora da organização Médicos Pela Responsabilidade Social) nos disse, em 1997, que se comêssemos pescado do Colúmbia morreríamos”, acrescentou.

lider Indígenas dos Estados Unidos exigem limpeza do pior lixão nuclear do Projeto ManhattanA consultora ambiental dos yakamas, Callei Ridolfi, afirmou à IPS que a dieta desses indígenas contém entre 150 e 519 gramas de pescado por dia, quase o dobro do ingerido por outras tribos e muito mais do que a população geral. Por isso têm possibilidade de um em 50 contrair câncer pela ingestão de pescado de espécies não migratórias. Já o salmão, que passa a maior parte de sua vida no oceano, é menos afetado. Segundo um estudo publicado em 2002 pela Agência de Proteção Ambiental sobre os contaminantes que afetam os peixes da região, o esturjão e o coregono-de-montanha eram os que apresentavam maiores concentrações de bifenil policlorado (PCB).

No ano passado, os Estados de Washington e Oregon recomendaram limitar a uma vez na semana o consumo de peixes residentes em uma faixa do Colúmbia onde há várias represas, devido à contaminação com PCB. “Os lubrificantes com PCB foram usados durante anos nos transformadores, sobretudo em represas hidrelétricas”, disse à IPS o administrador de pesca da Comissão Intertribal de Pesca do Rio Colúmbia, Mike Matylewich.

Embora a recomendação não incluísse Hanford Reach, onde não há represas, Jim duvida de sua segurança. “O Departamento de Energia disse ao Congresso que o corredor do rio está limpo. Não está, mas eles temem ser processados”, afirmou este homem que sobreviveu a um câncer. Sua tribo nunca foi indenizada pelos vazamentos radioativos ocorridos entre 1944 e 1971 e que chegaram a 6,3 milhões de curies de netúnio-239. O toxicologista Steven G. Gilbert, da Médicos Pela Responsabilidade Social, assegura que falta transparência e informação sobre a limpeza de Hanford, que é um “enorme problema”.

Dos nove reatores nucleares, oito foram desativados. Mas a geradora elétrica da Energy Northwest, de 1.175 megawatts, ainda funciona. “Muita gente não sabe que há um reator nuclear que continua funcionando. E é do mesmo tipo que o de Fukushima, no Japão”, pontuou Gilbert.

Em meio a esta disputa estão as tribos, que são nações soberanas. Russell Jim afirma que frequentemente se comete o erro de descrevê-las como “partes interessadas”, quando são governos separados. “Fomos a única tribo a denunciar a questão nuclear e testemunhar em um subcomitê do Senado em 1980. Em 1982, solicitamos o statusde tribo afetada. Os umatillas e os nez percés nos seguiram mais tarde”, observou.

A cadeia montanhosa Yucca Mountain, no Estado de Nevada, foi designada pelo Congresso como lugar de armazenamento provisório dos resíduos de Hanford e outros complexos nucleares, mas o presidente Barack Obama eliminou o plano. Duas tribos dessa região, os paiutes do sul e os shoshones ocidentais, também se declararam afetadas. A Planta-Piloto de Isolamento de Resíduos (WIPP) do Estado do Novo México, foi então destinada a receber o lixo de Hanford, mas depois de um incêndio em fevereiro isso já não é mais possível.

O Boletim de Cientistas Atômicos expressou, no dia 23 de março, sua preocupação porque não há lugares onde armazenar esses perigosos dejetos. Os Estados Unidos têm as maiores existências do mundo de combustível nuclear usado, cinco vezes mais do que a Rússia. “O melhor material para armazená-lo é o granito, abundante no nordeste. Um local ideal fica a 48 quilômetros da capital, mas isso está fora de consideração” por sua proximidade com a Casa Branca, apontou Jim, com um sorriso mordaz. Mas esse veterano líder nativo não pensa em se render. “Nós somos os únicos que não podemos sair daqui”, enfatizou. Envolverde/IPS

(IPS)

How does radioactive waste interact with soil and sediments? (Science Daily)

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Date: February 3, 2014

Source: Sandia National Laboratories

Summary: Scientists are developing computer models that show how radioactive waste interacts with soil and sediments, shedding light on waste disposal and how to keep contamination away from drinking water.

Sandia National Laboratories geoscientist Randall Cygan uses computers to build models showing how contaminants interact with clay minerals. Credit: Lloyd Wilson

Sandia National Laboratories is developing computer models that show how radioactive waste interacts with soil and sediments, shedding light on waste disposal and how to keep contamination away from drinking water.

“Very little is known about the fundamental chemistry and whether contaminants will stay in soil or rock or be pulled off those materials and get into the water that flows to communities,” said Sandia geoscientist Randall Cygan.

Researchers have studied the geochemistry of contaminants such as radioactive materials and toxic heavy metals, including lead, arsenic and cadmium. But laboratory testing of soils is difficult. “The tricky thing about soils is that the constituent minerals are hard to characterize by traditional methods,” Cygan said. “In microscopy there are limits on how much information can be extracted.”

He said soils are often dominated by clay minerals with ultra-fine grains less than 2 microns in diameter. “That’s pretty small,” he said. “We can’t slap these materials on a microscope or conventional spectrometer and see if contaminants are incorporated into them.”

Cygan and his colleagues turned to computers. “On a computer we can build conceptual models,” he said. “Such molecular models provide a valuable way of testing viable mechanisms for how contaminants interact with the mineral surface.”

He describes clay minerals as the original nanomaterial, the final product of the weathering process of deep-seated rocks. “Rocks weather chemically and physically into clay minerals,” he said. “They have a large surface area that can potentially adsorb many different types of contaminants.”

Clay minerals are made up of aluminosilicate layers held together by electrostatic forces. Water and ions can seep between the layers, causing them to swell, pull apart and adsorb contaminants. “That’s an efficient way to sequester radionuclides or heavy metals from ground waters,” Cygan said. “It’s very difficult to analyze what’s going on in the interlayers at the molecular level through traditional experimental methods.”

Molecular modeling describes the characteristics and interaction of the contaminants in and on the clay minerals. Sandia researchers are developing the simulation tools and the critical energy force field needed to make the tools as accurate and predictive as possible. “We’ve developed a foundational understanding of how the clay minerals interact with contaminants and their atomic components,” Cygan said. “That allows us to predict how much of a contaminant can be incorporated into the interlayer and onto external surfaces, and how strongly it binds to the clay.”

The computer models quantify how well a waste repository might perform. “It allows us to develop performance assessment tools the Environmental Protection Agency and Nuclear Regulatory Commission need to technically and officially say, ‘Yes, let’s go ahead and put nuclear waste in these repositories,'” Cygan said.

Molecular modeling methods also are used by industry and government to determine the best types of waste treatment and mitigation. “We’re providing the fundamental science to improve performance assessment models to be as accurate as possible in understanding the surface chemistry of natural materials,” Cygan said. “This work helps provide quantification of how strongly or weakly uranium, for example, may adsorb to a clay surface, and whether one type of clay over another may provide a better barrier to radionuclide transport from a waste repository. Our molecular models provide a direct way of making this assessment to better guide the design and engineering of the waste site. How cool is that?”

GENERAL OVERVIEW OF THE EFFECTS OF NUCLEAR TESTING (CTBTO)

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The material contained in this chapter is based on official government sources as well as information provided by research institutions, policy organizations, peer-reviewed journals and eye witness accounts. 

http://www.ctbto.org/nuclear-testing/the-effects-of-nuclear-testing/

The CTBTO remains neutral in any ongoing disputes related to compensation for veterans of the nuclear test programmes.  

Nuclear weapons have been tested in all environments since 1945: in the atmosphere, underground and underwater. Tests have been carried out onboard barges, on top of towers, suspended from balloons, on the Earth’s surface, more than 600 metres underwater and over 200 metres underground. Nuclear test bombs have also been dropped by aircraft and fired by rockets up to 320 km into the atmosphere.

The National Resources Defense Council estimated the total yield of all nuclear tests conducted between 1945 and 1980 at 510 megatons (Mt). Atmospheric tests alone accounted for 428 mt, equivalent to over 29,000 Hiroshima size bombs.

Frigate Bird nuclear test explosion seen through the periscope of the submarine USS Carbonero (SS-337), Johnston Atoll, Central Pacific Ocean, 1962.

The first nuclear test was carried out by the United States in July 1945, followed by the Soviet Union in 1949, the United Kingdom in 1952, France in 1960, and China in 1964. The National Resources Defense Council estimated the total yield of all nuclear tests conducted between 1945 and 1980 at 510 megatons (Mt). Atmospheric tests alone accounted for 428 mt, equivalent to over 29,000 Hiroshima size bombs.

The amount of radioactivity generated by a nuclear explosion can vary considerably depending upon a number of factors. These include the size of the weapon and the location of the burst. An explosion at ground level may be expected to generate more dust and other radioactive particulate matters than an air burst. The dispersion of radioactive material is also dependent upon weather conditions.

Large amounts of radionuclides dispersed into the atmosphere

Levels of radiocarbon (C14) in the atmosphere 1945 – 2000. Image credit: Hokanomono.

The 2000 Report of the United Nations Scientific Committee on the Effects of Atomic Radiation to the General Assemblystates that:
“The main man-made contribution to the exposure of the world’s population [to radiation] has come from the testing of nuclear weapons in the atmosphere, from 1945 to 1980. Each nuclear test resulted in unrestrained release into the environment of substantial quantities of radioactive materials, which were widely dispersed in  the atmosphere and deposited everywhere on the Earth’s surface.”

The first nuclear test was carried out by the United States in July 1945, followed by the Soviet Union in 1949, the United Kingdom in 1952, France in 1960, and China in 1964.

Different types of nuclear tests: (1) atmospheric test; (2) underground test; (3) upper atmospheric test; and (4) underwater test.

Concern over bone-seeking radionuclides and the first mitigating steps

Prior to 1950, only limited consideration was given to the health impacts of worldwide dispersion of radioactivity from nuclear testing. Public protests in the 1950s and concerns about the radionuclide strontium-90 (see Chart 1) and its effect on mother’s milk and babies’ teeth were instrumental in the conclusion of the Partial Test Ban Treaty (PTBT) in 1963. The PTBT banned nuclear testing in the atmosphere, outer space and under water, but not underground, and was signed by the United States, the Soviet Union and the United Kingdom. However, France and China did not sign and conducted atmospheric tests until 1974 and 1980 respectively.

Although underground testing mitigated the problem of radiation doses from short-lived radionuclides such as iodine-131, large amounts of plutonium, iodine-129 and caesium-135 (See Chart 1) were released underground. In addition, exposure occurred beyond the test site if radioactive gases leaked or were vented.

Scientist arranging mice for radiation exposure investigations around 1944. (While conducting these experiments, the carcinogenesis of urethane was discovered).

Gradual increase in knowledge about dangers of radiation exposure

Over the past century, there has been a gradual accumulation of knowledge about the hazards of radioactivity. It was recognized early on that exposure to a sufficient radiation dosage could cause injuries to internal organs, as well as to the skin and the eyes.

According to the 2000 Report of the United Nations Scientific Committee on the Effects of Atomic Radiation to the UN General Assembly, radiation exposure can damage living cells, killing some and modifying others. The destruction of a sufficient number of cells will inflict noticeable harm on organs which may result in death. If altered cells are not repaired, the resulting modification will be passed on to further cells and may eventually lead to cancer. Modified cells that transmit hereditary information to the offspring of the exposed individual might cause hereditary disorders. Vegetation can also be contaminated when fallout is directly deposited on external surfaces of plants and absorbed through the roots. Furthermore, people can be exposed when they eat meat and milk from animals grazing on contaminated vegetation.

Radiation exposure has been associated with most forms of leukaemia, as well as cancer of the thyroid, lung and breast.

girl who lost her hair after being exposed to radiation from the bomb dropped on Hiroshima on 6 August 1945.

Studies reveal link between nuclear weapon testing and cancer

The American Cancer Society’s website explains how ionizing radiation, which refers to several types of particles and rays given off by radioactive materials, is one of the few scientifically proven carcinogens in human beings. Radiation exposure has been associated with most forms of leukaemia, as well as cancer of the thyroid, lung and breast. The time that may elapse between radiation exposure and cancer development can be anything between 10 and 40 years. Degrees of exposure regarded as tolerable in the 1950s are now recognized internationally as unsafe.

An article featured in Volume 94 of American Scientist onFallout from Nuclear Weapons Tests and Cancer Risksstates that a number of studies of biological samples (including bone, thyroid glands and other tissues) have provided increasing proof that specific radionuclides in fallout are implicated in fallout-related cancers.

It is difficult to assess the number of deaths that might be attributed to radiation exposure from nuclear testing. Some studies and evaluations, including an assessment by Arjun Makhijani on the health effects of nuclear weapon complexes, estimate that cancer fatalities due to the global radiation doses from the atmospheric nuclear testing programmes of the five nuclear-weapon States amount to hundreds of thousands. A 1991 study by the International Physicians for the Prevention of Nuclear War (IPPNW)estimated that the radiation and radioactive materials from atmospheric testing taken in by people up until the year 2000 would cause 430,000 cancer deaths, some of which had already occurred by the time the results were published. The study predicted that roughly 2.4 million people could eventually die from cancer as a result of atmospheric testing.

CHART 1 – EFFECTS OF RADIONUCLIDES

Radionuclide Half-life* Health hazards
Xenon
(Xe)		 6.7 hours Inhalation in excessive concentrations can result in dizziness, nausea, vomiting, loss of consciousness, and death. At low oxygen concentrations, unconsciousness and death may occur in seconds without warning.
Americium-241
(241Am)		 432 years Moves rapidly through the body after ingestion and is concentrated within the bones for a long period of time. During this storage americium will slowly decay and release radioactive particles and rays. These rays can cause alteration of genetic materials and bone cancer.
Iodine-131
(131I)		 8 days When present in high levels in the environment from radioactive fallout, I-131 can be absorbed through contaminated food. It also accumulates in the thyroid gland, where it can destroy all or part of the thyroid. May cause damage to the thyroid as it decays. Thyroid cancer may occur.
Caesium-137
(137Cs)		 30 years After entering the body, caesium is distributed fairly uniformly through the body, with higher concentration in muscle tissue and lower concentration in bones. Can cause gonadal irradiation and genetic damage.
Krypton-85
(85Kr)		 10.76 years Inhalation in excessive concentrations can result in dizziness, nausea, vomiting, loss of consciousness, and death.
Strontium-90
(90Sr)		 28 years A small amount of strontium 90 is deposited in bones and bone marrow, blood and soft tissues when ingested. Can cause bone cancer, cancer of nearby tissues, and leukaemia.
Plutonium-239
(239Pu)		 24,400 years Released when a plutonium weapon is exploded. Ingestion of even a miniscule quantity is a serious health hazard and can cause lung, bone, and liver cancer. The highest doses are to the lungs, the bone marrow, bone surfaces, and liver.
Tritium
(3H)		 12 years Easily ingested. Can be inhaled as a gas in the air or absorbed through the skin. Enters soft tissues and organs. Exposure to tritium increases the risk of developing cancer. Beta radiation emitted by tritium can cause lung cancer.

* ( i.e. amount of time it takes for half of the quantity of a radioactive material to decay)

Marie Curie won the Nobel Prize in chemistry in 1911 for her discovery of the elements radium and polonium. The curie unit is named after Marie and Pierre Curie, who conducted pioneering research on radiation.

Measuring radiation doses and biological risks

Scientists use different terms when measuring radiation. The terms can either refer to radiation from a radioactive source, the radiation dose absorbed by a person, or the risk that a person will suffer health effects from exposure to radiation. When a person is exposed to radiation, energy is deposited in the body’s tissues. The amount of energy deposited per unit of weight of human tissue is called the absorbed dose. This is measured using the rad or the SI Gy. The rad, which stands for radiation absorbed dose, has largely been replaced by the Gy. One Gy is equal to 100 rad.

The curie (symbol Ci) is a unit of radioactivity. It has largely been replaced by the Becquerel, which is the unit of radioactivity. One Becquerel is defined as the number of atoms which decay per second in a sample. The curie unit is named after Marie and Pierre Curie, who conducted pioneering research on radiation.

A person’s biological risk (i.e. the risk that a person will suffer health effects from an exposure to radiation) is measured using the conventional unit rem or the SI unit Sv.

CHART 2. EFFECTS OF DIFFERENT LEVELS OF RADIATION

Radiation dose in rems Health impact
5-20 Possible chromosomal damage.
20-100 Temporary reduction in number of white blood cells. Mild nausea and vomiting. Loss of appetite. Fatigue, which may last up to four weeks. Greater susceptibility to infection. Greater long-term risk of leukaemia and lymphoma is possible.
100-200 Mild radiation sickness within a few hours: vomiting, diarrhea, fatigue; reduced resistance to infection. Hair loss. In sufficient amounts, I-131 can destroy all or part of the thyroid gland, leading to thyroid abnormalities or cancer. Temporary male sterility.
200-300 Serious radiation sickness effects as in 100-200 rem. Body cells that divide rapidly can also be destroyed. These include blood cells, gastrointestinal tract cells, reproductive cells, and hair cells. DNA of surviving cells is also damaged.
300-400 Serious radiation sickness. Bone marrow and intestine destruction. Haemorraging of the mouth.
400-1000 Acute illness, possible heart failure. Bone marrow almost completely destroyed. Permanent female sterility probable.
1000-5000 Acute illness, nerve cells and small blood vessels are destroyed. Death can occur in days.

 

Severe Nuclear Reactor Accidents Likely Every 10 to 20 Years, European Study Suggests (Science Daily)

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ScienceDaily (May 22, 2012) — Western Europe has the worldwide highest risk of radioactive contamination caused by major reactor accidents.

Global risk of radioactive contamination. The map shows the annual probability in percent of radioactive contamination by more than 40 kilobecquerels per square meter. In Western Europe the risk is around two percent per year. (Credit: Daniel Kunkel, MPI for Chemistry, 2011)

Catastrophic nuclear accidents such as the core meltdowns in Chernobyl and Fukushima are more likely to happen than previously assumed. Based on the operating hours of all civil nuclear reactors and the number of nuclear meltdowns that have occurred, scientists at the Max Planck Institute for Chemistry in Mainz have calculated that such events may occur once every 10 to 20 years (based on the current number of reactors) — some 200 times more often than estimated in the past. The researchers also determined that, in the event of such a major accident, half of the radioactive caesium-137 would be spread over an area of more than 1,000 kilometres away from the nuclear reactor. Their results show that Western Europe is likely to be contaminated about once in 50 years by more than 40 kilobecquerel of caesium-137 per square meter. According to the International Atomic Energy Agency, an area is defined as being contaminated with radiation from this amount onwards. In view of their findings, the researchers call for an in-depth analysis and reassessment of the risks associated with nuclear power plants.

The reactor accident in Fukushima has fuelled the discussion about nuclear energy and triggered Germany’s exit from their nuclear power program. It appears that the global risk of such a catastrophe is higher than previously thought, a result of a study carried out by a research team led by Jos Lelieveld, Director of the Max Planck Institute for Chemistry in Mainz: “After Fukushima, the prospect of such an incident occurring again came into question, and whether we can actually calculate the radioactive fallout using our atmospheric models.” According to the results of the study, a nuclear meltdown in one of the reactors in operation worldwide is likely to occur once in 10 to 20 years. Currently, there are 440 nuclear reactors in operation, and 60 more are planned.

To determine the likelihood of a nuclear meltdown, the researchers applied a simple calculation. They divided the operating hours of all civilian nuclear reactors in the world, from the commissioning of the first up to the present, by the number of reactor meltdowns that have actually occurred. The total number of operating hours is 14,500 years, the number of reactor meltdowns comes to four — one in Chernobyl and three in Fukushima. This translates into one major accident, being defined according to the International Nuclear Event Scale (INES), every 3,625 years. Even if this result is conservatively rounded to one major accident every 5,000 reactor years, the risk is 200 times higher than the estimate for catastrophic, non-contained core meltdowns made by the U.S. Nuclear Regulatory Commission in 1990. The Mainz researchers did not distinguish ages and types of reactors, or whether they are located in regions of enhanced risks, for example by earthquakes. After all, nobody had anticipated the reactor catastrophe in Japan.

25 percent of the radioactive particles are transported further than 2,000 kilometres

Subsequently, the researchers determined the geographic distribution of radioactive gases and particles around a possible accident site using a computer model that describes Earth’s atmosphere. The model calculates meteorological conditions and flows, and also accounts for chemical reactions in the atmosphere. The model can compute the global distribution of trace gases, for example, and can also simulate the spreading of radioactive gases and particles. To approximate the radioactive contamination, the researchers calculated how the particles of radioactive caesium-137 (137Cs) disperse in the atmosphere, where they deposit on Earth’s surface and in what quantities. The 137Cs isotope is a product of the nuclear fission of uranium. It has a half-life of 30 years and was one of the key elements in the radioactive contamination following the disasters of Chernobyl and Fukushima.

The computer simulations revealed that, on average, only eight percent of the 137Cs particles are expected to deposit within an area of 50 kilometres around the nuclear accident site. Around 50 percent of the particles would be deposited outside a radius of 1,000 kilometres, and around 25 percent would spread even further than 2,000 kilometres. These results underscore that reactor accidents are likely to cause radioactive contamination well beyond national borders.

The results of the dispersion calculations were combined with the likelihood of a nuclear meltdown and the actual density of reactors worldwide to calculate the current risk of radioactive contamination around the world. According to the International Atomic Energy Agency (IAEA), an area with more than 40 kilobecquerels of radioactivity per square meter is defined as contaminated.

The team in Mainz found that in Western Europe, where the density of reactors is particularly high, the contamination by more than 40 kilobecquerels per square meter is expected to occur once in about every 50 years. It appears that citizens in the densely populated southwestern part of Germany run the worldwide highest risk of radioactive contamination, associated with the numerous nuclear power plants situated near the borders between France, Belgium and Germany, and the dominant westerly wind direction.

If a single nuclear meltdown were to occur in Western Europe, around 28 million people on average would be affected by contamination of more than 40 kilobecquerels per square meter. This figure is even higher in southern Asia, due to the dense populations. A major nuclear accident there would affect around 34 million people, while in the eastern USA and in East Asia this would be 14 to 21 million people.

“Germany’s exit from the nuclear energy program will reduce the national risk of radioactive contamination. However, an even stronger reduction would result if Germany’s neighbours were to switch off their reactors,” says Jos Lelieveld. “Not only do we need an in-depth and public analysis of the actual risks of nuclear accidents. In light of our findings I believe an internationally coordinated phasing out of nuclear energy should also be considered ,” adds the atmospheric chemist.

Radiação vaza em indústria nuclear no Rio (Correio Braziliense)

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JC e-mail 4367, de 19 de Outubro de 2011.

Ocorreram três vazamentos dentro da Fábrica de Combustível Nuclear, pertencente ao governo federal, em Resende (RJ). Dois deles, envolvendo substâncias químicas. Outro, urânio enriquecido altamente radioativo. A empresa admite “falhas”, mas descarta danos a funcionários e ao meio ambiente

Produto radioativo vaza em indústria nuclear de Resende (RJ). A empresa, pertencente ao governo federal, confirma o caso, reconhece “falhas” em equipamentos, mas descarta danos aos funcionários e ao meio ambiente

Engenheiros e técnicos de segurança do trabalho detectaram três vazamentos dentro da Fábrica de Combustível Nuclear (FCN), em Resende (RJ), dois deles envolvendo substâncias químicas e um de urânio enriquecido (UO2), elemento altamente radioativo. A constatação dos vazamentos foi comunicada pelos engenheiros e técnicos a seus superiores por e-mails internos. O Correio teve acesso a cópias desses e-mails.

O pó de urânio vazou de um equipamento chamado homogeneizador e caiu no piso da sala. O episódio foi registrado em 14 de julho de 2009. Em janeiro de 2010, o alarme de atenção da fábrica foi acionado em razão do vazamento de gás liquefeito usado no forno que queima os excessos de gases resultantes da produção de pastilhas de urânio. E, em julho deste ano, um engenheiro suspeitou do vazamento de amônia e comunicou o ocorrido aos gerentes.

Os três casos não representaram riscos aos trabalhadores, ao meio ambiente e ao funcionamento da fábrica, garantem a diretoria da fábrica – pertencente ao governo federal – e a presidência da Comissão Nacional de Energia Nuclear (Cnen), órgão responsável pela fiscalização de atividades radioativas no Brasil. “O urânio ficou numa sala confinada, hermeticamente fechada, não foi para o meio ambiente”, diz o diretor de Produção de Combustível Nuclear da FCN, Samuel Fayad Filho. Ele reconhece “falhas” nos equipamentos e diz que “todos os procedimentos foram tomados” em relação aos problemas detectados. “Não há vazamento de material radioativo em Resende”, assegura.

O Correio consultou especialistas para saber o que significam as informações que circularam internamente na FCN. Para o engenheiro nuclear Aquilino Senra, “é evidente que houve uma falha”. “Não era para o pó de UO2 sair dessa prensa”, diz o engenheiro nuclear, vice-diretor do Instituto Alberto Luiz Coimbra de Pós-Graduação e Pesquisa de Engenharia (Coppe), da Universidade Federal do Rio de Janeiro. “É uma anormalidade clara o vazamento de UO2 da prensa e a presença da substância no solo.”

Em relação ao vazamento de gás liquefeito, Aquilino afirma que “gás vazado não é boa coisa”. “Detectores existem para isso, mas o ponto é por que o gás vazou.” O Correio ouviu também um técnico ligado à Presidência da República, sob a condição de anonimato: “Não me parece um problema grave, pois a Presidência não foi avisada”, diz.

Funções – A FCN é um conjunto de fábricas responsáveis pela montagem do elemento combustível, pela fabricação do pó e da pastilha de urânio e por uma pequena parte do enriquecimento de urânio. O mineral é extraído em Caetité (BA). O processo de enriquecimento é feito quase todo fora do país, mas parte dele já ocorre na FCN. Cabe à fábrica, além dessa pequena fatia do enriquecimento, produzir as pastilhas que serão utilizadas na geração de energia nuclear pelas usinas Angra 1 e Angra 2, em Angra dos Reis (RJ).

Hoje, a FCN é responsável pelo enriquecimento de 10% do urânio necessário para Angra 1 e de 5% para Angra 2, segundo Samuel Fayad. A FCN faz parte da estatal Indústrias Nucleares do Brasil (INB), subordinada ao Ministério de Ciência, Tecnologia e Inovação (MCT).

O episódio do vazamento de pó de urânio foi relatado por um técnico de segurança do trabalho às coordenações superiores. A Cnen confirmou ao Correio o alerta. “O fato é irrelevante em termos de segurança. O referido pó foi identificado em área controlada, dentro de ambiente com contenção para material radioativo, não afetando trabalhadores da unidade ou o meio ambiente”, sustenta o órgão, por meio da assessoria de imprensa.

Crise – O setor de geração de energia nuclear vive um conflito e uma crise dentro do governo federal. O presidente da Comissão Nacional de Energia Nuclear (Cnen), Angelo Padilha, assumiu o cargo em 7 de julho, depois de o ministro da Ciência e Tecnologia, Aloizio Mercadante, demitir Odair Dias Gonçalves. Odair perdeu o cargo após revelações de que a usina Angra 2 operou por 10 anos sem licença definitiva e de que o Brasil passou a importar urânio em razão de licenças travadas. Até agora, a Agência Reguladora de Energia Nuclear é apenas um projeto, em razão de conflitos dentro do setor. A agência vai retirar da Cnen – principal acionista das Indústrias Nucleares do Brasil – a função de regulação e fiscalização.