Engineer who oversaw nuclear plant hit by tsunami




17-2-1955 - 6-7-2013

Masao Yoshida, a nuclear engineer who took charge of the Fukushima Daiichi power plant two years ago as multiple reactors spiralled out of control after a tsunami, but who ultimately failed to prevent the world's worst nuclear disaster since Chernobyl, has died aged 58.

Yoshida had been chief manager at Fukushima Daiichi for just nine months when a huge tsunami inundated the site on March 11, 2011, knocking out vital cooling systems to the plant's six reactors. Eventually, hydrogen explosions and fuel meltdowns occurred at three reactors, releasing radioactive matter into the environment.

Although the company was widely criticised for its handling of the disaster, which forced more than 100,000 people from their homes, Yoshida won praise for his effort to minimise the damage.

He has been faulted, however, for failing to invest in adequate tsunami walls at the company's nuclear power plants when he was head of nuclear facilities. Yoshida later apologised to reporters, saying he had been "too lax" in his assumptions of how big a tsunami might hit the coastal plant.

Yoshida took a leave from plant operator Tokyo Electric Power in late 2011 after receiving a diagnosis of oesophageal cancer. Experts have said his illness was not a result of radiation exposure from the accident, given how quickly it came on.

Survivors include his wife, Yoko, and three sons.

When the tsunami hit, Yoshida took command from inside a fortified bunker at the plant. In video footage of the room released by Tokyo Electric last year, Yoshida can be seen pushing his workers to hook up water hoses, at times tearfully apologising to teams he sent out to check on the stricken reactors.

At one point, he ignores orders that he is told come directly from then prime minister Naoto Kan to stop injecting seawater into one of the reactors, a last-ditch measure taken by plant workers to try to cool it. (Kan later denied that he had given such orders and suggested that Tokyo Electric officials had probably misunderstood.)

Yoshida later offers to lead a "suicide mission" with other older officials to try pumping water into another reactor but is dissuaded. And as officials warn that core

meltdowns have most likely started, he directs men to leave the reactors but stays in the bunker. Yoshida later said that the thought of abandoning the plant never occurred to him.

Masao Yoshida was born on February 17, 1955, in Osaka, Japan, to a family that ran a small advertising firm. An only child, he spent much of his middle and high school years practising the Japanese martial art kendo. He went on to study nuclear engineering at the Tokyo Institute of Technology and joined Tokyo Electric after graduate school.

He worked his way up through the company's nuclear power division, overseeing its nuclear facilities from 2007 until being appointed chief of Fukushima Daiichi in June 2010. Following the tsunami he led the disaster response for eight months before going on sick leave.

On his last day at Fukushima Daiichi in December 2011, according to a book on Yoshida by Kadota Ryusho, he again rallied his troops.

"You still have a difficult road ahead, but I know you will overcome," Yoshida is quoted as saying. "I promise to do my best to return."

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