TOKYO (Reuters) - The operator of Japan's Fukushima Daiichi nuclear power plant said on Friday it lost the ability to cool radioactive fuel rods in one of the plant's crippled reactors for about three hours earlier in the day.TOKYO | Fri Apr 5, 2013 11:21am EDT
It was the second failure of the system to circulate seawater to cool spent fuel rods at the plant in the past three weeks.
Tokyo Electric Power Co (Tepco) said it was alerted by an alarm that the cooling system for the No. 3 reactor had shut down at around 2:27 p.m. (0527 GMT) after a power board failed. Technicians fixed the problem by about 5:20 p.m., the utility said.
Tepco said workers appeared to have had inadvertently caused the power outage on Friday when they were trying to install a net to keep small animals from crawling into the reactor building.
A rat caused a power outage at Fukushima last month when it triggered a circuit breaker by bumping into exposed wires. In that case, the cooling system was shut down for almost a day.
The utility has faced a range of problems with controlling ground water and maintaining the massive cooling system built to keep the reactors stable.
The plant was the site of the worst nuclear disaster since Chernobyl in March 2011 when a magnitude 9.0 earthquake triggered a tsunami that destroyed back-up generators at Fukushima and disabled the plant's cooling system. Three of the reactors melted down.
Work to decommission the plant is projected to take decades to complete.
(Reporting by Kevin Krolicki; editing by Jason Neely)
5 April 2013 Last updated at 05:39 ETPower has been restored to part of the cooling system at Japan's tsunami-hit Fukushima nuclear plant, after it failed for the second time in a month.
The breakdown was not thought to pose any immediate danger, operator Tokyo Electric Power (Tepco) said.
An alarm at reactor number three earlier revealed the system had stopped at one of the pools containing spent, but highly radioactive, fuel rods.
Last month a power cut shut cooling systems for four spent fuel ponds.
The ponds cool the fuel - which generates intense heat - and provide shielding from radiation. The spent fuel remains in the ponds for a year or more.
Friday's breakdown at the Fukushima Daiichi nuclear plant lasted around three hours, Tepco said.
Officials discovered the system failure after an alarm sounded at reactor number three.
As of 14:00 local time (05:00 GMT) on Friday, the temperature of water inside the cooling pool at reactor 3 was 15.1C, well below the safety limit of 65C, Tepco said.
This indicated that the spent fuel remained stable and did not pose an immediate danger to the environment, news agency AFP quoted Tepco as saying.
The power cut last month shut down cooling systems for four spent fuel ponds at reactors 1, 3 and 4, although cooling for the reactors themselves was not affected.
The company said a rat had damaged the electrics, causing a short circuit in a switchboard and triggering the power cut.
On 11 March 2011, an earthquake and tsunami crippled the plant. Waves knocked out cooling systems for the reactors, leading to meltdowns at three of them.
Engineers have since stabilised the plant but years of work lie ahead to fully contain the disaster and tackle its effects.
Tens of thousands of evacuees remain unable to return home.
A empresa de energia que explora a central nuclear de Fukushima, no Japão, a Tokyo Electric Power Co, reconheceu este sábado que cerca de 120 toneladas de água radioactiva vazaram de um dos tanques, contaminando o solo circundante. O problema vai levar duas semanas a ser resolvido.
Em conferência de imprensa, a empresa informou que ainda está por descobrir a causa do vazamento de um dos sete tanques subterrâneos que armazenam a água usada para arrefecer os reactores nucleares – os tanques são compostos por três camadas que deveriam impedir a saída da água.
Elementos radioactivos foram detectados em água colhida no solo ao redor de um tanque e da camada externa de um fundo impermeável do tanque, disse um porta-voz da empresa.
Para já, a Tokyo Electric Power planeia bombear 13 mil metros cúbicos da água remanescente no tanque afectado para outros, durante as próximas duas semanas. Não é expectável que a água radioactiva que entretanto saiu chegue ao mar, embora o tanque esteja localizado a 800 metros da costa. A empresa não divulga durante quanto tempo o tanque esteve a vazar.
De recordar que a central de Fukushima tem enfrentado uma série de problemas com o controlo de água do solo e manutenção do sistema de refrigeração, construído para manter os reactores nucleares estáveis. Ainda esta sexta-feira, a empresa deu conta de uma interrupção do sistema de refrigeração da piscina de resfriamento de combustível gasto de um dos reactores. E, em meados do mês passado, um rato causou um curto-circuito afectando os sistemas de arrefecimento do combustível nuclear.
A central nuclear foi um dos locais mais afectados com o terramoto de Março de 2011 no Japão.
Já lá vão cerca de dois anos desde o acidente nuclear de Fukushima, que desalojou dezenas de milhar de pessoas, mas só agora é possível a qualquer um ver o que se passa numa das cidades evacuadas, Namie.
A Google, a convite do presidente da Câmara de Namie, Tamotsu Baba, publicou imagens a 360 graus, no Google Street View, desta cidade deixada ao abandono por causa do sismo e tsunami de Março de 2011 e dos níveis de radiação que ainda hoje se fazem sentir na zona.
As imagens revelam uma cidade fantasma como aquelas que vemos em filmes de ficção: casas destruídas ao abandono, lojas, restaurantes e tudo mais o que uma zona urbana tem – tudo excepto pessoas. Há também carros capotados e barcos arrastados pelo tsunami.
"Desde o desastre, o resto do mundo tem avançado e muitos sítios no Japão já começaram a recuperar. Mas em Namie o tempo continua parado”, diz Tamotsu Baba, num texto publicado no blogue japonês da Google.
Cerca de 160 mil pessoas que tiveram de abandonar as suas casas devido ao acidente nuclear de Fukushima ainda vivem em residências temporárias e podem ter de esperar décadas até regressar em segurança. Só em Namie, 21 mil pessoas tiveram de deixar a cidade.
Este projecto surgiu depois de "muitas das pessoas realojadas" pedirem para ver o estado actual da cidade, escreveu Tamotsu Baba. "Nós, das gerações mais velhas, sentimos que recebemos esta cidade dos nossos antepassados, e sentimos profunda mágoa por não a podermos passar aos nossos filhos", lamenta o presidente da Câmara. Mas acrescenta que o dever passa agora por garantir que as futuras gerações compreendem a história e a cultura da cidade, "mesmo aqueles que não se vão lembrar do acidente nuclear de Fukushima".
A esola primária de Ukedo também foi fortemente afectada pelo sismo, e é uma das preocupações demonstradas pelo peresidente da Câmara de Namie.
Apesar do cenário não ser favorável a muitos, já há pessoas autorizadas a regressar a casa.
Estas imagens estão disponíveis desde quarta-feira no Google Maps e num site criado para relembrar os acontecimentos de 2011, chamado Memórias para o Futuro.
Um simples rato terá sido a causa de uma falha, esta semana, nos sistemas de arrefecimento do combustível nuclear da central de Fukushima, no Japão, que deixaram de funcionar por mais de um dia.
Ao fim da tarde de segunda-feira (manhã em Portugal), um corte na electricidade interrompeu o funcionamento dos sistemas de arrefecimento nas piscinas com resíduos nucleares de três reactores da central e numa quarta piscina comum a todo o complexo. A situação foi normalizada aos primeiros minutos desta quarta-feira, horário do Japão.
Técnicos da Tepco – a empresa que opera a central nuclear – encontraram um pequeno animal, possivelmente um rato, morto junto de um quadro eléctrico com sinais de queimado. Segundo a empresa, o animal deverá ter tocado no quadro, provocando um curto-circuito.
Foi o suficiente para desligar no total nove sistemas eléctricos, causando um novo incidente na central de Fukushima, palco em 2011 do segundo maior acidente do uso civil da energia nuclear, apenas superado por Tchernobil, na Ucrânia, em 1986.
Nos reactores 1,3 e 4, a falha eléctrica desta semana afectou o arrefecimento das piscinas onde estão depositados sobretudo combustível nuclear usado. O mesmo aconteceu numa quarta piscina, que serve de depósito comum aos seis reactores de Fukushima.
Segundo a Tepco, a temperatura da água nas piscinas esteve longe de atingir o limite de segurança de 65 graus Celsius. O principal risco seria a água entrar em ebulição, evaporando e eventualmente deixando as barras de combustível em contacto com o ar e a aquecer.
A preocupação maior era com a piscina do reactor 4, a mais carregada de material radioactivo, com 1300 barras de combustível usado e também com 200 barras de combustível não utilizado.
O sismo e o tsunami que abalaram o Japão há dois anos provocaram um grave acidente nuclear em Fukushima. O tsunami destruiu os sistemas de arrefecimento, afectando gravemente quatro reactores. Houve duas explosões, fusão de combustível nuclear e libertação de radioactividade. As piscinas com o combustível usado também foram afectadas. Desde então, Fukushima e quase todas as outras centrais nucleares do Japão estão encerradas.
Las flechas rojas indican deformaciones e irregularidades en las alas.
La exposición a material radioactivo tras el desastre de Fukushima causó mutaciones en las mariposas de Japón, según un nuevo estudio.
Las mariposas recolectadas luego del accidente muestran cambios en la longitud de sus patas y antenas, así como en la forma de las alas.
"Se pensaba que los insectos eran muy resistentes a la radiación. Nuestros resultados fueron inesperados"
Joji Otaki, Universidad Ryukyus, Okinawa.
De acuerdo a los autores del estudio, el vínculo entre las mutaciones y el material radioactivo quedó demostrado en experimentos de laboratorio.
"Se pensaba que los insectos eran muy resistentes a la radiación", dijo a la BBC el investigador principal, Joji Otaki, de la Universidad Ryukyus en Okinawa.
"En este sentido, nuestros resultados fueron inesperados".
Ojos irregulares
Dos meses después del accidente en la planta nuclear Daiichi en Fukushima en marzo de 2011, un equipo de investigadores japoneses recolectó 144 ejemplares adultos de la especie Zizeeria maha, en 10 localidades diferentes incluyendo Fukushima.
Cuando el desastre tuvo lugar, las mariposas se encontraban en estado larval.
Ojos con hundimientos. El número de mutaciones es mayor en las zonas más próximas a Fukushima.
Los científicos constataron que en las zonas de mayor radiación las mariposas tenían alas anormalmente pequeñas y ojos desarrollados en forma irregular.
Otaki y sus colegas crearon un programa de reproducción de esos ejemplares en laboratorios a unos 1.750 kms del lugar del accidente, en sitios con radiación prácticamente no detectable.
Fue en estas nuevas generaciones que los científicos comenzaron a constatar anormalidades en las antenas, que cumplen un papel crucial para la exploración del hábitat y la búsqueda de pareja.
Seis meses después, los científicos recolectaron nuevamente mariposas de las mismas 10 localidades y encontraron que el número de mutaciones en los ejemplares del área de Fukushima era más del doble del de otros sitios.
Los investigadores concluyeron que el alto índice de mutaciones se debió no sólo a que las mariposas ingirieron alimentos contaminados, sino al material genético recibido de la generación previa que no presentaba anormalidades morfológicas.
Indicadores ambientales
La imagen muestra una antena más corta y deforme.
Otaki y su equipo han venido estudiando esta especie durante 10 años. Las mariposas son particularmente sensibles a cambios en el hábitat y los científicos planeaban utilizarlas como un indicador ambiental, incluso antes del accidente.
"Ya veníamos estudiando cambios en los patrones de colores de las alas en respuesta al calentamiento global. Como esta especie puede ser hallada además en jardines y parques públicos, puede ser utilizada para monitorear ambientes urbanos", dijo a la BBC el investigador.
El nuevo estudio deja en claro que aún después del decaimiento del material radioactivo, el desarrollo de los animales sigue siendo afectado.
"Ya veníamos estudiando cambios en los patrones de colores de las alas en respuesta al calentamiento global. Como esta especie puede ser hallada además en jardines y parques públicos, puede ser utilizada para monitorear ambientes urbanos"
"Este estudio es fundamental por sus implicaciones para las comunidades tanto biológica como humana en Fukushima", dijo Tim Mousseau, biólogo de la Universidad de Carolina del Sur en Estados Unidos, quien estudia el impacto de la radiación en los animales y las plantas tanto en Chernobyl como en Fukushima.
"Las mutaciones y anomalías sólo puede ser explicadas por la exposición a material radioactivo", agregó Mousseau.
Otras investigaciones previas ya habían apuntado la importancia de las aves y mariposas como indicadores del impacto a largo plazo de contaminantes radioactivos.
El estudio fue publicado en la revista Scientific Reports.
A divulgação do resultado das análises efetuadas ocorre dois meses depois de ter sido remotada, ainda que de forma parcial, a atividade da pesca na província de Fukushima. Desde então, já é possível, pela primeira vez desde o acidente nuclear, encontrar peixe nos supermercados. Também o polvo de Fukushima voltou a ser cotado no maior mercado de peixe do mundo, o Tsukiji, em Tóquio.
A Tepco, que opera a central de Fukushima, já garantiu que vai continuar as análises a peixes e mariscos na região até ao final de setembro.
A empresa proprietária da central nuclear de Fukushima revelou ter detectado um nível de radioactividade recorde, 258 vezes superior ao limite fixado pelo Governo, em dois peixes marinhos capturados ao largo da central.
Os peixes foram capturados para recolha de amostras a 1 de Agosto a 15 metros de profundidade e a 20 quilómetros da costa, no nordeste do Japão. Segundo a Tepco (Tokyo Electric Power Company), uma avaliação científica revelou um nível de 25.800 becquerels de césio radioactivo por quilo, ou seja, 258 vezes superior ao limite fixado pelo Governo para os alimentos de consumo (100 becquerels por quilo).
Este valor foi confirmado pela Agência de Pescas nipónica. O anterior recorde de radioactividade registado era de 18.700 becquerels de césio por quilo, detectado em salmões ao largo de Fukushima.
A Tepco adiantou que, nas próximas semanas, vai realizar novas análises a peixes e ao ambiente onde vivem para determinar as causas de um tal nível de radioactividade.
Desde Junho, os pescadores estão autorizados a capturar, a título experimental, várias espécies de peixe e de medusas mas apenas nas zonas situadas a mais de 50 quilómetros da central nuclear, onde se verificou o acidente a 11 de Março de 2011 depois de um tsunami ter danificado os sistemas de arrefecimento.
Na semana passada, investigadores japoneses anunciaram que os seus trabalhos demonstram que as borboletas que vivem perto da central de Fukushima têm mutações relacionadas com a radioactividade.
A catástrofe de Fukushima obrigou milhares de habitantes da região a abandonar as suas casas.
A catástrofe nuclear na central nuclear de Fukushima, após o sismo e tsunami ocorridos a 11 de Março de 2011, foi um “desastre provocado pelo homem”, deliberou uma comissão de inquérito mandatada pelo Parlamento japonês.
“Apesar de espoletado por estes eventos catastróficos, o acidente subsequente na central nuclear de Fukushima Daiichi não pode ser considerado um desastre natural”, deliberou a comissão de peritos criada pelo Parlamento nipónico em Maio de 2011 para avaliar a gestão da crise e fazer recomendações.
A central nuclear de Fukushima Daiichi, com seis reactores nucleares, ficou seriamente danificada após o tsunami, causado por um sismo de magnitude 9 na escala de Richter, ter destruído os sistemas de arrefecimento dos reactores, levando a várias fusões em cadeia e à libertação de radioactividade. Foram necessários nove meses de trabalhos para declarar a central estabilizada. O acidente de Fukushima foi considerado o mais grave desde o acidente de Tchernobil, na Ucrânia, em 1986. Cerca de 150.000 pessoas, que moravam a 20 quilómetros da central ou em localidades contaminadas, foram forçadas a abandonar as suas casas devido aos riscos para a saúde. A radioactividade chegou a vários alimentos produzidos na província de Fukushima, principalmente legumes, vegetais e leite.
Nesta quinta-feira foi divulgado o relatório final, que sumariza a investigação ao acidente de Fukushima, um trabalho que começou em Dezembro de 2011 e incluiu 900 horas de entrevistas a mais de 1100 pessoas. O documento, com 641 páginas, conclui que o desastre “deveria e poderia ter sido previsto e prevenido” e os seus efeitos “mitigados por uma resposta humana mais eficiente”.
A catástrofe de Fukushima "é o resultado de um conluio entre o Governo, as agências de regulação e o operador Tepco (Tokyo Electric Power Company), e de uma falta de gestão naquelas mesmas instâncias", concluiu o relatório final. O documento apontou graves deficiências na actuação do Governo - nomeadamente do então primeiro-ministro Naoto Kan, que se demitiu no ano passado depois de críticas à forma como geriu a crise - e dos responsáveis da central nuclear. “Durante a investigação, a comissão encontrou uma ignorância e uma arrogância que não têm desculpa para qualquer pessoa ou organização que lide com energia nuclear."
Este painel de peritos considera que houve várias oportunidades perdidas e que a companhia responsável poderia ter adoptado medidas para evitar o acidente, vários anos antes de este acontecer. "A direcção da Tepco estava consciente dos atrasos nos trabalhos anti-sísmicos e nas medidas contra os tsunamis. Sabia que Fukushima Daiichi era vulnerável”, salientou a comissão.
Um inquérito anterior à catástrofe de Fukushima, mandatado pela Tepco, desculpou a companhia de electricidade de qualquer responsabilidade, afirmando que o forte sismo e a dimensão do tsunami ultrapassaram todas as previsões e não poderiam ter sido previstos. O relatório final desta comissão de inquérito considera que isso "parece ser uma desculpa para fugir às responsabilidades".
Além disso, a intervenção directa do gabinete do primeiro-ministro nos trabalhos de emergência na central nuclear provocou uma quebra na cadeia de comandos nas primeiras horas da crise. A mesma comissão de inquérito também culpou as convenções culturais e a relutância em questionar a autoridade como factores agravantes da catástrofe.
Agora, o relatório do painel de peritos recomenda a criação de um comité permanente para acompanhar o trabalho das autoridades reguladoras do sector da energia nuclear. Kiyoshi Kurokawa, coordenador da comissão, espera que estas conclusões sejam utilizadas para reforçar o sistema de regulamentação nuclear no futuro e ajudar as populações que foram desalojadas pelo acidente nuclear, noticiou a estação japonesa NHK.
Os peritos da comissão manifestaram alguma preocupação perante a possibilidade de o Japão vir a reactivar a sua rede de reactores nucleares (50) que, antes da catástrofe de Fukushima, eram responsáveis por 30% da electricidade consumida. Apenas um deles, na central Ohi - gerida pela companhia Kepco (Kansai Electric Power Company) - está em funcionamento. Este reactor foi reactivado nesta segunda-feira e começou hoje a produzir energia para a rede. De acordo com os peritos da comissão pode existir uma falha sísmica por baixo da central Ohi.
Mais de um ano depois do acidente nuclear de Fukushima, o Ministério do Ambiente japonês detectou elevados níveis de césio radioactivo em peixes de água doce nos rios e lagos daquela província.
As amostras foram recolhidas entre Dezembro e Fevereiro nos rios e lagos da província e ainda em oito locais do mar. Os níveis mais elevados de césio radioactivo, 2600 Becquerels por quilo, foram encontrados num peixe do rio que passa pelas cidades de Iitate e Minamisoma, a Norte da central atómica danificada pelo tsunami de 11 de Março de 2011.
Alguns insectos aquáticos, dos quais se alimentam alguns peixes, também registaram níveis de césio radioactivo, entre os 330 e os 670 Becquerels por quilo, noticia a estação nipónica NHK.
No mar, os níveis são mais baixos. Segundo o Ministério do Ambiente japonês, o nível mais elevado de césio radioactivo (260 Becquerels por quilo) foi detectado num peixe perto da cidade de Iwaki, a Sul da central de Fukushima.
O Ministério do Ambiente garante que vai monitorizar de perto os níveis de césio radioactivo nos peixes de água doce.
Neste sábado, um dos quatro reactores da central nuclear de Ohi, no Oeste do país, foi reiniciado. Até então, todos os 50 reactores nucleares japoneses estavam inoperacionais, na sequência do acidente na central atómica de Fukushima, originado pelo tsunami de 11 de Março de 2011.
Antes deste acidente, a energia nuclear era responsável por cerca de 30% da electricidade consumida no país. Na sexta-feira, milhares de pessoas saíram às ruas em protesto contra a energia nuclear. Os organizadores falam em 180.000 manifestantes e a polícia em 20.000.
One year after the Fukushima Daiichi nuclear power plant was crippled by a massive earthquake and tsunami, the surrounding area remains highly radioactive. The looming anniversary of the catastrophe has pushed TEPCO, the plant’s disgraced operators, to admit that the situation is still hazardous. Plant director Takeshi Takahashi said last week that the company was doing “the best it could” in order to allow local residents to move back “as quickly as possible”. But he also admitted that while the station had reached “cold shutdown conditions", or a constant temperature of -100°C, it was still "rather fragile".
As Europe’s biggest nuclear producer, France has closely monitored the Japanese disaster. Two French specialists decode Takahashi’s statement.
"Reactors are still in meltdown"
Stéphane Lhomme, head of the French anti-nuclear organisation l’Observatoire nucléaire, says that TEPCO is seriously playing down potential dangers. “Their declarations are over-confident, and moreover, simply not true,” he told FRANCE 24. “The plant is neither stable nor fragile.” Lhomme describes the current situation as “catastrophic. Even if the thermal power in the four damaged reactors has been considerably reduced, they are still in meltdown and therefore still noxious.” Speaking with an alarmed tone, he says “of course the global situation is slightly better than it was a year ago. But the corium, a lava-like fuel-containing material that lies at the bottom of the containers, remains a real problem.”
Lhomme argues that at several thousand degrees, this molten lava could break through the cask at any point and destroy the concrete beneath the container, reaching soil and water located beneath the surface. “If it comes into contact with water, the corium would spark a series of massive vapour cloud explosions,” warns Lhomme.
Authorities working round the clock
Thierry Charles, security director of the French Institute of Radio-Protection and Nuclear Safety (IRSN), agrees that the remaining corium could pose a threat. “We don’t even know how much corium each cask contains,” he explains, “or how much could get through several metres of concrete.”
However, Charles is more optimistic than his colleague. “The plant is still leaking in some places and so remains fragile,” he admits. “But the situation can’t be compared with what it was a year ago. The Japanese authorities have already done plenty to tackle the problem. They have injected a cement substance into the floor of the plant, removed the debris, blocked off potential seepage points, cleaned the floors and dressed Reactor 1 in a metal cover in order to limit any fallout.”
Charles dismisses the global hysteria over radiation levels. “The main leakages happened from 12 to 25 March 2011,” he explains. “Except for caesium, most of the particles released only have a short lifespan. They lose half their strength very quickly, from within a few hours to eight days depending on the type of iodine. So except for the 30km surrounding the plan, we’re only at risk in the first few weeks after an accident.”
‘Decades before locals can move back’
Charles agrees that there is still work to do. The site must be progressively dismantled – a highly technical and expensive operation. The area surrounding the plant must also be decontaminated for local residents to be able to return home, which could take decades according to both scientists.
“It’s going to take around 30 years to completely decommission the site and ensure it’s non-hazardous,” explains Stéphane Lhomme. “After that, it will be even longer before the locals can return.” Lhomme says that the equivalent of 408 million-billion radioactive Becquerel particles lie within 30 kilometres of the plant, which itself remains a wasteland.
Even Charles agrees that the radiation levels are too high in the evacuated areas. “These places are most definitely uninhabitable,” he states.
Protestos em todo o mundo contra a energia nuclear
(AFP) – 11/03/2012
PARIS, França — Um ano após a catástrofe na central de Fukushima, no Japão, milhares de pessoas mobilizaram-se neste domingo, em várias partes do mundo, em protesto contra a energia nuclear.
Na Alemanha, país que decidiu abandonar progressivamente a energia atômica, após o terremoto e o tsunami que destruíram os reatores de Fukushima, cerca de 3.000 pessoas fizeram um círculo em torno da central de Brokdorf (norte), segundo os organizadores. Protestos também foram observados perto dos reatores alemães de Gundremmingen (sul), Neckarwestheim (sul) e Grohnde (norte).
Na França, a nação mais dependente do mundo em energia nuclear (75% da eletricidade produzida no país), uma corrente humana reuniu 60 mil pessoas, segundo os organizadores da manifestação.
Vindos de Alemanha, Suíça, Bélgica e de toda a França, os manifestantes se mobilizaram nos 230 km que separam Lyon (centro-leste) de Avignon (sul), ao longo do vale do Ródano, a região mais nuclearizada da 'Europa, com 14 reatores.
Cerca de 5.000 militantes participaram de uma caminhada de mais de uma hora, nas proximidades da central nuclear de Mühleberg, no oeste da Suíça. A passeata "Saiamos do nuclear" teve como objetivo pedir "a paralisação imediata das centrais de Mühleberg e de Beznau".
Após o acidente de Fukushima, as autoridades suíças recomendaram a não substituição dos cinco reatores em funcionamento, ao final de seu período de vida útil - até o ano de 2034.
Na Espanha, centenas de manifestantes se reuniram perto da central de Garona, no norte do país, para exigir seu fechamento. O governo decidiu prolongar por mais cinco anos o tempo de vida útil desta usina, a mais antiga do país.
Na Austrália, cerca de 500 manifestantes contra a energia nuclear reuniram-se perto das sedes dos grupos de mineração BHP Billiton e Rio Tinto em Melbourne, por iniciativa de uma associação de imigrantes japoneses chamada "japoneses pela paz".
"É muito importante para nós comemorar este dia, para que os australianos se lembrem do que aconteceu em Fukushima e do papel da Austrália como fornecedor importante de urânio ao Japão, aí compreendidos os reatores de Fukushima", declarou um dos organizadores, Kazuyo Preston.
A Austrália não é uma potência nuclear, mas o terceiro produtor mundial de urânio, atrás do Cazaquistão e do Canadá.
Em Taiwan, 5.000 manifestantes, segundo os organizadores, foram às ruas de Taipé para pedir o fechamento de três centrais nucleares "assim que possível", neste país regularmente abalado por sismos potentes.
Há um ano, um acidente nuclear maior foi registrado na central de Fukushima, depois de um terremoto seguido por tsunami, fazendo mais de 19.000 mortos e desaparecidos no nordeste do Japão.
Copyright © 2012 AFP. Todos os direitos reservados. Mais »
Comboios, metro e outros transportes pararam e o preto foi a cor predominante durante todo o dia no país, incluindo nas roupas do imperador Akihito e do primeiro-ministro do país, Yoshihiko Noda, que estiveram a presidir uma cerimónia em Tóquio.
Mesmo a recuperar-se de uma cirurgia no coração, o imperador fez questão de ler uma mensagem, em que disse que o Japão «nunca deve esquecer o que aconteceu, se o país quiser progredir para um futuro melhor e mais seguro».
Em Rikuzen Takata, na província de Miyagi, um pinheiro tornou- se o símbolo da reconstrução do país. A árvore, localizada de frente ao mar, foi a única que sobreviveu às ondas gigantes.
Por isso, foi cuidadosamente isolada e habitantes, voluntários e até autoridades fazem de tudo para que não morra devido à salinidade excessiva do solo. Sementes e mudas do pinheiro foram recolhidos para garantir que o laço sentimental dos japoneses com a árvore não se desfaça.
Entre os desafios do país estão dar um destino a uma gigantesca montanha de entulho: 23 milhões de toneladas, que segundo cálculos do governo devem ser processados até 2014.
Reconstruir as cidades e recuperar a economia local são outras tarefas das autoridades. Agricultores e pescadores, principalmente, não sabem quando poderão voltar a exercer as suas atividades.
«Não temos barcos, nem redes ou combustível para sair para alto mar para pescar», disse à BBC Takayuki Ueno, 44 anos. Ele, a mulher e um sócio conseguiram um espaço construído por uma organização sem fins lucrativos para vender o que sobrou dos peixes pescados no ano passado e que foram congelados.
«A gente calcula que essa situação só vai se normalizar dentro de dez anos», disse o pescador, que espera contar com a ajuda financeira do governo para poder sobreviver.
A imprensa local fez uma cobertura intensa, nunca vista no país. Mobilizaram equipas em praticamente todas as cidades atingidas pelo tsunami.
No dia 11 de março de 2011, um terramoto de 9.0 de magnitude atingiu a região nordeste do Japão. Cerca de 20 minutos depois, ondas gigantes, que chegaram a 40 metros de altura, destruíram as vilas e cidades ribeirinhas.
A pior tragédia natural já enfrentada pelos japoneses resultou na morte de 15.853 pessoas - maior perda de vidas desde a Segunda Guerra Mundial. Outras 3.283 pessoas foram dadas como desaparecidas e, passado um ano, as buscas ainda continuam, principalmente no mar e em áreas alagadas.
O desastre foi agravado depois de as ondas gigantes atingirem a central nuclear de Fukushima, causando um acidente nuclear. Mais de 80 mil famílias foram obrigadas a deixar as suas casas num raio de 30 quilómetros de distância da central.
A crise nuclear fez com o que Japão começasse a pesquisar outras fontes de energia e adotasse medidas mais rígidas de segurança para os 54 reatores nucleares instalados no país.
FOTOS INTERATIVAS:
VÍDEOS DO TSUNAMI:Yoshiko Ota não abre a janela e nunca estende a roupa no exterior. Com receio de problemas congénitos, avisa as filhas: "nunca tenham filhos."
Assim se vive com o fantasma da radioatividade, um ano depois do tsunami que desencadeou a posterior crise nuclear em Fukushima.
"O porta-voz do Governo está sempre a dizer que não há efeitos na saúde 'imediatos'", sublinha a professora, de 48 anos, em declarações à Associated Press. "Não fala do que vai passar-se daqui a 10 ou 20 anos. Deve achar que o povo de Fukushima é tolo", lamenta.
Ota toma comprimidos para acelerar o metabolismo, na esperança de expulsar a radiação do corpo. Para limitar a sua exposição à radioatividade, compra vegetais cultivados longe dali e gasta cerca de 100 euros por mês em água engarrafada.
Nem todos os residentes são tão cautelosos, mas respira-se inquietação. Muitos partiram. Os que ficaram sabem que vivem com um inimigo invisível.
A incerteza alimenta o medoQuase um anos depois, a central nuclear ainda emite radiação potencialmente perigosa, embora em níveis não comparáveis aos que se seguiram ao tsunami de 11 de março.
Alguns peritos dizem que os riscos para a saúde fora da zona interdita, que tem um raio de 20 quilómetros, são mínimos e que as pessoas podem tomar medidas simples para se protegerem, como não ingerir alimentos produzidos localmente, viver durante alguns períodos longe dali. Mas, para as crianças, ninguém sabe dizer qual o nível de exposição que pode ser considerado seguro.
Na cidade de Fukushima viviam 280 mil pessoas - algumas sairam, onde mudaram-se para as cidades vizinhas, como é o caso das 100 mil evacuadas por se encontrarem no tal raio de 20 quilómetros.
"As pessoas estão muito assustadas", garante Wolfgang Weiss, responsável pelo comité da ONU para os efeitos da radiação atómica, que está a estudar o caso de Fukushima.
O facto de o governo ter repetido que a uma exposição a 100 milisieverts era segura - e estudos terem demonstrado que esses níveis já implicam um risco de cancro - contribui para o ceticismo público. E para agravar o medo.
Fukushima farmer defies Japanese government order to destroy cattle. Link to this videoThe police officers guarding the entrance to Japan's nuclear evacuation zone barely glance at Yukio Yamamoto's permit before waving him through.
The 69-year-old cattle farmer has been making this journey several times a week for almost a year. Yamamoto is one of about 10 farmers from Namie who are defying government orders to euthanise their cattle, their market value obliterated by ingestion of radioactive caesium.
Nothing, he says, will stop him from carrying out what is almost certain to be the last duty of care to animals that have been his family's livelihood for generations. Not the nuclear contamination that has made his hometown of Namie uninhabitable; nor the piercing cold that blankets his farm on this winter afternoon. And definitely not the officials who dismiss his compassion as hopelessly misplaced.
Almost a year since the Fukushima Daiichi accident turned 930 square miles of land into a no-go zone, birdsong and the laboured groans of his 36 black-haired wagyu cows – animals once highly prized for their premium-quality beef – are the only signs of life near the farmhouse he once shared with his family.
Human activity has all but ceased since 80,000 residents living within 20km of Fukushima Daiichi fled their homes after the first reactor exploded, 24 hours after the plant was crippled by a 9.0-magnitude earthquake and tsunami.
Yamamoto, who obtained a permit allowing him to enter the nuclear evacuation zone to feed his animals, agreed to take the Guardian on a brief visit to his farm, which is 14km from the plant.
His route takes him past fields strewn with tsunami wreckage, still untouched, and through the centre of Namie, a town of that once housed 22,000 people but now lies abandoned.
Warnings about the imminent arrival of Fukushima Daiichi's toxic payload drove every last resident from their homes, and forced farmers to condemn their animals to slow, painful deaths from starvation.
The nuclear accident has inflicted serious damage to brand Fukushima and its annual $3.2bn (£1.57bn) farming industry, but Yamamoto refuses to believe that all is lost.
"I left like everyone else after 11 March," he said. "I couldn't stop worrying about my cows, so I started coming back in every other day to feed them." The round-trip from his temporary accommodation took six hours.
In May, the then prime minister, Naoto Kan, ordered the killing of livestock by lethal injection after radiation made them commercially worthless. Local farmers say the operation has been blighted by mishaps, including the escape of an estimated 1,000 cattle from their homesteads, and conflicting data on how many cows have been killed.
"Straight after the disaster, my cows had nothing to eat or drink ... many of them starved to death right where they were tethered," Yamamoto said. "I had to decide whether to leave the ones still alive or keep them healthy, even though we were separated."
But time could be running out for the animals whose survival has turned into a personal mission. In the year since the disaster, Yamamoto says he has not received any feed from the government; what little he has came from private donors, including farmers in Australia after they were approached by the country's meat and livestock office in Tokyo.
"Eventually the feed will run out, and the government has said it will kill every last cow," says Yamamoto, whose cows once fetched well over $10,000 per head. "But that is something I can't allow to happen. "I could never kill these cows. They are like members of my family."
He is pinning his hopes on studies being conducted by academics to gauge the level of contamination in livestock. "No one has said for sure if cows that eat and drink in Fukushima really are beyond help," he said. "We want someone to conduct a proper study."
"We accept that the meat will never go on sale, but the cows could be put to some other commercial use," says Ryoichi Harada, another rebel farmer who helps Yamamoto feed his animals.
As he leaves Namie at dusk, Yamamoto passes the entrance to another farm, the black figures of wagyu cows just visible on a distant ridge. At the entrance, animal skulls have been placed next to signs demanding that the authorities end the euthanasia programme.
The site has been hastily renamed Hope Farm, but in Yamamoto's voice there is only despair: "Japan is supposed to be an advanced nation, so how is it that we have forgotten to care for our animals?"
The remains of the shattered reactors are still some distance away when you first notice the sheer destruction of Japan's nuclear disaster. The journey into the heart of the world's worst nuclear crisis since Chernobyl 26 years ago begins much earlier, in the towns and villages that exist in name only, their residents having been sent fleeing a year ago.
Homes and shops lie empty, the roads are deserted. In the town of Naraha, groceries sit untouched on the shelves of a convenience store; a handful of cars punctuate a supermarket carpark, abandoned by their owners amid the panic that followed the first explosion at one of the Fukushima Daiichi plant's reactor buildings.
Most of the buildings that lie just inside the 12-mile (20km) nuclear evacuation zone – even the grand wooden homes – withstood the violent seismic shifts unleashed by a magnitude-9.0 earthquake on the afternoon of 11 March. But, as the Guardian witnessed on a rare trip to the nuclear plant, the destruction is more insidious than collapsed roofs and ruptured tarmac, but no less shocking. Almost everywhere, beeping monitors alert visitors to the invisible foe that has befouled entire communities: radiation.
Further into the evacuation zone, near a disused public relations office belonging to the plant's owner, Tokyo Electric Power (Tepco), radiation levels rise to 2 microsieverts/hour (the normal background level is 0.2-0.3). The readings soar to 35 microsieverts/hour in Okuma, a town near the plant's perimeter, where residents have been told their former homes could remain uninhabitable for decades.
Fukushima Daiichi covers a huge swath of land stretching from its hilltop entrance down to the coast, where its six reactors were easy targets for the 14-metre tsunami that roared ashore soon after the quake. From a vantage point to the south of the site it is easy to see the mangled innards of reactor buildings No 3 and 4 and, behind them, the vinyl shroud covering the No 1 reactor – the first unit to suffer a hydrogen explosion last March.
There are few signs of the 3,000 workers on site – a small portion of the many thousands of contractors and subcontractors who have joined the mission to save the plant from an even greater catastrophe. Pockets of workers in protective suits huddle around coiled pipes and hoses used to feed and recycle coolant to the damaged reactors. In the distance are rows of tanks containing tens of thousands of tonnes of radioactive water drawn from the reactors' flooded basements.
While temperatures inside the reactors have stayed below the required boiling point, radiation is still too high for workers to enter some areas. The utility's contamination map shows radiation inside reactor No 3 as high as 1,500 microsieverts/hour.
The world is in awe of the speed with which Japan has cleared tsunami rubble from other stretches of its north-east coast. But along the Fukushima Daiichi waterfront, the removal of debris deposited by the waves never really began.
The seawall, which failed to hold back the ocean on 11 March, is no more. Instead, piles of mesh sacks filled with rocks are all that separate the water from the exposed bowels of the reactors' turbine buildings, now a mass of twisted metal, shutters and ladders, where upended trucks sit in ditches filled with wreckage.
Work in this area of the plant is all but impossible. "Most of the workers here perform a two-hour shift in the morning and again in the afternoon," says Katsuhiko Iwaki, deputy manager of the Fukushima Daiichi stabilisation centre. "But there are areas where the dosages are so high they can only stay for two or three minutes … just enough time to connect a hose before their alarms signal it's time to leave."
Elsewhere, almost every spare patch of ground is covered in pipes and hoses, and sheets of wood and steel.
Avert your gaze from the gaping holes in the reactor walls and you could have stumbled upon an unwieldy building site. Only the mission here is not to rebuild, but to dismantle.
The success of the operation to remove melted nuclear fuel from the reactors – a process that will not start for 10 years – will depend on the hundreds of Tepco staff hunkered over computer screens in the plant's emergency control room. Voices rarely rise above a murmur as experts analyse data, while two large screens on a wall link the room, where the air is filtered, to the situation outside and Tepco's headquarters in Tokyo.
Takeshi Takahashi took over as plant manager in December after his predecessor was diagnosed with cancer (which is unrelated to the disaster). "We need to avoid major releases of radioactive materials of the kind we saw after the accident," he says. "We achieved cold shutdown in December, but we must ensure we keep making improvements because we still can't say for sure the facilities on site are totally trouble-free."
He refused to speculate on who was to blame for the accident before the government had completed its investigation, but he accepted criticism of his employer's transparency in the early days of the crisis. "We often hear we didn't communicate properly, and I apologise for that," he says. "It was never our intention to suppress information, but there was a chaotic time after the accident when we tended to neglect efficient communication."
Tepco appears to have adjusted its post-disaster mantra, at least in public. Last year its priority was to stabilise the reactors and prove the plant's destiny was back in the hands of its operator. The utility has since shifted its focus to the tens of thousands of relocated residents.
"I would like to apologise for the trouble we have caused local people," Takahashi says, unprompted. "We're doing our best to make it possible for evacuees to return home as soon as possible, but we have to put their safety first."
But no one can say when, or if, the stirrings of civic life will be seen in the deserted communities around Fukushima Daiichi. And amid the opprobrium directed at Tepco's corporate culture, it is easy to forget the victims include men, and a small number of women, who are witnessing the recovery effort from the inside.
Saori Kanesaki, who once guided visitors around Fukushima Daiichi, is one of 16,000 residents of Tomioka who were driven from their homes last March. "Before the accident it was my job to tell visitors that nuclear power was safe," says Kanesaki, who now works at the plant for a Tepco affiliate.
"But given the situation, if I were to tell them that now … I would be lying."
Estudo avaliou impacto das ondas em 28 pontos da região de Fukushima, e concluiu que a água atingiu o dobro da altura até agora dada como adquirida.
The Fukushima nuclear power plant. Photograph: AFP/Getty Images
Concern is growing that the Fukushima Daiichi nuclear power plant in Japan is no longer stable after temperature readings suggested one of its damaged reactors was reheating.
The plant's operator, Tokyo Electric Power (Tepco), said the temperature inside No 2 reactor – one of three that suffered meltdown after last year's earthquake and tsunami – may have reached 82C on Sunday.
Tepco said there was no evidence that the melted fuel inside had reached criticality. The utility reportedly increased the amount of cooling water being injected into the reactor along with a boric acid solution, which is used to prevent the fuel from undergoing sustained nuclear reactions.
Confirmation that the temperature has risen above 80C could force the government to reverse its declaration two months ago that the crippled plant was in a safe state known as cold shutdown.
Cold shutdown is achieved when the temperature inside the reactors remains below 100C and there is a significant reduction in radiation leaks. Given that Tepco assumes a margin of error of 20C, the actual temperature could have risen to 102C.
Plant workers are unable to take accurate readings of the temperature inside the damaged reactor because radiation levels are still too high for them to enter and examine the state of the melted fuel, which is thought to be resting at the bottom of the reactor's pressure vessel.
The result has been a series of wildly different readings: two other thermometers positioned at the bottom of No 2 reactor showed the temperature at 35C, local media reported.
Tepco said it did not know the cause of the apparent temperature rise, but speculated that it might be due to problems with the supply of coolant or a faulty thermometer.
"We believe the state of cold shutdown is being maintained," said Junichi Matsumoto, a company spokesman. "Rather than the actual temperature rising, we believe there is high possibility that the thermometer concerned is displaying erroneous data."
Tepco was forced to inject additional cooling water into the same reactor last week after the temperature started rising at the beginning of the month.
Según el Gobierno japonés, para que los reactores se consideren en estado de parada fría, el fondo de sus respectivas vasijas de contención debe permanecer de manera estable por debajo de los 100 grados centígrados.
Los parámetros establecidos por el Ejecutivo señalan, además, que la dosis anual de radiación en el perímetro de la planta debe ser de 1 milisievert o menos.
Noda, que se refirió a Fukushima durante el discurso de clausura de la temporada de sesiones parlamentarias, no detalló la fecha en la que se podría decretar la parada fría, aunque medios locales apuntan a que será tras una reunión programada para el 16 de diciembre.
Ese día el primer ministro tiene previsto presidir un encuentro con expertos de TEPCO y del Gobierno para analizar la situación en la maltrecha planta nuclear, dañada por el devastador tsunami del 11 de marzo.
Llevar los reactores a "parada fría" es uno de los grandes objetivos de la "hoja de ruta" elaborada por el Ejecutivo y TEPCO para resolver la crisis en la planta de Fukushima y una condición indispensable antes de que los 80.000 residentes evacuados en un radio de 20 kilómetros de la central puedan volver a sus casas.
Hoy, la Agencia de Seguridad Nuclear, dependiente del Gobierno, dio el visto bueno al plan de TEPCO para gestionar la central en los próximos tres años, que incluye medidas como la de mantener las inyecciones de agua en los reactores para mantener su temperatura o prevenir posible explosiones de hidrógeno.
La eléctrica, por otra parte, anunció hoy que en los próximos diez años recortará gastos operativos por valor de unos 2,64 billones de yenes (unos 34.000 millones de dólares), 103.000 millones de yenes más (unos 1.324 millones de dólares más) de lo inicialmente previsto.
El recorte de gastos es una medida necesaria para recibir las ayudas del Gobierno que le permitan pagar las indemnizaciones y afrontar el coste de las operaciones para desmantelar los reactores, algo para lo que se podrían necesitar más de 30 años. EFE
A Tokyo Electric Power (TEPCO), operadora da central nuclear de Fukushima, detectou uma fuga de cerca de 45 toneladas de água contaminada com estrôncio radioactivo, que poderão ter extravasado a fábrica, informou a cadeia de televisão NHK.
Os jornalistas que no sábado foram pela primeira vez autorizados a entrar na central nuclear de Fukushima assistiram a um «cenário devastador», com camiões virados ao contrário, lixo amontoado e prédios a ruir.
Nadezhda Prozherina / AFP / Getty Images
A photo released by the International Pacific Research Center at the University of Hawaii October 24, 2011 shows a Japanese fishing boat found by a Russian ship in the northwest Pacific. A fishing boat from Fukushima and other debris have been found in the Pacific at a location suggesting that flotsam from Japan's tsunami is drifting east faster than expected, researchers say
By Sandra McCulloch
VICTORIA — The largest items swept out to sea following the Japanese tsunami in March could arrive on the B.C. coastline within days, oceanographer Curt Ebbesmeyer predicted on Wednesday.
The main part of the 20-million-tonne debris field, equivalent in size to the state of California, isn’t expected until about 2014, but houses, fishboats and even small freighters could already be close to Canadian shores, Mr. Ebbesmeyer said.
“We just finished running a simulation with a drifter, a buoy that got lost in the area of the tsunami, and we find that the first of the debris would be here now,” Mr. Ebbesmeyer said.
Beachcombers along the west coast of B.C. should be on the lookout and report any unusual finds, he said.
Mr. Ebbesmeyer is a Seattle-based oceanographer, educated at the University of Washington, who tracks flotsam using computer models. He has consulted for multinational firms, working on projects such as the BP oil spill in the Gulf of Mexico.
The March 11 earthquake and tsunami in Japan prompted Mr. Ebbesmeyer and fellow oceanographer Jim Ingraham to run computer simulations on the path of debris carried out to sea by the tsunami.
Debris moves faster if it is exposed to the wind, Mr. Ebbesmeyer said.
A mostly submerged buoy measuring ocean currents can move 11 kilometres in a day, but a small fibreglass boat can travel three times faster, he said.
“People who base their results on satellite-tracking buoys get a slower speed than those of us who track Nike shoes and hockey gloves and airplane wings,” Mr. Ebbesmeyer said.
Researchers Nikolai Maximenko and Jan Hafner at the International Pacific Research Center in Hawaii are monitoring the debris field through computer models and ship reports.
Mr. Hafner said Wednesday that windblown flotsam isn’t part of his research. He said ocean currents will deliver a significant amount of plastics to this area in 2013 or 2014. The majority will remain in a North Pacific “garbage patch,” where swirling currents surround a vast amount of seaborne junk.
The crew of a cargo ship near Midway Island spotted an 18-foot vessel in the debris field, Mr. Hafner said.
The Japanese have immense respect for belongings such as fishing boats, said Mr. Ebbesmeyer, predicting an influx of Japanese tourists coming to B.C. to see the washed-up debris.
“When people find something on the beach, they are literally putting their hands on something that a family wants to know about,” he said.
A Japanese fishboat that washed ashore in Prince Rupert, B.C., several years ago has become a shrine to fishermen lost at sea, he said.
Tofino, B.C., beachcomber Barry Campbell can relate. A few years ago, he found a sealed bottle on the beach containing a note written by students at a Japanese school.
He wrote to the school “and got a huge stack of letters from each individual class, but most of them were in Japanese.”
Mr. Ebbesmeyer is asking anyone seeing floating debris of an unusual nature to take a photograph and send it to him through his website at flotsametrics.com.
A Transport Canada spokeswoman said contingency plans are in the works to deal with debris that might pose navigational hazards in Canadian waters.
Tokyo Electric Power (TEPCO) tomó ayer una muestra de la vasija de contención del reactor y detectó xenón 133 y 135, gases que podrían producirse por la fisión nuclear del uranio 235, informó la agencia Kyodo.
No obstante, la operadora y la Agencia japonesa de Seguridad Nuclear confirmaron que la densidad del xenón extraído es muy baja y que no se han producido grandes cambios en la temperatura y la presión del reactor, así como en los niveles de radiación del recinto.
Tras detectar el xenón, TEPCO procedió desde esta madrugada a inyectar durante una hora agua con ácido bórico en la segunda unidad de Fukushima Daiichi, en la que el pasado viernes instaló un sistema para succionar gases de la vasija de contención, a fin de filtrarlos y analizar su densidad.
Cerca de la parada fría
El reactor 2 de la maltrecha central, devastada por el terremoto y posterior tsunami que el pasado 11 de marzo asolaron el noreste del país, se encontraría cerca de alcanzar el estado de parada fría, según Kyodo, al mantener la temperatura de la unidad por debajo de los 100 grados centígrados desde hace más de un mes.
A mediados de octubre la operadora anunció que espera llevar a parada fría los reactores de la planta este mismo año, en lugar de la fecha de enero de 2012 prevista inicialmente, e indicó que los niveles de radiactividad que emite la deteriorada central se han reducido considerablemente en los últimos meses.
Además, confirmó que la temperatura de los tres reactores se encuentran por debajo de los 100 grados centígrados, lo que, de producirse de manera estable, supone llevarlos a parada fría.
La planta nuclear Fukushima Daiichi es el epicentro de la peor crisis nuclear mundial de los últimos 25 años, tras la de Chernóbil en 1986, desatada por la tragedia del 11 de marzo. EFEverde
Journalists keep close eye on Fukushima nuclear worker radiation exposure (Part 3)
The wide perception gap that has surfaced between Tokyo Electric Power Co., the operator of the tsunami-hit Fukushima No. 1 nuclear plant, the government and other parties has raised serious questions about the management of plant workers' radiation exposure.
Shortly after the plant was stricken with meltdowns and hydrogen explosions in March, Mainichi reporters, mainly those with the Tokyo City News Department, began interviewing workers struggling to bring the crippled facility under control.
Most of the workers are from Fukushima Prefecture, and many of them commute to the plant from shelters or dorms where they were taking refuge after their homes were badly damaged in March 11's natural disasters.
A 30-year-old worker for a sub-subcontractor said he had been told by an employee of the subcontractor, "We won't write down the amount of radiation you were exposed to during the latest work on your radiation management record. You don't have to worry about it."
Radiation exposure amounts and the results of regular medical exams are supposed to be stated clearly on each worker's radiation management record. If workers suffer from cancer in the future, there will be no proof of the causal relationship between their radiation exposure and the disease unless such data is included in their radiation management records, making them ineligible for workers' accident compensation benefits.
Further interviews with the utility, the government organizations concerned including the Health, Labor and Welfare Ministry, and other parties have revealed there was a wide perception gap among them over maximum exposure limits for workers.
Health ministry regulations stipulate that nuclear power station workers can be exposed to a maximum of 100 millisieverts over five years, and 50 millisieverts in a single year. However, in the case of an emergency such as a nuclear accident, they can be exposed to up to 100 millisieverts during work to bring the plant under control. In the Fukushima nuclear crisis, the ministry raised the upper limit to 250 millisieverts.
The ministry concluded that workers who are exposed to 100 to 250 millisieverts during efforts to tame the Fukushima nuclear crisis must be withdrawn from further work for five years on the grounds that the conventional regulations apply to the Fukushima crisis.
However, TEPCO was of the view that the conventional regulations do not apply to the work at the Fukushima plant, arguing that workers should not be deprived of employment for long periods. Because of this, the subcontractor omitted the levels of radiation workers were exposed to from their radiation management records.
"In the end, we are the ones who are going to be left holding the bag," a 28-year-old worker lamented in an interview with the Mainichi.
The Mainichi published an article about the omission of exposure data from the 30-year-old worker's radiation management record on the front page of its April 21 morning edition.
It was subsequently learned that at least one TEPCO employee had been exposed to more than 250 millisieverts, prompting the ministry to step up its radiation management instructions to the utility.
There have been some cases of plant workers being exposed to excessive levels of radiation during their work because of sloppy management. We are determined to continue to shed light on how workers' radiation exposure is being handled in an effort to improve their working environment. (By Satoshi Kusakabe, Takayuki Hakamada and Akiyo Ichikawa, Mainichi Shimbun)
A worker in protective gear uses a high-pressure washer to decontaminate the windows at Kashima Elementary School in the Fukushima Prefecture city of Minamisoma on Aug. 12. (Mainichi)The question of how much and where radioactive materials were dispersed by the hydrogen explosions at the Fukushima No. 1 nuclear plant have been of the utmost importance to residents of both Fukushima Prefecture and beyond, and one we began to pursue soon after the nuclear disaster started to unfold.
The government initially designated the area within a 20-kilometer radius of the power plant an evacuation zone, while those living between 20 kilometers and 30 kilometers from the plant were instructed to remain indoors. However, high levels of radiation were being detected even beyond those areas. A long-term advisory to stay indoors had not been a part of the government's disaster preparedness guidelines, and would pose too great a burden on residents. It seemed to us that a designation of evacuation zones based on actual radiation measurements was necessary.
That was when we came up with the idea of calculating cumulative radiation levels at various locations. At the time, radiation monitoring results released by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and municipal governments were limited to the amount of radiation detected in the atmosphere per hour (dosage rate). But since local residents would continue to be exposed to radiation, we felt it far more important to provide information on cumulative radiation levels.
When we appealed to MEXT to provide this information, we were told it was not something they could do right away. It was decided then that the Mainichi would crunch the cumulative radiation level numbers by adding together dosage rates released by public sources.
Between March 14 and March 21, the cumulative radiation level in the city of Fukushima reached 1770.7 microsieverts. The figure was 299.7 microsieverts for the Fukushima prefectural city of Iwaki and 34.1 microsieverts for the Tochigi Prefecture capital of Utsunomiya for the same period, and 33.2 microsieverts in the Ibaraki Prefecture capital city of Mito between March 15 and March 21. Having found the cumulative radiation in the city of Fukushima to exceed the average 1500 microsieverts of natural background radiation that we are normally exposed to annually, the Mainichi's Science and Environment News Department debated what to do with the information, concerned about the public response the information could spark.
Ultimately, we decided to release the information along with the explanation that cumulative radiation levels indicate how much radiation one would be exposed to if they stayed outdoors all day, and that radiation levels in general were trending downwards. We also added commentary from multiple experts that the radiation levels posed no health risks for people "stepping out to shop" for groceries, and published the information in the March 23 morning issue of the Mainichi's Japanese edition.
Following publication, we received inquiries from various municipal governments in Fukushima Prefecture, and were criticized by some readers for "causing panic among Fukushima city residents." We maintain, however, that by contributing information on cumulative radiation levels -- which until then had been largely ignored -- we helped residents come to their own conclusions on what to do next.
On March 25, MEXT began releasing cumulative radiation figures. Since then, it has gone on to conduct detailed monitoring of radiation levels, and has posted predicted cumulative radiation levels through March 2012.
Taku Nishikawa, Science and Environment News Department. (Mainichi)We still regret not having been able to predict that radioactive contamination would spread to the extent that it has. We keep asking ourselves if there was any way we could've sounded a more precise alarm when large volumes of radioactive materials were released on March 14 and March 15, as we continue working toward protecting the public from unnecessary exposure. (By Taku Nishikawa, Science and Environment News Department)
(This is part two of a six-part series on coverage of the Fukushima nuclear crisis.)
The front page of the March 13 morning issue of the Mainichi, reporting on an explosion at the Fukushima No. 1 Nuclear Power Plant. (Mainichi)The unprecedented disaster at the Fukushima No. 1 Nuclear Power Plant, in which fuel meltdowns were found to have taken place simultaneously at three reactors, poses a massive challenge to the media. Looking back, did we promptly deliver accurate information that could save the lives of the public? Reflecting upon our experiences gathering information from the disaster areas, as well as from the Prime Minister's Office, plant operator Tokyo Electric Power Co. (TEPCO), the Ministry of Economy, Trade and Industry's Nuclear and Industrial Safety Agency (NISA), and other groups and individuals, what can we say about our coverage of the ongoing crisis?
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Press conferences were held intermittently by TEPCO and NISA beginning March 11, when the nuclear disaster was triggered by the Great East Japan Earthquake and tsunami. As the safeguards meant to guarantee the safety of the nuclear power plant failed one after another, it was our task as reporters to discern the state of the plant with the limited information we had, motivated by a sense of impending danger to residents living in close proximity to the power plant. At the mercy of backtracking government and TEPCO officials, however, we were often at a loss as to how to confirm the legitimacy of the information we were given and how the information should be relayed to the public.
A little after 3:30 p.m. on March 12, images of the Fukushima No. 1 Nuclear Power Plant appeared on the screen of a television at TEPCO's head office in Tokyo's Uchisaiwaicho district. It appeared as though just the steel frame of the upper part of the No. 1 reactor building remained. The reporters grew alarmed. "Something's not right," one said.
However, even after seeing the footage, TEPCO's public relations officer stubbornly insisted: "We don't know what's going on. We're trying to confirm with those on the scene." Finally, at a press conference held four hours later, TEPCO admitted that there had been a hydrogen explosion at the plant's No. 1 reactor.
By that afternoon, radioactive cesium and iodine were detected in the power plant's surrounding areas. Koichiro Nakamura, then deputy director-general of NISA and the press officer for the agency, explained that it was possible that a reactor meltdown had taken place. Soon thereafter, Nakamura stopped appearing in press conferences. The new press officer refused to offer any further information, sticking to the line: "We can't discuss anything until the Prime Minister's Office has made an announcement." Subsequently, NISA avoided using the phrase "core meltdown," replacing it with either "fuel damage" or "core damage."
However, several months later, it emerged that NISA had previously asked power companies to fake support for nuclear power at a symposium, and on Aug. 10, approximately five months after the onset of the nuclear crisis, then NISA director Nobuaki Terasaka announced: "We recognized the possibility of a core meltdown soon after the incident began."
On March 12, NISA designated the Fukushima disaster a level 4 on the International Nuclear and Radiological Event Scale (INES), but a month later upgraded it to level 7, the worst level on the scale, which had until then been given only to Chernobyl. An understated announcement would be made, followed later by a revision. Statements concerning the nuclear disaster simply repeated this pattern.
So did TEPCO and the government respond appropriately to the crisis? I cannot shake the feeling that the damage could have been reined in far more than it has been. And slowly, through the efforts of the "Investigation Committee on the Accidents at the Fukushima Nuclear Power Station of Tokyo Electric Power Company" set up by the government, it's become clear what prevented officials from being more effective.
In preparation for a midterm report to be submitted by the end of the year, the committee has been conducting interviews with TEPCO and government officials. These interviews have revealed that it occurred to neither NISA nor to the Ministry of Education, Culture, Sports, Science and Technology (MEXT) to use a computer system called the System for Prediction of Environmental Emergency Dose Information (SPEEDI), in coming up with an evacuation plan. Furthermore, no one in NISA had even recognized the necessity of contacting neighboring countries, let alone raising the issue, before low-level radioactive water was dumped into the Pacific Ocean on April 4.
What I've gathered from my experiences trying to understand the disaster is that both TEPCO and the government have failed to look at the crisis from the point of view of the victims.
Norio Kanno, the mayor of the Fukushima Prefecture village of Iitate, lamented that he did not receive any information from the central government for a month or two after the nuclear disaster began, and suggested that it was because "hearts (of government officials) lacked concern for the disaster areas." There is anger directed toward media, too, which we as journalists must accept and learn from.
The basic mission of newspapers is to collect information in the field and deliver it accurately to the public. At the beginning of the nuclear crisis, however, we had no idea whether the information we had to work off of was accurate. In addition, many experts were divided on what they believed. Requests for permission to go on-site to the power plant to report were denied by TEPCO. When reporters haven't looked at the scene themselves, how are they to communicate the very limited information that they do have?
Junko Adachi, Science and Environment News Department (Mainichi)Settling of the ongoing crisis, including decontamination beyond the plant's borders, is expected to take many years. The investigation into the disaster's cause has just begun. The responsibility to stand on the side of those who receive the news, and write articles that will contribute to reconstruction and to shed light on the cause of the disaster weighs squarely on our shoulders. (By Junko Adachi, Science and Environment News Department)
(This is part one of a six-part series on coverage of the Fukushima nuclear crisis.)
Monday, Oct. 3, 2011
Tokyo Electric Power Co. on Saturday released an estimate saying that if the water injections cooling its stricken Fukushima power plant are halted again, the fuel rods could start melting within 38 hours, unleashing another wave of cancerous radioactive fallout.
If the plant is hit by another quake and tsunami as powerful as the March 11 disasters, resuming water injections into reactors 1, 2 and 3 will take three hours at most, the beleaguered utility said.
The cores melted down after the plant's electricity and backup cooling pumps were knocked out by the quake and tsunami.
The estimate said the temperature of the fuel — which is believed to have solidified into a solid mass at the bottom of the pressure vessels — will rise about 50 degrees each hour until it hits its melting point of 2,200 degrees in about 38 hours.
The reactors will then start emitting massive amounts of radioactive fallout, raising levels around the premises to over 10 millisieverts — the threshold for evacuation.
Tepco, however, did not assess the likelihood of newly melted fuel leaking from the pressure vessel — which holds the core — to the containment vessel — the next layer of protection before the buildings, which are damaged.
If any component of the current makeshift water-pumping system is lost, Tepco said it can resume injections in about 30 minutes by activating emergency pumps that have been installed at an elevated position nearby. In the event of multiple functions being lost, the utility projected it will require about three hours to resume water injections.
New evacuation zone
Japan is attempting to tweak its nuclear evacuation protocol by adding a new, smaller type of danger zone, disaster minister Goshi Hosono said Saturday.
The establishment of a "precautionary action zone" during a nuclear incident would require all residents inside it to immediately leave. The PAZ would be smaller than the government's so-called emergency planning zones.
Under current disaster preparedness guidelines, the radius of the EPZ is between 8 and 10 km. This is being reviewed in light of the Fukushima crisis, which eventually forced the government to set up a no-go zone with a 20-km radius around the plant, and another advisory zone 20 to 30 km away weeks later.
Don't worry, we won't post anything.
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